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>

1 files changed, 78 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index ae1ba47e4ef0..20b4b7924f51 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/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);