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v6.8
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Endpoint Function Driver to implement Non-Transparent Bridge functionality
   4 *
   5 * Copyright (C) 2020 Texas Instruments
   6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
   7 */
   8
   9/*
  10 * The PCI NTB function driver configures the SoC with multiple PCIe Endpoint
  11 * (EP) controller instances (see diagram below) in such a way that
  12 * transactions from one EP controller are routed to the other EP controller.
  13 * Once PCI NTB function driver configures the SoC with multiple EP instances,
  14 * HOST1 and HOST2 can communicate with each other using SoC as a bridge.
  15 *
  16 *    +-------------+                                   +-------------+
  17 *    |             |                                   |             |
  18 *    |    HOST1    |                                   |    HOST2    |
  19 *    |             |                                   |             |
  20 *    +------^------+                                   +------^------+
  21 *           |                                                 |
  22 *           |                                                 |
  23 * +---------|-------------------------------------------------|---------+
  24 * |  +------v------+                                   +------v------+  |
  25 * |  |             |                                   |             |  |
  26 * |  |     EP      |                                   |     EP      |  |
  27 * |  | CONTROLLER1 |                                   | CONTROLLER2 |  |
  28 * |  |             <----------------------------------->             |  |
  29 * |  |             |                                   |             |  |
  30 * |  |             |                                   |             |  |
  31 * |  |             |  SoC With Multiple EP Instances   |             |  |
  32 * |  |             |  (Configured using NTB Function)  |             |  |
  33 * |  +-------------+                                   +-------------+  |
  34 * +---------------------------------------------------------------------+
  35 */
  36
  37#include <linux/delay.h>
  38#include <linux/io.h>
  39#include <linux/module.h>
  40#include <linux/slab.h>
  41
  42#include <linux/pci-epc.h>
  43#include <linux/pci-epf.h>
  44
  45static struct workqueue_struct *kpcintb_workqueue;
  46
  47#define COMMAND_CONFIGURE_DOORBELL	1
  48#define COMMAND_TEARDOWN_DOORBELL	2
  49#define COMMAND_CONFIGURE_MW		3
  50#define COMMAND_TEARDOWN_MW		4
  51#define COMMAND_LINK_UP			5
  52#define COMMAND_LINK_DOWN		6
  53
  54#define COMMAND_STATUS_OK		1
  55#define COMMAND_STATUS_ERROR		2
  56
  57#define LINK_STATUS_UP			BIT(0)
  58
  59#define SPAD_COUNT			64
  60#define DB_COUNT			4
  61#define NTB_MW_OFFSET			2
  62#define DB_COUNT_MASK			GENMASK(15, 0)
  63#define MSIX_ENABLE			BIT(16)
  64#define MAX_DB_COUNT			32
  65#define MAX_MW				4
  66
  67enum epf_ntb_bar {
  68	BAR_CONFIG,
  69	BAR_PEER_SPAD,
  70	BAR_DB_MW1,
  71	BAR_MW2,
  72	BAR_MW3,
  73	BAR_MW4,
  74};
  75
  76struct epf_ntb {
  77	u32 num_mws;
  78	u32 db_count;
  79	u32 spad_count;
  80	struct pci_epf *epf;
  81	u64 mws_size[MAX_MW];
  82	struct config_group group;
  83	struct epf_ntb_epc *epc[2];
  84};
  85
  86#define to_epf_ntb(epf_group) container_of((epf_group), struct epf_ntb, group)
  87
  88struct epf_ntb_epc {
  89	u8 func_no;
  90	u8 vfunc_no;
  91	bool linkup;
  92	bool is_msix;
  93	int msix_bar;
  94	u32 spad_size;
  95	struct pci_epc *epc;
  96	struct epf_ntb *epf_ntb;
  97	void __iomem *mw_addr[6];
  98	size_t msix_table_offset;
  99	struct epf_ntb_ctrl *reg;
 100	struct pci_epf_bar *epf_bar;
 101	enum pci_barno epf_ntb_bar[6];
 102	struct delayed_work cmd_handler;
 103	enum pci_epc_interface_type type;
 104	const struct pci_epc_features *epc_features;
 105};
 106
 107struct epf_ntb_ctrl {
 108	u32	command;
 109	u32	argument;
 110	u16	command_status;
 111	u16	link_status;
 112	u32	topology;
 113	u64	addr;
 114	u64	size;
 115	u32	num_mws;
 116	u32	mw1_offset;
 117	u32	spad_offset;
 118	u32	spad_count;
 119	u32	db_entry_size;
 120	u32	db_data[MAX_DB_COUNT];
 121	u32	db_offset[MAX_DB_COUNT];
 122} __packed;
 123
 124static struct pci_epf_header epf_ntb_header = {
 125	.vendorid	= PCI_ANY_ID,
 126	.deviceid	= PCI_ANY_ID,
 127	.baseclass_code	= PCI_BASE_CLASS_MEMORY,
 128	.interrupt_pin	= PCI_INTERRUPT_INTA,
 129};
 130
 131/**
 132 * epf_ntb_link_up() - Raise link_up interrupt to both the hosts
 133 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 134 * @link_up: true or false indicating Link is UP or Down
 135 *
 136 * Once NTB function in HOST1 and the NTB function in HOST2 invoke
 137 * ntb_link_enable(), this NTB function driver will trigger a link event to
 138 * the NTB client in both the hosts.
 139 */
 140static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
 141{
 142	enum pci_epc_interface_type type;
 
 143	struct epf_ntb_epc *ntb_epc;
 144	struct epf_ntb_ctrl *ctrl;
 145	unsigned int irq_type;
 146	struct pci_epc *epc;
 147	u8 func_no, vfunc_no;
 148	bool is_msix;
 
 149	int ret;
 150
 151	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
 152		ntb_epc = ntb->epc[type];
 153		epc = ntb_epc->epc;
 154		func_no = ntb_epc->func_no;
 155		vfunc_no = ntb_epc->vfunc_no;
 156		is_msix = ntb_epc->is_msix;
 157		ctrl = ntb_epc->reg;
 158		if (link_up)
 159			ctrl->link_status |= LINK_STATUS_UP;
 160		else
 161			ctrl->link_status &= ~LINK_STATUS_UP;
 162		irq_type = is_msix ? PCI_IRQ_MSIX : PCI_IRQ_MSI;
 163		ret = pci_epc_raise_irq(epc, func_no, vfunc_no, irq_type, 1);
 164		if (ret) {
 165			dev_err(&epc->dev,
 166				"%s intf: Failed to raise Link Up IRQ\n",
 167				pci_epc_interface_string(type));
 168			return ret;
 169		}
 170	}
 171
 172	return 0;
 173}
 174
 175/**
 176 * epf_ntb_configure_mw() - Configure the Outbound Address Space for one host
 177 *   to access the memory window of other host
 178 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 179 * @type: PRIMARY interface or SECONDARY interface
 180 * @mw: Index of the memory window (either 0, 1, 2 or 3)
 181 *
 182 * +-----------------+    +---->+----------------+-----------+-----------------+
 183 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
 184 * +-----------------+    |     +----------------+           +-----------------+
 185 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
 186 * +-----------------+----+     +----------------+         | |                 |
 187 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
 188 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
 189 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
 190 * +-----------------+    |     |----------------+     | |   |                 |
 191 * |       BAR4      |    |     |                |     | |   +-----------------+
 192 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
 193 * |       BAR5      |    |     |                |   | |     +-----------------+
 194 * +-----------------+    +---->-----------------+   | |     |                 |
 195 *   EP CONTROLLER 1            |                |   | |     +-----------------+
 196 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
 197 *                              +----------------+   |       +-----------------+
 198 *                      (A)      EP CONTROLLER 2     |       |                 |
 199 *                                 (OB SPACE)        |       |                 |
 200 *                                                   +------->      MW1        |
 201 *                                                           |                 |
 202 *                                                           |                 |
 203 *                                                   (B)     +-----------------+
 204 *                                                           |                 |
 205 *                                                           |                 |
 206 *                                                           |                 |
 207 *                                                           |                 |
 208 *                                                           |                 |
 209 *                                                           +-----------------+
 210 *                                                           PCI Address Space
 211 *                                                           (Managed by HOST2)
 212 *
 213 * This function performs stage (B) in the above diagram (see MW1) i.e., map OB
 214 * address space of memory window to PCI address space.
 215 *
 216 * This operation requires 3 parameters
 217 *  1) Address in the outbound address space
 218 *  2) Address in the PCI Address space
 219 *  3) Size of the address region to be mapped
 220 *
 221 * The address in the outbound address space (for MW1, MW2, MW3 and MW4) is
 222 * stored in epf_bar corresponding to BAR_DB_MW1 for MW1 and BAR_MW2, BAR_MW3
 223 * BAR_MW4 for rest of the BARs of epf_ntb_epc that is connected to HOST1. This
 224 * is populated in epf_ntb_alloc_peer_mem() in this driver.
 225 *
 226 * The address and size of the PCI address region that has to be mapped would
 227 * be provided by HOST2 in ctrl->addr and ctrl->size of epf_ntb_epc that is
 228 * connected to HOST2.
 229 *
 230 * Please note Memory window1 (MW1) and Doorbell registers together will be
 231 * mapped to a single BAR (BAR2) above for 32-bit BARs. The exact BAR that's
 232 * used for Memory window (MW) can be obtained from epf_ntb_bar[BAR_DB_MW1],
 233 * epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2].
 234 */
 235static int epf_ntb_configure_mw(struct epf_ntb *ntb,
 236				enum pci_epc_interface_type type, u32 mw)
 237{
 238	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 239	struct pci_epf_bar *peer_epf_bar;
 240	enum pci_barno peer_barno;
 241	struct epf_ntb_ctrl *ctrl;
 242	phys_addr_t phys_addr;
 243	u8 func_no, vfunc_no;
 244	struct pci_epc *epc;
 245	u64 addr, size;
 246	int ret = 0;
 
 247
 248	ntb_epc = ntb->epc[type];
 249	epc = ntb_epc->epc;
 250
 251	peer_ntb_epc = ntb->epc[!type];
 252	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
 253	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 254
 255	phys_addr = peer_epf_bar->phys_addr;
 256	ctrl = ntb_epc->reg;
 257	addr = ctrl->addr;
 258	size = ctrl->size;
 259	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
 260		phys_addr += ctrl->mw1_offset;
 261
 262	if (size > ntb->mws_size[mw]) {
 263		dev_err(&epc->dev,
 264			"%s intf: MW: %d Req Sz:%llxx > Supported Sz:%llx\n",
 265			pci_epc_interface_string(type), mw, size,
 266			ntb->mws_size[mw]);
 267		ret = -EINVAL;
 268		goto err_invalid_size;
 269	}
 270
 271	func_no = ntb_epc->func_no;
 272	vfunc_no = ntb_epc->vfunc_no;
 273
 274	ret = pci_epc_map_addr(epc, func_no, vfunc_no, phys_addr, addr, size);
 275	if (ret)
 276		dev_err(&epc->dev,
 277			"%s intf: Failed to map memory window %d address\n",
 278			pci_epc_interface_string(type), mw);
 279
 280err_invalid_size:
 281
 282	return ret;
 283}
 284
 285/**
 286 * epf_ntb_teardown_mw() - Teardown the configured OB ATU
 287 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 288 * @type: PRIMARY interface or SECONDARY interface
 289 * @mw: Index of the memory window (either 0, 1, 2 or 3)
 290 *
 291 * Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
 292 * pci_epc_unmap_addr()
 293 */
 294static void epf_ntb_teardown_mw(struct epf_ntb *ntb,
 295				enum pci_epc_interface_type type, u32 mw)
 296{
 297	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 298	struct pci_epf_bar *peer_epf_bar;
 299	enum pci_barno peer_barno;
 300	struct epf_ntb_ctrl *ctrl;
 301	phys_addr_t phys_addr;
 302	u8 func_no, vfunc_no;
 303	struct pci_epc *epc;
 
 304
 305	ntb_epc = ntb->epc[type];
 306	epc = ntb_epc->epc;
 307
 308	peer_ntb_epc = ntb->epc[!type];
 309	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
 310	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 311
 312	phys_addr = peer_epf_bar->phys_addr;
 313	ctrl = ntb_epc->reg;
 314	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
 315		phys_addr += ctrl->mw1_offset;
 316	func_no = ntb_epc->func_no;
 317	vfunc_no = ntb_epc->vfunc_no;
 318
 319	pci_epc_unmap_addr(epc, func_no, vfunc_no, phys_addr);
 320}
 321
 322/**
 323 * epf_ntb_configure_msi() - Map OB address space to MSI address
 324 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 325 * @type: PRIMARY interface or SECONDARY interface
 326 * @db_count: Number of doorbell interrupts to map
 327 *
 328 *+-----------------+    +----->+----------------+-----------+-----------------+
 329 *|       BAR0      |    |      |   Doorbell 1   +---+------->   MSI ADDRESS   |
 330 *+-----------------+    |      +----------------+   |       +-----------------+
 331 *|       BAR1      |    |      |   Doorbell 2   +---+       |                 |
 332 *+-----------------+----+      +----------------+   |       |                 |
 333 *|       BAR2      |           |   Doorbell 3   +---+       |                 |
 334 *+-----------------+----+      +----------------+   |       |                 |
 335 *|       BAR3      |    |      |   Doorbell 4   +---+       |                 |
 336 *+-----------------+    |      |----------------+           |                 |
 337 *|       BAR4      |    |      |                |           |                 |
 338 *+-----------------+    |      |      MW1       |           |                 |
 339 *|       BAR5      |    |      |                |           |                 |
 340 *+-----------------+    +----->-----------------+           |                 |
 341 *  EP CONTROLLER 1             |                |           |                 |
 342 *                              |                |           |                 |
 343 *                              +----------------+           +-----------------+
 344 *                     (A)       EP CONTROLLER 2             |                 |
 345 *                                 (OB SPACE)                |                 |
 346 *                                                           |      MW1        |
 347 *                                                           |                 |
 348 *                                                           |                 |
 349 *                                                   (B)     +-----------------+
 350 *                                                           |                 |
 351 *                                                           |                 |
 352 *                                                           |                 |
 353 *                                                           |                 |
 354 *                                                           |                 |
 355 *                                                           +-----------------+
 356 *                                                           PCI Address Space
 357 *                                                           (Managed by HOST2)
 358 *
 359 *
 360 * This function performs stage (B) in the above diagram (see Doorbell 1,
 361 * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
 362 * doorbell to MSI address in PCI address space.
 363 *
 364 * This operation requires 3 parameters
 365 *  1) Address reserved for doorbell in the outbound address space
 366 *  2) MSI-X address in the PCIe Address space
 367 *  3) Number of MSI-X interrupts that has to be configured
 368 *
 369 * The address in the outbound address space (for the Doorbell) is stored in
 370 * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
 371 * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
 372 * with address for MW1.
 373 *
 374 * pci_epc_map_msi_irq() takes the MSI address from MSI capability register
 375 * and maps the OB address (obtained in epf_ntb_alloc_peer_mem()) to the MSI
 376 * address.
 377 *
 378 * epf_ntb_configure_msi() also stores the MSI data to raise each interrupt
 379 * in db_data of the peer's control region. This helps the peer to raise
 380 * doorbell of the other host by writing db_data to the BAR corresponding to
 381 * BAR_DB_MW1.
 382 */
 383static int epf_ntb_configure_msi(struct epf_ntb *ntb,
 384				 enum pci_epc_interface_type type, u16 db_count)
 385{
 386	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 387	u32 db_entry_size, db_data, db_offset;
 388	struct pci_epf_bar *peer_epf_bar;
 389	struct epf_ntb_ctrl *peer_ctrl;
 390	enum pci_barno peer_barno;
 391	phys_addr_t phys_addr;
 392	u8 func_no, vfunc_no;
 393	struct pci_epc *epc;
 
 394	int ret, i;
 395
 396	ntb_epc = ntb->epc[type];
 397	epc = ntb_epc->epc;
 398
 399	peer_ntb_epc = ntb->epc[!type];
 400	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
 401	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 402	peer_ctrl = peer_ntb_epc->reg;
 403	db_entry_size = peer_ctrl->db_entry_size;
 404
 405	phys_addr = peer_epf_bar->phys_addr;
 406	func_no = ntb_epc->func_no;
 407	vfunc_no = ntb_epc->vfunc_no;
 408
 409	ret = pci_epc_map_msi_irq(epc, func_no, vfunc_no, phys_addr, db_count,
 410				  db_entry_size, &db_data, &db_offset);
 411	if (ret) {
 412		dev_err(&epc->dev, "%s intf: Failed to map MSI IRQ\n",
 413			pci_epc_interface_string(type));
 414		return ret;
 415	}
 416
 417	for (i = 0; i < db_count; i++) {
 418		peer_ctrl->db_data[i] = db_data | i;
 419		peer_ctrl->db_offset[i] = db_offset;
 420	}
 421
 422	return 0;
 423}
 424
 425/**
 426 * epf_ntb_configure_msix() - Map OB address space to MSI-X address
 427 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 428 * @type: PRIMARY interface or SECONDARY interface
 429 * @db_count: Number of doorbell interrupts to map
 430 *
 431 *+-----------------+    +----->+----------------+-----------+-----------------+
 432 *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI-X ADDRESS 1 |
 433 *+-----------------+    |      +----------------+           +-----------------+
 434 *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
 435 *+-----------------+----+      +----------------+         | |                 |
 436 *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
 437 *+-----------------+----+      +----------------+       | +-> MSI-X ADDRESS 2 |
 438 *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
 439 *+-----------------+    |      |----------------+     | |   |                 |
 440 *|       BAR4      |    |      |                |     | |   +-----------------+
 441 *+-----------------+    |      |      MW1       +     | +-->+ MSI-X ADDRESS 3||
 442 *|       BAR5      |    |      |                |     |     +-----------------+
 443 *+-----------------+    +----->-----------------+     |     |                 |
 444 *  EP CONTROLLER 1             |                |     |     +-----------------+
 445 *                              |                |     +---->+ MSI-X ADDRESS 4 |
 446 *                              +----------------+           +-----------------+
 447 *                     (A)       EP CONTROLLER 2             |                 |
 448 *                                 (OB SPACE)                |                 |
 449 *                                                           |      MW1        |
 450 *                                                           |                 |
 451 *                                                           |                 |
 452 *                                                   (B)     +-----------------+
 453 *                                                           |                 |
 454 *                                                           |                 |
 455 *                                                           |                 |
 456 *                                                           |                 |
 457 *                                                           |                 |
 458 *                                                           +-----------------+
 459 *                                                           PCI Address Space
 460 *                                                           (Managed by HOST2)
 461 *
 462 * This function performs stage (B) in the above diagram (see Doorbell 1,
 463 * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
 464 * doorbell to MSI-X address in PCI address space.
 465 *
 466 * This operation requires 3 parameters
 467 *  1) Address reserved for doorbell in the outbound address space
 468 *  2) MSI-X address in the PCIe Address space
 469 *  3) Number of MSI-X interrupts that has to be configured
 470 *
 471 * The address in the outbound address space (for the Doorbell) is stored in
 472 * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
 473 * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
 474 * with address for MW1.
 475 *
 476 * The MSI-X address is in the MSI-X table of EP CONTROLLER 2 and
 477 * the count of doorbell is in ctrl->argument of epf_ntb_epc that is connected
 478 * to HOST2. MSI-X table is stored memory mapped to ntb_epc->msix_bar and the
 479 * offset is in ntb_epc->msix_table_offset. From this epf_ntb_configure_msix()
 480 * gets the MSI-X address and data.
 481 *
 482 * epf_ntb_configure_msix() also stores the MSI-X data to raise each interrupt
 483 * in db_data of the peer's control region. This helps the peer to raise
 484 * doorbell of the other host by writing db_data to the BAR corresponding to
 485 * BAR_DB_MW1.
 486 */
 487static int epf_ntb_configure_msix(struct epf_ntb *ntb,
 488				  enum pci_epc_interface_type type,
 489				  u16 db_count)
 490{
 491	const struct pci_epc_features *epc_features;
 492	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 493	struct pci_epf_bar *peer_epf_bar, *epf_bar;
 494	struct pci_epf_msix_tbl *msix_tbl;
 495	struct epf_ntb_ctrl *peer_ctrl;
 496	u32 db_entry_size, msg_data;
 497	enum pci_barno peer_barno;
 498	phys_addr_t phys_addr;
 499	u8 func_no, vfunc_no;
 500	struct pci_epc *epc;
 501	size_t align;
 502	u64 msg_addr;
 
 503	int ret, i;
 504
 505	ntb_epc = ntb->epc[type];
 506	epc = ntb_epc->epc;
 507
 508	epf_bar = &ntb_epc->epf_bar[ntb_epc->msix_bar];
 509	msix_tbl = epf_bar->addr + ntb_epc->msix_table_offset;
 510
 511	peer_ntb_epc = ntb->epc[!type];
 512	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
 513	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 514	phys_addr = peer_epf_bar->phys_addr;
 515	peer_ctrl = peer_ntb_epc->reg;
 516	epc_features = ntb_epc->epc_features;
 517	align = epc_features->align;
 518
 519	func_no = ntb_epc->func_no;
 520	vfunc_no = ntb_epc->vfunc_no;
 521	db_entry_size = peer_ctrl->db_entry_size;
 522
 523	for (i = 0; i < db_count; i++) {
 524		msg_addr = ALIGN_DOWN(msix_tbl[i].msg_addr, align);
 525		msg_data = msix_tbl[i].msg_data;
 526		ret = pci_epc_map_addr(epc, func_no, vfunc_no, phys_addr, msg_addr,
 527				       db_entry_size);
 528		if (ret) {
 529			dev_err(&epc->dev,
 530				"%s intf: Failed to configure MSI-X IRQ\n",
 531				pci_epc_interface_string(type));
 532			return ret;
 533		}
 534		phys_addr = phys_addr + db_entry_size;
 535		peer_ctrl->db_data[i] = msg_data;
 536		peer_ctrl->db_offset[i] = msix_tbl[i].msg_addr & (align - 1);
 537	}
 538	ntb_epc->is_msix = true;
 539
 540	return 0;
 541}
 542
 543/**
 544 * epf_ntb_configure_db() - Configure the Outbound Address Space for one host
 545 *   to ring the doorbell of other host
 546 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 547 * @type: PRIMARY interface or SECONDARY interface
 548 * @db_count: Count of the number of doorbells that has to be configured
 549 * @msix: Indicates whether MSI-X or MSI should be used
 550 *
 551 * Invokes epf_ntb_configure_msix() or epf_ntb_configure_msi() required for
 552 * one HOST to ring the doorbell of other HOST.
 553 */
 554static int epf_ntb_configure_db(struct epf_ntb *ntb,
 555				enum pci_epc_interface_type type,
 556				u16 db_count, bool msix)
 557{
 558	struct epf_ntb_epc *ntb_epc;
 559	struct pci_epc *epc;
 560	int ret;
 561
 562	if (db_count > MAX_DB_COUNT)
 563		return -EINVAL;
 564
 565	ntb_epc = ntb->epc[type];
 566	epc = ntb_epc->epc;
 567
 568	if (msix)
 569		ret = epf_ntb_configure_msix(ntb, type, db_count);
 570	else
 571		ret = epf_ntb_configure_msi(ntb, type, db_count);
 572
 573	if (ret)
 574		dev_err(&epc->dev, "%s intf: Failed to configure DB\n",
 575			pci_epc_interface_string(type));
 576
 577	return ret;
 578}
 579
 580/**
 581 * epf_ntb_teardown_db() - Unmap address in OB address space to MSI/MSI-X
 582 *   address
 583 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 584 * @type: PRIMARY interface or SECONDARY interface
 585 *
 586 * Invoke pci_epc_unmap_addr() to unmap OB address to MSI/MSI-X address.
 587 */
 588static void
 589epf_ntb_teardown_db(struct epf_ntb *ntb, enum pci_epc_interface_type type)
 590{
 591	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 592	struct pci_epf_bar *peer_epf_bar;
 593	enum pci_barno peer_barno;
 594	phys_addr_t phys_addr;
 595	u8 func_no, vfunc_no;
 596	struct pci_epc *epc;
 
 597
 598	ntb_epc = ntb->epc[type];
 599	epc = ntb_epc->epc;
 600
 601	peer_ntb_epc = ntb->epc[!type];
 602	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
 603	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 604	phys_addr = peer_epf_bar->phys_addr;
 605	func_no = ntb_epc->func_no;
 606	vfunc_no = ntb_epc->vfunc_no;
 607
 608	pci_epc_unmap_addr(epc, func_no, vfunc_no, phys_addr);
 609}
 610
 611/**
 612 * epf_ntb_cmd_handler() - Handle commands provided by the NTB Host
 613 * @work: work_struct for the two epf_ntb_epc (PRIMARY and SECONDARY)
 614 *
 615 * Workqueue function that gets invoked for the two epf_ntb_epc
 616 * periodically (once every 5ms) to see if it has received any commands
 617 * from NTB host. The host can send commands to configure doorbell or
 618 * configure memory window or to update link status.
 619 */
 620static void epf_ntb_cmd_handler(struct work_struct *work)
 621{
 622	enum pci_epc_interface_type type;
 623	struct epf_ntb_epc *ntb_epc;
 624	struct epf_ntb_ctrl *ctrl;
 625	u32 command, argument;
 626	struct epf_ntb *ntb;
 627	struct device *dev;
 628	u16 db_count;
 629	bool is_msix;
 630	int ret;
 631
 632	ntb_epc = container_of(work, struct epf_ntb_epc, cmd_handler.work);
 633	ctrl = ntb_epc->reg;
 634	command = ctrl->command;
 635	if (!command)
 636		goto reset_handler;
 637	argument = ctrl->argument;
 638
 639	ctrl->command = 0;
 640	ctrl->argument = 0;
 641
 642	ctrl = ntb_epc->reg;
 643	type = ntb_epc->type;
 644	ntb = ntb_epc->epf_ntb;
 645	dev = &ntb->epf->dev;
 646
 647	switch (command) {
 648	case COMMAND_CONFIGURE_DOORBELL:
 649		db_count = argument & DB_COUNT_MASK;
 650		is_msix = argument & MSIX_ENABLE;
 651		ret = epf_ntb_configure_db(ntb, type, db_count, is_msix);
 652		if (ret < 0)
 653			ctrl->command_status = COMMAND_STATUS_ERROR;
 654		else
 655			ctrl->command_status = COMMAND_STATUS_OK;
 656		break;
 657	case COMMAND_TEARDOWN_DOORBELL:
 658		epf_ntb_teardown_db(ntb, type);
 659		ctrl->command_status = COMMAND_STATUS_OK;
 660		break;
 661	case COMMAND_CONFIGURE_MW:
 662		ret = epf_ntb_configure_mw(ntb, type, argument);
 663		if (ret < 0)
 664			ctrl->command_status = COMMAND_STATUS_ERROR;
 665		else
 666			ctrl->command_status = COMMAND_STATUS_OK;
 667		break;
 668	case COMMAND_TEARDOWN_MW:
 669		epf_ntb_teardown_mw(ntb, type, argument);
 670		ctrl->command_status = COMMAND_STATUS_OK;
 671		break;
 672	case COMMAND_LINK_UP:
 673		ntb_epc->linkup = true;
 674		if (ntb->epc[PRIMARY_INTERFACE]->linkup &&
 675		    ntb->epc[SECONDARY_INTERFACE]->linkup) {
 676			ret = epf_ntb_link_up(ntb, true);
 677			if (ret < 0)
 678				ctrl->command_status = COMMAND_STATUS_ERROR;
 679			else
 680				ctrl->command_status = COMMAND_STATUS_OK;
 681			goto reset_handler;
 682		}
 683		ctrl->command_status = COMMAND_STATUS_OK;
 684		break;
 685	case COMMAND_LINK_DOWN:
 686		ntb_epc->linkup = false;
 687		ret = epf_ntb_link_up(ntb, false);
 688		if (ret < 0)
 689			ctrl->command_status = COMMAND_STATUS_ERROR;
 690		else
 691			ctrl->command_status = COMMAND_STATUS_OK;
 692		break;
 693	default:
 694		dev_err(dev, "%s intf UNKNOWN command: %d\n",
 695			pci_epc_interface_string(type), command);
 696		break;
 697	}
 698
 699reset_handler:
 700	queue_delayed_work(kpcintb_workqueue, &ntb_epc->cmd_handler,
 701			   msecs_to_jiffies(5));
 702}
 703
 704/**
 705 * epf_ntb_peer_spad_bar_clear() - Clear Peer Scratchpad BAR
 706 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
 707 *	     address.
 708 *
 709 *+-----------------+------->+------------------+        +-----------------+
 710 *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 711 *+-----------------+----+   +------------------+<-------+-----------------+
 712 *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 713 *+-----------------+    +-->+------------------+<-------+-----------------+
 714 *|       BAR2      |            Local Memory            |       BAR2      |
 715 *+-----------------+                                    +-----------------+
 716 *|       BAR3      |                                    |       BAR3      |
 717 *+-----------------+                                    +-----------------+
 718 *|       BAR4      |                                    |       BAR4      |
 719 *+-----------------+                                    +-----------------+
 720 *|       BAR5      |                                    |       BAR5      |
 721 *+-----------------+                                    +-----------------+
 722 *  EP CONTROLLER 1                                        EP CONTROLLER 2
 723 *
 724 * Clear BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
 725 * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
 726 * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
 727 * This function can get the exact BAR used for peer scratchpad from
 728 * epf_ntb_bar[BAR_PEER_SPAD].
 729 *
 730 * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
 731 * gets the address of peer scratchpad from
 732 * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
 733 */
 734static void epf_ntb_peer_spad_bar_clear(struct epf_ntb_epc *ntb_epc)
 735{
 736	struct pci_epf_bar *epf_bar;
 737	enum pci_barno barno;
 738	u8 func_no, vfunc_no;
 739	struct pci_epc *epc;
 
 740
 741	epc = ntb_epc->epc;
 742	func_no = ntb_epc->func_no;
 743	vfunc_no = ntb_epc->vfunc_no;
 744	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
 745	epf_bar = &ntb_epc->epf_bar[barno];
 746	pci_epc_clear_bar(epc, func_no, vfunc_no, epf_bar);
 747}
 748
 749/**
 750 * epf_ntb_peer_spad_bar_set() - Set peer scratchpad BAR
 751 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 752 * @type: PRIMARY interface or SECONDARY interface
 753 *
 754 *+-----------------+------->+------------------+        +-----------------+
 755 *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 756 *+-----------------+----+   +------------------+<-------+-----------------+
 757 *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 758 *+-----------------+    +-->+------------------+<-------+-----------------+
 759 *|       BAR2      |            Local Memory            |       BAR2      |
 760 *+-----------------+                                    +-----------------+
 761 *|       BAR3      |                                    |       BAR3      |
 762 *+-----------------+                                    +-----------------+
 763 *|       BAR4      |                                    |       BAR4      |
 764 *+-----------------+                                    +-----------------+
 765 *|       BAR5      |                                    |       BAR5      |
 766 *+-----------------+                                    +-----------------+
 767 *  EP CONTROLLER 1                                        EP CONTROLLER 2
 768 *
 769 * Set BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
 770 * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
 771 * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
 772 * This function can get the exact BAR used for peer scratchpad from
 773 * epf_ntb_bar[BAR_PEER_SPAD].
 774 *
 775 * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
 776 * gets the address of peer scratchpad from
 777 * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
 778 */
 779static int epf_ntb_peer_spad_bar_set(struct epf_ntb *ntb,
 780				     enum pci_epc_interface_type type)
 781{
 782	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 783	struct pci_epf_bar *peer_epf_bar, *epf_bar;
 784	enum pci_barno peer_barno, barno;
 785	u32 peer_spad_offset;
 786	u8 func_no, vfunc_no;
 787	struct pci_epc *epc;
 788	struct device *dev;
 
 789	int ret;
 790
 791	dev = &ntb->epf->dev;
 792
 793	peer_ntb_epc = ntb->epc[!type];
 794	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_CONFIG];
 795	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 796
 797	ntb_epc = ntb->epc[type];
 798	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
 799	epf_bar = &ntb_epc->epf_bar[barno];
 800	func_no = ntb_epc->func_no;
 801	vfunc_no = ntb_epc->vfunc_no;
 802	epc = ntb_epc->epc;
 803
 804	peer_spad_offset = peer_ntb_epc->reg->spad_offset;
 805	epf_bar->phys_addr = peer_epf_bar->phys_addr + peer_spad_offset;
 806	epf_bar->size = peer_ntb_epc->spad_size;
 807	epf_bar->barno = barno;
 808	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
 809
 810	ret = pci_epc_set_bar(epc, func_no, vfunc_no, epf_bar);
 811	if (ret) {
 812		dev_err(dev, "%s intf: peer SPAD BAR set failed\n",
 813			pci_epc_interface_string(type));
 814		return ret;
 815	}
 816
 817	return 0;
 818}
 819
 820/**
 821 * epf_ntb_config_sspad_bar_clear() - Clear Config + Self scratchpad BAR
 822 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
 823 *	     address.
 824 *
 825 * +-----------------+------->+------------------+        +-----------------+
 826 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 827 * +-----------------+----+   +------------------+<-------+-----------------+
 828 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 829 * +-----------------+    +-->+------------------+<-------+-----------------+
 830 * |       BAR2      |            Local Memory            |       BAR2      |
 831 * +-----------------+                                    +-----------------+
 832 * |       BAR3      |                                    |       BAR3      |
 833 * +-----------------+                                    +-----------------+
 834 * |       BAR4      |                                    |       BAR4      |
 835 * +-----------------+                                    +-----------------+
 836 * |       BAR5      |                                    |       BAR5      |
 837 * +-----------------+                                    +-----------------+
 838 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 839 *
 840 * Clear BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
 841 * self scratchpad region (removes inbound ATU configuration). While BAR0 is
 842 * the default self scratchpad BAR, an NTB could have other BARs for self
 843 * scratchpad (because of reserved BARs). This function can get the exact BAR
 844 * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
 845 *
 846 * Please note the self scratchpad region and config region is combined to
 847 * a single region and mapped using the same BAR. Also note HOST2's peer
 848 * scratchpad is HOST1's self scratchpad.
 849 */
 850static void epf_ntb_config_sspad_bar_clear(struct epf_ntb_epc *ntb_epc)
 851{
 852	struct pci_epf_bar *epf_bar;
 853	enum pci_barno barno;
 854	u8 func_no, vfunc_no;
 855	struct pci_epc *epc;
 
 856
 857	epc = ntb_epc->epc;
 858	func_no = ntb_epc->func_no;
 859	vfunc_no = ntb_epc->vfunc_no;
 860	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
 861	epf_bar = &ntb_epc->epf_bar[barno];
 862	pci_epc_clear_bar(epc, func_no, vfunc_no, epf_bar);
 863}
 864
 865/**
 866 * epf_ntb_config_sspad_bar_set() - Set Config + Self scratchpad BAR
 867 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
 868 *	     address.
 869 *
 870 * +-----------------+------->+------------------+        +-----------------+
 871 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 872 * +-----------------+----+   +------------------+<-------+-----------------+
 873 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 874 * +-----------------+    +-->+------------------+<-------+-----------------+
 875 * |       BAR2      |            Local Memory            |       BAR2      |
 876 * +-----------------+                                    +-----------------+
 877 * |       BAR3      |                                    |       BAR3      |
 878 * +-----------------+                                    +-----------------+
 879 * |       BAR4      |                                    |       BAR4      |
 880 * +-----------------+                                    +-----------------+
 881 * |       BAR5      |                                    |       BAR5      |
 882 * +-----------------+                                    +-----------------+
 883 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 884 *
 885 * Map BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
 886 * self scratchpad region. While BAR0 is the default self scratchpad BAR, an
 887 * NTB could have other BARs for self scratchpad (because of reserved BARs).
 888 * This function can get the exact BAR used for self scratchpad from
 889 * epf_ntb_bar[BAR_CONFIG].
 890 *
 891 * Please note the self scratchpad region and config region is combined to
 892 * a single region and mapped using the same BAR. Also note HOST2's peer
 893 * scratchpad is HOST1's self scratchpad.
 894 */
 895static int epf_ntb_config_sspad_bar_set(struct epf_ntb_epc *ntb_epc)
 896{
 897	struct pci_epf_bar *epf_bar;
 898	enum pci_barno barno;
 899	u8 func_no, vfunc_no;
 900	struct epf_ntb *ntb;
 901	struct pci_epc *epc;
 902	struct device *dev;
 
 903	int ret;
 904
 905	ntb = ntb_epc->epf_ntb;
 906	dev = &ntb->epf->dev;
 907
 908	epc = ntb_epc->epc;
 909	func_no = ntb_epc->func_no;
 910	vfunc_no = ntb_epc->vfunc_no;
 911	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
 912	epf_bar = &ntb_epc->epf_bar[barno];
 913
 914	ret = pci_epc_set_bar(epc, func_no, vfunc_no, epf_bar);
 915	if (ret) {
 916		dev_err(dev, "%s inft: Config/Status/SPAD BAR set failed\n",
 917			pci_epc_interface_string(ntb_epc->type));
 918		return ret;
 919	}
 920
 921	return 0;
 922}
 923
 924/**
 925 * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
 926 *   config + scratchpad region
 927 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 928 *
 929 * +-----------------+------->+------------------+        +-----------------+
 930 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 931 * +-----------------+----+   +------------------+<-------+-----------------+
 932 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 933 * +-----------------+    +-->+------------------+<-------+-----------------+
 934 * |       BAR2      |            Local Memory            |       BAR2      |
 935 * +-----------------+                                    +-----------------+
 936 * |       BAR3      |                                    |       BAR3      |
 937 * +-----------------+                                    +-----------------+
 938 * |       BAR4      |                                    |       BAR4      |
 939 * +-----------------+                                    +-----------------+
 940 * |       BAR5      |                                    |       BAR5      |
 941 * +-----------------+                                    +-----------------+
 942 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 943 *
 944 * Free the Local Memory mentioned in the above diagram. After invoking this
 945 * function, any of config + self scratchpad region of HOST1 or peer scratchpad
 946 * region of HOST2 should not be accessed.
 947 */
 948static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
 949{
 950	enum pci_epc_interface_type type;
 951	struct epf_ntb_epc *ntb_epc;
 952	enum pci_barno barno;
 953	struct pci_epf *epf;
 954
 955	epf = ntb->epf;
 956	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
 957		ntb_epc = ntb->epc[type];
 958		barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
 959		if (ntb_epc->reg)
 960			pci_epf_free_space(epf, ntb_epc->reg, barno, type);
 961	}
 962}
 963
 964/**
 965 * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
 966 *   region
 967 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 968 * @type: PRIMARY interface or SECONDARY interface
 969 *
 970 * +-----------------+------->+------------------+        +-----------------+
 971 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 972 * +-----------------+----+   +------------------+<-------+-----------------+
 973 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 974 * +-----------------+    +-->+------------------+<-------+-----------------+
 975 * |       BAR2      |            Local Memory            |       BAR2      |
 976 * +-----------------+                                    +-----------------+
 977 * |       BAR3      |                                    |       BAR3      |
 978 * +-----------------+                                    +-----------------+
 979 * |       BAR4      |                                    |       BAR4      |
 980 * +-----------------+                                    +-----------------+
 981 * |       BAR5      |                                    |       BAR5      |
 982 * +-----------------+                                    +-----------------+
 983 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 984 *
 985 * Allocate the Local Memory mentioned in the above diagram. The size of
 986 * CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of SCRATCHPAD REGION
 987 * is obtained from "spad-count" configfs entry.
 988 *
 989 * The size of both config region and scratchpad region has to be aligned,
 990 * since the scratchpad region will also be mapped as PEER SCRATCHPAD of
 991 * other host using a separate BAR.
 992 */
 993static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb,
 994					 enum pci_epc_interface_type type)
 995{
 996	const struct pci_epc_features *peer_epc_features, *epc_features;
 997	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 998	size_t msix_table_size, pba_size, align;
 999	enum pci_barno peer_barno, barno;
1000	struct epf_ntb_ctrl *ctrl;
1001	u32 spad_size, ctrl_size;
1002	u64 size, peer_size;
1003	struct pci_epf *epf;
1004	struct device *dev;
1005	bool msix_capable;
1006	u32 spad_count;
1007	void *base;
1008
1009	epf = ntb->epf;
1010	dev = &epf->dev;
1011	ntb_epc = ntb->epc[type];
1012
1013	epc_features = ntb_epc->epc_features;
1014	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
1015	size = epc_features->bar_fixed_size[barno];
1016	align = epc_features->align;
1017
1018	peer_ntb_epc = ntb->epc[!type];
1019	peer_epc_features = peer_ntb_epc->epc_features;
1020	peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
1021	peer_size = peer_epc_features->bar_fixed_size[peer_barno];
1022
1023	/* Check if epc_features is populated incorrectly */
1024	if ((!IS_ALIGNED(size, align)))
1025		return -EINVAL;
1026
1027	spad_count = ntb->spad_count;
1028
1029	ctrl_size = sizeof(struct epf_ntb_ctrl);
1030	spad_size = spad_count * 4;
1031
1032	msix_capable = epc_features->msix_capable;
1033	if (msix_capable) {
1034		msix_table_size = PCI_MSIX_ENTRY_SIZE * ntb->db_count;
1035		ctrl_size = ALIGN(ctrl_size, 8);
1036		ntb_epc->msix_table_offset = ctrl_size;
1037		ntb_epc->msix_bar = barno;
1038		/* Align to QWORD or 8 Bytes */
1039		pba_size = ALIGN(DIV_ROUND_UP(ntb->db_count, 8), 8);
1040		ctrl_size = ctrl_size + msix_table_size + pba_size;
1041	}
1042
1043	if (!align) {
1044		ctrl_size = roundup_pow_of_two(ctrl_size);
1045		spad_size = roundup_pow_of_two(spad_size);
1046	} else {
1047		ctrl_size = ALIGN(ctrl_size, align);
1048		spad_size = ALIGN(spad_size, align);
1049	}
1050
1051	if (peer_size) {
1052		if (peer_size < spad_size)
1053			spad_count = peer_size / 4;
1054		spad_size = peer_size;
1055	}
1056
1057	/*
1058	 * In order to make sure SPAD offset is aligned to its size,
1059	 * expand control region size to the size of SPAD if SPAD size
1060	 * is greater than control region size.
1061	 */
1062	if (spad_size > ctrl_size)
1063		ctrl_size = spad_size;
1064
1065	if (!size)
1066		size = ctrl_size + spad_size;
1067	else if (size < ctrl_size + spad_size)
1068		return -EINVAL;
1069
1070	base = pci_epf_alloc_space(epf, size, barno, align, type);
1071	if (!base) {
1072		dev_err(dev, "%s intf: Config/Status/SPAD alloc region fail\n",
1073			pci_epc_interface_string(type));
1074		return -ENOMEM;
1075	}
1076
1077	ntb_epc->reg = base;
1078
1079	ctrl = ntb_epc->reg;
1080	ctrl->spad_offset = ctrl_size;
1081	ctrl->spad_count = spad_count;
1082	ctrl->num_mws = ntb->num_mws;
1083	ctrl->db_entry_size = align ? align : 4;
1084	ntb_epc->spad_size = spad_size;
1085
1086	return 0;
1087}
1088
1089/**
1090 * epf_ntb_config_spad_bar_alloc_interface() - Allocate memory for config +
1091 *   scratchpad region for each of PRIMARY and SECONDARY interface
1092 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1093 *
1094 * Wrapper for epf_ntb_config_spad_bar_alloc() which allocates memory for
1095 * config + scratchpad region for a specific interface
1096 */
1097static int epf_ntb_config_spad_bar_alloc_interface(struct epf_ntb *ntb)
1098{
1099	enum pci_epc_interface_type type;
1100	struct device *dev;
1101	int ret;
1102
1103	dev = &ntb->epf->dev;
1104
1105	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1106		ret = epf_ntb_config_spad_bar_alloc(ntb, type);
1107		if (ret) {
1108			dev_err(dev, "%s intf: Config/SPAD BAR alloc failed\n",
1109				pci_epc_interface_string(type));
1110			return ret;
1111		}
1112	}
1113
1114	return 0;
1115}
1116
1117/**
1118 * epf_ntb_free_peer_mem() - Free memory allocated in peers outbound address
1119 *   space
1120 * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
1121 *   address regions
1122 *
1123 * +-----------------+    +---->+----------------+-----------+-----------------+
1124 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1125 * +-----------------+    |     +----------------+           +-----------------+
1126 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1127 * +-----------------+----+     +----------------+         | |                 |
1128 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1129 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1130 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1131 * +-----------------+    |     |----------------+     | |   |                 |
1132 * |       BAR4      |    |     |                |     | |   +-----------------+
1133 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1134 * |       BAR5      |    |     |                |   | |     +-----------------+
1135 * +-----------------+    +---->-----------------+   | |     |                 |
1136 *   EP CONTROLLER 1            |                |   | |     +-----------------+
1137 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1138 *                              +----------------+   |       +-----------------+
1139 *                      (A)      EP CONTROLLER 2     |       |                 |
1140 *                                 (OB SPACE)        |       |                 |
1141 *                                                   +------->      MW1        |
1142 *                                                           |                 |
1143 *                                                           |                 |
1144 *                                                   (B)     +-----------------+
1145 *                                                           |                 |
1146 *                                                           |                 |
1147 *                                                           |                 |
1148 *                                                           |                 |
1149 *                                                           |                 |
1150 *                                                           +-----------------+
1151 *                                                           PCI Address Space
1152 *                                                           (Managed by HOST2)
1153 *
1154 * Free memory allocated in EP CONTROLLER 2 (OB SPACE) in the above diagram.
1155 * It'll free Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3,
1156 * MW4).
1157 */
1158static void epf_ntb_free_peer_mem(struct epf_ntb_epc *ntb_epc)
1159{
1160	struct pci_epf_bar *epf_bar;
1161	void __iomem *mw_addr;
1162	phys_addr_t phys_addr;
1163	enum epf_ntb_bar bar;
1164	enum pci_barno barno;
1165	struct pci_epc *epc;
1166	size_t size;
1167
1168	epc = ntb_epc->epc;
1169
1170	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
1171		barno = ntb_epc->epf_ntb_bar[bar];
1172		mw_addr = ntb_epc->mw_addr[barno];
1173		epf_bar = &ntb_epc->epf_bar[barno];
1174		phys_addr = epf_bar->phys_addr;
1175		size = epf_bar->size;
1176		if (mw_addr) {
1177			pci_epc_mem_free_addr(epc, phys_addr, mw_addr, size);
1178			ntb_epc->mw_addr[barno] = NULL;
1179		}
1180	}
1181}
1182
1183/**
1184 * epf_ntb_db_mw_bar_clear() - Clear doorbell and memory BAR
1185 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
1186 *   address
1187 *
1188 * +-----------------+    +---->+----------------+-----------+-----------------+
1189 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1190 * +-----------------+    |     +----------------+           +-----------------+
1191 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1192 * +-----------------+----+     +----------------+         | |                 |
1193 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1194 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1195 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1196 * +-----------------+    |     |----------------+     | |   |                 |
1197 * |       BAR4      |    |     |                |     | |   +-----------------+
1198 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1199 * |       BAR5      |    |     |                |   | |     +-----------------+
1200 * +-----------------+    +---->-----------------+   | |     |                 |
1201 *   EP CONTROLLER 1            |                |   | |     +-----------------+
1202 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1203 *                              +----------------+   |       +-----------------+
1204 *                      (A)      EP CONTROLLER 2     |       |                 |
1205 *                                 (OB SPACE)        |       |                 |
1206 *                                                   +------->      MW1        |
1207 *                                                           |                 |
1208 *                                                           |                 |
1209 *                                                   (B)     +-----------------+
1210 *                                                           |                 |
1211 *                                                           |                 |
1212 *                                                           |                 |
1213 *                                                           |                 |
1214 *                                                           |                 |
1215 *                                                           +-----------------+
1216 *                                                           PCI Address Space
1217 *                                                           (Managed by HOST2)
1218 *
1219 * Clear doorbell and memory BARs (remove inbound ATU configuration). In the above
1220 * diagram it clears BAR2 TO BAR5 of EP CONTROLLER 1 (Doorbell BAR, MW1 BAR, MW2
1221 * BAR, MW3 BAR and MW4 BAR).
1222 */
1223static void epf_ntb_db_mw_bar_clear(struct epf_ntb_epc *ntb_epc)
1224{
1225	struct pci_epf_bar *epf_bar;
1226	enum epf_ntb_bar bar;
1227	enum pci_barno barno;
1228	u8 func_no, vfunc_no;
1229	struct pci_epc *epc;
 
1230
1231	epc = ntb_epc->epc;
1232
1233	func_no = ntb_epc->func_no;
1234	vfunc_no = ntb_epc->vfunc_no;
1235
1236	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
1237		barno = ntb_epc->epf_ntb_bar[bar];
1238		epf_bar = &ntb_epc->epf_bar[barno];
1239		pci_epc_clear_bar(epc, func_no, vfunc_no, epf_bar);
1240	}
1241}
1242
1243/**
1244 * epf_ntb_db_mw_bar_cleanup() - Clear doorbell/memory BAR and free memory
1245 *   allocated in peers outbound address space
1246 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1247 * @type: PRIMARY interface or SECONDARY interface
1248 *
1249 * Wrapper for epf_ntb_db_mw_bar_clear() to clear HOST1's BAR and
1250 * epf_ntb_free_peer_mem() which frees up HOST2 outbound memory.
1251 */
1252static void epf_ntb_db_mw_bar_cleanup(struct epf_ntb *ntb,
1253				      enum pci_epc_interface_type type)
1254{
1255	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
1256
1257	ntb_epc = ntb->epc[type];
1258	peer_ntb_epc = ntb->epc[!type];
1259
1260	epf_ntb_db_mw_bar_clear(ntb_epc);
1261	epf_ntb_free_peer_mem(peer_ntb_epc);
1262}
1263
1264/**
1265 * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capability
1266 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1267 * @type: PRIMARY interface or SECONDARY interface
1268 *
1269 * Configure MSI/MSI-X capability for each interface with number of
1270 * interrupts equal to "db_count" configfs entry.
1271 */
1272static int epf_ntb_configure_interrupt(struct epf_ntb *ntb,
1273				       enum pci_epc_interface_type type)
1274{
1275	const struct pci_epc_features *epc_features;
1276	bool msix_capable, msi_capable;
1277	struct epf_ntb_epc *ntb_epc;
1278	u8 func_no, vfunc_no;
1279	struct pci_epc *epc;
1280	struct device *dev;
1281	u32 db_count;
 
1282	int ret;
1283
1284	ntb_epc = ntb->epc[type];
1285	dev = &ntb->epf->dev;
1286
1287	epc_features = ntb_epc->epc_features;
1288	msix_capable = epc_features->msix_capable;
1289	msi_capable = epc_features->msi_capable;
1290
1291	if (!(msix_capable || msi_capable)) {
1292		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
1293		return -EINVAL;
1294	}
1295
1296	func_no = ntb_epc->func_no;
1297	vfunc_no = ntb_epc->vfunc_no;
1298
1299	db_count = ntb->db_count;
1300	if (db_count > MAX_DB_COUNT) {
1301		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
1302		return -EINVAL;
1303	}
1304
1305	ntb->db_count = db_count;
1306	epc = ntb_epc->epc;
1307
1308	if (msi_capable) {
1309		ret = pci_epc_set_msi(epc, func_no, vfunc_no, db_count);
1310		if (ret) {
1311			dev_err(dev, "%s intf: MSI configuration failed\n",
1312				pci_epc_interface_string(type));
1313			return ret;
1314		}
1315	}
1316
1317	if (msix_capable) {
1318		ret = pci_epc_set_msix(epc, func_no, vfunc_no, db_count,
1319				       ntb_epc->msix_bar,
1320				       ntb_epc->msix_table_offset);
1321		if (ret) {
1322			dev_err(dev, "MSI configuration failed\n");
1323			return ret;
1324		}
1325	}
1326
1327	return 0;
1328}
1329
1330/**
1331 * epf_ntb_alloc_peer_mem() - Allocate memory in peer's outbound address space
1332 * @dev: The PCI device.
1333 * @ntb_epc: EPC associated with one of the HOST whose BAR holds peer's outbound
1334 *   address
1335 * @bar: BAR of @ntb_epc in for which memory has to be allocated (could be
1336 *   BAR_DB_MW1, BAR_MW2, BAR_MW3, BAR_MW4)
1337 * @peer_ntb_epc: EPC associated with HOST whose outbound address space is
1338 *   used by @ntb_epc
1339 * @size: Size of the address region that has to be allocated in peers OB SPACE
1340 *
1341 *
1342 * +-----------------+    +---->+----------------+-----------+-----------------+
1343 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1344 * +-----------------+    |     +----------------+           +-----------------+
1345 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1346 * +-----------------+----+     +----------------+         | |                 |
1347 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1348 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1349 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1350 * +-----------------+    |     |----------------+     | |   |                 |
1351 * |       BAR4      |    |     |                |     | |   +-----------------+
1352 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1353 * |       BAR5      |    |     |                |   | |     +-----------------+
1354 * +-----------------+    +---->-----------------+   | |     |                 |
1355 *   EP CONTROLLER 1            |                |   | |     +-----------------+
1356 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1357 *                              +----------------+   |       +-----------------+
1358 *                      (A)      EP CONTROLLER 2     |       |                 |
1359 *                                 (OB SPACE)        |       |                 |
1360 *                                                   +------->      MW1        |
1361 *                                                           |                 |
1362 *                                                           |                 |
1363 *                                                   (B)     +-----------------+
1364 *                                                           |                 |
1365 *                                                           |                 |
1366 *                                                           |                 |
1367 *                                                           |                 |
1368 *                                                           |                 |
1369 *                                                           +-----------------+
1370 *                                                           PCI Address Space
1371 *                                                           (Managed by HOST2)
1372 *
1373 * Allocate memory in OB space of EP CONTROLLER 2 in the above diagram. Allocate
1374 * for Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3, MW4).
1375 */
1376static int epf_ntb_alloc_peer_mem(struct device *dev,
1377				  struct epf_ntb_epc *ntb_epc,
1378				  enum epf_ntb_bar bar,
1379				  struct epf_ntb_epc *peer_ntb_epc,
1380				  size_t size)
1381{
1382	const struct pci_epc_features *epc_features;
1383	struct pci_epf_bar *epf_bar;
1384	struct pci_epc *peer_epc;
1385	phys_addr_t phys_addr;
1386	void __iomem *mw_addr;
1387	enum pci_barno barno;
1388	size_t align;
1389
1390	epc_features = ntb_epc->epc_features;
1391	align = epc_features->align;
1392
1393	if (size < 128)
1394		size = 128;
1395
1396	if (align)
1397		size = ALIGN(size, align);
1398	else
1399		size = roundup_pow_of_two(size);
1400
1401	peer_epc = peer_ntb_epc->epc;
1402	mw_addr = pci_epc_mem_alloc_addr(peer_epc, &phys_addr, size);
1403	if (!mw_addr) {
1404		dev_err(dev, "%s intf: Failed to allocate OB address\n",
1405			pci_epc_interface_string(peer_ntb_epc->type));
1406		return -ENOMEM;
1407	}
1408
1409	barno = ntb_epc->epf_ntb_bar[bar];
1410	epf_bar = &ntb_epc->epf_bar[barno];
1411	ntb_epc->mw_addr[barno] = mw_addr;
1412
1413	epf_bar->phys_addr = phys_addr;
1414	epf_bar->size = size;
1415	epf_bar->barno = barno;
1416	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
1417
1418	return 0;
1419}
1420
1421/**
1422 * epf_ntb_db_mw_bar_init() - Configure Doorbell and Memory window BARs
1423 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1424 * @type: PRIMARY interface or SECONDARY interface
1425 *
1426 * Wrapper for epf_ntb_alloc_peer_mem() and pci_epc_set_bar() that allocates
1427 * memory in OB address space of HOST2 and configures BAR of HOST1
1428 */
1429static int epf_ntb_db_mw_bar_init(struct epf_ntb *ntb,
1430				  enum pci_epc_interface_type type)
1431{
1432	const struct pci_epc_features *epc_features;
1433	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
1434	struct pci_epf_bar *epf_bar;
1435	struct epf_ntb_ctrl *ctrl;
1436	u32 num_mws, db_count;
1437	enum epf_ntb_bar bar;
1438	enum pci_barno barno;
1439	u8 func_no, vfunc_no;
1440	struct pci_epc *epc;
1441	struct device *dev;
1442	size_t align;
1443	int ret, i;
 
1444	u64 size;
1445
1446	ntb_epc = ntb->epc[type];
1447	peer_ntb_epc = ntb->epc[!type];
1448
1449	dev = &ntb->epf->dev;
1450	epc_features = ntb_epc->epc_features;
1451	align = epc_features->align;
1452	func_no = ntb_epc->func_no;
1453	vfunc_no = ntb_epc->vfunc_no;
1454	epc = ntb_epc->epc;
1455	num_mws = ntb->num_mws;
1456	db_count = ntb->db_count;
1457
1458	for (bar = BAR_DB_MW1, i = 0; i < num_mws; bar++, i++) {
1459		if (bar == BAR_DB_MW1) {
1460			align = align ? align : 4;
1461			size = db_count * align;
1462			size = ALIGN(size, ntb->mws_size[i]);
1463			ctrl = ntb_epc->reg;
1464			ctrl->mw1_offset = size;
1465			size += ntb->mws_size[i];
1466		} else {
1467			size = ntb->mws_size[i];
1468		}
1469
1470		ret = epf_ntb_alloc_peer_mem(dev, ntb_epc, bar,
1471					     peer_ntb_epc, size);
1472		if (ret) {
1473			dev_err(dev, "%s intf: DoorBell mem alloc failed\n",
1474				pci_epc_interface_string(type));
1475			goto err_alloc_peer_mem;
1476		}
1477
1478		barno = ntb_epc->epf_ntb_bar[bar];
1479		epf_bar = &ntb_epc->epf_bar[barno];
1480
1481		ret = pci_epc_set_bar(epc, func_no, vfunc_no, epf_bar);
1482		if (ret) {
1483			dev_err(dev, "%s intf: DoorBell BAR set failed\n",
1484				pci_epc_interface_string(type));
1485			goto err_alloc_peer_mem;
1486		}
1487	}
1488
1489	return 0;
1490
1491err_alloc_peer_mem:
1492	epf_ntb_db_mw_bar_cleanup(ntb, type);
1493
1494	return ret;
1495}
1496
1497/**
1498 * epf_ntb_epc_destroy_interface() - Cleanup NTB EPC interface
1499 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1500 * @type: PRIMARY interface or SECONDARY interface
1501 *
1502 * Unbind NTB function device from EPC and relinquish reference to pci_epc
1503 * for each of the interface.
1504 */
1505static void epf_ntb_epc_destroy_interface(struct epf_ntb *ntb,
1506					  enum pci_epc_interface_type type)
1507{
1508	struct epf_ntb_epc *ntb_epc;
1509	struct pci_epc *epc;
1510	struct pci_epf *epf;
1511
1512	if (type < 0)
1513		return;
1514
1515	epf = ntb->epf;
1516	ntb_epc = ntb->epc[type];
1517	if (!ntb_epc)
1518		return;
1519	epc = ntb_epc->epc;
1520	pci_epc_remove_epf(epc, epf, type);
1521	pci_epc_put(epc);
1522}
1523
1524/**
1525 * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
1526 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1527 *
1528 * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
1529 */
1530static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
1531{
1532	enum pci_epc_interface_type type;
1533
1534	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
1535		epf_ntb_epc_destroy_interface(ntb, type);
1536}
1537
1538/**
1539 * epf_ntb_epc_create_interface() - Create and initialize NTB EPC interface
1540 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1541 * @epc: struct pci_epc to which a particular NTB interface should be associated
1542 * @type: PRIMARY interface or SECONDARY interface
1543 *
1544 * Allocate memory for NTB EPC interface and initialize it.
1545 */
1546static int epf_ntb_epc_create_interface(struct epf_ntb *ntb,
1547					struct pci_epc *epc,
1548					enum pci_epc_interface_type type)
1549{
1550	const struct pci_epc_features *epc_features;
1551	struct pci_epf_bar *epf_bar;
1552	struct epf_ntb_epc *ntb_epc;
1553	u8 func_no, vfunc_no;
1554	struct pci_epf *epf;
1555	struct device *dev;
 
1556
1557	dev = &ntb->epf->dev;
1558
1559	ntb_epc = devm_kzalloc(dev, sizeof(*ntb_epc), GFP_KERNEL);
1560	if (!ntb_epc)
1561		return -ENOMEM;
1562
1563	epf = ntb->epf;
1564	vfunc_no = epf->vfunc_no;
1565	if (type == PRIMARY_INTERFACE) {
1566		func_no = epf->func_no;
1567		epf_bar = epf->bar;
1568	} else {
1569		func_no = epf->sec_epc_func_no;
1570		epf_bar = epf->sec_epc_bar;
1571	}
1572
1573	ntb_epc->linkup = false;
1574	ntb_epc->epc = epc;
1575	ntb_epc->func_no = func_no;
1576	ntb_epc->vfunc_no = vfunc_no;
1577	ntb_epc->type = type;
1578	ntb_epc->epf_bar = epf_bar;
1579	ntb_epc->epf_ntb = ntb;
1580
1581	epc_features = pci_epc_get_features(epc, func_no, vfunc_no);
1582	if (!epc_features)
1583		return -EINVAL;
1584	ntb_epc->epc_features = epc_features;
1585
1586	ntb->epc[type] = ntb_epc;
1587
1588	return 0;
1589}
1590
1591/**
1592 * epf_ntb_epc_create() - Create and initialize NTB EPC interface
1593 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1594 *
1595 * Get a reference to EPC device and bind NTB function device to that EPC
1596 * for each of the interface. It is also a wrapper to
1597 * epf_ntb_epc_create_interface() to allocate memory for NTB EPC interface
1598 * and initialize it
1599 */
1600static int epf_ntb_epc_create(struct epf_ntb *ntb)
1601{
1602	struct pci_epf *epf;
1603	struct device *dev;
1604	int ret;
1605
1606	epf = ntb->epf;
1607	dev = &epf->dev;
1608
1609	ret = epf_ntb_epc_create_interface(ntb, epf->epc, PRIMARY_INTERFACE);
1610	if (ret) {
1611		dev_err(dev, "PRIMARY intf: Fail to create NTB EPC\n");
1612		return ret;
1613	}
1614
1615	ret = epf_ntb_epc_create_interface(ntb, epf->sec_epc,
1616					   SECONDARY_INTERFACE);
1617	if (ret) {
1618		dev_err(dev, "SECONDARY intf: Fail to create NTB EPC\n");
1619		goto err_epc_create;
1620	}
1621
1622	return 0;
1623
1624err_epc_create:
1625	epf_ntb_epc_destroy_interface(ntb, PRIMARY_INTERFACE);
1626
1627	return ret;
1628}
1629
1630/**
1631 * epf_ntb_init_epc_bar_interface() - Identify BARs to be used for each of
1632 *   the NTB constructs (scratchpad region, doorbell, memorywindow)
1633 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1634 * @type: PRIMARY interface or SECONDARY interface
1635 *
1636 * Identify the free BARs to be used for each of BAR_CONFIG, BAR_PEER_SPAD,
1637 * BAR_DB_MW1, BAR_MW2, BAR_MW3 and BAR_MW4.
1638 */
1639static int epf_ntb_init_epc_bar_interface(struct epf_ntb *ntb,
1640					  enum pci_epc_interface_type type)
1641{
1642	const struct pci_epc_features *epc_features;
1643	struct epf_ntb_epc *ntb_epc;
1644	enum pci_barno barno;
1645	enum epf_ntb_bar bar;
1646	struct device *dev;
1647	u32 num_mws;
1648	int i;
1649
1650	barno = BAR_0;
1651	ntb_epc = ntb->epc[type];
1652	num_mws = ntb->num_mws;
1653	dev = &ntb->epf->dev;
1654	epc_features = ntb_epc->epc_features;
1655
1656	/* These are required BARs which are mandatory for NTB functionality */
1657	for (bar = BAR_CONFIG; bar <= BAR_DB_MW1; bar++, barno++) {
1658		barno = pci_epc_get_next_free_bar(epc_features, barno);
1659		if (barno < 0) {
1660			dev_err(dev, "%s intf: Fail to get NTB function BAR\n",
1661				pci_epc_interface_string(type));
1662			return barno;
1663		}
1664		ntb_epc->epf_ntb_bar[bar] = barno;
1665	}
1666
1667	/* These are optional BARs which don't impact NTB functionality */
1668	for (bar = BAR_MW2, i = 1; i < num_mws; bar++, barno++, i++) {
1669		barno = pci_epc_get_next_free_bar(epc_features, barno);
1670		if (barno < 0) {
1671			ntb->num_mws = i;
1672			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
1673		}
1674		ntb_epc->epf_ntb_bar[bar] = barno;
1675	}
1676
1677	return 0;
1678}
1679
1680/**
1681 * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
1682 * constructs (scratchpad region, doorbell, memorywindow)
1683 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1684 *
1685 * Wrapper to epf_ntb_init_epc_bar_interface() to identify the free BARs
1686 * to be used for each of BAR_CONFIG, BAR_PEER_SPAD, BAR_DB_MW1, BAR_MW2,
1687 * BAR_MW3 and BAR_MW4 for all the interfaces.
1688 */
1689static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
1690{
1691	enum pci_epc_interface_type type;
1692	struct device *dev;
1693	int ret;
1694
1695	dev = &ntb->epf->dev;
1696	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1697		ret = epf_ntb_init_epc_bar_interface(ntb, type);
1698		if (ret) {
1699			dev_err(dev, "Fail to init EPC bar for %s interface\n",
1700				pci_epc_interface_string(type));
1701			return ret;
1702		}
1703	}
1704
1705	return 0;
1706}
1707
1708/**
1709 * epf_ntb_epc_init_interface() - Initialize NTB interface
1710 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1711 * @type: PRIMARY interface or SECONDARY interface
1712 *
1713 * Wrapper to initialize a particular EPC interface and start the workqueue
1714 * to check for commands from host. This function will write to the
1715 * EP controller HW for configuring it.
1716 */
1717static int epf_ntb_epc_init_interface(struct epf_ntb *ntb,
1718				      enum pci_epc_interface_type type)
1719{
1720	struct epf_ntb_epc *ntb_epc;
1721	u8 func_no, vfunc_no;
1722	struct pci_epc *epc;
1723	struct pci_epf *epf;
1724	struct device *dev;
 
1725	int ret;
1726
1727	ntb_epc = ntb->epc[type];
1728	epf = ntb->epf;
1729	dev = &epf->dev;
1730	epc = ntb_epc->epc;
1731	func_no = ntb_epc->func_no;
1732	vfunc_no = ntb_epc->vfunc_no;
1733
1734	ret = epf_ntb_config_sspad_bar_set(ntb->epc[type]);
1735	if (ret) {
1736		dev_err(dev, "%s intf: Config/self SPAD BAR init failed\n",
1737			pci_epc_interface_string(type));
1738		return ret;
1739	}
1740
1741	ret = epf_ntb_peer_spad_bar_set(ntb, type);
1742	if (ret) {
1743		dev_err(dev, "%s intf: Peer SPAD BAR init failed\n",
1744			pci_epc_interface_string(type));
1745		goto err_peer_spad_bar_init;
1746	}
1747
1748	ret = epf_ntb_configure_interrupt(ntb, type);
1749	if (ret) {
1750		dev_err(dev, "%s intf: Interrupt configuration failed\n",
1751			pci_epc_interface_string(type));
1752		goto err_peer_spad_bar_init;
1753	}
1754
1755	ret = epf_ntb_db_mw_bar_init(ntb, type);
1756	if (ret) {
1757		dev_err(dev, "%s intf: DB/MW BAR init failed\n",
1758			pci_epc_interface_string(type));
1759		goto err_db_mw_bar_init;
1760	}
1761
1762	if (vfunc_no <= 1) {
1763		ret = pci_epc_write_header(epc, func_no, vfunc_no, epf->header);
1764		if (ret) {
1765			dev_err(dev, "%s intf: Configuration header write failed\n",
1766				pci_epc_interface_string(type));
1767			goto err_write_header;
1768		}
1769	}
1770
1771	INIT_DELAYED_WORK(&ntb->epc[type]->cmd_handler, epf_ntb_cmd_handler);
1772	queue_work(kpcintb_workqueue, &ntb->epc[type]->cmd_handler.work);
1773
1774	return 0;
1775
1776err_write_header:
1777	epf_ntb_db_mw_bar_cleanup(ntb, type);
1778
1779err_db_mw_bar_init:
1780	epf_ntb_peer_spad_bar_clear(ntb->epc[type]);
1781
1782err_peer_spad_bar_init:
1783	epf_ntb_config_sspad_bar_clear(ntb->epc[type]);
1784
1785	return ret;
1786}
1787
1788/**
1789 * epf_ntb_epc_cleanup_interface() - Cleanup NTB interface
1790 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1791 * @type: PRIMARY interface or SECONDARY interface
1792 *
1793 * Wrapper to cleanup a particular NTB interface.
1794 */
1795static void epf_ntb_epc_cleanup_interface(struct epf_ntb *ntb,
1796					  enum pci_epc_interface_type type)
1797{
1798	struct epf_ntb_epc *ntb_epc;
1799
1800	if (type < 0)
1801		return;
1802
1803	ntb_epc = ntb->epc[type];
1804	cancel_delayed_work(&ntb_epc->cmd_handler);
1805	epf_ntb_db_mw_bar_cleanup(ntb, type);
1806	epf_ntb_peer_spad_bar_clear(ntb_epc);
1807	epf_ntb_config_sspad_bar_clear(ntb_epc);
1808}
1809
1810/**
1811 * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
1812 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1813 *
1814 * Wrapper to cleanup all NTB interfaces.
1815 */
1816static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
1817{
1818	enum pci_epc_interface_type type;
1819
1820	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
1821		epf_ntb_epc_cleanup_interface(ntb, type);
1822}
1823
1824/**
1825 * epf_ntb_epc_init() - Initialize all NTB interfaces
1826 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1827 *
1828 * Wrapper to initialize all NTB interface and start the workqueue
1829 * to check for commands from host.
1830 */
1831static int epf_ntb_epc_init(struct epf_ntb *ntb)
1832{
1833	enum pci_epc_interface_type type;
1834	struct device *dev;
1835	int ret;
1836
1837	dev = &ntb->epf->dev;
1838
1839	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1840		ret = epf_ntb_epc_init_interface(ntb, type);
1841		if (ret) {
1842			dev_err(dev, "%s intf: Failed to initialize\n",
1843				pci_epc_interface_string(type));
1844			goto err_init_type;
1845		}
1846	}
1847
1848	return 0;
1849
1850err_init_type:
1851	epf_ntb_epc_cleanup_interface(ntb, type - 1);
1852
1853	return ret;
1854}
1855
1856/**
1857 * epf_ntb_bind() - Initialize endpoint controller to provide NTB functionality
1858 * @epf: NTB endpoint function device
1859 *
1860 * Initialize both the endpoint controllers associated with NTB function device.
1861 * Invoked when a primary interface or secondary interface is bound to EPC
1862 * device. This function will succeed only when EPC is bound to both the
1863 * interfaces.
1864 */
1865static int epf_ntb_bind(struct pci_epf *epf)
1866{
1867	struct epf_ntb *ntb = epf_get_drvdata(epf);
1868	struct device *dev = &epf->dev;
1869	int ret;
1870
1871	if (!epf->epc) {
1872		dev_dbg(dev, "PRIMARY EPC interface not yet bound\n");
1873		return 0;
1874	}
1875
1876	if (!epf->sec_epc) {
1877		dev_dbg(dev, "SECONDARY EPC interface not yet bound\n");
1878		return 0;
1879	}
1880
1881	ret = epf_ntb_epc_create(ntb);
1882	if (ret) {
1883		dev_err(dev, "Failed to create NTB EPC\n");
1884		return ret;
1885	}
1886
1887	ret = epf_ntb_init_epc_bar(ntb);
1888	if (ret) {
1889		dev_err(dev, "Failed to create NTB EPC\n");
1890		goto err_bar_init;
1891	}
1892
1893	ret = epf_ntb_config_spad_bar_alloc_interface(ntb);
1894	if (ret) {
1895		dev_err(dev, "Failed to allocate BAR memory\n");
1896		goto err_bar_alloc;
1897	}
1898
1899	ret = epf_ntb_epc_init(ntb);
1900	if (ret) {
1901		dev_err(dev, "Failed to initialize EPC\n");
1902		goto err_bar_alloc;
1903	}
1904
1905	epf_set_drvdata(epf, ntb);
1906
1907	return 0;
1908
1909err_bar_alloc:
1910	epf_ntb_config_spad_bar_free(ntb);
1911
1912err_bar_init:
1913	epf_ntb_epc_destroy(ntb);
1914
1915	return ret;
1916}
1917
1918/**
1919 * epf_ntb_unbind() - Cleanup the initialization from epf_ntb_bind()
1920 * @epf: NTB endpoint function device
1921 *
1922 * Cleanup the initialization from epf_ntb_bind()
1923 */
1924static void epf_ntb_unbind(struct pci_epf *epf)
1925{
1926	struct epf_ntb *ntb = epf_get_drvdata(epf);
1927
1928	epf_ntb_epc_cleanup(ntb);
1929	epf_ntb_config_spad_bar_free(ntb);
1930	epf_ntb_epc_destroy(ntb);
1931}
1932
1933#define EPF_NTB_R(_name)						\
1934static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
1935				      char *page)			\
1936{									\
1937	struct config_group *group = to_config_group(item);		\
1938	struct epf_ntb *ntb = to_epf_ntb(group);			\
1939									\
1940	return sysfs_emit(page, "%d\n", ntb->_name);			\
1941}
1942
1943#define EPF_NTB_W(_name)						\
1944static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
1945				       const char *page, size_t len)	\
1946{									\
1947	struct config_group *group = to_config_group(item);		\
1948	struct epf_ntb *ntb = to_epf_ntb(group);			\
1949	u32 val;							\
 
1950									\
1951	if (kstrtou32(page, 0, &val) < 0)				\
1952		return -EINVAL;						\
 
1953									\
1954	ntb->_name = val;						\
1955									\
1956	return len;							\
1957}
1958
1959#define EPF_NTB_MW_R(_name)						\
1960static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
1961				      char *page)			\
1962{									\
1963	struct config_group *group = to_config_group(item);		\
1964	struct epf_ntb *ntb = to_epf_ntb(group);			\
1965	int win_no;							\
1966									\
1967	sscanf(#_name, "mw%d", &win_no);				\
1968									\
1969	return sysfs_emit(page, "%lld\n", ntb->mws_size[win_no - 1]);	\
1970}
1971
1972#define EPF_NTB_MW_W(_name)						\
1973static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
1974				       const char *page, size_t len)	\
1975{									\
1976	struct config_group *group = to_config_group(item);		\
1977	struct epf_ntb *ntb = to_epf_ntb(group);			\
1978	struct device *dev = &ntb->epf->dev;				\
1979	int win_no;							\
1980	u64 val;							\
 
1981									\
1982	if (kstrtou64(page, 0, &val) < 0)				\
1983		return -EINVAL;						\
 
1984									\
1985	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
1986		return -EINVAL;						\
1987									\
1988	if (ntb->num_mws < win_no) {					\
1989		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
1990		return -EINVAL;						\
1991	}								\
1992									\
1993	ntb->mws_size[win_no - 1] = val;				\
1994									\
1995	return len;							\
1996}
1997
1998static ssize_t epf_ntb_num_mws_store(struct config_item *item,
1999				     const char *page, size_t len)
2000{
2001	struct config_group *group = to_config_group(item);
2002	struct epf_ntb *ntb = to_epf_ntb(group);
2003	u32 val;
 
2004
2005	if (kstrtou32(page, 0, &val) < 0)
2006		return -EINVAL;
 
2007
2008	if (val > MAX_MW)
2009		return -EINVAL;
2010
2011	ntb->num_mws = val;
2012
2013	return len;
2014}
2015
2016EPF_NTB_R(spad_count)
2017EPF_NTB_W(spad_count)
2018EPF_NTB_R(db_count)
2019EPF_NTB_W(db_count)
2020EPF_NTB_R(num_mws)
2021EPF_NTB_MW_R(mw1)
2022EPF_NTB_MW_W(mw1)
2023EPF_NTB_MW_R(mw2)
2024EPF_NTB_MW_W(mw2)
2025EPF_NTB_MW_R(mw3)
2026EPF_NTB_MW_W(mw3)
2027EPF_NTB_MW_R(mw4)
2028EPF_NTB_MW_W(mw4)
2029
2030CONFIGFS_ATTR(epf_ntb_, spad_count);
2031CONFIGFS_ATTR(epf_ntb_, db_count);
2032CONFIGFS_ATTR(epf_ntb_, num_mws);
2033CONFIGFS_ATTR(epf_ntb_, mw1);
2034CONFIGFS_ATTR(epf_ntb_, mw2);
2035CONFIGFS_ATTR(epf_ntb_, mw3);
2036CONFIGFS_ATTR(epf_ntb_, mw4);
2037
2038static struct configfs_attribute *epf_ntb_attrs[] = {
2039	&epf_ntb_attr_spad_count,
2040	&epf_ntb_attr_db_count,
2041	&epf_ntb_attr_num_mws,
2042	&epf_ntb_attr_mw1,
2043	&epf_ntb_attr_mw2,
2044	&epf_ntb_attr_mw3,
2045	&epf_ntb_attr_mw4,
2046	NULL,
2047};
2048
2049static const struct config_item_type ntb_group_type = {
2050	.ct_attrs	= epf_ntb_attrs,
2051	.ct_owner	= THIS_MODULE,
2052};
2053
2054/**
2055 * epf_ntb_add_cfs() - Add configfs directory specific to NTB
2056 * @epf: NTB endpoint function device
2057 * @group: A pointer to the config_group structure referencing a group of
2058 *	   config_items of a specific type that belong to a specific sub-system.
2059 *
2060 * Add configfs directory specific to NTB. This directory will hold
2061 * NTB specific properties like db_count, spad_count, num_mws etc.,
2062 */
2063static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
2064					    struct config_group *group)
2065{
2066	struct epf_ntb *ntb = epf_get_drvdata(epf);
2067	struct config_group *ntb_group = &ntb->group;
2068	struct device *dev = &epf->dev;
2069
2070	config_group_init_type_name(ntb_group, dev_name(dev), &ntb_group_type);
2071
2072	return ntb_group;
2073}
2074
2075/**
2076 * epf_ntb_probe() - Probe NTB function driver
2077 * @epf: NTB endpoint function device
2078 * @id: NTB endpoint function device ID
2079 *
2080 * Probe NTB function driver when endpoint function bus detects a NTB
2081 * endpoint function.
2082 */
2083static int epf_ntb_probe(struct pci_epf *epf,
2084			 const struct pci_epf_device_id *id)
2085{
2086	struct epf_ntb *ntb;
2087	struct device *dev;
2088
2089	dev = &epf->dev;
2090
2091	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
2092	if (!ntb)
2093		return -ENOMEM;
2094
2095	epf->header = &epf_ntb_header;
2096	ntb->epf = epf;
2097	epf_set_drvdata(epf, ntb);
2098
2099	return 0;
2100}
2101
2102static const struct pci_epf_ops epf_ntb_ops = {
2103	.bind	= epf_ntb_bind,
2104	.unbind	= epf_ntb_unbind,
2105	.add_cfs = epf_ntb_add_cfs,
2106};
2107
2108static const struct pci_epf_device_id epf_ntb_ids[] = {
2109	{
2110		.name = "pci_epf_ntb",
2111	},
2112	{},
2113};
2114
2115static struct pci_epf_driver epf_ntb_driver = {
2116	.driver.name	= "pci_epf_ntb",
2117	.probe		= epf_ntb_probe,
2118	.id_table	= epf_ntb_ids,
2119	.ops		= &epf_ntb_ops,
2120	.owner		= THIS_MODULE,
2121};
2122
2123static int __init epf_ntb_init(void)
2124{
2125	int ret;
2126
2127	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
2128					    WQ_HIGHPRI, 0);
2129	ret = pci_epf_register_driver(&epf_ntb_driver);
2130	if (ret) {
2131		destroy_workqueue(kpcintb_workqueue);
2132		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
2133		return ret;
2134	}
2135
2136	return 0;
2137}
2138module_init(epf_ntb_init);
2139
2140static void __exit epf_ntb_exit(void)
2141{
2142	pci_epf_unregister_driver(&epf_ntb_driver);
2143	destroy_workqueue(kpcintb_workqueue);
2144}
2145module_exit(epf_ntb_exit);
2146
2147MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
2148MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
2149MODULE_LICENSE("GPL v2");
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Endpoint Function Driver to implement Non-Transparent Bridge functionality
   4 *
   5 * Copyright (C) 2020 Texas Instruments
   6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
   7 */
   8
   9/*
  10 * The PCI NTB function driver configures the SoC with multiple PCIe Endpoint
  11 * (EP) controller instances (see diagram below) in such a way that
  12 * transactions from one EP controller are routed to the other EP controller.
  13 * Once PCI NTB function driver configures the SoC with multiple EP instances,
  14 * HOST1 and HOST2 can communicate with each other using SoC as a bridge.
  15 *
  16 *    +-------------+                                   +-------------+
  17 *    |             |                                   |             |
  18 *    |    HOST1    |                                   |    HOST2    |
  19 *    |             |                                   |             |
  20 *    +------^------+                                   +------^------+
  21 *           |                                                 |
  22 *           |                                                 |
  23 * +---------|-------------------------------------------------|---------+
  24 * |  +------v------+                                   +------v------+  |
  25 * |  |             |                                   |             |  |
  26 * |  |     EP      |                                   |     EP      |  |
  27 * |  | CONTROLLER1 |                                   | CONTROLLER2 |  |
  28 * |  |             <----------------------------------->             |  |
  29 * |  |             |                                   |             |  |
  30 * |  |             |                                   |             |  |
  31 * |  |             |  SoC With Multiple EP Instances   |             |  |
  32 * |  |             |  (Configured using NTB Function)  |             |  |
  33 * |  +-------------+                                   +-------------+  |
  34 * +---------------------------------------------------------------------+
  35 */
  36
  37#include <linux/delay.h>
  38#include <linux/io.h>
  39#include <linux/module.h>
  40#include <linux/slab.h>
  41
  42#include <linux/pci-epc.h>
  43#include <linux/pci-epf.h>
  44
  45static struct workqueue_struct *kpcintb_workqueue;
  46
  47#define COMMAND_CONFIGURE_DOORBELL	1
  48#define COMMAND_TEARDOWN_DOORBELL	2
  49#define COMMAND_CONFIGURE_MW		3
  50#define COMMAND_TEARDOWN_MW		4
  51#define COMMAND_LINK_UP			5
  52#define COMMAND_LINK_DOWN		6
  53
  54#define COMMAND_STATUS_OK		1
  55#define COMMAND_STATUS_ERROR		2
  56
  57#define LINK_STATUS_UP			BIT(0)
  58
  59#define SPAD_COUNT			64
  60#define DB_COUNT			4
  61#define NTB_MW_OFFSET			2
  62#define DB_COUNT_MASK			GENMASK(15, 0)
  63#define MSIX_ENABLE			BIT(16)
  64#define MAX_DB_COUNT			32
  65#define MAX_MW				4
  66
  67enum epf_ntb_bar {
  68	BAR_CONFIG,
  69	BAR_PEER_SPAD,
  70	BAR_DB_MW1,
  71	BAR_MW2,
  72	BAR_MW3,
  73	BAR_MW4,
  74};
  75
  76struct epf_ntb {
  77	u32 num_mws;
  78	u32 db_count;
  79	u32 spad_count;
  80	struct pci_epf *epf;
  81	u64 mws_size[MAX_MW];
  82	struct config_group group;
  83	struct epf_ntb_epc *epc[2];
  84};
  85
  86#define to_epf_ntb(epf_group) container_of((epf_group), struct epf_ntb, group)
  87
  88struct epf_ntb_epc {
  89	u8 func_no;
 
  90	bool linkup;
  91	bool is_msix;
  92	int msix_bar;
  93	u32 spad_size;
  94	struct pci_epc *epc;
  95	struct epf_ntb *epf_ntb;
  96	void __iomem *mw_addr[6];
  97	size_t msix_table_offset;
  98	struct epf_ntb_ctrl *reg;
  99	struct pci_epf_bar *epf_bar;
 100	enum pci_barno epf_ntb_bar[6];
 101	struct delayed_work cmd_handler;
 102	enum pci_epc_interface_type type;
 103	const struct pci_epc_features *epc_features;
 104};
 105
 106struct epf_ntb_ctrl {
 107	u32	command;
 108	u32	argument;
 109	u16	command_status;
 110	u16	link_status;
 111	u32	topology;
 112	u64	addr;
 113	u64	size;
 114	u32	num_mws;
 115	u32	mw1_offset;
 116	u32	spad_offset;
 117	u32	spad_count;
 118	u32	db_entry_size;
 119	u32	db_data[MAX_DB_COUNT];
 120	u32	db_offset[MAX_DB_COUNT];
 121} __packed;
 122
 123static struct pci_epf_header epf_ntb_header = {
 124	.vendorid	= PCI_ANY_ID,
 125	.deviceid	= PCI_ANY_ID,
 126	.baseclass_code	= PCI_BASE_CLASS_MEMORY,
 127	.interrupt_pin	= PCI_INTERRUPT_INTA,
 128};
 129
 130/**
 131 * epf_ntb_link_up() - Raise link_up interrupt to both the hosts
 132 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 133 * @link_up: true or false indicating Link is UP or Down
 134 *
 135 * Once NTB function in HOST1 and the NTB function in HOST2 invoke
 136 * ntb_link_enable(), this NTB function driver will trigger a link event to
 137 * the NTB client in both the hosts.
 138 */
 139static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
 140{
 141	enum pci_epc_interface_type type;
 142	enum pci_epc_irq_type irq_type;
 143	struct epf_ntb_epc *ntb_epc;
 144	struct epf_ntb_ctrl *ctrl;
 
 145	struct pci_epc *epc;
 
 146	bool is_msix;
 147	u8 func_no;
 148	int ret;
 149
 150	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
 151		ntb_epc = ntb->epc[type];
 152		epc = ntb_epc->epc;
 153		func_no = ntb_epc->func_no;
 
 154		is_msix = ntb_epc->is_msix;
 155		ctrl = ntb_epc->reg;
 156		if (link_up)
 157			ctrl->link_status |= LINK_STATUS_UP;
 158		else
 159			ctrl->link_status &= ~LINK_STATUS_UP;
 160		irq_type = is_msix ? PCI_EPC_IRQ_MSIX : PCI_EPC_IRQ_MSI;
 161		ret = pci_epc_raise_irq(epc, func_no, irq_type, 1);
 162		if (ret) {
 163			dev_err(&epc->dev,
 164				"%s intf: Failed to raise Link Up IRQ\n",
 165				pci_epc_interface_string(type));
 166			return ret;
 167		}
 168	}
 169
 170	return 0;
 171}
 172
 173/**
 174 * epf_ntb_configure_mw() - Configure the Outbound Address Space for one host
 175 *   to access the memory window of other host
 176 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 177 * @type: PRIMARY interface or SECONDARY interface
 178 * @mw: Index of the memory window (either 0, 1, 2 or 3)
 179 *
 180 * +-----------------+    +---->+----------------+-----------+-----------------+
 181 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
 182 * +-----------------+    |     +----------------+           +-----------------+
 183 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
 184 * +-----------------+----+     +----------------+         | |                 |
 185 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
 186 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
 187 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
 188 * +-----------------+    |     |----------------+     | |   |                 |
 189 * |       BAR4      |    |     |                |     | |   +-----------------+
 190 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
 191 * |       BAR5      |    |     |                |   | |     +-----------------+
 192 * +-----------------+    +---->-----------------+   | |     |                 |
 193 *   EP CONTROLLER 1            |                |   | |     +-----------------+
 194 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
 195 *                              +----------------+   |       +-----------------+
 196 *                      (A)      EP CONTROLLER 2     |       |                 |
 197 *                                 (OB SPACE)        |       |                 |
 198 *                                                   +------->      MW1        |
 199 *                                                           |                 |
 200 *                                                           |                 |
 201 *                                                   (B)     +-----------------+
 202 *                                                           |                 |
 203 *                                                           |                 |
 204 *                                                           |                 |
 205 *                                                           |                 |
 206 *                                                           |                 |
 207 *                                                           +-----------------+
 208 *                                                           PCI Address Space
 209 *                                                           (Managed by HOST2)
 210 *
 211 * This function performs stage (B) in the above diagram (see MW1) i.e., map OB
 212 * address space of memory window to PCI address space.
 213 *
 214 * This operation requires 3 parameters
 215 *  1) Address in the outbound address space
 216 *  2) Address in the PCI Address space
 217 *  3) Size of the address region to be mapped
 218 *
 219 * The address in the outbound address space (for MW1, MW2, MW3 and MW4) is
 220 * stored in epf_bar corresponding to BAR_DB_MW1 for MW1 and BAR_MW2, BAR_MW3
 221 * BAR_MW4 for rest of the BARs of epf_ntb_epc that is connected to HOST1. This
 222 * is populated in epf_ntb_alloc_peer_mem() in this driver.
 223 *
 224 * The address and size of the PCI address region that has to be mapped would
 225 * be provided by HOST2 in ctrl->addr and ctrl->size of epf_ntb_epc that is
 226 * connected to HOST2.
 227 *
 228 * Please note Memory window1 (MW1) and Doorbell registers together will be
 229 * mapped to a single BAR (BAR2) above for 32-bit BARs. The exact BAR that's
 230 * used for Memory window (MW) can be obtained from epf_ntb_bar[BAR_DB_MW1],
 231 * epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2].
 232 */
 233static int epf_ntb_configure_mw(struct epf_ntb *ntb,
 234				enum pci_epc_interface_type type, u32 mw)
 235{
 236	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 237	struct pci_epf_bar *peer_epf_bar;
 238	enum pci_barno peer_barno;
 239	struct epf_ntb_ctrl *ctrl;
 240	phys_addr_t phys_addr;
 
 241	struct pci_epc *epc;
 242	u64 addr, size;
 243	int ret = 0;
 244	u8 func_no;
 245
 246	ntb_epc = ntb->epc[type];
 247	epc = ntb_epc->epc;
 248
 249	peer_ntb_epc = ntb->epc[!type];
 250	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
 251	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 252
 253	phys_addr = peer_epf_bar->phys_addr;
 254	ctrl = ntb_epc->reg;
 255	addr = ctrl->addr;
 256	size = ctrl->size;
 257	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
 258		phys_addr += ctrl->mw1_offset;
 259
 260	if (size > ntb->mws_size[mw]) {
 261		dev_err(&epc->dev,
 262			"%s intf: MW: %d Req Sz:%llxx > Supported Sz:%llx\n",
 263			pci_epc_interface_string(type), mw, size,
 264			ntb->mws_size[mw]);
 265		ret = -EINVAL;
 266		goto err_invalid_size;
 267	}
 268
 269	func_no = ntb_epc->func_no;
 
 270
 271	ret = pci_epc_map_addr(epc, func_no, phys_addr, addr, size);
 272	if (ret)
 273		dev_err(&epc->dev,
 274			"%s intf: Failed to map memory window %d address\n",
 275			pci_epc_interface_string(type), mw);
 276
 277err_invalid_size:
 278
 279	return ret;
 280}
 281
 282/**
 283 * epf_ntb_teardown_mw() - Teardown the configured OB ATU
 284 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 285 * @type: PRIMARY interface or SECONDARY interface
 286 * @mw: Index of the memory window (either 0, 1, 2 or 3)
 287 *
 288 * Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
 289 * pci_epc_unmap_addr()
 290 */
 291static void epf_ntb_teardown_mw(struct epf_ntb *ntb,
 292				enum pci_epc_interface_type type, u32 mw)
 293{
 294	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 295	struct pci_epf_bar *peer_epf_bar;
 296	enum pci_barno peer_barno;
 297	struct epf_ntb_ctrl *ctrl;
 298	phys_addr_t phys_addr;
 
 299	struct pci_epc *epc;
 300	u8 func_no;
 301
 302	ntb_epc = ntb->epc[type];
 303	epc = ntb_epc->epc;
 304
 305	peer_ntb_epc = ntb->epc[!type];
 306	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
 307	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 308
 309	phys_addr = peer_epf_bar->phys_addr;
 310	ctrl = ntb_epc->reg;
 311	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
 312		phys_addr += ctrl->mw1_offset;
 313	func_no = ntb_epc->func_no;
 
 314
 315	pci_epc_unmap_addr(epc, func_no, phys_addr);
 316}
 317
 318/**
 319 * epf_ntb_configure_msi() - Map OB address space to MSI address
 320 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 321 * @type: PRIMARY interface or SECONDARY interface
 322 * @db_count: Number of doorbell interrupts to map
 323 *
 324 *+-----------------+    +----->+----------------+-----------+-----------------+
 325 *|       BAR0      |    |      |   Doorbell 1   +---+------->   MSI ADDRESS   |
 326 *+-----------------+    |      +----------------+   |       +-----------------+
 327 *|       BAR1      |    |      |   Doorbell 2   +---+       |                 |
 328 *+-----------------+----+      +----------------+   |       |                 |
 329 *|       BAR2      |           |   Doorbell 3   +---+       |                 |
 330 *+-----------------+----+      +----------------+   |       |                 |
 331 *|       BAR3      |    |      |   Doorbell 4   +---+       |                 |
 332 *+-----------------+    |      |----------------+           |                 |
 333 *|       BAR4      |    |      |                |           |                 |
 334 *+-----------------+    |      |      MW1       |           |                 |
 335 *|       BAR5      |    |      |                |           |                 |
 336 *+-----------------+    +----->-----------------+           |                 |
 337 *  EP CONTROLLER 1             |                |           |                 |
 338 *                              |                |           |                 |
 339 *                              +----------------+           +-----------------+
 340 *                     (A)       EP CONTROLLER 2             |                 |
 341 *                                 (OB SPACE)                |                 |
 342 *                                                           |      MW1        |
 343 *                                                           |                 |
 344 *                                                           |                 |
 345 *                                                   (B)     +-----------------+
 346 *                                                           |                 |
 347 *                                                           |                 |
 348 *                                                           |                 |
 349 *                                                           |                 |
 350 *                                                           |                 |
 351 *                                                           +-----------------+
 352 *                                                           PCI Address Space
 353 *                                                           (Managed by HOST2)
 354 *
 355 *
 356 * This function performs stage (B) in the above diagram (see Doorbell 1,
 357 * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
 358 * doorbell to MSI address in PCI address space.
 359 *
 360 * This operation requires 3 parameters
 361 *  1) Address reserved for doorbell in the outbound address space
 362 *  2) MSI-X address in the PCIe Address space
 363 *  3) Number of MSI-X interrupts that has to be configured
 364 *
 365 * The address in the outbound address space (for the Doorbell) is stored in
 366 * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
 367 * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
 368 * with address for MW1.
 369 *
 370 * pci_epc_map_msi_irq() takes the MSI address from MSI capability register
 371 * and maps the OB address (obtained in epf_ntb_alloc_peer_mem()) to the MSI
 372 * address.
 373 *
 374 * epf_ntb_configure_msi() also stores the MSI data to raise each interrupt
 375 * in db_data of the peer's control region. This helps the peer to raise
 376 * doorbell of the other host by writing db_data to the BAR corresponding to
 377 * BAR_DB_MW1.
 378 */
 379static int epf_ntb_configure_msi(struct epf_ntb *ntb,
 380				 enum pci_epc_interface_type type, u16 db_count)
 381{
 382	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 383	u32 db_entry_size, db_data, db_offset;
 384	struct pci_epf_bar *peer_epf_bar;
 385	struct epf_ntb_ctrl *peer_ctrl;
 386	enum pci_barno peer_barno;
 387	phys_addr_t phys_addr;
 
 388	struct pci_epc *epc;
 389	u8 func_no;
 390	int ret, i;
 391
 392	ntb_epc = ntb->epc[type];
 393	epc = ntb_epc->epc;
 394
 395	peer_ntb_epc = ntb->epc[!type];
 396	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
 397	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 398	peer_ctrl = peer_ntb_epc->reg;
 399	db_entry_size = peer_ctrl->db_entry_size;
 400
 401	phys_addr = peer_epf_bar->phys_addr;
 402	func_no = ntb_epc->func_no;
 
 403
 404	ret = pci_epc_map_msi_irq(epc, func_no, phys_addr, db_count,
 405				  db_entry_size, &db_data, &db_offset);
 406	if (ret) {
 407		dev_err(&epc->dev, "%s intf: Failed to map MSI IRQ\n",
 408			pci_epc_interface_string(type));
 409		return ret;
 410	}
 411
 412	for (i = 0; i < db_count; i++) {
 413		peer_ctrl->db_data[i] = db_data | i;
 414		peer_ctrl->db_offset[i] = db_offset;
 415	}
 416
 417	return 0;
 418}
 419
 420/**
 421 * epf_ntb_configure_msix() - Map OB address space to MSI-X address
 422 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 423 * @type: PRIMARY interface or SECONDARY interface
 424 * @db_count: Number of doorbell interrupts to map
 425 *
 426 *+-----------------+    +----->+----------------+-----------+-----------------+
 427 *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI-X ADDRESS 1 |
 428 *+-----------------+    |      +----------------+           +-----------------+
 429 *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
 430 *+-----------------+----+      +----------------+         | |                 |
 431 *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
 432 *+-----------------+----+      +----------------+       | +-> MSI-X ADDRESS 2 |
 433 *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
 434 *+-----------------+    |      |----------------+     | |   |                 |
 435 *|       BAR4      |    |      |                |     | |   +-----------------+
 436 *+-----------------+    |      |      MW1       +     | +-->+ MSI-X ADDRESS 3||
 437 *|       BAR5      |    |      |                |     |     +-----------------+
 438 *+-----------------+    +----->-----------------+     |     |                 |
 439 *  EP CONTROLLER 1             |                |     |     +-----------------+
 440 *                              |                |     +---->+ MSI-X ADDRESS 4 |
 441 *                              +----------------+           +-----------------+
 442 *                     (A)       EP CONTROLLER 2             |                 |
 443 *                                 (OB SPACE)                |                 |
 444 *                                                           |      MW1        |
 445 *                                                           |                 |
 446 *                                                           |                 |
 447 *                                                   (B)     +-----------------+
 448 *                                                           |                 |
 449 *                                                           |                 |
 450 *                                                           |                 |
 451 *                                                           |                 |
 452 *                                                           |                 |
 453 *                                                           +-----------------+
 454 *                                                           PCI Address Space
 455 *                                                           (Managed by HOST2)
 456 *
 457 * This function performs stage (B) in the above diagram (see Doorbell 1,
 458 * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
 459 * doorbell to MSI-X address in PCI address space.
 460 *
 461 * This operation requires 3 parameters
 462 *  1) Address reserved for doorbell in the outbound address space
 463 *  2) MSI-X address in the PCIe Address space
 464 *  3) Number of MSI-X interrupts that has to be configured
 465 *
 466 * The address in the outbound address space (for the Doorbell) is stored in
 467 * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
 468 * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
 469 * with address for MW1.
 470 *
 471 * The MSI-X address is in the MSI-X table of EP CONTROLLER 2 and
 472 * the count of doorbell is in ctrl->argument of epf_ntb_epc that is connected
 473 * to HOST2. MSI-X table is stored memory mapped to ntb_epc->msix_bar and the
 474 * offset is in ntb_epc->msix_table_offset. From this epf_ntb_configure_msix()
 475 * gets the MSI-X address and data.
 476 *
 477 * epf_ntb_configure_msix() also stores the MSI-X data to raise each interrupt
 478 * in db_data of the peer's control region. This helps the peer to raise
 479 * doorbell of the other host by writing db_data to the BAR corresponding to
 480 * BAR_DB_MW1.
 481 */
 482static int epf_ntb_configure_msix(struct epf_ntb *ntb,
 483				  enum pci_epc_interface_type type,
 484				  u16 db_count)
 485{
 486	const struct pci_epc_features *epc_features;
 487	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 488	struct pci_epf_bar *peer_epf_bar, *epf_bar;
 489	struct pci_epf_msix_tbl *msix_tbl;
 490	struct epf_ntb_ctrl *peer_ctrl;
 491	u32 db_entry_size, msg_data;
 492	enum pci_barno peer_barno;
 493	phys_addr_t phys_addr;
 
 494	struct pci_epc *epc;
 495	size_t align;
 496	u64 msg_addr;
 497	u8 func_no;
 498	int ret, i;
 499
 500	ntb_epc = ntb->epc[type];
 501	epc = ntb_epc->epc;
 502
 503	epf_bar = &ntb_epc->epf_bar[ntb_epc->msix_bar];
 504	msix_tbl = epf_bar->addr + ntb_epc->msix_table_offset;
 505
 506	peer_ntb_epc = ntb->epc[!type];
 507	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
 508	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 509	phys_addr = peer_epf_bar->phys_addr;
 510	peer_ctrl = peer_ntb_epc->reg;
 511	epc_features = ntb_epc->epc_features;
 512	align = epc_features->align;
 513
 514	func_no = ntb_epc->func_no;
 
 515	db_entry_size = peer_ctrl->db_entry_size;
 516
 517	for (i = 0; i < db_count; i++) {
 518		msg_addr = ALIGN_DOWN(msix_tbl[i].msg_addr, align);
 519		msg_data = msix_tbl[i].msg_data;
 520		ret = pci_epc_map_addr(epc, func_no, phys_addr, msg_addr,
 521				       db_entry_size);
 522		if (ret) {
 523			dev_err(&epc->dev,
 524				"%s intf: Failed to configure MSI-X IRQ\n",
 525				pci_epc_interface_string(type));
 526			return ret;
 527		}
 528		phys_addr = phys_addr + db_entry_size;
 529		peer_ctrl->db_data[i] = msg_data;
 530		peer_ctrl->db_offset[i] = msix_tbl[i].msg_addr & (align - 1);
 531	}
 532	ntb_epc->is_msix = true;
 533
 534	return 0;
 535}
 536
 537/**
 538 * epf_ntb_configure_db() - Configure the Outbound Address Space for one host
 539 *   to ring the doorbell of other host
 540 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 541 * @type: PRIMARY interface or SECONDARY interface
 542 * @db_count: Count of the number of doorbells that has to be configured
 543 * @msix: Indicates whether MSI-X or MSI should be used
 544 *
 545 * Invokes epf_ntb_configure_msix() or epf_ntb_configure_msi() required for
 546 * one HOST to ring the doorbell of other HOST.
 547 */
 548static int epf_ntb_configure_db(struct epf_ntb *ntb,
 549				enum pci_epc_interface_type type,
 550				u16 db_count, bool msix)
 551{
 552	struct epf_ntb_epc *ntb_epc;
 553	struct pci_epc *epc;
 554	int ret;
 555
 556	if (db_count > MAX_DB_COUNT)
 557		return -EINVAL;
 558
 559	ntb_epc = ntb->epc[type];
 560	epc = ntb_epc->epc;
 561
 562	if (msix)
 563		ret = epf_ntb_configure_msix(ntb, type, db_count);
 564	else
 565		ret = epf_ntb_configure_msi(ntb, type, db_count);
 566
 567	if (ret)
 568		dev_err(&epc->dev, "%s intf: Failed to configure DB\n",
 569			pci_epc_interface_string(type));
 570
 571	return ret;
 572}
 573
 574/**
 575 * epf_ntb_teardown_db() - Unmap address in OB address space to MSI/MSI-X
 576 *   address
 577 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 578 * @type: PRIMARY interface or SECONDARY interface
 579 *
 580 * Invoke pci_epc_unmap_addr() to unmap OB address to MSI/MSI-X address.
 581 */
 582static void
 583epf_ntb_teardown_db(struct epf_ntb *ntb, enum pci_epc_interface_type type)
 584{
 585	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 586	struct pci_epf_bar *peer_epf_bar;
 587	enum pci_barno peer_barno;
 588	phys_addr_t phys_addr;
 
 589	struct pci_epc *epc;
 590	u8 func_no;
 591
 592	ntb_epc = ntb->epc[type];
 593	epc = ntb_epc->epc;
 594
 595	peer_ntb_epc = ntb->epc[!type];
 596	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
 597	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 598	phys_addr = peer_epf_bar->phys_addr;
 599	func_no = ntb_epc->func_no;
 
 600
 601	pci_epc_unmap_addr(epc, func_no, phys_addr);
 602}
 603
 604/**
 605 * epf_ntb_cmd_handler() - Handle commands provided by the NTB Host
 606 * @work: work_struct for the two epf_ntb_epc (PRIMARY and SECONDARY)
 607 *
 608 * Workqueue function that gets invoked for the two epf_ntb_epc
 609 * periodically (once every 5ms) to see if it has received any commands
 610 * from NTB host. The host can send commands to configure doorbell or
 611 * configure memory window or to update link status.
 612 */
 613static void epf_ntb_cmd_handler(struct work_struct *work)
 614{
 615	enum pci_epc_interface_type type;
 616	struct epf_ntb_epc *ntb_epc;
 617	struct epf_ntb_ctrl *ctrl;
 618	u32 command, argument;
 619	struct epf_ntb *ntb;
 620	struct device *dev;
 621	u16 db_count;
 622	bool is_msix;
 623	int ret;
 624
 625	ntb_epc = container_of(work, struct epf_ntb_epc, cmd_handler.work);
 626	ctrl = ntb_epc->reg;
 627	command = ctrl->command;
 628	if (!command)
 629		goto reset_handler;
 630	argument = ctrl->argument;
 631
 632	ctrl->command = 0;
 633	ctrl->argument = 0;
 634
 635	ctrl = ntb_epc->reg;
 636	type = ntb_epc->type;
 637	ntb = ntb_epc->epf_ntb;
 638	dev = &ntb->epf->dev;
 639
 640	switch (command) {
 641	case COMMAND_CONFIGURE_DOORBELL:
 642		db_count = argument & DB_COUNT_MASK;
 643		is_msix = argument & MSIX_ENABLE;
 644		ret = epf_ntb_configure_db(ntb, type, db_count, is_msix);
 645		if (ret < 0)
 646			ctrl->command_status = COMMAND_STATUS_ERROR;
 647		else
 648			ctrl->command_status = COMMAND_STATUS_OK;
 649		break;
 650	case COMMAND_TEARDOWN_DOORBELL:
 651		epf_ntb_teardown_db(ntb, type);
 652		ctrl->command_status = COMMAND_STATUS_OK;
 653		break;
 654	case COMMAND_CONFIGURE_MW:
 655		ret = epf_ntb_configure_mw(ntb, type, argument);
 656		if (ret < 0)
 657			ctrl->command_status = COMMAND_STATUS_ERROR;
 658		else
 659			ctrl->command_status = COMMAND_STATUS_OK;
 660		break;
 661	case COMMAND_TEARDOWN_MW:
 662		epf_ntb_teardown_mw(ntb, type, argument);
 663		ctrl->command_status = COMMAND_STATUS_OK;
 664		break;
 665	case COMMAND_LINK_UP:
 666		ntb_epc->linkup = true;
 667		if (ntb->epc[PRIMARY_INTERFACE]->linkup &&
 668		    ntb->epc[SECONDARY_INTERFACE]->linkup) {
 669			ret = epf_ntb_link_up(ntb, true);
 670			if (ret < 0)
 671				ctrl->command_status = COMMAND_STATUS_ERROR;
 672			else
 673				ctrl->command_status = COMMAND_STATUS_OK;
 674			goto reset_handler;
 675		}
 676		ctrl->command_status = COMMAND_STATUS_OK;
 677		break;
 678	case COMMAND_LINK_DOWN:
 679		ntb_epc->linkup = false;
 680		ret = epf_ntb_link_up(ntb, false);
 681		if (ret < 0)
 682			ctrl->command_status = COMMAND_STATUS_ERROR;
 683		else
 684			ctrl->command_status = COMMAND_STATUS_OK;
 685		break;
 686	default:
 687		dev_err(dev, "%s intf UNKNOWN command: %d\n",
 688			pci_epc_interface_string(type), command);
 689		break;
 690	}
 691
 692reset_handler:
 693	queue_delayed_work(kpcintb_workqueue, &ntb_epc->cmd_handler,
 694			   msecs_to_jiffies(5));
 695}
 696
 697/**
 698 * epf_ntb_peer_spad_bar_clear() - Clear Peer Scratchpad BAR
 699 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
 700 *	     address.
 701 *
 702 *+-----------------+------->+------------------+        +-----------------+
 703 *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 704 *+-----------------+----+   +------------------+<-------+-----------------+
 705 *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 706 *+-----------------+    +-->+------------------+<-------+-----------------+
 707 *|       BAR2      |            Local Memory            |       BAR2      |
 708 *+-----------------+                                    +-----------------+
 709 *|       BAR3      |                                    |       BAR3      |
 710 *+-----------------+                                    +-----------------+
 711 *|       BAR4      |                                    |       BAR4      |
 712 *+-----------------+                                    +-----------------+
 713 *|       BAR5      |                                    |       BAR5      |
 714 *+-----------------+                                    +-----------------+
 715 *  EP CONTROLLER 1                                        EP CONTROLLER 2
 716 *
 717 * Clear BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
 718 * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
 719 * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
 720 * This function can get the exact BAR used for peer scratchpad from
 721 * epf_ntb_bar[BAR_PEER_SPAD].
 722 *
 723 * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
 724 * gets the address of peer scratchpad from
 725 * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
 726 */
 727static void epf_ntb_peer_spad_bar_clear(struct epf_ntb_epc *ntb_epc)
 728{
 729	struct pci_epf_bar *epf_bar;
 730	enum pci_barno barno;
 
 731	struct pci_epc *epc;
 732	u8 func_no;
 733
 734	epc = ntb_epc->epc;
 735	func_no = ntb_epc->func_no;
 
 736	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
 737	epf_bar = &ntb_epc->epf_bar[barno];
 738	pci_epc_clear_bar(epc, func_no, epf_bar);
 739}
 740
 741/**
 742 * epf_ntb_peer_spad_bar_set() - Set peer scratchpad BAR
 743 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 744 * @type: PRIMARY interface or SECONDARY interface
 745 *
 746 *+-----------------+------->+------------------+        +-----------------+
 747 *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 748 *+-----------------+----+   +------------------+<-------+-----------------+
 749 *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 750 *+-----------------+    +-->+------------------+<-------+-----------------+
 751 *|       BAR2      |            Local Memory            |       BAR2      |
 752 *+-----------------+                                    +-----------------+
 753 *|       BAR3      |                                    |       BAR3      |
 754 *+-----------------+                                    +-----------------+
 755 *|       BAR4      |                                    |       BAR4      |
 756 *+-----------------+                                    +-----------------+
 757 *|       BAR5      |                                    |       BAR5      |
 758 *+-----------------+                                    +-----------------+
 759 *  EP CONTROLLER 1                                        EP CONTROLLER 2
 760 *
 761 * Set BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
 762 * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
 763 * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
 764 * This function can get the exact BAR used for peer scratchpad from
 765 * epf_ntb_bar[BAR_PEER_SPAD].
 766 *
 767 * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
 768 * gets the address of peer scratchpad from
 769 * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
 770 */
 771static int epf_ntb_peer_spad_bar_set(struct epf_ntb *ntb,
 772				     enum pci_epc_interface_type type)
 773{
 774	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 775	struct pci_epf_bar *peer_epf_bar, *epf_bar;
 776	enum pci_barno peer_barno, barno;
 777	u32 peer_spad_offset;
 
 778	struct pci_epc *epc;
 779	struct device *dev;
 780	u8 func_no;
 781	int ret;
 782
 783	dev = &ntb->epf->dev;
 784
 785	peer_ntb_epc = ntb->epc[!type];
 786	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_CONFIG];
 787	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
 788
 789	ntb_epc = ntb->epc[type];
 790	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
 791	epf_bar = &ntb_epc->epf_bar[barno];
 792	func_no = ntb_epc->func_no;
 
 793	epc = ntb_epc->epc;
 794
 795	peer_spad_offset = peer_ntb_epc->reg->spad_offset;
 796	epf_bar->phys_addr = peer_epf_bar->phys_addr + peer_spad_offset;
 797	epf_bar->size = peer_ntb_epc->spad_size;
 798	epf_bar->barno = barno;
 799	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
 800
 801	ret = pci_epc_set_bar(epc, func_no, epf_bar);
 802	if (ret) {
 803		dev_err(dev, "%s intf: peer SPAD BAR set failed\n",
 804			pci_epc_interface_string(type));
 805		return ret;
 806	}
 807
 808	return 0;
 809}
 810
 811/**
 812 * epf_ntb_config_sspad_bar_clear() - Clear Config + Self scratchpad BAR
 813 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
 814 *	     address.
 815 *
 816 * +-----------------+------->+------------------+        +-----------------+
 817 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 818 * +-----------------+----+   +------------------+<-------+-----------------+
 819 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 820 * +-----------------+    +-->+------------------+<-------+-----------------+
 821 * |       BAR2      |            Local Memory            |       BAR2      |
 822 * +-----------------+                                    +-----------------+
 823 * |       BAR3      |                                    |       BAR3      |
 824 * +-----------------+                                    +-----------------+
 825 * |       BAR4      |                                    |       BAR4      |
 826 * +-----------------+                                    +-----------------+
 827 * |       BAR5      |                                    |       BAR5      |
 828 * +-----------------+                                    +-----------------+
 829 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 830 *
 831 * Clear BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
 832 * self scratchpad region (removes inbound ATU configuration). While BAR0 is
 833 * the default self scratchpad BAR, an NTB could have other BARs for self
 834 * scratchpad (because of reserved BARs). This function can get the exact BAR
 835 * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
 836 *
 837 * Please note the self scratchpad region and config region is combined to
 838 * a single region and mapped using the same BAR. Also note HOST2's peer
 839 * scratchpad is HOST1's self scratchpad.
 840 */
 841static void epf_ntb_config_sspad_bar_clear(struct epf_ntb_epc *ntb_epc)
 842{
 843	struct pci_epf_bar *epf_bar;
 844	enum pci_barno barno;
 
 845	struct pci_epc *epc;
 846	u8 func_no;
 847
 848	epc = ntb_epc->epc;
 849	func_no = ntb_epc->func_no;
 
 850	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
 851	epf_bar = &ntb_epc->epf_bar[barno];
 852	pci_epc_clear_bar(epc, func_no, epf_bar);
 853}
 854
 855/**
 856 * epf_ntb_config_sspad_bar_set() - Set Config + Self scratchpad BAR
 857 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
 858 *	     address.
 859 *
 860 * +-----------------+------->+------------------+        +-----------------+
 861 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 862 * +-----------------+----+   +------------------+<-------+-----------------+
 863 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 864 * +-----------------+    +-->+------------------+<-------+-----------------+
 865 * |       BAR2      |            Local Memory            |       BAR2      |
 866 * +-----------------+                                    +-----------------+
 867 * |       BAR3      |                                    |       BAR3      |
 868 * +-----------------+                                    +-----------------+
 869 * |       BAR4      |                                    |       BAR4      |
 870 * +-----------------+                                    +-----------------+
 871 * |       BAR5      |                                    |       BAR5      |
 872 * +-----------------+                                    +-----------------+
 873 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 874 *
 875 * Map BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
 876 * self scratchpad region. While BAR0 is the default self scratchpad BAR, an
 877 * NTB could have other BARs for self scratchpad (because of reserved BARs).
 878 * This function can get the exact BAR used for self scratchpad from
 879 * epf_ntb_bar[BAR_CONFIG].
 880 *
 881 * Please note the self scratchpad region and config region is combined to
 882 * a single region and mapped using the same BAR. Also note HOST2's peer
 883 * scratchpad is HOST1's self scratchpad.
 884 */
 885static int epf_ntb_config_sspad_bar_set(struct epf_ntb_epc *ntb_epc)
 886{
 887	struct pci_epf_bar *epf_bar;
 888	enum pci_barno barno;
 
 889	struct epf_ntb *ntb;
 890	struct pci_epc *epc;
 891	struct device *dev;
 892	u8 func_no;
 893	int ret;
 894
 895	ntb = ntb_epc->epf_ntb;
 896	dev = &ntb->epf->dev;
 897
 898	epc = ntb_epc->epc;
 899	func_no = ntb_epc->func_no;
 
 900	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
 901	epf_bar = &ntb_epc->epf_bar[barno];
 902
 903	ret = pci_epc_set_bar(epc, func_no, epf_bar);
 904	if (ret) {
 905		dev_err(dev, "%s inft: Config/Status/SPAD BAR set failed\n",
 906			pci_epc_interface_string(ntb_epc->type));
 907		return ret;
 908	}
 909
 910	return 0;
 911}
 912
 913/**
 914 * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
 915 *   config + scratchpad region
 916 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 917 *
 918 * +-----------------+------->+------------------+        +-----------------+
 919 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 920 * +-----------------+----+   +------------------+<-------+-----------------+
 921 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 922 * +-----------------+    +-->+------------------+<-------+-----------------+
 923 * |       BAR2      |            Local Memory            |       BAR2      |
 924 * +-----------------+                                    +-----------------+
 925 * |       BAR3      |                                    |       BAR3      |
 926 * +-----------------+                                    +-----------------+
 927 * |       BAR4      |                                    |       BAR4      |
 928 * +-----------------+                                    +-----------------+
 929 * |       BAR5      |                                    |       BAR5      |
 930 * +-----------------+                                    +-----------------+
 931 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 932 *
 933 * Free the Local Memory mentioned in the above diagram. After invoking this
 934 * function, any of config + self scratchpad region of HOST1 or peer scratchpad
 935 * region of HOST2 should not be accessed.
 936 */
 937static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
 938{
 939	enum pci_epc_interface_type type;
 940	struct epf_ntb_epc *ntb_epc;
 941	enum pci_barno barno;
 942	struct pci_epf *epf;
 943
 944	epf = ntb->epf;
 945	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
 946		ntb_epc = ntb->epc[type];
 947		barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
 948		if (ntb_epc->reg)
 949			pci_epf_free_space(epf, ntb_epc->reg, barno, type);
 950	}
 951}
 952
 953/**
 954 * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
 955 *   region
 956 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
 957 * @type: PRIMARY interface or SECONDARY interface
 958 *
 959 * +-----------------+------->+------------------+        +-----------------+
 960 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
 961 * +-----------------+----+   +------------------+<-------+-----------------+
 962 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
 963 * +-----------------+    +-->+------------------+<-------+-----------------+
 964 * |       BAR2      |            Local Memory            |       BAR2      |
 965 * +-----------------+                                    +-----------------+
 966 * |       BAR3      |                                    |       BAR3      |
 967 * +-----------------+                                    +-----------------+
 968 * |       BAR4      |                                    |       BAR4      |
 969 * +-----------------+                                    +-----------------+
 970 * |       BAR5      |                                    |       BAR5      |
 971 * +-----------------+                                    +-----------------+
 972 *   EP CONTROLLER 1                                        EP CONTROLLER 2
 973 *
 974 * Allocate the Local Memory mentioned in the above diagram. The size of
 975 * CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of SCRATCHPAD REGION
 976 * is obtained from "spad-count" configfs entry.
 977 *
 978 * The size of both config region and scratchpad region has to be aligned,
 979 * since the scratchpad region will also be mapped as PEER SCRATCHPAD of
 980 * other host using a separate BAR.
 981 */
 982static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb,
 983					 enum pci_epc_interface_type type)
 984{
 985	const struct pci_epc_features *peer_epc_features, *epc_features;
 986	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
 987	size_t msix_table_size, pba_size, align;
 988	enum pci_barno peer_barno, barno;
 989	struct epf_ntb_ctrl *ctrl;
 990	u32 spad_size, ctrl_size;
 991	u64 size, peer_size;
 992	struct pci_epf *epf;
 993	struct device *dev;
 994	bool msix_capable;
 995	u32 spad_count;
 996	void *base;
 997
 998	epf = ntb->epf;
 999	dev = &epf->dev;
1000	ntb_epc = ntb->epc[type];
1001
1002	epc_features = ntb_epc->epc_features;
1003	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
1004	size = epc_features->bar_fixed_size[barno];
1005	align = epc_features->align;
1006
1007	peer_ntb_epc = ntb->epc[!type];
1008	peer_epc_features = peer_ntb_epc->epc_features;
1009	peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
1010	peer_size = peer_epc_features->bar_fixed_size[peer_barno];
1011
1012	/* Check if epc_features is populated incorrectly */
1013	if ((!IS_ALIGNED(size, align)))
1014		return -EINVAL;
1015
1016	spad_count = ntb->spad_count;
1017
1018	ctrl_size = sizeof(struct epf_ntb_ctrl);
1019	spad_size = spad_count * 4;
1020
1021	msix_capable = epc_features->msix_capable;
1022	if (msix_capable) {
1023		msix_table_size = PCI_MSIX_ENTRY_SIZE * ntb->db_count;
1024		ctrl_size = ALIGN(ctrl_size, 8);
1025		ntb_epc->msix_table_offset = ctrl_size;
1026		ntb_epc->msix_bar = barno;
1027		/* Align to QWORD or 8 Bytes */
1028		pba_size = ALIGN(DIV_ROUND_UP(ntb->db_count, 8), 8);
1029		ctrl_size = ctrl_size + msix_table_size + pba_size;
1030	}
1031
1032	if (!align) {
1033		ctrl_size = roundup_pow_of_two(ctrl_size);
1034		spad_size = roundup_pow_of_two(spad_size);
1035	} else {
1036		ctrl_size = ALIGN(ctrl_size, align);
1037		spad_size = ALIGN(spad_size, align);
1038	}
1039
1040	if (peer_size) {
1041		if (peer_size < spad_size)
1042			spad_count = peer_size / 4;
1043		spad_size = peer_size;
1044	}
1045
1046	/*
1047	 * In order to make sure SPAD offset is aligned to its size,
1048	 * expand control region size to the size of SPAD if SPAD size
1049	 * is greater than control region size.
1050	 */
1051	if (spad_size > ctrl_size)
1052		ctrl_size = spad_size;
1053
1054	if (!size)
1055		size = ctrl_size + spad_size;
1056	else if (size < ctrl_size + spad_size)
1057		return -EINVAL;
1058
1059	base = pci_epf_alloc_space(epf, size, barno, align, type);
1060	if (!base) {
1061		dev_err(dev, "%s intf: Config/Status/SPAD alloc region fail\n",
1062			pci_epc_interface_string(type));
1063		return -ENOMEM;
1064	}
1065
1066	ntb_epc->reg = base;
1067
1068	ctrl = ntb_epc->reg;
1069	ctrl->spad_offset = ctrl_size;
1070	ctrl->spad_count = spad_count;
1071	ctrl->num_mws = ntb->num_mws;
1072	ctrl->db_entry_size = align ? align : 4;
1073	ntb_epc->spad_size = spad_size;
1074
1075	return 0;
1076}
1077
1078/**
1079 * epf_ntb_config_spad_bar_alloc_interface() - Allocate memory for config +
1080 *   scratchpad region for each of PRIMARY and SECONDARY interface
1081 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1082 *
1083 * Wrapper for epf_ntb_config_spad_bar_alloc() which allocates memory for
1084 * config + scratchpad region for a specific interface
1085 */
1086static int epf_ntb_config_spad_bar_alloc_interface(struct epf_ntb *ntb)
1087{
1088	enum pci_epc_interface_type type;
1089	struct device *dev;
1090	int ret;
1091
1092	dev = &ntb->epf->dev;
1093
1094	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1095		ret = epf_ntb_config_spad_bar_alloc(ntb, type);
1096		if (ret) {
1097			dev_err(dev, "%s intf: Config/SPAD BAR alloc failed\n",
1098				pci_epc_interface_string(type));
1099			return ret;
1100		}
1101	}
1102
1103	return 0;
1104}
1105
1106/**
1107 * epf_ntb_free_peer_mem() - Free memory allocated in peers outbound address
1108 *   space
1109 * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
1110 *   address regions
1111 *
1112 * +-----------------+    +---->+----------------+-----------+-----------------+
1113 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1114 * +-----------------+    |     +----------------+           +-----------------+
1115 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1116 * +-----------------+----+     +----------------+         | |                 |
1117 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1118 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1119 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1120 * +-----------------+    |     |----------------+     | |   |                 |
1121 * |       BAR4      |    |     |                |     | |   +-----------------+
1122 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1123 * |       BAR5      |    |     |                |   | |     +-----------------+
1124 * +-----------------+    +---->-----------------+   | |     |                 |
1125 *   EP CONTROLLER 1            |                |   | |     +-----------------+
1126 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1127 *                              +----------------+   |       +-----------------+
1128 *                      (A)      EP CONTROLLER 2     |       |                 |
1129 *                                 (OB SPACE)        |       |                 |
1130 *                                                   +------->      MW1        |
1131 *                                                           |                 |
1132 *                                                           |                 |
1133 *                                                   (B)     +-----------------+
1134 *                                                           |                 |
1135 *                                                           |                 |
1136 *                                                           |                 |
1137 *                                                           |                 |
1138 *                                                           |                 |
1139 *                                                           +-----------------+
1140 *                                                           PCI Address Space
1141 *                                                           (Managed by HOST2)
1142 *
1143 * Free memory allocated in EP CONTROLLER 2 (OB SPACE) in the above diagram.
1144 * It'll free Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3,
1145 * MW4).
1146 */
1147static void epf_ntb_free_peer_mem(struct epf_ntb_epc *ntb_epc)
1148{
1149	struct pci_epf_bar *epf_bar;
1150	void __iomem *mw_addr;
1151	phys_addr_t phys_addr;
1152	enum epf_ntb_bar bar;
1153	enum pci_barno barno;
1154	struct pci_epc *epc;
1155	size_t size;
1156
1157	epc = ntb_epc->epc;
1158
1159	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
1160		barno = ntb_epc->epf_ntb_bar[bar];
1161		mw_addr = ntb_epc->mw_addr[barno];
1162		epf_bar = &ntb_epc->epf_bar[barno];
1163		phys_addr = epf_bar->phys_addr;
1164		size = epf_bar->size;
1165		if (mw_addr) {
1166			pci_epc_mem_free_addr(epc, phys_addr, mw_addr, size);
1167			ntb_epc->mw_addr[barno] = NULL;
1168		}
1169	}
1170}
1171
1172/**
1173 * epf_ntb_db_mw_bar_clear() - Clear doorbell and memory BAR
1174 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
1175 *   address
1176 *
1177 * +-----------------+    +---->+----------------+-----------+-----------------+
1178 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1179 * +-----------------+    |     +----------------+           +-----------------+
1180 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1181 * +-----------------+----+     +----------------+         | |                 |
1182 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1183 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1184 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1185 * +-----------------+    |     |----------------+     | |   |                 |
1186 * |       BAR4      |    |     |                |     | |   +-----------------+
1187 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1188 * |       BAR5      |    |     |                |   | |     +-----------------+
1189 * +-----------------+    +---->-----------------+   | |     |                 |
1190 *   EP CONTROLLER 1            |                |   | |     +-----------------+
1191 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1192 *                              +----------------+   |       +-----------------+
1193 *                      (A)      EP CONTROLLER 2     |       |                 |
1194 *                                 (OB SPACE)        |       |                 |
1195 *                                                   +------->      MW1        |
1196 *                                                           |                 |
1197 *                                                           |                 |
1198 *                                                   (B)     +-----------------+
1199 *                                                           |                 |
1200 *                                                           |                 |
1201 *                                                           |                 |
1202 *                                                           |                 |
1203 *                                                           |                 |
1204 *                                                           +-----------------+
1205 *                                                           PCI Address Space
1206 *                                                           (Managed by HOST2)
1207 *
1208 * Clear doorbell and memory BARs (remove inbound ATU configuration). In the above
1209 * diagram it clears BAR2 TO BAR5 of EP CONTROLLER 1 (Doorbell BAR, MW1 BAR, MW2
1210 * BAR, MW3 BAR and MW4 BAR).
1211 */
1212static void epf_ntb_db_mw_bar_clear(struct epf_ntb_epc *ntb_epc)
1213{
1214	struct pci_epf_bar *epf_bar;
1215	enum epf_ntb_bar bar;
1216	enum pci_barno barno;
 
1217	struct pci_epc *epc;
1218	u8 func_no;
1219
1220	epc = ntb_epc->epc;
1221
1222	func_no = ntb_epc->func_no;
 
1223
1224	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
1225		barno = ntb_epc->epf_ntb_bar[bar];
1226		epf_bar = &ntb_epc->epf_bar[barno];
1227		pci_epc_clear_bar(epc, func_no, epf_bar);
1228	}
1229}
1230
1231/**
1232 * epf_ntb_db_mw_bar_cleanup() - Clear doorbell/memory BAR and free memory
1233 *   allocated in peers outbound address space
1234 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1235 * @type: PRIMARY interface or SECONDARY interface
1236 *
1237 * Wrapper for epf_ntb_db_mw_bar_clear() to clear HOST1's BAR and
1238 * epf_ntb_free_peer_mem() which frees up HOST2 outbound memory.
1239 */
1240static void epf_ntb_db_mw_bar_cleanup(struct epf_ntb *ntb,
1241				      enum pci_epc_interface_type type)
1242{
1243	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
1244
1245	ntb_epc = ntb->epc[type];
1246	peer_ntb_epc = ntb->epc[!type];
1247
1248	epf_ntb_db_mw_bar_clear(ntb_epc);
1249	epf_ntb_free_peer_mem(peer_ntb_epc);
1250}
1251
1252/**
1253 * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capaiblity
1254 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1255 * @type: PRIMARY interface or SECONDARY interface
1256 *
1257 * Configure MSI/MSI-X capability for each interface with number of
1258 * interrupts equal to "db_count" configfs entry.
1259 */
1260static int epf_ntb_configure_interrupt(struct epf_ntb *ntb,
1261				       enum pci_epc_interface_type type)
1262{
1263	const struct pci_epc_features *epc_features;
1264	bool msix_capable, msi_capable;
1265	struct epf_ntb_epc *ntb_epc;
 
1266	struct pci_epc *epc;
1267	struct device *dev;
1268	u32 db_count;
1269	u8 func_no;
1270	int ret;
1271
1272	ntb_epc = ntb->epc[type];
1273	dev = &ntb->epf->dev;
1274
1275	epc_features = ntb_epc->epc_features;
1276	msix_capable = epc_features->msix_capable;
1277	msi_capable = epc_features->msi_capable;
1278
1279	if (!(msix_capable || msi_capable)) {
1280		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
1281		return -EINVAL;
1282	}
1283
1284	func_no = ntb_epc->func_no;
 
1285
1286	db_count = ntb->db_count;
1287	if (db_count > MAX_DB_COUNT) {
1288		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
1289		return -EINVAL;
1290	}
1291
1292	ntb->db_count = db_count;
1293	epc = ntb_epc->epc;
1294
1295	if (msi_capable) {
1296		ret = pci_epc_set_msi(epc, func_no, db_count);
1297		if (ret) {
1298			dev_err(dev, "%s intf: MSI configuration failed\n",
1299				pci_epc_interface_string(type));
1300			return ret;
1301		}
1302	}
1303
1304	if (msix_capable) {
1305		ret = pci_epc_set_msix(epc, func_no, db_count,
1306				       ntb_epc->msix_bar,
1307				       ntb_epc->msix_table_offset);
1308		if (ret) {
1309			dev_err(dev, "MSI configuration failed\n");
1310			return ret;
1311		}
1312	}
1313
1314	return 0;
1315}
1316
1317/**
1318 * epf_ntb_alloc_peer_mem() - Allocate memory in peer's outbound address space
1319 * @dev: The PCI device.
1320 * @ntb_epc: EPC associated with one of the HOST whose BAR holds peer's outbound
1321 *   address
1322 * @bar: BAR of @ntb_epc in for which memory has to be allocated (could be
1323 *   BAR_DB_MW1, BAR_MW2, BAR_MW3, BAR_MW4)
1324 * @peer_ntb_epc: EPC associated with HOST whose outbound address space is
1325 *   used by @ntb_epc
1326 * @size: Size of the address region that has to be allocated in peers OB SPACE
1327 *
1328 *
1329 * +-----------------+    +---->+----------------+-----------+-----------------+
1330 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1331 * +-----------------+    |     +----------------+           +-----------------+
1332 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1333 * +-----------------+----+     +----------------+         | |                 |
1334 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1335 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1336 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1337 * +-----------------+    |     |----------------+     | |   |                 |
1338 * |       BAR4      |    |     |                |     | |   +-----------------+
1339 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1340 * |       BAR5      |    |     |                |   | |     +-----------------+
1341 * +-----------------+    +---->-----------------+   | |     |                 |
1342 *   EP CONTROLLER 1            |                |   | |     +-----------------+
1343 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1344 *                              +----------------+   |       +-----------------+
1345 *                      (A)      EP CONTROLLER 2     |       |                 |
1346 *                                 (OB SPACE)        |       |                 |
1347 *                                                   +------->      MW1        |
1348 *                                                           |                 |
1349 *                                                           |                 |
1350 *                                                   (B)     +-----------------+
1351 *                                                           |                 |
1352 *                                                           |                 |
1353 *                                                           |                 |
1354 *                                                           |                 |
1355 *                                                           |                 |
1356 *                                                           +-----------------+
1357 *                                                           PCI Address Space
1358 *                                                           (Managed by HOST2)
1359 *
1360 * Allocate memory in OB space of EP CONTROLLER 2 in the above diagram. Allocate
1361 * for Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3, MW4).
1362 */
1363static int epf_ntb_alloc_peer_mem(struct device *dev,
1364				  struct epf_ntb_epc *ntb_epc,
1365				  enum epf_ntb_bar bar,
1366				  struct epf_ntb_epc *peer_ntb_epc,
1367				  size_t size)
1368{
1369	const struct pci_epc_features *epc_features;
1370	struct pci_epf_bar *epf_bar;
1371	struct pci_epc *peer_epc;
1372	phys_addr_t phys_addr;
1373	void __iomem *mw_addr;
1374	enum pci_barno barno;
1375	size_t align;
1376
1377	epc_features = ntb_epc->epc_features;
1378	align = epc_features->align;
1379
1380	if (size < 128)
1381		size = 128;
1382
1383	if (align)
1384		size = ALIGN(size, align);
1385	else
1386		size = roundup_pow_of_two(size);
1387
1388	peer_epc = peer_ntb_epc->epc;
1389	mw_addr = pci_epc_mem_alloc_addr(peer_epc, &phys_addr, size);
1390	if (!mw_addr) {
1391		dev_err(dev, "%s intf: Failed to allocate OB address\n",
1392			pci_epc_interface_string(peer_ntb_epc->type));
1393		return -ENOMEM;
1394	}
1395
1396	barno = ntb_epc->epf_ntb_bar[bar];
1397	epf_bar = &ntb_epc->epf_bar[barno];
1398	ntb_epc->mw_addr[barno] = mw_addr;
1399
1400	epf_bar->phys_addr = phys_addr;
1401	epf_bar->size = size;
1402	epf_bar->barno = barno;
1403	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
1404
1405	return 0;
1406}
1407
1408/**
1409 * epf_ntb_db_mw_bar_init() - Configure Doorbell and Memory window BARs
1410 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1411 * @type: PRIMARY interface or SECONDARY interface
1412 *
1413 * Wrapper for epf_ntb_alloc_peer_mem() and pci_epc_set_bar() that allocates
1414 * memory in OB address space of HOST2 and configures BAR of HOST1
1415 */
1416static int epf_ntb_db_mw_bar_init(struct epf_ntb *ntb,
1417				  enum pci_epc_interface_type type)
1418{
1419	const struct pci_epc_features *epc_features;
1420	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
1421	struct pci_epf_bar *epf_bar;
1422	struct epf_ntb_ctrl *ctrl;
1423	u32 num_mws, db_count;
1424	enum epf_ntb_bar bar;
1425	enum pci_barno barno;
 
1426	struct pci_epc *epc;
1427	struct device *dev;
1428	size_t align;
1429	int ret, i;
1430	u8 func_no;
1431	u64 size;
1432
1433	ntb_epc = ntb->epc[type];
1434	peer_ntb_epc = ntb->epc[!type];
1435
1436	dev = &ntb->epf->dev;
1437	epc_features = ntb_epc->epc_features;
1438	align = epc_features->align;
1439	func_no = ntb_epc->func_no;
 
1440	epc = ntb_epc->epc;
1441	num_mws = ntb->num_mws;
1442	db_count = ntb->db_count;
1443
1444	for (bar = BAR_DB_MW1, i = 0; i < num_mws; bar++, i++) {
1445		if (bar == BAR_DB_MW1) {
1446			align = align ? align : 4;
1447			size = db_count * align;
1448			size = ALIGN(size, ntb->mws_size[i]);
1449			ctrl = ntb_epc->reg;
1450			ctrl->mw1_offset = size;
1451			size += ntb->mws_size[i];
1452		} else {
1453			size = ntb->mws_size[i];
1454		}
1455
1456		ret = epf_ntb_alloc_peer_mem(dev, ntb_epc, bar,
1457					     peer_ntb_epc, size);
1458		if (ret) {
1459			dev_err(dev, "%s intf: DoorBell mem alloc failed\n",
1460				pci_epc_interface_string(type));
1461			goto err_alloc_peer_mem;
1462		}
1463
1464		barno = ntb_epc->epf_ntb_bar[bar];
1465		epf_bar = &ntb_epc->epf_bar[barno];
1466
1467		ret = pci_epc_set_bar(epc, func_no, epf_bar);
1468		if (ret) {
1469			dev_err(dev, "%s intf: DoorBell BAR set failed\n",
1470				pci_epc_interface_string(type));
1471			goto err_alloc_peer_mem;
1472		}
1473	}
1474
1475	return 0;
1476
1477err_alloc_peer_mem:
1478	epf_ntb_db_mw_bar_cleanup(ntb, type);
1479
1480	return ret;
1481}
1482
1483/**
1484 * epf_ntb_epc_destroy_interface() - Cleanup NTB EPC interface
1485 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1486 * @type: PRIMARY interface or SECONDARY interface
1487 *
1488 * Unbind NTB function device from EPC and relinquish reference to pci_epc
1489 * for each of the interface.
1490 */
1491static void epf_ntb_epc_destroy_interface(struct epf_ntb *ntb,
1492					  enum pci_epc_interface_type type)
1493{
1494	struct epf_ntb_epc *ntb_epc;
1495	struct pci_epc *epc;
1496	struct pci_epf *epf;
1497
1498	if (type < 0)
1499		return;
1500
1501	epf = ntb->epf;
1502	ntb_epc = ntb->epc[type];
1503	if (!ntb_epc)
1504		return;
1505	epc = ntb_epc->epc;
1506	pci_epc_remove_epf(epc, epf, type);
1507	pci_epc_put(epc);
1508}
1509
1510/**
1511 * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
1512 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1513 *
1514 * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
1515 */
1516static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
1517{
1518	enum pci_epc_interface_type type;
1519
1520	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
1521		epf_ntb_epc_destroy_interface(ntb, type);
1522}
1523
1524/**
1525 * epf_ntb_epc_create_interface() - Create and initialize NTB EPC interface
1526 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1527 * @epc: struct pci_epc to which a particular NTB interface should be associated
1528 * @type: PRIMARY interface or SECONDARY interface
1529 *
1530 * Allocate memory for NTB EPC interface and initialize it.
1531 */
1532static int epf_ntb_epc_create_interface(struct epf_ntb *ntb,
1533					struct pci_epc *epc,
1534					enum pci_epc_interface_type type)
1535{
1536	const struct pci_epc_features *epc_features;
1537	struct pci_epf_bar *epf_bar;
1538	struct epf_ntb_epc *ntb_epc;
 
1539	struct pci_epf *epf;
1540	struct device *dev;
1541	u8 func_no;
1542
1543	dev = &ntb->epf->dev;
1544
1545	ntb_epc = devm_kzalloc(dev, sizeof(*ntb_epc), GFP_KERNEL);
1546	if (!ntb_epc)
1547		return -ENOMEM;
1548
1549	epf = ntb->epf;
 
1550	if (type == PRIMARY_INTERFACE) {
1551		func_no = epf->func_no;
1552		epf_bar = epf->bar;
1553	} else {
1554		func_no = epf->sec_epc_func_no;
1555		epf_bar = epf->sec_epc_bar;
1556	}
1557
1558	ntb_epc->linkup = false;
1559	ntb_epc->epc = epc;
1560	ntb_epc->func_no = func_no;
 
1561	ntb_epc->type = type;
1562	ntb_epc->epf_bar = epf_bar;
1563	ntb_epc->epf_ntb = ntb;
1564
1565	epc_features = pci_epc_get_features(epc, func_no);
1566	if (!epc_features)
1567		return -EINVAL;
1568	ntb_epc->epc_features = epc_features;
1569
1570	ntb->epc[type] = ntb_epc;
1571
1572	return 0;
1573}
1574
1575/**
1576 * epf_ntb_epc_create() - Create and initialize NTB EPC interface
1577 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1578 *
1579 * Get a reference to EPC device and bind NTB function device to that EPC
1580 * for each of the interface. It is also a wrapper to
1581 * epf_ntb_epc_create_interface() to allocate memory for NTB EPC interface
1582 * and initialize it
1583 */
1584static int epf_ntb_epc_create(struct epf_ntb *ntb)
1585{
1586	struct pci_epf *epf;
1587	struct device *dev;
1588	int ret;
1589
1590	epf = ntb->epf;
1591	dev = &epf->dev;
1592
1593	ret = epf_ntb_epc_create_interface(ntb, epf->epc, PRIMARY_INTERFACE);
1594	if (ret) {
1595		dev_err(dev, "PRIMARY intf: Fail to create NTB EPC\n");
1596		return ret;
1597	}
1598
1599	ret = epf_ntb_epc_create_interface(ntb, epf->sec_epc,
1600					   SECONDARY_INTERFACE);
1601	if (ret) {
1602		dev_err(dev, "SECONDARY intf: Fail to create NTB EPC\n");
1603		goto err_epc_create;
1604	}
1605
1606	return 0;
1607
1608err_epc_create:
1609	epf_ntb_epc_destroy_interface(ntb, PRIMARY_INTERFACE);
1610
1611	return ret;
1612}
1613
1614/**
1615 * epf_ntb_init_epc_bar_interface() - Identify BARs to be used for each of
1616 *   the NTB constructs (scratchpad region, doorbell, memorywindow)
1617 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1618 * @type: PRIMARY interface or SECONDARY interface
1619 *
1620 * Identify the free BARs to be used for each of BAR_CONFIG, BAR_PEER_SPAD,
1621 * BAR_DB_MW1, BAR_MW2, BAR_MW3 and BAR_MW4.
1622 */
1623static int epf_ntb_init_epc_bar_interface(struct epf_ntb *ntb,
1624					  enum pci_epc_interface_type type)
1625{
1626	const struct pci_epc_features *epc_features;
1627	struct epf_ntb_epc *ntb_epc;
1628	enum pci_barno barno;
1629	enum epf_ntb_bar bar;
1630	struct device *dev;
1631	u32 num_mws;
1632	int i;
1633
1634	barno = BAR_0;
1635	ntb_epc = ntb->epc[type];
1636	num_mws = ntb->num_mws;
1637	dev = &ntb->epf->dev;
1638	epc_features = ntb_epc->epc_features;
1639
1640	/* These are required BARs which are mandatory for NTB functionality */
1641	for (bar = BAR_CONFIG; bar <= BAR_DB_MW1; bar++, barno++) {
1642		barno = pci_epc_get_next_free_bar(epc_features, barno);
1643		if (barno < 0) {
1644			dev_err(dev, "%s intf: Fail to get NTB function BAR\n",
1645				pci_epc_interface_string(type));
1646			return barno;
1647		}
1648		ntb_epc->epf_ntb_bar[bar] = barno;
1649	}
1650
1651	/* These are optional BARs which don't impact NTB functionality */
1652	for (bar = BAR_MW2, i = 1; i < num_mws; bar++, barno++, i++) {
1653		barno = pci_epc_get_next_free_bar(epc_features, barno);
1654		if (barno < 0) {
1655			ntb->num_mws = i;
1656			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
1657		}
1658		ntb_epc->epf_ntb_bar[bar] = barno;
1659	}
1660
1661	return 0;
1662}
1663
1664/**
1665 * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
1666 * constructs (scratchpad region, doorbell, memorywindow)
1667 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1668 *
1669 * Wrapper to epf_ntb_init_epc_bar_interface() to identify the free BARs
1670 * to be used for each of BAR_CONFIG, BAR_PEER_SPAD, BAR_DB_MW1, BAR_MW2,
1671 * BAR_MW3 and BAR_MW4 for all the interfaces.
1672 */
1673static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
1674{
1675	enum pci_epc_interface_type type;
1676	struct device *dev;
1677	int ret;
1678
1679	dev = &ntb->epf->dev;
1680	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1681		ret = epf_ntb_init_epc_bar_interface(ntb, type);
1682		if (ret) {
1683			dev_err(dev, "Fail to init EPC bar for %s interface\n",
1684				pci_epc_interface_string(type));
1685			return ret;
1686		}
1687	}
1688
1689	return 0;
1690}
1691
1692/**
1693 * epf_ntb_epc_init_interface() - Initialize NTB interface
1694 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1695 * @type: PRIMARY interface or SECONDARY interface
1696 *
1697 * Wrapper to initialize a particular EPC interface and start the workqueue
1698 * to check for commands from host. This function will write to the
1699 * EP controller HW for configuring it.
1700 */
1701static int epf_ntb_epc_init_interface(struct epf_ntb *ntb,
1702				      enum pci_epc_interface_type type)
1703{
1704	struct epf_ntb_epc *ntb_epc;
 
1705	struct pci_epc *epc;
1706	struct pci_epf *epf;
1707	struct device *dev;
1708	u8 func_no;
1709	int ret;
1710
1711	ntb_epc = ntb->epc[type];
1712	epf = ntb->epf;
1713	dev = &epf->dev;
1714	epc = ntb_epc->epc;
1715	func_no = ntb_epc->func_no;
 
1716
1717	ret = epf_ntb_config_sspad_bar_set(ntb->epc[type]);
1718	if (ret) {
1719		dev_err(dev, "%s intf: Config/self SPAD BAR init failed\n",
1720			pci_epc_interface_string(type));
1721		return ret;
1722	}
1723
1724	ret = epf_ntb_peer_spad_bar_set(ntb, type);
1725	if (ret) {
1726		dev_err(dev, "%s intf: Peer SPAD BAR init failed\n",
1727			pci_epc_interface_string(type));
1728		goto err_peer_spad_bar_init;
1729	}
1730
1731	ret = epf_ntb_configure_interrupt(ntb, type);
1732	if (ret) {
1733		dev_err(dev, "%s intf: Interrupt configuration failed\n",
1734			pci_epc_interface_string(type));
1735		goto err_peer_spad_bar_init;
1736	}
1737
1738	ret = epf_ntb_db_mw_bar_init(ntb, type);
1739	if (ret) {
1740		dev_err(dev, "%s intf: DB/MW BAR init failed\n",
1741			pci_epc_interface_string(type));
1742		goto err_db_mw_bar_init;
1743	}
1744
1745	ret = pci_epc_write_header(epc, func_no, epf->header);
1746	if (ret) {
1747		dev_err(dev, "%s intf: Configuration header write failed\n",
1748			pci_epc_interface_string(type));
1749		goto err_write_header;
 
 
1750	}
1751
1752	INIT_DELAYED_WORK(&ntb->epc[type]->cmd_handler, epf_ntb_cmd_handler);
1753	queue_work(kpcintb_workqueue, &ntb->epc[type]->cmd_handler.work);
1754
1755	return 0;
1756
1757err_write_header:
1758	epf_ntb_db_mw_bar_cleanup(ntb, type);
1759
1760err_db_mw_bar_init:
1761	epf_ntb_peer_spad_bar_clear(ntb->epc[type]);
1762
1763err_peer_spad_bar_init:
1764	epf_ntb_config_sspad_bar_clear(ntb->epc[type]);
1765
1766	return ret;
1767}
1768
1769/**
1770 * epf_ntb_epc_cleanup_interface() - Cleanup NTB interface
1771 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1772 * @type: PRIMARY interface or SECONDARY interface
1773 *
1774 * Wrapper to cleanup a particular NTB interface.
1775 */
1776static void epf_ntb_epc_cleanup_interface(struct epf_ntb *ntb,
1777					  enum pci_epc_interface_type type)
1778{
1779	struct epf_ntb_epc *ntb_epc;
1780
1781	if (type < 0)
1782		return;
1783
1784	ntb_epc = ntb->epc[type];
1785	cancel_delayed_work(&ntb_epc->cmd_handler);
1786	epf_ntb_db_mw_bar_cleanup(ntb, type);
1787	epf_ntb_peer_spad_bar_clear(ntb_epc);
1788	epf_ntb_config_sspad_bar_clear(ntb_epc);
1789}
1790
1791/**
1792 * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
1793 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1794 *
1795 * Wrapper to cleanup all NTB interfaces.
1796 */
1797static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
1798{
1799	enum pci_epc_interface_type type;
1800
1801	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
1802		epf_ntb_epc_cleanup_interface(ntb, type);
1803}
1804
1805/**
1806 * epf_ntb_epc_init() - Initialize all NTB interfaces
1807 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1808 *
1809 * Wrapper to initialize all NTB interface and start the workqueue
1810 * to check for commands from host.
1811 */
1812static int epf_ntb_epc_init(struct epf_ntb *ntb)
1813{
1814	enum pci_epc_interface_type type;
1815	struct device *dev;
1816	int ret;
1817
1818	dev = &ntb->epf->dev;
1819
1820	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1821		ret = epf_ntb_epc_init_interface(ntb, type);
1822		if (ret) {
1823			dev_err(dev, "%s intf: Failed to initialize\n",
1824				pci_epc_interface_string(type));
1825			goto err_init_type;
1826		}
1827	}
1828
1829	return 0;
1830
1831err_init_type:
1832	epf_ntb_epc_cleanup_interface(ntb, type - 1);
1833
1834	return ret;
1835}
1836
1837/**
1838 * epf_ntb_bind() - Initialize endpoint controller to provide NTB functionality
1839 * @epf: NTB endpoint function device
1840 *
1841 * Initialize both the endpoint controllers associated with NTB function device.
1842 * Invoked when a primary interface or secondary interface is bound to EPC
1843 * device. This function will succeed only when EPC is bound to both the
1844 * interfaces.
1845 */
1846static int epf_ntb_bind(struct pci_epf *epf)
1847{
1848	struct epf_ntb *ntb = epf_get_drvdata(epf);
1849	struct device *dev = &epf->dev;
1850	int ret;
1851
1852	if (!epf->epc) {
1853		dev_dbg(dev, "PRIMARY EPC interface not yet bound\n");
1854		return 0;
1855	}
1856
1857	if (!epf->sec_epc) {
1858		dev_dbg(dev, "SECONDARY EPC interface not yet bound\n");
1859		return 0;
1860	}
1861
1862	ret = epf_ntb_epc_create(ntb);
1863	if (ret) {
1864		dev_err(dev, "Failed to create NTB EPC\n");
1865		return ret;
1866	}
1867
1868	ret = epf_ntb_init_epc_bar(ntb);
1869	if (ret) {
1870		dev_err(dev, "Failed to create NTB EPC\n");
1871		goto err_bar_init;
1872	}
1873
1874	ret = epf_ntb_config_spad_bar_alloc_interface(ntb);
1875	if (ret) {
1876		dev_err(dev, "Failed to allocate BAR memory\n");
1877		goto err_bar_alloc;
1878	}
1879
1880	ret = epf_ntb_epc_init(ntb);
1881	if (ret) {
1882		dev_err(dev, "Failed to initialize EPC\n");
1883		goto err_bar_alloc;
1884	}
1885
1886	epf_set_drvdata(epf, ntb);
1887
1888	return 0;
1889
1890err_bar_alloc:
1891	epf_ntb_config_spad_bar_free(ntb);
1892
1893err_bar_init:
1894	epf_ntb_epc_destroy(ntb);
1895
1896	return ret;
1897}
1898
1899/**
1900 * epf_ntb_unbind() - Cleanup the initialization from epf_ntb_bind()
1901 * @epf: NTB endpoint function device
1902 *
1903 * Cleanup the initialization from epf_ntb_bind()
1904 */
1905static void epf_ntb_unbind(struct pci_epf *epf)
1906{
1907	struct epf_ntb *ntb = epf_get_drvdata(epf);
1908
1909	epf_ntb_epc_cleanup(ntb);
1910	epf_ntb_config_spad_bar_free(ntb);
1911	epf_ntb_epc_destroy(ntb);
1912}
1913
1914#define EPF_NTB_R(_name)						\
1915static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
1916				      char *page)			\
1917{									\
1918	struct config_group *group = to_config_group(item);		\
1919	struct epf_ntb *ntb = to_epf_ntb(group);			\
1920									\
1921	return sprintf(page, "%d\n", ntb->_name);			\
1922}
1923
1924#define EPF_NTB_W(_name)						\
1925static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
1926				       const char *page, size_t len)	\
1927{									\
1928	struct config_group *group = to_config_group(item);		\
1929	struct epf_ntb *ntb = to_epf_ntb(group);			\
1930	u32 val;							\
1931	int ret;							\
1932									\
1933	ret = kstrtou32(page, 0, &val);					\
1934	if (ret)							\
1935		return ret;						\
1936									\
1937	ntb->_name = val;						\
1938									\
1939	return len;							\
1940}
1941
1942#define EPF_NTB_MW_R(_name)						\
1943static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
1944				      char *page)			\
1945{									\
1946	struct config_group *group = to_config_group(item);		\
1947	struct epf_ntb *ntb = to_epf_ntb(group);			\
1948	int win_no;							\
1949									\
1950	sscanf(#_name, "mw%d", &win_no);				\
1951									\
1952	return sprintf(page, "%lld\n", ntb->mws_size[win_no - 1]);	\
1953}
1954
1955#define EPF_NTB_MW_W(_name)						\
1956static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
1957				       const char *page, size_t len)	\
1958{									\
1959	struct config_group *group = to_config_group(item);		\
1960	struct epf_ntb *ntb = to_epf_ntb(group);			\
1961	struct device *dev = &ntb->epf->dev;				\
1962	int win_no;							\
1963	u64 val;							\
1964	int ret;							\
1965									\
1966	ret = kstrtou64(page, 0, &val);					\
1967	if (ret)							\
1968		return ret;						\
1969									\
1970	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
1971		return -EINVAL;						\
1972									\
1973	if (ntb->num_mws < win_no) {					\
1974		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
1975		return -EINVAL;						\
1976	}								\
1977									\
1978	ntb->mws_size[win_no - 1] = val;				\
1979									\
1980	return len;							\
1981}
1982
1983static ssize_t epf_ntb_num_mws_store(struct config_item *item,
1984				     const char *page, size_t len)
1985{
1986	struct config_group *group = to_config_group(item);
1987	struct epf_ntb *ntb = to_epf_ntb(group);
1988	u32 val;
1989	int ret;
1990
1991	ret = kstrtou32(page, 0, &val);
1992	if (ret)
1993		return ret;
1994
1995	if (val > MAX_MW)
1996		return -EINVAL;
1997
1998	ntb->num_mws = val;
1999
2000	return len;
2001}
2002
2003EPF_NTB_R(spad_count)
2004EPF_NTB_W(spad_count)
2005EPF_NTB_R(db_count)
2006EPF_NTB_W(db_count)
2007EPF_NTB_R(num_mws)
2008EPF_NTB_MW_R(mw1)
2009EPF_NTB_MW_W(mw1)
2010EPF_NTB_MW_R(mw2)
2011EPF_NTB_MW_W(mw2)
2012EPF_NTB_MW_R(mw3)
2013EPF_NTB_MW_W(mw3)
2014EPF_NTB_MW_R(mw4)
2015EPF_NTB_MW_W(mw4)
2016
2017CONFIGFS_ATTR(epf_ntb_, spad_count);
2018CONFIGFS_ATTR(epf_ntb_, db_count);
2019CONFIGFS_ATTR(epf_ntb_, num_mws);
2020CONFIGFS_ATTR(epf_ntb_, mw1);
2021CONFIGFS_ATTR(epf_ntb_, mw2);
2022CONFIGFS_ATTR(epf_ntb_, mw3);
2023CONFIGFS_ATTR(epf_ntb_, mw4);
2024
2025static struct configfs_attribute *epf_ntb_attrs[] = {
2026	&epf_ntb_attr_spad_count,
2027	&epf_ntb_attr_db_count,
2028	&epf_ntb_attr_num_mws,
2029	&epf_ntb_attr_mw1,
2030	&epf_ntb_attr_mw2,
2031	&epf_ntb_attr_mw3,
2032	&epf_ntb_attr_mw4,
2033	NULL,
2034};
2035
2036static const struct config_item_type ntb_group_type = {
2037	.ct_attrs	= epf_ntb_attrs,
2038	.ct_owner	= THIS_MODULE,
2039};
2040
2041/**
2042 * epf_ntb_add_cfs() - Add configfs directory specific to NTB
2043 * @epf: NTB endpoint function device
2044 * @group: A pointer to the config_group structure referencing a group of
2045 *	   config_items of a specific type that belong to a specific sub-system.
2046 *
2047 * Add configfs directory specific to NTB. This directory will hold
2048 * NTB specific properties like db_count, spad_count, num_mws etc.,
2049 */
2050static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
2051					    struct config_group *group)
2052{
2053	struct epf_ntb *ntb = epf_get_drvdata(epf);
2054	struct config_group *ntb_group = &ntb->group;
2055	struct device *dev = &epf->dev;
2056
2057	config_group_init_type_name(ntb_group, dev_name(dev), &ntb_group_type);
2058
2059	return ntb_group;
2060}
2061
2062/**
2063 * epf_ntb_probe() - Probe NTB function driver
2064 * @epf: NTB endpoint function device
 
2065 *
2066 * Probe NTB function driver when endpoint function bus detects a NTB
2067 * endpoint function.
2068 */
2069static int epf_ntb_probe(struct pci_epf *epf)
 
2070{
2071	struct epf_ntb *ntb;
2072	struct device *dev;
2073
2074	dev = &epf->dev;
2075
2076	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
2077	if (!ntb)
2078		return -ENOMEM;
2079
2080	epf->header = &epf_ntb_header;
2081	ntb->epf = epf;
2082	epf_set_drvdata(epf, ntb);
2083
2084	return 0;
2085}
2086
2087static struct pci_epf_ops epf_ntb_ops = {
2088	.bind	= epf_ntb_bind,
2089	.unbind	= epf_ntb_unbind,
2090	.add_cfs = epf_ntb_add_cfs,
2091};
2092
2093static const struct pci_epf_device_id epf_ntb_ids[] = {
2094	{
2095		.name = "pci_epf_ntb",
2096	},
2097	{},
2098};
2099
2100static struct pci_epf_driver epf_ntb_driver = {
2101	.driver.name	= "pci_epf_ntb",
2102	.probe		= epf_ntb_probe,
2103	.id_table	= epf_ntb_ids,
2104	.ops		= &epf_ntb_ops,
2105	.owner		= THIS_MODULE,
2106};
2107
2108static int __init epf_ntb_init(void)
2109{
2110	int ret;
2111
2112	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
2113					    WQ_HIGHPRI, 0);
2114	ret = pci_epf_register_driver(&epf_ntb_driver);
2115	if (ret) {
2116		destroy_workqueue(kpcintb_workqueue);
2117		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
2118		return ret;
2119	}
2120
2121	return 0;
2122}
2123module_init(epf_ntb_init);
2124
2125static void __exit epf_ntb_exit(void)
2126{
2127	pci_epf_unregister_driver(&epf_ntb_driver);
2128	destroy_workqueue(kpcintb_workqueue);
2129}
2130module_exit(epf_ntb_exit);
2131
2132MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
2133MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
2134MODULE_LICENSE("GPL v2");