[PATCH 2/2] drm/i915: Implement read-only support in whitelist selftest

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

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.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
CC: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
.../gpu/drm/i915/gt/selftest_workarounds.c | 43 +++++++++++++------
1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/selftest_workarounds.c b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
index f8151d5946c8..5cd2b17105ba 100644
--- a/drivers/gpu/drm/i915/gt/selftest_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
@@ -482,12 +482,12 @@ 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 +588,37 @@ 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 {
+ /* detect write masking */
+ rsvd = results[ARRAY_SIZE(values)];
+ 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 +635,10 @@ 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 +646,10 @@ 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++;
--
2.21.0.5.gaeb582a983