Protect the access to driver and timeline name which otherwise could be
freed as dma-fence exported is signalling fences.
Now that the safe access is handled in the dma-fence API, the external
callers such as sync_file, and our internal code paths, we can drop the
similar protection from i915_fence_get_timeline_name().
Signed-off-by: Tvrtko Ursulin <tvrtko.ursu...@igalia.com>
---
drivers/gpu/drm/i915/gt/intel_gt_requests.c | 2 ++
drivers/gpu/drm/i915/i915_request.c | 17 +++--------------
drivers/gpu/drm/i915/i915_sw_fence.c | 2 ++
3 files changed, 7 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
index ae3557ed6c1e..11fca24c8b5b 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
@@ -251,10 +251,12 @@ void intel_gt_watchdog_work(struct work_struct *work)
if (!i915_request_completed(rq)) {
struct dma_fence *f = &rq->fence;
+ dma_fence_access_begin();
pr_notice("Fence expiration time out
i915-%s:%s:%llx!\n",
dma_fence_driver_name(f),
dma_fence_timeline_name(f),
f->seqno);
+ dma_fence_access_end();
i915_request_cancel(rq, -EINTR);
}
i915_request_put(rq);
diff --git a/drivers/gpu/drm/i915/i915_request.c
b/drivers/gpu/drm/i915/i915_request.c
index 4874c4f1e4ab..a8de736ff556 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -66,18 +66,6 @@ static const char *i915_fence_get_timeline_name(struct
dma_fence *fence)
{
const struct i915_gem_context *ctx;
- /*
- * The timeline struct (as part of the ppgtt underneath a context)
- * may be freed when the request is no longer in use by the GPU.
- * We could extend the life of a context to beyond that of all
- * fences, possibly keeping the hw resource around indefinitely,
- * or we just give them a false name. Since
- * dma_fence_ops.get_timeline_name is a debug feature, the occasional
- * lie seems justifiable.
- */
- if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
- return "signaled";
-
ctx = i915_request_gem_context(to_request(fence));
if (!ctx)
return "[" DRIVER_NAME "]";
@@ -2184,7 +2172,6 @@ void i915_request_show(struct drm_printer *m,
const char *prefix,
int indent)
{
- const char *name = dma_fence_timeline_name((struct dma_fence
*)&rq->fence);
char buf[80] = "";
int x = 0;
@@ -2220,6 +2207,7 @@ void i915_request_show(struct drm_printer *m,
x = print_sched_attr(&rq->sched.attr, buf, x, sizeof(buf));
+ dma_fence_access_begin();
drm_printf(m, "%s%.*s%c %llx:%lld%s%s %s @ %dms: %s\n",
prefix, indent, " ",
queue_status(rq),
@@ -2228,7 +2216,8 @@ void i915_request_show(struct drm_printer *m,
fence_status(rq),
buf,
jiffies_to_msecs(jiffies - rq->emitted_jiffies),
- name);
+ dma_fence_timeline_name((struct dma_fence *)&rq->fence));
+ dma_fence_access_end();
}
static bool engine_match_ring(struct intel_engine_cs *engine, struct
i915_request *rq)
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c
b/drivers/gpu/drm/i915/i915_sw_fence.c
index e51ca7e50a4e..e7bdc1165b90 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/i915_sw_fence.c
@@ -434,11 +434,13 @@ static void timer_i915_sw_fence_wake(struct timer_list *t)
if (!fence)
return;
+ dma_fence_access_begin();
pr_notice("Asynchronous wait on fence %s:%s:%llx timed out
(hint:%ps)\n",
dma_fence_driver_name(cb->dma),
dma_fence_timeline_name(cb->dma),
cb->dma->seqno,
i915_sw_fence_debug_hint(fence));
+ dma_fence_access_end();
i915_sw_fence_set_error_once(fence, -ETIMEDOUT);
i915_sw_fence_complete(fence);
--
2.48.0
