drm/i915/chv: calculate rc6 residency correctly

The register to read cz count is different from vlv. Also
the counts returned from CCK_CTL1 for BSW are (ticks in 30ns - 1).
czcount_30ns of value 1 is a special case for 320Mhz.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80703
Suggested-by: Deepak S <deepak.s@linux.intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Tested-by: Guo Jinxian <jinxianx.guo@intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 32 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0ebe0f49db28..503da23b6c3f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2281,7 +2281,7 @@ enum punit_power_well {
 /* Same as Haswell, but 72064 bytes now. */
 #define GEN8_CXT_TOTAL_SIZE             (18 * PAGE_SIZE)
 
-
+#define CHV_CLK_CTL1                    0x101100
 #define VLV_CLK_CTL2                    0x101104
 #define   CLK_CTL2_CZCOUNT_30NS_SHIFT   28
 
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index b15c8cee103b..ae7fd8fc27f0 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -47,22 +47,45 @@ static u32 calc_residency(struct drm_device *dev, const u32 reg)
 
         intel_runtime_pm_get(dev_priv);
 
-        /* On VLV, residency time is in CZ units rather than 1.28us */
+        /* On VLV and CHV, residency time is in CZ units rather than 1.28us */
         if (IS_VALLEYVIEW(dev)) {
-                u32 clkctl2;
+                u32 reg, czcount_30ns;
 
-                clkctl2 = I915_READ(VLV_CLK_CTL2) >>
-                        CLK_CTL2_CZCOUNT_30NS_SHIFT;
-                if (!clkctl2) {
-                        WARN(!clkctl2, "bogus CZ count value");
+                if (IS_CHERRYVIEW(dev))
+                        reg = CHV_CLK_CTL1;
+                else
+                        reg = VLV_CLK_CTL2;
+
+                czcount_30ns = I915_READ(reg) >> CLK_CTL2_CZCOUNT_30NS_SHIFT;
+
+                if (!czcount_30ns) {
+                        WARN(!czcount_30ns, "bogus CZ count value");
                         ret = 0;
                         goto out;
                 }
-                units = DIV_ROUND_UP_ULL(30ULL * bias, (u64)clkctl2);
+
+                units = 0;
+                div = 1000000ULL;
+
+                if (IS_CHERRYVIEW(dev)) {
+                        /* Special case for 320Mhz */
+                        if (czcount_30ns == 1) {
+                                div = 10000000ULL;
+                                units = 3125ULL;
+                        } else {
+                                /* chv counts are one less */
+                                czcount_30ns += 1;
+                        }
+                }
+
+                if (units == 0)
+                        units = DIV_ROUND_UP_ULL(30ULL * bias,
+                                                 (u64)czcount_30ns);
+
                 if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH)
                         units <<= 8;
 
-                div = 1000000ULL * bias;
+                div = div * bias;
         }
 
         raw_time = I915_READ(reg) * units;