2 files changed, 30 insertions, 21 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index 09874d695188..025c429050c0 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -297,11 +297,12 @@ static void ttm_pool_update_free_locked(struct ttm_page_pool *pool,
  *
  * @pool: to free the pages from
  * @free_all: If set to true will free all pages in pool
- * @gfp: GFP flags.
+ * @use_static: Safe to use static buffer
  **/
 static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free,
-                              gfp_t gfp)
+                              bool use_static)
 {
+        static struct page *static_buf[NUM_PAGES_TO_ALLOC];
         unsigned long irq_flags;
         struct page *p;
         struct page **pages_to_free;
@@ -311,7 +312,11 @@ static int ttm_page_pool_free(struct ttm_page_pool *pool, unsigned nr_free,
         if (NUM_PAGES_TO_ALLOC < nr_free)
                 npages_to_free = NUM_PAGES_TO_ALLOC;
 
-        pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), gfp);
+        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("Failed to allocate memory for pool free operation\n");
                 return 0;
@@ -374,7 +379,8 @@ restart:
         if (freed_pages)
                 ttm_pages_put(pages_to_free, freed_pages);
 out:
-        kfree(pages_to_free);
+        if (pages_to_free != static_buf)
+                kfree(pages_to_free);
         return nr_free;
 }
 
@@ -383,8 +389,6 @@ out:
  *
  * XXX: (dchinner) Deadlock warning!
  *
- * We need to pass sc->gfp_mask to ttm_page_pool_free().
- *
  * This code is crying out for a shrinker per pool....
  */
 static unsigned long
@@ -407,8 +411,8 @@ ttm_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
                 if (shrink_pages == 0)
                         break;
                 pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
-                shrink_pages = ttm_page_pool_free(pool, nr_free,
-                                                  sc->gfp_mask);
+                /* OK to use static buffer since global mutex is held. */
+                shrink_pages = ttm_page_pool_free(pool, nr_free, true);
                 freed += nr_free - shrink_pages;
         }
         mutex_unlock(&lock);
@@ -710,7 +714,7 @@ static void ttm_put_pages(struct page **pages, unsigned npages, int flags,
         }
         spin_unlock_irqrestore(&pool->lock, irq_flags);
         if (npages)
-                ttm_page_pool_free(pool, npages, GFP_KERNEL);
+                ttm_page_pool_free(pool, npages, false);
 }
 
 /*
@@ -849,9 +853,9 @@ void ttm_page_alloc_fini(void)
         pr_info("Finalizing pool allocator\n");
         ttm_pool_mm_shrink_fini(_manager);
 
+        /* OK to use static buffer since global mutex is no longer used. */
         for (i = 0; i < NUM_POOLS; ++i)
-                ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES,
-                                   GFP_KERNEL);
+                ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES, true);
 
         kobject_put(&_manager->kobj);
         _manager = NULL;
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
index c96db433f8af..01e1d27eb078 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
@@ -411,11 +411,12 @@ static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
  *
  * @pool: to free the pages from
  * @nr_free: If set to true will free all pages in pool
- * @gfp: GFP flags.
+ * @use_static: Safe to use static buffer
  **/
 static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
-                                       gfp_t gfp)
+                                       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;
@@ -432,7 +433,11 @@ static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free,
                          npages_to_free, nr_free);
         }
 #endif
-        pages_to_free = kmalloc(npages_to_free * sizeof(struct page *), gfp);
+        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",
@@ -502,7 +507,8 @@ restart:
         if (freed_pages)
                 ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
 out:
-        kfree(pages_to_free);
+        if (pages_to_free != static_buf)
+                kfree(pages_to_free);
         return nr_free;
 }
 
@@ -531,7 +537,8 @@ static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
                 if (pool->type != type)
                         continue;
                 /* Takes a spinlock.. */
-                ttm_dma_page_pool_free(pool, FREE_ALL_PAGES, GFP_KERNEL);
+                /* 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
@@ -986,7 +993,7 @@ void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 
         /* shrink pool if necessary (only on !is_cached pools)*/
         if (npages)
-                ttm_dma_page_pool_free(pool, npages, GFP_KERNEL);
+                ttm_dma_page_pool_free(pool, npages, false);
         ttm->state = tt_unpopulated;
 }
 EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
@@ -996,8 +1003,6 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
  *
  * XXX: (dchinner) Deadlock warning!
  *
- * We need to pass sc->gfp_mask to ttm_dma_page_pool_free().
- *
  * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
  * shrinkers
  */
@@ -1030,8 +1035,8 @@ ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
                 if (++idx < pool_offset)
                         continue;
                 nr_free = shrink_pages;
-                shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free,
-                                                      sc->gfp_mask);
+                /* 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",