gpu: nvgpu: Fixes to static offset mappings

This patch addresses two issues in fixes offset mappings:
- VA unmapping did not use lists safely. This caused an application hang
if the application did not free all (fixed offset) buffers before quiting.
- GPU was not powered closing AS node. If the address space had areas that
were not freed, the driver tried to access hw without powering it up first.

Change-Id: Ida526d222ea4e03b8d765eca16574ddc1823e60d
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-on: http://git-master/r/405872
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/as_gk20a.c b/drivers/gpu/nvgpu/gk20a/as_gk20a.c
index 1d604b83..42fa2167 100644
--- a/drivers/gpu/nvgpu/gk20a/as_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/as_gk20a.c
@@ -73,6 +73,7 @@ static int gk20a_as_alloc_share(struct gk20a_as *as,
  */
 int gk20a_as_release_share(struct gk20a_as_share *as_share)
 {
+        struct gk20a *g = as_share->vm->mm->g;
         int err;
 
         gk20a_dbg_fn("");
@@ -80,7 +81,10 @@ int gk20a_as_release_share(struct gk20a_as_share *as_share)
         if (atomic_dec_return(&as_share->ref_cnt) > 0)
                 return 0;
 
+        gk20a_busy(g->dev);
         err = gk20a_vm_release_share(as_share);
+        gk20a_idle(g->dev);
+
         release_as_share_id(as_share->as, as_share->id);
         kfree(as_share);
         return err;
diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index d2174f37..624eec94 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -2350,14 +2350,15 @@ int gk20a_vm_free_space(struct gk20a_as_share *as_share,
         mutex_lock(&vm->update_gmmu_lock);
         va_node = addr_to_reservation(vm, args->offset);
         if (va_node) {
-                struct mapped_buffer_node *buffer;
+                struct mapped_buffer_node *buffer, *n;
 
                 /* there is no need to unallocate the buffers in va. Just
                  * convert them into normal buffers */
 
-                list_for_each_entry(buffer,
-                        &va_node->va_buffers_list, va_buffers_list)
+                list_for_each_entry_safe(buffer, n,
+                        &va_node->va_buffers_list, va_buffers_list) {
                         list_del_init(&buffer->va_buffers_list);
+                }
 
                 list_del(&va_node->reserved_va_list);