[PATCH 3/3] drm/ttm: add transparent huge page support for DMA allocations
Christian König
deathsimple at vodafone.de
Thu Jul 13 13:56:09 UTC 2017
From: Christian König <christian.koenig at amd.com>
Try to allocate huge pages when it makes sense.
Signed-off-by: Christian König <christian.koenig at amd.com>
---
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 217 ++++++++++++++++++++++++-------
1 file changed, 169 insertions(+), 48 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index 2081e20..e51d3fd 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -57,21 +57,25 @@
#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 seven 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):
+ * - 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.
@@ -111,13 +115,14 @@ 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;
};
@@ -316,7 +321,8 @@ 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;
@@ -324,19 +330,22 @@ 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;
@@ -368,11 +377,40 @@ 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))
@@ -385,17 +423,6 @@ 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.
*
@@ -564,8 +591,8 @@ 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;
@@ -602,11 +629,18 @@ 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)
+#if 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]);
@@ -710,7 +744,7 @@ 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 *)));
@@ -748,28 +782,32 @@ 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) {
@@ -857,6 +895,26 @@ 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).
@@ -865,6 +923,7 @@ 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;
@@ -873,26 +932,61 @@ 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);
+
+#if 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);
@@ -905,6 +999,9 @@ 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)) {
@@ -928,10 +1025,33 @@ 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);
+
+#if 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;
@@ -940,6 +1060,7 @@ 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++;
--
2.7.4
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