2 files changed, 22 insertions, 14 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index c9f2a840..d66e46b8 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -902,7 +902,8 @@ static int gk20a_init_vidmem(struct mm_gk20a *mm)
         mm->vidmem.bootstrap_base = bootstrap_base;
         mm->vidmem.bootstrap_size = bootstrap_size;
 
-        INIT_WORK(&mm->vidmem_clear_mem_worker, gk20a_vidmem_clear_mem_worker);
+        INIT_WORK(&mm->vidmem.clear_mem_worker, gk20a_vidmem_clear_mem_worker);
+        atomic_set(&mm->vidmem.clears_pending, 0);
         INIT_LIST_HEAD(&mm->vidmem.clear_list_head);
         mutex_init(&mm->vidmem.clear_list_mutex);
 
@@ -2982,10 +2983,10 @@ int gk20a_gmmu_alloc_attr_vid_at(struct gk20a *g, enum dma_attr attr,
 #if defined(CONFIG_GK20A_VIDMEM)
         u64 addr;
         int err;
-        bool clear_list_empty;
         struct gk20a_allocator *vidmem_alloc = g->mm.vidmem.cleared ?
                 &g->mm.vidmem.allocator :
                 &g->mm.vidmem.bootstrap_allocator;
+        int before_pending;
 
         gk20a_dbg_fn("");
 
@@ -2996,16 +2997,19 @@ int gk20a_gmmu_alloc_attr_vid_at(struct gk20a *g, enum dma_attr attr,
          * are not done anyway */
         WARN_ON(attr != 0 && attr != DMA_ATTR_NO_KERNEL_MAPPING);
 
+        mutex_lock(&g->mm.vidmem.clear_list_mutex);
+        before_pending = atomic_read(&g->mm.vidmem.clears_pending);
         addr = __gk20a_gmmu_alloc(vidmem_alloc, at, size);
+        mutex_unlock(&g->mm.vidmem.clear_list_mutex);
         if (!addr) {
-                mutex_lock(&g->mm.vidmem.clear_list_mutex);
-                clear_list_empty = list_empty(&g->mm.vidmem.clear_list_head);
-                mutex_unlock(&g->mm.vidmem.clear_list_mutex);
-
-                if (clear_list_empty)
-                        return -ENOMEM;
-                else
+                /*
+                 * If memory is known to be freed soon, let the user know that
+                 * it may be available after a while.
+                 */
+                if (before_pending)
                         return -EAGAIN;
+                else
+                        return -ENOMEM;
         }
 
         if (at)
@@ -3057,11 +3061,12 @@ static void gk20a_gmmu_free_attr_vid(struct gk20a *g, enum dma_attr attr,
                 was_empty = list_empty(&g->mm.vidmem.clear_list_head);
                 list_add_tail(&mem->clear_list_entry,
                               &g->mm.vidmem.clear_list_head);
+                atomic_inc(&g->mm.vidmem.clears_pending);
                 mutex_unlock(&g->mm.vidmem.clear_list_mutex);
 
                 if (was_empty) {
-                        cancel_work_sync(&g->mm.vidmem_clear_mem_worker);
-                        schedule_work(&g->mm.vidmem_clear_mem_worker);
+                        cancel_work_sync(&g->mm.vidmem.clear_mem_worker);
+                        schedule_work(&g->mm.vidmem.clear_mem_worker);
                 }
         } else {
                 gk20a_memset(g, mem, 0, 0, mem->size);
@@ -3136,7 +3141,7 @@ static struct mem_desc *get_pending_mem_desc(struct mm_gk20a *mm)
 static void gk20a_vidmem_clear_mem_worker(struct work_struct *work)
 {
         struct mm_gk20a *mm = container_of(work, struct mm_gk20a,
-                                        vidmem_clear_mem_worker);
+                                        vidmem.clear_mem_worker);
         struct gk20a *g = mm->g;
         struct mem_desc *mem;
 
@@ -3146,6 +3151,7 @@ static void gk20a_vidmem_clear_mem_worker(struct work_struct *work)
                            sg_dma_address(mem->sgt->sgl));
                 gk20a_free_sgtable(&mem->sgt);
 
+                WARN_ON(atomic_dec_return(&mm->vidmem.clears_pending) < 0);
                 mem->size = 0;
                 mem->aperture = APERTURE_INVALID;
 
@@ -5098,7 +5104,7 @@ int gk20a_mm_suspend(struct gk20a *g)
 {
         gk20a_dbg_fn("");
 
-        cancel_work_sync(&g->mm.vidmem_clear_mem_worker);
+        cancel_work_sync(&g->mm.vidmem.clear_mem_worker);
 
         g->ops.mm.cbc_clean(g);
         g->ops.mm.l2_flush(g, false);
diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
index 9002290e..8ce110a1 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
@@ -420,8 +420,10 @@ struct mm_gk20a {
 
                 struct list_head clear_list_head;
                 struct mutex clear_list_mutex;
+
+                struct work_struct clear_mem_worker;
+                atomic_t clears_pending;
         } vidmem;
-        struct work_struct vidmem_clear_mem_worker;
 };
 
 int gk20a_mm_init(struct mm_gk20a *mm);