From: Rob Clark robdclark@chromium.org

This consists of simply storing the most recent deadline, and adding an ioctl to retrieve the deadline. This can be used in conjunction with the SET_DEADLINE ioctl on a fence fd for testing. Ie. create various sw_sync fences, merge them into a fence-array, set deadline on the fence-array and confirm that it is propagated properly to each fence.

v2: Switch UABI to express deadline as u64 v3: More verbose UAPI docs, show how to convert from timespec v4: Better comments, track the soonest deadline, as a normal fence implementation would, return an error if no deadline set.

Signed-off-by: Rob Clark robdclark@chromium.org Reviewed-by: Christian König christian.koenig@amd.com Acked-by: Pekka Paalanen pekka.paalanen@collabora.com --- drivers/dma-buf/sw_sync.c | 82 ++++++++++++++++++++++++++++++++++++ drivers/dma-buf/sync_debug.h | 2 + 2 files changed, 84 insertions(+)

diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c index f0a35277fd84..c353029789cf 100644 --- a/drivers/dma-buf/sw_sync.c +++ b/drivers/dma-buf/sw_sync.c @@ -52,12 +52,33 @@ struct sw_sync_create_fence_data { __s32 fence; /* fd of new fence */ };

+/** + * struct sw_sync_get_deadline - get the deadline hint of a sw_sync fence + * @deadline_ns: absolute time of the deadline + * @pad: must be zero + * @fence_fd: the sw_sync fence fd (in) + * + * Return the earliest deadline set on the fence. The timebase for the + * deadline is CLOCK_MONOTONIC (same as vblank). If there is no deadline + * set on the fence, this ioctl will return -ENOENT. + */ +struct sw_sync_get_deadline { + __u64 deadline_ns; + __u32 pad; + __s32 fence_fd; +}; + #define SW_SYNC_IOC_MAGIC 'W'

#define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0,\ struct sw_sync_create_fence_data)

#define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32) +#define SW_SYNC_GET_DEADLINE _IOWR(SW_SYNC_IOC_MAGIC, 2, \ + struct sw_sync_get_deadline) + + +#define SW_SYNC_HAS_DEADLINE_BIT DMA_FENCE_FLAG_USER_BITS

static const struct dma_fence_ops timeline_fence_ops;

@@ -171,6 +192,22 @@ static void timeline_fence_timeline_value_str(struct dma_fence *fence, snprintf(str, size, "%d", parent->value); }

+static void timeline_fence_set_deadline(struct dma_fence *fence, ktime_t deadline) +{ + struct sync_pt *pt = dma_fence_to_sync_pt(fence); + unsigned long flags; + + spin_lock_irqsave(fence->lock, flags); + if (test_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags)) { + if (ktime_before(deadline, pt->deadline)) + pt->deadline = deadline; + } else { + pt->deadline = deadline; + __set_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags); + } + spin_unlock_irqrestore(fence->lock, flags); +} + static const struct dma_fence_ops timeline_fence_ops = { .get_driver_name = timeline_fence_get_driver_name, .get_timeline_name = timeline_fence_get_timeline_name, @@ -179,6 +216,7 @@ static const struct dma_fence_ops timeline_fence_ops = { .release = timeline_fence_release, .fence_value_str = timeline_fence_value_str, .timeline_value_str = timeline_fence_timeline_value_str, + .set_deadline = timeline_fence_set_deadline, };

/** @@ -387,6 +425,47 @@ static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg) return 0; }

+static int sw_sync_ioctl_get_deadline(struct sync_timeline *obj, unsigned long arg) +{ + struct sw_sync_get_deadline data; + struct dma_fence *fence; + unsigned long flags; + struct sync_pt *pt; + int ret = 0; + + if (copy_from_user(&data, (void __user *)arg, sizeof(data))) + return -EFAULT; + + if (data.deadline_ns || data.pad) + return -EINVAL; + + fence = sync_file_get_fence(data.fence_fd); + if (!fence) + return -EINVAL; + + pt = dma_fence_to_sync_pt(fence); + if (!pt) + return -EINVAL; + + spin_lock_irqsave(fence->lock, flags); + if (test_bit(SW_SYNC_HAS_DEADLINE_BIT, &fence->flags)) { + data.deadline_ns = ktime_to_ns(pt->deadline); + } else { + ret = -ENOENT; + } + spin_unlock_irqrestore(fence->lock, flags); + + dma_fence_put(fence); + + if (ret) + return ret; + + if (copy_to_user((void __user *)arg, &data, sizeof(data))) + return -EFAULT; + + return 0; +} + static long sw_sync_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -399,6 +478,9 @@ static long sw_sync_ioctl(struct file *file, unsigned int cmd, case SW_SYNC_IOC_INC: return sw_sync_ioctl_inc(obj, arg);

+ case SW_SYNC_GET_DEADLINE: + return sw_sync_ioctl_get_deadline(obj, arg); + default: return -ENOTTY; } diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h index 6176e52ba2d7..a1bdd62efccd 100644 --- a/drivers/dma-buf/sync_debug.h +++ b/drivers/dma-buf/sync_debug.h @@ -55,11 +55,13 @@ static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence) * @base: base fence object * @link: link on the sync timeline's list * @node: node in the sync timeline's tree + * @deadline: the earliest fence deadline hint */ struct sync_pt { struct dma_fence base; struct list_head link; struct rb_node node; + ktime_t deadline; };

extern const struct file_operations sw_sync_debugfs_fops;