--- /dev/null
+/*
+ * Copyright 2011 (c) Oracle Corp.
+
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+ */
+
+/*
+ * A simple DMA pool losely based on dmapool.c. It has certain advantages
+ * over the DMA pools:
+ * - Pool collects resently freed pages for reuse (and hooks up to
+ * the shrinker).
+ * - Tracks currently in use pages
+ * - Tracks whether the page is UC, WB or cached (and reverts to WB
+ * when freed).
+ */
+
+#if defined(CONFIG_SWIOTLB) || defined(CONFIG_INTEL_IOMMU)
+#define pr_fmt(fmt) "[TTM] " fmt
+
+#include <linux/dma-mapping.h>
+#include <linux/list.h>
+#include <linux/seq_file.h> /* for seq_printf */
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/highmem.h>
+#include <linux/mm_types.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/atomic.h>
+#include <linux/device.h>
+#include <linux/kthread.h>
+#include <drm/ttm/ttm_bo_driver.h>
+#include <drm/ttm/ttm_page_alloc.h>
+#ifdef TTM_HAS_AGP
+#include <asm/agp.h>
+#endif
+
+#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *))
+#define SMALL_ALLOCATION 4
+#define FREE_ALL_PAGES (~0U)
+/* times are in msecs */
+#define IS_UNDEFINED (0)
+#define IS_WC (1<<1)
+#define IS_UC (1<<2)
+#define IS_CACHED (1<<3)
+#define IS_DMA32 (1<<4)
+
+enum pool_type {
+ POOL_IS_UNDEFINED,
+ POOL_IS_WC = IS_WC,
+ POOL_IS_UC = IS_UC,
+ POOL_IS_CACHED = IS_CACHED,
+ POOL_IS_WC_DMA32 = IS_WC | IS_DMA32,
+ POOL_IS_UC_DMA32 = IS_UC | IS_DMA32,
+ POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32,
+};
+/*
+ * The pool structure. There are usually six pools:
+ * - generic (not restricted to DMA32):
+ * - write combined, uncached, cached.
+ * - dma32 (up to 2^32 - so up 4GB):
+ * - write combined, uncached, cached.
+ * for each 'struct device'. The 'cached' is for pages that are actively used.
+ * The other ones can be shrunk by the shrinker API if neccessary.
+ * @pools: The 'struct device->dma_pools' link.
+ * @type: Type of the pool
+ * @lock: Protects the inuse_list and free_list from concurrnet access. Must be
+ * used with irqsave/irqrestore variants because pool allocator maybe called
+ * from delayed work.
+ * @inuse_list: Pool of pages that are in use. The order is very important and
+ * it is in the order that the TTM pages that are put back are in.
+ * @free_list: Pool of pages that are free to be used. No order requirements.
+ * @dev: The device that is associated with these pools.
+ * @size: Size used during DMA allocation.
+ * @npages_free: Count of available pages for re-use.
+ * @npages_in_use: Count of pages that are in use.
+ * @nfrees: Stats when pool is shrinking.
+ * @nrefills: Stats when the pool is grown.
+ * @gfp_flags: Flags to pass for alloc_page.
+ * @name: Name of the pool.
+ * @dev_name: Name derieved from dev - similar to how dev_info works.
+ * Used during shutdown as the dev_info during release is unavailable.
+ */
+struct dma_pool {
+ struct list_head pools; /* The 'struct device->dma_pools link */
+ enum pool_type type;
+ spinlock_t lock;
+ struct list_head inuse_list;
+ struct list_head free_list;
+ struct device *dev;
+ unsigned size;
+ unsigned npages_free;
+ unsigned npages_in_use;
+ unsigned long nfrees; /* Stats when shrunk. */
+ unsigned long nrefills; /* Stats when grown. */
+ gfp_t gfp_flags;
+ char name[13]; /* "cached dma32" */
+ char dev_name[64]; /* Constructed from dev */
+};
+
+/*
+ * The accounting page keeping track of the allocated page along with
+ * the DMA address.
+ * @page_list: The link to the 'page_list' in 'struct dma_pool'.
+ * @vaddr: The virtual address of the page
+ * @dma: The bus address of the page. If the page is not allocated
+ * via the DMA API, it will be -1.
+ */
+struct dma_page {
+ struct list_head page_list;
+ void *vaddr;
+ struct page *p;
+ dma_addr_t dma;
+};
+
+/*
+ * Limits for the pool. They are handled without locks because only place where
+ * they may change is in sysfs store. They won't have immediate effect anyway
+ * so forcing serialization to access them is pointless.
+ */
+
+struct ttm_pool_opts {
+ unsigned alloc_size;
+ unsigned max_size;
+ unsigned small;
+};
+
+/*
+ * Contains the list of all of the 'struct device' and their corresponding
+ * DMA pools. Guarded by _mutex->lock.
+ * @pools: The link to 'struct ttm_pool_manager->pools'
+ * @dev: The 'struct device' associated with the 'pool'
+ * @pool: The 'struct dma_pool' associated with the 'dev'
+ */
+struct device_pools {
+ struct list_head pools;
+ struct device *dev;
+ struct dma_pool *pool;
+};
+
+/*
+ * struct ttm_pool_manager - Holds memory pools for fast allocation
+ *
+ * @lock: Lock used when adding/removing from pools
+ * @pools: List of 'struct device' and 'struct dma_pool' tuples.
+ * @options: Limits for the pool.
+ * @npools: Total amount of pools in existence.
+ * @shrinker: The structure used by [un|]register_shrinker
+ */
+struct ttm_pool_manager {
+ struct mutex lock;
+ struct list_head pools;
+ struct ttm_pool_opts options;
+ unsigned npools;
+ struct shrinker mm_shrink;
+ struct kobject kobj;
+};
+
+static struct ttm_pool_manager *_manager;
+
+static struct attribute ttm_page_pool_max = {
+ .name = "pool_max_size",
+ .mode = S_IRUGO | S_IWUSR
+};
+static struct attribute ttm_page_pool_small = {
+ .name = "pool_small_allocation",
+ .mode = S_IRUGO | S_IWUSR
+};
+static struct attribute ttm_page_pool_alloc_size = {
+ .name = "pool_allocation_size",
+ .mode = S_IRUGO | S_IWUSR
+};
+
+static struct attribute *ttm_pool_attrs[] = {
+ &ttm_page_pool_max,
+ &ttm_page_pool_small,
+ &ttm_page_pool_alloc_size,
+ NULL
+};
+
+static void ttm_pool_kobj_release(struct kobject *kobj)
+{
+ struct ttm_pool_manager *m =
+ container_of(kobj, struct ttm_pool_manager, kobj);
+ kfree(m);
+}
+
+static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
+ const char *buffer, size_t size)
+{
+ struct ttm_pool_manager *m =
+ container_of(kobj, struct ttm_pool_manager, kobj);
+ int chars;
+ unsigned val;
+ chars = sscanf(buffer, "%u", &val);
+ if (chars == 0)
+ return size;
+
+ /* Convert kb to number of pages */
+ val = val / (PAGE_SIZE >> 10);
+
+ if (attr == &ttm_page_pool_max)
+ m->options.max_size = val;
+ else if (attr == &ttm_page_pool_small)
+ m->options.small = val;
+ else if (attr == &ttm_page_pool_alloc_size) {
+ if (val > NUM_PAGES_TO_ALLOC*8) {
+ pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
+ NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
+ NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
+ return size;
+ } else if (val > NUM_PAGES_TO_ALLOC) {
+ pr_warn("Setting allocation size to larger than %lu is not recommended\n",
+ NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
+ }
+ m->options.alloc_size = val;
+ }
+
+ return size;
+}
+
+static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
+ char *buffer)
+{
+ struct ttm_pool_manager *m =
+ container_of(kobj, struct ttm_pool_manager, kobj);
+ unsigned val = 0;
+
+ if (attr == &ttm_page_pool_max)
+ val = m->options.max_size;
+ else if (attr == &ttm_page_pool_small)
+ val = m->options.small;
+ else if (attr == &ttm_page_pool_alloc_size)
+ val = m->options.alloc_size;
+
+ val = val * (PAGE_SIZE >> 10);
+
+ return snprintf(buffer, PAGE_SIZE, "%u\n", val);
+}
+
+static const struct sysfs_ops ttm_pool_sysfs_ops = {
+ .show = &ttm_pool_show,
+ .store = &ttm_pool_store,
+};
+
+static struct kobj_type ttm_pool_kobj_type = {
+ .release = &ttm_pool_kobj_release,
+ .sysfs_ops = &ttm_pool_sysfs_ops,
+ .default_attrs = ttm_pool_attrs,
+};
+
+#ifndef CONFIG_X86
+static int set_pages_array_wb(struct page **pages, int addrinarray)
+{
+#ifdef TTM_HAS_AGP
+ int i;
+
+ for (i = 0; i < addrinarray; i++)
+ unmap_page_from_agp(pages[i]);
+#endif
+ return 0;
+}
+
+static int set_pages_array_wc(struct page **pages, int addrinarray)
+{
+#ifdef TTM_HAS_AGP
+ int i;
+
+ for (i = 0; i < addrinarray; i++)
+ map_page_into_agp(pages[i]);
+#endif
+ return 0;
+}
+
+static int set_pages_array_uc(struct page **pages, int addrinarray)
+{
+#ifdef TTM_HAS_AGP
+ int i;
+
+ for (i = 0; i < addrinarray; i++)
+ map_page_into_agp(pages[i]);
+#endif
+ return 0;
+}
+#endif /* for !CONFIG_X86 */
+
+static int ttm_set_pages_caching(struct dma_pool *pool,
+ struct page **pages, unsigned cpages)
+{
+ int r = 0;
+ /* Set page caching */
+ if (pool->type & IS_UC) {
+ r = set_pages_array_uc(pages, cpages);
+ if (r)
+ pr_err("%s: Failed to set %d pages to uc!\n",
+ pool->dev_name, cpages);
+ }
+ if (pool->type & IS_WC) {
+ r = set_pages_array_wc(pages, cpages);
+ if (r)
+ pr_err("%s: Failed to set %d pages to wc!\n",
+ pool->dev_name, cpages);
+ }
+ return r;
+}
+
+static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
+{
+ dma_addr_t dma = d_page->dma;
+ dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma);
+
+ kfree(d_page);
+ d_page = NULL;
+}
+static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
+{
+ struct dma_page *d_page;
+
+ d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
+ if (!d_page)
+ return NULL;
+
+ d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
+ &d_page->dma,
+ pool->gfp_flags);
+ if (d_page->vaddr)
+ d_page->p = virt_to_page(d_page->vaddr);
+ else {
+ kfree(d_page);
+ d_page = NULL;
+ }
+ return d_page;
+}
+static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
+{
+ enum pool_type type = IS_UNDEFINED;
+
+ if (flags & TTM_PAGE_FLAG_DMA32)
+ type |= IS_DMA32;
+ if (cstate == tt_cached)
+ type |= IS_CACHED;
+ else if (cstate == tt_uncached)
+ type |= IS_UC;
+ else
+ type |= IS_WC;
+
+ return type;
+}
+
+static void ttm_pool_update_free_locked(struct dma_pool *pool,
+ unsigned freed_pages)
+{
+ pool->npages_free -= freed_pages;
+ pool->nfrees += freed_pages;
+
+}
+
+/* set memory back to wb and free the pages. */
+static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
+ struct page *pages[], unsigned npages)
+{
+ struct dma_page *d_page, *tmp;
+
+ /* Don't set WB on WB page pool. */
+ if (npages && !(pool->type & IS_CACHED) &&
+ set_pages_array_wb(pages, npages))
+ pr_err("%s: Failed to set %d pages to wb!\n",
+ pool->dev_name, npages);
+
+ list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
+ list_del(&d_page->page_list);
+ __ttm_dma_free_page(pool, d_page);
+ }
+}
+
+static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
+{
+ /* Don't set WB on WB page pool. */
+ if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1))
+ pr_err("%s: Failed to set %d pages to wb!\n",
+ pool->dev_name, 1);
+
+ list_del(&d_page->page_list);
+ __ttm_dma_free_page(pool, d_page);
+}
+
+/*
+ * Free pages from pool.
+ *
+ * To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
+ * number of pages in one go.
+ *
+ * @pool: to free the pages from
+ * @nr_free: If set to true will free all pages in pool
+ * @use_static: Safe to use static buffer
+ **/
+static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
+ bool use_static)
+{
+ static struct page *static_buf[NUM_PAGES_TO_ALLOC];
+ unsigned long irq_flags;
+ struct dma_page *dma_p, *tmp;
+ struct page **pages_to_free;
+ struct list_head d_pages;
+ unsigned freed_pages = 0,
+ npages_to_free = nr_free;
+
+ if (NUM_PAGES_TO_ALLOC < nr_free)
+ npages_to_free = NUM_PAGES_TO_ALLOC;
+#if 0
+ if (nr_free > 1) {
+ pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
+ pool->dev_name, pool->name, current->pid,
+ npages_to_free, nr_free);
+ }
+#endif
+ if (use_static)
+ pages_to_free = static_buf;
+ else
+ pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
+ GFP_KERNEL);
+
+ if (!pages_to_free) {
+ pr_err("%s: Failed to allocate memory for pool free operation\n",
+ pool->dev_name);
+ return 0;
+ }
+ INIT_LIST_HEAD(&d_pages);
+restart:
+ spin_lock_irqsave(&pool->lock, irq_flags);
+
+ /* We picking the oldest ones off the list */
+ list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
+ page_list) {
+ if (freed_pages >= npages_to_free)
+ break;
+
+ /* Move the dma_page from one list to another. */
+ list_move(&dma_p->page_list, &d_pages);
+
+ pages_to_free[freed_pages++] = dma_p->p;
+ /* We can only remove NUM_PAGES_TO_ALLOC at a time. */
+ if (freed_pages >= NUM_PAGES_TO_ALLOC) {
+
+ ttm_pool_update_free_locked(pool, freed_pages);
+ /**
+ * Because changing page caching is costly
+ * we unlock the pool to prevent stalling.
+ */
+ spin_unlock_irqrestore(&pool->lock, irq_flags);
+
+ ttm_dma_pages_put(pool, &d_pages, pages_to_free,
+ freed_pages);
+
+ INIT_LIST_HEAD(&d_pages);
+
+ if (likely(nr_free != FREE_ALL_PAGES))
+ nr_free -= freed_pages;
+
+ if (NUM_PAGES_TO_ALLOC >= nr_free)
+ npages_to_free = nr_free;
+ else
+ npages_to_free = NUM_PAGES_TO_ALLOC;
+
+ freed_pages = 0;
+
+ /* free all so restart the processing */
+ if (nr_free)
+ goto restart;
+
+ /* Not allowed to fall through or break because
+ * following context is inside spinlock while we are
+ * outside here.
+ */
+ goto out;
+
+ }
+ }
+
+ /* remove range of pages from the pool */
+ if (freed_pages) {
+ ttm_pool_update_free_locked(pool, freed_pages);
+ nr_free -= freed_pages;
+ }
+
+ spin_unlock_irqrestore(&pool->lock, irq_flags);
+
+ if (freed_pages)
+ ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
+out:
+ if (pages_to_free != static_buf)
+ kfree(pages_to_free);
+ return nr_free;
+}
+
+static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
+{
+ struct device_pools *p;
+ struct dma_pool *pool;
+
+ if (!dev)
+ return;
+
+ mutex_lock(&_manager->lock);
+ list_for_each_entry_reverse(p, &_manager->pools, pools) {
+ if (p->dev != dev)
+ continue;
+ pool = p->pool;
+ if (pool->type != type)
+ continue;
+
+ list_del(&p->pools);
+ kfree(p);
+ _manager->npools--;
+ break;
+ }
+ list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
+ if (pool->type != type)
+ continue;
+ /* Takes a spinlock.. */
+ /* OK to use static buffer since global mutex is held. */
+ ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, true);
+ WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
+ /* This code path is called after _all_ references to the
+ * struct device has been dropped - so nobody should be
+ * touching it. In case somebody is trying to _add_ we are
+ * guarded by the mutex. */
+ list_del(&pool->pools);
+ kfree(pool);
+ break;
+ }
+ mutex_unlock(&_manager->lock);
+}
+
+/*
+ * On free-ing of the 'struct device' this deconstructor is run.
+ * Albeit the pool might have already been freed earlier.
+ */
+static void ttm_dma_pool_release(struct device *dev, void *res)
+{
+ struct dma_pool *pool = *(struct dma_pool **)res;
+
+ if (pool)
+ ttm_dma_free_pool(dev, pool->type);
+}
+
+static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
+{
+ return *(struct dma_pool **)res == match_data;
+}
+
+static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
+ enum pool_type type)
+{
+ char *n[] = {"wc", "uc", "cached", " dma32", "unknown",};
+ enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED};
+ struct device_pools *sec_pool = NULL;
+ struct dma_pool *pool = NULL, **ptr;
+ unsigned i;
+ int ret = -ENODEV;
+ char *p;
+
+ if (!dev)
+ return NULL;
+
+ ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return NULL;
+
+ ret = -ENOMEM;
+
+ pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
+ dev_to_node(dev));
+ if (!pool)
+ goto err_mem;
+
+ sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
+ dev_to_node(dev));
+ if (!sec_pool)
+ goto err_mem;
+
+ INIT_LIST_HEAD(&sec_pool->pools);
+ sec_pool->dev = dev;
+ sec_pool->pool = pool;
+
+ INIT_LIST_HEAD(&pool->free_list);
+ INIT_LIST_HEAD(&pool->inuse_list);
+ INIT_LIST_HEAD(&pool->pools);
+ spin_lock_init(&pool->lock);
+ pool->dev = dev;
+ pool->npages_free = pool->npages_in_use = 0;
+ pool->nfrees = 0;
+ pool->gfp_flags = flags;
+ pool->size = PAGE_SIZE;
+ pool->type = type;
+ pool->nrefills = 0;
+ p = pool->name;
+ for (i = 0; i < 5; i++) {
+ if (type & t[i]) {
+ p += snprintf(p, sizeof(pool->name) - (p - pool->name),
+ "%s", n[i]);
+ }
+ }
+ *p = 0;
+ /* We copy the name for pr_ calls b/c when dma_pool_destroy is called
+ * - the kobj->name has already been deallocated.*/
+ snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
+ dev_driver_string(dev), dev_name(dev));
+ mutex_lock(&_manager->lock);
+ /* You can get the dma_pool from either the global: */
+ list_add(&sec_pool->pools, &_manager->pools);
+ _manager->npools++;
+ /* or from 'struct device': */
+ list_add(&pool->pools, &dev->dma_pools);
+ mutex_unlock(&_manager->lock);
+
+ *ptr = pool;
+ devres_add(dev, ptr);
+
+ return pool;
+err_mem:
+ devres_free(ptr);
+ kfree(sec_pool);
+ kfree(pool);
+ return ERR_PTR(ret);
+}
+
+static struct dma_pool *ttm_dma_find_pool(struct device *dev,
+ enum pool_type type)
+{
+ struct dma_pool *pool, *tmp, *found = NULL;
+
+ if (type == IS_UNDEFINED)
+ return found;
+
+ /* NB: We iterate on the 'struct dev' which has no spinlock, but
+ * it does have a kref which we have taken. The kref is taken during
+ * graphic driver loading - in the drm_pci_init it calls either
+ * pci_dev_get or pci_register_driver which both end up taking a kref
+ * on 'struct device'.
+ *
+ * On teardown, the graphic drivers end up quiescing the TTM (put_pages)
+ * and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
+ * thing is at that point of time there are no pages associated with the
+ * driver so this function will not be called.
+ */
+ list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) {
+ if (pool->type != type)
+ continue;
+ found = pool;
+ break;
+ }
+ return found;
+}
+
+/*
+ * Free pages the pages that failed to change the caching state. If there
+ * are pages that have changed their caching state already put them to the
+ * pool.
+ */
+static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
+ struct list_head *d_pages,
+ struct page **failed_pages,
+ unsigned cpages)
+{
+ struct dma_page *d_page, *tmp;
+ struct page *p;
+ unsigned i = 0;
+
+ p = failed_pages[0];
+ if (!p)
+ return;
+ /* Find the failed page. */
+ list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
+ if (d_page->p != p)
+ continue;
+ /* .. and then progress over the full list. */
+ list_del(&d_page->page_list);
+ __ttm_dma_free_page(pool, d_page);
+ if (++i < cpages)
+ p = failed_pages[i];
+ else
+ break;
+ }
+
+}
+
+/*
+ * Allocate 'count' pages, and put 'need' number of them on the
+ * 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
+ * The full list of pages should also be on 'd_pages'.
+ * We return zero for success, and negative numbers as errors.
+ */
+static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
+ struct list_head *d_pages,
+ unsigned count)
+{
+ struct page **caching_array;
+ struct dma_page *dma_p;
+ struct page *p;
+ int r = 0;
+ unsigned i, cpages;
+ unsigned max_cpages = min(count,
+ (unsigned)(PAGE_SIZE/sizeof(struct page *)));
+
+ /* allocate array for page caching change */
+ caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
+
+ if (!caching_array) {
+ pr_err("%s: Unable to allocate table for new pages\n",
+ pool->dev_name);
+ return -ENOMEM;
+ }
+
+ if (count > 1) {
+ pr_debug("%s: (%s:%d) Getting %d pages\n",
+ pool->dev_name, pool->name, current->pid, count);
+ }
+
+ for (i = 0, cpages = 0; i < count; ++i) {
+ dma_p = __ttm_dma_alloc_page(pool);
+ if (!dma_p) {
+ pr_err("%s: Unable to get page %u\n",
+ pool->dev_name, i);
+
+ /* store already allocated pages in the pool after
+ * setting the caching state */
+ if (cpages) {
+ r = ttm_set_pages_caching(pool, caching_array,
+ cpages);
+ if (r)
+ ttm_dma_handle_caching_state_failure(
+ pool, d_pages, caching_array,
+ cpages);
+ }
+ r = -ENOMEM;
+ goto out;
+ }
+ p = dma_p->p;
+#ifdef CONFIG_HIGHMEM
+ /* gfp flags of highmem page should never be dma32 so we
+ * we should be fine in such case
+ */
+ if (!PageHighMem(p))
+#endif
+ {
+ caching_array[cpages++] = p;
+ if (cpages == max_cpages) {
+ /* Note: Cannot hold the spinlock */
+ r = ttm_set_pages_caching(pool, caching_array,
+ cpages);
+ if (r) {
+ ttm_dma_handle_caching_state_failure(
+ pool, d_pages, caching_array,
+ cpages);
+ goto out;
+ }
+ cpages = 0;
+ }
+ }
+ list_add(&dma_p->page_list, d_pages);
+ }
+
+ if (cpages) {
+ r = ttm_set_pages_caching(pool, caching_array, cpages);
+ if (r)
+ ttm_dma_handle_caching_state_failure(pool, d_pages,
+ caching_array, cpages);
+ }
+out:
+ kfree(caching_array);
+ return r;
+}
+
+/*
+ * @return count of pages still required to fulfill the request.
+ */
+static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
+ unsigned long *irq_flags)
+{
+ unsigned count = _manager->options.small;
+ int r = pool->npages_free;
+
+ if (count > pool->npages_free) {
+ struct list_head d_pages;
+
+ INIT_LIST_HEAD(&d_pages);
+
+ spin_unlock_irqrestore(&pool->lock, *irq_flags);
+
+ /* Returns how many more are neccessary to fulfill the
+ * request. */
+ r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
+
+ spin_lock_irqsave(&pool->lock, *irq_flags);
+ if (!r) {
+ /* Add the fresh to the end.. */
+ list_splice(&d_pages, &pool->free_list);
+ ++pool->nrefills;
+ pool->npages_free += count;
+ r = count;
+ } else {
+ struct dma_page *d_page;
+ unsigned cpages = 0;
+
+ pr_err("%s: Failed to fill %s pool (r:%d)!\n",
+ pool->dev_name, pool->name, r);
+
+ list_for_each_entry(d_page, &d_pages, page_list) {
+ cpages++;
+ }
+ list_splice_tail(&d_pages, &pool->free_list);
+ pool->npages_free += cpages;
+ r = cpages;
+ }
+ }
+ return r;
+}
+
+/*
+ * @return count of pages still required to fulfill the request.
+ * The populate list is actually a stack (not that is matters as TTM
+ * allocates one page at a time.
+ */
+static int ttm_dma_pool_get_pages(struct dma_pool *pool,
+ struct ttm_dma_tt *ttm_dma,
+ unsigned index)
+{
+ struct dma_page *d_page;
+ struct ttm_tt *ttm = &ttm_dma->ttm;
+ unsigned long irq_flags;
+ int count, r = -ENOMEM;
+
+ spin_lock_irqsave(&pool->lock, irq_flags);
+ count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
+ if (count) {
+ d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
+ ttm->pages[index] = d_page->p;
+ ttm_dma->cpu_address[index] = d_page->vaddr;
+ ttm_dma->dma_address[index] = d_page->dma;
+ list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
+ r = 0;
+ pool->npages_in_use += 1;
+ pool->npages_free -= 1;
+ }
+ spin_unlock_irqrestore(&pool->lock, irq_flags);
+ return r;
+}
+
+/*
+ * On success pages list will hold count number of correctly
+ * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
+ */
+int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
+{
+ struct ttm_tt *ttm = &ttm_dma->ttm;
+ struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
+ struct dma_pool *pool;
+ enum pool_type type;
+ unsigned i;
+ gfp_t gfp_flags;
+ int ret;
+
+ if (ttm->state != tt_unpopulated)
+ return 0;
+
+ type = ttm_to_type(ttm->page_flags, ttm->caching_state);
+ if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
+ gfp_flags = GFP_USER | GFP_DMA32;
+ else
+ gfp_flags = GFP_HIGHUSER;
+ if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
+ gfp_flags |= __GFP_ZERO;
+
+ pool = ttm_dma_find_pool(dev, type);
+ if (!pool) {
+ pool = ttm_dma_pool_init(dev, gfp_flags, type);
+ if (IS_ERR_OR_NULL(pool)) {
+ return -ENOMEM;
+ }
+ }
+
+ INIT_LIST_HEAD(&ttm_dma->pages_list);
+ for (i = 0; i < ttm->num_pages; ++i) {
+ ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
+ if (ret != 0) {
+ ttm_dma_unpopulate(ttm_dma, dev);
+ return -ENOMEM;
+ }
+
+ ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
+ false, false);
+ if (unlikely(ret != 0)) {
+ ttm_dma_unpopulate(ttm_dma, dev);
+ return -ENOMEM;
+ }
+ }
+
+ if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
+ ret = ttm_tt_swapin(ttm);
+ if (unlikely(ret != 0)) {
+ ttm_dma_unpopulate(ttm_dma, dev);
+ return ret;
+ }
+ }
+
+ ttm->state = tt_unbound;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ttm_dma_populate);
+
+/* Put all pages in pages list to correct pool to wait for reuse */
+void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
+{
+ struct ttm_tt *ttm = &ttm_dma->ttm;
+ struct dma_pool *pool;
+ struct dma_page *d_page, *next;
+ enum pool_type type;
+ bool is_cached = false;
+ unsigned count = 0, i, npages = 0;
+ unsigned long irq_flags;
+
+ type = ttm_to_type(ttm->page_flags, ttm->caching_state);
+ pool = ttm_dma_find_pool(dev, type);
+ if (!pool)
+ return;
+
+ is_cached = (ttm_dma_find_pool(pool->dev,
+ ttm_to_type(ttm->page_flags, tt_cached)) == pool);
+
+ /* make sure pages array match list and count number of pages */
+ list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) {
+ ttm->pages[count] = d_page->p;
+ count++;
+ }
+
+ spin_lock_irqsave(&pool->lock, irq_flags);
+ pool->npages_in_use -= count;
+ if (is_cached) {
+ pool->nfrees += count;
+ } else {
+ pool->npages_free += count;
+ list_splice(&ttm_dma->pages_list, &pool->free_list);
+ npages = count;
+ if (pool->npages_free > _manager->options.max_size) {
+ npages = pool->npages_free - _manager->options.max_size;
+ /* free at least NUM_PAGES_TO_ALLOC number of pages
+ * to reduce calls to set_memory_wb */
+ if (npages < NUM_PAGES_TO_ALLOC)
+ npages = NUM_PAGES_TO_ALLOC;
+ }
+ }
+ spin_unlock_irqrestore(&pool->lock, irq_flags);
+
+ if (is_cached) {
+ list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) {
+ ttm_mem_global_free_page(ttm->glob->mem_glob,
+ d_page->p);
+ ttm_dma_page_put(pool, d_page);
+ }
+ } else {
+ for (i = 0; i < count; i++) {
+ ttm_mem_global_free_page(ttm->glob->mem_glob,
+ ttm->pages[i]);
+ }
+ }
+
+ INIT_LIST_HEAD(&ttm_dma->pages_list);
+ for (i = 0; i < ttm->num_pages; i++) {
+ ttm->pages[i] = NULL;
+ ttm_dma->cpu_address[i] = 0;
+ ttm_dma->dma_address[i] = 0;
+ }
+
+ /* shrink pool if necessary (only on !is_cached pools)*/
+ if (npages)
+ ttm_dma_page_pool_free(pool, npages, false);
+ ttm->state = tt_unpopulated;
+}
+EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
+
+/**
+ * Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
+ * shrinkers
+ */
+static unsigned long
+ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ static unsigned start_pool;
+ unsigned idx = 0;
+ unsigned pool_offset;
+ unsigned shrink_pages = sc->nr_to_scan;
+ struct device_pools *p;
+ unsigned long freed = 0;
+
+ if (list_empty(&_manager->pools))
+ return SHRINK_STOP;
+
+ if (!mutex_trylock(&_manager->lock))
+ return SHRINK_STOP;
+ if (!_manager->npools)
+ goto out;
+ pool_offset = ++start_pool % _manager->npools;
+ list_for_each_entry(p, &_manager->pools, pools) {
+ unsigned nr_free;
+
+ if (!p->dev)
+ continue;
+ if (shrink_pages == 0)
+ break;
+ /* Do it in round-robin fashion. */
+ if (++idx < pool_offset)
+ continue;
+ nr_free = shrink_pages;
+ /* OK to use static buffer since global mutex is held. */
+ shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free, true);
+ freed += nr_free - shrink_pages;
+
+ pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
+ p->pool->dev_name, p->pool->name, current->pid,
+ nr_free, shrink_pages);
+ }
+out:
+ mutex_unlock(&_manager->lock);
+ return freed;
+}
+
+static unsigned long
+ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ struct device_pools *p;
+ unsigned long count = 0;
+
+ if (!mutex_trylock(&_manager->lock))
+ return 0;
+ list_for_each_entry(p, &_manager->pools, pools)
+ count += p->pool->npages_free;
+ mutex_unlock(&_manager->lock);
+ return count;
+}
+
+static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
+{
+ manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count;
+ manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
+ manager->mm_shrink.seeks = 1;
+ register_shrinker(&manager->mm_shrink);
+}
+
+static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
+{
+ unregister_shrinker(&manager->mm_shrink);
+}
+
+int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
+{
+ int ret = -ENOMEM;
+
+ WARN_ON(_manager);
+
+ pr_info("Initializing DMA pool allocator\n");
+
+ _manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
+ if (!_manager)
+ goto err;
+
+ mutex_init(&_manager->lock);
+ INIT_LIST_HEAD(&_manager->pools);
+
+ _manager->options.max_size = max_pages;
+ _manager->options.small = SMALL_ALLOCATION;
+ _manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
+
+ /* This takes care of auto-freeing the _manager */
+ ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
+ &glob->kobj, "dma_pool");
+ if (unlikely(ret != 0)) {
+ kobject_put(&_manager->kobj);
+ goto err;
+ }
+ ttm_dma_pool_mm_shrink_init(_manager);
+ return 0;
+err:
+ return ret;
+}
+
+void ttm_dma_page_alloc_fini(void)
+{
+ struct device_pools *p, *t;
+
+ pr_info("Finalizing DMA pool allocator\n");
+ ttm_dma_pool_mm_shrink_fini(_manager);
+
+ list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
+ dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
+ current->pid);
+ WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
+ ttm_dma_pool_match, p->pool));
+ ttm_dma_free_pool(p->dev, p->pool->type);
+ }
+ kobject_put(&_manager->kobj);
+ _manager = NULL;
+}
+
+int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
+{
+ struct device_pools *p;
+ struct dma_pool *pool = NULL;
+ char *h[] = {"pool", "refills", "pages freed", "inuse", "available",
+ "name", "virt", "busaddr"};
+
+ if (!_manager) {
+ seq_printf(m, "No pool allocator running.\n");
+ return 0;
+ }
+ seq_printf(m, "%13s %12s %13s %8s %8s %8s\n",
+ h[0], h[1], h[2], h[3], h[4], h[5]);
+ mutex_lock(&_manager->lock);
+ list_for_each_entry(p, &_manager->pools, pools) {
+ struct device *dev = p->dev;
+ if (!dev)
+ continue;
+ pool = p->pool;
+ seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
+ pool->name, pool->nrefills,
+ pool->nfrees, pool->npages_in_use,
+ pool->npages_free,
+ pool->dev_name);
+ }
+ mutex_unlock(&_manager->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);
+
+#endif
Code Review / kvmfornfv.git / blobdiff