diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-02-10 23:57:20 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-02-11 20:42:17 +0300 |
| commit | f16ccb6445d3c2038998375a8491686c43e6026e (patch) | |
| tree | 8e45527a62aeffef39696561f6baea39c503d096 /drivers/gpu/drm/i915/i915_request.c | |
| parent | 6313e78e720f82ab135f8cce809e0259ab54f7f3 (diff) | |
| download | linux-f16ccb6445d3c2038998375a8491686c43e6026e.tar.xz | |
drm/i915: Disable use of hwsp_cacheline for kernel_context
Currently on execlists, we use a local hwsp for the kernel_context,
rather than the engine's HWSP, as this is the default for execlists.
However, seqno wrap requires allocating a new HWSP cacheline, and may
require pinning a new HWSP page in the GGTT. This operation requiring
pinning in the GGTT is not allowed within the kernel_context timeline,
as doing so may require re-entering the kernel_context in order to evict
from the GGTT. As we want to avoid requiring a new HWSP for the
kernel_context, we can use the permanently pinned engine's HWSP instead.
However to do so we must prevent the use of semaphores reading the
kernel_context's HWSP, as the use of semaphores do not support rollover
onto the same cacheline. Fortunately, the kernel_context is mostly
isolated, so unlikely to give benefit to semaphores.
Reported-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200210205722.794180-5-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_request.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_request.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 0ecc2cf64216..1adb8cf35f75 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -886,6 +886,12 @@ emit_semaphore_wait(struct i915_request *to, struct i915_request *from, gfp_t gfp) { + if (!intel_context_use_semaphores(to->context)) + goto await_fence; + + if (!rcu_access_pointer(from->hwsp_cacheline)) + goto await_fence; + /* Just emit the first semaphore we see as request space is limited. */ if (already_busywaiting(to) & from->engine->mask) goto await_fence; @@ -931,12 +937,8 @@ i915_request_await_request(struct i915_request *to, struct i915_request *from) ret = i915_sw_fence_await_sw_fence_gfp(&to->submit, &from->submit, I915_FENCE_GFP); - else if (intel_context_use_semaphores(to->context)) - ret = emit_semaphore_wait(to, from, I915_FENCE_GFP); else - ret = i915_sw_fence_await_dma_fence(&to->submit, - &from->fence, 0, - I915_FENCE_GFP); + ret = emit_semaphore_wait(to, from, I915_FENCE_GFP); if (ret < 0) return ret; @@ -1035,6 +1037,8 @@ __i915_request_await_execution(struct i915_request *to, { int err; + GEM_BUG_ON(intel_context_is_barrier(from->context)); + /* Submit both requests at the same time */ err = __await_execution(to, from, hook, I915_FENCE_GFP); if (err) |