[Intel-gfx] [PATCH v5 1/1] drm/i915/bxt: Check BIOS RC6 setup before enabling RC6

Sagar Arun Kamble sagar.a.kamble at intel.com
Thu Jan 14 07:56:11 PST 2016


RC6 setup is shared between BIOS and Driver. BIOS sets up subset of RC6
setup registers. If those are not setup Driver should not enable RC6.
For implementing this, driver can check RC_CTRL0 and RC_CTRL1 values
to know if BIOS has enabled HW/SW RC6.
This will also enable user to control RC6 using BIOS settings alone.
RC6 related instability can be avoided by disabling via BIOS settings
till driver fixes it.

v2: Had placed logic in gen8 function by mistake. Fixed it.
Ensuring RPM is not enabled in case BIOS disabled RC6.

v3: Need to disable RPM if RC6 is disabled due to BIOS settings. (Daniel)
Runtime PM enabling happens before gen9_enable_rc6.
Moved the updation of enable_rc6 parameter in intel_uncore_sanitize.

v4: Added elaborate check for BIOS RC6 setup. Prepared check_pctx for bxt. (Imre)

v5: Caching reserved stolen base and size in the driver private data.
Reorganized RC6 setup check. Moved from gen9_enable_rc6 to intel_uncore_sanitize. (Imre)

Cc: Imre Deak <imre.deak at intel.com>
Change-Id: If89518708e133be6b3c7c6f90869fb66224b7b87
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h        |  1 +
 drivers/gpu/drm/i915/i915_gem_gtt.h    |  2 ++
 drivers/gpu/drm/i915/i915_gem_stolen.c | 39 ++++++++++++++++++----
 drivers/gpu/drm/i915/i915_reg.h        | 11 +++++++
 drivers/gpu/drm/i915/intel_drv.h       |  1 +
 drivers/gpu/drm/i915/intel_pm.c        | 59 ++++++++++++++++++++++++++++++++--
 drivers/gpu/drm/i915/intel_uncore.c    |  4 +++
 7 files changed, 109 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index cf7e0fc..0c8e61c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3223,6 +3223,7 @@ int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *dev_priv,
 					 u64 end);
 void i915_gem_stolen_remove_node(struct drm_i915_private *dev_priv,
 				 struct drm_mm_node *node);
+int i915_gem_init_stolen_reserved(struct drm_device *dev);
 int i915_gem_init_stolen(struct drm_device *dev);
 void i915_gem_cleanup_stolen(struct drm_device *dev);
 struct drm_i915_gem_object *
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index b448ad8..20ff6ca 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -343,6 +343,8 @@ struct i915_gtt {
 
 	size_t stolen_size;		/* Total size of stolen memory */
 	size_t stolen_usable_size;	/* Total size minus BIOS reserved */
+	size_t stolen_reserved_base;
+	size_t stolen_reserved_size;
 	u64 mappable_end;		/* End offset that we can CPU map */
 	struct io_mapping *mappable;	/* Mapping to our CPU mappable region */
 	phys_addr_t mappable_base;	/* PA of our GMADR */
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 3476877..d5a65d9 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -386,14 +386,12 @@ static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv,
 		*size = stolen_top - *base;
 }
 
-int i915_gem_init_stolen(struct drm_device *dev)
+int i915_gem_init_stolen_reserved(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	unsigned long reserved_total, reserved_base = 0, reserved_size;
+	unsigned long reserved_base = 0, reserved_size;
 	unsigned long stolen_top;
 
-	mutex_init(&dev_priv->mm.stolen_lock);
-
 #ifdef CONFIG_INTEL_IOMMU
 	if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
 		DRM_INFO("DMAR active, disabling use of stolen memory\n");
@@ -458,9 +456,38 @@ int i915_gem_init_stolen(struct drm_device *dev)
 		return 0;
 	}
 
+	dev_priv->gtt.stolen_reserved_base = reserved_base;
+	dev_priv->gtt.stolen_reserved_size = reserved_size;
+
+	return 0;
+}
+
+int i915_gem_init_stolen(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned long reserved_total;
+	unsigned long stolen_top;
+
+	mutex_init(&dev_priv->mm.stolen_lock);
+
+#ifdef CONFIG_INTEL_IOMMU
+	if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
+		DRM_INFO("DMAR active, disabling use of stolen memory\n");
+		return 0;
+	}
+#endif
+
+	if (dev_priv->gtt.stolen_size == 0)
+		return 0;
+
+	if (dev_priv->mm.stolen_base == 0)
+		return 0;
+
+	stolen_top = dev_priv->mm.stolen_base + dev_priv->gtt.stolen_size;
+
 	/* It is possible for the reserved area to end before the end of stolen
-	 * memory, so just consider the start. */
-	reserved_total = stolen_top - reserved_base;
+	* memory, so just consider the start. */
+	reserved_total = stolen_top - dev_priv->gtt.stolen_reserved_base;
 
 	DRM_DEBUG_KMS("Memory reserved for graphics device: %zuK, usable: %luK\n",
 		      dev_priv->gtt.stolen_size >> 10,
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 007ae83..19ddf79 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6765,6 +6765,16 @@ enum skl_disp_power_wells {
 
 #define  VLV_PMWGICZ				_MMIO(0x1300a4)
 
+#define  RC6_LOCATION				_MMIO(0xD40)
+#define  RC6_CTX_IN_DRAM			1
+#define  RC6_CTX_BASE				_MMIO(0xD48)
+#define  RC6_CTX_BASE_MASK			0xFFFFFFF0
+#define  PWRCTX_MAXCNT_RCSUNIT			_MMIO(0x2054)
+#define  PWRCTX_MAXCNT_VCSUNIT0			_MMIO(0x12054)
+#define  PWRCTX_MAXCNT_BCSUNIT			_MMIO(0x22054)
+#define  PWRCTX_MAXCNT_VECSUNIT			_MMIO(0x1A054)
+#define  PWRCTX_MAXCNT_VCSUNIT1			_MMIO(0x1C054)
+#define  IDLE_TIME_MASK				0xFFFFF
 #define  FORCEWAKE				_MMIO(0xA18C)
 #define  FORCEWAKE_VLV				_MMIO(0x1300b0)
 #define  FORCEWAKE_ACK_VLV			_MMIO(0x1300b4)
@@ -6903,6 +6913,7 @@ enum skl_disp_power_wells {
 #define GEN6_RPDEUC				_MMIO(0xA084)
 #define GEN6_RPDEUCSW				_MMIO(0xA088)
 #define GEN6_RC_STATE				_MMIO(0xA094)
+#define RC6_STATE				(1<<18)
 #define GEN6_RC1_WAKE_RATE_LIMIT		_MMIO(0xA098)
 #define GEN6_RC6_WAKE_RATE_LIMIT		_MMIO(0xA09C)
 #define GEN6_RC6pp_WAKE_RATE_LIMIT		_MMIO(0xA0A0)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 0438b57..f22baef 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1564,6 +1564,7 @@ void skl_wm_get_hw_state(struct drm_device *dev);
 void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
 			  struct skl_ddb_allocation *ddb /* out */);
 uint32_t ilk_pipe_pixel_rate(const struct intel_crtc_state *pipe_config);
+int sanitize_rc6_option(const struct drm_device *dev, int enable_rc6);
 
 /* intel_sdvo.c */
 bool intel_sdvo_init(struct drm_device *dev,
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 02fe081..c9a32a4 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4518,12 +4518,68 @@ static void intel_print_rc6_info(struct drm_device *dev, u32 mode)
 			      (mode & GEN6_RC_CTL_RC6_ENABLE) ? "on" : "off");
 }
 
-static int sanitize_rc6_option(const struct drm_device *dev, int enable_rc6)
+static bool bxt_check_bios_rc6_setup(const struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	bool enable_rc6 = true;
+	unsigned long rc6_ctx_base;
+	bool bios_hw_rc6_enabled, bios_sw_rc6_enabled;
+
+	bios_hw_rc6_enabled = I915_READ(GEN6_RC_CONTROL) &
+				(GEN6_RC_CTL_RC6_ENABLE |
+					GEN6_RC_CTL_HW_ENABLE);
+	bios_sw_rc6_enabled = !(I915_READ(GEN6_RC_CONTROL) &
+				GEN6_RC_CTL_HW_ENABLE) &&
+				(I915_READ(GEN6_RC_STATE) & RC6_STATE);
+
+	if (!(I915_READ(RC6_LOCATION) & RC6_CTX_IN_DRAM)) {
+		DRM_DEBUG_KMS("RC6 Base location not set properly.\n");
+		enable_rc6 = false;
+	}
+
+	rc6_ctx_base = I915_READ(RC6_CTX_BASE) & RC6_CTX_BASE_MASK;
+	if (!((rc6_ctx_base >= dev_priv->gtt.stolen_reserved_base) &&
+		(rc6_ctx_base <= (dev_priv->gtt.stolen_reserved_base +
+					dev_priv->gtt.stolen_reserved_size)))) {
+		DRM_DEBUG_KMS("RC6 Base address not as expected.\n");
+		enable_rc6 = false;
+	}
+
+	if (!(((I915_READ(PWRCTX_MAXCNT_RCSUNIT) & IDLE_TIME_MASK) > 1) &&
+	      ((I915_READ(PWRCTX_MAXCNT_VCSUNIT0) & IDLE_TIME_MASK) > 1) &&
+	      ((I915_READ(PWRCTX_MAXCNT_BCSUNIT) & IDLE_TIME_MASK) > 1) &&
+	      ((I915_READ(PWRCTX_MAXCNT_VECSUNIT) & IDLE_TIME_MASK) > 1))) {
+		DRM_DEBUG_KMS("Engine Idle wait time not set properly.\n");
+		enable_rc6 = false;
+	}
+
+	if (HAS_BSD2(dev) &&
+		((I915_READ(PWRCTX_MAXCNT_VCSUNIT1) & IDLE_TIME_MASK) > 1)) {
+		DRM_DEBUG_KMS("VCSUNIT1 Idle wait time not set properly.\n");
+		enable_rc6 = false;
+	}
+
+	if (!bios_hw_rc6_enabled && !bios_sw_rc6_enabled) {
+		DRM_DEBUG_KMS("HW/SW RC6 is not enabled by BIOS.\n");
+		enable_rc6 = false;
+	}
+
+	return enable_rc6;
+}
+
+int sanitize_rc6_option(const struct drm_device *dev, int enable_rc6)
 {
 	/* No RC6 before Ironlake and code is gone for ilk. */
 	if (INTEL_INFO(dev)->gen < 6)
 		return 0;
 
+	if (IS_BROXTON(dev)) {
+		if (!bxt_check_bios_rc6_setup(dev)) {
+			DRM_INFO("RC6 disabled by BIOS\n");
+			return 0;
+		}
+	}
+
 	/* Respect the kernel parameter if it is set */
 	if (enable_rc6 >= 0) {
 		int mask;
@@ -6014,7 +6070,6 @@ void intel_init_gt_powersave(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	i915.enable_rc6 = sanitize_rc6_option(dev, i915.enable_rc6);
 	/*
 	 * RPM depends on RC6 to save restore the GT HW context, so make RC6 a
 	 * requirement.
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 277e60a..43fc3e8 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -359,6 +359,10 @@ void intel_uncore_early_sanitize(struct drm_device *dev, bool restore_forcewake)
 
 void intel_uncore_sanitize(struct drm_device *dev)
 {
+	i915_gem_init_stolen_reserved(dev);
+
+	i915.enable_rc6 = sanitize_rc6_option(dev, i915.enable_rc6);
+
 	/* BIOS often leaves RC6 enabled, but disable it for hw init */
 	intel_disable_gt_powersave(dev);
 }
-- 
1.9.1



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