<div dir="ltr"><div dir="ltr"> </div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jan 13, 2020 at 8:25 AM Rob Clark <<a href="mailto:robdclark@chromium.org">robdclark@chromium.org</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Mon, Jan 13, 2020 at 7:37 AM Brian Ho <<a href="mailto:brian@brkho.com" target="_blank">brian@brkho.com</a>> wrote: > > Implements an ioctl to wait until a value at a given iova is greater > than or equal to a supplied value. > > This will initially be used by turnip (open-source Vulkan driver for > QC in mesa) for occlusion queries where the userspace driver can > block on a query becoming available before continuing via > vkGetQueryPoolResults. > > Signed-off-by: Brian Ho <<a href="mailto:brian@brkho.com" target="_blank">brian@brkho.com</a>> > --- > drivers/gpu/drm/msm/msm_drv.c | 63 +++++++++++++++++++++++++++++++++-- > include/uapi/drm/msm_drm.h | 13 ++++++++ > 2 files changed, 74 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c > index c84f0a8b3f2c..dcc46874a5a2 100644 > --- a/drivers/gpu/drm/msm/msm_drv.c > +++ b/drivers/gpu/drm/msm/msm_drv.c > @@ -36,10 +36,11 @@ > * MSM_GEM_INFO ioctl. > * - 1.4.0 - softpin, MSM_RELOC_BO_DUMP, and GEM_INFO support to set/get > * GEM object's debug name > - * - 1.5.0 - Add SUBMITQUERY_QUERY ioctl > + * - 1.5.0 - Add SUBMITQUEUE_QUERY ioctl > + * - 1.6.0 - Add WAIT_IOVA ioctl > */ > #define MSM_VERSION_MAJOR 1 > -#define MSM_VERSION_MINOR 5 > +#define MSM_VERSION_MINOR 6 > #define MSM_VERSION_PATCHLEVEL 0 > > static const struct drm_mode_config_funcs mode_config_funcs = { > @@ -952,6 +953,63 @@ static int msm_ioctl_submitqueue_close(struct drm_device *dev, void *data, > return msm_submitqueue_remove(file->driver_priv, id); > } > > +static int msm_ioctl_wait_iova(struct drm_device *dev, void *data, > + struct drm_file *file) > +{ > + struct msm_drm_private *priv = dev->dev_private; > + struct drm_gem_object *obj; > + struct drm_msm_wait_iova *args = data; > + ktime_t timeout = to_ktime(args->timeout); > + unsigned long remaining_jiffies = timeout_to_jiffies(&timeout); > + struct msm_gpu *gpu = priv->gpu; > + void *base_vaddr; > + uint64_t *vaddr; > + int ret; > + > + if (args->pad) > + return -EINVAL; > + > + if (!gpu) > + return 0; hmm, I'm not sure we should return zero in this case.. maybe -ENODEV? > + > + obj = drm_gem_object_lookup(file, args->handle); > + if (!obj) > + return -ENOENT; > + > + base_vaddr = msm_gem_get_vaddr(obj); > + if (IS_ERR(base_vaddr)) { > + ret = PTR_ERR(base_vaddr); > + goto err_put_gem_object; > + } > + if (args->offset + sizeof(*vaddr) > obj->size) { > + ret = -EINVAL; > + goto err_put_vaddr; > + } > + > + vaddr = base_vaddr + args->offset; > + > + /* Assumes WC mapping */ > + ret = wait_event_interruptible_timeout( > + gpu->event, *vaddr >= args->value, remaining_jiffies); </blockquote><div> </div><div>This needs to do the awkward looking</div><div> </div><div> (int64_t)(*data - value) >= 0 </div><div> </div><div>to properly handle the wraparound case.</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> > + > + if (ret == 0) { > + ret = -ETIMEDOUT; > + goto err_put_vaddr; > + } else if (ret == -ERESTARTSYS) { > + goto err_put_vaddr; > + } maybe: } else { ret = 0; } and then drop the next three lines? > + > + msm_gem_put_vaddr(obj); > + drm_gem_object_put_unlocked(obj); > + return 0; > + > +err_put_vaddr: > + msm_gem_put_vaddr(obj); > +err_put_gem_object: > + drm_gem_object_put_unlocked(obj); > + return ret; > +} > + > static const struct drm_ioctl_desc msm_ioctls[] = { > DRM_IOCTL_DEF_DRV(MSM_GET_PARAM, msm_ioctl_get_param, DRM_RENDER_ALLOW), > DRM_IOCTL_DEF_DRV(MSM_GEM_NEW, msm_ioctl_gem_new, DRM_RENDER_ALLOW), > @@ -964,6 +1022,7 @@ static const struct drm_ioctl_desc msm_ioctls[] = { > DRM_IOCTL_DEF_DRV(MSM_SUBMITQUEUE_NEW, msm_ioctl_submitqueue_new, DRM_RENDER_ALLOW), > DRM_IOCTL_DEF_DRV(MSM_SUBMITQUEUE_CLOSE, msm_ioctl_submitqueue_close, DRM_RENDER_ALLOW), > DRM_IOCTL_DEF_DRV(MSM_SUBMITQUEUE_QUERY, msm_ioctl_submitqueue_query, DRM_RENDER_ALLOW), > + DRM_IOCTL_DEF_DRV(MSM_WAIT_IOVA, msm_ioctl_wait_iova, DRM_RENDER_ALLOW), > }; > > static const struct vm_operations_struct vm_ops = { > diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h > index 0b85ed6a3710..8477f28a4ee1 100644 > --- a/include/uapi/drm/msm_drm.h > +++ b/include/uapi/drm/msm_drm.h > @@ -298,6 +298,17 @@ struct drm_msm_submitqueue_query { > __u32 pad; > }; > > +/* This ioctl blocks until the u64 value at bo + offset is greater than or > + * equal to the reference value. > + */ > +struct drm_msm_wait_iova { > + __u32 handle; /* in, GEM handle */ > + __u32 pad; > + struct drm_msm_timespec timeout; /* in */ > + __u64 offset; /* offset into bo */ > + __u64 value; /* reference value */ Maybe we should go ahead and add a __u64 mask; that would let us wait for 32b values as well, and wait for bits in a bitmask </blockquote><div> </div><div>I think we'd be OK to just default to 32 bit values instead, since most of the CP commands that this is intended to work with (CP_EVENT_WRITE, CP_WAIT_MEM_GTE etc) operate on 32 bit values. We could move 'value' to the slot right after 'handle' but then we'd not have any pad/reserved fields. Maybe we keep 'value' 64 bit but restrict it to 32 bits, with an option to add a 64 bit flag in 'pad' later on?</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> Other than those minor comments, it looks pretty good to me BR, -R > +}; > + > #define DRM_MSM_GET_PARAM 0x00 > /* placeholder: > #define DRM_MSM_SET_PARAM 0x01 > @@ -315,6 +326,7 @@ struct drm_msm_submitqueue_query { > #define DRM_MSM_SUBMITQUEUE_NEW 0x0A > #define DRM_MSM_SUBMITQUEUE_CLOSE 0x0B > #define DRM_MSM_SUBMITQUEUE_QUERY 0x0C > +#define DRM_MSM_WAIT_IOVA 0x0D > > #define DRM_IOCTL_MSM_GET_PARAM DRM_IOWR(DRM_COMMAND_BASE + DRM_MSM_GET_PARAM, struct drm_msm_param) > #define DRM_IOCTL_MSM_GEM_NEW DRM_IOWR(DRM_COMMAND_BASE + DRM_MSM_GEM_NEW, struct drm_msm_gem_new) > @@ -327,6 +339,7 @@ struct drm_msm_submitqueue_query { > #define DRM_IOCTL_MSM_SUBMITQUEUE_NEW DRM_IOWR(DRM_COMMAND_BASE + DRM_MSM_SUBMITQUEUE_NEW, struct drm_msm_submitqueue) > #define DRM_IOCTL_MSM_SUBMITQUEUE_CLOSE DRM_IOW (DRM_COMMAND_BASE + DRM_MSM_SUBMITQUEUE_CLOSE, __u32) > #define DRM_IOCTL_MSM_SUBMITQUEUE_QUERY DRM_IOW (DRM_COMMAND_BASE + DRM_MSM_SUBMITQUEUE_QUERY, struct drm_msm_submitqueue_query) > +#define DRM_IOCTL_MSM_WAIT_IOVA DRM_IOW (DRM_COMMAND_BASE + DRM_MSM_WAIT_IOVA, struct drm_msm_wait_iova) > > #if defined(__cplusplus) > } > -- > 2.25.0.rc1.283.g88dfdc4193-goog > </blockquote></div></div>