Slices shutdown is a power savings feature present on Haswell GT3 whereby
parts of HW i.e. slice is shut off on boot or dynamically to save power.
This patch only introduces a way to disable half of Haswell GT3 slices on boot.
v2: Use number of slices on (1 or 2) instead of 0 for half and 1 for full.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.c | 5 +++++
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem.c | 5 +----
drivers/gpu/drm/i915/i915_reg.h | 8 ++++++++
drivers/gpu/drm/i915/intel_drv.h | 1 +
drivers/gpu/drm/i915/intel_pm.c | 20 +++++++++++++++++++-
6 files changed, 35 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a0804fa..71bac6a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -154,6 +154,11 @@ module_param_named(prefault_disable, i915_prefault_disable, bool, 0600);
MODULE_PARM_DESC(prefault_disable,
"Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only.");
+int i915_gt_slices __read_mostly = 2;
+module_param_named(gt_slices, i915_gt_slices, int, 0600);
+MODULE_PARM_DESC(gt_slices,
+ "Haswell GT3 has two slices with many EUs in each of them. Use 2 for better performance or 1 for better power savings. (default:2)");
+
static struct drm_driver driver;
extern int intel_agp_enabled;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b12d942..27073e8 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1836,6 +1836,7 @@ extern bool i915_fastboot __read_mostly;
extern int i915_enable_pc8 __read_mostly;
extern int i915_pc8_timeout __read_mostly;
extern bool i915_prefault_disable __read_mostly;
+extern int i915_gt_slices __read_mostly;
extern int i915_suspend(struct drm_device *dev, pm_message_t state);
extern int i915_resume(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e7b39d7..f9c32d1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4439,10 +4439,7 @@ i915_gem_init_hw(struct drm_device *dev)
if (dev_priv->ellc_size)
I915_WRITE(HSW_IDICR, I915_READ(HSW_IDICR) | IDIHASHMSK(0xf));
- if (IS_HSW_GT3(dev))
- I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_ENABLED);
- else
- I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_DISABLED);
+ intel_init_gt_slices(dev);
if (HAS_PCH_NOP(dev)) {
u32 temp = I915_READ(GEN7_MSG_CTL);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 3f303ba..a2e7deb 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -270,6 +270,14 @@
#define LOWER_SLICE_ENABLED (1<<0)
#define LOWER_SLICE_DISABLED (0<<0)
+#define HSW_GT_SLICE_INFO 0x138064
+#define SLICE_SEL_BOTH (1<<3)
+#define SLICE_AUTOWAKE (1<<2)
+#define SLICE_STATUS_MASK 0x3
+#define SLICE_STATUS_GT_OFF (0<<0)
+#define SLICE_STATUS_MAIN_ON (2<<0)
+#define SLICE_STATUS_BOTH_ON (3<<0)
+
/*
* 3D instructions used by the kernel
*/
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 9d2624f..42c3983 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -836,6 +836,7 @@ void intel_set_power_well(struct drm_device *dev, bool enable);
void intel_enable_gt_powersave(struct drm_device *dev);
void intel_disable_gt_powersave(struct drm_device *dev);
void ironlake_teardown_rc6(struct drm_device *dev);
+void intel_init_gt_slices(struct drm_device *dev);
void gen6_update_ring_freq(struct drm_device *dev);
void gen6_rps_idle(struct drm_i915_private *dev_priv);
void gen6_rps_boost(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 09ac9e7..02d1b1f 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3869,6 +3869,25 @@ static void gen6_enable_rps(struct drm_device *dev)
gen6_gt_force_wake_put(dev_priv);
}
+void intel_init_gt_slices(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ if (!IS_HSW_GT3(dev))
+ return;
+
+ I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_ENABLED);
+
+ if (i915_gt_slices == 1) {
+ I915_WRITE(HSW_GT_SLICE_INFO, ~SLICE_SEL_BOTH);
+ I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_DISABLED);
+ return;
+ }
+
+ if (i915_gt_slices != 2)
+ DRM_ERROR("Invalid number of slices. 2 GT slices enabled\n");
+}
+
void gen6_update_ring_freq(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -5995,4 +6014,3 @@ void intel_pm_init(struct drm_device *dev)
INIT_DELAYED_WORK(&dev_priv->rps.delayed_resume_work,
intel_gen6_powersave_work);
}
-
--
1.7.11.7
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