gpu: nvgpu: Provide cpu gpu time correlation via ioctl

bug 1648908

Provides pairs of CPU and GPU timestamps that
can be used for correlatiing the two timebases

- IOCTL made available /dev/nvhost-ctrl-gpu

Change-Id: I1458b9d33d794b1b02ec9fd29ed9426756b94bcd
Signed-off-by: Arul Sekar <aruls@nvidia.com>
Reviewed-on: http://git-master/r/1029732
Reviewed-by: Arun Gona <agona@nvidia.com>
Tested-by: Arun Gona <agona@nvidia.com>
Reviewed-on: http://git-master/r/1111715
GVS: Gerrit_Virtual_Submit
Reviewed-by: Thomas Fleury <tfleury@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 27 insertions, 3 deletions

diff --git a/include/uapi/linux/nvgpu.h b/include/uapi/linux/nvgpu.h
index 0787d4e4..68c1c4e0 100644
--- a/include/uapi/linux/nvgpu.h
+++ b/include/uapi/linux/nvgpu.h
@@ -351,6 +351,28 @@ struct nvgpu_gpu_get_buffer_info_args {
         };
 };
 
+#define NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_MAX_COUNT               16
+#define NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_TSC              1
+#define NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_JIFFIES          2
+#define NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_TIMEOFDAY        3
+
+struct nvgpu_gpu_get_cpu_time_correlation_sample {
+        /* gpu timestamp value */
+        __u64 cpu_timestamp;
+        /* raw GPU counter (PTIMER) value */
+        __u64 gpu_timestamp;
+};
+
+struct nvgpu_gpu_get_cpu_time_correlation_info_args {
+        /* timestamp pairs */
+        struct nvgpu_gpu_get_cpu_time_correlation_sample samples[
+                NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_MAX_COUNT];
+        /* number of pairs to read */
+        __u32 count;
+        /* cpu clock source id */
+        __u32 source_id;
+};
+
 #define NVGPU_GPU_IOCTL_ZCULL_GET_CTX_SIZE \
         _IOR(NVGPU_GPU_IOCTL_MAGIC, 1, struct nvgpu_gpu_zcull_get_ctx_size_args)
 #define NVGPU_GPU_IOCTL_ZCULL_GET_INFO \
@@ -397,11 +419,13 @@ struct nvgpu_gpu_get_buffer_info_args {
         _IO(NVGPU_GPU_IOCTL_MAGIC, 22)
 #define NVGPU_GPU_IOCTL_CLEAR_SM_ERRORS \
         _IO(NVGPU_GPU_IOCTL_MAGIC, 23)
-
+#define NVGPU_GPU_IOCTL_GET_CPU_TIME_CORRELATION_INFO \
+        _IOWR(NVGPU_GPU_IOCTL_MAGIC, 24, \
+                        struct nvgpu_gpu_get_cpu_time_correlation_info_args)
 #define NVGPU_GPU_IOCTL_LAST            \
-        _IOC_NR(NVGPU_GPU_IOCTL_CLEAR_SM_ERRORS)
+        _IOC_NR(NVGPU_GPU_IOCTL_GET_CPU_TIME_CORRELATION_INFO)
 #define NVGPU_GPU_IOCTL_MAX_ARG_SIZE    \
-        sizeof(struct nvgpu_gpu_prepare_compressible_read_args)
+        sizeof(struct nvgpu_gpu_get_cpu_time_correlation_info_args)
 
 /*
  * /dev/nvhost-tsg-gpu device