[Intel-gfx] [PATCH 17/28] drm/i915: Ensure gem_contexts selftests work with unbind changes.

Maarten Lankhorst
2021-10-21T10:37:12Z

In the next commit, we don't evict when refcount = 0.

igt_vm_isolation() continuously tries to pin/unpin at same address,
but also calls put() on the object, which means the object may not
be unpinned in time.

Instead of this, re-use the same object over and over, so they can
be unbound as required.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
.../drm/i915/gem/selftests/i915_gem_context.c | 54 +++++++++++--------
1 file changed, 32 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index b32f7fed2d9c..3fc595b57cf4 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -1481,10 +1481,10 @@ static int check_scratch(struct i915_address_space *vm, u64 offset)

static int write_to_scratch(struct i915_gem_context *ctx,
struct intel_engine_cs *engine,
+ struct drm_i915_gem_object *obj,
u64 offset, u32 value)
{
struct drm_i915_private *i915 = ctx->i915;
- struct drm_i915_gem_object *obj;
struct i915_address_space *vm;
struct i915_request *rq;
struct i915_vma *vma;
@@ -1497,15 +1497,9 @@ static int write_to_scratch(struct i915_gem_context *ctx,
if (err)
return err;

- obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
- if (IS_ERR(obj))
- return PTR_ERR(obj);
-
cmd = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
- if (IS_ERR(cmd)) {
- err = PTR_ERR(cmd);
- goto out;
- }
+ if (IS_ERR(cmd))
+ return PTR_ERR(cmd);

*cmd++ = MI_STORE_DWORD_IMM_GEN4;
if (GRAPHICS_VER(i915) >= 8) {
@@ -1569,17 +1563,19 @@ static int write_to_scratch(struct i915_gem_context *ctx,
i915_vma_unpin(vma);
out_vm:
i915_vm_put(vm);
-out:
- i915_gem_object_put(obj);
+
+ if (!err)
+ err = i915_gem_object_wait(obj, 0, MAX_SCHEDULE_TIMEOUT);
+
return err;
}

static int read_from_scratch(struct i915_gem_context *ctx,
struct intel_engine_cs *engine,
+ struct drm_i915_gem_object *obj,
u64 offset, u32 *value)
{
struct drm_i915_private *i915 = ctx->i915;
- struct drm_i915_gem_object *obj;
struct i915_address_space *vm;
const u32 result = 0x100;
struct i915_request *rq;
@@ -1594,10 +1590,6 @@ static int read_from_scratch(struct i915_gem_context *ctx,
if (err)
return err;

- obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
- if (IS_ERR(obj))
- return PTR_ERR(obj);
-
if (GRAPHICS_VER(i915) >= 8) {
const u32 GPR0 = engine->mmio_base + 0x600;

@@ -1615,7 +1607,7 @@ static int read_from_scratch(struct i915_gem_context *ctx,
cmd = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
if (IS_ERR(cmd)) {
err = PTR_ERR(cmd);
- goto out;
+ goto err_unpin;
}

memset(cmd, POISON_INUSE, PAGE_SIZE);
@@ -1651,7 +1643,7 @@ static int read_from_scratch(struct i915_gem_context *ctx,
cmd = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
if (IS_ERR(cmd)) {
err = PTR_ERR(cmd);
- goto out;
+ goto err_unpin;
}

memset(cmd, POISON_INUSE, PAGE_SIZE);
@@ -1722,8 +1714,10 @@ static int read_from_scratch(struct i915_gem_context *ctx,
i915_vma_unpin(vma);
out_vm:
i915_vm_put(vm);
-out:
- i915_gem_object_put(obj);
+
+ if (!err)
+ err = i915_gem_object_wait(obj, 0, MAX_SCHEDULE_TIMEOUT);
+
return err;
}

@@ -1765,6 +1759,7 @@ static int igt_vm_isolation(void *arg)
u64 vm_total;
u32 expected;
int err;
+ struct drm_i915_gem_object *obj_a, *obj_b;

if (GRAPHICS_VER(i915) < 7)
return 0;
@@ -1810,6 +1805,18 @@ static int igt_vm_isolation(void *arg)
vm_total = ctx_a->vm->total;
GEM_BUG_ON(ctx_b->vm->total != vm_total);

+ obj_a = i915_gem_object_create_internal(i915, PAGE_SIZE);
+ if (IS_ERR(obj_a)) {
+ err = PTR_ERR(obj_a);
+ goto out_file;
+ }
+
+ obj_b = i915_gem_object_create_internal(i915, PAGE_SIZE);
+ if (IS_ERR(obj_b)) {
+ err = PTR_ERR(obj_b);
+ goto put_a;
+ }
+
count = 0;
num_engines = 0;
for_each_uabi_engine(engine, i915) {
@@ -1832,10 +1839,10 @@ static int igt_vm_isolation(void *arg)
I915_GTT_PAGE_SIZE, vm_total,
sizeof(u32), alignof_dword);

- err = write_to_scratch(ctx_a, engine,
+ err = write_to_scratch(ctx_a, engine, obj_a,
offset, 0xdeadbeef);
if (err == 0)
- err = read_from_scratch(ctx_b, engine,
+ err = read_from_scratch(ctx_b, engine, obj_b,
offset, &value);
if (err)
goto out_file;
@@ -1858,6 +1865,9 @@ static int igt_vm_isolation(void *arg)
pr_info("Checked %lu scratch offsets across %lu engines\n",
count, num_engines);

+ i915_gem_object_put(obj_b);
+put_a:
+ i915_gem_object_put(obj_a);
out_file:
if (igt_live_test_end(&t))
err = -EIO;
--
2.33.0