diff options
Diffstat (limited to 'drivers/dma-buf')
| -rw-r--r-- | drivers/dma-buf/dma-buf.c | 2 | ||||
| -rw-r--r-- | drivers/dma-buf/dma-fence-array.c | 11 | ||||
| -rw-r--r-- | drivers/dma-buf/dma-fence-chain.c | 12 | ||||
| -rw-r--r-- | drivers/dma-buf/dma-fence.c | 59 | ||||
| -rw-r--r-- | drivers/dma-buf/dma-resv.c | 22 |
5 files changed, 105 insertions, 1 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 757c0fb77a6c..aa4ea8530cb3 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -828,7 +828,7 @@ static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach, * - dma_buf_attach() * - dma_buf_dynamic_attach() * - dma_buf_detach() - * - dma_buf_export( + * - dma_buf_export() * - dma_buf_fd() * - dma_buf_get() * - dma_buf_put() diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c index 5c8a7084577b..9b3ce8948351 100644 --- a/drivers/dma-buf/dma-fence-array.c +++ b/drivers/dma-buf/dma-fence-array.c @@ -123,12 +123,23 @@ static void dma_fence_array_release(struct dma_fence *fence) dma_fence_free(fence); } +static void dma_fence_array_set_deadline(struct dma_fence *fence, + ktime_t deadline) +{ + struct dma_fence_array *array = to_dma_fence_array(fence); + unsigned i; + + for (i = 0; i < array->num_fences; ++i) + dma_fence_set_deadline(array->fences[i], deadline); +} + const struct dma_fence_ops dma_fence_array_ops = { .get_driver_name = dma_fence_array_get_driver_name, .get_timeline_name = dma_fence_array_get_timeline_name, .enable_signaling = dma_fence_array_enable_signaling, .signaled = dma_fence_array_signaled, .release = dma_fence_array_release, + .set_deadline = dma_fence_array_set_deadline, }; EXPORT_SYMBOL(dma_fence_array_ops); diff --git a/drivers/dma-buf/dma-fence-chain.c b/drivers/dma-buf/dma-fence-chain.c index a0d920576ba6..9663ba1bb6ac 100644 --- a/drivers/dma-buf/dma-fence-chain.c +++ b/drivers/dma-buf/dma-fence-chain.c @@ -206,6 +206,17 @@ static void dma_fence_chain_release(struct dma_fence *fence) dma_fence_free(fence); } + +static void dma_fence_chain_set_deadline(struct dma_fence *fence, + ktime_t deadline) +{ + dma_fence_chain_for_each(fence, fence) { + struct dma_fence *f = dma_fence_chain_contained(fence); + + dma_fence_set_deadline(f, deadline); + } +} + const struct dma_fence_ops dma_fence_chain_ops = { .use_64bit_seqno = true, .get_driver_name = dma_fence_chain_get_driver_name, @@ -213,6 +224,7 @@ const struct dma_fence_ops dma_fence_chain_ops = { .enable_signaling = dma_fence_chain_enable_signaling, .signaled = dma_fence_chain_signaled, .release = dma_fence_chain_release, + .set_deadline = dma_fence_chain_set_deadline, }; EXPORT_SYMBOL(dma_fence_chain_ops); diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 0de0482cd36e..f177c56269bb 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -913,6 +913,65 @@ err_free_cb: EXPORT_SYMBOL(dma_fence_wait_any_timeout); /** + * DOC: deadline hints + * + * In an ideal world, it would be possible to pipeline a workload sufficiently + * that a utilization based device frequency governor could arrive at a minimum + * frequency that meets the requirements of the use-case, in order to minimize + * power consumption. But in the real world there are many workloads which + * defy this ideal. For example, but not limited to: + * + * * Workloads that ping-pong between device and CPU, with alternating periods + * of CPU waiting for device, and device waiting on CPU. This can result in + * devfreq and cpufreq seeing idle time in their respective domains and in + * result reduce frequency. + * + * * Workloads that interact with a periodic time based deadline, such as double + * buffered GPU rendering vs vblank sync'd page flipping. In this scenario, + * missing a vblank deadline results in an *increase* in idle time on the GPU + * (since it has to wait an additional vblank period), sending a signal to + * the GPU's devfreq to reduce frequency, when in fact the opposite is what is + * needed. + * + * To this end, deadline hint(s) can be set on a &dma_fence via &dma_fence_set_deadline. + * The deadline hint provides a way for the waiting driver, or userspace, to + * convey an appropriate sense of urgency to the signaling driver. + * + * A deadline hint is given in absolute ktime (CLOCK_MONOTONIC for userspace + * facing APIs). The time could either be some point in the future (such as + * the vblank based deadline for page-flipping, or the start of a compositor's + * composition cycle), or the current time to indicate an immediate deadline + * hint (Ie. forward progress cannot be made until this fence is signaled). + * + * Multiple deadlines may be set on a given fence, even in parallel. See the + * documentation for &dma_fence_ops.set_deadline. + * + * The deadline hint is just that, a hint. The driver that created the fence + * may react by increasing frequency, making different scheduling choices, etc. + * Or doing nothing at all. + */ + +/** + * dma_fence_set_deadline - set desired fence-wait deadline hint + * @fence: the fence that is to be waited on + * @deadline: the time by which the waiter hopes for the fence to be + * signaled + * + * Give the fence signaler a hint about an upcoming deadline, such as + * vblank, by which point the waiter would prefer the fence to be + * signaled by. This is intended to give feedback to the fence signaler + * to aid in power management decisions, such as boosting GPU frequency + * if a periodic vblank deadline is approaching but the fence is not + * yet signaled.. + */ +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline) +{ + if (fence->ops->set_deadline && !dma_fence_is_signaled(fence)) + fence->ops->set_deadline(fence, deadline); +} +EXPORT_SYMBOL(dma_fence_set_deadline); + +/** * dma_fence_describe - Dump fence describtion into seq_file * @fence: the 6fence to describe * @seq: the seq_file to put the textual description into diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 1c76aed8e262..2a594b754af1 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -684,6 +684,28 @@ long dma_resv_wait_timeout(struct dma_resv *obj, enum dma_resv_usage usage, } EXPORT_SYMBOL_GPL(dma_resv_wait_timeout); +/** + * dma_resv_set_deadline - Set a deadline on reservation's objects fences + * @obj: the reservation object + * @usage: controls which fences to include, see enum dma_resv_usage. + * @deadline: the requested deadline (MONOTONIC) + * + * May be called without holding the dma_resv lock. Sets @deadline on + * all fences filtered by @usage. + */ +void dma_resv_set_deadline(struct dma_resv *obj, enum dma_resv_usage usage, + ktime_t deadline) +{ + struct dma_resv_iter cursor; + struct dma_fence *fence; + + dma_resv_iter_begin(&cursor, obj, usage); + dma_resv_for_each_fence_unlocked(&cursor, fence) { + dma_fence_set_deadline(fence, deadline); + } + dma_resv_iter_end(&cursor); +} +EXPORT_SYMBOL_GPL(dma_resv_set_deadline); /** * dma_resv_test_signaled - Test if a reservation object's fences have been |