[PATCH] drm/i915: Implement read-only support in whitelist selftest

John.C.Harrison
2019-06-18T19:54:22Z

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

Newer hardware supports extra feature in the whitelist registers. This
patch updates the selftest to test that entries marked as read only
are actually read only.

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 | 8 +--
.../gpu/drm/i915/gt/selftest_workarounds.c | 53 +++++++++++++------
drivers/gpu/drm/i915/i915_reg.h | 9 ++--
3 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 93caa7b6d7a9..4429ee08b20e 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -1028,7 +1028,7 @@ 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)
@@ -1134,13 +1134,13 @@ printk(KERN_INFO "%-32s:%4d> Boo! [engine = %s, instance = %d, base = 0x%X, reg

/* 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 eb6d3aa2c8cc..a0a88ec66861 100644
--- a/drivers/gpu/drm/i915/gt/selftest_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
@@ -399,6 +399,10 @@ 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)
@@ -410,7 +414,8 @@ 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;
@@ -482,12 +487,12 @@ static int check_dirty_whitelist(struct i915_gem_context *ctx,
u32 srm, lrm, rsvd;
u32 expect;
int idx;
+ bool ro_reg;

if (wo_register(engine, reg))
continue;

- if (ro_register(reg))
- continue;
+ ro_reg = ro_register(reg);

srm = MI_STORE_REGISTER_MEM;
lrm = MI_LOAD_REGISTER_MEM;
@@ -588,24 +593,36 @@ static int check_dirty_whitelist(struct i915_gem_context *ctx,
}

GEM_BUG_ON(values[ARRAY_SIZE(values) - 1] != 0xffffffff);
- rsvd = results[ARRAY_SIZE(values)]; /* detect write masking */
- if (!rsvd) {
- pr_err("%s: Unable to write to whitelisted register %x\n",
- engine->name, reg);
- err = -EINVAL;
- goto out_unpin;
+ if (ro_reg) {
+ rsvd = 0xFFFFFFFF;
+ } else {
+ rsvd = results[ARRAY_SIZE(values)]; /* detect write masking */
+ if (!rsvd) {
+ pr_err("%s: Unable to write to whitelisted register %x\n",
+ engine->name, reg);
+ err = -EINVAL;
+ goto out_unpin;
+ }
}

expect = results[0];
idx = 1;
for (v = 0; v < ARRAY_SIZE(values); v++) {
- expect = reg_write(expect, values[v], rsvd);
+ if (ro_reg)
+ expect = results[0];
+ else
+ expect = reg_write(expect, values[v], rsvd);
+
if (results[idx] != expect)
err++;
idx++;
}
for (v = 0; v < ARRAY_SIZE(values); v++) {
- expect = reg_write(expect, ~values[v], rsvd);
+ if (ro_reg)
+ expect = results[0];
+ else
+ expect = reg_write(expect, ~values[v], rsvd);
+
if (results[idx] != expect)
err++;
idx++;
@@ -622,7 +639,10 @@ static int check_dirty_whitelist(struct i915_gem_context *ctx,
for (v = 0; v < ARRAY_SIZE(values); v++) {
u32 w = values[v];

- expect = reg_write(expect, w, rsvd);
+ if (ro_reg)
+ expect = results[0];
+ else
+ expect = reg_write(expect, w, rsvd);
pr_info("Wrote %08x, read %08x, expect %08x\n",
w, results[idx], expect);
idx++;
@@ -630,7 +650,10 @@ static int check_dirty_whitelist(struct i915_gem_context *ctx,
for (v = 0; v < ARRAY_SIZE(values); v++) {
u32 w = ~values[v];

- expect = reg_write(expect, w, rsvd);
+ if (ro_reg)
+ expect = results[0];
+ else
+ expect = reg_write(expect, w, rsvd);
pr_info("Wrote %08x, read %08x, expect %08x\n",
w, results[idx], expect);
idx++;
@@ -762,8 +785,8 @@ 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;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index cc295a4f6e92..ba22e3b8f77e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2513,13 +2513,16 @@ 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_MAX_NONPRIV_SLOTS 12

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