[PATCH 1/2] drm/i915: Add test for invalid flag bits in whitelist entries

John.C.Harrison
2019-07-03T02:06:05Z

From: John Harrison <John.C.Harrison@Intel.com>

As per review feedback by Tvrtko, added a check that no invalid bits
are being set in the whitelist flags fields.

Also updated the read/write access definitions to make it clearer that
they are an enum field not a set of single bit flags.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
CC: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
drivers/gpu/drm/i915/gt/intel_workarounds.c | 29 +++++++++++++++----
.../gpu/drm/i915/gt/selftest_workarounds.c | 14 ++++++---
drivers/gpu/drm/i915/i915_reg.h | 12 ++++++--
3 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index a908d829d6bd..9b401833aceb 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -1011,6 +1011,20 @@ bool intel_gt_verify_workarounds(struct intel_gt *gt, const char *from)
return wa_list_verify(gt->uncore, &gt->i915->gt_wa_list, from);
}

+static inline bool is_nonpriv_flags_valid(u32 flags)
+{
+ /* Check only valid flag bits are set */
+ if (flags & ~RING_FORCE_TO_NONPRIV_MASK_VALID)
+ return false;
+
+ /* NB: Only 3 out of 4 enum values are valid for access field */
+ if ((flags & RING_FORCE_TO_NONPRIV_ACCESS_MASK) ==
+ RING_FORCE_TO_NONPRIV_ACCESS_INVALID)
+ return false;
+
+ return true;
+}
+
static void
whitelist_reg_ext(struct i915_wa_list *wal, i915_reg_t reg, u32 flags)
{
@@ -1021,6 +1035,9 @@ whitelist_reg_ext(struct i915_wa_list *wal, i915_reg_t reg, u32 flags)
if (GEM_DEBUG_WARN_ON(wal->count >= RING_MAX_NONPRIV_SLOTS))
return;

+ if (GEM_DEBUG_WARN_ON(!is_nonpriv_flags_valid(flags)))
+ return;
+
wa.reg.reg |= flags;
_wa_add(wal, &wa);
}
@@ -1028,7 +1045,7 @@ whitelist_reg_ext(struct i915_wa_list *wal, i915_reg_t reg, u32 flags)
static void
whitelist_reg(struct i915_wa_list *wal, i915_reg_t reg)
{
- whitelist_reg_ext(wal, reg, RING_FORCE_TO_NONPRIV_RW);
+ whitelist_reg_ext(wal, reg, RING_FORCE_TO_NONPRIV_ACCESS_RW);
}

static void gen9_whitelist_build(struct i915_wa_list *w)
@@ -1109,7 +1126,7 @@ static void cfl_whitelist_build(struct intel_engine_cs *engine)
* - PS_DEPTH_COUNT_UDW
*/
whitelist_reg_ext(w, PS_INVOCATION_COUNT,
- RING_FORCE_TO_NONPRIV_RD |
+ RING_FORCE_TO_NONPRIV_ACCESS_RD |
RING_FORCE_TO_NONPRIV_RANGE_4);
}

@@ -1149,20 +1166,20 @@ static void icl_whitelist_build(struct intel_engine_cs *engine)
* - PS_DEPTH_COUNT_UDW
*/
whitelist_reg_ext(w, PS_INVOCATION_COUNT,
- RING_FORCE_TO_NONPRIV_RD |
+ RING_FORCE_TO_NONPRIV_ACCESS_RD |
RING_FORCE_TO_NONPRIV_RANGE_4);
break;

case VIDEO_DECODE_CLASS:
/* hucStatusRegOffset */
whitelist_reg_ext(w, _MMIO(0x2000 + engine->mmio_base),
- RING_FORCE_TO_NONPRIV_RD);
+ RING_FORCE_TO_NONPRIV_ACCESS_RD);
/* hucUKernelHdrInfoRegOffset */
whitelist_reg_ext(w, _MMIO(0x2014 + engine->mmio_base),
- RING_FORCE_TO_NONPRIV_RD);
+ RING_FORCE_TO_NONPRIV_ACCESS_RD);
/* hucStatus2RegOffset */
whitelist_reg_ext(w, _MMIO(0x23B0 + engine->mmio_base),
- RING_FORCE_TO_NONPRIV_RD);
+ RING_FORCE_TO_NONPRIV_ACCESS_RD);
break;

default:
diff --git a/drivers/gpu/drm/i915/gt/selftest_workarounds.c b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
index b933d831eeb1..f8151d5946c8 100644
--- a/drivers/gpu/drm/i915/gt/selftest_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
@@ -394,6 +394,10 @@ static bool wo_register(struct intel_engine_cs *engine, u32 reg)
enum intel_platform platform = INTEL_INFO(engine->i915)->platform;
int i;

+ if ((reg & RING_FORCE_TO_NONPRIV_ACCESS_MASK) ==
+ RING_FORCE_TO_NONPRIV_ACCESS_WR)
+ return true;
+
for (i = 0; i < ARRAY_SIZE(wo_registers); i++) {
if (wo_registers[i].platform == platform &&
wo_registers[i].reg == reg)
@@ -405,7 +409,8 @@ static bool wo_register(struct intel_engine_cs *engine, u32 reg)

static bool ro_register(u32 reg)
{
- if (reg & RING_FORCE_TO_NONPRIV_RD)
+ if ((reg & RING_FORCE_TO_NONPRIV_ACCESS_MASK) ==
+ RING_FORCE_TO_NONPRIV_ACCESS_RD)
return true;

return false;
@@ -757,8 +762,8 @@ static int read_whitelisted_registers(struct i915_gem_context *ctx,
u64 offset = results->node.start + sizeof(u32) * i;
u32 reg = i915_mmio_reg_offset(engine->whitelist.list[i].reg);

- /* Clear RD only and WR only flags */
- reg &= ~(RING_FORCE_TO_NONPRIV_RD | RING_FORCE_TO_NONPRIV_WR);
+ /* Clear access permission field */
+ reg &= ~RING_FORCE_TO_NONPRIV_ACCESS_MASK;

*cs++ = srm;
*cs++ = reg;
@@ -928,7 +933,8 @@ check_whitelisted_registers(struct intel_engine_cs *engine,
for (i = 0; i < engine->whitelist.count; i++) {
const struct i915_wa *wa = &engine->whitelist.list[i];

- if (i915_mmio_reg_offset(wa->reg) & RING_FORCE_TO_NONPRIV_RD)
+ if (i915_mmio_reg_offset(wa->reg) &
+ RING_FORCE_TO_NONPRIV_ACCESS_RD)
continue;

if (!fn(engine, a[i], b[i], wa->reg))
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c814cc1b3ae5..0bd4bf0b4629 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2521,13 +2521,19 @@ enum i915_power_well_id {
#define RING_WAIT_SEMAPHORE (1 << 10) /* gen6+ */

#define RING_FORCE_TO_NONPRIV(base, i) _MMIO(((base) + 0x4D0) + (i) * 4)
-#define RING_FORCE_TO_NONPRIV_RW (0 << 28) /* CFL+ & Gen11+ */
-#define RING_FORCE_TO_NONPRIV_RD (1 << 28)
-#define RING_FORCE_TO_NONPRIV_WR (2 << 28)
+#define RING_FORCE_TO_NONPRIV_ACCESS_RW (0 << 28) /* CFL+ & Gen11+ */
+#define RING_FORCE_TO_NONPRIV_ACCESS_RD (1 << 28)
+#define RING_FORCE_TO_NONPRIV_ACCESS_WR (2 << 28)
+#define RING_FORCE_TO_NONPRIV_ACCESS_INVALID (3 << 28)
+#define RING_FORCE_TO_NONPRIV_ACCESS_MASK (3 << 28)
#define RING_FORCE_TO_NONPRIV_RANGE_1 (0 << 0) /* CFL+ & Gen11+ */
#define RING_FORCE_TO_NONPRIV_RANGE_4 (1 << 0)
#define RING_FORCE_TO_NONPRIV_RANGE_16 (2 << 0)
#define RING_FORCE_TO_NONPRIV_RANGE_64 (3 << 0)
+#define RING_FORCE_TO_NONPRIV_RANGE_MASK (3 << 0)
+#define RING_FORCE_TO_NONPRIV_MASK_VALID \
+ (RING_FORCE_TO_NONPRIV_RANGE_MASK \
+ | RING_FORCE_TO_NONPRIV_ACCESS_MASK)
#define RING_MAX_NONPRIV_SLOTS 12

#define GEN7_TLB_RD_ADDR _MMIO(0x4700)
--
2.21.0.5.gaeb582a983