gpu: nvgpu: Remove GPU MMIO access on power/rail gate

This is to weed out accesses to the GPU while it is gated. Otherwise
the accesses are silently dropped or cause a HW hang (on older chips).

Bug 1514949

Change-Id: Ice4cdb9f1f736978ebb3db847f39c7439bf98134
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/416339
Reviewed-by: Mitch Luban <mluban@nvidia.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index 991891c5..3871eb17 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -232,9 +232,11 @@ struct gk20a {
 
         struct resource *reg_mem;
         void __iomem *regs;
+        void __iomem *regs_saved;
 
         struct resource *bar1_mem;
         void __iomem *bar1;
+        void __iomem *bar1_saved;
 
         bool power_on;
 
@@ -487,6 +489,9 @@ static inline void gk20a_mem_wr32(void *ptr, int w, u32 data)
 }
 
 /* register accessors */
+int gk20a_lockout_registers(struct gk20a *g);
+int gk20a_restore_registers(struct gk20a *g);
+
 static inline void gk20a_writel(struct gk20a *g, u32 r, u32 v)
 {
         gk20a_dbg(gpu_dbg_reg, " r=0x%x v=0x%x", r, v);