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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Volume Management Device driver
   4 * Copyright (c) 2015, Intel Corporation.
   5 */
   6
   7#include <linux/device.h>
   8#include <linux/interrupt.h>
   9#include <linux/irq.h>
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/msi.h>
  13#include <linux/pci.h>
  14#include <linux/pci-acpi.h>
  15#include <linux/pci-ecam.h>
  16#include <linux/srcu.h>
  17#include <linux/rculist.h>
  18#include <linux/rcupdate.h>
  19
  20#include <asm/irqdomain.h>
  21
  22#define VMD_CFGBAR	0
  23#define VMD_MEMBAR1	2
  24#define VMD_MEMBAR2	4
  25
  26#define PCI_REG_VMCAP		0x40
  27#define BUS_RESTRICT_CAP(vmcap)	(vmcap & 0x1)
  28#define PCI_REG_VMCONFIG	0x44
  29#define BUS_RESTRICT_CFG(vmcfg)	((vmcfg >> 8) & 0x3)
  30#define VMCONFIG_MSI_REMAP	0x2
  31#define PCI_REG_VMLOCK		0x70
  32#define MB2_SHADOW_EN(vmlock)	(vmlock & 0x2)
  33
  34#define MB2_SHADOW_OFFSET	0x2000
  35#define MB2_SHADOW_SIZE		16
  36
  37enum vmd_features {
  38	/*
  39	 * Device may contain registers which hint the physical location of the
  40	 * membars, in order to allow proper address translation during
  41	 * resource assignment to enable guest virtualization
  42	 */
  43	VMD_FEAT_HAS_MEMBAR_SHADOW		= (1 << 0),
  44
  45	/*
  46	 * Device may provide root port configuration information which limits
  47	 * bus numbering
  48	 */
  49	VMD_FEAT_HAS_BUS_RESTRICTIONS		= (1 << 1),
  50
  51	/*
  52	 * Device contains physical location shadow registers in
  53	 * vendor-specific capability space
  54	 */
  55	VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP	= (1 << 2),
  56
  57	/*
  58	 * Device may use MSI-X vector 0 for software triggering and will not
  59	 * be used for MSI remapping
  60	 */
  61	VMD_FEAT_OFFSET_FIRST_VECTOR		= (1 << 3),
  62
  63	/*
  64	 * Device can bypass remapping MSI-X transactions into its MSI-X table,
  65	 * avoiding the requirement of a VMD MSI domain for child device
  66	 * interrupt handling.
  67	 */
  68	VMD_FEAT_CAN_BYPASS_MSI_REMAP		= (1 << 4),
  69
  70	/*
  71	 * Enable ASPM on the PCIE root ports and set the default LTR of the
  72	 * storage devices on platforms where these values are not configured by
  73	 * BIOS. This is needed for laptops, which require these settings for
  74	 * proper power management of the SoC.
  75	 */
  76	VMD_FEAT_BIOS_PM_QUIRK		= (1 << 5),
  77};
  78
  79#define VMD_BIOS_PM_QUIRK_LTR	0x1003	/* 3145728 ns */
  80
  81#define VMD_FEATS_CLIENT	(VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |	\
  82				 VMD_FEAT_HAS_BUS_RESTRICTIONS |	\
  83				 VMD_FEAT_OFFSET_FIRST_VECTOR |		\
  84				 VMD_FEAT_BIOS_PM_QUIRK)
  85
  86static DEFINE_IDA(vmd_instance_ida);
  87
  88/*
  89 * Lock for manipulating VMD IRQ lists.
  90 */
  91static DEFINE_RAW_SPINLOCK(list_lock);
  92
  93/**
  94 * struct vmd_irq - private data to map driver IRQ to the VMD shared vector
  95 * @node:	list item for parent traversal.
  96 * @irq:	back pointer to parent.
  97 * @enabled:	true if driver enabled IRQ
  98 * @virq:	the virtual IRQ value provided to the requesting driver.
  99 *
 100 * Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to
 101 * a VMD IRQ using this structure.
 102 */
 103struct vmd_irq {
 104	struct list_head	node;
 105	struct vmd_irq_list	*irq;
 106	bool			enabled;
 107	unsigned int		virq;
 108};
 109
 110/**
 111 * struct vmd_irq_list - list of driver requested IRQs mapping to a VMD vector
 112 * @irq_list:	the list of irq's the VMD one demuxes to.
 113 * @srcu:	SRCU struct for local synchronization.
 114 * @count:	number of child IRQs assigned to this vector; used to track
 115 *		sharing.
 116 * @virq:	The underlying VMD Linux interrupt number
 117 */
 118struct vmd_irq_list {
 119	struct list_head	irq_list;
 120	struct srcu_struct	srcu;
 121	unsigned int		count;
 122	unsigned int		virq;
 123};
 124
 125struct vmd_dev {
 126	struct pci_dev		*dev;
 127
 128	spinlock_t		cfg_lock;
 129	void __iomem		*cfgbar;
 130
 131	int msix_count;
 132	struct vmd_irq_list	*irqs;
 133
 134	struct pci_sysdata	sysdata;
 135	struct resource		resources[3];
 136	struct irq_domain	*irq_domain;
 137	struct pci_bus		*bus;
 138	u8			busn_start;
 139	u8			first_vec;
 140	char			*name;
 141	int			instance;
 142};
 143
 144static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
 145{
 146	return container_of(bus->sysdata, struct vmd_dev, sysdata);
 147}
 148
 149static inline unsigned int index_from_irqs(struct vmd_dev *vmd,
 150					   struct vmd_irq_list *irqs)
 151{
 152	return irqs - vmd->irqs;
 153}
 154
 155/*
 156 * Drivers managing a device in a VMD domain allocate their own IRQs as before,
 157 * but the MSI entry for the hardware it's driving will be programmed with a
 158 * destination ID for the VMD MSI-X table.  The VMD muxes interrupts in its
 159 * domain into one of its own, and the VMD driver de-muxes these for the
 160 * handlers sharing that VMD IRQ.  The vmd irq_domain provides the operations
 161 * and irq_chip to set this up.
 162 */
 163static void vmd_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 164{
 165	struct vmd_irq *vmdirq = data->chip_data;
 166	struct vmd_irq_list *irq = vmdirq->irq;
 167	struct vmd_dev *vmd = irq_data_get_irq_handler_data(data);
 168
 169	memset(msg, 0, sizeof(*msg));
 170	msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
 171	msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
 172	msg->arch_addr_lo.destid_0_7 = index_from_irqs(vmd, irq);
 173}
 174
 175/*
 176 * We rely on MSI_FLAG_USE_DEF_CHIP_OPS to set the IRQ mask/unmask ops.
 177 */
 178static void vmd_irq_enable(struct irq_data *data)
 179{
 180	struct vmd_irq *vmdirq = data->chip_data;
 181	unsigned long flags;
 182
 183	raw_spin_lock_irqsave(&list_lock, flags);
 184	WARN_ON(vmdirq->enabled);
 185	list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
 186	vmdirq->enabled = true;
 187	raw_spin_unlock_irqrestore(&list_lock, flags);
 188
 189	data->chip->irq_unmask(data);
 190}
 191
 192static void vmd_irq_disable(struct irq_data *data)
 193{
 194	struct vmd_irq *vmdirq = data->chip_data;
 195	unsigned long flags;
 196
 197	data->chip->irq_mask(data);
 198
 199	raw_spin_lock_irqsave(&list_lock, flags);
 200	if (vmdirq->enabled) {
 201		list_del_rcu(&vmdirq->node);
 202		vmdirq->enabled = false;
 203	}
 204	raw_spin_unlock_irqrestore(&list_lock, flags);
 205}
 206
 207/*
 208 * XXX: Stubbed until we develop acceptable way to not create conflicts with
 209 * other devices sharing the same vector.
 210 */
 211static int vmd_irq_set_affinity(struct irq_data *data,
 212				const struct cpumask *dest, bool force)
 213{
 214	return -EINVAL;
 215}
 216
 217static struct irq_chip vmd_msi_controller = {
 218	.name			= "VMD-MSI",
 219	.irq_enable		= vmd_irq_enable,
 220	.irq_disable		= vmd_irq_disable,
 221	.irq_compose_msi_msg	= vmd_compose_msi_msg,
 222	.irq_set_affinity	= vmd_irq_set_affinity,
 223};
 224
 225static irq_hw_number_t vmd_get_hwirq(struct msi_domain_info *info,
 226				     msi_alloc_info_t *arg)
 227{
 228	return 0;
 229}
 230
 231/*
 232 * XXX: We can be even smarter selecting the best IRQ once we solve the
 233 * affinity problem.
 234 */
 235static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *desc)
 236{
 237	unsigned long flags;
 238	int i, best;
 239
 240	if (vmd->msix_count == 1 + vmd->first_vec)
 241		return &vmd->irqs[vmd->first_vec];
 242
 243	/*
 244	 * White list for fast-interrupt handlers. All others will share the
 245	 * "slow" interrupt vector.
 246	 */
 247	switch (msi_desc_to_pci_dev(desc)->class) {
 248	case PCI_CLASS_STORAGE_EXPRESS:
 249		break;
 250	default:
 251		return &vmd->irqs[vmd->first_vec];
 252	}
 253
 254	raw_spin_lock_irqsave(&list_lock, flags);
 255	best = vmd->first_vec + 1;
 256	for (i = best; i < vmd->msix_count; i++)
 257		if (vmd->irqs[i].count < vmd->irqs[best].count)
 258			best = i;
 259	vmd->irqs[best].count++;
 260	raw_spin_unlock_irqrestore(&list_lock, flags);
 261
 262	return &vmd->irqs[best];
 263}
 264
 265static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info,
 266			unsigned int virq, irq_hw_number_t hwirq,
 267			msi_alloc_info_t *arg)
 268{
 269	struct msi_desc *desc = arg->desc;
 270	struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus);
 271	struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);
 272
 273	if (!vmdirq)
 274		return -ENOMEM;
 275
 276	INIT_LIST_HEAD(&vmdirq->node);
 277	vmdirq->irq = vmd_next_irq(vmd, desc);
 278	vmdirq->virq = virq;
 279
 280	irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, vmdirq,
 281			    handle_untracked_irq, vmd, NULL);
 282	return 0;
 283}
 284
 285static void vmd_msi_free(struct irq_domain *domain,
 286			struct msi_domain_info *info, unsigned int virq)
 287{
 288	struct vmd_irq *vmdirq = irq_get_chip_data(virq);
 289	unsigned long flags;
 290
 291	synchronize_srcu(&vmdirq->irq->srcu);
 292
 293	/* XXX: Potential optimization to rebalance */
 294	raw_spin_lock_irqsave(&list_lock, flags);
 295	vmdirq->irq->count--;
 296	raw_spin_unlock_irqrestore(&list_lock, flags);
 297
 298	kfree(vmdirq);
 299}
 300
 301static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
 302			   int nvec, msi_alloc_info_t *arg)
 303{
 304	struct pci_dev *pdev = to_pci_dev(dev);
 305	struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
 306
 307	if (nvec > vmd->msix_count)
 308		return vmd->msix_count;
 309
 310	memset(arg, 0, sizeof(*arg));
 311	return 0;
 312}
 313
 314static void vmd_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
 315{
 316	arg->desc = desc;
 317}
 318
 319static struct msi_domain_ops vmd_msi_domain_ops = {
 320	.get_hwirq	= vmd_get_hwirq,
 321	.msi_init	= vmd_msi_init,
 322	.msi_free	= vmd_msi_free,
 323	.msi_prepare	= vmd_msi_prepare,
 324	.set_desc	= vmd_set_desc,
 325};
 326
 327static struct msi_domain_info vmd_msi_domain_info = {
 328	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
 329			  MSI_FLAG_PCI_MSIX,
 330	.ops		= &vmd_msi_domain_ops,
 331	.chip		= &vmd_msi_controller,
 332};
 333
 334static void vmd_set_msi_remapping(struct vmd_dev *vmd, bool enable)
 335{
 336	u16 reg;
 337
 338	pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
 339	reg = enable ? (reg & ~VMCONFIG_MSI_REMAP) :
 340		       (reg | VMCONFIG_MSI_REMAP);
 341	pci_write_config_word(vmd->dev, PCI_REG_VMCONFIG, reg);
 342}
 343
 344static int vmd_create_irq_domain(struct vmd_dev *vmd)
 345{
 346	struct fwnode_handle *fn;
 347
 348	fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
 349	if (!fn)
 350		return -ENODEV;
 351
 352	vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info, NULL);
 353	if (!vmd->irq_domain) {
 354		irq_domain_free_fwnode(fn);
 355		return -ENODEV;
 356	}
 357
 358	return 0;
 359}
 360
 361static void vmd_remove_irq_domain(struct vmd_dev *vmd)
 362{
 363	/*
 364	 * Some production BIOS won't enable remapping between soft reboots.
 365	 * Ensure remapping is restored before unloading the driver.
 366	 */
 367	if (!vmd->msix_count)
 368		vmd_set_msi_remapping(vmd, true);
 369
 370	if (vmd->irq_domain) {
 371		struct fwnode_handle *fn = vmd->irq_domain->fwnode;
 372
 373		irq_domain_remove(vmd->irq_domain);
 374		irq_domain_free_fwnode(fn);
 375	}
 376}
 377
 378static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
 379				  unsigned int devfn, int reg, int len)
 380{
 381	unsigned int busnr_ecam = bus->number - vmd->busn_start;
 382	u32 offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
 383
 384	if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
 385		return NULL;
 386
 387	return vmd->cfgbar + offset;
 388}
 389
 390/*
 391 * CPU may deadlock if config space is not serialized on some versions of this
 392 * hardware, so all config space access is done under a spinlock.
 393 */
 394static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
 395			int len, u32 *value)
 396{
 397	struct vmd_dev *vmd = vmd_from_bus(bus);
 398	void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
 399	unsigned long flags;
 400	int ret = 0;
 401
 402	if (!addr)
 403		return -EFAULT;
 404
 405	spin_lock_irqsave(&vmd->cfg_lock, flags);
 406	switch (len) {
 407	case 1:
 408		*value = readb(addr);
 409		break;
 410	case 2:
 411		*value = readw(addr);
 412		break;
 413	case 4:
 414		*value = readl(addr);
 415		break;
 416	default:
 417		ret = -EINVAL;
 418		break;
 419	}
 420	spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 421	return ret;
 422}
 423
 424/*
 425 * VMD h/w converts non-posted config writes to posted memory writes. The
 426 * read-back in this function forces the completion so it returns only after
 427 * the config space was written, as expected.
 428 */
 429static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
 430			 int len, u32 value)
 431{
 432	struct vmd_dev *vmd = vmd_from_bus(bus);
 433	void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
 434	unsigned long flags;
 435	int ret = 0;
 436
 437	if (!addr)
 438		return -EFAULT;
 439
 440	spin_lock_irqsave(&vmd->cfg_lock, flags);
 441	switch (len) {
 442	case 1:
 443		writeb(value, addr);
 444		readb(addr);
 445		break;
 446	case 2:
 447		writew(value, addr);
 448		readw(addr);
 449		break;
 450	case 4:
 451		writel(value, addr);
 452		readl(addr);
 453		break;
 454	default:
 455		ret = -EINVAL;
 456		break;
 457	}
 458	spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 459	return ret;
 460}
 461
 462static struct pci_ops vmd_ops = {
 463	.read		= vmd_pci_read,
 464	.write		= vmd_pci_write,
 465};
 466
 467#ifdef CONFIG_ACPI
 468static struct acpi_device *vmd_acpi_find_companion(struct pci_dev *pci_dev)
 469{
 470	struct pci_host_bridge *bridge;
 471	u32 busnr, addr;
 472
 473	if (pci_dev->bus->ops != &vmd_ops)
 474		return NULL;
 475
 476	bridge = pci_find_host_bridge(pci_dev->bus);
 477	busnr = pci_dev->bus->number - bridge->bus->number;
 478	/*
 479	 * The address computation below is only applicable to relative bus
 480	 * numbers below 32.
 481	 */
 482	if (busnr > 31)
 483		return NULL;
 484
 485	addr = (busnr << 24) | ((u32)pci_dev->devfn << 16) | 0x8000FFFFU;
 486
 487	dev_dbg(&pci_dev->dev, "Looking for ACPI companion (address 0x%x)\n",
 488		addr);
 489
 490	return acpi_find_child_device(ACPI_COMPANION(bridge->dev.parent), addr,
 491				      false);
 492}
 493
 494static bool hook_installed;
 495
 496static void vmd_acpi_begin(void)
 497{
 498	if (pci_acpi_set_companion_lookup_hook(vmd_acpi_find_companion))
 499		return;
 500
 501	hook_installed = true;
 502}
 503
 504static void vmd_acpi_end(void)
 505{
 506	if (!hook_installed)
 507		return;
 508
 509	pci_acpi_clear_companion_lookup_hook();
 510	hook_installed = false;
 511}
 512#else
 513static inline void vmd_acpi_begin(void) { }
 514static inline void vmd_acpi_end(void) { }
 515#endif /* CONFIG_ACPI */
 516
 517static void vmd_domain_reset(struct vmd_dev *vmd)
 518{
 519	u16 bus, max_buses = resource_size(&vmd->resources[0]);
 520	u8 dev, functions, fn, hdr_type;
 521	char __iomem *base;
 522
 523	for (bus = 0; bus < max_buses; bus++) {
 524		for (dev = 0; dev < 32; dev++) {
 525			base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
 526						PCI_DEVFN(dev, 0), 0);
 527
 528			hdr_type = readb(base + PCI_HEADER_TYPE);
 529
 530			functions = (hdr_type & PCI_HEADER_TYPE_MFD) ? 8 : 1;
 531			for (fn = 0; fn < functions; fn++) {
 532				base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
 533						PCI_DEVFN(dev, fn), 0);
 534
 535				hdr_type = readb(base + PCI_HEADER_TYPE) &
 536						PCI_HEADER_TYPE_MASK;
 537
 538				if (hdr_type != PCI_HEADER_TYPE_BRIDGE ||
 539				    (readw(base + PCI_CLASS_DEVICE) !=
 540				     PCI_CLASS_BRIDGE_PCI))
 541					continue;
 542
 543				/*
 544				 * Temporarily disable the I/O range before updating
 545				 * PCI_IO_BASE.
 546				 */
 547				writel(0x0000ffff, base + PCI_IO_BASE_UPPER16);
 548				/* Update lower 16 bits of I/O base/limit */
 549				writew(0x00f0, base + PCI_IO_BASE);
 550				/* Update upper 16 bits of I/O base/limit */
 551				writel(0, base + PCI_IO_BASE_UPPER16);
 552
 553				/* MMIO Base/Limit */
 554				writel(0x0000fff0, base + PCI_MEMORY_BASE);
 555
 556				/* Prefetchable MMIO Base/Limit */
 557				writel(0, base + PCI_PREF_LIMIT_UPPER32);
 558				writel(0x0000fff0, base + PCI_PREF_MEMORY_BASE);
 559				writel(0xffffffff, base + PCI_PREF_BASE_UPPER32);
 560			}
 561		}
 562	}
 563}
 564
 565static void vmd_attach_resources(struct vmd_dev *vmd)
 566{
 567	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
 568	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
 569}
 570
 571static void vmd_detach_resources(struct vmd_dev *vmd)
 572{
 573	vmd->dev->resource[VMD_MEMBAR1].child = NULL;
 574	vmd->dev->resource[VMD_MEMBAR2].child = NULL;
 575}
 576
 577/*
 578 * VMD domains start at 0x10000 to not clash with ACPI _SEG domains.
 579 * Per ACPI r6.0, sec 6.5.6,  _SEG returns an integer, of which the lower
 580 * 16 bits are the PCI Segment Group (domain) number.  Other bits are
 581 * currently reserved.
 582 */
 583static int vmd_find_free_domain(void)
 584{
 585	int domain = 0xffff;
 586	struct pci_bus *bus = NULL;
 587
 588	while ((bus = pci_find_next_bus(bus)) != NULL)
 589		domain = max_t(int, domain, pci_domain_nr(bus));
 590	return domain + 1;
 591}
 592
 593static int vmd_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
 594				resource_size_t *offset1,
 595				resource_size_t *offset2)
 596{
 597	struct pci_dev *dev = vmd->dev;
 598	u64 phys1, phys2;
 599
 600	if (native_hint) {
 601		u32 vmlock;
 602		int ret;
 603
 604		ret = pci_read_config_dword(dev, PCI_REG_VMLOCK, &vmlock);
 605		if (ret || PCI_POSSIBLE_ERROR(vmlock))
 606			return -ENODEV;
 607
 608		if (MB2_SHADOW_EN(vmlock)) {
 609			void __iomem *membar2;
 610
 611			membar2 = pci_iomap(dev, VMD_MEMBAR2, 0);
 612			if (!membar2)
 613				return -ENOMEM;
 614			phys1 = readq(membar2 + MB2_SHADOW_OFFSET);
 615			phys2 = readq(membar2 + MB2_SHADOW_OFFSET + 8);
 616			pci_iounmap(dev, membar2);
 617		} else
 618			return 0;
 619	} else {
 620		/* Hypervisor-Emulated Vendor-Specific Capability */
 621		int pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
 622		u32 reg, regu;
 623
 624		pci_read_config_dword(dev, pos + 4, &reg);
 625
 626		/* "SHDW" */
 627		if (pos && reg == 0x53484457) {
 628			pci_read_config_dword(dev, pos + 8, &reg);
 629			pci_read_config_dword(dev, pos + 12, &regu);
 630			phys1 = (u64) regu << 32 | reg;
 631
 632			pci_read_config_dword(dev, pos + 16, &reg);
 633			pci_read_config_dword(dev, pos + 20, &regu);
 634			phys2 = (u64) regu << 32 | reg;
 635		} else
 636			return 0;
 637	}
 638
 639	*offset1 = dev->resource[VMD_MEMBAR1].start -
 640			(phys1 & PCI_BASE_ADDRESS_MEM_MASK);
 641	*offset2 = dev->resource[VMD_MEMBAR2].start -
 642			(phys2 & PCI_BASE_ADDRESS_MEM_MASK);
 643
 644	return 0;
 645}
 646
 647static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 648{
 649	struct pci_dev *dev = vmd->dev;
 650	u16 reg;
 651
 652	pci_read_config_word(dev, PCI_REG_VMCAP, &reg);
 653	if (BUS_RESTRICT_CAP(reg)) {
 654		pci_read_config_word(dev, PCI_REG_VMCONFIG, &reg);
 655
 656		switch (BUS_RESTRICT_CFG(reg)) {
 657		case 0:
 658			vmd->busn_start = 0;
 659			break;
 660		case 1:
 661			vmd->busn_start = 128;
 662			break;
 663		case 2:
 664			vmd->busn_start = 224;
 665			break;
 666		default:
 667			pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
 668				BUS_RESTRICT_CFG(reg));
 669			return -ENODEV;
 670		}
 671	}
 672
 673	return 0;
 674}
 675
 676static irqreturn_t vmd_irq(int irq, void *data)
 677{
 678	struct vmd_irq_list *irqs = data;
 679	struct vmd_irq *vmdirq;
 680	int idx;
 681
 682	idx = srcu_read_lock(&irqs->srcu);
 683	list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
 684		generic_handle_irq(vmdirq->virq);
 685	srcu_read_unlock(&irqs->srcu, idx);
 686
 687	return IRQ_HANDLED;
 688}
 689
 690static int vmd_alloc_irqs(struct vmd_dev *vmd)
 691{
 692	struct pci_dev *dev = vmd->dev;
 693	int i, err;
 694
 695	vmd->msix_count = pci_msix_vec_count(dev);
 696	if (vmd->msix_count < 0)
 697		return -ENODEV;
 698
 699	vmd->msix_count = pci_alloc_irq_vectors(dev, vmd->first_vec + 1,
 700						vmd->msix_count, PCI_IRQ_MSIX);
 701	if (vmd->msix_count < 0)
 702		return vmd->msix_count;
 703
 704	vmd->irqs = devm_kcalloc(&dev->dev, vmd->msix_count, sizeof(*vmd->irqs),
 705				 GFP_KERNEL);
 706	if (!vmd->irqs)
 707		return -ENOMEM;
 708
 709	for (i = 0; i < vmd->msix_count; i++) {
 710		err = init_srcu_struct(&vmd->irqs[i].srcu);
 711		if (err)
 712			return err;
 713
 714		INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
 715		vmd->irqs[i].virq = pci_irq_vector(dev, i);
 716		err = devm_request_irq(&dev->dev, vmd->irqs[i].virq,
 717				       vmd_irq, IRQF_NO_THREAD,
 718				       vmd->name, &vmd->irqs[i]);
 719		if (err)
 720			return err;
 721	}
 722
 723	return 0;
 724}
 725
 726/*
 727 * Since VMD is an aperture to regular PCIe root ports, only allow it to
 728 * control features that the OS is allowed to control on the physical PCI bus.
 729 */
 730static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge,
 731				       struct pci_host_bridge *vmd_bridge)
 732{
 733	vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug;
 734	vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug;
 735	vmd_bridge->native_aer = root_bridge->native_aer;
 736	vmd_bridge->native_pme = root_bridge->native_pme;
 737	vmd_bridge->native_ltr = root_bridge->native_ltr;
 738	vmd_bridge->native_dpc = root_bridge->native_dpc;
 739}
 740
 741/*
 742 * Enable ASPM and LTR settings on devices that aren't configured by BIOS.
 743 */
 744static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
 745{
 746	unsigned long features = *(unsigned long *)userdata;
 747	u16 ltr = VMD_BIOS_PM_QUIRK_LTR;
 748	u32 ltr_reg;
 749	int pos;
 750
 751	if (!(features & VMD_FEAT_BIOS_PM_QUIRK))
 752		return 0;
 753
 754	pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL);
 755
 756	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR);
 757	if (!pos)
 758		return 0;
 759
 760	/*
 761	 * Skip if the max snoop LTR is non-zero, indicating BIOS has set it
 762	 * so the LTR quirk is not needed.
 763	 */
 764	pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, &ltr_reg);
 765	if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK)))
 766		return 0;
 767
 768	/*
 769	 * Set the default values to the maximum required by the platform to
 770	 * allow the deepest power management savings. Write as a DWORD where
 771	 * the lower word is the max snoop latency and the upper word is the
 772	 * max non-snoop latency.
 773	 */
 774	ltr_reg = (ltr << 16) | ltr;
 775	pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg);
 776	pci_info(pdev, "VMD: Default LTR value set by driver\n");
 777
 778	return 0;
 779}
 780
 781static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 782{
 783	struct pci_sysdata *sd = &vmd->sysdata;
 784	struct resource *res;
 785	u32 upper_bits;
 786	unsigned long flags;
 787	LIST_HEAD(resources);
 788	resource_size_t offset[2] = {0};
 789	resource_size_t membar2_offset = 0x2000;
 790	struct pci_bus *child;
 791	struct pci_dev *dev;
 792	int ret;
 793
 794	/*
 795	 * Shadow registers may exist in certain VMD device ids which allow
 796	 * guests to correctly assign host physical addresses to the root ports
 797	 * and child devices. These registers will either return the host value
 798	 * or 0, depending on an enable bit in the VMD device.
 799	 */
 800	if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
 801		membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
 802		ret = vmd_get_phys_offsets(vmd, true, &offset[0], &offset[1]);
 803		if (ret)
 804			return ret;
 805	} else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
 806		ret = vmd_get_phys_offsets(vmd, false, &offset[0], &offset[1]);
 807		if (ret)
 808			return ret;
 809	}
 810
 811	/*
 812	 * Certain VMD devices may have a root port configuration option which
 813	 * limits the bus range to between 0-127, 128-255, or 224-255
 814	 */
 815	if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
 816		ret = vmd_get_bus_number_start(vmd);
 817		if (ret)
 818			return ret;
 819	}
 820
 821	res = &vmd->dev->resource[VMD_CFGBAR];
 822	vmd->resources[0] = (struct resource) {
 823		.name  = "VMD CFGBAR",
 824		.start = vmd->busn_start,
 825		.end   = vmd->busn_start + (resource_size(res) >> 20) - 1,
 826		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
 827	};
 828
 829	/*
 830	 * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
 831	 * put 32-bit resources in the window.
 832	 *
 833	 * There's no hardware reason why a 64-bit window *couldn't*
 834	 * contain a 32-bit resource, but pbus_size_mem() computes the
 835	 * bridge window size assuming a 64-bit window will contain no
 836	 * 32-bit resources.  __pci_assign_resource() enforces that
 837	 * artificial restriction to make sure everything will fit.
 838	 *
 839	 * The only way we could use a 64-bit non-prefetchable MEMBAR is
 840	 * if its address is <4GB so that we can convert it to a 32-bit
 841	 * resource.  To be visible to the host OS, all VMD endpoints must
 842	 * be initially configured by platform BIOS, which includes setting
 843	 * up these resources.  We can assume the device is configured
 844	 * according to the platform needs.
 845	 */
 846	res = &vmd->dev->resource[VMD_MEMBAR1];
 847	upper_bits = upper_32_bits(res->end);
 848	flags = res->flags & ~IORESOURCE_SIZEALIGN;
 849	if (!upper_bits)
 850		flags &= ~IORESOURCE_MEM_64;
 851	vmd->resources[1] = (struct resource) {
 852		.name  = "VMD MEMBAR1",
 853		.start = res->start,
 854		.end   = res->end,
 855		.flags = flags,
 856		.parent = res,
 857	};
 858
 859	res = &vmd->dev->resource[VMD_MEMBAR2];
 860	upper_bits = upper_32_bits(res->end);
 861	flags = res->flags & ~IORESOURCE_SIZEALIGN;
 862	if (!upper_bits)
 863		flags &= ~IORESOURCE_MEM_64;
 864	vmd->resources[2] = (struct resource) {
 865		.name  = "VMD MEMBAR2",
 866		.start = res->start + membar2_offset,
 867		.end   = res->end,
 868		.flags = flags,
 869		.parent = res,
 870	};
 871
 872	sd->vmd_dev = vmd->dev;
 873	sd->domain = vmd_find_free_domain();
 874	if (sd->domain < 0)
 875		return sd->domain;
 876
 877	sd->node = pcibus_to_node(vmd->dev->bus);
 878
 879	/*
 880	 * Currently MSI remapping must be enabled in guest passthrough mode
 881	 * due to some missing interrupt remapping plumbing. This is probably
 882	 * acceptable because the guest is usually CPU-limited and MSI
 883	 * remapping doesn't become a performance bottleneck.
 884	 */
 885	if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) ||
 886	    offset[0] || offset[1]) {
 887		ret = vmd_alloc_irqs(vmd);
 888		if (ret)
 889			return ret;
 890
 891		vmd_set_msi_remapping(vmd, true);
 892
 893		ret = vmd_create_irq_domain(vmd);
 894		if (ret)
 895			return ret;
 896
 897		/*
 898		 * Override the IRQ domain bus token so the domain can be
 899		 * distinguished from a regular PCI/MSI domain.
 900		 */
 901		irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
 902	} else {
 903		vmd_set_msi_remapping(vmd, false);
 904	}
 905
 906	pci_add_resource(&resources, &vmd->resources[0]);
 907	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
 908	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
 909
 910	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
 911				       &vmd_ops, sd, &resources);
 912	if (!vmd->bus) {
 913		pci_free_resource_list(&resources);
 914		vmd_remove_irq_domain(vmd);
 915		return -ENODEV;
 916	}
 917
 918	vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
 919				   to_pci_host_bridge(vmd->bus->bridge));
 920
 921	vmd_attach_resources(vmd);
 922	if (vmd->irq_domain)
 923		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
 924	else
 925		dev_set_msi_domain(&vmd->bus->dev,
 926				   dev_get_msi_domain(&vmd->dev->dev));
 927
 928	vmd_acpi_begin();
 929
 930	pci_scan_child_bus(vmd->bus);
 931	vmd_domain_reset(vmd);
 932
 933	/* When Intel VMD is enabled, the OS does not discover the Root Ports
 934	 * owned by Intel VMD within the MMCFG space. pci_reset_bus() applies
 935	 * a reset to the parent of the PCI device supplied as argument. This
 936	 * is why we pass a child device, so the reset can be triggered at
 937	 * the Intel bridge level and propagated to all the children in the
 938	 * hierarchy.
 939	 */
 940	list_for_each_entry(child, &vmd->bus->children, node) {
 941		if (!list_empty(&child->devices)) {
 942			dev = list_first_entry(&child->devices,
 943					       struct pci_dev, bus_list);
 944			ret = pci_reset_bus(dev);
 945			if (ret)
 946				pci_warn(dev, "can't reset device: %d\n", ret);
 947
 948			break;
 949		}
 950	}
 951
 952	pci_assign_unassigned_bus_resources(vmd->bus);
 953
 954	pci_walk_bus(vmd->bus, vmd_pm_enable_quirk, &features);
 955
 956	/*
 957	 * VMD root buses are virtual and don't return true on pci_is_pcie()
 958	 * and will fail pcie_bus_configure_settings() early. It can instead be
 959	 * run on each of the real root ports.
 960	 */
 961	list_for_each_entry(child, &vmd->bus->children, node)
 962		pcie_bus_configure_settings(child);
 963
 964	pci_bus_add_devices(vmd->bus);
 965
 966	vmd_acpi_end();
 967
 968	WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
 969			       "domain"), "Can't create symlink to domain\n");
 970	return 0;
 971}
 972
 973static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 974{
 975	unsigned long features = (unsigned long) id->driver_data;
 976	struct vmd_dev *vmd;
 977	int err;
 978
 979	if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
 980		return -ENOMEM;
 981
 982	vmd = devm_kzalloc(&dev->dev, sizeof(*vmd), GFP_KERNEL);
 983	if (!vmd)
 984		return -ENOMEM;
 985
 986	vmd->dev = dev;
 987	vmd->instance = ida_alloc(&vmd_instance_ida, GFP_KERNEL);
 988	if (vmd->instance < 0)
 989		return vmd->instance;
 990
 991	vmd->name = devm_kasprintf(&dev->dev, GFP_KERNEL, "vmd%d",
 992				   vmd->instance);
 993	if (!vmd->name) {
 994		err = -ENOMEM;
 995		goto out_release_instance;
 996	}
 997
 998	err = pcim_enable_device(dev);
 999	if (err < 0)
1000		goto out_release_instance;
1001
1002	vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
1003	if (!vmd->cfgbar) {
1004		err = -ENOMEM;
1005		goto out_release_instance;
1006	}
1007
1008	pci_set_master(dev);
1009	if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
1010	    dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32))) {
1011		err = -ENODEV;
1012		goto out_release_instance;
1013	}
1014
1015	if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
1016		vmd->first_vec = 1;
1017
1018	spin_lock_init(&vmd->cfg_lock);
1019	pci_set_drvdata(dev, vmd);
1020	err = vmd_enable_domain(vmd, features);
1021	if (err)
1022		goto out_release_instance;
1023
1024	dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
1025		 vmd->sysdata.domain);
1026	return 0;
1027
1028 out_release_instance:
1029	ida_free(&vmd_instance_ida, vmd->instance);
1030	return err;
1031}
1032
1033static void vmd_cleanup_srcu(struct vmd_dev *vmd)
1034{
1035	int i;
1036
1037	for (i = 0; i < vmd->msix_count; i++)
1038		cleanup_srcu_struct(&vmd->irqs[i].srcu);
1039}
1040
1041static void vmd_remove(struct pci_dev *dev)
1042{
1043	struct vmd_dev *vmd = pci_get_drvdata(dev);
1044
1045	sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
1046	pci_stop_root_bus(vmd->bus);
1047	pci_remove_root_bus(vmd->bus);
1048	vmd_cleanup_srcu(vmd);
1049	vmd_detach_resources(vmd);
1050	vmd_remove_irq_domain(vmd);
1051	ida_free(&vmd_instance_ida, vmd->instance);
1052}
1053
1054static void vmd_shutdown(struct pci_dev *dev)
1055{
1056        struct vmd_dev *vmd = pci_get_drvdata(dev);
1057
1058        vmd_remove_irq_domain(vmd);
1059}
1060
1061#ifdef CONFIG_PM_SLEEP
1062static int vmd_suspend(struct device *dev)
1063{
1064	struct pci_dev *pdev = to_pci_dev(dev);
1065	struct vmd_dev *vmd = pci_get_drvdata(pdev);
1066	int i;
1067
1068	for (i = 0; i < vmd->msix_count; i++)
1069		devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]);
1070
1071	return 0;
1072}
1073
1074static int vmd_resume(struct device *dev)
1075{
1076	struct pci_dev *pdev = to_pci_dev(dev);
1077	struct vmd_dev *vmd = pci_get_drvdata(pdev);
1078	int err, i;
1079
1080	vmd_set_msi_remapping(vmd, !!vmd->irq_domain);
1081
1082	for (i = 0; i < vmd->msix_count; i++) {
1083		err = devm_request_irq(dev, vmd->irqs[i].virq,
1084				       vmd_irq, IRQF_NO_THREAD,
1085				       vmd->name, &vmd->irqs[i]);
1086		if (err)
1087			return err;
1088	}
1089
1090	return 0;
1091}
1092#endif
1093static SIMPLE_DEV_PM_OPS(vmd_dev_pm_ops, vmd_suspend, vmd_resume);
1094
1095static const struct pci_device_id vmd_ids[] = {
1096	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_201D),
1097		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP,},
1098	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_28C0),
1099		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
1100				VMD_FEAT_HAS_BUS_RESTRICTIONS |
1101				VMD_FEAT_CAN_BYPASS_MSI_REMAP,},
1102	{PCI_VDEVICE(INTEL, 0x467f),
1103		.driver_data = VMD_FEATS_CLIENT,},
1104	{PCI_VDEVICE(INTEL, 0x4c3d),
1105		.driver_data = VMD_FEATS_CLIENT,},
1106	{PCI_VDEVICE(INTEL, 0xa77f),
1107		.driver_data = VMD_FEATS_CLIENT,},
1108	{PCI_VDEVICE(INTEL, 0x7d0b),
1109		.driver_data = VMD_FEATS_CLIENT,},
1110	{PCI_VDEVICE(INTEL, 0xad0b),
1111		.driver_data = VMD_FEATS_CLIENT,},
1112	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
1113		.driver_data = VMD_FEATS_CLIENT,},
1114	{0,}
1115};
1116MODULE_DEVICE_TABLE(pci, vmd_ids);
1117
1118static struct pci_driver vmd_drv = {
1119	.name		= "vmd",
1120	.id_table	= vmd_ids,
1121	.probe		= vmd_probe,
1122	.remove		= vmd_remove,
1123	.shutdown	= vmd_shutdown,
1124	.driver		= {
1125		.pm	= &vmd_dev_pm_ops,
1126	},
1127};
1128module_pci_driver(vmd_drv);
1129
1130MODULE_AUTHOR("Intel Corporation");
1131MODULE_LICENSE("GPL v2");
1132MODULE_VERSION("0.6");