drm/ttm: add VADDR_FLAG_UPDATED_COUNT to correctly update dma_page global count

add this for correctly updating global mem count in ttm_mem_zone.
before that when ttm_mem_global_alloc_page fails, we would update all
dma_page's global mem count in ttm_dma->pages_list. but actually here
we should not update for the last dma_page.

v2: only the update of last dma_page is not right
v3: use lower bits of dma_page vaddr

Signed-off-by: Roger He <Hongbo.He@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index c7f01a4d924c4cd68caf4445b867bd5de5cd25b9..a88051552acee7c90a526486a0632f1b2be1f98a 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -61,6 +61,7 @@
 #define SMALL_ALLOCATION               4
 #define FREE_ALL_PAGES                 (~0U)
 #define VADDR_FLAG_HUGE_POOL           1UL
+#define VADDR_FLAG_UPDATED_COUNT       2UL
 
 enum pool_type {
        IS_UNDEFINED    = 0,
@@ -874,18 +875,18 @@ static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
 }
 
 /*
- * @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.
+ * return dma_page pointer if success, otherwise NULL.
  */
-static int ttm_dma_pool_get_pages(struct dma_pool *pool,
+static struct dma_page *ttm_dma_pool_get_pages(struct dma_pool *pool,
                                  struct ttm_dma_tt *ttm_dma,
                                  unsigned index)
 {
-       struct dma_page *d_page;
+       struct dma_page *d_page = NULL;
        struct ttm_tt *ttm = &ttm_dma->ttm;
        unsigned long irq_flags;
-       int count, r = -ENOMEM;
+       int count;
 
        spin_lock_irqsave(&pool->lock, irq_flags);
        count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
@@ -894,12 +895,11 @@ static int ttm_dma_pool_get_pages(struct dma_pool *pool,
                ttm->pages[index] = d_page->p;
                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;
+       return d_page;
 }
 
 static gfp_t ttm_dma_pool_gfp_flags(struct ttm_dma_tt *ttm_dma, bool huge)
@@ -934,6 +934,7 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
        struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
        unsigned long num_pages = ttm->num_pages;
        struct dma_pool *pool;
+       struct dma_page *d_page;
        enum pool_type type;
        unsigned i;
        int ret;
@@ -962,8 +963,8 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
        while (num_pages >= HPAGE_PMD_NR) {
                unsigned j;
 
-               ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
-               if (ret != 0)
+               d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
+               if (!d_page)
                        break;
 
                ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
@@ -973,6 +974,7 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev,
                        return -ENOMEM;
                }
 
+               d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
                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] +
@@ -996,8 +998,8 @@ skip_huge:
        }
 
        while (num_pages) {
-               ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
-               if (ret != 0) {
+               d_page = ttm_dma_pool_get_pages(pool, ttm_dma, i);
+               if (!d_page) {
                        ttm_dma_unpopulate(ttm_dma, dev);
                        return -ENOMEM;
                }
@@ -1009,6 +1011,7 @@ skip_huge:
                        return -ENOMEM;
                }
 
+               d_page->vaddr |= VADDR_FLAG_UPDATED_COUNT;
                ++i;
                --num_pages;
        }
@@ -1049,8 +1052,11 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
                                continue;
 
                        count++;
-                       ttm_mem_global_free_page(ttm->glob->mem_glob,
-                                                d_page->p, pool->size);
+                       if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
+                               ttm_mem_global_free_page(ttm->glob->mem_glob,
+                                                        d_page->p, pool->size);
+                               d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
+                       }
                        ttm_dma_page_put(pool, d_page);
                }
 
@@ -1070,9 +1076,19 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 
        /* 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) {
+       list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list,
+                                page_list) {
                ttm->pages[count] = d_page->p;
                count++;
+
+               if (d_page->vaddr & VADDR_FLAG_UPDATED_COUNT) {
+                       ttm_mem_global_free_page(ttm->glob->mem_glob,
+                                                d_page->p, pool->size);
+                       d_page->vaddr &= ~VADDR_FLAG_UPDATED_COUNT;
+               }
+
+               if (is_cached)
+                       ttm_dma_page_put(pool, d_page);
        }
 
        spin_lock_irqsave(&pool->lock, irq_flags);
@@ -1092,19 +1108,6 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
        }
        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, pool->size);
-                       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], pool->size);
-               }
-       }
-
        INIT_LIST_HEAD(&ttm_dma->pages_list);
        for (i = 0; i < ttm->num_pages; i++) {
                ttm->pages[i] = NULL;