gpu: nvgpu: Fix crash on read fail of mc_boot_0_r

This CL handles
- erroneous use of boot_0 function pointer
before being assigned in __nvgpu_check_gpu_state
- And proper handling of error returned from gk20a_readl
in gk20a_mc_boot_0
With these fixes crash is not seen in case mc_boot_0 read
returns 0 in gk20a_mc_boot_0
- And also this handles the recursion caused by mc.boot_0()
calling nvgpu_readl and nvgpu_readl in turn
calling mc.boot_0 in case of read failure

Bug 2010966

Change-Id: Ia087811c67d88948b7fc5fff35e0fabc6ea91989
Signed-off-by: Supriya <ssharatkumar@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1616274
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/io.c b/drivers/gpu/nvgpu/common/linux/io.c
index 729825e7..cde90ddd 100644
--- a/drivers/gpu/nvgpu/common/linux/io.c
+++ b/drivers/gpu/nvgpu/common/linux/io.c
@@ -33,6 +33,16 @@ void nvgpu_writel(struct gk20a *g, u32 r, u32 v)
 
 u32 nvgpu_readl(struct gk20a *g, u32 r)
 {
+        u32 v = __nvgpu_readl(g, r);
+
+        if (v == 0xffffffff)
+                __nvgpu_check_gpu_state(g);
+
+        return v;
+}
+
+u32 __nvgpu_readl(struct gk20a *g, u32 r)
+{
         struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
         u32 v = 0xffffffff;
 
@@ -41,8 +51,6 @@ u32 nvgpu_readl(struct gk20a *g, u32 r)
                 gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x (failed)", r, v);
         } else {
                 v = readl(l->regs + r);
-                if (v == 0xffffffff)
-                        __nvgpu_check_gpu_state(g);
                 gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x", r, v);
         }