diff options
| -rw-r--r-- | drivers/gpu/drm/i915/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_busy.c | 138 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 128 |
3 files changed, 139 insertions, 128 deletions
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index a4ea6f6b2ab7..e1ed526b96bf 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -88,6 +88,7 @@ i915-y += $(gt-y) # GEM (Graphics Execution Management) code obj-y += gem/ gem-y += \ + gem/i915_gem_busy.o \ gem/i915_gem_clflush.o \ gem/i915_gem_context.o \ gem/i915_gem_dmabuf.o \ diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c new file mode 100644 index 000000000000..5a5eda3003e9 --- /dev/null +++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c @@ -0,0 +1,138 @@ +/* + * 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; +} diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index a460563e4bb5..6af448736030 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1142,134 +1142,6 @@ i915_gem_object_ggtt_pin(struct drm_i915_gem_object *obj, 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) |