drm/msm: add max-freq gpu param to uapi

We need this in userspace for interpreting some of the perf ctrs.

Note possibly not quite sufficient if we had some frequency mgmt
approach other than race-to-idle.  Not really sure what the best
thing to do if we did.  Although displaying results as a percentage
of max frequence seems sensible(ish) if we did.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/msm/adreno/adreno_gpu.c

@@ -41,6 +41,9 @@ int adreno_get_param(struct msm_gpu *gpu, uint32_t param, uint64_t *value)
 				(adreno_gpu->rev.major << 16) |
 				(adreno_gpu->rev.core << 24);
 		return 0;
+	case MSM_PARAM_MAX_FREQ:
+		*value = adreno_gpu->base.fast_rate;
+		return 0;
 	default:
 		DBG("%s: invalid param: %u", gpu->name, param);
 		return -EINVAL;

include/uapi/drm/msm_drm.h

@@ -50,6 +50,7 @@ struct drm_msm_timespec {
 #define MSM_PARAM_GPU_ID     0x01
 #define MSM_PARAM_GMEM_SIZE  0x02
 #define MSM_PARAM_CHIP_ID    0x03
+#define MSM_PARAM_MAX_FREQ   0x04
 
 struct drm_msm_param {
 	__u32 pipe;           /* in, MSM_PIPE_x */