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v4.6
   1/*
   2 * Copyright 2011 (c) Oracle Corp.
   3
   4 * Permission is hereby granted, free of charge, to any person obtaining a
   5 * copy of this software and associated documentation files (the "Software"),
   6 * to deal in the Software without restriction, including without limitation
   7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8 * and/or sell copies of the Software, and to permit persons to whom the
   9 * Software is furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice (including the
  12 * next paragraph) shall be included in all copies or substantial portions
  13 * of the Software.
  14 *
  15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21 * DEALINGS IN THE SOFTWARE.
  22 *
  23 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
  24 */
  25
  26/*
  27 * A simple DMA pool losely based on dmapool.c. It has certain advantages
  28 * over the DMA pools:
  29 * - Pool collects resently freed pages for reuse (and hooks up to
  30 *   the shrinker).
  31 * - Tracks currently in use pages
  32 * - Tracks whether the page is UC, WB or cached (and reverts to WB
  33 *   when freed).
  34 */
  35
  36#if defined(CONFIG_SWIOTLB) || defined(CONFIG_INTEL_IOMMU)
  37#define pr_fmt(fmt) "[TTM] " fmt
  38
  39#include <linux/dma-mapping.h>
  40#include <linux/list.h>
  41#include <linux/seq_file.h> /* for seq_printf */
  42#include <linux/slab.h>
  43#include <linux/spinlock.h>
  44#include <linux/highmem.h>
  45#include <linux/mm_types.h>
  46#include <linux/module.h>
  47#include <linux/mm.h>
  48#include <linux/atomic.h>
  49#include <linux/device.h>
  50#include <linux/kthread.h>
  51#include <drm/ttm/ttm_bo_driver.h>
  52#include <drm/ttm/ttm_page_alloc.h>
  53#ifdef TTM_HAS_AGP
  54#include <asm/agp.h>
  55#endif
  56
  57#define NUM_PAGES_TO_ALLOC		(PAGE_SIZE/sizeof(struct page *))
  58#define SMALL_ALLOCATION		4
  59#define FREE_ALL_PAGES			(~0U)
  60/* times are in msecs */
  61#define IS_UNDEFINED			(0)
  62#define IS_WC				(1<<1)
  63#define IS_UC				(1<<2)
  64#define IS_CACHED			(1<<3)
  65#define IS_DMA32			(1<<4)
  66
  67enum pool_type {
  68	POOL_IS_UNDEFINED,
  69	POOL_IS_WC = IS_WC,
  70	POOL_IS_UC = IS_UC,
  71	POOL_IS_CACHED = IS_CACHED,
  72	POOL_IS_WC_DMA32 = IS_WC | IS_DMA32,
  73	POOL_IS_UC_DMA32 = IS_UC | IS_DMA32,
  74	POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32,
  75};
 
  76/*
  77 * The pool structure. There are usually six pools:
  78 *  - generic (not restricted to DMA32):
  79 *      - write combined, uncached, cached.
  80 *  - dma32 (up to 2^32 - so up 4GB):
  81 *      - write combined, uncached, cached.
 
 
  82 * for each 'struct device'. The 'cached' is for pages that are actively used.
  83 * The other ones can be shrunk by the shrinker API if neccessary.
  84 * @pools: The 'struct device->dma_pools' link.
  85 * @type: Type of the pool
  86 * @lock: Protects the inuse_list and free_list from concurrnet access. Must be
  87 * used with irqsave/irqrestore variants because pool allocator maybe called
  88 * from delayed work.
  89 * @inuse_list: Pool of pages that are in use. The order is very important and
  90 *   it is in the order that the TTM pages that are put back are in.
  91 * @free_list: Pool of pages that are free to be used. No order requirements.
  92 * @dev: The device that is associated with these pools.
  93 * @size: Size used during DMA allocation.
  94 * @npages_free: Count of available pages for re-use.
  95 * @npages_in_use: Count of pages that are in use.
  96 * @nfrees: Stats when pool is shrinking.
  97 * @nrefills: Stats when the pool is grown.
  98 * @gfp_flags: Flags to pass for alloc_page.
  99 * @name: Name of the pool.
 100 * @dev_name: Name derieved from dev - similar to how dev_info works.
 101 *   Used during shutdown as the dev_info during release is unavailable.
 102 */
 103struct dma_pool {
 104	struct list_head pools; /* The 'struct device->dma_pools link */
 105	enum pool_type type;
 106	spinlock_t lock;
 107	struct list_head inuse_list;
 108	struct list_head free_list;
 109	struct device *dev;
 110	unsigned size;
 111	unsigned npages_free;
 112	unsigned npages_in_use;
 113	unsigned long nfrees; /* Stats when shrunk. */
 114	unsigned long nrefills; /* Stats when grown. */
 115	gfp_t gfp_flags;
 116	char name[13]; /* "cached dma32" */
 117	char dev_name[64]; /* Constructed from dev */
 118};
 119
 120/*
 121 * The accounting page keeping track of the allocated page along with
 122 * the DMA address.
 123 * @page_list: The link to the 'page_list' in 'struct dma_pool'.
 124 * @vaddr: The virtual address of the page
 
 125 * @dma: The bus address of the page. If the page is not allocated
 126 *   via the DMA API, it will be -1.
 127 */
 128struct dma_page {
 129	struct list_head page_list;
 130	void *vaddr;
 131	struct page *p;
 132	dma_addr_t dma;
 133};
 134
 135/*
 136 * Limits for the pool. They are handled without locks because only place where
 137 * they may change is in sysfs store. They won't have immediate effect anyway
 138 * so forcing serialization to access them is pointless.
 139 */
 140
 141struct ttm_pool_opts {
 142	unsigned	alloc_size;
 143	unsigned	max_size;
 144	unsigned	small;
 145};
 146
 147/*
 148 * Contains the list of all of the 'struct device' and their corresponding
 149 * DMA pools. Guarded by _mutex->lock.
 150 * @pools: The link to 'struct ttm_pool_manager->pools'
 151 * @dev: The 'struct device' associated with the 'pool'
 152 * @pool: The 'struct dma_pool' associated with the 'dev'
 153 */
 154struct device_pools {
 155	struct list_head pools;
 156	struct device *dev;
 157	struct dma_pool *pool;
 158};
 159
 160/*
 161 * struct ttm_pool_manager - Holds memory pools for fast allocation
 162 *
 163 * @lock: Lock used when adding/removing from pools
 164 * @pools: List of 'struct device' and 'struct dma_pool' tuples.
 165 * @options: Limits for the pool.
 166 * @npools: Total amount of pools in existence.
 167 * @shrinker: The structure used by [un|]register_shrinker
 168 */
 169struct ttm_pool_manager {
 170	struct mutex		lock;
 171	struct list_head	pools;
 172	struct ttm_pool_opts	options;
 173	unsigned		npools;
 174	struct shrinker		mm_shrink;
 175	struct kobject		kobj;
 176};
 177
 178static struct ttm_pool_manager *_manager;
 179
 180static struct attribute ttm_page_pool_max = {
 181	.name = "pool_max_size",
 182	.mode = S_IRUGO | S_IWUSR
 183};
 184static struct attribute ttm_page_pool_small = {
 185	.name = "pool_small_allocation",
 186	.mode = S_IRUGO | S_IWUSR
 187};
 188static struct attribute ttm_page_pool_alloc_size = {
 189	.name = "pool_allocation_size",
 190	.mode = S_IRUGO | S_IWUSR
 191};
 192
 193static struct attribute *ttm_pool_attrs[] = {
 194	&ttm_page_pool_max,
 195	&ttm_page_pool_small,
 196	&ttm_page_pool_alloc_size,
 197	NULL
 198};
 199
 200static void ttm_pool_kobj_release(struct kobject *kobj)
 201{
 202	struct ttm_pool_manager *m =
 203		container_of(kobj, struct ttm_pool_manager, kobj);
 204	kfree(m);
 205}
 206
 207static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
 208			      const char *buffer, size_t size)
 209{
 210	struct ttm_pool_manager *m =
 211		container_of(kobj, struct ttm_pool_manager, kobj);
 212	int chars;
 213	unsigned val;
 
 214	chars = sscanf(buffer, "%u", &val);
 215	if (chars == 0)
 216		return size;
 217
 218	/* Convert kb to number of pages */
 219	val = val / (PAGE_SIZE >> 10);
 220
 221	if (attr == &ttm_page_pool_max)
 222		m->options.max_size = val;
 223	else if (attr == &ttm_page_pool_small)
 224		m->options.small = val;
 225	else if (attr == &ttm_page_pool_alloc_size) {
 226		if (val > NUM_PAGES_TO_ALLOC*8) {
 227			pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 228			       NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 229			       NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 230			return size;
 231		} else if (val > NUM_PAGES_TO_ALLOC) {
 232			pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 233				NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 234		}
 235		m->options.alloc_size = val;
 236	}
 237
 238	return size;
 239}
 240
 241static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
 242			     char *buffer)
 243{
 244	struct ttm_pool_manager *m =
 245		container_of(kobj, struct ttm_pool_manager, kobj);
 246	unsigned val = 0;
 247
 248	if (attr == &ttm_page_pool_max)
 249		val = m->options.max_size;
 250	else if (attr == &ttm_page_pool_small)
 251		val = m->options.small;
 252	else if (attr == &ttm_page_pool_alloc_size)
 253		val = m->options.alloc_size;
 254
 255	val = val * (PAGE_SIZE >> 10);
 256
 257	return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 258}
 259
 260static const struct sysfs_ops ttm_pool_sysfs_ops = {
 261	.show = &ttm_pool_show,
 262	.store = &ttm_pool_store,
 263};
 264
 265static struct kobj_type ttm_pool_kobj_type = {
 266	.release = &ttm_pool_kobj_release,
 267	.sysfs_ops = &ttm_pool_sysfs_ops,
 268	.default_attrs = ttm_pool_attrs,
 269};
 270
 271#ifndef CONFIG_X86
 272static int set_pages_array_wb(struct page **pages, int addrinarray)
 273{
 274#ifdef TTM_HAS_AGP
 275	int i;
 276
 277	for (i = 0; i < addrinarray; i++)
 278		unmap_page_from_agp(pages[i]);
 279#endif
 280	return 0;
 281}
 282
 283static int set_pages_array_wc(struct page **pages, int addrinarray)
 284{
 285#ifdef TTM_HAS_AGP
 286	int i;
 287
 288	for (i = 0; i < addrinarray; i++)
 289		map_page_into_agp(pages[i]);
 290#endif
 291	return 0;
 292}
 293
 294static int set_pages_array_uc(struct page **pages, int addrinarray)
 295{
 296#ifdef TTM_HAS_AGP
 297	int i;
 298
 299	for (i = 0; i < addrinarray; i++)
 300		map_page_into_agp(pages[i]);
 301#endif
 302	return 0;
 303}
 304#endif /* for !CONFIG_X86 */
 305
 306static int ttm_set_pages_caching(struct dma_pool *pool,
 307				 struct page **pages, unsigned cpages)
 308{
 309	int r = 0;
 310	/* Set page caching */
 311	if (pool->type & IS_UC) {
 312		r = set_pages_array_uc(pages, cpages);
 313		if (r)
 314			pr_err("%s: Failed to set %d pages to uc!\n",
 315			       pool->dev_name, cpages);
 316	}
 317	if (pool->type & IS_WC) {
 318		r = set_pages_array_wc(pages, cpages);
 319		if (r)
 320			pr_err("%s: Failed to set %d pages to wc!\n",
 321			       pool->dev_name, cpages);
 322	}
 323	return r;
 324}
 325
 326static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
 327{
 
 328	dma_addr_t dma = d_page->dma;
 329	dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma);
 
 
 
 
 330
 331	kfree(d_page);
 332	d_page = NULL;
 333}
 334static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
 335{
 336	struct dma_page *d_page;
 
 
 337
 338	d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
 339	if (!d_page)
 340		return NULL;
 341
 342	d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
 343					   &d_page->dma,
 344					   pool->gfp_flags);
 345	if (d_page->vaddr) {
 346		if (is_vmalloc_addr(d_page->vaddr))
 347			d_page->p = vmalloc_to_page(d_page->vaddr);
 
 
 348		else
 349			d_page->p = virt_to_page(d_page->vaddr);
 
 
 
 350	} else {
 351		kfree(d_page);
 352		d_page = NULL;
 353	}
 354	return d_page;
 355}
 356static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
 357{
 358	enum pool_type type = IS_UNDEFINED;
 359
 360	if (flags & TTM_PAGE_FLAG_DMA32)
 361		type |= IS_DMA32;
 362	if (cstate == tt_cached)
 363		type |= IS_CACHED;
 364	else if (cstate == tt_uncached)
 365		type |= IS_UC;
 366	else
 367		type |= IS_WC;
 368
 369	return type;
 370}
 371
 372static void ttm_pool_update_free_locked(struct dma_pool *pool,
 373					unsigned freed_pages)
 374{
 375	pool->npages_free -= freed_pages;
 376	pool->nfrees += freed_pages;
 377
 378}
 379
 380/* set memory back to wb and free the pages. */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 381static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
 382			      struct page *pages[], unsigned npages)
 383{
 384	struct dma_page *d_page, *tmp;
 385
 
 
 
 
 
 
 
 386	/* Don't set WB on WB page pool. */
 387	if (npages && !(pool->type & IS_CACHED) &&
 388	    set_pages_array_wb(pages, npages))
 389		pr_err("%s: Failed to set %d pages to wb!\n",
 390		       pool->dev_name, npages);
 391
 392	list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 393		list_del(&d_page->page_list);
 394		__ttm_dma_free_page(pool, d_page);
 395	}
 396}
 397
 398static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
 399{
 400	/* Don't set WB on WB page pool. */
 401	if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1))
 402		pr_err("%s: Failed to set %d pages to wb!\n",
 403		       pool->dev_name, 1);
 404
 405	list_del(&d_page->page_list);
 406	__ttm_dma_free_page(pool, d_page);
 407}
 408
 409/*
 410 * Free pages from pool.
 411 *
 412 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 413 * number of pages in one go.
 414 *
 415 * @pool: to free the pages from
 416 * @nr_free: If set to true will free all pages in pool
 417 * @use_static: Safe to use static buffer
 418 **/
 419static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
 420				       bool use_static)
 421{
 422	static struct page *static_buf[NUM_PAGES_TO_ALLOC];
 423	unsigned long irq_flags;
 424	struct dma_page *dma_p, *tmp;
 425	struct page **pages_to_free;
 426	struct list_head d_pages;
 427	unsigned freed_pages = 0,
 428		 npages_to_free = nr_free;
 429
 430	if (NUM_PAGES_TO_ALLOC < nr_free)
 431		npages_to_free = NUM_PAGES_TO_ALLOC;
 432#if 0
 433	if (nr_free > 1) {
 434		pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
 435			 pool->dev_name, pool->name, current->pid,
 436			 npages_to_free, nr_free);
 437	}
 438#endif
 439	if (use_static)
 440		pages_to_free = static_buf;
 441	else
 442		pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
 443					GFP_KERNEL);
 
 444
 445	if (!pages_to_free) {
 446		pr_err("%s: Failed to allocate memory for pool free operation\n",
 447		       pool->dev_name);
 448		return 0;
 449	}
 450	INIT_LIST_HEAD(&d_pages);
 451restart:
 452	spin_lock_irqsave(&pool->lock, irq_flags);
 453
 454	/* We picking the oldest ones off the list */
 455	list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
 456					 page_list) {
 457		if (freed_pages >= npages_to_free)
 458			break;
 459
 460		/* Move the dma_page from one list to another. */
 461		list_move(&dma_p->page_list, &d_pages);
 462
 463		pages_to_free[freed_pages++] = dma_p->p;
 464		/* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 465		if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 466
 467			ttm_pool_update_free_locked(pool, freed_pages);
 468			/**
 469			 * Because changing page caching is costly
 470			 * we unlock the pool to prevent stalling.
 471			 */
 472			spin_unlock_irqrestore(&pool->lock, irq_flags);
 473
 474			ttm_dma_pages_put(pool, &d_pages, pages_to_free,
 475					  freed_pages);
 476
 477			INIT_LIST_HEAD(&d_pages);
 478
 479			if (likely(nr_free != FREE_ALL_PAGES))
 480				nr_free -= freed_pages;
 481
 482			if (NUM_PAGES_TO_ALLOC >= nr_free)
 483				npages_to_free = nr_free;
 484			else
 485				npages_to_free = NUM_PAGES_TO_ALLOC;
 486
 487			freed_pages = 0;
 488
 489			/* free all so restart the processing */
 490			if (nr_free)
 491				goto restart;
 492
 493			/* Not allowed to fall through or break because
 494			 * following context is inside spinlock while we are
 495			 * outside here.
 496			 */
 497			goto out;
 498
 499		}
 500	}
 501
 502	/* remove range of pages from the pool */
 503	if (freed_pages) {
 504		ttm_pool_update_free_locked(pool, freed_pages);
 505		nr_free -= freed_pages;
 506	}
 507
 508	spin_unlock_irqrestore(&pool->lock, irq_flags);
 509
 510	if (freed_pages)
 511		ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
 512out:
 513	if (pages_to_free != static_buf)
 514		kfree(pages_to_free);
 515	return nr_free;
 516}
 517
 518static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
 519{
 520	struct device_pools *p;
 521	struct dma_pool *pool;
 522
 523	if (!dev)
 524		return;
 525
 526	mutex_lock(&_manager->lock);
 527	list_for_each_entry_reverse(p, &_manager->pools, pools) {
 528		if (p->dev != dev)
 529			continue;
 530		pool = p->pool;
 531		if (pool->type != type)
 532			continue;
 533
 534		list_del(&p->pools);
 535		kfree(p);
 536		_manager->npools--;
 537		break;
 538	}
 539	list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
 540		if (pool->type != type)
 541			continue;
 542		/* Takes a spinlock.. */
 543		/* OK to use static buffer since global mutex is held. */
 544		ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, true);
 545		WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
 546		/* This code path is called after _all_ references to the
 547		 * struct device has been dropped - so nobody should be
 548		 * touching it. In case somebody is trying to _add_ we are
 549		 * guarded by the mutex. */
 550		list_del(&pool->pools);
 551		kfree(pool);
 552		break;
 553	}
 554	mutex_unlock(&_manager->lock);
 555}
 556
 557/*
 558 * On free-ing of the 'struct device' this deconstructor is run.
 559 * Albeit the pool might have already been freed earlier.
 560 */
 561static void ttm_dma_pool_release(struct device *dev, void *res)
 562{
 563	struct dma_pool *pool = *(struct dma_pool **)res;
 564
 565	if (pool)
 566		ttm_dma_free_pool(dev, pool->type);
 567}
 568
 569static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
 570{
 571	return *(struct dma_pool **)res == match_data;
 572}
 573
 574static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
 575					  enum pool_type type)
 576{
 577	char *n[] = {"wc", "uc", "cached", " dma32", "unknown",};
 578	enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED};
 579	struct device_pools *sec_pool = NULL;
 580	struct dma_pool *pool = NULL, **ptr;
 581	unsigned i;
 582	int ret = -ENODEV;
 583	char *p;
 584
 585	if (!dev)
 586		return NULL;
 587
 588	ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
 589	if (!ptr)
 590		return NULL;
 591
 592	ret = -ENOMEM;
 593
 594	pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
 595			    dev_to_node(dev));
 596	if (!pool)
 597		goto err_mem;
 598
 599	sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
 600				dev_to_node(dev));
 601	if (!sec_pool)
 602		goto err_mem;
 603
 604	INIT_LIST_HEAD(&sec_pool->pools);
 605	sec_pool->dev = dev;
 606	sec_pool->pool =  pool;
 607
 608	INIT_LIST_HEAD(&pool->free_list);
 609	INIT_LIST_HEAD(&pool->inuse_list);
 610	INIT_LIST_HEAD(&pool->pools);
 611	spin_lock_init(&pool->lock);
 612	pool->dev = dev;
 613	pool->npages_free = pool->npages_in_use = 0;
 614	pool->nfrees = 0;
 615	pool->gfp_flags = flags;
 616	pool->size = PAGE_SIZE;
 
 
 
 
 
 
 
 617	pool->type = type;
 618	pool->nrefills = 0;
 619	p = pool->name;
 620	for (i = 0; i < 5; i++) {
 621		if (type & t[i]) {
 622			p += snprintf(p, sizeof(pool->name) - (p - pool->name),
 623				      "%s", n[i]);
 624		}
 625	}
 626	*p = 0;
 627	/* We copy the name for pr_ calls b/c when dma_pool_destroy is called
 628	 * - the kobj->name has already been deallocated.*/
 629	snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
 630		 dev_driver_string(dev), dev_name(dev));
 631	mutex_lock(&_manager->lock);
 632	/* You can get the dma_pool from either the global: */
 633	list_add(&sec_pool->pools, &_manager->pools);
 634	_manager->npools++;
 635	/* or from 'struct device': */
 636	list_add(&pool->pools, &dev->dma_pools);
 637	mutex_unlock(&_manager->lock);
 638
 639	*ptr = pool;
 640	devres_add(dev, ptr);
 641
 642	return pool;
 643err_mem:
 644	devres_free(ptr);
 645	kfree(sec_pool);
 646	kfree(pool);
 647	return ERR_PTR(ret);
 648}
 649
 650static struct dma_pool *ttm_dma_find_pool(struct device *dev,
 651					  enum pool_type type)
 652{
 653	struct dma_pool *pool, *tmp, *found = NULL;
 654
 655	if (type == IS_UNDEFINED)
 656		return found;
 657
 658	/* NB: We iterate on the 'struct dev' which has no spinlock, but
 659	 * it does have a kref which we have taken. The kref is taken during
 660	 * graphic driver loading - in the drm_pci_init it calls either
 661	 * pci_dev_get or pci_register_driver which both end up taking a kref
 662	 * on 'struct device'.
 663	 *
 664	 * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
 665	 * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
 666	 * thing is at that point of time there are no pages associated with the
 667	 * driver so this function will not be called.
 668	 */
 669	list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) {
 670		if (pool->type != type)
 671			continue;
 672		found = pool;
 673		break;
 674	}
 675	return found;
 676}
 677
 678/*
 679 * Free pages the pages that failed to change the caching state. If there
 680 * are pages that have changed their caching state already put them to the
 681 * pool.
 682 */
 683static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
 684						 struct list_head *d_pages,
 685						 struct page **failed_pages,
 686						 unsigned cpages)
 687{
 688	struct dma_page *d_page, *tmp;
 689	struct page *p;
 690	unsigned i = 0;
 691
 692	p = failed_pages[0];
 693	if (!p)
 694		return;
 695	/* Find the failed page. */
 696	list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 697		if (d_page->p != p)
 698			continue;
 699		/* .. and then progress over the full list. */
 700		list_del(&d_page->page_list);
 701		__ttm_dma_free_page(pool, d_page);
 702		if (++i < cpages)
 703			p = failed_pages[i];
 704		else
 705			break;
 706	}
 707
 708}
 709
 710/*
 711 * Allocate 'count' pages, and put 'need' number of them on the
 712 * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
 713 * The full list of pages should also be on 'd_pages'.
 714 * We return zero for success, and negative numbers as errors.
 715 */
 716static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
 717					struct list_head *d_pages,
 718					unsigned count)
 719{
 720	struct page **caching_array;
 721	struct dma_page *dma_p;
 722	struct page *p;
 723	int r = 0;
 724	unsigned i, cpages;
 725	unsigned max_cpages = min(count,
 726			(unsigned)(PAGE_SIZE/sizeof(struct page *)));
 727
 728	/* allocate array for page caching change */
 729	caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
 
 730
 731	if (!caching_array) {
 732		pr_err("%s: Unable to allocate table for new pages\n",
 733		       pool->dev_name);
 734		return -ENOMEM;
 735	}
 736
 737	if (count > 1) {
 738		pr_debug("%s: (%s:%d) Getting %d pages\n",
 739			 pool->dev_name, pool->name, current->pid, count);
 740	}
 741
 742	for (i = 0, cpages = 0; i < count; ++i) {
 743		dma_p = __ttm_dma_alloc_page(pool);
 744		if (!dma_p) {
 745			pr_err("%s: Unable to get page %u\n",
 746			       pool->dev_name, i);
 747
 748			/* store already allocated pages in the pool after
 749			 * setting the caching state */
 750			if (cpages) {
 751				r = ttm_set_pages_caching(pool, caching_array,
 752							  cpages);
 753				if (r)
 754					ttm_dma_handle_caching_state_failure(
 755						pool, d_pages, caching_array,
 756						cpages);
 757			}
 758			r = -ENOMEM;
 759			goto out;
 760		}
 761		p = dma_p->p;
 
 
 762#ifdef CONFIG_HIGHMEM
 763		/* gfp flags of highmem page should never be dma32 so we
 764		 * we should be fine in such case
 765		 */
 766		if (!PageHighMem(p))
 
 767#endif
 768		{
 769			caching_array[cpages++] = p;
 
 
 770			if (cpages == max_cpages) {
 771				/* Note: Cannot hold the spinlock */
 772				r = ttm_set_pages_caching(pool, caching_array,
 773						 cpages);
 774				if (r) {
 775					ttm_dma_handle_caching_state_failure(
 776						pool, d_pages, caching_array,
 777						cpages);
 778					goto out;
 779				}
 780				cpages = 0;
 781			}
 782		}
 783		list_add(&dma_p->page_list, d_pages);
 784	}
 785
 786	if (cpages) {
 787		r = ttm_set_pages_caching(pool, caching_array, cpages);
 788		if (r)
 789			ttm_dma_handle_caching_state_failure(pool, d_pages,
 790					caching_array, cpages);
 791	}
 792out:
 793	kfree(caching_array);
 794	return r;
 795}
 796
 797/*
 798 * @return count of pages still required to fulfill the request.
 799 */
 800static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
 801					 unsigned long *irq_flags)
 802{
 803	unsigned count = _manager->options.small;
 804	int r = pool->npages_free;
 805
 806	if (count > pool->npages_free) {
 807		struct list_head d_pages;
 808
 809		INIT_LIST_HEAD(&d_pages);
 810
 811		spin_unlock_irqrestore(&pool->lock, *irq_flags);
 812
 813		/* Returns how many more are neccessary to fulfill the
 814		 * request. */
 815		r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
 816
 817		spin_lock_irqsave(&pool->lock, *irq_flags);
 818		if (!r) {
 819			/* Add the fresh to the end.. */
 820			list_splice(&d_pages, &pool->free_list);
 821			++pool->nrefills;
 822			pool->npages_free += count;
 823			r = count;
 824		} else {
 825			struct dma_page *d_page;
 826			unsigned cpages = 0;
 827
 828			pr_err("%s: Failed to fill %s pool (r:%d)!\n",
 829			       pool->dev_name, pool->name, r);
 830
 831			list_for_each_entry(d_page, &d_pages, page_list) {
 832				cpages++;
 833			}
 834			list_splice_tail(&d_pages, &pool->free_list);
 835			pool->npages_free += cpages;
 836			r = cpages;
 837		}
 838	}
 839	return r;
 840}
 841
 842/*
 843 * @return count of pages still required to fulfill the request.
 844 * The populate list is actually a stack (not that is matters as TTM
 845 * allocates one page at a time.
 
 846 */
 847static int ttm_dma_pool_get_pages(struct dma_pool *pool,
 848				  struct ttm_dma_tt *ttm_dma,
 849				  unsigned index)
 850{
 851	struct dma_page *d_page;
 852	struct ttm_tt *ttm = &ttm_dma->ttm;
 853	unsigned long irq_flags;
 854	int count, r = -ENOMEM;
 855
 856	spin_lock_irqsave(&pool->lock, irq_flags);
 857	count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
 858	if (count) {
 859		d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
 860		ttm->pages[index] = d_page->p;
 861		ttm_dma->cpu_address[index] = d_page->vaddr;
 862		ttm_dma->dma_address[index] = d_page->dma;
 863		list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
 864		r = 0;
 865		pool->npages_in_use += 1;
 866		pool->npages_free -= 1;
 867	}
 868	spin_unlock_irqrestore(&pool->lock, irq_flags);
 869	return r;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 870}
 871
 872/*
 873 * On success pages list will hold count number of correctly
 874 * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
 875 */
 876int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 
 877{
 878	struct ttm_tt *ttm = &ttm_dma->ttm;
 879	struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 
 880	struct dma_pool *pool;
 
 881	enum pool_type type;
 882	unsigned i;
 883	gfp_t gfp_flags;
 884	int ret;
 885
 886	if (ttm->state != tt_unpopulated)
 887		return 0;
 888
 
 
 
 
 
 
 889	type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 
 
 890	if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 891		gfp_flags = GFP_USER | GFP_DMA32;
 892	else
 893		gfp_flags = GFP_HIGHUSER;
 894	if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 895		gfp_flags |= __GFP_ZERO;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 896
 897	pool = ttm_dma_find_pool(dev, type);
 898	if (!pool) {
 
 
 899		pool = ttm_dma_pool_init(dev, gfp_flags, type);
 900		if (IS_ERR_OR_NULL(pool)) {
 901			return -ENOMEM;
 902		}
 903	}
 904
 905	INIT_LIST_HEAD(&ttm_dma->pages_list);
 906	for (i = 0; i < ttm->num_pages; ++i) {
 907		ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
 908		if (ret != 0) {
 909			ttm_dma_unpopulate(ttm_dma, dev);
 910			return -ENOMEM;
 911		}
 912
 913		ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 914						false, false);
 915		if (unlikely(ret != 0)) {
 916			ttm_dma_unpopulate(ttm_dma, dev);
 917			return -ENOMEM;
 918		}
 
 
 
 
 919	}
 920
 921	if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 922		ret = ttm_tt_swapin(ttm);
 923		if (unlikely(ret != 0)) {
 924			ttm_dma_unpopulate(ttm_dma, dev);
 925			return ret;
 926		}
 927	}
 928
 929	ttm->state = tt_unbound;
 930	return 0;
 931}
 932EXPORT_SYMBOL_GPL(ttm_dma_populate);
 933
 934/* Put all pages in pages list to correct pool to wait for reuse */
 935void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 936{
 937	struct ttm_tt *ttm = &ttm_dma->ttm;
 
 938	struct dma_pool *pool;
 939	struct dma_page *d_page, *next;
 940	enum pool_type type;
 941	bool is_cached = false;
 942	unsigned count = 0, i, npages = 0;
 943	unsigned long irq_flags;
 944
 945	type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 946	pool = ttm_dma_find_pool(dev, type);
 947	if (!pool)
 948		return;
 949
 950	is_cached = (ttm_dma_find_pool(pool->dev,
 951		     ttm_to_type(ttm->page_flags, tt_cached)) == pool);
 952
 953	/* make sure pages array match list and count number of pages */
 954	list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) {
 
 
 955		ttm->pages[count] = d_page->p;
 956		count++;
 
 
 
 
 
 
 
 
 
 957	}
 958
 959	spin_lock_irqsave(&pool->lock, irq_flags);
 960	pool->npages_in_use -= count;
 961	if (is_cached) {
 962		pool->nfrees += count;
 963	} else {
 964		pool->npages_free += count;
 965		list_splice(&ttm_dma->pages_list, &pool->free_list);
 966		/*
 967		 * Wait to have at at least NUM_PAGES_TO_ALLOC number of pages
 968		 * to free in order to minimize calls to set_memory_wb().
 969		 */
 970		if (pool->npages_free >= (_manager->options.max_size +
 971					  NUM_PAGES_TO_ALLOC))
 972			npages = pool->npages_free - _manager->options.max_size;
 973	}
 974	spin_unlock_irqrestore(&pool->lock, irq_flags);
 975
 976	if (is_cached) {
 977		list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) {
 978			ttm_mem_global_free_page(ttm->glob->mem_glob,
 979						 d_page->p);
 980			ttm_dma_page_put(pool, d_page);
 981		}
 982	} else {
 983		for (i = 0; i < count; i++) {
 984			ttm_mem_global_free_page(ttm->glob->mem_glob,
 985						 ttm->pages[i]);
 986		}
 987	}
 988
 989	INIT_LIST_HEAD(&ttm_dma->pages_list);
 990	for (i = 0; i < ttm->num_pages; i++) {
 991		ttm->pages[i] = NULL;
 992		ttm_dma->cpu_address[i] = 0;
 993		ttm_dma->dma_address[i] = 0;
 994	}
 995
 996	/* shrink pool if necessary (only on !is_cached pools)*/
 997	if (npages)
 998		ttm_dma_page_pool_free(pool, npages, false);
 999	ttm->state = tt_unpopulated;
1000}
1001EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
1002
1003/**
1004 * Callback for mm to request pool to reduce number of page held.
1005 *
1006 * XXX: (dchinner) Deadlock warning!
1007 *
1008 * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
1009 * shrinkers
1010 */
1011static unsigned long
1012ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1013{
1014	static unsigned start_pool;
1015	unsigned idx = 0;
1016	unsigned pool_offset;
1017	unsigned shrink_pages = sc->nr_to_scan;
1018	struct device_pools *p;
1019	unsigned long freed = 0;
1020
1021	if (list_empty(&_manager->pools))
1022		return SHRINK_STOP;
1023
1024	if (!mutex_trylock(&_manager->lock))
1025		return SHRINK_STOP;
1026	if (!_manager->npools)
1027		goto out;
1028	pool_offset = ++start_pool % _manager->npools;
1029	list_for_each_entry(p, &_manager->pools, pools) {
1030		unsigned nr_free;
1031
1032		if (!p->dev)
1033			continue;
1034		if (shrink_pages == 0)
1035			break;
1036		/* Do it in round-robin fashion. */
1037		if (++idx < pool_offset)
1038			continue;
1039		nr_free = shrink_pages;
1040		/* OK to use static buffer since global mutex is held. */
1041		shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free, true);
1042		freed += nr_free - shrink_pages;
1043
1044		pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
1045			 p->pool->dev_name, p->pool->name, current->pid,
1046			 nr_free, shrink_pages);
1047	}
1048out:
1049	mutex_unlock(&_manager->lock);
1050	return freed;
1051}
1052
1053static unsigned long
1054ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
1055{
1056	struct device_pools *p;
1057	unsigned long count = 0;
1058
1059	if (!mutex_trylock(&_manager->lock))
1060		return 0;
1061	list_for_each_entry(p, &_manager->pools, pools)
1062		count += p->pool->npages_free;
1063	mutex_unlock(&_manager->lock);
1064	return count;
1065}
1066
1067static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
1068{
1069	manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count;
1070	manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
1071	manager->mm_shrink.seeks = 1;
1072	register_shrinker(&manager->mm_shrink);
1073}
1074
1075static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
1076{
1077	unregister_shrinker(&manager->mm_shrink);
1078}
1079
1080int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1081{
1082	int ret = -ENOMEM;
1083
1084	WARN_ON(_manager);
1085
1086	pr_info("Initializing DMA pool allocator\n");
1087
1088	_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1089	if (!_manager)
1090		goto err;
1091
1092	mutex_init(&_manager->lock);
1093	INIT_LIST_HEAD(&_manager->pools);
1094
1095	_manager->options.max_size = max_pages;
1096	_manager->options.small = SMALL_ALLOCATION;
1097	_manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1098
1099	/* This takes care of auto-freeing the _manager */
1100	ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1101				   &glob->kobj, "dma_pool");
1102	if (unlikely(ret != 0)) {
1103		kobject_put(&_manager->kobj);
1104		goto err;
1105	}
1106	ttm_dma_pool_mm_shrink_init(_manager);
 
1107	return 0;
1108err:
 
 
 
1109	return ret;
1110}
1111
1112void ttm_dma_page_alloc_fini(void)
1113{
1114	struct device_pools *p, *t;
1115
1116	pr_info("Finalizing DMA pool allocator\n");
1117	ttm_dma_pool_mm_shrink_fini(_manager);
1118
1119	list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
1120		dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
1121			current->pid);
1122		WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
1123			ttm_dma_pool_match, p->pool));
1124		ttm_dma_free_pool(p->dev, p->pool->type);
1125	}
1126	kobject_put(&_manager->kobj);
1127	_manager = NULL;
1128}
1129
1130int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
1131{
1132	struct device_pools *p;
1133	struct dma_pool *pool = NULL;
1134	char *h[] = {"pool", "refills", "pages freed", "inuse", "available",
1135		     "name", "virt", "busaddr"};
1136
1137	if (!_manager) {
1138		seq_printf(m, "No pool allocator running.\n");
1139		return 0;
1140	}
1141	seq_printf(m, "%13s %12s %13s %8s %8s %8s\n",
1142		   h[0], h[1], h[2], h[3], h[4], h[5]);
1143	mutex_lock(&_manager->lock);
1144	list_for_each_entry(p, &_manager->pools, pools) {
1145		struct device *dev = p->dev;
1146		if (!dev)
1147			continue;
1148		pool = p->pool;
1149		seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
1150				pool->name, pool->nrefills,
1151				pool->nfrees, pool->npages_in_use,
1152				pool->npages_free,
1153				pool->dev_name);
1154	}
1155	mutex_unlock(&_manager->lock);
1156	return 0;
1157}
1158EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);
1159
1160#endif
v5.4
   1/*
   2 * Copyright 2011 (c) Oracle Corp.
   3
   4 * Permission is hereby granted, free of charge, to any person obtaining a
   5 * copy of this software and associated documentation files (the "Software"),
   6 * to deal in the Software without restriction, including without limitation
   7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8 * and/or sell copies of the Software, and to permit persons to whom the
   9 * Software is furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice (including the
  12 * next paragraph) shall be included in all copies or substantial portions
  13 * of the Software.
  14 *
  15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21 * DEALINGS IN THE SOFTWARE.
  22 *
  23 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
  24 */
  25
  26/*
  27 * A simple DMA pool losely based on dmapool.c. It has certain advantages
  28 * over the DMA pools:
  29 * - Pool collects resently freed pages for reuse (and hooks up to
  30 *   the shrinker).
  31 * - Tracks currently in use pages
  32 * - Tracks whether the page is UC, WB or cached (and reverts to WB
  33 *   when freed).
  34 */
  35
  36#if defined(CONFIG_SWIOTLB) || defined(CONFIG_INTEL_IOMMU)
  37#define pr_fmt(fmt) "[TTM] " fmt
  38
  39#include <linux/dma-mapping.h>
  40#include <linux/list.h>
  41#include <linux/seq_file.h> /* for seq_printf */
  42#include <linux/slab.h>
  43#include <linux/spinlock.h>
  44#include <linux/highmem.h>
  45#include <linux/mm_types.h>
  46#include <linux/module.h>
  47#include <linux/mm.h>
  48#include <linux/atomic.h>
  49#include <linux/device.h>
  50#include <linux/kthread.h>
  51#include <drm/ttm/ttm_bo_driver.h>
  52#include <drm/ttm/ttm_page_alloc.h>
  53#include <drm/ttm/ttm_set_memory.h>
 
 
  54
  55#define NUM_PAGES_TO_ALLOC		(PAGE_SIZE/sizeof(struct page *))
  56#define SMALL_ALLOCATION		4
  57#define FREE_ALL_PAGES			(~0U)
  58#define VADDR_FLAG_HUGE_POOL		1UL
  59#define VADDR_FLAG_UPDATED_COUNT	2UL
 
 
 
 
  60
  61enum pool_type {
  62	IS_UNDEFINED	= 0,
  63	IS_WC		= 1 << 1,
  64	IS_UC		= 1 << 2,
  65	IS_CACHED	= 1 << 3,
  66	IS_DMA32	= 1 << 4,
  67	IS_HUGE		= 1 << 5
 
  68};
  69
  70/*
  71 * The pool structure. There are up to nine pools:
  72 *  - generic (not restricted to DMA32):
  73 *      - write combined, uncached, cached.
  74 *  - dma32 (up to 2^32 - so up 4GB):
  75 *      - write combined, uncached, cached.
  76 *  - huge (not restricted to DMA32):
  77 *      - write combined, uncached, cached.
  78 * for each 'struct device'. The 'cached' is for pages that are actively used.
  79 * The other ones can be shrunk by the shrinker API if neccessary.
  80 * @pools: The 'struct device->dma_pools' link.
  81 * @type: Type of the pool
  82 * @lock: Protects the free_list from concurrnet access. Must be
  83 * used with irqsave/irqrestore variants because pool allocator maybe called
  84 * from delayed work.
 
 
  85 * @free_list: Pool of pages that are free to be used. No order requirements.
  86 * @dev: The device that is associated with these pools.
  87 * @size: Size used during DMA allocation.
  88 * @npages_free: Count of available pages for re-use.
  89 * @npages_in_use: Count of pages that are in use.
  90 * @nfrees: Stats when pool is shrinking.
  91 * @nrefills: Stats when the pool is grown.
  92 * @gfp_flags: Flags to pass for alloc_page.
  93 * @name: Name of the pool.
  94 * @dev_name: Name derieved from dev - similar to how dev_info works.
  95 *   Used during shutdown as the dev_info during release is unavailable.
  96 */
  97struct dma_pool {
  98	struct list_head pools; /* The 'struct device->dma_pools link */
  99	enum pool_type type;
 100	spinlock_t lock;
 
 101	struct list_head free_list;
 102	struct device *dev;
 103	unsigned size;
 104	unsigned npages_free;
 105	unsigned npages_in_use;
 106	unsigned long nfrees; /* Stats when shrunk. */
 107	unsigned long nrefills; /* Stats when grown. */
 108	gfp_t gfp_flags;
 109	char name[13]; /* "cached dma32" */
 110	char dev_name[64]; /* Constructed from dev */
 111};
 112
 113/*
 114 * The accounting page keeping track of the allocated page along with
 115 * the DMA address.
 116 * @page_list: The link to the 'page_list' in 'struct dma_pool'.
 117 * @vaddr: The virtual address of the page and a flag if the page belongs to a
 118 * huge pool
 119 * @dma: The bus address of the page. If the page is not allocated
 120 *   via the DMA API, it will be -1.
 121 */
 122struct dma_page {
 123	struct list_head page_list;
 124	unsigned long vaddr;
 125	struct page *p;
 126	dma_addr_t dma;
 127};
 128
 129/*
 130 * Limits for the pool. They are handled without locks because only place where
 131 * they may change is in sysfs store. They won't have immediate effect anyway
 132 * so forcing serialization to access them is pointless.
 133 */
 134
 135struct ttm_pool_opts {
 136	unsigned	alloc_size;
 137	unsigned	max_size;
 138	unsigned	small;
 139};
 140
 141/*
 142 * Contains the list of all of the 'struct device' and their corresponding
 143 * DMA pools. Guarded by _mutex->lock.
 144 * @pools: The link to 'struct ttm_pool_manager->pools'
 145 * @dev: The 'struct device' associated with the 'pool'
 146 * @pool: The 'struct dma_pool' associated with the 'dev'
 147 */
 148struct device_pools {
 149	struct list_head pools;
 150	struct device *dev;
 151	struct dma_pool *pool;
 152};
 153
 154/*
 155 * struct ttm_pool_manager - Holds memory pools for fast allocation
 156 *
 157 * @lock: Lock used when adding/removing from pools
 158 * @pools: List of 'struct device' and 'struct dma_pool' tuples.
 159 * @options: Limits for the pool.
 160 * @npools: Total amount of pools in existence.
 161 * @shrinker: The structure used by [un|]register_shrinker
 162 */
 163struct ttm_pool_manager {
 164	struct mutex		lock;
 165	struct list_head	pools;
 166	struct ttm_pool_opts	options;
 167	unsigned		npools;
 168	struct shrinker		mm_shrink;
 169	struct kobject		kobj;
 170};
 171
 172static struct ttm_pool_manager *_manager;
 173
 174static struct attribute ttm_page_pool_max = {
 175	.name = "pool_max_size",
 176	.mode = S_IRUGO | S_IWUSR
 177};
 178static struct attribute ttm_page_pool_small = {
 179	.name = "pool_small_allocation",
 180	.mode = S_IRUGO | S_IWUSR
 181};
 182static struct attribute ttm_page_pool_alloc_size = {
 183	.name = "pool_allocation_size",
 184	.mode = S_IRUGO | S_IWUSR
 185};
 186
 187static struct attribute *ttm_pool_attrs[] = {
 188	&ttm_page_pool_max,
 189	&ttm_page_pool_small,
 190	&ttm_page_pool_alloc_size,
 191	NULL
 192};
 193
 194static void ttm_pool_kobj_release(struct kobject *kobj)
 195{
 196	struct ttm_pool_manager *m =
 197		container_of(kobj, struct ttm_pool_manager, kobj);
 198	kfree(m);
 199}
 200
 201static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
 202			      const char *buffer, size_t size)
 203{
 204	struct ttm_pool_manager *m =
 205		container_of(kobj, struct ttm_pool_manager, kobj);
 206	int chars;
 207	unsigned val;
 208
 209	chars = sscanf(buffer, "%u", &val);
 210	if (chars == 0)
 211		return size;
 212
 213	/* Convert kb to number of pages */
 214	val = val / (PAGE_SIZE >> 10);
 215
 216	if (attr == &ttm_page_pool_max) {
 217		m->options.max_size = val;
 218	} else if (attr == &ttm_page_pool_small) {
 219		m->options.small = val;
 220	} else if (attr == &ttm_page_pool_alloc_size) {
 221		if (val > NUM_PAGES_TO_ALLOC*8) {
 222			pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
 223			       NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
 224			       NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 225			return size;
 226		} else if (val > NUM_PAGES_TO_ALLOC) {
 227			pr_warn("Setting allocation size to larger than %lu is not recommended\n",
 228				NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
 229		}
 230		m->options.alloc_size = val;
 231	}
 232
 233	return size;
 234}
 235
 236static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
 237			     char *buffer)
 238{
 239	struct ttm_pool_manager *m =
 240		container_of(kobj, struct ttm_pool_manager, kobj);
 241	unsigned val = 0;
 242
 243	if (attr == &ttm_page_pool_max)
 244		val = m->options.max_size;
 245	else if (attr == &ttm_page_pool_small)
 246		val = m->options.small;
 247	else if (attr == &ttm_page_pool_alloc_size)
 248		val = m->options.alloc_size;
 249
 250	val = val * (PAGE_SIZE >> 10);
 251
 252	return snprintf(buffer, PAGE_SIZE, "%u\n", val);
 253}
 254
 255static const struct sysfs_ops ttm_pool_sysfs_ops = {
 256	.show = &ttm_pool_show,
 257	.store = &ttm_pool_store,
 258};
 259
 260static struct kobj_type ttm_pool_kobj_type = {
 261	.release = &ttm_pool_kobj_release,
 262	.sysfs_ops = &ttm_pool_sysfs_ops,
 263	.default_attrs = ttm_pool_attrs,
 264};
 265
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 266static int ttm_set_pages_caching(struct dma_pool *pool,
 267				 struct page **pages, unsigned cpages)
 268{
 269	int r = 0;
 270	/* Set page caching */
 271	if (pool->type & IS_UC) {
 272		r = ttm_set_pages_array_uc(pages, cpages);
 273		if (r)
 274			pr_err("%s: Failed to set %d pages to uc!\n",
 275			       pool->dev_name, cpages);
 276	}
 277	if (pool->type & IS_WC) {
 278		r = ttm_set_pages_array_wc(pages, cpages);
 279		if (r)
 280			pr_err("%s: Failed to set %d pages to wc!\n",
 281			       pool->dev_name, cpages);
 282	}
 283	return r;
 284}
 285
 286static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
 287{
 288	unsigned long attrs = 0;
 289	dma_addr_t dma = d_page->dma;
 290	d_page->vaddr &= ~VADDR_FLAG_HUGE_POOL;
 291	if (pool->type & IS_HUGE)
 292		attrs = DMA_ATTR_NO_WARN;
 293
 294	dma_free_attrs(pool->dev, pool->size, (void *)d_page->vaddr, dma, attrs);
 295
 296	kfree(d_page);
 297	d_page = NULL;
 298}
 299static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
 300{
 301	struct dma_page *d_page;
 302	unsigned long attrs = 0;
 303	void *vaddr;
 304
 305	d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
 306	if (!d_page)
 307		return NULL;
 308
 309	if (pool->type & IS_HUGE)
 310		attrs = DMA_ATTR_NO_WARN;
 311
 312	vaddr = dma_alloc_attrs(pool->dev, pool->size, &d_page->dma,
 313				pool->gfp_flags, attrs);
 314	if (vaddr) {
 315		if (is_vmalloc_addr(vaddr))
 316			d_page->p = vmalloc_to_page(vaddr);
 317		else
 318			d_page->p = virt_to_page(vaddr);
 319		d_page->vaddr = (unsigned long)vaddr;
 320		if (pool->type & IS_HUGE)
 321			d_page->vaddr |= VADDR_FLAG_HUGE_POOL;
 322	} else {
 323		kfree(d_page);
 324		d_page = NULL;
 325	}
 326	return d_page;
 327}
 328static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
 329{
 330	enum pool_type type = IS_UNDEFINED;
 331
 332	if (flags & TTM_PAGE_FLAG_DMA32)
 333		type |= IS_DMA32;
 334	if (cstate == tt_cached)
 335		type |= IS_CACHED;
 336	else if (cstate == tt_uncached)
 337		type |= IS_UC;
 338	else
 339		type |= IS_WC;
 340
 341	return type;
 342}
 343
 344static void ttm_pool_update_free_locked(struct dma_pool *pool,
 345					unsigned freed_pages)
 346{
 347	pool->npages_free -= freed_pages;
 348	pool->nfrees += freed_pages;
 349
 350}
 351
 352/* set memory back to wb and free the pages. */
 353static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
 354{
 355	struct page *page = d_page->p;
 356	unsigned num_pages;
 357
 358	/* Don't set WB on WB page pool. */
 359	if (!(pool->type & IS_CACHED)) {
 360		num_pages = pool->size / PAGE_SIZE;
 361		if (ttm_set_pages_wb(page, num_pages))
 362			pr_err("%s: Failed to set %d pages to wb!\n",
 363			       pool->dev_name, num_pages);
 364	}
 365
 366	list_del(&d_page->page_list);
 367	__ttm_dma_free_page(pool, d_page);
 368}
 369
 370static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
 371			      struct page *pages[], unsigned npages)
 372{
 373	struct dma_page *d_page, *tmp;
 374
 375	if (pool->type & IS_HUGE) {
 376		list_for_each_entry_safe(d_page, tmp, d_pages, page_list)
 377			ttm_dma_page_put(pool, d_page);
 378
 379		return;
 380	}
 381
 382	/* Don't set WB on WB page pool. */
 383	if (npages && !(pool->type & IS_CACHED) &&
 384	    ttm_set_pages_array_wb(pages, npages))
 385		pr_err("%s: Failed to set %d pages to wb!\n",
 386		       pool->dev_name, npages);
 387
 388	list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 389		list_del(&d_page->page_list);
 390		__ttm_dma_free_page(pool, d_page);
 391	}
 392}
 393
 
 
 
 
 
 
 
 
 
 
 
 394/*
 395 * Free pages from pool.
 396 *
 397 * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
 398 * number of pages in one go.
 399 *
 400 * @pool: to free the pages from
 401 * @nr_free: If set to true will free all pages in pool
 402 * @use_static: Safe to use static buffer
 403 **/
 404static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
 405				       bool use_static)
 406{
 407	static struct page *static_buf[NUM_PAGES_TO_ALLOC];
 408	unsigned long irq_flags;
 409	struct dma_page *dma_p, *tmp;
 410	struct page **pages_to_free;
 411	struct list_head d_pages;
 412	unsigned freed_pages = 0,
 413		 npages_to_free = nr_free;
 414
 415	if (NUM_PAGES_TO_ALLOC < nr_free)
 416		npages_to_free = NUM_PAGES_TO_ALLOC;
 417
 
 
 
 
 
 
 418	if (use_static)
 419		pages_to_free = static_buf;
 420	else
 421		pages_to_free = kmalloc_array(npages_to_free,
 422					      sizeof(struct page *),
 423					      GFP_KERNEL);
 424
 425	if (!pages_to_free) {
 426		pr_debug("%s: Failed to allocate memory for pool free operation\n",
 427		       pool->dev_name);
 428		return 0;
 429	}
 430	INIT_LIST_HEAD(&d_pages);
 431restart:
 432	spin_lock_irqsave(&pool->lock, irq_flags);
 433
 434	/* We picking the oldest ones off the list */
 435	list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
 436					 page_list) {
 437		if (freed_pages >= npages_to_free)
 438			break;
 439
 440		/* Move the dma_page from one list to another. */
 441		list_move(&dma_p->page_list, &d_pages);
 442
 443		pages_to_free[freed_pages++] = dma_p->p;
 444		/* We can only remove NUM_PAGES_TO_ALLOC at a time. */
 445		if (freed_pages >= NUM_PAGES_TO_ALLOC) {
 446
 447			ttm_pool_update_free_locked(pool, freed_pages);
 448			/**
 449			 * Because changing page caching is costly
 450			 * we unlock the pool to prevent stalling.
 451			 */
 452			spin_unlock_irqrestore(&pool->lock, irq_flags);
 453
 454			ttm_dma_pages_put(pool, &d_pages, pages_to_free,
 455					  freed_pages);
 456
 457			INIT_LIST_HEAD(&d_pages);
 458
 459			if (likely(nr_free != FREE_ALL_PAGES))
 460				nr_free -= freed_pages;
 461
 462			if (NUM_PAGES_TO_ALLOC >= nr_free)
 463				npages_to_free = nr_free;
 464			else
 465				npages_to_free = NUM_PAGES_TO_ALLOC;
 466
 467			freed_pages = 0;
 468
 469			/* free all so restart the processing */
 470			if (nr_free)
 471				goto restart;
 472
 473			/* Not allowed to fall through or break because
 474			 * following context is inside spinlock while we are
 475			 * outside here.
 476			 */
 477			goto out;
 478
 479		}
 480	}
 481
 482	/* remove range of pages from the pool */
 483	if (freed_pages) {
 484		ttm_pool_update_free_locked(pool, freed_pages);
 485		nr_free -= freed_pages;
 486	}
 487
 488	spin_unlock_irqrestore(&pool->lock, irq_flags);
 489
 490	if (freed_pages)
 491		ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
 492out:
 493	if (pages_to_free != static_buf)
 494		kfree(pages_to_free);
 495	return nr_free;
 496}
 497
 498static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
 499{
 500	struct device_pools *p;
 501	struct dma_pool *pool;
 502
 503	if (!dev)
 504		return;
 505
 506	mutex_lock(&_manager->lock);
 507	list_for_each_entry_reverse(p, &_manager->pools, pools) {
 508		if (p->dev != dev)
 509			continue;
 510		pool = p->pool;
 511		if (pool->type != type)
 512			continue;
 513
 514		list_del(&p->pools);
 515		kfree(p);
 516		_manager->npools--;
 517		break;
 518	}
 519	list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
 520		if (pool->type != type)
 521			continue;
 522		/* Takes a spinlock.. */
 523		/* OK to use static buffer since global mutex is held. */
 524		ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, true);
 525		WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
 526		/* This code path is called after _all_ references to the
 527		 * struct device has been dropped - so nobody should be
 528		 * touching it. In case somebody is trying to _add_ we are
 529		 * guarded by the mutex. */
 530		list_del(&pool->pools);
 531		kfree(pool);
 532		break;
 533	}
 534	mutex_unlock(&_manager->lock);
 535}
 536
 537/*
 538 * On free-ing of the 'struct device' this deconstructor is run.
 539 * Albeit the pool might have already been freed earlier.
 540 */
 541static void ttm_dma_pool_release(struct device *dev, void *res)
 542{
 543	struct dma_pool *pool = *(struct dma_pool **)res;
 544
 545	if (pool)
 546		ttm_dma_free_pool(dev, pool->type);
 547}
 548
 549static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
 550{
 551	return *(struct dma_pool **)res == match_data;
 552}
 553
 554static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
 555					  enum pool_type type)
 556{
 557	const char *n[] = {"wc", "uc", "cached", " dma32", "huge"};
 558	enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_HUGE};
 559	struct device_pools *sec_pool = NULL;
 560	struct dma_pool *pool = NULL, **ptr;
 561	unsigned i;
 562	int ret = -ENODEV;
 563	char *p;
 564
 565	if (!dev)
 566		return NULL;
 567
 568	ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
 569	if (!ptr)
 570		return NULL;
 571
 572	ret = -ENOMEM;
 573
 574	pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
 575			    dev_to_node(dev));
 576	if (!pool)
 577		goto err_mem;
 578
 579	sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
 580				dev_to_node(dev));
 581	if (!sec_pool)
 582		goto err_mem;
 583
 584	INIT_LIST_HEAD(&sec_pool->pools);
 585	sec_pool->dev = dev;
 586	sec_pool->pool =  pool;
 587
 588	INIT_LIST_HEAD(&pool->free_list);
 
 589	INIT_LIST_HEAD(&pool->pools);
 590	spin_lock_init(&pool->lock);
 591	pool->dev = dev;
 592	pool->npages_free = pool->npages_in_use = 0;
 593	pool->nfrees = 0;
 594	pool->gfp_flags = flags;
 595	if (type & IS_HUGE)
 596#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 597		pool->size = HPAGE_PMD_SIZE;
 598#else
 599		BUG();
 600#endif
 601	else
 602		pool->size = PAGE_SIZE;
 603	pool->type = type;
 604	pool->nrefills = 0;
 605	p = pool->name;
 606	for (i = 0; i < ARRAY_SIZE(t); i++) {
 607		if (type & t[i]) {
 608			p += snprintf(p, sizeof(pool->name) - (p - pool->name),
 609				      "%s", n[i]);
 610		}
 611	}
 612	*p = 0;
 613	/* We copy the name for pr_ calls b/c when dma_pool_destroy is called
 614	 * - the kobj->name has already been deallocated.*/
 615	snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
 616		 dev_driver_string(dev), dev_name(dev));
 617	mutex_lock(&_manager->lock);
 618	/* You can get the dma_pool from either the global: */
 619	list_add(&sec_pool->pools, &_manager->pools);
 620	_manager->npools++;
 621	/* or from 'struct device': */
 622	list_add(&pool->pools, &dev->dma_pools);
 623	mutex_unlock(&_manager->lock);
 624
 625	*ptr = pool;
 626	devres_add(dev, ptr);
 627
 628	return pool;
 629err_mem:
 630	devres_free(ptr);
 631	kfree(sec_pool);
 632	kfree(pool);
 633	return ERR_PTR(ret);
 634}
 635
 636static struct dma_pool *ttm_dma_find_pool(struct device *dev,
 637					  enum pool_type type)
 638{
 639	struct dma_pool *pool, *tmp;
 640
 641	if (type == IS_UNDEFINED)
 642		return NULL;
 643
 644	/* NB: We iterate on the 'struct dev' which has no spinlock, but
 645	 * it does have a kref which we have taken. The kref is taken during
 646	 * graphic driver loading - in the drm_pci_init it calls either
 647	 * pci_dev_get or pci_register_driver which both end up taking a kref
 648	 * on 'struct device'.
 649	 *
 650	 * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
 651	 * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
 652	 * thing is at that point of time there are no pages associated with the
 653	 * driver so this function will not be called.
 654	 */
 655	list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools)
 656		if (pool->type == type)
 657			return pool;
 658	return NULL;
 
 
 
 659}
 660
 661/*
 662 * Free pages the pages that failed to change the caching state. If there
 663 * are pages that have changed their caching state already put them to the
 664 * pool.
 665 */
 666static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
 667						 struct list_head *d_pages,
 668						 struct page **failed_pages,
 669						 unsigned cpages)
 670{
 671	struct dma_page *d_page, *tmp;
 672	struct page *p;
 673	unsigned i = 0;
 674
 675	p = failed_pages[0];
 676	if (!p)
 677		return;
 678	/* Find the failed page. */
 679	list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
 680		if (d_page->p != p)
 681			continue;
 682		/* .. and then progress over the full list. */
 683		list_del(&d_page->page_list);
 684		__ttm_dma_free_page(pool, d_page);
 685		if (++i < cpages)
 686			p = failed_pages[i];
 687		else
 688			break;
 689	}
 690
 691}
 692
 693/*
 694 * Allocate 'count' pages, and put 'need' number of them on the
 695 * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
 696 * The full list of pages should also be on 'd_pages'.
 697 * We return zero for success, and negative numbers as errors.
 698 */
 699static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
 700					struct list_head *d_pages,
 701					unsigned count)
 702{
 703	struct page **caching_array;
 704	struct dma_page *dma_p;
 705	struct page *p;
 706	int r = 0;
 707	unsigned i, j, npages, cpages;
 708	unsigned max_cpages = min(count,
 709			(unsigned)(PAGE_SIZE/sizeof(struct page *)));
 710
 711	/* allocate array for page caching change */
 712	caching_array = kmalloc_array(max_cpages, sizeof(struct page *),
 713				      GFP_KERNEL);
 714
 715	if (!caching_array) {
 716		pr_debug("%s: Unable to allocate table for new pages\n",
 717		       pool->dev_name);
 718		return -ENOMEM;
 719	}
 720
 721	if (count > 1)
 722		pr_debug("%s: (%s:%d) Getting %d pages\n",
 723			 pool->dev_name, pool->name, current->pid, count);
 
 724
 725	for (i = 0, cpages = 0; i < count; ++i) {
 726		dma_p = __ttm_dma_alloc_page(pool);
 727		if (!dma_p) {
 728			pr_debug("%s: Unable to get page %u\n",
 729				 pool->dev_name, i);
 730
 731			/* store already allocated pages in the pool after
 732			 * setting the caching state */
 733			if (cpages) {
 734				r = ttm_set_pages_caching(pool, caching_array,
 735							  cpages);
 736				if (r)
 737					ttm_dma_handle_caching_state_failure(
 738						pool, d_pages, caching_array,
 739						cpages);
 740			}
 741			r = -ENOMEM;
 742			goto out;
 743		}
 744		p = dma_p->p;
 745		list_add(&dma_p->page_list, d_pages);
 746
 747#ifdef CONFIG_HIGHMEM
 748		/* gfp flags of highmem page should never be dma32 so we
 749		 * we should be fine in such case
 750		 */
 751		if (PageHighMem(p))
 752			continue;
 753#endif
 754
 755		npages = pool->size / PAGE_SIZE;
 756		for (j = 0; j < npages; ++j) {
 757			caching_array[cpages++] = p + j;
 758			if (cpages == max_cpages) {
 759				/* Note: Cannot hold the spinlock */
 760				r = ttm_set_pages_caching(pool, caching_array,
 761							  cpages);
 762				if (r) {
 763					ttm_dma_handle_caching_state_failure(
 764					     pool, d_pages, caching_array,
 765					     cpages);
 766					goto out;
 767				}
 768				cpages = 0;
 769			}
 770		}
 
 771	}
 772
 773	if (cpages) {
 774		r = ttm_set_pages_caching(pool, caching_array, cpages);
 775		if (r)
 776			ttm_dma_handle_caching_state_failure(pool, d_pages,
 777					caching_array, cpages);
 778	}
 779out:
 780	kfree(caching_array);
 781	return r;
 782}
 783
 784/*
 785 * @return count of pages still required to fulfill the request.
 786 */
 787static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
 788					 unsigned long *irq_flags)
 789{
 790	unsigned count = _manager->options.small;
 791	int r = pool->npages_free;
 792
 793	if (count > pool->npages_free) {
 794		struct list_head d_pages;
 795
 796		INIT_LIST_HEAD(&d_pages);
 797
 798		spin_unlock_irqrestore(&pool->lock, *irq_flags);
 799
 800		/* Returns how many more are neccessary to fulfill the
 801		 * request. */
 802		r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
 803
 804		spin_lock_irqsave(&pool->lock, *irq_flags);
 805		if (!r) {
 806			/* Add the fresh to the end.. */
 807			list_splice(&d_pages, &pool->free_list);
 808			++pool->nrefills;
 809			pool->npages_free += count;
 810			r = count;
 811		} else {
 812			struct dma_page *d_page;
 813			unsigned cpages = 0;
 814
 815			pr_debug("%s: Failed to fill %s pool (r:%d)!\n",
 816				 pool->dev_name, pool->name, r);
 817
 818			list_for_each_entry(d_page, &d_pages, page_list) {
 819				cpages++;
 820			}
 821			list_splice_tail(&d_pages, &pool->free_list);
 822			pool->npages_free += cpages;
 823			r = cpages;
 824		}
 825	}
 826	return r;
 827}
 828
 829/*
 
 830 * The populate list is actually a stack (not that is matters as TTM
 831 * allocates one page at a time.
 832 * return dma_page pointer if success, otherwise NULL.
 833 */
 834static struct dma_page *ttm_dma_pool_get_pages(struct dma_pool *pool,
 835				  struct ttm_dma_tt *ttm_dma,
 836				  unsigned index)
 837{
 838	struct dma_page *d_page = NULL;
 839	struct ttm_tt *ttm = &ttm_dma->ttm;
 840	unsigned long irq_flags;
 841	int count;
 842
 843	spin_lock_irqsave(&pool->lock, irq_flags);
 844	count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
 845	if (count) {
 846		d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
 847		ttm->pages[index] = d_page->p;
 
 848		ttm_dma->dma_address[index] = d_page->dma;
 849		list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
 
 850		pool->npages_in_use += 1;
 851		pool->npages_free -= 1;
 852	}
 853	spin_unlock_irqrestore(&pool->lock, irq_flags);
 854	return d_page;
 855}
 856
 857static gfp_t ttm_dma_pool_gfp_flags(struct ttm_dma_tt *ttm_dma, bool huge)
 858{
 859	struct ttm_tt *ttm = &ttm_dma->ttm;
 860	gfp_t gfp_flags;
 861
 862	if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 863		gfp_flags = GFP_USER | GFP_DMA32;
 864	else
 865		gfp_flags = GFP_HIGHUSER;
 866	if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 867		gfp_flags |= __GFP_ZERO;
 868
 869	if (huge) {
 870		gfp_flags |= GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
 871			__GFP_KSWAPD_RECLAIM;
 872		gfp_flags &= ~__GFP_MOVABLE;
 873		gfp_flags &= ~__GFP_COMP;
 874	}
 875
 876	if (ttm->page_flags & TTM_PAGE_FLAG_NO_RETRY)
 877		gfp_flags |= __GFP_RETRY_MAYFAIL;
 878
 879	return gfp_flags;
 880}
 881
 882/*
 883 * On success pages list will hold count number of correctly
 884 * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
 885 */
 886int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
 887			struct ttm_operation_ctx *ctx)
 888{
 889	struct ttm_tt *ttm = &ttm_dma->ttm;
 890	struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
 891	unsigned long num_pages = ttm->num_pages;
 892	struct dma_pool *pool;
 893	struct dma_page *d_page;
 894	enum pool_type type;
 895	unsigned i;
 
 896	int ret;
 897
 898	if (ttm->state != tt_unpopulated)
 899		return 0;
 900
 901	if (ttm_check_under_lowerlimit(mem_glob, num_pages, ctx))
 902		return -ENOMEM;
 903
 904	INIT_LIST_HEAD(&ttm_dma->pages_list);
 905	i = 0;
 906
 907	type = ttm_to_type(ttm->page_flags, ttm->caching_state);
 908
 909#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 910	if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
 911		goto skip_huge;
 912
 913	pool = ttm_dma_find_pool(dev, type | IS_HUGE);
 914	if (!pool) {
 915		gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, true);
 916
 917		pool = ttm_dma_pool_init(dev, gfp_flags, type | IS_HUGE);
 918		if (IS_ERR_OR_NULL(pool))
 919			goto skip_huge;
 920	}
 921
 922	while (num_pages >= HPAGE_PMD_NR) {
 923		unsigned j;
 924
 925		d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
 926		if (!d_page)
 927			break;
 928
 929		ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 930						pool->size, ctx);
 931		if (unlikely(ret != 0)) {
 932			ttm_dma_unpopulate(ttm_dma, dev);
 933			return -ENOMEM;
 934		}
 935
 936		d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
 937		for (j = i + 1; j < (i + HPAGE_PMD_NR); ++j) {
 938			ttm->pages[j] = ttm->pages[j - 1] + 1;
 939			ttm_dma->dma_address[j] = ttm_dma->dma_address[j - 1] +
 940				PAGE_SIZE;
 941		}
 942
 943		i += HPAGE_PMD_NR;
 944		num_pages -= HPAGE_PMD_NR;
 945	}
 946
 947skip_huge:
 948#endif
 949
 950	pool = ttm_dma_find_pool(dev, type);
 951	if (!pool) {
 952		gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, false);
 953
 954		pool = ttm_dma_pool_init(dev, gfp_flags, type);
 955		if (IS_ERR_OR_NULL(pool))
 956			return -ENOMEM;
 
 957	}
 958
 959	while (num_pages) {
 960		d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
 961		if (!d_page) {
 
 962			ttm_dma_unpopulate(ttm_dma, dev);
 963			return -ENOMEM;
 964		}
 965
 966		ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
 967						pool->size, ctx);
 968		if (unlikely(ret != 0)) {
 969			ttm_dma_unpopulate(ttm_dma, dev);
 970			return -ENOMEM;
 971		}
 972
 973		d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
 974		++i;
 975		--num_pages;
 976	}
 977
 978	if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 979		ret = ttm_tt_swapin(ttm);
 980		if (unlikely(ret != 0)) {
 981			ttm_dma_unpopulate(ttm_dma, dev);
 982			return ret;
 983		}
 984	}
 985
 986	ttm->state = tt_unbound;
 987	return 0;
 988}
 989EXPORT_SYMBOL_GPL(ttm_dma_populate);
 990
 991/* Put all pages in pages list to correct pool to wait for reuse */
 992void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 993{
 994	struct ttm_tt *ttm = &ttm_dma->ttm;
 995	struct ttm_mem_global *mem_glob = ttm->bdev->glob->mem_glob;
 996	struct dma_pool *pool;
 997	struct dma_page *d_page, *next;
 998	enum pool_type type;
 999	bool is_cached = false;
1000	unsigned count, i, npages = 0;
1001	unsigned long irq_flags;
1002
1003	type = ttm_to_type(ttm->page_flags, ttm->caching_state);
1004
1005#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1006	pool = ttm_dma_find_pool(dev, type | IS_HUGE);
1007	if (pool) {
1008		count = 0;
1009		list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
1010					 page_list) {
1011			if (!(d_page->vaddr & VADDR_FLAG_HUGE_POOL))
1012				continue;
1013
1014			count++;
1015			if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
1016				ttm_mem_global_free_page(mem_glob, d_page->p,
1017							 pool->size);
1018				d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
1019			}
1020			ttm_dma_page_put(pool, d_page);
1021		}
1022
1023		spin_lock_irqsave(&pool->lock, irq_flags);
1024		pool->npages_in_use -= count;
1025		pool->nfrees += count;
1026		spin_unlock_irqrestore(&pool->lock, irq_flags);
1027	}
1028#endif
1029
1030	pool = ttm_dma_find_pool(dev, type);
1031	if (!pool)
1032		return;
1033
1034	is_cached = (ttm_dma_find_pool(pool->dev,
1035		     ttm_to_type(ttm->page_flags, tt_cached)) == pool);
1036
1037	/* make sure pages array match list and count number of pages */
1038	count = 0;
1039	list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
1040				 page_list) {
1041		ttm->pages[count] = d_page->p;
1042		count++;
1043
1044		if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
1045			ttm_mem_global_free_page(mem_glob, d_page->p,
1046						 pool->size);
1047			d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
1048		}
1049
1050		if (is_cached)
1051			ttm_dma_page_put(pool, d_page);
1052	}
1053
1054	spin_lock_irqsave(&pool->lock, irq_flags);
1055	pool->npages_in_use -= count;
1056	if (is_cached) {
1057		pool->nfrees += count;
1058	} else {
1059		pool->npages_free += count;
1060		list_splice(&ttm_dma->pages_list, &pool->free_list);
1061		/*
1062		 * Wait to have at at least NUM_PAGES_TO_ALLOC number of pages
1063		 * to free in order to minimize calls to set_memory_wb().
1064		 */
1065		if (pool->npages_free >= (_manager->options.max_size +
1066					  NUM_PAGES_TO_ALLOC))
1067			npages = pool->npages_free - _manager->options.max_size;
1068	}
1069	spin_unlock_irqrestore(&pool->lock, irq_flags);
1070
 
 
 
 
 
 
 
 
 
 
 
 
 
1071	INIT_LIST_HEAD(&ttm_dma->pages_list);
1072	for (i = 0; i < ttm->num_pages; i++) {
1073		ttm->pages[i] = NULL;
 
1074		ttm_dma->dma_address[i] = 0;
1075	}
1076
1077	/* shrink pool if necessary (only on !is_cached pools)*/
1078	if (npages)
1079		ttm_dma_page_pool_free(pool, npages, false);
1080	ttm->state = tt_unpopulated;
1081}
1082EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
1083
1084/**
1085 * Callback for mm to request pool to reduce number of page held.
1086 *
1087 * XXX: (dchinner) Deadlock warning!
1088 *
1089 * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
1090 * shrinkers
1091 */
1092static unsigned long
1093ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1094{
1095	static unsigned start_pool;
1096	unsigned idx = 0;
1097	unsigned pool_offset;
1098	unsigned shrink_pages = sc->nr_to_scan;
1099	struct device_pools *p;
1100	unsigned long freed = 0;
1101
1102	if (list_empty(&_manager->pools))
1103		return SHRINK_STOP;
1104
1105	if (!mutex_trylock(&_manager->lock))
1106		return SHRINK_STOP;
1107	if (!_manager->npools)
1108		goto out;
1109	pool_offset = ++start_pool % _manager->npools;
1110	list_for_each_entry(p, &_manager->pools, pools) {
1111		unsigned nr_free;
1112
1113		if (!p->dev)
1114			continue;
1115		if (shrink_pages == 0)
1116			break;
1117		/* Do it in round-robin fashion. */
1118		if (++idx < pool_offset)
1119			continue;
1120		nr_free = shrink_pages;
1121		/* OK to use static buffer since global mutex is held. */
1122		shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free, true);
1123		freed += nr_free - shrink_pages;
1124
1125		pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
1126			 p->pool->dev_name, p->pool->name, current->pid,
1127			 nr_free, shrink_pages);
1128	}
1129out:
1130	mutex_unlock(&_manager->lock);
1131	return freed;
1132}
1133
1134static unsigned long
1135ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
1136{
1137	struct device_pools *p;
1138	unsigned long count = 0;
1139
1140	if (!mutex_trylock(&_manager->lock))
1141		return 0;
1142	list_for_each_entry(p, &_manager->pools, pools)
1143		count += p->pool->npages_free;
1144	mutex_unlock(&_manager->lock);
1145	return count;
1146}
1147
1148static int ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
1149{
1150	manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count;
1151	manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
1152	manager->mm_shrink.seeks = 1;
1153	return register_shrinker(&manager->mm_shrink);
1154}
1155
1156static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
1157{
1158	unregister_shrinker(&manager->mm_shrink);
1159}
1160
1161int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
1162{
1163	int ret;
1164
1165	WARN_ON(_manager);
1166
1167	pr_info("Initializing DMA pool allocator\n");
1168
1169	_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
1170	if (!_manager)
1171		return -ENOMEM;
1172
1173	mutex_init(&_manager->lock);
1174	INIT_LIST_HEAD(&_manager->pools);
1175
1176	_manager->options.max_size = max_pages;
1177	_manager->options.small = SMALL_ALLOCATION;
1178	_manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
1179
1180	/* This takes care of auto-freeing the _manager */
1181	ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
1182				   &glob->kobj, "dma_pool");
1183	if (unlikely(ret != 0))
1184		goto error;
1185
1186	ret = ttm_dma_pool_mm_shrink_init(_manager);
1187	if (unlikely(ret != 0))
1188		goto error;
1189	return 0;
1190
1191error:
1192	kobject_put(&_manager->kobj);
1193	_manager = NULL;
1194	return ret;
1195}
1196
1197void ttm_dma_page_alloc_fini(void)
1198{
1199	struct device_pools *p, *t;
1200
1201	pr_info("Finalizing DMA pool allocator\n");
1202	ttm_dma_pool_mm_shrink_fini(_manager);
1203
1204	list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
1205		dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
1206			current->pid);
1207		WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
1208			ttm_dma_pool_match, p->pool));
1209		ttm_dma_free_pool(p->dev, p->pool->type);
1210	}
1211	kobject_put(&_manager->kobj);
1212	_manager = NULL;
1213}
1214
1215int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
1216{
1217	struct device_pools *p;
1218	struct dma_pool *pool = NULL;
 
 
1219
1220	if (!_manager) {
1221		seq_printf(m, "No pool allocator running.\n");
1222		return 0;
1223	}
1224	seq_printf(m, "         pool      refills   pages freed    inuse available     name\n");
 
1225	mutex_lock(&_manager->lock);
1226	list_for_each_entry(p, &_manager->pools, pools) {
1227		struct device *dev = p->dev;
1228		if (!dev)
1229			continue;
1230		pool = p->pool;
1231		seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
1232				pool->name, pool->nrefills,
1233				pool->nfrees, pool->npages_in_use,
1234				pool->npages_free,
1235				pool->dev_name);
1236	}
1237	mutex_unlock(&_manager->lock);
1238	return 0;
1239}
1240EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);
1241
1242#endif