drm/i915/bdw: Check for slice, subslice and EU count for BDW

Added checks for available slices, subslices and EUs for Broadwell. This
information is filled in intel_device_info and is available to user with
GET_PARAM.
Added checks for enabled slices, subslices and EU for Broadwell. This
information is based on available counts but takes power gated slices
into account. It can be read in debugfs.
Introduce new register defines that contain information on slices on
Broadwell.

v2:
- Introduce GT_SLICE_INFO register
- Change Broadwell sseu_device_status function to use GT_SLICE_INFO
  register instead of RPCS register
- Undo removal of dev_priv variables in Cherryview and Gen9
  sseu_device_satus functions

v3:
- Fix style issues

v4:
- Corrected comment
- Reverted reordering of defines

Cc: Jeff Mcgee <jeff.mcgee@intel.com>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Łukasz Daniluk <lukasz.daniluk@intel.com>
Reviewed-by: Jeff McGee <jeff.mcgee@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -5048,13 +5048,38 @@ static void gen9_sseu_device_status(struct drm_device *dev,
 	}
 }
 
+static void broadwell_sseu_device_status(struct drm_device *dev,
+					 struct sseu_dev_status *stat)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int s;
+	u32 slice_info = I915_READ(GEN8_GT_SLICE_INFO);
+
+	stat->slice_total = hweight32(slice_info & GEN8_LSLICESTAT_MASK);
+
+	if (stat->slice_total) {
+		stat->subslice_per_slice = INTEL_INFO(dev)->subslice_per_slice;
+		stat->subslice_total = stat->slice_total *
+				       stat->subslice_per_slice;
+		stat->eu_per_subslice = INTEL_INFO(dev)->eu_per_subslice;
+		stat->eu_total = stat->eu_per_subslice * stat->subslice_total;
+
+		/* subtract fused off EU(s) from enabled slice(s) */
+		for (s = 0; s < stat->slice_total; s++) {
+			u8 subslice_7eu = INTEL_INFO(dev)->subslice_7eu[s];
+
+			stat->eu_total -= hweight8(subslice_7eu);
+		}
+	}
+}
+
 static int i915_sseu_status(struct seq_file *m, void *unused)
 {
 	struct drm_info_node *node = (struct drm_info_node *) m->private;
 	struct drm_device *dev = node->minor->dev;
 	struct sseu_dev_status stat;
 
-	if ((INTEL_INFO(dev)->gen < 8) || IS_BROADWELL(dev))
+	if (INTEL_INFO(dev)->gen < 8)
 		return -ENODEV;
 
 	seq_puts(m, "SSEU Device Info\n");
@@ -5079,6 +5104,8 @@ static int i915_sseu_status(struct seq_file *m, void *unused)
 	memset(&stat, 0, sizeof(stat));
 	if (IS_CHERRYVIEW(dev)) {
 		cherryview_sseu_device_status(dev, &stat);
+	} else if (IS_BROADWELL(dev)) {
+		broadwell_sseu_device_status(dev, &stat);
 	} else if (INTEL_INFO(dev)->gen >= 9) {
 		gen9_sseu_device_status(dev, &stat);
 	}

drivers/gpu/drm/i915/i915_dma.c

@@ -702,6 +702,82 @@ static void gen9_sseu_info_init(struct drm_device *dev)
 	info->has_eu_pg = (info->eu_per_subslice > 2);
 }
 
+static void broadwell_sseu_info_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_device_info *info;
+	const int s_max = 3, ss_max = 3, eu_max = 8;
+	int s, ss;
+	u32 fuse2, eu_disable[s_max], s_enable, ss_disable;
+
+	fuse2 = I915_READ(GEN8_FUSE2);
+	s_enable = (fuse2 & GEN8_F2_S_ENA_MASK) >> GEN8_F2_S_ENA_SHIFT;
+	ss_disable = (fuse2 & GEN8_F2_SS_DIS_MASK) >> GEN8_F2_SS_DIS_SHIFT;
+
+	eu_disable[0] = I915_READ(GEN8_EU_DISABLE0) & GEN8_EU_DIS0_S0_MASK;
+	eu_disable[1] = (I915_READ(GEN8_EU_DISABLE0) >> GEN8_EU_DIS0_S1_SHIFT) |
+			((I915_READ(GEN8_EU_DISABLE1) & GEN8_EU_DIS1_S1_MASK) <<
+			 (32 - GEN8_EU_DIS0_S1_SHIFT));
+	eu_disable[2] = (I915_READ(GEN8_EU_DISABLE1) >> GEN8_EU_DIS1_S2_SHIFT) |
+			((I915_READ(GEN8_EU_DISABLE2) & GEN8_EU_DIS2_S2_MASK) <<
+			 (32 - GEN8_EU_DIS1_S2_SHIFT));
+
+
+	info = (struct intel_device_info *)&dev_priv->info;
+	info->slice_total = hweight32(s_enable);
+
+	/*
+	 * The subslice disable field is global, i.e. it applies
+	 * to each of the enabled slices.
+	 */
+	info->subslice_per_slice = ss_max - hweight32(ss_disable);
+	info->subslice_total = info->slice_total * info->subslice_per_slice;
+
+	/*
+	 * Iterate through enabled slices and subslices to
+	 * count the total enabled EU.
+	 */
+	for (s = 0; s < s_max; s++) {
+		if (!(s_enable & (0x1 << s)))
+			/* skip disabled slice */
+			continue;
+
+		for (ss = 0; ss < ss_max; ss++) {
+			u32 n_disabled;
+
+			if (ss_disable & (0x1 << ss))
+				/* skip disabled subslice */
+				continue;
+
+			n_disabled = hweight8(eu_disable[s] >> (ss * eu_max));
+
+			/*
+			 * Record which subslices have 7 EUs.
+			 */
+			if (eu_max - n_disabled == 7)
+				info->subslice_7eu[s] |= 1 << ss;
+
+			info->eu_total += eu_max - n_disabled;
+		}
+	}
+
+	/*
+	 * BDW is expected to always have a uniform distribution of EU across
+	 * subslices with the exception that any one EU in any one subslice may
+	 * be fused off for die recovery.
+	 */
+	info->eu_per_subslice = info->subslice_total ?
+		DIV_ROUND_UP(info->eu_total, info->subslice_total) : 0;
+
+	/*
+	 * BDW supports slice power gating on devices with more than
+	 * one slice.
+	 */
+	info->has_slice_pg = (info->slice_total > 1);
+	info->has_subslice_pg = 0;
+	info->has_eu_pg = 0;
+}
+
 /*
  * Determine various intel_device_info fields at runtime.
  *
@@ -772,6 +848,8 @@ static void intel_device_info_runtime_init(struct drm_device *dev)
 	/* Initialize slice/subslice/EU info */
 	if (IS_CHERRYVIEW(dev))
 		cherryview_sseu_info_init(dev);
+	else if (IS_BROADWELL(dev))
+		broadwell_sseu_info_init(dev);
 	else if (INTEL_INFO(dev)->gen >= 9)
 		gen9_sseu_info_init(dev);
 

drivers/gpu/drm/i915/i915_reg.h

@@ -1887,12 +1887,27 @@ enum skl_disp_power_wells {
 #define   CHV_FGT_EU_DIS_SS1_R1_MASK	(0xf << CHV_FGT_EU_DIS_SS1_R1_SHIFT)
 
 #define GEN8_FUSE2			0x9120
+#define   GEN8_F2_SS_DIS_SHIFT		21
+#define   GEN8_F2_SS_DIS_MASK		(0x7 << GEN8_F2_SS_DIS_SHIFT)
 #define   GEN8_F2_S_ENA_SHIFT		25
 #define   GEN8_F2_S_ENA_MASK		(0x7 << GEN8_F2_S_ENA_SHIFT)
 
 #define   GEN9_F2_SS_DIS_SHIFT		20
 #define   GEN9_F2_SS_DIS_MASK		(0xf << GEN9_F2_SS_DIS_SHIFT)
 
+#define GEN8_EU_DISABLE0		0x9134
+#define   GEN8_EU_DIS0_S0_MASK		0xffffff
+#define   GEN8_EU_DIS0_S1_SHIFT		24
+#define   GEN8_EU_DIS0_S1_MASK		(0xff << GEN8_EU_DIS0_S1_SHIFT)
+
+#define GEN8_EU_DISABLE1		0x9138
+#define   GEN8_EU_DIS1_S1_MASK		0xffff
+#define   GEN8_EU_DIS1_S2_SHIFT		16
+#define   GEN8_EU_DIS1_S2_MASK		(0xffff << GEN8_EU_DIS1_S2_SHIFT)
+
+#define GEN8_EU_DISABLE2		0x913c
+#define   GEN8_EU_DIS2_S2_MASK		0xff
+
 #define GEN9_EU_DISABLE(slice)		(0x9134 + (slice)*0x4)
 
 #define GEN6_BSD_SLEEP_PSMI_CONTROL	0x12050
@@ -6885,6 +6900,9 @@ enum skl_disp_power_wells {
 #define   GEN6_RC6			3
 #define   GEN6_RC7			4
 
+#define GEN8_GT_SLICE_INFO		0x138064
+#define   GEN8_LSLICESTAT_MASK		0x7
+
 #define CHV_POWER_SS0_SIG1		0xa720
 #define CHV_POWER_SS1_SIG1		0xa728
 #define   CHV_SS_PG_ENABLE		(1<<1)