From 23ba4fd0a42a46551041e379712e808ad496ba45 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Thu, 24 May 2012 15:03:10 -0700 Subject: [PATCH] drm/i915: wait render timeout ioctl This helps implement GL_ARB_sync but stops short of allowing full blown sync objects. Finally we can use the new timed seqno waiting function to allow userspace to wait on a buffer object with a timeout. This implements that interface. The IOCTL will take as input a buffer object handle, and a timeout in nanoseconds (flags is currently optional but will likely be used for permutations of flush operations). Users may specify 0 nanoseconds to instantly check. The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any non-zero timeout parameter the wait ioctl will wait for the given number of nanoseconds on an object becoming unbusy. Since the wait itself does so holding struct_mutex the object may become re-busied before this completes. A similar but shorter race condition exists in the busy ioctl. v2: ETIME/ERESTARTSYS instead of changing to EBUSY, and EGAIN (Chris) Flush the object from the gpu write domain (Chris + Daniel) Fix leaked refcount in good case (Chris) Naturally align ioctl struct (Chris) v3: Drop lock after getting seqno to avoid ugly dance (Chris) v4: check for 0 timeout after olr check to allow polling (Chris) v5: Updated the comment. (Chris) v6: Return -ETIME instead of -EBUSY when timeout_ns is 0 (Daniel) Fix the commit message comment to be less ugly (Ben) Add a warning to check the return timespec (Ben) v7: Use DRM_AUTH for the ioctl. (Eugeni) Signed-off-by: Ben Widawsky Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_dma.c | 1 + drivers/gpu/drm/i915/i915_drv.h | 2 + drivers/gpu/drm/i915/i915_gem.c | 86 +++++++++++++++++++++++++++++++++++++++++ include/drm/i915_drm.h | 10 +++++ 4 files changed, 99 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index f947926..262a74d 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1803,6 +1803,7 @@ struct drm_ioctl_desc i915_ioctls[] = { DRM_IOCTL_DEF_DRV(I915_OVERLAY_ATTRS, intel_overlay_attrs, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED), DRM_IOCTL_DEF_DRV(I915_SET_SPRITE_COLORKEY, intel_sprite_set_colorkey, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED), DRM_IOCTL_DEF_DRV(I915_GET_SPRITE_COLORKEY, intel_sprite_get_colorkey, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED), + DRM_IOCTL_DEF_DRV(I915_GEM_WAIT, i915_gem_wait_ioctl, DRM_AUTH|DRM_UNLOCKED), }; int i915_max_ioctl = DRM_ARRAY_SIZE(i915_ioctls); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 11c7a6a..8ac10e8 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1229,6 +1229,8 @@ int i915_gem_get_tiling(struct drm_device *dev, void *data, struct drm_file *file_priv); int i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv); +int i915_gem_wait_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_priv); void i915_gem_load(struct drm_device *dev); int i915_gem_init_object(struct drm_gem_object *obj); int __must_check i915_gem_flush_ring(struct intel_ring_buffer *ring, diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index c8a5b04..a0d740f 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2001,6 +2001,92 @@ i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj) } /** + * i915_gem_wait_ioctl - implements DRM_IOCTL_I915_GEM_WAIT + * @DRM_IOCTL_ARGS: standard ioctl arguments + * + * Returns 0 if successful, else an error is returned with the remaining time in + * the timeout parameter. + * -ETIME: object is still busy after timeout + * -ERESTARTSYS: signal interrupted the wait + * -ENONENT: object doesn't exist + * Also possible, but rare: + * -EAGAIN: GPU wedged + * -ENOMEM: damn + * -ENODEV: Internal IRQ fail + * -E?: The add request failed + * + * The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any + * non-zero timeout parameter the wait ioctl will wait for the given number of + * nanoseconds on an object becoming unbusy. Since the wait itself does so + * without holding struct_mutex the object may become re-busied before this + * function completes. A similar but shorter * race condition exists in the busy + * ioctl + */ +int +i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) +{ + struct drm_i915_gem_wait *args = data; + struct drm_i915_gem_object *obj; + struct intel_ring_buffer *ring = NULL; + struct timespec timeout; + u32 seqno = 0; + int ret = 0; + + timeout = ns_to_timespec(args->timeout_ns); + + ret = i915_mutex_lock_interruptible(dev); + if (ret) + return ret; + + obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->bo_handle)); + if (&obj->base == NULL) { + mutex_unlock(&dev->struct_mutex); + return -ENOENT; + } + + /* Need to make sure the object is flushed first. This non-obvious + * flush is required to enforce that (active && !olr) == no wait + * necessary. + */ + ret = i915_gem_object_flush_gpu_write_domain(obj); + if (ret) + goto out; + + if (obj->active) { + seqno = obj->last_rendering_seqno; + ring = obj->ring; + } + + if (seqno == 0) + goto out; + + ret = i915_gem_check_olr(ring, seqno); + if (ret) + goto out; + + /* Do this after OLR check to make sure we make forward progress polling + * on this IOCTL with a 0 timeout (like busy ioctl) + */ + if (!args->timeout_ns) { + ret = -ETIME; + goto out; + } + + drm_gem_object_unreference(&obj->base); + mutex_unlock(&dev->struct_mutex); + + ret = __wait_seqno(ring, seqno, true, &timeout); + WARN_ON(!timespec_valid(&timeout)); + args->timeout_ns = timespec_to_ns(&timeout); + return ret; + +out: + drm_gem_object_unreference(&obj->base); + mutex_unlock(&dev->struct_mutex); + return ret; +} + +/** * i915_gem_object_sync - sync an object to a ring. * * @obj: object which may be in use on another ring. diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h index f3f8224..bab1743 100644 --- a/include/drm/i915_drm.h +++ b/include/drm/i915_drm.h @@ -200,6 +200,7 @@ typedef struct _drm_i915_sarea { #define DRM_I915_GEM_EXECBUFFER2 0x29 #define DRM_I915_GET_SPRITE_COLORKEY 0x2a #define DRM_I915_SET_SPRITE_COLORKEY 0x2b +#define DRM_I915_GEM_WAIT 0x2c #define DRM_IOCTL_I915_INIT DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t) #define DRM_IOCTL_I915_FLUSH DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH) @@ -243,6 +244,7 @@ typedef struct _drm_i915_sarea { #define DRM_IOCTL_I915_OVERLAY_ATTRS DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_OVERLAY_ATTRS, struct drm_intel_overlay_attrs) #define DRM_IOCTL_I915_SET_SPRITE_COLORKEY DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_SET_SPRITE_COLORKEY, struct drm_intel_sprite_colorkey) #define DRM_IOCTL_I915_GET_SPRITE_COLORKEY DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_SET_SPRITE_COLORKEY, struct drm_intel_sprite_colorkey) +#define DRM_IOCTL_I915_GEM_WAIT DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_WAIT, struct drm_i915_gem_wait) /* Allow drivers to submit batchbuffers directly to hardware, relying * on the security mechanisms provided by hardware. @@ -886,4 +888,12 @@ struct drm_intel_sprite_colorkey { __u32 flags; }; +struct drm_i915_gem_wait { + /** Handle of BO we shall wait on */ + __u32 bo_handle; + __u32 flags; + /** Number of nanoseconds to wait, Returns time remaining. */ + __u64 timeout_ns; +}; + #endif /* _I915_DRM_H_ */ -- 2.7.4