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   1/*
   2 * IBM PowerPC Virtual I/O Infrastructure Support.
   3 *
   4 *    Copyright (c) 2003,2008 IBM Corp.
   5 *     Dave Engebretsen engebret@us.ibm.com
   6 *     Santiago Leon santil@us.ibm.com
   7 *     Hollis Blanchard <hollisb@us.ibm.com>
   8 *     Stephen Rothwell
   9 *     Robert Jennings <rcjenn@us.ibm.com>
  10 *
  11 *      This program is free software; you can redistribute it and/or
  12 *      modify it under the terms of the GNU General Public License
  13 *      as published by the Free Software Foundation; either version
  14 *      2 of the License, or (at your option) any later version.
  15 */
  16
  17#include <linux/cpu.h>
  18#include <linux/types.h>
  19#include <linux/delay.h>
  20#include <linux/stat.h>
  21#include <linux/device.h>
  22#include <linux/init.h>
  23#include <linux/slab.h>
  24#include <linux/console.h>
  25#include <linux/export.h>
  26#include <linux/mm.h>
  27#include <linux/dma-mapping.h>
  28#include <linux/kobject.h>
  29
  30#include <asm/iommu.h>
  31#include <asm/dma.h>
  32#include <asm/vio.h>
  33#include <asm/prom.h>
  34#include <asm/firmware.h>
  35#include <asm/tce.h>
  36#include <asm/page.h>
  37#include <asm/hvcall.h>
  38
  39static struct vio_dev vio_bus_device  = { /* fake "parent" device */
  40	.name = "vio",
  41	.type = "",
  42	.dev.init_name = "vio",
  43	.dev.bus = &vio_bus_type,
  44};
  45
  46#ifdef CONFIG_PPC_SMLPAR
  47/**
  48 * vio_cmo_pool - A pool of IO memory for CMO use
  49 *
  50 * @size: The size of the pool in bytes
  51 * @free: The amount of free memory in the pool
  52 */
  53struct vio_cmo_pool {
  54	size_t size;
  55	size_t free;
  56};
  57
  58/* How many ms to delay queued balance work */
  59#define VIO_CMO_BALANCE_DELAY 100
  60
  61/* Portion out IO memory to CMO devices by this chunk size */
  62#define VIO_CMO_BALANCE_CHUNK 131072
  63
  64/**
  65 * vio_cmo_dev_entry - A device that is CMO-enabled and requires entitlement
  66 *
  67 * @vio_dev: struct vio_dev pointer
  68 * @list: pointer to other devices on bus that are being tracked
  69 */
  70struct vio_cmo_dev_entry {
  71	struct vio_dev *viodev;
  72	struct list_head list;
  73};
  74
  75/**
  76 * vio_cmo - VIO bus accounting structure for CMO entitlement
  77 *
  78 * @lock: spinlock for entire structure
  79 * @balance_q: work queue for balancing system entitlement
  80 * @device_list: list of CMO-enabled devices requiring entitlement
  81 * @entitled: total system entitlement in bytes
  82 * @reserve: pool of memory from which devices reserve entitlement, incl. spare
  83 * @excess: pool of excess entitlement not needed for device reserves or spare
  84 * @spare: IO memory for device hotplug functionality
  85 * @min: minimum necessary for system operation
  86 * @desired: desired memory for system operation
  87 * @curr: bytes currently allocated
  88 * @high: high water mark for IO data usage
  89 */
  90struct vio_cmo {
  91	spinlock_t lock;
  92	struct delayed_work balance_q;
  93	struct list_head device_list;
  94	size_t entitled;
  95	struct vio_cmo_pool reserve;
  96	struct vio_cmo_pool excess;
  97	size_t spare;
  98	size_t min;
  99	size_t desired;
 100	size_t curr;
 101	size_t high;
 102} vio_cmo;
 103
 104/**
 105 * vio_cmo_OF_devices - Count the number of OF devices that have DMA windows
 106 */
 107static int vio_cmo_num_OF_devs(void)
 108{
 109	struct device_node *node_vroot;
 110	int count = 0;
 111
 112	/*
 113	 * Count the number of vdevice entries with an
 114	 * ibm,my-dma-window OF property
 115	 */
 116	node_vroot = of_find_node_by_name(NULL, "vdevice");
 117	if (node_vroot) {
 118		struct device_node *of_node;
 119		struct property *prop;
 120
 121		for_each_child_of_node(node_vroot, of_node) {
 122			prop = of_find_property(of_node, "ibm,my-dma-window",
 123			                       NULL);
 124			if (prop)
 125				count++;
 126		}
 127	}
 128	of_node_put(node_vroot);
 129	return count;
 130}
 131
 132/**
 133 * vio_cmo_alloc - allocate IO memory for CMO-enable devices
 134 *
 135 * @viodev: VIO device requesting IO memory
 136 * @size: size of allocation requested
 137 *
 138 * Allocations come from memory reserved for the devices and any excess
 139 * IO memory available to all devices.  The spare pool used to service
 140 * hotplug must be equal to %VIO_CMO_MIN_ENT for the excess pool to be
 141 * made available.
 142 *
 143 * Return codes:
 144 *  0 for successful allocation and -ENOMEM for a failure
 145 */
 146static inline int vio_cmo_alloc(struct vio_dev *viodev, size_t size)
 147{
 148	unsigned long flags;
 149	size_t reserve_free = 0;
 150	size_t excess_free = 0;
 151	int ret = -ENOMEM;
 152
 153	spin_lock_irqsave(&vio_cmo.lock, flags);
 154
 155	/* Determine the amount of free entitlement available in reserve */
 156	if (viodev->cmo.entitled > viodev->cmo.allocated)
 157		reserve_free = viodev->cmo.entitled - viodev->cmo.allocated;
 158
 159	/* If spare is not fulfilled, the excess pool can not be used. */
 160	if (vio_cmo.spare >= VIO_CMO_MIN_ENT)
 161		excess_free = vio_cmo.excess.free;
 162
 163	/* The request can be satisfied */
 164	if ((reserve_free + excess_free) >= size) {
 165		vio_cmo.curr += size;
 166		if (vio_cmo.curr > vio_cmo.high)
 167			vio_cmo.high = vio_cmo.curr;
 168		viodev->cmo.allocated += size;
 169		size -= min(reserve_free, size);
 170		vio_cmo.excess.free -= size;
 171		ret = 0;
 172	}
 173
 174	spin_unlock_irqrestore(&vio_cmo.lock, flags);
 175	return ret;
 176}
 177
 178/**
 179 * vio_cmo_dealloc - deallocate IO memory from CMO-enable devices
 180 * @viodev: VIO device freeing IO memory
 181 * @size: size of deallocation
 182 *
 183 * IO memory is freed by the device back to the correct memory pools.
 184 * The spare pool is replenished first from either memory pool, then
 185 * the reserve pool is used to reduce device entitlement, the excess
 186 * pool is used to increase the reserve pool toward the desired entitlement
 187 * target, and then the remaining memory is returned to the pools.
 188 *
 189 */
 190static inline void vio_cmo_dealloc(struct vio_dev *viodev, size_t size)
 191{
 192	unsigned long flags;
 193	size_t spare_needed = 0;
 194	size_t excess_freed = 0;
 195	size_t reserve_freed = size;
 196	size_t tmp;
 197	int balance = 0;
 198
 199	spin_lock_irqsave(&vio_cmo.lock, flags);
 200	vio_cmo.curr -= size;
 201
 202	/* Amount of memory freed from the excess pool */
 203	if (viodev->cmo.allocated > viodev->cmo.entitled) {
 204		excess_freed = min(reserve_freed, (viodev->cmo.allocated -
 205		                                   viodev->cmo.entitled));
 206		reserve_freed -= excess_freed;
 207	}
 208
 209	/* Remove allocation from device */
 210	viodev->cmo.allocated -= (reserve_freed + excess_freed);
 211
 212	/* Spare is a subset of the reserve pool, replenish it first. */
 213	spare_needed = VIO_CMO_MIN_ENT - vio_cmo.spare;
 214
 215	/*
 216	 * Replenish the spare in the reserve pool from the excess pool.
 217	 * This moves entitlement into the reserve pool.
 218	 */
 219	if (spare_needed && excess_freed) {
 220		tmp = min(excess_freed, spare_needed);
 221		vio_cmo.excess.size -= tmp;
 222		vio_cmo.reserve.size += tmp;
 223		vio_cmo.spare += tmp;
 224		excess_freed -= tmp;
 225		spare_needed -= tmp;
 226		balance = 1;
 227	}
 228
 229	/*
 230	 * Replenish the spare in the reserve pool from the reserve pool.
 231	 * This removes entitlement from the device down to VIO_CMO_MIN_ENT,
 232	 * if needed, and gives it to the spare pool. The amount of used
 233	 * memory in this pool does not change.
 234	 */
 235	if (spare_needed && reserve_freed) {
 236		tmp = min3(spare_needed, reserve_freed, (viodev->cmo.entitled - VIO_CMO_MIN_ENT));
 237
 238		vio_cmo.spare += tmp;
 239		viodev->cmo.entitled -= tmp;
 240		reserve_freed -= tmp;
 241		spare_needed -= tmp;
 242		balance = 1;
 243	}
 244
 245	/*
 246	 * Increase the reserve pool until the desired allocation is met.
 247	 * Move an allocation freed from the excess pool into the reserve
 248	 * pool and schedule a balance operation.
 249	 */
 250	if (excess_freed && (vio_cmo.desired > vio_cmo.reserve.size)) {
 251		tmp = min(excess_freed, (vio_cmo.desired - vio_cmo.reserve.size));
 252
 253		vio_cmo.excess.size -= tmp;
 254		vio_cmo.reserve.size += tmp;
 255		excess_freed -= tmp;
 256		balance = 1;
 257	}
 258
 259	/* Return memory from the excess pool to that pool */
 260	if (excess_freed)
 261		vio_cmo.excess.free += excess_freed;
 262
 263	if (balance)
 264		schedule_delayed_work(&vio_cmo.balance_q, VIO_CMO_BALANCE_DELAY);
 265	spin_unlock_irqrestore(&vio_cmo.lock, flags);
 266}
 267
 268/**
 269 * vio_cmo_entitlement_update - Manage system entitlement changes
 270 *
 271 * @new_entitlement: new system entitlement to attempt to accommodate
 272 *
 273 * Increases in entitlement will be used to fulfill the spare entitlement
 274 * and the rest is given to the excess pool.  Decreases, if they are
 275 * possible, come from the excess pool and from unused device entitlement
 276 *
 277 * Returns: 0 on success, -ENOMEM when change can not be made
 278 */
 279int vio_cmo_entitlement_update(size_t new_entitlement)
 280{
 281	struct vio_dev *viodev;
 282	struct vio_cmo_dev_entry *dev_ent;
 283	unsigned long flags;
 284	size_t avail, delta, tmp;
 285
 286	spin_lock_irqsave(&vio_cmo.lock, flags);
 287
 288	/* Entitlement increases */
 289	if (new_entitlement > vio_cmo.entitled) {
 290		delta = new_entitlement - vio_cmo.entitled;
 291
 292		/* Fulfill spare allocation */
 293		if (vio_cmo.spare < VIO_CMO_MIN_ENT) {
 294			tmp = min(delta, (VIO_CMO_MIN_ENT - vio_cmo.spare));
 295			vio_cmo.spare += tmp;
 296			vio_cmo.reserve.size += tmp;
 297			delta -= tmp;
 298		}
 299
 300		/* Remaining new allocation goes to the excess pool */
 301		vio_cmo.entitled += delta;
 302		vio_cmo.excess.size += delta;
 303		vio_cmo.excess.free += delta;
 304
 305		goto out;
 306	}
 307
 308	/* Entitlement decreases */
 309	delta = vio_cmo.entitled - new_entitlement;
 310	avail = vio_cmo.excess.free;
 311
 312	/*
 313	 * Need to check how much unused entitlement each device can
 314	 * sacrifice to fulfill entitlement change.
 315	 */
 316	list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 317		if (avail >= delta)
 318			break;
 319
 320		viodev = dev_ent->viodev;
 321		if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
 322		    (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
 323				avail += viodev->cmo.entitled -
 324				         max_t(size_t, viodev->cmo.allocated,
 325				               VIO_CMO_MIN_ENT);
 326	}
 327
 328	if (delta <= avail) {
 329		vio_cmo.entitled -= delta;
 330
 331		/* Take entitlement from the excess pool first */
 332		tmp = min(vio_cmo.excess.free, delta);
 333		vio_cmo.excess.size -= tmp;
 334		vio_cmo.excess.free -= tmp;
 335		delta -= tmp;
 336
 337		/*
 338		 * Remove all but VIO_CMO_MIN_ENT bytes from devices
 339		 * until entitlement change is served
 340		 */
 341		list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 342			if (!delta)
 343				break;
 344
 345			viodev = dev_ent->viodev;
 346			tmp = 0;
 347			if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
 348			    (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
 349				tmp = viodev->cmo.entitled -
 350				      max_t(size_t, viodev->cmo.allocated,
 351				            VIO_CMO_MIN_ENT);
 352			viodev->cmo.entitled -= min(tmp, delta);
 353			delta -= min(tmp, delta);
 354		}
 355	} else {
 356		spin_unlock_irqrestore(&vio_cmo.lock, flags);
 357		return -ENOMEM;
 358	}
 359
 360out:
 361	schedule_delayed_work(&vio_cmo.balance_q, 0);
 362	spin_unlock_irqrestore(&vio_cmo.lock, flags);
 363	return 0;
 364}
 365
 366/**
 367 * vio_cmo_balance - Balance entitlement among devices
 368 *
 369 * @work: work queue structure for this operation
 370 *
 371 * Any system entitlement above the minimum needed for devices, or
 372 * already allocated to devices, can be distributed to the devices.
 373 * The list of devices is iterated through to recalculate the desired
 374 * entitlement level and to determine how much entitlement above the
 375 * minimum entitlement is allocated to devices.
 376 *
 377 * Small chunks of the available entitlement are given to devices until
 378 * their requirements are fulfilled or there is no entitlement left to give.
 379 * Upon completion sizes of the reserve and excess pools are calculated.
 380 *
 381 * The system minimum entitlement level is also recalculated here.
 382 * Entitlement will be reserved for devices even after vio_bus_remove to
 383 * accommodate reloading the driver.  The OF tree is walked to count the
 384 * number of devices present and this will remove entitlement for devices
 385 * that have actually left the system after having vio_bus_remove called.
 386 */
 387static void vio_cmo_balance(struct work_struct *work)
 388{
 389	struct vio_cmo *cmo;
 390	struct vio_dev *viodev;
 391	struct vio_cmo_dev_entry *dev_ent;
 392	unsigned long flags;
 393	size_t avail = 0, level, chunk, need;
 394	int devcount = 0, fulfilled;
 395
 396	cmo = container_of(work, struct vio_cmo, balance_q.work);
 397
 398	spin_lock_irqsave(&vio_cmo.lock, flags);
 399
 400	/* Calculate minimum entitlement and fulfill spare */
 401	cmo->min = vio_cmo_num_OF_devs() * VIO_CMO_MIN_ENT;
 402	BUG_ON(cmo->min > cmo->entitled);
 403	cmo->spare = min_t(size_t, VIO_CMO_MIN_ENT, (cmo->entitled - cmo->min));
 404	cmo->min += cmo->spare;
 405	cmo->desired = cmo->min;
 406
 407	/*
 408	 * Determine how much entitlement is available and reset device
 409	 * entitlements
 410	 */
 411	avail = cmo->entitled - cmo->spare;
 412	list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 413		viodev = dev_ent->viodev;
 414		devcount++;
 415		viodev->cmo.entitled = VIO_CMO_MIN_ENT;
 416		cmo->desired += (viodev->cmo.desired - VIO_CMO_MIN_ENT);
 417		avail -= max_t(size_t, viodev->cmo.allocated, VIO_CMO_MIN_ENT);
 418	}
 419
 420	/*
 421	 * Having provided each device with the minimum entitlement, loop
 422	 * over the devices portioning out the remaining entitlement
 423	 * until there is nothing left.
 424	 */
 425	level = VIO_CMO_MIN_ENT;
 426	while (avail) {
 427		fulfilled = 0;
 428		list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 429			viodev = dev_ent->viodev;
 430
 431			if (viodev->cmo.desired <= level) {
 432				fulfilled++;
 433				continue;
 434			}
 435
 436			/*
 437			 * Give the device up to VIO_CMO_BALANCE_CHUNK
 438			 * bytes of entitlement, but do not exceed the
 439			 * desired level of entitlement for the device.
 440			 */
 441			chunk = min_t(size_t, avail, VIO_CMO_BALANCE_CHUNK);
 442			chunk = min(chunk, (viodev->cmo.desired -
 443			                    viodev->cmo.entitled));
 444			viodev->cmo.entitled += chunk;
 445
 446			/*
 447			 * If the memory for this entitlement increase was
 448			 * already allocated to the device it does not come
 449			 * from the available pool being portioned out.
 450			 */
 451			need = max(viodev->cmo.allocated, viodev->cmo.entitled)-
 452			       max(viodev->cmo.allocated, level);
 453			avail -= need;
 454
 455		}
 456		if (fulfilled == devcount)
 457			break;
 458		level += VIO_CMO_BALANCE_CHUNK;
 459	}
 460
 461	/* Calculate new reserve and excess pool sizes */
 462	cmo->reserve.size = cmo->min;
 463	cmo->excess.free = 0;
 464	cmo->excess.size = 0;
 465	need = 0;
 466	list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 467		viodev = dev_ent->viodev;
 468		/* Calculated reserve size above the minimum entitlement */
 469		if (viodev->cmo.entitled)
 470			cmo->reserve.size += (viodev->cmo.entitled -
 471			                      VIO_CMO_MIN_ENT);
 472		/* Calculated used excess entitlement */
 473		if (viodev->cmo.allocated > viodev->cmo.entitled)
 474			need += viodev->cmo.allocated - viodev->cmo.entitled;
 475	}
 476	cmo->excess.size = cmo->entitled - cmo->reserve.size;
 477	cmo->excess.free = cmo->excess.size - need;
 478
 479	cancel_delayed_work(to_delayed_work(work));
 480	spin_unlock_irqrestore(&vio_cmo.lock, flags);
 481}
 482
 483static void *vio_dma_iommu_alloc_coherent(struct device *dev, size_t size,
 484					  dma_addr_t *dma_handle, gfp_t flag,
 485					  struct dma_attrs *attrs)
 486{
 487	struct vio_dev *viodev = to_vio_dev(dev);
 488	void *ret;
 489
 490	if (vio_cmo_alloc(viodev, roundup(size, PAGE_SIZE))) {
 491		atomic_inc(&viodev->cmo.allocs_failed);
 492		return NULL;
 493	}
 494
 495	ret = dma_iommu_ops.alloc(dev, size, dma_handle, flag, attrs);
 496	if (unlikely(ret == NULL)) {
 497		vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
 498		atomic_inc(&viodev->cmo.allocs_failed);
 499	}
 500
 501	return ret;
 502}
 503
 504static void vio_dma_iommu_free_coherent(struct device *dev, size_t size,
 505					void *vaddr, dma_addr_t dma_handle,
 506					struct dma_attrs *attrs)
 507{
 508	struct vio_dev *viodev = to_vio_dev(dev);
 509
 510	dma_iommu_ops.free(dev, size, vaddr, dma_handle, attrs);
 511
 512	vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
 513}
 514
 515static dma_addr_t vio_dma_iommu_map_page(struct device *dev, struct page *page,
 516                                         unsigned long offset, size_t size,
 517                                         enum dma_data_direction direction,
 518                                         struct dma_attrs *attrs)
 519{
 520	struct vio_dev *viodev = to_vio_dev(dev);
 521	struct iommu_table *tbl;
 522	dma_addr_t ret = DMA_ERROR_CODE;
 523
 524	tbl = get_iommu_table_base(dev);
 525	if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)))) {
 526		atomic_inc(&viodev->cmo.allocs_failed);
 527		return ret;
 528	}
 529
 530	ret = dma_iommu_ops.map_page(dev, page, offset, size, direction, attrs);
 531	if (unlikely(dma_mapping_error(dev, ret))) {
 532		vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
 533		atomic_inc(&viodev->cmo.allocs_failed);
 534	}
 535
 536	return ret;
 537}
 538
 539static void vio_dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
 540				     size_t size,
 541				     enum dma_data_direction direction,
 542				     struct dma_attrs *attrs)
 543{
 544	struct vio_dev *viodev = to_vio_dev(dev);
 545	struct iommu_table *tbl;
 546
 547	tbl = get_iommu_table_base(dev);
 548	dma_iommu_ops.unmap_page(dev, dma_handle, size, direction, attrs);
 549
 550	vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
 551}
 552
 553static int vio_dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
 554                                int nelems, enum dma_data_direction direction,
 555                                struct dma_attrs *attrs)
 556{
 557	struct vio_dev *viodev = to_vio_dev(dev);
 558	struct iommu_table *tbl;
 559	struct scatterlist *sgl;
 560	int ret, count;
 561	size_t alloc_size = 0;
 562
 563	tbl = get_iommu_table_base(dev);
 564	for_each_sg(sglist, sgl, nelems, count)
 565		alloc_size += roundup(sgl->length, IOMMU_PAGE_SIZE(tbl));
 566
 567	if (vio_cmo_alloc(viodev, alloc_size)) {
 568		atomic_inc(&viodev->cmo.allocs_failed);
 569		return 0;
 570	}
 571
 572	ret = dma_iommu_ops.map_sg(dev, sglist, nelems, direction, attrs);
 573
 574	if (unlikely(!ret)) {
 575		vio_cmo_dealloc(viodev, alloc_size);
 576		atomic_inc(&viodev->cmo.allocs_failed);
 577		return ret;
 578	}
 579
 580	for_each_sg(sglist, sgl, ret, count)
 581		alloc_size -= roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
 582	if (alloc_size)
 583		vio_cmo_dealloc(viodev, alloc_size);
 584
 585	return ret;
 586}
 587
 588static void vio_dma_iommu_unmap_sg(struct device *dev,
 589		struct scatterlist *sglist, int nelems,
 590		enum dma_data_direction direction,
 591		struct dma_attrs *attrs)
 592{
 593	struct vio_dev *viodev = to_vio_dev(dev);
 594	struct iommu_table *tbl;
 595	struct scatterlist *sgl;
 596	size_t alloc_size = 0;
 597	int count;
 598
 599	tbl = get_iommu_table_base(dev);
 600	for_each_sg(sglist, sgl, nelems, count)
 601		alloc_size += roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
 602
 603	dma_iommu_ops.unmap_sg(dev, sglist, nelems, direction, attrs);
 604
 605	vio_cmo_dealloc(viodev, alloc_size);
 606}
 607
 608static int vio_dma_iommu_dma_supported(struct device *dev, u64 mask)
 609{
 610        return dma_iommu_ops.dma_supported(dev, mask);
 611}
 612
 613static u64 vio_dma_get_required_mask(struct device *dev)
 614{
 615        return dma_iommu_ops.get_required_mask(dev);
 616}
 617
 618struct dma_map_ops vio_dma_mapping_ops = {
 619	.alloc             = vio_dma_iommu_alloc_coherent,
 620	.free              = vio_dma_iommu_free_coherent,
 621	.mmap		   = dma_direct_mmap_coherent,
 622	.map_sg            = vio_dma_iommu_map_sg,
 623	.unmap_sg          = vio_dma_iommu_unmap_sg,
 624	.map_page          = vio_dma_iommu_map_page,
 625	.unmap_page        = vio_dma_iommu_unmap_page,
 626	.dma_supported     = vio_dma_iommu_dma_supported,
 627	.get_required_mask = vio_dma_get_required_mask,
 628};
 629
 630/**
 631 * vio_cmo_set_dev_desired - Set desired entitlement for a device
 632 *
 633 * @viodev: struct vio_dev for device to alter
 634 * @desired: new desired entitlement level in bytes
 635 *
 636 * For use by devices to request a change to their entitlement at runtime or
 637 * through sysfs.  The desired entitlement level is changed and a balancing
 638 * of system resources is scheduled to run in the future.
 639 */
 640void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired)
 641{
 642	unsigned long flags;
 643	struct vio_cmo_dev_entry *dev_ent;
 644	int found = 0;
 645
 646	if (!firmware_has_feature(FW_FEATURE_CMO))
 647		return;
 648
 649	spin_lock_irqsave(&vio_cmo.lock, flags);
 650	if (desired < VIO_CMO_MIN_ENT)
 651		desired = VIO_CMO_MIN_ENT;
 652
 653	/*
 654	 * Changes will not be made for devices not in the device list.
 655	 * If it is not in the device list, then no driver is loaded
 656	 * for the device and it can not receive entitlement.
 657	 */
 658	list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
 659		if (viodev == dev_ent->viodev) {
 660			found = 1;
 661			break;
 662		}
 663	if (!found) {
 664		spin_unlock_irqrestore(&vio_cmo.lock, flags);
 665		return;
 666	}
 667
 668	/* Increase/decrease in desired device entitlement */
 669	if (desired >= viodev->cmo.desired) {
 670		/* Just bump the bus and device values prior to a balance*/
 671		vio_cmo.desired += desired - viodev->cmo.desired;
 672		viodev->cmo.desired = desired;
 673	} else {
 674		/* Decrease bus and device values for desired entitlement */
 675		vio_cmo.desired -= viodev->cmo.desired - desired;
 676		viodev->cmo.desired = desired;
 677		/*
 678		 * If less entitlement is desired than current entitlement, move
 679		 * any reserve memory in the change region to the excess pool.
 680		 */
 681		if (viodev->cmo.entitled > desired) {
 682			vio_cmo.reserve.size -= viodev->cmo.entitled - desired;
 683			vio_cmo.excess.size += viodev->cmo.entitled - desired;
 684			/*
 685			 * If entitlement moving from the reserve pool to the
 686			 * excess pool is currently unused, add to the excess
 687			 * free counter.
 688			 */
 689			if (viodev->cmo.allocated < viodev->cmo.entitled)
 690				vio_cmo.excess.free += viodev->cmo.entitled -
 691				                       max(viodev->cmo.allocated, desired);
 692			viodev->cmo.entitled = desired;
 693		}
 694	}
 695	schedule_delayed_work(&vio_cmo.balance_q, 0);
 696	spin_unlock_irqrestore(&vio_cmo.lock, flags);
 697}
 698
 699/**
 700 * vio_cmo_bus_probe - Handle CMO specific bus probe activities
 701 *
 702 * @viodev - Pointer to struct vio_dev for device
 703 *
 704 * Determine the devices IO memory entitlement needs, attempting
 705 * to satisfy the system minimum entitlement at first and scheduling
 706 * a balance operation to take care of the rest at a later time.
 707 *
 708 * Returns: 0 on success, -EINVAL when device doesn't support CMO, and
 709 *          -ENOMEM when entitlement is not available for device or
 710 *          device entry.
 711 *
 712 */
 713static int vio_cmo_bus_probe(struct vio_dev *viodev)
 714{
 715	struct vio_cmo_dev_entry *dev_ent;
 716	struct device *dev = &viodev->dev;
 717	struct iommu_table *tbl;
 718	struct vio_driver *viodrv = to_vio_driver(dev->driver);
 719	unsigned long flags;
 720	size_t size;
 721	bool dma_capable = false;
 722
 723	tbl = get_iommu_table_base(dev);
 724
 725	/* A device requires entitlement if it has a DMA window property */
 726	switch (viodev->family) {
 727	case VDEVICE:
 728		if (of_get_property(viodev->dev.of_node,
 729					"ibm,my-dma-window", NULL))
 730			dma_capable = true;
 731		break;
 732	case PFO:
 733		dma_capable = false;
 734		break;
 735	default:
 736		dev_warn(dev, "unknown device family: %d\n", viodev->family);
 737		BUG();
 738		break;
 739	}
 740
 741	/* Configure entitlement for the device. */
 742	if (dma_capable) {
 743		/* Check that the driver is CMO enabled and get desired DMA */
 744		if (!viodrv->get_desired_dma) {
 745			dev_err(dev, "%s: device driver does not support CMO\n",
 746			        __func__);
 747			return -EINVAL;
 748		}
 749
 750		viodev->cmo.desired =
 751			IOMMU_PAGE_ALIGN(viodrv->get_desired_dma(viodev), tbl);
 752		if (viodev->cmo.desired < VIO_CMO_MIN_ENT)
 753			viodev->cmo.desired = VIO_CMO_MIN_ENT;
 754		size = VIO_CMO_MIN_ENT;
 755
 756		dev_ent = kmalloc(sizeof(struct vio_cmo_dev_entry),
 757		                  GFP_KERNEL);
 758		if (!dev_ent)
 759			return -ENOMEM;
 760
 761		dev_ent->viodev = viodev;
 762		spin_lock_irqsave(&vio_cmo.lock, flags);
 763		list_add(&dev_ent->list, &vio_cmo.device_list);
 764	} else {
 765		viodev->cmo.desired = 0;
 766		size = 0;
 767		spin_lock_irqsave(&vio_cmo.lock, flags);
 768	}
 769
 770	/*
 771	 * If the needs for vio_cmo.min have not changed since they
 772	 * were last set, the number of devices in the OF tree has
 773	 * been constant and the IO memory for this is already in
 774	 * the reserve pool.
 775	 */
 776	if (vio_cmo.min == ((vio_cmo_num_OF_devs() + 1) *
 777	                    VIO_CMO_MIN_ENT)) {
 778		/* Updated desired entitlement if device requires it */
 779		if (size)
 780			vio_cmo.desired += (viodev->cmo.desired -
 781		                        VIO_CMO_MIN_ENT);
 782	} else {
 783		size_t tmp;
 784
 785		tmp = vio_cmo.spare + vio_cmo.excess.free;
 786		if (tmp < size) {
 787			dev_err(dev, "%s: insufficient free "
 788			        "entitlement to add device. "
 789			        "Need %lu, have %lu\n", __func__,
 790				size, (vio_cmo.spare + tmp));
 791			spin_unlock_irqrestore(&vio_cmo.lock, flags);
 792			return -ENOMEM;
 793		}
 794
 795		/* Use excess pool first to fulfill request */
 796		tmp = min(size, vio_cmo.excess.free);
 797		vio_cmo.excess.free -= tmp;
 798		vio_cmo.excess.size -= tmp;
 799		vio_cmo.reserve.size += tmp;
 800
 801		/* Use spare if excess pool was insufficient */
 802		vio_cmo.spare -= size - tmp;
 803
 804		/* Update bus accounting */
 805		vio_cmo.min += size;
 806		vio_cmo.desired += viodev->cmo.desired;
 807	}
 808	spin_unlock_irqrestore(&vio_cmo.lock, flags);
 809	return 0;
 810}
 811
 812/**
 813 * vio_cmo_bus_remove - Handle CMO specific bus removal activities
 814 *
 815 * @viodev - Pointer to struct vio_dev for device
 816 *
 817 * Remove the device from the cmo device list.  The minimum entitlement
 818 * will be reserved for the device as long as it is in the system.  The
 819 * rest of the entitlement the device had been allocated will be returned
 820 * to the system.
 821 */
 822static void vio_cmo_bus_remove(struct vio_dev *viodev)
 823{
 824	struct vio_cmo_dev_entry *dev_ent;
 825	unsigned long flags;
 826	size_t tmp;
 827
 828	spin_lock_irqsave(&vio_cmo.lock, flags);
 829	if (viodev->cmo.allocated) {
 830		dev_err(&viodev->dev, "%s: device had %lu bytes of IO "
 831		        "allocated after remove operation.\n",
 832		        __func__, viodev->cmo.allocated);
 833		BUG();
 834	}
 835
 836	/*
 837	 * Remove the device from the device list being maintained for
 838	 * CMO enabled devices.
 839	 */
 840	list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
 841		if (viodev == dev_ent->viodev) {
 842			list_del(&dev_ent->list);
 843			kfree(dev_ent);
 844			break;
 845		}
 846
 847	/*
 848	 * Devices may not require any entitlement and they do not need
 849	 * to be processed.  Otherwise, return the device's entitlement
 850	 * back to the pools.
 851	 */
 852	if (viodev->cmo.entitled) {
 853		/*
 854		 * This device has not yet left the OF tree, it's
 855		 * minimum entitlement remains in vio_cmo.min and
 856		 * vio_cmo.desired
 857		 */
 858		vio_cmo.desired -= (viodev->cmo.desired - VIO_CMO_MIN_ENT);
 859
 860		/*
 861		 * Save min allocation for device in reserve as long
 862		 * as it exists in OF tree as determined by later
 863		 * balance operation
 864		 */
 865		viodev->cmo.entitled -= VIO_CMO_MIN_ENT;
 866
 867		/* Replenish spare from freed reserve pool */
 868		if (viodev->cmo.entitled && (vio_cmo.spare < VIO_CMO_MIN_ENT)) {
 869			tmp = min(viodev->cmo.entitled, (VIO_CMO_MIN_ENT -
 870			                                 vio_cmo.spare));
 871			vio_cmo.spare += tmp;
 872			viodev->cmo.entitled -= tmp;
 873		}
 874
 875		/* Remaining reserve goes to excess pool */
 876		vio_cmo.excess.size += viodev->cmo.entitled;
 877		vio_cmo.excess.free += viodev->cmo.entitled;
 878		vio_cmo.reserve.size -= viodev->cmo.entitled;
 879
 880		/*
 881		 * Until the device is removed it will keep a
 882		 * minimum entitlement; this will guarantee that
 883		 * a module unload/load will result in a success.
 884		 */
 885		viodev->cmo.entitled = VIO_CMO_MIN_ENT;
 886		viodev->cmo.desired = VIO_CMO_MIN_ENT;
 887		atomic_set(&viodev->cmo.allocs_failed, 0);
 888	}
 889
 890	spin_unlock_irqrestore(&vio_cmo.lock, flags);
 891}
 892
 893static void vio_cmo_set_dma_ops(struct vio_dev *viodev)
 894{
 895	set_dma_ops(&viodev->dev, &vio_dma_mapping_ops);
 896}
 897
 898/**
 899 * vio_cmo_bus_init - CMO entitlement initialization at bus init time
 900 *
 901 * Set up the reserve and excess entitlement pools based on available
 902 * system entitlement and the number of devices in the OF tree that
 903 * require entitlement in the reserve pool.
 904 */
 905static void vio_cmo_bus_init(void)
 906{
 907	struct hvcall_mpp_data mpp_data;
 908	int err;
 909
 910	memset(&vio_cmo, 0, sizeof(struct vio_cmo));
 911	spin_lock_init(&vio_cmo.lock);
 912	INIT_LIST_HEAD(&vio_cmo.device_list);
 913	INIT_DELAYED_WORK(&vio_cmo.balance_q, vio_cmo_balance);
 914
 915	/* Get current system entitlement */
 916	err = h_get_mpp(&mpp_data);
 917
 918	/*
 919	 * On failure, continue with entitlement set to 0, will panic()
 920	 * later when spare is reserved.
 921	 */
 922	if (err != H_SUCCESS) {
 923		printk(KERN_ERR "%s: unable to determine system IO "\
 924		       "entitlement. (%d)\n", __func__, err);
 925		vio_cmo.entitled = 0;
 926	} else {
 927		vio_cmo.entitled = mpp_data.entitled_mem;
 928	}
 929
 930	/* Set reservation and check against entitlement */
 931	vio_cmo.spare = VIO_CMO_MIN_ENT;
 932	vio_cmo.reserve.size = vio_cmo.spare;
 933	vio_cmo.reserve.size += (vio_cmo_num_OF_devs() *
 934	                         VIO_CMO_MIN_ENT);
 935	if (vio_cmo.reserve.size > vio_cmo.entitled) {
 936		printk(KERN_ERR "%s: insufficient system entitlement\n",
 937		       __func__);
 938		panic("%s: Insufficient system entitlement", __func__);
 939	}
 940
 941	/* Set the remaining accounting variables */
 942	vio_cmo.excess.size = vio_cmo.entitled - vio_cmo.reserve.size;
 943	vio_cmo.excess.free = vio_cmo.excess.size;
 944	vio_cmo.min = vio_cmo.reserve.size;
 945	vio_cmo.desired = vio_cmo.reserve.size;
 946}
 947
 948/* sysfs device functions and data structures for CMO */
 949
 950#define viodev_cmo_rd_attr(name)                                        \
 951static ssize_t viodev_cmo_##name##_show(struct device *dev,             \
 952                                        struct device_attribute *attr,  \
 953                                         char *buf)                     \
 954{                                                                       \
 955	return sprintf(buf, "%lu\n", to_vio_dev(dev)->cmo.name);        \
 956}
 957
 958static ssize_t viodev_cmo_allocs_failed_show(struct device *dev,
 959		struct device_attribute *attr, char *buf)
 960{
 961	struct vio_dev *viodev = to_vio_dev(dev);
 962	return sprintf(buf, "%d\n", atomic_read(&viodev->cmo.allocs_failed));
 963}
 964
 965static ssize_t viodev_cmo_allocs_failed_reset(struct device *dev,
 966		struct device_attribute *attr, const char *buf, size_t count)
 967{
 968	struct vio_dev *viodev = to_vio_dev(dev);
 969	atomic_set(&viodev->cmo.allocs_failed, 0);
 970	return count;
 971}
 972
 973static ssize_t viodev_cmo_desired_set(struct device *dev,
 974		struct device_attribute *attr, const char *buf, size_t count)
 975{
 976	struct vio_dev *viodev = to_vio_dev(dev);
 977	size_t new_desired;
 978	int ret;
 979
 980	ret = kstrtoul(buf, 10, &new_desired);
 981	if (ret)
 982		return ret;
 983
 984	vio_cmo_set_dev_desired(viodev, new_desired);
 985	return count;
 986}
 987
 988viodev_cmo_rd_attr(desired);
 989viodev_cmo_rd_attr(entitled);
 990viodev_cmo_rd_attr(allocated);
 991
 992static ssize_t name_show(struct device *, struct device_attribute *, char *);
 993static ssize_t devspec_show(struct device *, struct device_attribute *, char *);
 994static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 995			     char *buf);
 996static struct device_attribute vio_cmo_dev_attrs[] = {
 997	__ATTR_RO(name),
 998	__ATTR_RO(devspec),
 999	__ATTR_RO(modalias),
1000	__ATTR(cmo_desired,       S_IWUSR|S_IRUSR|S_IWGRP|S_IRGRP|S_IROTH,
1001	       viodev_cmo_desired_show, viodev_cmo_desired_set),
1002	__ATTR(cmo_entitled,      S_IRUGO, viodev_cmo_entitled_show,      NULL),
1003	__ATTR(cmo_allocated,     S_IRUGO, viodev_cmo_allocated_show,     NULL),
1004	__ATTR(cmo_allocs_failed, S_IWUSR|S_IRUSR|S_IWGRP|S_IRGRP|S_IROTH,
1005	       viodev_cmo_allocs_failed_show, viodev_cmo_allocs_failed_reset),
1006	__ATTR_NULL
1007};
1008
1009/* sysfs bus functions and data structures for CMO */
1010
1011#define viobus_cmo_rd_attr(name)                                        \
1012static ssize_t cmo_##name##_show(struct bus_type *bt, char *buf)        \
1013{                                                                       \
1014	return sprintf(buf, "%lu\n", vio_cmo.name);                     \
1015}                                                                       \
1016static BUS_ATTR_RO(cmo_##name)
1017
1018#define viobus_cmo_pool_rd_attr(name, var)                              \
1019static ssize_t                                                          \
1020cmo_##name##_##var##_show(struct bus_type *bt, char *buf)               \
1021{                                                                       \
1022	return sprintf(buf, "%lu\n", vio_cmo.name.var);                 \
1023}                                                                       \
1024static BUS_ATTR_RO(cmo_##name##_##var)
1025
1026viobus_cmo_rd_attr(entitled);
1027viobus_cmo_rd_attr(spare);
1028viobus_cmo_rd_attr(min);
1029viobus_cmo_rd_attr(desired);
1030viobus_cmo_rd_attr(curr);
1031viobus_cmo_pool_rd_attr(reserve, size);
1032viobus_cmo_pool_rd_attr(excess, size);
1033viobus_cmo_pool_rd_attr(excess, free);
1034
1035static ssize_t cmo_high_show(struct bus_type *bt, char *buf)
1036{
1037	return sprintf(buf, "%lu\n", vio_cmo.high);
1038}
1039
1040static ssize_t cmo_high_store(struct bus_type *bt, const char *buf,
1041			      size_t count)
1042{
1043	unsigned long flags;
1044
1045	spin_lock_irqsave(&vio_cmo.lock, flags);
1046	vio_cmo.high = vio_cmo.curr;
1047	spin_unlock_irqrestore(&vio_cmo.lock, flags);
1048
1049	return count;
1050}
1051static BUS_ATTR_RW(cmo_high);
1052
1053static struct attribute *vio_bus_attrs[] = {
1054	&bus_attr_cmo_entitled.attr,
1055	&bus_attr_cmo_spare.attr,
1056	&bus_attr_cmo_min.attr,
1057	&bus_attr_cmo_desired.attr,
1058	&bus_attr_cmo_curr.attr,
1059	&bus_attr_cmo_high.attr,
1060	&bus_attr_cmo_reserve_size.attr,
1061	&bus_attr_cmo_excess_size.attr,
1062	&bus_attr_cmo_excess_free.attr,
1063	NULL,
1064};
1065ATTRIBUTE_GROUPS(vio_bus);
1066
1067static void vio_cmo_sysfs_init(void)
1068{
1069	vio_bus_type.dev_attrs = vio_cmo_dev_attrs;
1070	vio_bus_type.bus_groups = vio_bus_groups;
1071}
1072#else /* CONFIG_PPC_SMLPAR */
1073int vio_cmo_entitlement_update(size_t new_entitlement) { return 0; }
1074void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired) {}
1075static int vio_cmo_bus_probe(struct vio_dev *viodev) { return 0; }
1076static void vio_cmo_bus_remove(struct vio_dev *viodev) {}
1077static void vio_cmo_set_dma_ops(struct vio_dev *viodev) {}
1078static void vio_cmo_bus_init(void) {}
1079static void vio_cmo_sysfs_init(void) { }
1080#endif /* CONFIG_PPC_SMLPAR */
1081EXPORT_SYMBOL(vio_cmo_entitlement_update);
1082EXPORT_SYMBOL(vio_cmo_set_dev_desired);
1083
1084
1085/*
1086 * Platform Facilities Option (PFO) support
1087 */
1088
1089/**
1090 * vio_h_cop_sync - Perform a synchronous PFO co-processor operation
1091 *
1092 * @vdev - Pointer to a struct vio_dev for device
1093 * @op - Pointer to a struct vio_pfo_op for the operation parameters
1094 *
1095 * Calls the hypervisor to synchronously perform the PFO operation
1096 * described in @op.  In the case of a busy response from the hypervisor,
1097 * the operation will be re-submitted indefinitely unless a non-zero timeout
1098 * is specified or an error occurs. The timeout places a limit on when to
1099 * stop re-submitting a operation, the total time can be exceeded if an
1100 * operation is in progress.
1101 *
1102 * If op->hcall_ret is not NULL, this will be set to the return from the
1103 * last h_cop_op call or it will be 0 if an error not involving the h_call
1104 * was encountered.
1105 *
1106 * Returns:
1107 *	0 on success,
1108 *	-EINVAL if the h_call fails due to an invalid parameter,
1109 *	-E2BIG if the h_call can not be performed synchronously,
1110 *	-EBUSY if a timeout is specified and has elapsed,
1111 *	-EACCES if the memory area for data/status has been rescinded, or
1112 *	-EPERM if a hardware fault has been indicated
1113 */
1114int vio_h_cop_sync(struct vio_dev *vdev, struct vio_pfo_op *op)
1115{
1116	struct device *dev = &vdev->dev;
1117	unsigned long deadline = 0;
1118	long hret = 0;
1119	int ret = 0;
1120
1121	if (op->timeout)
1122		deadline = jiffies + msecs_to_jiffies(op->timeout);
1123
1124	while (true) {
1125		hret = plpar_hcall_norets(H_COP, op->flags,
1126				vdev->resource_id,
1127				op->in, op->inlen, op->out,
1128				op->outlen, op->csbcpb);
1129
1130		if (hret == H_SUCCESS ||
1131		    (hret != H_NOT_ENOUGH_RESOURCES &&
1132		     hret != H_BUSY && hret != H_RESOURCE) ||
1133		    (op->timeout && time_after(deadline, jiffies)))
1134			break;
1135
1136		dev_dbg(dev, "%s: hcall ret(%ld), retrying.\n", __func__, hret);
1137	}
1138
1139	switch (hret) {
1140	case H_SUCCESS:
1141		ret = 0;
1142		break;
1143	case H_OP_MODE:
1144	case H_TOO_BIG:
1145		ret = -E2BIG;
1146		break;
1147	case H_RESCINDED:
1148		ret = -EACCES;
1149		break;
1150	case H_HARDWARE:
1151		ret = -EPERM;
1152		break;
1153	case H_NOT_ENOUGH_RESOURCES:
1154	case H_RESOURCE:
1155	case H_BUSY:
1156		ret = -EBUSY;
1157		break;
1158	default:
1159		ret = -EINVAL;
1160		break;
1161	}
1162
1163	if (ret)
1164		dev_dbg(dev, "%s: Sync h_cop_op failure (ret:%d) (hret:%ld)\n",
1165				__func__, ret, hret);
1166
1167	op->hcall_err = hret;
1168	return ret;
1169}
1170EXPORT_SYMBOL(vio_h_cop_sync);
1171
1172static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev)
1173{
1174	const __be32 *dma_window;
1175	struct iommu_table *tbl;
1176	unsigned long offset, size;
1177
1178	dma_window = of_get_property(dev->dev.of_node,
1179				  "ibm,my-dma-window", NULL);
1180	if (!dma_window)
1181		return NULL;
1182
1183	tbl = kzalloc(sizeof(*tbl), GFP_KERNEL);
1184	if (tbl == NULL)
1185		return NULL;
1186
1187	of_parse_dma_window(dev->dev.of_node, dma_window,
1188			    &tbl->it_index, &offset, &size);
1189
1190	/* TCE table size - measured in tce entries */
1191	tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
1192	tbl->it_size = size >> tbl->it_page_shift;
1193	/* offset for VIO should always be 0 */
1194	tbl->it_offset = offset >> tbl->it_page_shift;
1195	tbl->it_busno = 0;
1196	tbl->it_type = TCE_VB;
1197	tbl->it_blocksize = 16;
1198
1199	if (firmware_has_feature(FW_FEATURE_LPAR))
1200		tbl->it_ops = &iommu_table_lpar_multi_ops;
1201	else
1202		tbl->it_ops = &iommu_table_pseries_ops;
1203
1204	return iommu_init_table(tbl, -1);
1205}
1206
1207/**
1208 * vio_match_device: - Tell if a VIO device has a matching
1209 *			VIO device id structure.
1210 * @ids:	array of VIO device id structures to search in
1211 * @dev:	the VIO device structure to match against
1212 *
1213 * Used by a driver to check whether a VIO device present in the
1214 * system is in its list of supported devices. Returns the matching
1215 * vio_device_id structure or NULL if there is no match.
1216 */
1217static const struct vio_device_id *vio_match_device(
1218		const struct vio_device_id *ids, const struct vio_dev *dev)
1219{
1220	while (ids->type[0] != '\0') {
1221		if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
1222		    of_device_is_compatible(dev->dev.of_node,
1223					 ids->compat))
1224			return ids;
1225		ids++;
1226	}
1227	return NULL;
1228}
1229
1230/*
1231 * Convert from struct device to struct vio_dev and pass to driver.
1232 * dev->driver has already been set by generic code because vio_bus_match
1233 * succeeded.
1234 */
1235static int vio_bus_probe(struct device *dev)
1236{
1237	struct vio_dev *viodev = to_vio_dev(dev);
1238	struct vio_driver *viodrv = to_vio_driver(dev->driver);
1239	const struct vio_device_id *id;
1240	int error = -ENODEV;
1241
1242	if (!viodrv->probe)
1243		return error;
1244
1245	id = vio_match_device(viodrv->id_table, viodev);
1246	if (id) {
1247		memset(&viodev->cmo, 0, sizeof(viodev->cmo));
1248		if (firmware_has_feature(FW_FEATURE_CMO)) {
1249			error = vio_cmo_bus_probe(viodev);
1250			if (error)
1251				return error;
1252		}
1253		error = viodrv->probe(viodev, id);
1254		if (error && firmware_has_feature(FW_FEATURE_CMO))
1255			vio_cmo_bus_remove(viodev);
1256	}
1257
1258	return error;
1259}
1260
1261/* convert from struct device to struct vio_dev and pass to driver. */
1262static int vio_bus_remove(struct device *dev)
1263{
1264	struct vio_dev *viodev = to_vio_dev(dev);
1265	struct vio_driver *viodrv = to_vio_driver(dev->driver);
1266	struct device *devptr;
1267	int ret = 1;
1268
1269	/*
1270	 * Hold a reference to the device after the remove function is called
1271	 * to allow for CMO accounting cleanup for the device.
1272	 */
1273	devptr = get_device(dev);
1274
1275	if (viodrv->remove)
1276		ret = viodrv->remove(viodev);
1277
1278	if (!ret && firmware_has_feature(FW_FEATURE_CMO))
1279		vio_cmo_bus_remove(viodev);
1280
1281	put_device(devptr);
1282	return ret;
1283}
1284
1285/**
1286 * vio_register_driver: - Register a new vio driver
1287 * @viodrv:	The vio_driver structure to be registered.
1288 */
1289int __vio_register_driver(struct vio_driver *viodrv, struct module *owner,
1290			  const char *mod_name)
1291{
1292	pr_debug("%s: driver %s registering\n", __func__, viodrv->name);
1293
1294	/* fill in 'struct driver' fields */
1295	viodrv->driver.name = viodrv->name;
1296	viodrv->driver.pm = viodrv->pm;
1297	viodrv->driver.bus = &vio_bus_type;
1298	viodrv->driver.owner = owner;
1299	viodrv->driver.mod_name = mod_name;
1300
1301	return driver_register(&viodrv->driver);
1302}
1303EXPORT_SYMBOL(__vio_register_driver);
1304
1305/**
1306 * vio_unregister_driver - Remove registration of vio driver.
1307 * @viodrv:	The vio_driver struct to be removed form registration
1308 */
1309void vio_unregister_driver(struct vio_driver *viodrv)
1310{
1311	driver_unregister(&viodrv->driver);
1312}
1313EXPORT_SYMBOL(vio_unregister_driver);
1314
1315/* vio_dev refcount hit 0 */
1316static void vio_dev_release(struct device *dev)
1317{
1318	struct iommu_table *tbl = get_iommu_table_base(dev);
1319
1320	if (tbl)
1321		iommu_free_table(tbl, of_node_full_name(dev->of_node));
1322	of_node_put(dev->of_node);
1323	kfree(to_vio_dev(dev));
1324}
1325
1326/**
1327 * vio_register_device_node: - Register a new vio device.
1328 * @of_node:	The OF node for this device.
1329 *
1330 * Creates and initializes a vio_dev structure from the data in
1331 * of_node and adds it to the list of virtual devices.
1332 * Returns a pointer to the created vio_dev or NULL if node has
1333 * NULL device_type or compatible fields.
1334 */
1335struct vio_dev *vio_register_device_node(struct device_node *of_node)
1336{
1337	struct vio_dev *viodev;
1338	struct device_node *parent_node;
1339	const __be32 *prop;
1340	enum vio_dev_family family;
1341	const char *of_node_name = of_node->name ? of_node->name : "<unknown>";
1342
1343	/*
1344	 * Determine if this node is a under the /vdevice node or under the
1345	 * /ibm,platform-facilities node.  This decides the device's family.
1346	 */
1347	parent_node = of_get_parent(of_node);
1348	if (parent_node) {
1349		if (!strcmp(parent_node->full_name, "/ibm,platform-facilities"))
1350			family = PFO;
1351		else if (!strcmp(parent_node->full_name, "/vdevice"))
1352			family = VDEVICE;
1353		else {
1354			pr_warn("%s: parent(%s) of %s not recognized.\n",
1355					__func__,
1356					parent_node->full_name,
1357					of_node_name);
1358			of_node_put(parent_node);
1359			return NULL;
1360		}
1361		of_node_put(parent_node);
1362	} else {
1363		pr_warn("%s: could not determine the parent of node %s.\n",
1364				__func__, of_node_name);
1365		return NULL;
1366	}
1367
1368	if (family == PFO) {
1369		if (of_get_property(of_node, "interrupt-controller", NULL)) {
1370			pr_debug("%s: Skipping the interrupt controller %s.\n",
1371					__func__, of_node_name);
1372			return NULL;
1373		}
1374	}
1375
1376	/* allocate a vio_dev for this node */
1377	viodev = kzalloc(sizeof(struct vio_dev), GFP_KERNEL);
1378	if (viodev == NULL) {
1379		pr_warn("%s: allocation failure for VIO device.\n", __func__);
1380		return NULL;
1381	}
1382
1383	/* we need the 'device_type' property, in order to match with drivers */
1384	viodev->family = family;
1385	if (viodev->family == VDEVICE) {
1386		unsigned int unit_address;
1387
1388		if (of_node->type != NULL)
1389			viodev->type = of_node->type;
1390		else {
1391			pr_warn("%s: node %s is missing the 'device_type' "
1392					"property.\n", __func__, of_node_name);
1393			goto out;
1394		}
1395
1396		prop = of_get_property(of_node, "reg", NULL);
1397		if (prop == NULL) {
1398			pr_warn("%s: node %s missing 'reg'\n",
1399					__func__, of_node_name);
1400			goto out;
1401		}
1402		unit_address = of_read_number(prop, 1);
1403		dev_set_name(&viodev->dev, "%x", unit_address);
1404		viodev->irq = irq_of_parse_and_map(of_node, 0);
1405		viodev->unit_address = unit_address;
1406	} else {
1407		/* PFO devices need their resource_id for submitting COP_OPs
1408		 * This is an optional field for devices, but is required when
1409		 * performing synchronous ops */
1410		prop = of_get_property(of_node, "ibm,resource-id", NULL);
1411		if (prop != NULL)
1412			viodev->resource_id = of_read_number(prop, 1);
1413
1414		dev_set_name(&viodev->dev, "%s", of_node_name);
1415		viodev->type = of_node_name;
1416		viodev->irq = 0;
1417	}
1418
1419	viodev->name = of_node->name;
1420	viodev->dev.of_node = of_node_get(of_node);
1421
1422	set_dev_node(&viodev->dev, of_node_to_nid(of_node));
1423
1424	/* init generic 'struct device' fields: */
1425	viodev->dev.parent = &vio_bus_device.dev;
1426	viodev->dev.bus = &vio_bus_type;
1427	viodev->dev.release = vio_dev_release;
1428
1429	if (of_get_property(viodev->dev.of_node, "ibm,my-dma-window", NULL)) {
1430		if (firmware_has_feature(FW_FEATURE_CMO))
1431			vio_cmo_set_dma_ops(viodev);
1432		else
1433			set_dma_ops(&viodev->dev, &dma_iommu_ops);
1434
1435		set_iommu_table_base(&viodev->dev,
1436				     vio_build_iommu_table(viodev));
1437
1438		/* needed to ensure proper operation of coherent allocations
1439		 * later, in case driver doesn't set it explicitly */
1440		viodev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
1441		viodev->dev.dma_mask = &viodev->dev.coherent_dma_mask;
1442	}
1443
1444	/* register with generic device framework */
1445	if (device_register(&viodev->dev)) {
1446		printk(KERN_ERR "%s: failed to register device %s\n",
1447				__func__, dev_name(&viodev->dev));
1448		put_device(&viodev->dev);
1449		return NULL;
1450	}
1451
1452	return viodev;
1453
1454out:	/* Use this exit point for any return prior to device_register */
1455	kfree(viodev);
1456
1457	return NULL;
1458}
1459EXPORT_SYMBOL(vio_register_device_node);
1460
1461/*
1462 * vio_bus_scan_for_devices - Scan OF and register each child device
1463 * @root_name - OF node name for the root of the subtree to search.
1464 *		This must be non-NULL
1465 *
1466 * Starting from the root node provide, register the device node for
1467 * each child beneath the root.
1468 */
1469static void vio_bus_scan_register_devices(char *root_name)
1470{
1471	struct device_node *node_root, *node_child;
1472
1473	if (!root_name)
1474		return;
1475
1476	node_root = of_find_node_by_name(NULL, root_name);
1477	if (node_root) {
1478
1479		/*
1480		 * Create struct vio_devices for each virtual device in
1481		 * the device tree. Drivers will associate with them later.
1482		 */
1483		node_child = of_get_next_child(node_root, NULL);
1484		while (node_child) {
1485			vio_register_device_node(node_child);
1486			node_child = of_get_next_child(node_root, node_child);
1487		}
1488		of_node_put(node_root);
1489	}
1490}
1491
1492/**
1493 * vio_bus_init: - Initialize the virtual IO bus
1494 */
1495static int __init vio_bus_init(void)
1496{
1497	int err;
1498
1499	if (firmware_has_feature(FW_FEATURE_CMO))
1500		vio_cmo_sysfs_init();
1501
1502	err = bus_register(&vio_bus_type);
1503	if (err) {
1504		printk(KERN_ERR "failed to register VIO bus\n");
1505		return err;
1506	}
1507
1508	/*
1509	 * The fake parent of all vio devices, just to give us
1510	 * a nice directory
1511	 */
1512	err = device_register(&vio_bus_device.dev);
1513	if (err) {
1514		printk(KERN_WARNING "%s: device_register returned %i\n",
1515				__func__, err);
1516		return err;
1517	}
1518
1519	if (firmware_has_feature(FW_FEATURE_CMO))
1520		vio_cmo_bus_init();
1521
1522	return 0;
1523}
1524postcore_initcall(vio_bus_init);
1525
1526static int __init vio_device_init(void)
1527{
1528	vio_bus_scan_register_devices("vdevice");
1529	vio_bus_scan_register_devices("ibm,platform-facilities");
1530
1531	return 0;
1532}
1533device_initcall(vio_device_init);
1534
1535static ssize_t name_show(struct device *dev,
1536		struct device_attribute *attr, char *buf)
1537{
1538	return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
1539}
1540
1541static ssize_t devspec_show(struct device *dev,
1542		struct device_attribute *attr, char *buf)
1543{
1544	struct device_node *of_node = dev->of_node;
1545
1546	return sprintf(buf, "%s\n", of_node_full_name(of_node));
1547}
1548
1549static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
1550			     char *buf)
1551{
1552	const struct vio_dev *vio_dev = to_vio_dev(dev);
1553	struct device_node *dn;
1554	const char *cp;
1555
1556	dn = dev->of_node;
1557	if (!dn) {
1558		strcpy(buf, "\n");
1559		return strlen(buf);
1560	}
1561	cp = of_get_property(dn, "compatible", NULL);
1562	if (!cp) {
1563		strcpy(buf, "\n");
1564		return strlen(buf);
1565	}
1566
1567	return sprintf(buf, "vio:T%sS%s\n", vio_dev->type, cp);
1568}
1569
1570static struct device_attribute vio_dev_attrs[] = {
1571	__ATTR_RO(name),
1572	__ATTR_RO(devspec),
1573	__ATTR_RO(modalias),
1574	__ATTR_NULL
1575};
1576
1577void vio_unregister_device(struct vio_dev *viodev)
1578{
1579	device_unregister(&viodev->dev);
1580}
1581EXPORT_SYMBOL(vio_unregister_device);
1582
1583static int vio_bus_match(struct device *dev, struct device_driver *drv)
1584{
1585	const struct vio_dev *vio_dev = to_vio_dev(dev);
1586	struct vio_driver *vio_drv = to_vio_driver(drv);
1587	const struct vio_device_id *ids = vio_drv->id_table;
1588
1589	return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
1590}
1591
1592static int vio_hotplug(struct device *dev, struct kobj_uevent_env *env)
1593{
1594	const struct vio_dev *vio_dev = to_vio_dev(dev);
1595	struct device_node *dn;
1596	const char *cp;
1597
1598	dn = dev->of_node;
1599	if (!dn)
1600		return -ENODEV;
1601	cp = of_get_property(dn, "compatible", NULL);
1602	if (!cp)
1603		return -ENODEV;
1604
1605	add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, cp);
1606	return 0;
1607}
1608
1609struct bus_type vio_bus_type = {
1610	.name = "vio",
1611	.dev_attrs = vio_dev_attrs,
1612	.uevent = vio_hotplug,
1613	.match = vio_bus_match,
1614	.probe = vio_bus_probe,
1615	.remove = vio_bus_remove,
1616};
1617
1618/**
1619 * vio_get_attribute: - get attribute for virtual device
1620 * @vdev:	The vio device to get property.
1621 * @which:	The property/attribute to be extracted.
1622 * @length:	Pointer to length of returned data size (unused if NULL).
1623 *
1624 * Calls prom.c's of_get_property() to return the value of the
1625 * attribute specified by @which
1626*/
1627const void *vio_get_attribute(struct vio_dev *vdev, char *which, int *length)
1628{
1629	return of_get_property(vdev->dev.of_node, which, length);
1630}
1631EXPORT_SYMBOL(vio_get_attribute);
1632
1633#ifdef CONFIG_PPC_PSERIES
1634/* vio_find_name() - internal because only vio.c knows how we formatted the
1635 * kobject name
1636 */
1637static struct vio_dev *vio_find_name(const char *name)
1638{
1639	struct device *found;
1640
1641	found = bus_find_device_by_name(&vio_bus_type, NULL, name);
1642	if (!found)
1643		return NULL;
1644
1645	return to_vio_dev(found);
1646}
1647
1648/**
1649 * vio_find_node - find an already-registered vio_dev
1650 * @vnode: device_node of the virtual device we're looking for
1651 */
1652struct vio_dev *vio_find_node(struct device_node *vnode)
1653{
1654	char kobj_name[20];
1655	struct device_node *vnode_parent;
1656	const char *dev_type;
1657
1658	vnode_parent = of_get_parent(vnode);
1659	if (!vnode_parent)
1660		return NULL;
1661
1662	dev_type = of_get_property(vnode_parent, "device_type", NULL);
1663	of_node_put(vnode_parent);
1664	if (!dev_type)
1665		return NULL;
1666
1667	/* construct the kobject name from the device node */
1668	if (!strcmp(dev_type, "vdevice")) {
1669		const __be32 *prop;
1670		
1671		prop = of_get_property(vnode, "reg", NULL);
1672		if (!prop)
1673			return NULL;
1674		snprintf(kobj_name, sizeof(kobj_name), "%x",
1675			 (uint32_t)of_read_number(prop, 1));
1676	} else if (!strcmp(dev_type, "ibm,platform-facilities"))
1677		snprintf(kobj_name, sizeof(kobj_name), "%s", vnode->name);
1678	else
1679		return NULL;
1680
1681	return vio_find_name(kobj_name);
1682}
1683EXPORT_SYMBOL(vio_find_node);
1684
1685int vio_enable_interrupts(struct vio_dev *dev)
1686{
1687	int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
1688	if (rc != H_SUCCESS)
1689		printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
1690	return rc;
1691}
1692EXPORT_SYMBOL(vio_enable_interrupts);
1693
1694int vio_disable_interrupts(struct vio_dev *dev)
1695{
1696	int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
1697	if (rc != H_SUCCESS)
1698		printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
1699	return rc;
1700}
1701EXPORT_SYMBOL(vio_disable_interrupts);
1702#endif /* CONFIG_PPC_PSERIES */