[PATCH 1/2] 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 various RC6 and RC6+ residency
times 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. An
upcoming patch to add interfaces should be more interesting to
application developers.

v2: move comment to the correct place

v3: display with %u instead of %d, for Ouping

CC: Ouping Zhang <ouping.zhang@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c |   11 +++++++++++
 drivers/gpu/drm/i915/i915_reg.h     |    5 +++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 66c90d4..0b9c1e8 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1133,6 +1133,17 @@ 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));
+
+	/* Not exactly sure what this is */
+	seq_printf(m, "RC6 \"Locked to RPn\" residency since boot: %u\n",
+		   I915_READ(GEN6_GT_GFX_RC6_LOCKED));
+	seq_printf(m, "RC6 residency since boot: %u\n",
+		   I915_READ(GEN6_GT_GFX_RC6));
+	seq_printf(m, "RC6+ residency since boot: %u\n",
+		   I915_READ(GEN6_GT_GFX_RC6p));
+	seq_printf(m, "RC6++ residency since boot: %u\n",
+		   I915_READ(GEN6_GT_GFX_RC6pp));
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f3609f2..b1c3d35 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3799,6 +3799,11 @@
 						 GEN6_PM_RP_DOWN_THRESHOLD | \
 						 GEN6_PM_RP_DOWN_TIMEOUT)
 
+#define GEN6_GT_GFX_RC6_LOCKED			0x138104
+#define GEN6_GT_GFX_RC6				0x138108
+#define GEN6_GT_GFX_RC6p			0x13810C
+#define GEN6_GT_GFX_RC6pp			0x138110
+
 #define GEN6_PCODE_MAILBOX			0x138124
 #define   GEN6_PCODE_READY			(1<<31)
 #define   GEN6_READ_OC_PARAMS			0xc
-- 
1.7.9.4