[Intel-gfx] [RFCv3 3/3] drm/i915: Introduce per-platform PPAT configurations

Zhi Wang zhi.a.wang at intel.com
Wed Aug 23 01:44:13 UTC 2017


The previous static PPAT configuration for each platform is kept unchanged
and now configured through intel_ppat_reserve(). Also the PPAT feature of
each platform is described in intel PPAT instance during the initialization
and related callbacks which supports the PPAT management framework will be
hooked.

Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 145 ++++++++++++++++++++++++------------
 1 file changed, 96 insertions(+), 49 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 2a521b6..d103ea4 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2857,41 +2857,92 @@ void intel_ppat_put(struct intel_ppat_entry *entry)
 	kref_put(&entry->ref_count, put_ppat);
 }
 
-static void cnl_setup_private_ppat(struct drm_i915_private *dev_priv)
+static void cnl_private_pat_update(struct drm_i915_private *dev_priv)
 {
+	struct intel_ppat *ppat = &dev_priv->ppat;
+	int i;
+
+	for (i = 0; i < ppat->max_entries; i++)
+		I915_WRITE(GEN10_PAT_INDEX(i), ppat->entries[i].value);
+}
+
+static void bdw_private_pat_update(struct drm_i915_private *dev_priv)
+{
+	struct intel_ppat *ppat = &dev_priv->ppat;
+	u64 pat = 0;
+	int i;
+
+	for (i = 0; i < ppat->max_entries; i++)
+		pat |= GEN8_PPAT(i, ppat->entries[i].value);
+
+	I915_WRITE(GEN8_PRIVATE_PAT_LO, pat);
+	I915_WRITE(GEN8_PRIVATE_PAT_HI, pat >> 32);
+}
+
+#define gen8_pat_ca(v) ((v) & 0x3)
+#define gen8_pat_tc(v) (((v) >> 2) & 0x3)
+#define gen8_pat_age(v) (((v) >> 4) & 0x3)
+
+static unsigned int bdw_private_pat_match(u8 src, u8 dst)
+{
+	unsigned int score = 0;
+
+	/* Cache attribute has to be matched. */
+	if (gen8_pat_ca(src) != gen8_pat_ca(dst))
+		return 0;
+
+	if (gen8_pat_age(src) == gen8_pat_age(dst))
+		score += 1;
+
+	if (gen8_pat_tc(src) == gen8_pat_tc(dst))
+		score += 2;
+
+	if (score == 3)
+		return ~0;
+
+	return score;
+}
+
+#define chv_get_snoop(v) (((v) >> 6) & 0x1)
+
+static unsigned int chv_private_pat_match(u8 src, u8 dst)
+{
+	if (chv_get_snoop(src) == chv_get_snoop(dst))
+		return ~0;
+
+	return 0;
+}
+
+static void cnl_setup_private_ppat(struct intel_ppat *ppat)
+{
+	ppat->max_entries = 8;
+	ppat->update = cnl_private_pat_update;
+	ppat->match = bdw_private_pat_match;
+	ppat->dummy_value = GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3);
+
 	/* XXX: spec is unclear if this is still needed for CNL+ */
 	if (!USES_PPGTT(dev_priv)) {
-		I915_WRITE(GEN10_PAT_INDEX(0), GEN8_PPAT_UC);
+		intel_ppat_reserve(ppat, 0, GEN8_PPAT_UC);
 		return;
 	}
 
-	I915_WRITE(GEN10_PAT_INDEX(0), GEN8_PPAT_WB | GEN8_PPAT_LLC);
-	I915_WRITE(GEN10_PAT_INDEX(1), GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
-	I915_WRITE(GEN10_PAT_INDEX(2), GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);
-	I915_WRITE(GEN10_PAT_INDEX(3), GEN8_PPAT_UC);
-	I915_WRITE(GEN10_PAT_INDEX(4), GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
-	I915_WRITE(GEN10_PAT_INDEX(5), GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
-	I915_WRITE(GEN10_PAT_INDEX(6), GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
-	I915_WRITE(GEN10_PAT_INDEX(7), GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
+	intel_ppat_reserve(ppat, 0, GEN8_PPAT_WB | GEN8_PPAT_LLC);
+	intel_ppat_reserve(ppat, 1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
+	intel_ppat_reserve(ppat, 2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);
+	intel_ppat_reserve(ppat, 3, GEN8_PPAT_UC);
 }
 
 /* The GGTT and PPGTT need a private PPAT setup in order to handle cacheability
  * bits. When using advanced contexts each context stores its own PAT, but
  * writing this data shouldn't be harmful even in those cases. */
-static void bdw_setup_private_ppat(struct drm_i915_private *dev_priv)
+static void bdw_setup_private_ppat(struct intel_ppat *ppat)
 {
-	u64 pat;
+	ppat->max_entries = 8;
+	ppat->update = bdw_private_pat_update;
+	ppat->match = bdw_private_pat_match;
+	ppat->dummy_value = GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3);
 
-	pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC)     | /* for normal objects, no eLLC */
-	      GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) | /* for something pointing to ptes? */
-	      GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC) | /* for scanout with eLLC */
-	      GEN8_PPAT(3, GEN8_PPAT_UC)                     | /* Uncached objects, mostly for scanout */
-	      GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) |
-	      GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) |
-	      GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) |
-	      GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
-
-	if (!USES_PPGTT(dev_priv))
+	if (!USES_PPGTT(dev_priv)) {
 		/* Spec: "For GGTT, there is NO pat_sel[2:0] from the entry,
 		 * so RTL will always use the value corresponding to
 		 * pat_sel = 000".
@@ -2905,17 +2956,22 @@ static void bdw_setup_private_ppat(struct drm_i915_private *dev_priv)
 		 * So we can still hold onto all our assumptions wrt cpu
 		 * clflushing on LLC machines.
 		 */
-		pat = GEN8_PPAT(0, GEN8_PPAT_UC);
+		intel_ppat_reserve(ppat, 0, GEN8_PPAT_UC);
+		return;
+	}
 
-	/* XXX: spec defines this as 2 distinct registers. It's unclear if a 64b
-	 * write would work. */
-	I915_WRITE(GEN8_PRIVATE_PAT_LO, pat);
-	I915_WRITE(GEN8_PRIVATE_PAT_HI, pat >> 32);
+	intel_ppat_reserve(ppat, 0, GEN8_PPAT_WB | GEN8_PPAT_LLC);     /* for normal objects, no eLLC */
+	intel_ppat_reserve(ppat, 1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC); /* for something pointing to ptes? */
+	intel_ppat_reserve(ppat, 2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC); /* for scanout with eLLC */
+	intel_ppat_reserve(ppat, 3, GEN8_PPAT_UC);		       /* Uncached objects, mostly for scanout */
 }
 
-static void chv_setup_private_ppat(struct drm_i915_private *dev_priv)
+static void chv_setup_private_ppat(struct intel_ppat *ppat)
 {
-	u64 pat;
+	ppat->max_entries = 8;
+	ppat->update = bdw_private_pat_update;
+	ppat->match = chv_private_pat_match;
+	ppat->dummy_value = CHV_PPAT_SNOOP;
 
 	/*
 	 * Map WB on BDW to snooped on CHV.
@@ -2935,17 +2991,11 @@ static void chv_setup_private_ppat(struct drm_i915_private *dev_priv)
 	 * Which means we must set the snoop bit in PAT entry 0
 	 * in order to keep the global status page working.
 	 */
-	pat = GEN8_PPAT(0, CHV_PPAT_SNOOP) |
-	      GEN8_PPAT(1, 0) |
-	      GEN8_PPAT(2, 0) |
-	      GEN8_PPAT(3, 0) |
-	      GEN8_PPAT(4, CHV_PPAT_SNOOP) |
-	      GEN8_PPAT(5, CHV_PPAT_SNOOP) |
-	      GEN8_PPAT(6, CHV_PPAT_SNOOP) |
-	      GEN8_PPAT(7, CHV_PPAT_SNOOP);
 
-	I915_WRITE(GEN8_PRIVATE_PAT_LO, pat);
-	I915_WRITE(GEN8_PRIVATE_PAT_HI, pat >> 32);
+	intel_ppat_reserve(ppat, 0, CHV_PPAT_SNOOP);
+	intel_ppat_reserve(ppat, 1, 0);
+	intel_ppat_reserve(ppat, 2, 0);
+	intel_ppat_reserve(ppat, 3, 0);
 }
 
 static void gen6_gmch_remove(struct i915_address_space *vm)
@@ -2963,20 +3013,23 @@ static void setup_private_pat(struct drm_i915_private *dev_priv)
 
 	ppat->dev_priv = dev_priv;
 
+	/* Load per-platform PPAT configurations */
 	if (INTEL_GEN(dev_priv) >= 10)
-		cnl_setup_private_ppat(dev_priv);
+		cnl_setup_private_ppat(ppat);
 	else if (IS_CHERRYVIEW(dev_priv) || IS_GEN9_LP(dev_priv))
-		chv_setup_private_ppat(dev_priv);
+		chv_setup_private_ppat(ppat);
 	else
-		bdw_setup_private_ppat(dev_priv);
+		bdw_setup_private_ppat(ppat);
 
 	GEM_BUG_ON(ppat->max_entries > INTEL_MAX_PPAT_ENTRIES);
 
+	/* Fill unused PPAT entries with dummy PPAT value */
 	for_each_clear_bit(i, ppat->reserved, ppat->max_entries) {
 		ppat->entries[i].value = ppat->dummy_value;
 		ppat->entries[i].ppat = ppat;
 	}
 
+	/* Write the HW */
 	ppat->update(dev_priv);
 }
 
@@ -3291,13 +3344,7 @@ void i915_gem_restore_gtt_mappings(struct drm_i915_private *dev_priv)
 	ggtt->base.closed = false;
 
 	if (INTEL_GEN(dev_priv) >= 8) {
-		if (INTEL_GEN(dev_priv) >= 10)
-			cnl_setup_private_ppat(dev_priv);
-		else if (IS_CHERRYVIEW(dev_priv) || IS_GEN9_LP(dev_priv))
-			chv_setup_private_ppat(dev_priv);
-		else
-			bdw_setup_private_ppat(dev_priv);
-
+		dev_priv->ppat.update(dev_priv);
 		return;
 	}
 
-- 
2.7.4



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