[PATCH] drm/i915: add rc6 residency times to debugfs

[Ben Widawsky <ben@bwidawsk.net>]

RC6 residency should be in intervals of 1.28us, and the counter wraps.
Here is an example using awk to get the RC6 and RC6+ residency in
seconds, since boot.

cat /sys/kernel/debug/dri/0/i915_drpc_info  | grep residency | awk -F':' -F' '  '{print $5 * 1.28 / 1000000}'

This is primarily for QA, but has other applications as well.

CC: Arjan van de Ven <arjan@linux.intel.com>
CC: Ouping Zhang <ouping.zhang@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_debugfs.c |    6 ++++++
 drivers/gpu/drm/i915/i915_reg.h     |    3 +++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 66c90d4..cd67d3c 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1133,6 +1133,12 @@ static int gen6_drpc_info(struct seq_file *m)
 
 	seq_printf(m, "Core Power Down: %s\n",
 		   yesno(gt_core_status & GEN6_CORE_CPD_STATE_MASK));
+
+	seq_printf(m, "RC6 residency since boot: %d\n",
+		   I915_READ(GEN6_GT_GFX_RC6));
+
+	seq_printf(m, "RC6+ residency since boot: %d\n",
+		   I915_READ(GEN6_GT_GFX_RC6p));
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 52a06be..5382d8b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3791,6 +3791,9 @@
 						 GEN6_PM_RP_DOWN_THRESHOLD | \
 						 GEN6_PM_RP_DOWN_TIMEOUT)
 
+#define GEN6_GT_GFX_RC6				0x138108
+#define GEN6_GT_GFX_RC6p			0x13810C
+
 #define GEN6_PCODE_MAILBOX			0x138124
 #define   GEN6_PCODE_READY			(1<<31)
 #define   GEN6_READ_OC_PARAMS			0xc
-- 
1.7.9.4