gpu: nvgpu: split address space for fixed allocs

Allow a special address space node to be split out from the
user adress space or fixed allocations. A debugfs node,

  /d/<gpu>/separate_fixed_allocs

Controls this feature. To enable it:

  # echo <SPLIT_ADDR> > /d/<gpu>/separate_fixed_allocs

Where <SPLIT_ADDR> is the address to do the split on in the
GVA address range. This will cause the split to be made in
all subsequent address space ranges that get created until it
is turned off. To turn this off just echo 0x0 into the same
debugfs node.

Change-Id: I21a3f051c635a90a6bfa8deae53a54db400876f9
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1030303
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index 541e7b50..8a1f82bc 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -591,6 +591,14 @@ struct gk20a {
         int dbg_powergating_disabled_refcount; /*refcount for pg disable */
         int dbg_timeout_disabled_refcount; /*refcount for timeout disable */
 
+        /*
+         * When set subsequent VMAs will separate fixed and non-fixed
+         * allocations. This avoids conflicts with fixed and non-fixed allocs
+         * for some tests. The value in separate_fixed_allocs is used to
+         * determine the split boundary.
+         */
+        u64 separate_fixed_allocs;
+
         void (*remove_support)(struct platform_device *);
 
         u64 pg_ingating_time_us;