drm/msm: Add param for userspace to query suspend count

Performance counts, and ALWAYS_ON counters used for capturing GPU
timestamps, lose their state across suspend/resume cycles.  Userspace
tooling for performance monitoring needs to be aware of this.  For
example, after a suspend userspace needs to recalibrate it's offset
between CPU and GPU time.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Jordan Crouse <jordan@cosmicpenguin.net>
Link: https://lore.kernel.org/r/20210325012358.1759770-3-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

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

@@ -273,6 +273,9 @@ int adreno_get_param(struct msm_gpu *gpu, uint32_t param, uint64_t *value)
 	case MSM_PARAM_FAULTS:
 		*value = gpu->global_faults;
 		return 0;
+	case MSM_PARAM_SUSPENDS:
+		*value = gpu->suspend_count;
+		return 0;
 	default:
 		DBG("%s: invalid param: %u", gpu->name, param);
 		return -EINVAL;

drivers/gpu/drm/msm/msm_drv.c

@@ -39,6 +39,7 @@
  *           GEM object's debug name
  * - 1.5.0 - Add SUBMITQUERY_QUERY ioctl
  * - 1.6.0 - Syncobj support
+ * - 1.7.0 - Add MSM_PARAM_SUSPENDS to access suspend count
  */
 #define MSM_VERSION_MAJOR	1
 #define MSM_VERSION_MINOR	6

drivers/gpu/drm/msm/msm_gpu.c

@@ -251,6 +251,8 @@ int msm_gpu_pm_suspend(struct msm_gpu *gpu)
 	if (ret)
 		return ret;
 
+	gpu->suspend_count++;
+
 	return 0;
 }
 

drivers/gpu/drm/msm/msm_gpu.h

@@ -152,6 +152,8 @@ struct msm_gpu {
 		ktime_t time;
 	} devfreq;
 
+	uint32_t suspend_count;
+
 	struct msm_gpu_state *crashstate;
 	/* True if the hardware supports expanded apriv (a650 and newer) */
 	bool hw_apriv;

include/uapi/drm/msm_drm.h

@@ -76,6 +76,7 @@ struct drm_msm_timespec {
 #define MSM_PARAM_NR_RINGS   0x07
 #define MSM_PARAM_PP_PGTABLE 0x08  /* => 1 for per-process pagetables, else 0 */
 #define MSM_PARAM_FAULTS     0x09
+#define MSM_PARAM_SUSPENDS   0x0a
 
 struct drm_msm_param {
 	__u32 pipe;           /* in, MSM_PIPE_x */