gpu: nvgpu: Add barriers for init test

Make sure that all writes have been commited before allowing
the variable storing the init status to be seen as non-zero.
Pair this with a read memory barrier where the check for the
status is done.

Bug 1799159

Change-Id: I938dffdfc2f39187b0dad11b7e283381560961b4
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1211523
(cherry picked from commit 6dd673d24a93c05834c9d96d2022b359ced5b73b)
Reviewed-on: http://git-master/r/1223456
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

2 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a_allocator_bitmap.c b/drivers/gpu/nvgpu/gk20a/gk20a_allocator_bitmap.c
index 29f52081..2291a953 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a_allocator_bitmap.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a_allocator_bitmap.c
@@ -42,6 +42,7 @@ static int gk20a_bitmap_alloc_inited(struct gk20a_allocator *a)
 {
         struct gk20a_bitmap_allocator *ba = a->priv;
 
+        rmb();
         return ba->inited;
 }
 
@@ -405,6 +406,7 @@ int gk20a_bitmap_allocator_init(struct gk20a_allocator *__a,
         if (!a->bitmap)
                 goto fail;
 
+        wmb();
         a->inited = true;
 
         gk20a_init_alloc_debug(__a);
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a_allocator_buddy.c b/drivers/gpu/nvgpu/gk20a/gk20a_allocator_buddy.c
index 70a10c24..ee5e69d2 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a_allocator_buddy.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a_allocator_buddy.c
@@ -1078,6 +1078,7 @@ static int gk20a_buddy_alloc_inited(struct gk20a_allocator *a)
 {
         struct gk20a_buddy_allocator *ba = a->priv;
 
+        rmb();
         return ba->initialized;
 }
 
@@ -1284,6 +1285,7 @@ int __gk20a_buddy_allocator_init(struct gk20a_allocator *__a,
         if (err)
                 goto fail;
 
+        wmb();
         a->initialized = 1;
 
         gk20a_init_alloc_debug(__a);