[Intel-gfx] [PATCH v8 5/7] drm/i915: keep track of used entries in MOCS table

Lucas De Marchi lucas.demarchi at intel.com
Tue Jan 22 05:12:25 UTC 2019


Instead of considering we have defined entries for any index in the
table, let's keep track of the ones we explicitly defined. This will
allow Gen 11 to have it's new table defined in which we have holes of
undefined entries.

Repeated comments about the meaning of undefined entries were removed
since they are overly verbose and copy-pasted in several functions: now
the definition is in the top only.

Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/intel_mocs.c | 88 ++++++++++++++++++++-----------
 1 file changed, 57 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_mocs.c b/drivers/gpu/drm/i915/intel_mocs.c
index faae2eefc5cc..af2ae2f396ae 100644
--- a/drivers/gpu/drm/i915/intel_mocs.c
+++ b/drivers/gpu/drm/i915/intel_mocs.c
@@ -28,6 +28,7 @@
 struct drm_i915_mocs_entry {
 	u32 control_value;
 	u16 l3cc_value;
+	u16 used;
 };
 
 struct drm_i915_mocs_table {
@@ -75,6 +76,7 @@ struct drm_i915_mocs_table {
 	[__idx] = { \
 		.control_value = __control_value, \
 		.l3cc_value = __l3cc_value, \
+		.used = 1, \
 	}
 
 /*
@@ -195,24 +197,26 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
 	struct drm_i915_private *dev_priv = engine->i915;
 	struct drm_i915_mocs_table table;
 	unsigned int index;
+	u32 unused_value;
 
 	if (!get_mocs_settings(dev_priv, &table))
 		return;
 
 	GEM_BUG_ON(table.size > GEN9_NUM_MOCS_ENTRIES);
 
-	for (index = 0; index < table.size; index++)
-		I915_WRITE(mocs_register(engine->id, index),
-			   table.table[index].control_value);
+	/* Set unused values to PTE */
+	unused_value = table.table[I915_MOCS_PTE].control_value;
 
-	/*
-	 * Now set the unused entries to PTE. These entries are officially
-	 * undefined and no contract for the contents and settings is given
-	 * for these entries.
-	 */
+	for (index = 0; index < table.size; index++) {
+		u32 value = table.table[index].used ?
+			table.table[index].control_value : unused_value;
+
+		I915_WRITE(mocs_register(engine->id, index), value);
+	}
+
+	/* All remaining entries are also unused */
 	for (; index < GEN9_NUM_MOCS_ENTRIES; index++)
-		I915_WRITE(mocs_register(engine->id, index),
-			   table.table[I915_MOCS_PTE].control_value);
+		I915_WRITE(mocs_register(engine->id, index), unused_value);
 }
 
 /**
@@ -230,11 +234,15 @@ static int emit_mocs_control_table(struct i915_request *rq,
 {
 	enum intel_engine_id engine = rq->engine->id;
 	unsigned int index;
+	u32 unused_value;
 	u32 *cs;
 
 	if (WARN_ON(table->size > GEN9_NUM_MOCS_ENTRIES))
 		return -ENODEV;
 
+	/* Set unused values to PTE */
+	unused_value = table->table[I915_MOCS_PTE].control_value;
+
 	cs = intel_ring_begin(rq, 2 + 2 * GEN9_NUM_MOCS_ENTRIES);
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
@@ -242,18 +250,17 @@ static int emit_mocs_control_table(struct i915_request *rq,
 	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_NUM_MOCS_ENTRIES);
 
 	for (index = 0; index < table->size; index++) {
+		u32 value = table->table[index].used ?
+			table->table[index].control_value : unused_value;
+
 		*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
-		*cs++ = table->table[index].control_value;
+		*cs++ = value;
 	}
 
-	/*
-	 * Now set the unused entries to PTE. These entries are officially
-	 * undefined and no contract for the contents and settings is given
-	 * for these entries.
-	 */
+	/* All remaining entries are also unused */
 	for (; index < GEN9_NUM_MOCS_ENTRIES; index++) {
 		*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
-		*cs++ = table->table[I915_MOCS_PTE].control_value;
+		*cs++ = unused_value;
 	}
 
 	*cs++ = MI_NOOP;
@@ -284,12 +291,15 @@ static inline u32 l3cc_combine(const struct drm_i915_mocs_table *table,
 static int emit_mocs_l3cc_table(struct i915_request *rq,
 				const struct drm_i915_mocs_table *table)
 {
-	unsigned int i;
+	unsigned int i, unused_index;
 	u32 *cs;
 
 	if (WARN_ON(table->size > GEN9_NUM_MOCS_ENTRIES))
 		return -ENODEV;
 
+	/* Set unused values to PTE */
+	unused_index = I915_MOCS_PTE;
+
 	cs = intel_ring_begin(rq, 2 + GEN9_NUM_MOCS_ENTRIES);
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
@@ -297,25 +307,29 @@ static int emit_mocs_l3cc_table(struct i915_request *rq,
 	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_NUM_MOCS_ENTRIES / 2);
 
 	for (i = 0; i < table->size / 2; i++) {
+		u16 low = table->table[2 * i].used ?
+			2 * i : unused_index;
+		u16 high = table->table[2 * i + 1].used ?
+			2 * i + 1 : unused_index;
+
 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
-		*cs++ = l3cc_combine(table, 2 * i, 2 * i + 1);
+		*cs++ = l3cc_combine(table, low, high);
 	}
 
 	if (table->size & 0x01) {
+		u16 low = table->table[2 * i].used ?
+			2 * i : unused_index;
+
 		/* Odd table size - 1 left over */
 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
-		*cs++ = l3cc_combine(table, 2 * i, I915_MOCS_PTE);
+		*cs++ = l3cc_combine(table, low, unused_index);
 		i++;
 	}
 
-	/*
-	 * Now set the unused entries to PTE. These entries are officially
-	 * undefined and no contract for the contents and settings is given
-	 * for these entries.
-	 */
+	/* All remaining entries are also unused */
 	for (; i < GEN9_NUM_MOCS_ENTRIES / 2; i++) {
 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
-		*cs++ = l3cc_combine(table, I915_MOCS_PTE, I915_MOCS_PTE);
+		*cs++ = l3cc_combine(table, unused_index, unused_index);
 	}
 
 	*cs++ = MI_NOOP;
@@ -341,26 +355,38 @@ static int emit_mocs_l3cc_table(struct i915_request *rq,
 void intel_mocs_init_l3cc_table(struct drm_i915_private *dev_priv)
 {
 	struct drm_i915_mocs_table table;
-	unsigned int i;
+	unsigned int i, unused_index;
 
 	if (!get_mocs_settings(dev_priv, &table))
 		return;
 
-	for (i = 0; i < table.size / 2; i++)
+	/* Set unused values to PTE */
+	unused_index = I915_MOCS_PTE;
+
+	for (i = 0; i < table.size / 2; i++) {
+		u16 low = table.table[2 * i].used ?
+			2 * i : unused_index;
+		u16 high = table.table[2 * i + 1].used ?
+			2 * i + 1 : unused_index;
+
 		I915_WRITE(GEN9_LNCFCMOCS(i),
-			   l3cc_combine(&table, 2 * i, 2 * i + 1));
+			   l3cc_combine(&table, low, high));
+	}
 
 	/* Odd table size - 1 left over */
 	if (table.size & 0x01) {
+		u16 low = table.table[2 * i].used ?
+			2 * i : unused_index;
+
 		I915_WRITE(GEN9_LNCFCMOCS(i),
-			   l3cc_combine(&table, 2 * i, I915_MOCS_PTE));
+			   l3cc_combine(&table, low, unused_index));
 		i++;
 	}
 
 	/* Now set the rest of the table to PTE */
 	for (; i < (GEN9_NUM_MOCS_ENTRIES / 2); i++)
 		I915_WRITE(GEN9_LNCFCMOCS(i),
-			   l3cc_combine(&table, I915_MOCS_PTE, I915_MOCS_PTE));
+			   l3cc_combine(&table, unused_index, unused_index));
 }
 
 /**
-- 
2.20.0



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