[Intel-gfx] [PATCH 19/61] drm/i915: Handle ww locking in init_status_page

Maarten Lankhorst
2020-10-02T13:00:31Z

Try to pin to ggtt first, and use a full ww loop to handle
eviction correctly.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
---
drivers/gpu/drm/i915/gt/intel_engine_cs.c | 37 +++++++++++++++--------
1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 1985772152bf..66d87ce764e0 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -615,6 +615,7 @@ static void cleanup_status_page(struct intel_engine_cs *engine)
}

static int pin_ggtt_status_page(struct intel_engine_cs *engine,
+ struct i915_gem_ww_ctx *ww,
struct i915_vma *vma)
{
unsigned int flags;
@@ -635,12 +636,13 @@ static int pin_ggtt_status_page(struct intel_engine_cs *engine,
else
flags = PIN_HIGH;

- return i915_ggtt_pin(vma, NULL, 0, flags);
+ return i915_ggtt_pin(vma, ww, 0, flags);
}

static int init_status_page(struct intel_engine_cs *engine)
{
struct drm_i915_gem_object *obj;
+ struct i915_gem_ww_ctx ww;
struct i915_vma *vma;
void *vaddr;
int ret;
@@ -664,30 +666,39 @@ static int init_status_page(struct intel_engine_cs *engine)
vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
- goto err;
+ goto err_put;
}

+ i915_gem_ww_ctx_init(&ww, true);
+retry:
+ ret = i915_gem_object_lock(obj, &ww);
+ if (!ret && !HWS_NEEDS_PHYSICAL(engine->i915))
+ ret = pin_ggtt_status_page(engine, &ww, vma);
+ if (ret)
+ goto err;
+
vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
if (IS_ERR(vaddr)) {
ret = PTR_ERR(vaddr);
- goto err;
+ goto err_unpin;
}

engine->status_page.addr = memset(vaddr, 0, PAGE_SIZE);
engine->status_page.vma = vma;

- if (!HWS_NEEDS_PHYSICAL(engine->i915)) {
- ret = pin_ggtt_status_page(engine, vma);
- if (ret)
- goto err_unpin;
- }
-
- return 0;
-
err_unpin:
- i915_gem_object_unpin_map(obj);
+ if (ret)
+ i915_vma_unpin(vma);
err:
- i915_gem_object_put(obj);
+ if (ret == -EDEADLK) {
+ ret = i915_gem_ww_ctx_backoff(&ww);
+ if (!ret)
+ goto retry;
+ }
+ i915_gem_ww_ctx_fini(&ww);
+err_put:
+ if (ret)
+ i915_gem_object_put(obj);
return ret;