[PATCH 1/3] drm/i915/guc: Provide mmio list to be saved/restored on engine reset

Fernando Pacheco fernando.pacheco at intel.com
Thu Nov 21 22:13:21 UTC 2019


The driver must provide GuC with a list of mmio registers
that should be saved/restored during a GuC-based engine reset.
We provide a minimal set of registers that should get things
working and extend as needed.

The mmio list is built using separate lists within the driver.
It's possible that at some point we may attempt to add the same
register more than once. Do not consider this an error; silently
move on if the register is already in the list.

Signed-off-by: Fernando Pacheco <fernando.pacheco at intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c   | 23 +++--
 .../gpu/drm/i915/gt/intel_workarounds_types.h |  1 +
 drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c    | 90 ++++++++++++++++++-
 3 files changed, 107 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 226bd4cccb48..964d6fe8bf5c 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -147,23 +147,31 @@ static void _wa_add(struct i915_wa_list *wal, const struct i915_wa *wa)
 }
 
 static void
-wa_write_masked_or(struct i915_wa_list *wal, i915_reg_t reg, u32 mask,
-		   u32 val)
+__wa_write_masked_or(struct i915_wa_list *wal, i915_reg_t reg, u32 mask,
+		     u32 val, bool masked_bits)
 {
 	struct i915_wa wa = {
 		.reg  = reg,
 		.mask = mask,
 		.val  = val,
 		.read = mask,
+		.masked_bits = masked_bits,
 	};
 
 	_wa_add(wal, &wa);
 }
 
+static void
+wa_write_masked_or(struct i915_wa_list *wal, i915_reg_t reg, u32 mask,
+		   u32 val)
+{
+	__wa_write_masked_or(wal, reg, mask, val, false);
+}
+
 static void
 wa_masked_en(struct i915_wa_list *wal, i915_reg_t reg, u32 val)
 {
-	wa_write_masked_or(wal, reg, val, _MASKED_BIT_ENABLE(val));
+	__wa_write_masked_or(wal, reg, val, _MASKED_BIT_ENABLE(val), true);
 }
 
 static void
@@ -179,13 +187,16 @@ wa_write_or(struct i915_wa_list *wal, i915_reg_t reg, u32 val)
 }
 
 #define WA_SET_BIT_MASKED(addr, mask) \
-	wa_write_masked_or(wal, (addr), (mask), _MASKED_BIT_ENABLE(mask))
+	__wa_write_masked_or(wal, (addr), (mask), \
+			     _MASKED_BIT_ENABLE(mask), true)
 
 #define WA_CLR_BIT_MASKED(addr, mask) \
-	wa_write_masked_or(wal, (addr), (mask), _MASKED_BIT_DISABLE(mask))
+	__wa_write_masked_or(wal, (addr), (mask), \
+			     _MASKED_BIT_DISABLE(mask), true)
 
 #define WA_SET_FIELD_MASKED(addr, mask, value) \
-	wa_write_masked_or(wal, (addr), (mask), _MASKED_FIELD((mask), (value)))
+	__wa_write_masked_or(wal, (addr), (mask), \
+			     _MASKED_FIELD((mask), (value)), true)
 
 static void gen8_ctx_workarounds_init(struct intel_engine_cs *engine,
 				      struct i915_wa_list *wal)
diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds_types.h b/drivers/gpu/drm/i915/gt/intel_workarounds_types.h
index e27ab1b710b3..a43d5f968f2d 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds_types.h
@@ -16,6 +16,7 @@ struct i915_wa {
 	u32		mask;
 	u32		val;
 	u32		read;
+	bool		masked_bits;
 };
 
 struct i915_wa_list {
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c
index ca6674b8e00c..177cbfbb40e7 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c
@@ -3,6 +3,8 @@
  * Copyright © 2014-2019 Intel Corporation
  */
 
+#include <linux/bsearch.h>
+
 #include "gt/intel_gt.h"
 #include "intel_guc_ads.h"
 #include "intel_uc.h"
@@ -16,6 +18,9 @@
  * its internal state for sleep.
  */
 
+static void guc_mmio_reg_state_init(struct guc_mmio_reg_state *reg_state,
+				    struct intel_engine_cs *engine);
+
 static void guc_policy_init(struct guc_policy *policy)
 {
 	policy->execution_quantum = POLICY_DEFAULT_EXECUTION_QUANTUM_US;
@@ -67,12 +72,19 @@ struct __guc_ads_blob {
 
 static void __guc_ads_init(struct intel_guc *guc)
 {
-	struct drm_i915_private *dev_priv = guc_to_gt(guc)->i915;
+	struct intel_gt *gt = guc_to_gt(guc);
+	struct drm_i915_private *dev_priv = gt->i915;
 	struct __guc_ads_blob *blob = guc->ads_blob;
 	const u32 skipped_size = LRC_PPHWSP_SZ * PAGE_SIZE + LR_HW_CONTEXT_SIZE;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
 	u32 base;
 	u8 engine_class;
 
+	/* GuC mmio save/restore list */
+	for_each_engine(engine, gt, id)
+		guc_mmio_reg_state_init(&blob->reg_state, engine);
+
 	/* GuC scheduling policies */
 	guc_policies_init(&blob->policies);
 
@@ -182,3 +194,79 @@ void intel_guc_ads_reset(struct intel_guc *guc)
 		return;
 	__guc_ads_init(guc);
 }
+
+static int guc_mmio_reg_cmp(const void *a, const void *b)
+{
+	const struct guc_mmio_reg *ra = a;
+	const struct guc_mmio_reg *rb = b;
+
+	return (int)ra->offset - (int)rb->offset;
+}
+
+static void guc_mmio_reg_add(struct guc_mmio_regset *regset,
+			     u32 offset, u32 flags)
+{
+	u32 count = regset->number_of_registers;
+	struct guc_mmio_reg reg = {
+		.offset = offset,
+		.flags = flags,
+	};
+	struct guc_mmio_reg *slot;
+
+	GEM_BUG_ON(count >= GUC_REGSET_MAX_REGISTERS);
+
+	if (bsearch(&reg, regset->registers, count,
+		    sizeof(reg), guc_mmio_reg_cmp))
+		return;
+
+	slot = &regset->registers[count];
+	regset->number_of_registers++;
+	*slot = reg;
+
+	while (slot-- > regset->registers) {
+		GEM_BUG_ON(slot[0].offset == slot[1].offset);
+		if (slot[1].offset > slot[0].offset)
+			break;
+
+		swap(slot[1], slot[0]);
+	}
+}
+
+#define GUC_MMIO_REG_ADD(regset, reg, masked) \
+	guc_mmio_reg_add(regset, \
+			 i915_mmio_reg_offset((reg)), \
+			 (masked) ? GUC_REGSET_MASKED : 0)
+
+static void guc_mmio_regset_init(struct guc_mmio_regset *regset,
+				 struct intel_engine_cs *engine)
+{
+	const u32 base = engine->mmio_base;
+	struct i915_wa_list *wal = &engine->wa_list;
+	struct i915_wa *wa;
+	unsigned int i;
+
+	GUC_MMIO_REG_ADD(regset, RING_MODE_GEN7(base), true);
+	GUC_MMIO_REG_ADD(regset, RING_HWS_PGA(base), false);
+	GUC_MMIO_REG_ADD(regset, RING_IMR(base), false);
+
+	for (i = 0, wa = wal->list; i < wal->count; i++, wa++)
+		GUC_MMIO_REG_ADD(regset, wa->reg, wa->masked_bits);
+
+	/* Be extra paranoid and include all whitelist registers. */
+	for (i = 0; i < RING_MAX_NONPRIV_SLOTS; i++)
+		GUC_MMIO_REG_ADD(regset,
+				 RING_FORCE_TO_NONPRIV(base, i),
+				 false);
+}
+
+static void guc_mmio_reg_state_init(struct guc_mmio_reg_state *reg_state,
+				    struct intel_engine_cs *engine)
+{
+	struct guc_mmio_regset *regset;
+
+	GEM_BUG_ON(engine->class >= GUC_MAX_ENGINE_CLASSES);
+	GEM_BUG_ON(engine->instance >= GUC_MAX_INSTANCES_PER_CLASS);
+	regset = &reg_state->engine_reg[engine->class][engine->instance];
+
+	guc_mmio_regset_init(regset, engine);
+}
-- 
2.24.0



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