drm/i915: Extend vlv/chv residency resolution

Vlv and chv residency counters are 40 bits in width.
With a control bit, we can choose between upper or lower
32 bit window into this counter.

Lets toggle this bit on and off on and read both parts.
As a result we can push the wrap from 13 seconds to 54
minutes.

v2: commit msg, loop readability, goto elimination (Chris)
v3: bug ref, divide outside runtime pm lock (Chris)

References: https://bugs.freedesktop.org/show_bug.cgi?id=94852
Reported-by: Len Brown <len.brown@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
This commit is contained in:
Mika Kuoppala 2017-03-15 18:07:13 +02:00 committed by Mika Kuoppala
parent c5a0ad114b
commit 47c21d9a1a

View File

@ -8350,12 +8350,51 @@ void intel_pm_setup(struct drm_i915_private *dev_priv)
atomic_set(&dev_priv->pm.wakeref_count, 0); atomic_set(&dev_priv->pm.wakeref_count, 0);
} }
static u64 vlv_residency_raw(struct drm_i915_private *dev_priv,
const i915_reg_t reg)
{
u32 lower, upper, tmp, saved_ctl;
/* The register accessed do not need forcewake. We borrow
* uncore lock to prevent concurrent access to range reg.
*/
spin_lock_irq(&dev_priv->uncore.lock);
saved_ctl = I915_READ_FW(VLV_COUNTER_CONTROL);
if (!(saved_ctl & VLV_COUNT_RANGE_HIGH))
I915_WRITE_FW(VLV_COUNTER_CONTROL,
_MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
/* vlv and chv residency counters are 40 bits in width.
* With a control bit, we can choose between upper or lower
* 32bit window into this counter.
*/
upper = I915_READ_FW(reg);
do {
tmp = upper;
I915_WRITE_FW(VLV_COUNTER_CONTROL,
_MASKED_BIT_DISABLE(VLV_COUNT_RANGE_HIGH));
lower = I915_READ_FW(reg);
I915_WRITE_FW(VLV_COUNTER_CONTROL,
_MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
upper = I915_READ_FW(reg);
} while (upper != tmp);
if (!(saved_ctl & VLV_COUNT_RANGE_HIGH))
I915_WRITE_FW(VLV_COUNTER_CONTROL,
_MASKED_BIT_DISABLE(VLV_COUNT_RANGE_HIGH));
spin_unlock_irq(&dev_priv->uncore.lock);
return lower | (u64)upper << 8;
}
u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv, u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv,
const i915_reg_t reg) const i915_reg_t reg)
{ {
u64 raw_time; /* 32b value may overflow during fixed point math */ u64 time_hw, units, div;
u64 units = 128000ULL, div = 100000ULL;
u64 ret;
if (!intel_enable_rc6()) if (!intel_enable_rc6())
return 0; return 0;
@ -8367,16 +8406,19 @@ u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv,
units = 1000; units = 1000;
div = dev_priv->czclk_freq; div = dev_priv->czclk_freq;
if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH) time_hw = vlv_residency_raw(dev_priv, reg);
units <<= 8;
} else if (IS_GEN9_LP(dev_priv)) { } else if (IS_GEN9_LP(dev_priv)) {
units = 1000; units = 1000;
div = 1200; /* 833.33ns */ div = 1200; /* 833.33ns */
time_hw = I915_READ(reg);
} else {
units = 128000; /* 1.28us */
div = 100000;
time_hw = I915_READ(reg);
} }
raw_time = I915_READ(reg) * units;
ret = DIV_ROUND_UP_ULL(raw_time, div);
intel_runtime_pm_put(dev_priv); intel_runtime_pm_put(dev_priv);
return ret; return DIV_ROUND_UP_ULL(time_hw * units, div);
} }