gpu: nvgpu: Enabling/disabling FECS trace support

- To enable FECS trace support, nvgpu should set the MSB
of the read pointer (MAILBOX1).
- The ucode will check if the feature is enabled/disabled
before writing a record into the circular buffer. If the
feature is disabled, it will not write the record.
- If the feature is enabled and the buffer is not allocated,
HW will throw a page fault error.

Bug 2459186
Bug 200542611

Change-Id: I6f181643737d1cf1bda02077eaa714a3f4ef3d8c
Signed-off-by: seshendra <sgadagottu@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2189250
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/ctxsw_trace.h b/drivers/gpu/nvgpu/include/nvgpu/ctxsw_trace.h
index 2da6b837..033e020a 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/ctxsw_trace.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/ctxsw_trace.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2017-2019, NVIDIA CORPORATION.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -48,6 +48,7 @@ struct channel_gk20a;
         ((p)->tag_bits[(n) / 64] &   (1 << ((n) & 63)))
 
 #define NVGPU_GPU_CTXSW_FILTER_SIZE (NVGPU_GPU_CTXSW_TAG_LAST + 1)
+#define NVGPU_FECS_TRACE_FEATURE_CONTROL_BIT 31
 
 struct nvgpu_gpu_ctxsw_trace_filter {
         u64 tag_bits[(NVGPU_GPU_CTXSW_FILTER_SIZE + 63) / 64];
diff --git a/drivers/gpu/nvgpu/include/nvgpu/enabled.h b/drivers/gpu/nvgpu/include/nvgpu/enabled.h
index 79bffcac..76f0f2bd 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/enabled.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/enabled.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2017-2019, NVIDIA CORPORATION.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -37,6 +37,7 @@ struct gk20a;
 #define NVGPU_FECS_TRACE_VA                     4
 #define NVGPU_CAN_RAILGATE                      5
 #define NVGPU_KERNEL_IS_DYING                   6
+#define NVGPU_FECS_TRACE_FEATURE_CONTROL        7
 
 /*
  * ECC flags