1 files changed, 18 insertions, 14 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
index 57283343..49a1c1a8 100644
--- a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
@@ -1,7 +1,7 @@
 /*
  * Color decompression engine support
  *
- * Copyright (c) 2014, NVIDIA Corporation.  All rights reserved.
+ * Copyright (c) 2014-2015, NVIDIA Corporation.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -979,17 +979,23 @@ __releases(&cde_app->mutex)
                 map_size = compbits_buf->size - map_offset;
         }
 
-        /* map the destination buffer */
-        get_dma_buf(compbits_buf); /* a ref for gk20a_vm_map */
-        map_vaddr = gk20a_vm_map(cde_ctx->vm, compbits_buf, 0,
-                                 NVGPU_MAP_BUFFER_FLAGS_CACHEABLE_TRUE,
-                                 compbits_kind, NULL, true,
-                                 gk20a_mem_flag_none,
-                                 map_offset, map_size);
+        /* map the destination buffer, if not cached yet */
+        /* races protected by the cde app mutex above */
+        map_vaddr = gk20a_vm_cde_mapped(cde_ctx->vm, compbits_buf);
         if (!map_vaddr) {
-                dma_buf_put(compbits_buf);
-                err = -EINVAL;
-                goto exit_unlock;
+                /* take a ref for gk20a_vm_map, pair is in (cached) unmap */
+                get_dma_buf(compbits_buf);
+                map_vaddr = gk20a_vm_map(cde_ctx->vm, compbits_buf, 0,
+                                NVGPU_MAP_BUFFER_FLAGS_CACHEABLE_TRUE,
+                                compbits_kind, NULL, true,
+                                gk20a_mem_flag_none,
+                                map_offset, map_size);
+                if (!map_vaddr) {
+                        dma_buf_put(compbits_buf);
+                        err = -EINVAL;
+                        goto exit_unlock;
+                }
+                gk20a_vm_mark_cde_mapped(cde_ctx->vm, compbits_buf, map_vaddr);
         }
 
         /* store source buffer compression tags */
@@ -1052,9 +1058,7 @@ __releases(&cde_app->mutex)
 
 exit_unlock:
 
-        /* unmap the buffers - channel holds references to them now */
-        if (map_vaddr)
-                gk20a_vm_unmap(cde_ctx->vm, map_vaddr);
+        /* leave map_vaddr mapped - released when unmapped from userspace */
 
         mutex_unlock(&g->cde_app.mutex);
         return err;