--- /dev/null
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2014-2016 Intel Corporation
+ */
+
+#include "gt/intel_engine.h"
+
+#include "i915_gem_ioctls.h"
+#include "i915_gem_object.h"
+
+static __always_inline u32 __busy_read_flag(u8 id)
+{
+ if (id == (u8)I915_ENGINE_CLASS_INVALID)
+ return 0xffff0000u;
+
+ GEM_BUG_ON(id >= 16);
+ return 0x10000u << id;
+}
+
+static __always_inline u32 __busy_write_id(u8 id)
+{
+ /*
+ * The uABI guarantees an active writer is also amongst the read
+ * engines. This would be true if we accessed the activity tracking
+ * under the lock, but as we perform the lookup of the object and
+ * its activity locklessly we can not guarantee that the last_write
+ * being active implies that we have set the same engine flag from
+ * last_read - hence we always set both read and write busy for
+ * last_write.
+ */
+ if (id == (u8)I915_ENGINE_CLASS_INVALID)
+ return 0xffffffffu;
+
+ return (id + 1) | __busy_read_flag(id);
+}
+
+static __always_inline unsigned int
+__busy_set_if_active(const struct dma_fence *fence, u32 (*flag)(u8 id))
+{
+ const struct i915_request *rq;
+
+ /*
+ * We have to check the current hw status of the fence as the uABI
+ * guarantees forward progress. We could rely on the idle worker
+ * to eventually flush us, but to minimise latency just ask the
+ * hardware.
+ *
+ * Note we only report on the status of native fences.
+ */
+ if (!dma_fence_is_i915(fence))
+ return 0;
+
+ /* opencode to_request() in order to avoid const warnings */
+ rq = container_of(fence, const struct i915_request, fence);
+ if (i915_request_completed(rq))
+ return 0;
+
+ /* Beware type-expansion follies! */
+ BUILD_BUG_ON(!typecheck(u8, rq->engine->uabi_class));
+ return flag(rq->engine->uabi_class);
+}
+
+static __always_inline unsigned int
+busy_check_reader(const struct dma_fence *fence)
+{
+ return __busy_set_if_active(fence, __busy_read_flag);
+}
+
+static __always_inline unsigned int
+busy_check_writer(const struct dma_fence *fence)
+{
+ if (!fence)
+ return 0;
+
+ return __busy_set_if_active(fence, __busy_write_id);
+}
+
+int
+i915_gem_busy_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_i915_gem_busy *args = data;
+ struct drm_i915_gem_object *obj;
+ struct reservation_object_list *list;
+ unsigned int seq;
+ int err;
+
+ err = -ENOENT;
+ rcu_read_lock();
+ obj = i915_gem_object_lookup_rcu(file, args->handle);
+ if (!obj)
+ goto out;
+
+ /*
+ * A discrepancy here is that we do not report the status of
+ * non-i915 fences, i.e. even though we may report the object as idle,
+ * a call to set-domain may still stall waiting for foreign rendering.
+ * This also means that wait-ioctl may report an object as busy,
+ * where busy-ioctl considers it idle.
+ *
+ * We trade the ability to warn of foreign fences to report on which
+ * i915 engines are active for the object.
+ *
+ * Alternatively, we can trade that extra information on read/write
+ * activity with
+ * args->busy =
+ * !reservation_object_test_signaled_rcu(obj->resv, true);
+ * to report the overall busyness. This is what the wait-ioctl does.
+ *
+ */
+retry:
+ seq = raw_read_seqcount(&obj->resv->seq);
+
+ /* Translate the exclusive fence to the READ *and* WRITE engine */
+ args->busy = busy_check_writer(rcu_dereference(obj->resv->fence_excl));
+
+ /* Translate shared fences to READ set of engines */
+ list = rcu_dereference(obj->resv->fence);
+ if (list) {
+ unsigned int shared_count = list->shared_count, i;
+
+ for (i = 0; i < shared_count; ++i) {
+ struct dma_fence *fence =
+ rcu_dereference(list->shared[i]);
+
+ args->busy |= busy_check_reader(fence);
+ }
+ }
+
+ if (args->busy && read_seqcount_retry(&obj->resv->seq, seq))
+ goto retry;
+
+ err = 0;
+out:
+ rcu_read_unlock();
+ return err;
+}
return vma;
}
-static __always_inline u32 __busy_read_flag(u8 id)
-{
- if (id == (u8)I915_ENGINE_CLASS_INVALID)
- return 0xffff0000u;
-
- GEM_BUG_ON(id >= 16);
- return 0x10000u << id;
-}
-
-static __always_inline u32 __busy_write_id(u8 id)
-{
- /*
- * The uABI guarantees an active writer is also amongst the read
- * engines. This would be true if we accessed the activity tracking
- * under the lock, but as we perform the lookup of the object and
- * its activity locklessly we can not guarantee that the last_write
- * being active implies that we have set the same engine flag from
- * last_read - hence we always set both read and write busy for
- * last_write.
- */
- if (id == (u8)I915_ENGINE_CLASS_INVALID)
- return 0xffffffffu;
-
- return (id + 1) | __busy_read_flag(id);
-}
-
-static __always_inline unsigned int
-__busy_set_if_active(const struct dma_fence *fence, u32 (*flag)(u8 id))
-{
- const struct i915_request *rq;
-
- /*
- * We have to check the current hw status of the fence as the uABI
- * guarantees forward progress. We could rely on the idle worker
- * to eventually flush us, but to minimise latency just ask the
- * hardware.
- *
- * Note we only report on the status of native fences.
- */
- if (!dma_fence_is_i915(fence))
- return 0;
-
- /* opencode to_request() in order to avoid const warnings */
- rq = container_of(fence, const struct i915_request, fence);
- if (i915_request_completed(rq))
- return 0;
-
- /* Beware type-expansion follies! */
- BUILD_BUG_ON(!typecheck(u8, rq->engine->uabi_class));
- return flag(rq->engine->uabi_class);
-}
-
-static __always_inline unsigned int
-busy_check_reader(const struct dma_fence *fence)
-{
- return __busy_set_if_active(fence, __busy_read_flag);
-}
-
-static __always_inline unsigned int
-busy_check_writer(const struct dma_fence *fence)
-{
- if (!fence)
- return 0;
-
- return __busy_set_if_active(fence, __busy_write_id);
-}
-
-int
-i915_gem_busy_ioctl(struct drm_device *dev, void *data,
- struct drm_file *file)
-{
- struct drm_i915_gem_busy *args = data;
- struct drm_i915_gem_object *obj;
- struct reservation_object_list *list;
- unsigned int seq;
- int err;
-
- err = -ENOENT;
- rcu_read_lock();
- obj = i915_gem_object_lookup_rcu(file, args->handle);
- if (!obj)
- goto out;
-
- /*
- * A discrepancy here is that we do not report the status of
- * non-i915 fences, i.e. even though we may report the object as idle,
- * a call to set-domain may still stall waiting for foreign rendering.
- * This also means that wait-ioctl may report an object as busy,
- * where busy-ioctl considers it idle.
- *
- * We trade the ability to warn of foreign fences to report on which
- * i915 engines are active for the object.
- *
- * Alternatively, we can trade that extra information on read/write
- * activity with
- * args->busy =
- * !reservation_object_test_signaled_rcu(obj->resv, true);
- * to report the overall busyness. This is what the wait-ioctl does.
- *
- */
-retry:
- seq = raw_read_seqcount(&obj->resv->seq);
-
- /* Translate the exclusive fence to the READ *and* WRITE engine */
- args->busy = busy_check_writer(rcu_dereference(obj->resv->fence_excl));
-
- /* Translate shared fences to READ set of engines */
- list = rcu_dereference(obj->resv->fence);
- if (list) {
- unsigned int shared_count = list->shared_count, i;
-
- for (i = 0; i < shared_count; ++i) {
- struct dma_fence *fence =
- rcu_dereference(list->shared[i]);
-
- args->busy |= busy_check_reader(fence);
- }
- }
-
- if (args->busy && read_seqcount_retry(&obj->resv->seq, seq))
- goto retry;
-
- err = 0;
-out:
- rcu_read_unlock();
- return err;
-}
-
int
i915_gem_throttle_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
projects / linux.git / commitdiff