[Intel-gfx] [PATCH 3/3] drm/i915: Check that we do find forcewake domain on gen11+

[Mika Kuoppala]

By always requiring a valid forcewake domain, even
FORCEWAKE_NONE, we can make assertions that accesses
need to land on a valid domain and not go out of bounds.

Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 46 +++++++++++++++++++++++------
 drivers/gpu/drm/i915/intel_uncore.h |  4 ++-
 2 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 94a97bf8c021..8e12b5334018 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -845,7 +845,7 @@ static int fw_range_cmp(u32 offset, const struct intel_forcewake_range *entry)
 })
 
 static enum forcewake_domains
-find_fw_domain(struct intel_uncore *uncore, u32 offset)
+__find_fw_domain(struct intel_uncore *uncore, u32 offset)
 {
 	const struct intel_forcewake_range *entry;
 
@@ -855,7 +855,7 @@ find_fw_domain(struct intel_uncore *uncore, u32 offset)
 			fw_range_cmp);
 
 	if (!entry)
-		return 0;
+		return FORCEWAKE_INVALID;
 
 	/*
 	 * The list of FW domains depends on the SKU in gen11+ so we
@@ -872,6 +872,34 @@ find_fw_domain(struct intel_uncore *uncore, u32 offset)
 	return entry->domains;
 }
 
+static enum forcewake_domains
+find_fw_domain(struct intel_uncore *uncore, u32 offset)
+{
+	enum forcewake_domains fw_domains;
+
+	fw_domains = __find_fw_domain(uncore, offset);
+
+	if (fw_domains == FORCEWAKE_INVALID)
+		return FORCEWAKE_NONE;
+	else
+		return fw_domains;
+}
+
+static enum forcewake_domains
+find_fw_domain_check(struct intel_uncore *uncore, u32 offset)
+{
+	enum forcewake_domains fw_domains;
+
+	fw_domains = __find_fw_domain(uncore, offset);
+
+	if (WARN(fw_domains == FORCEWAKE_INVALID,
+		 "Unknown forcewake domain(s) accessed at 0x%x\n",
+		 offset))
+		return FORCEWAKE_ALL;
+
+	return fw_domains;
+}
+
 #define GEN_FW_RANGE(s, e, d) \
 	{ .start = (s), .end = (e), .domains = (d) }
 
@@ -900,10 +928,10 @@ static const struct intel_forcewake_range __vlv_fw_ranges[] = {
 })
 
 #define __gen11_fwtable_reg_read_fw_domains(uncore, offset) \
-	find_fw_domain(uncore, offset)
+	find_fw_domain_check(uncore, offset)
 
 #define __gen12_fwtable_reg_read_fw_domains(uncore, offset) \
-	find_fw_domain(uncore, offset)
+	find_fw_domain_check(uncore, offset)
 
 /* *Must* be sorted by offset! See intel_shadow_table_check(). */
 static const i915_reg_t gen8_shadowed_regs[] = {
@@ -1033,7 +1061,7 @@ static const struct intel_forcewake_range __chv_fw_ranges[] = {
 /* *Must* be sorted by offset ranges! See intel_fw_table_check(). */
 static const struct intel_forcewake_range __gen9_fw_ranges[] = {
 	GEN_FW_RANGE(0x0, 0xaff, FORCEWAKE_BLITTER),
-	GEN_FW_RANGE(0xb00, 0x1fff, 0), /* uncore range */
+	GEN_FW_RANGE(0xb00, 0x1fff, FORCEWAKE_NONE), /* uncore range */
 	GEN_FW_RANGE(0x2000, 0x26ff, FORCEWAKE_RENDER),
 	GEN_FW_RANGE(0x2700, 0x2fff, FORCEWAKE_BLITTER),
 	GEN_FW_RANGE(0x3000, 0x3fff, FORCEWAKE_RENDER),
@@ -1069,7 +1097,7 @@ static const struct intel_forcewake_range __gen9_fw_ranges[] = {
 /* *Must* be sorted by offset ranges! See intel_fw_table_check(). */
 static const struct intel_forcewake_range __gen11_fw_ranges[] = {
 	GEN_FW_RANGE(0x0, 0xaff, FORCEWAKE_BLITTER),
-	GEN_FW_RANGE(0xb00, 0x1fff, 0), /* uncore range */
+	GEN_FW_RANGE(0xb00, 0x1fff, FORCEWAKE_NONE), /* uncore range */
 	GEN_FW_RANGE(0x2000, 0x26ff, FORCEWAKE_RENDER),
 	GEN_FW_RANGE(0x2700, 0x2fff, FORCEWAKE_BLITTER),
 	GEN_FW_RANGE(0x3000, 0x3fff, FORCEWAKE_RENDER),
@@ -1092,7 +1120,7 @@ static const struct intel_forcewake_range __gen11_fw_ranges[] = {
 	GEN_FW_RANGE(0x1a000, 0x243ff, FORCEWAKE_BLITTER),
 	GEN_FW_RANGE(0x24400, 0x247ff, FORCEWAKE_RENDER),
 	GEN_FW_RANGE(0x24800, 0x3ffff, FORCEWAKE_BLITTER),
-	GEN_FW_RANGE(0x40000, 0x1bffff, 0),
+	GEN_FW_RANGE(0x40000, 0x1bffff, FORCEWAKE_NONE),
 	GEN_FW_RANGE(0x1c0000, 0x1c3fff, FORCEWAKE_MEDIA_VDBOX0),
 	GEN_FW_RANGE(0x1c4000, 0x1c7fff, FORCEWAKE_MEDIA_VDBOX1),
 	GEN_FW_RANGE(0x1c8000, 0x1cbfff, FORCEWAKE_MEDIA_VEBOX0),
@@ -1105,7 +1133,7 @@ static const struct intel_forcewake_range __gen11_fw_ranges[] = {
 /* *Must* be sorted by offset ranges! See intel_fw_table_check(). */
 static const struct intel_forcewake_range __gen12_fw_ranges[] = {
 	GEN_FW_RANGE(0x0, 0xaff, FORCEWAKE_BLITTER),
-	GEN_FW_RANGE(0xb00, 0x1fff, 0), /* uncore range */
+	GEN_FW_RANGE(0xb00, 0x1fff, FORCEWAKE_NONE), /* uncore range */
 	GEN_FW_RANGE(0x2000, 0x26ff, FORCEWAKE_RENDER),
 	GEN_FW_RANGE(0x2700, 0x2fff, FORCEWAKE_BLITTER),
 	GEN_FW_RANGE(0x3000, 0x3fff, FORCEWAKE_RENDER),
@@ -1132,7 +1160,7 @@ static const struct intel_forcewake_range __gen12_fw_ranges[] = {
 	GEN_FW_RANGE(0x1c000, 0x243ff, FORCEWAKE_BLITTER),
 	GEN_FW_RANGE(0x24400, 0x247ff, FORCEWAKE_RENDER),
 	GEN_FW_RANGE(0x24800, 0x3ffff, FORCEWAKE_BLITTER),
-	GEN_FW_RANGE(0x40000, 0x1bffff, 0),
+	GEN_FW_RANGE(0x40000, 0x1bffff, FORCEWAKE_NONE),
 	GEN_FW_RANGE(0x1c0000, 0x1c3fff, FORCEWAKE_MEDIA_VDBOX0),
 	GEN_FW_RANGE(0x1c4000, 0x1c7fff, FORCEWAKE_MEDIA_VDBOX1),
 	GEN_FW_RANGE(0x1c8000, 0x1cbfff, FORCEWAKE_MEDIA_VEBOX0),
diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h
index 414fc2cb0459..7d271aaf8f1b 100644
--- a/drivers/gpu/drm/i915/intel_uncore.h
+++ b/drivers/gpu/drm/i915/intel_uncore.h
@@ -58,6 +58,7 @@ enum forcewake_domain_id {
 };
 
 enum forcewake_domains {
+	FORCEWAKE_NONE		= 0,
 	FORCEWAKE_RENDER	= BIT(FW_DOMAIN_ID_RENDER),
 	FORCEWAKE_BLITTER	= BIT(FW_DOMAIN_ID_BLITTER),
 	FORCEWAKE_MEDIA		= BIT(FW_DOMAIN_ID_MEDIA),
@@ -68,7 +69,8 @@ enum forcewake_domains {
 	FORCEWAKE_MEDIA_VEBOX0	= BIT(FW_DOMAIN_ID_MEDIA_VEBOX0),
 	FORCEWAKE_MEDIA_VEBOX1	= BIT(FW_DOMAIN_ID_MEDIA_VEBOX1),
 
-	FORCEWAKE_ALL = BIT(FW_DOMAIN_ID_COUNT) - 1
+	FORCEWAKE_ALL = BIT(FW_DOMAIN_ID_COUNT) - 1,
+	FORCEWAKE_INVALID = BIT(FW_DOMAIN_ID_COUNT),
 };
 
 struct intel_uncore_funcs {
-- 
2.17.1