[PATCH v5] drm/i915/vlv: WA for Turbo and RC6 to work together.

deepak.s
2014-03-27T06:35:08Z

From: Deepak S <deepak.s@linux.intel.com>

With RC6 enabled, BYT has an HW issue in determining the right
Gfx busyness.
WA for Turbo + RC6: Use SW based Gfx busy-ness detection to decide
on increasing/decreasing the freq. This logic will monitor C0
counters of render/media power-wells over EI period and takes
necessary action based on these values

v2: Refactor duplicate code. (Ville)

v3: Reformat the comments. (Ville)

v4: Enable required counters and remove unwanted code (Ville)

v5: Resolved comments and remove kernel-doc style comments. (Ville)

Signed-off-by: Deepak S <deepak.s@linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 15 +++++
drivers/gpu/drm/i915/i915_irq.c | 135 +++++++++++++++++++++++++++++++++++++++-
drivers/gpu/drm/i915/i915_reg.h | 12 +++-
drivers/gpu/drm/i915/intel_pm.c | 13 +++-
4 files changed, 170 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 7c212f3..c48ea93 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -816,6 +816,12 @@ struct i915_suspend_saved_registers {
u32 savePCH_PORT_HOTPLUG;
};

+struct intel_rps_ei_calc {
+ u32 cz_ts_ei;
+ u32 render_ei_c0;
+ u32 media_ei_c0;
+};
+
struct intel_gen6_power_mgmt {
/* work and pm_iir are protected by dev_priv->irq_lock */
struct work_struct work;
@@ -843,6 +849,8 @@ struct intel_gen6_power_mgmt {
bool rp_up_masked;
bool rp_down_masked;

+ u32 ei_interrupt_count;
+
int last_adj;
enum { LOW_POWER, BETWEEN, HIGH_POWER } power;

@@ -1403,6 +1411,13 @@ typedef struct drm_i915_private {
/* gen6+ rps state */
struct intel_gen6_power_mgmt rps;

+ /* rps wa up ei calculation */
+ struct intel_rps_ei_calc rps_up_ei;
+
+ /* rps wa down ei calculation */
+ struct intel_rps_ei_calc rps_down_ei;
+
+
/* ilk-only ips/rps state. Everything in here is protected by the global
* mchdev_lock in intel_pm.c */
struct intel_ilk_power_mgmt ips;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 300f127..4b421b4 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1121,6 +1121,132 @@ void gen6_set_pm_mask(struct drm_i915_private *dev_priv,
}
}

+static u32 vlv_c0_residency(struct drm_i915_private *dev_priv,
+ struct intel_rps_ei_calc *rps_ei)
+{
+ u32 cz_ts, cz_freq_khz;
+ u32 render_count, media_count;
+ u32 elapsed_render, elapsed_media, elapsed_time;
+ u32 residency = 0;
+
+ cz_ts = vlv_punit_read(dev_priv, PUNIT_REG_CZ_TIMESTAMP);
+ cz_freq_khz = DIV_ROUND_CLOSEST(dev_priv->mem_freq * 1000, 4);
+
+ render_count = I915_READ(VLV_RENDER_C0_COUNT_REG);
+ media_count = I915_READ(VLV_MEDIA_C0_COUNT_REG);
+
+ if (rps_ei->cz_ts_ei == 0) {
+ rps_ei->cz_ts_ei = cz_ts;
+ rps_ei->render_ei_c0 = render_count;
+ rps_ei->media_ei_c0 = media_count;
+
+ return dev_priv->rps.cur_freq;
+ }
+
+ elapsed_time = cz_ts - rps_ei->cz_ts_ei;
+ rps_ei->cz_ts_ei = cz_ts;
+
+ elapsed_render = render_count - rps_ei->render_ei_c0;
+ rps_ei->render_ei_c0 = render_count;
+
+ elapsed_media = media_count - rps_ei->media_ei_c0;
+ rps_ei->media_ei_c0 = media_count;
+
+ /* Convert all the counters into common unit of milli sec */
+ elapsed_time /= VLV_CZ_CLOCK_TO_MILLI_SEC;
+ elapsed_render /= cz_freq_khz;
+ elapsed_media /= cz_freq_khz;
+
+ /*
+ * Calculate overall C0 residency percentage
+ * only if elapsed time is non zero
+ */
+ if (elapsed_time) {
+ residency =
+ ((max(elapsed_render, elapsed_media) * 100)
+ / elapsed_time);
+ }
+
+ return residency;
+}
+
+
+/**
+ * vlv_calc_delay_from_C0_counters - Increase/Decrease freq based on GPU
+ * busy-ness calculated from C0 counters of render & media power wells
+ * @dev_priv: DRM device private
+ *
+ */
+static u32 vlv_calc_delay_from_C0_counters(struct drm_i915_private *dev_priv)
+{
+ u32 residency_C0_up = 0, residency_C0_down = 0;
+ u8 new_delay, adj;
+
+ dev_priv->rps.ei_interrupt_count++;
+
+ WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
+
+
+ if (dev_priv->rps_up_ei.cz_ts_ei == 0) {
+ vlv_c0_residency(dev_priv, &dev_priv->rps_up_ei);
+ vlv_c0_residency(dev_priv, &dev_priv->rps_down_ei);
+ return dev_priv->rps.cur_freq;
+ }
+
+
+ /*
+ * To down throttle, C0 residency should be less than down threshold
+ * for continous EI intervals. So calculate down EI counters
+ * once in VLV_INT_COUNT_FOR_DOWN_EI
+ */
+ if (dev_priv->rps.ei_interrupt_count == VLV_INT_COUNT_FOR_DOWN_EI) {
+
+ dev_priv->rps.ei_interrupt_count = 0;
+
+ residency_C0_down = vlv_c0_residency(dev_priv,
+ &dev_priv->rps_down_ei);
+ } else {
+ residency_C0_up = vlv_c0_residency(dev_priv,
+ &dev_priv->rps_up_ei);
+ }
+
+ new_delay = dev_priv->rps.cur_freq;
+
+ adj = dev_priv->rps.last_adj;
+ /* C0 residency is greater than UP threshold. Increase Frequency */
+ if (residency_C0_up >= VLV_RP_UP_EI_THRESHOLD) {
+ if (adj > 0)
+ adj *= 2;
+ else
+ adj = 1;
+
+ if (dev_priv->rps.cur_freq < dev_priv->rps.max_freq_softlimit)
+ new_delay = dev_priv->rps.cur_freq + adj;
+
+ /*
+ * For better performance, jump directly
+ * to RPe if we're below it.
+ */
+ if (new_delay < dev_priv->rps.efficient_freq)
+ new_delay = dev_priv->rps.efficient_freq;
+
+ } else if (!dev_priv->rps.ei_interrupt_count &&
+ (residency_C0_down < VLV_RP_DOWN_EI_THRESHOLD)) {
+ if (adj < 0)
+ adj *= 2;
+ else
+ adj = -1;
+ /*
+ * This means, C0 residency is less than down threshold over
+ * a period of VLV_INT_COUNT_FOR_DOWN_EI. So, reduce the freq
+ */
+ if (dev_priv->rps.cur_freq > dev_priv->rps.max_freq_softlimit)
+ new_delay = dev_priv->rps.cur_freq + adj;
+ }
+
+ return new_delay;
+}
+
static void gen6_pm_rps_work(struct work_struct *work)
{
drm_i915_private_t *dev_priv = container_of(work, drm_i915_private_t,
@@ -1163,6 +1289,8 @@ static void gen6_pm_rps_work(struct work_struct *work)
else
new_delay = dev_priv->rps.min_freq_softlimit;
adj = 0;
+ } else if (pm_iir & GEN6_PM_RP_UP_EI_EXPIRED) {
+ new_delay = vlv_calc_delay_from_C0_counters(dev_priv);
} else if (pm_iir & GEN6_PM_RP_DOWN_THRESHOLD) {
if (adj < 0)
adj *= 2;
@@ -3053,6 +3181,7 @@ static void gen5_gt_irq_postinstall(struct drm_device *dev)
pm_irqs |= PM_VEBOX_USER_INTERRUPT;

dev_priv->pm_irq_mask = 0xffffffff;
+
I915_WRITE(GEN6_PMIIR, I915_READ(GEN6_PMIIR));
I915_WRITE(GEN6_PMIMR, dev_priv->pm_irq_mask);
I915_WRITE(GEN6_PMIER, pm_irqs);
@@ -4095,7 +4224,11 @@ void intel_irq_init(struct drm_device *dev)
INIT_WORK(&dev_priv->l3_parity.error_work, ivybridge_parity_work);

/* Let's track the enabled rps events */
- dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;
+ if (IS_VALLEYVIEW(dev))
+ /* WAUseRC0ResidenncyTurbo:VLV */
+ dev_priv->pm_rps_events = GEN6_PM_RP_UP_EI_EXPIRED;
+ else
+ dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;

setup_timer(&dev_priv->gpu_error.hangcheck_timer,
i915_hangcheck_elapsed,
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 927a7c1..e334bf1 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -506,6 +506,7 @@ enum punit_power_well {
#define PUNIT_REG_GPU_FREQ_STS 0xd8
#define GENFREQSTATUS (1<<0)
#define PUNIT_REG_MEDIA_TURBO_FREQ_REQ 0xdc
+#define PUNIT_REG_CZ_TIMESTAMP 0xce

#define PUNIT_FUSE_BUS2 0xf6 /* bits 47:40 */
#define PUNIT_FUSE_BUS1 0xf5 /* bits 55:48 */
@@ -521,6 +522,11 @@ enum punit_power_well {
#define FB_FMAX_VMIN_FREQ_LO_SHIFT 27
#define FB_FMAX_VMIN_FREQ_LO_MASK 0xf8000000

+#define VLV_CZ_CLOCK_TO_MILLI_SEC 100000
+#define VLV_RP_UP_EI_THRESHOLD 90
+#define VLV_RP_DOWN_EI_THRESHOLD 70
+#define VLV_INT_COUNT_FOR_DOWN_EI 5
+
/* vlv2 north clock has */
#define CCK_FUSE_REG 0x8
#define CCK_FUSE_HPLL_FREQ_MASK 0x3
@@ -4984,6 +4990,7 @@ enum punit_power_well {
#define VLV_GTLC_PW_STATUS 0x130094
#define VLV_GTLC_PW_RENDER_STATUS_MASK 0x80
#define VLV_GTLC_PW_MEDIA_STATUS_MASK 0x20
+#define VLV_GTLC_SURVIVABILITY_REG 0x130098
#define FORCEWAKE_MT 0xa188 /* multi-threaded */
#define FORCEWAKE_KERNEL 0x1
#define FORCEWAKE_USER 0x2
@@ -5112,12 +5119,15 @@ enum punit_power_well {
#define GEN6_GT_GFX_RC6_LOCKED 0x138104
#define VLV_COUNTER_CONTROL 0x138104
#define VLV_COUNT_RANGE_HIGH (1<<15)
+#define VLV_MEDIA_RC0_COUNT_EN (1<<5)
+#define VLV_RENDER_RC0_COUNT_EN (1<<4)
#define VLV_MEDIA_RC6_COUNT_EN (1<<1)
#define VLV_RENDER_RC6_COUNT_EN (1<<0)
#define GEN6_GT_GFX_RC6 0x138108
#define GEN6_GT_GFX_RC6p 0x13810C
#define GEN6_GT_GFX_RC6pp 0x138110
-
+#define VLV_RENDER_C0_COUNT_REG 0x138118
+#define VLV_MEDIA_C0_COUNT_REG 0x13811C
#define GEN6_PCODE_MAILBOX 0x138124
#define GEN6_PCODE_READY (1<<31)
#define GEN6_READ_OC_PARAMS 0xc
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index b66a43b..30730be 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3097,9 +3097,13 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
~VLV_GFX_CLK_FORCE_ON_BIT);

/* Unmask Up interrupts */
- dev_priv->rps.rp_up_masked = true;
- gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
+ if (dev_priv->pm_rps_events & GEN6_PM_RP_UP_EI_EXPIRED)
+ I915_WRITE(GEN6_PMINTRMSK, ~dev_priv->pm_rps_events);
+ else {
+ dev_priv->rps.rp_up_masked = true;
+ gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
dev_priv->rps.min_freq_softlimit);
+ }
}

void gen6_rps_idle(struct drm_i915_private *dev_priv)
@@ -3619,6 +3623,7 @@ static void valleyview_enable_rps(struct drm_device *dev)
I915_WRITE(GEN6_RP_DOWN_EI, 350000);

I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
+ I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 0xf4240);

I915_WRITE(GEN6_RP_CONTROL,
GEN6_RP_MEDIA_TURBO |
@@ -3639,9 +3644,11 @@ static void valleyview_enable_rps(struct drm_device *dev)

/* allows RC6 residency counter to work */
I915_WRITE(VLV_COUNTER_CONTROL,
- _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
+ _MASKED_BIT_ENABLE(VLV_MEDIA_RC0_COUNT_EN |
+ VLV_RENDER_RC0_COUNT_EN |
VLV_MEDIA_RC6_COUNT_EN |
VLV_RENDER_RC6_COUNT_EN));
+
if (intel_enable_rc6(dev) & INTEL_RC6_ENABLE)
rc6_mode = GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;

--
1.9.1