Re: [Intel-gfx] [PATCH v2 2/6] drm/i915/uncore: Associate shadow table with uncore

Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx> · Tue, 21 Sep 2021 14:54:02 +0100

On 10/09/2021 21:10, Matt Roper wrote:
Store a reference to a platform's shadow table inside the uncore, the
same as we do with the forcewake table.  This will allow us to use a
single set of functions that operate on the shadow table reference
rather than generating lots of nearly-identical functions via macros
that differ only in terms of the table that they reference.

Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
---
  drivers/gpu/drm/i915/intel_uncore.c | 40 ++++++++++++++++++++---------
  drivers/gpu/drm/i915/intel_uncore.h |  7 +++++
  2 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 8c09af1e9f7a..5fa2bf26a948 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1026,17 +1026,19 @@ static int mmio_range_cmp(u32 key, const struct i915_range *range)
  		return 0;
  }
  
-#define __is_X_shadowed(x) \
-static bool is_##x##_shadowed(u32 offset) \
-{ \
-	const struct i915_range *regs = x##_shadowed_regs; \
-	return BSEARCH(offset, regs, ARRAY_SIZE(x##_shadowed_regs), \
+static bool
+is_shadowed(struct intel_uncore *uncore, u32 offset)

Fits in one line if you want.

+{
+	if (drm_WARN_ON(&uncore->i915->drm, !uncore->shadowed_reg_table))
+		return false;
+
+	return BSEARCH(offset,
+		       uncore->shadowed_reg_table,
+		       uncore->shadowed_reg_table_entries,
  		       mmio_range_cmp); \
  }
  
-__is_X_shadowed(gen8)
-__is_X_shadowed(gen11)
-__is_X_shadowed(gen12)
+

If you want to tidy.

  
  static enum forcewake_domains
  gen6_reg_write_fw_domains(struct intel_uncore *uncore, i915_reg_t reg)
@@ -1047,7 +1049,7 @@ gen6_reg_write_fw_domains(struct intel_uncore *uncore, i915_reg_t reg)
  #define __gen8_reg_write_fw_domains(uncore, offset) \
  ({ \
  	enum forcewake_domains __fwd; \
-	if (NEEDS_FORCE_WAKE(offset) && !is_gen8_shadowed(offset)) \
+	if (NEEDS_FORCE_WAKE(offset) && !is_shadowed(uncore, offset)) \
  		__fwd = FORCEWAKE_RENDER; \
  	else \
  		__fwd = 0; \
@@ -1081,7 +1083,7 @@ static const struct intel_forcewake_range __chv_fw_ranges[] = {
  #define __fwtable_reg_write_fw_domains(uncore, offset) \
  ({ \
  	enum forcewake_domains __fwd = 0; \
-	if (NEEDS_FORCE_WAKE((offset)) && !is_gen8_shadowed(offset)) \
+	if (NEEDS_FORCE_WAKE((offset)) && !is_shadowed(uncore, offset)) \
  		__fwd = find_fw_domain(uncore, offset); \
  	__fwd; \
  })
@@ -1090,7 +1092,7 @@ static const struct intel_forcewake_range __chv_fw_ranges[] = {
  ({ \
  	enum forcewake_domains __fwd = 0; \
  	const u32 __offset = (offset); \
-	if (!is_gen11_shadowed(__offset)) \
+	if (!is_shadowed(uncore, __offset)) \
  		__fwd = find_fw_domain(uncore, __offset); \
  	__fwd; \
  })
@@ -1099,7 +1101,7 @@ static const struct intel_forcewake_range __chv_fw_ranges[] = {
  ({ \
  	enum forcewake_domains __fwd = 0; \
  	const u32 __offset = (offset); \
-	if (!is_gen12_shadowed(__offset)) \
+	if (!is_shadowed(uncore, __offset)) \
  		__fwd = find_fw_domain(uncore, __offset); \
  	__fwd; \
  })
@@ -1705,6 +1707,7 @@ __gen_write(func, 8) \
  __gen_write(func, 16) \
  __gen_write(func, 32)
  
+

Ditto.

  __gen_reg_write_funcs(gen12_fwtable);
  __gen_reg_write_funcs(gen11_fwtable);
  __gen_reg_write_funcs(fwtable);
@@ -1969,6 +1972,12 @@ static int intel_uncore_fw_domains_init(struct intel_uncore *uncore)
  	(uncore)->fw_domains_table_entries = ARRAY_SIZE((d)); \
  }
  
+#define ASSIGN_SHADOW_TABLE(uncore, d) \
+{ \
+	(uncore)->shadowed_reg_table = d; \
+	(uncore)->shadowed_reg_table_entries = ARRAY_SIZE((d)); \
+}
+
  static int i915_pmic_bus_access_notifier(struct notifier_block *nb,
  					 unsigned long action, void *data)
  {
@@ -2081,30 +2090,37 @@ static int uncore_forcewake_init(struct intel_uncore *uncore)
  
  	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55)) {
  		ASSIGN_FW_DOMAINS_TABLE(uncore, __dg2_fw_ranges);
+		ASSIGN_SHADOW_TABLE(uncore, gen12_shadowed_regs);
  		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen12_fwtable);
  		ASSIGN_READ_MMIO_VFUNCS(uncore, gen11_fwtable);
  	} else if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50)) {
  		ASSIGN_FW_DOMAINS_TABLE(uncore, __xehp_fw_ranges);
+		ASSIGN_SHADOW_TABLE(uncore, gen12_shadowed_regs);
  		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen12_fwtable);
  		ASSIGN_READ_MMIO_VFUNCS(uncore, gen11_fwtable);
  	} else if (GRAPHICS_VER(i915) >= 12) {
  		ASSIGN_FW_DOMAINS_TABLE(uncore, __gen12_fw_ranges);
+		ASSIGN_SHADOW_TABLE(uncore, gen12_shadowed_regs);
  		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen12_fwtable);
  		ASSIGN_READ_MMIO_VFUNCS(uncore, gen11_fwtable);
  	} else if (GRAPHICS_VER(i915) == 11) {
  		ASSIGN_FW_DOMAINS_TABLE(uncore, __gen11_fw_ranges);
+		ASSIGN_SHADOW_TABLE(uncore, gen11_shadowed_regs);
  		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen11_fwtable);
  		ASSIGN_READ_MMIO_VFUNCS(uncore, gen11_fwtable);
  	} else if (IS_GRAPHICS_VER(i915, 9, 10)) {
  		ASSIGN_FW_DOMAINS_TABLE(uncore, __gen9_fw_ranges);
+		ASSIGN_SHADOW_TABLE(uncore, gen8_shadowed_regs);
  		ASSIGN_WRITE_MMIO_VFUNCS(uncore, fwtable);
  		ASSIGN_READ_MMIO_VFUNCS(uncore, fwtable);
  	} else if (IS_CHERRYVIEW(i915)) {
  		ASSIGN_FW_DOMAINS_TABLE(uncore, __chv_fw_ranges);
+		ASSIGN_SHADOW_TABLE(uncore, gen8_shadowed_regs);
  		ASSIGN_WRITE_MMIO_VFUNCS(uncore, fwtable);
  		ASSIGN_READ_MMIO_VFUNCS(uncore, fwtable);
  	} else if (GRAPHICS_VER(i915) == 8) {
  		ASSIGN_FW_DOMAINS_TABLE(uncore, __gen6_fw_ranges);
+		ASSIGN_SHADOW_TABLE(uncore, gen8_shadowed_regs);
  		ASSIGN_WRITE_MMIO_VFUNCS(uncore, gen8);
  		ASSIGN_READ_MMIO_VFUNCS(uncore, fwtable);

Note for later - I think by the end of the series all "assign read" in 
this block become fwtable so you could consolidate them if wanted.

  	} else if (IS_VALLEYVIEW(i915)) {
diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h
index 531665b08039..2f31c50eeae2 100644
--- a/drivers/gpu/drm/i915/intel_uncore.h
+++ b/drivers/gpu/drm/i915/intel_uncore.h
@@ -142,6 +142,13 @@ struct intel_uncore {
  	const struct intel_forcewake_range *fw_domains_table;
  	unsigned int fw_domains_table_entries;
  
+	/*
+	 * Shadowed registers are special cases where we can safely write
+	 * to the register *without* grabbing forcewake.
+	 */
+	const struct i915_range *shadowed_reg_table;
+	unsigned int shadowed_reg_table_entries;
+
  	struct notifier_block pmic_bus_access_nb;
  	struct intel_uncore_funcs funcs;
  


Looks fine and all tidies are optional.

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>

Regards,

Tvrtko






