drm/ttm: add transparent huge page support for DMA allocations v2
authorChristian König <christian.koenig@amd.com>
Thu, 6 Jul 2017 07:59:43 +0000 (09:59 +0200)
committerAlex Deucher <alexander.deucher@amd.com>
Fri, 6 Oct 2017 21:44:18 +0000 (17:44 -0400)
Try to allocate huge pages when it makes sense.

v2: fix comment and use ifdef

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c

index 53626578004c4872346cae14560b0c845c97a669..e5ef10d347485987cd694a32be4f2442702c55c7 100644 (file)
 #define NUM_PAGES_TO_ALLOC             (PAGE_SIZE/sizeof(struct page *))
 #define SMALL_ALLOCATION               4
 #define FREE_ALL_PAGES                 (~0U)
+#define VADDR_FLAG_HUGE_POOL           1UL
 
 enum pool_type {
        IS_UNDEFINED    = 0,
        IS_WC           = 1 << 1,
        IS_UC           = 1 << 2,
        IS_CACHED       = 1 << 3,
-       IS_DMA32        = 1 << 4
+       IS_DMA32        = 1 << 4,
+       IS_HUGE         = 1 << 5
 };
 
 /*
- * The pool structure. There are usually six pools:
+ * The pool structure. There are up to nine pools:
  *  - generic (not restricted to DMA32):
  *      - write combined, uncached, cached.
  *  - dma32 (up to 2^32 - so up 4GB):
  *      - write combined, uncached, cached.
+ *  - huge (not restricted to DMA32):
+ *      - 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.
@@ -114,13 +118,14 @@ struct dma_pool {
  * 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
+ * @vaddr: The virtual address of the page and a flag if the page belongs to a
+ * huge pool
  * @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;
+       unsigned long vaddr;
        struct page *p;
        dma_addr_t dma;
 };
@@ -319,7 +324,8 @@ static int ttm_set_pages_caching(struct dma_pool *pool,
 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);
+       d_page->vaddr &= ~VADDR_FLAG_HUGE_POOL;
+       dma_free_coherent(pool->dev, pool->size, (void *)d_page->vaddr, dma);
 
        kfree(d_page);
        d_page = NULL;
@@ -327,19 +333,22 @@ static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
 static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
 {
        struct dma_page *d_page;
+       void *vaddr;
 
        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) {
-               if (is_vmalloc_addr(d_page->vaddr))
-                       d_page->p = vmalloc_to_page(d_page->vaddr);
+       vaddr = dma_alloc_coherent(pool->dev, pool->size, &d_page->dma,
+                                  pool->gfp_flags);
+       if (vaddr) {
+               if (is_vmalloc_addr(vaddr))
+                       d_page->p = vmalloc_to_page(vaddr);
                else
-                       d_page->p = virt_to_page(d_page->vaddr);
+                       d_page->p = virt_to_page(vaddr);
+               d_page->vaddr = (unsigned long)vaddr;
+               if (pool->type & IS_HUGE)
+                       d_page->vaddr |= VADDR_FLAG_HUGE_POOL;
        } else {
                kfree(d_page);
                d_page = NULL;
@@ -371,11 +380,40 @@ static void ttm_pool_update_free_locked(struct dma_pool *pool,
 }
 
 /* set memory back to wb and free the pages. */
+static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
+{
+       struct page *page = d_page->p;
+       unsigned i, num_pages;
+       int ret;
+
+       /* Don't set WB on WB page pool. */
+       if (!(pool->type & IS_CACHED)) {
+               num_pages = pool->size / PAGE_SIZE;
+               for (i = 0; i < num_pages; ++i, ++page) {
+                       ret = set_pages_array_wb(&page, 1);
+                       if (ret) {
+                               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);
+}
+
 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;
 
+       if (pool->type & IS_HUGE) {
+               list_for_each_entry_safe(d_page, tmp, d_pages, page_list)
+                       ttm_dma_page_put(pool, d_page);
+
+               return;
+       }
+
        /* Don't set WB on WB page pool. */
        if (npages && !(pool->type & IS_CACHED) &&
            set_pages_array_wb(pages, npages))
@@ -388,17 +426,6 @@ static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
        }
 }
 
-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.
  *
@@ -567,8 +594,8 @@ static int ttm_dma_pool_match(struct device *dev, void *res, void *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};
+       const char *n[] = {"wc", "uc", "cached", " dma32", "huge"};
+       enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_HUGE};
        struct device_pools *sec_pool = NULL;
        struct dma_pool *pool = NULL, **ptr;
        unsigned i;
@@ -605,11 +632,18 @@ static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
        pool->npages_free = pool->npages_in_use = 0;
        pool->nfrees = 0;
        pool->gfp_flags = flags;
-       pool->size = PAGE_SIZE;
+       if (type & IS_HUGE)
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+               pool->size = HPAGE_PMD_SIZE;
+#else
+               BUG();
+#endif
+       else
+               pool->size = PAGE_SIZE;
        pool->type = type;
        pool->nrefills = 0;
        p = pool->name;
-       for (i = 0; i < 5; i++) {
+       for (i = 0; i < ARRAY_SIZE(t); i++) {
                if (type & t[i]) {
                        p += snprintf(p, sizeof(pool->name) - (p - pool->name),
                                      "%s", n[i]);
@@ -713,7 +747,7 @@ static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
        struct dma_page *dma_p;
        struct page *p;
        int r = 0;
-       unsigned i, cpages;
+       unsigned i, j, npages, cpages;
        unsigned max_cpages = min(count,
                        (unsigned)(PAGE_SIZE/sizeof(struct page *)));
 
@@ -751,28 +785,32 @@ static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
                        goto out;
                }
                p = dma_p->p;
+               list_add(&dma_p->page_list, d_pages);
+
 #ifdef CONFIG_HIGHMEM
                /* gfp flags of highmem page should never be dma32 so we
                 * we should be fine in such case
                 */
-               if (!PageHighMem(p))
+               if (PageHighMem(p))
+                       continue;
 #endif
-               {
-                       caching_array[cpages++] = p;
+
+               npages = pool->size / PAGE_SIZE;
+               for (j = 0; j < npages; ++j) {
+                       caching_array[cpages++] = p + j;
                        if (cpages == max_cpages) {
                                /* Note: Cannot hold the spinlock */
                                r = ttm_set_pages_caching(pool, caching_array,
-                                                cpages);
+                                                         cpages);
                                if (r) {
                                        ttm_dma_handle_caching_state_failure(
-                                               pool, d_pages, caching_array,
-                                               cpages);
+                                            pool, d_pages, caching_array,
+                                            cpages);
                                        goto out;
                                }
                                cpages = 0;
                        }
                }
-               list_add(&dma_p->page_list, d_pages);
        }
 
        if (cpages) {
@@ -860,6 +898,26 @@ static int ttm_dma_pool_get_pages(struct dma_pool *pool,
        return r;
 }
 
+static gfp_t ttm_dma_pool_gfp_flags(struct ttm_dma_tt *ttm_dma, bool huge)
+{
+       struct ttm_tt *ttm = &ttm_dma->ttm;
+       gfp_t gfp_flags;
+
+       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;
+
+       if (huge) {
+               gfp_flags |= GFP_TRANSHUGE;
+               gfp_flags &= ~__GFP_MOVABLE;
+       }
+
+       return gfp_flags;
+}
+
 /*
  * On success pages list will hold count number of correctly
  * cached pages. On failure will hold the negative return value (-ENOMEM, etc).
@@ -868,6 +926,7 @@ 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;
+       unsigned long num_pages = ttm->num_pages;
        struct dma_pool *pool;
        enum pool_type type;
        unsigned i;
@@ -876,26 +935,61 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
        if (ttm->state != tt_unpopulated)
                return 0;
 
+       INIT_LIST_HEAD(&ttm_dma->pages_list);
+       i = 0;
+
        type = ttm_to_type(ttm->page_flags, ttm->caching_state);
-       pool = ttm_dma_find_pool(dev, type);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
+               goto skip_huge;
+
+       pool = ttm_dma_find_pool(dev, type | IS_HUGE);
        if (!pool) {
-               gfp_t gfp_flags;
+               gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, true);
 
-               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_pool_init(dev, gfp_flags, type | IS_HUGE);
+               if (IS_ERR_OR_NULL(pool))
+                       goto skip_huge;
+       }
 
-               pool = ttm_dma_pool_init(dev, gfp_flags, type);
-               if (IS_ERR_OR_NULL(pool)) {
+       while (num_pages >= HPAGE_PMD_NR) {
+               unsigned j;
+
+               ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
+               if (ret != 0)
+                       break;
+
+               ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
+                                               pool->size);
+               if (unlikely(ret != 0)) {
+                       ttm_dma_unpopulate(ttm_dma, dev);
                        return -ENOMEM;
                }
+
+               for (j = i + 1; j < (i + HPAGE_PMD_NR); ++j) {
+                       ttm->pages[j] = ttm->pages[j - 1] + 1;
+                       ttm_dma->dma_address[j] = ttm_dma->dma_address[j - 1] +
+                               PAGE_SIZE;
+               }
+
+               i += HPAGE_PMD_NR;
+               num_pages -= HPAGE_PMD_NR;
        }
 
-       INIT_LIST_HEAD(&ttm_dma->pages_list);
-       for (i = 0; i < ttm->num_pages; ++i) {
+skip_huge:
+#endif
+
+       pool = ttm_dma_find_pool(dev, type);
+       if (!pool) {
+               gfp_t gfp_flags = ttm_dma_pool_gfp_flags(ttm_dma, false);
+
+               pool = ttm_dma_pool_init(dev, gfp_flags, type);
+               if (IS_ERR_OR_NULL(pool))
+                       return -ENOMEM;
+       }
+
+       while (num_pages) {
                ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
                if (ret != 0) {
                        ttm_dma_unpopulate(ttm_dma, dev);
@@ -908,6 +1002,9 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
                        ttm_dma_unpopulate(ttm_dma, dev);
                        return -ENOMEM;
                }
+
+               ++i;
+               --num_pages;
        }
 
        if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
@@ -931,10 +1028,33 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
        struct dma_page *d_page, *next;
        enum pool_type type;
        bool is_cached = false;
-       unsigned count = 0, i, npages = 0;
+       unsigned count, i, npages = 0;
        unsigned long irq_flags;
 
        type = ttm_to_type(ttm->page_flags, ttm->caching_state);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       pool = ttm_dma_find_pool(dev, type | IS_HUGE);
+       if (pool) {
+               count = 0;
+               list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
+                                        page_list) {
+                       if (!(d_page->vaddr & VADDR_FLAG_HUGE_POOL))
+                               continue;
+
+                       count++;
+                       ttm_mem_global_free_page(ttm->glob->mem_glob,
+                                                d_page->p, pool->size);
+                       ttm_dma_page_put(pool, d_page);
+               }
+
+               spin_lock_irqsave(&pool->lock, irq_flags);
+               pool->npages_in_use -= count;
+               pool->nfrees += count;
+               spin_unlock_irqrestore(&pool->lock, irq_flags);
+       }
+#endif
+
        pool = ttm_dma_find_pool(dev, type);
        if (!pool)
                return;
@@ -943,6 +1063,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
                     ttm_to_type(ttm->page_flags, tt_cached)) == pool);
 
        /* make sure pages array match list and count number of pages */
+       count = 0;
        list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) {
                ttm->pages[count] = d_page->p;
                count++;