On Fri, Oct 27, 2023 at 6:16 PM Dmitry Baryshkov <dmitry.barysh...@linaro.org> wrote: > > On Fri, 27 Oct 2023 at 22:45, Rob Clark <robdcl...@gmail.com> wrote: > > > > From: Rob Clark <robdcl...@chromium.org> > > > > The EXT_external_objects extension is a bit awkward as it doesn't pass > > explicit modifiers, leaving the importer to guess with incomplete > > information. In the case of vk (turnip) exporting and gl (freedreno) > > importing, the "OPTIMAL_TILING_EXT" layout depends on VkImageCreateInfo > > flags (among other things), which the importer does not know. Which > > unfortunately leaves us with the need for a metadata back-channel. > > > > The contents of the metadata are defined by userspace. The > > EXT_external_objects extension is only required to work between > > compatible versions of gl and vk drivers, as defined by device and > > driver UUIDs.
jfyi, userspace side of this at: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25945 > > > > Signed-off-by: Rob Clark <robdcl...@chromium.org> > > --- > > drivers/gpu/drm/msm/msm_drv.c | 59 +++++++++++++++++++++++++++++++++-- > > drivers/gpu/drm/msm/msm_gem.h | 4 +++ > > include/uapi/drm/msm_drm.h | 2 ++ > > 3 files changed, 63 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c > > index b61ccea05327..8fe2677ea37a 100644 > > --- a/drivers/gpu/drm/msm/msm_drv.c > > +++ b/drivers/gpu/drm/msm/msm_drv.c > > @@ -37,9 +37,10 @@ > > * - 1.9.0 - Add MSM_SUBMIT_FENCE_SN_IN > > * - 1.10.0 - Add MSM_SUBMIT_BO_NO_IMPLICIT > > * - 1.11.0 - Add wait boost (MSM_WAIT_FENCE_BOOST, MSM_PREP_BOOST) > > + * - 1.12.0 - Add MSM_INFO_SET_METADATA and MSM_INFO_GET_METADATA > > */ > > #define MSM_VERSION_MAJOR 1 > > -#define MSM_VERSION_MINOR 10 > > +#define MSM_VERSION_MINOR 12 > > #define MSM_VERSION_PATCHLEVEL 0 > > > > static void msm_deinit_vram(struct drm_device *ddev); > > @@ -566,6 +567,8 @@ static int msm_ioctl_gem_info(struct drm_device *dev, > > void *data, > > break; > > case MSM_INFO_SET_NAME: > > case MSM_INFO_GET_NAME: > > + case MSM_INFO_SET_METADATA: > > + case MSM_INFO_GET_METADATA: > > break; > > default: > > return -EINVAL; > > @@ -618,7 +621,7 @@ static int msm_ioctl_gem_info(struct drm_device *dev, > > void *data, > > break; > > case MSM_INFO_GET_NAME: > > if (args->value && (args->len < strlen(msm_obj->name))) { > > - ret = -EINVAL; > > + ret = -ETOOSMALL; > > This is unrelated and it also slightly changes user interface, so it > IMO should come as a separate commit/ fair, although it was changed for consistency with GET_METADATA > > break; > > } > > args->len = strlen(msm_obj->name); > > @@ -627,6 +630,58 @@ static int msm_ioctl_gem_info(struct drm_device *dev, > > void *data, > > msm_obj->name, args->len)) > > ret = -EFAULT; > > } > > + break; > > + case MSM_INFO_SET_METADATA: > > + /* Impose a moderate upper bound on metadata size: */ > > + if (args->len > 128) { > > + ret = -EOVERFLOW; > > + break; > > + } > > + > > + ret = msm_gem_lock_interruptible(obj); > > + if (ret) > > + break; > > + > > + msm_obj->metadata = > > + krealloc(msm_obj->metadata, args->len, GFP_KERNEL); > > + msm_obj->metadata_size = args->len; > > + > > + if (copy_from_user(msm_obj->metadata, > > u64_to_user_ptr(args->value), > > + args->len)) { > > + msm_obj->metadata_size = 0; > > + ret = -EFAULT; > > + } > > + > > + msm_gem_unlock(obj); > > + > > + break; > > + case MSM_INFO_GET_METADATA: > > + if (!args->value) { > > + /* > > + * Querying the size is inherently racey, but > > + * EXT_external_objects expects the app to confirm > > + * via device and driver UUIDs that the exporter and > > + * importer versions match. All we can do from the > > + * kernel side is check the length under obj lock > > + * when userspace tries to retrieve the metadata > > + */ > > + args->len = msm_obj->metadata_size; > > + break; > > + } > > + > > + ret = msm_gem_lock_interruptible(obj); > > + if (ret) > > + break; > > + > > + if (args->len < msm_obj->metadata_size) { > > + ret = -ETOOSMALL; > > + } else if (copy_to_user(u64_to_user_ptr(args->value), > > + msm_obj->metadata, args->len)) { > > + ret = -EFAULT; > > + } > > Doesn't checkpwatch warn here about extra curly brackets? It might.. it is one of the many checkpatch warnings that I dutifully ignore ;-) BR, -R > > + > > + msm_gem_unlock(obj); > > + > > break; > > } > > > > diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h > > index 7f34263048a3..8d414b072c29 100644 > > --- a/drivers/gpu/drm/msm/msm_gem.h > > +++ b/drivers/gpu/drm/msm/msm_gem.h > > @@ -109,6 +109,10 @@ struct msm_gem_object { > > > > char name[32]; /* Identifier to print for the debugfs files */ > > > > + /* userspace metadata backchannel */ > > + void *metadata; > > + u32 metadata_size; > > + > > /** > > * pin_count: Number of times the pages are pinned > > * > > diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h > > index 6c34272a13fd..6f2a7ad04aa4 100644 > > --- a/include/uapi/drm/msm_drm.h > > +++ b/include/uapi/drm/msm_drm.h > > @@ -139,6 +139,8 @@ struct drm_msm_gem_new { > > #define MSM_INFO_GET_NAME 0x03 /* get debug name, returned by > > pointer */ > > #define MSM_INFO_SET_IOVA 0x04 /* set the iova, passed by value */ > > #define MSM_INFO_GET_FLAGS 0x05 /* get the MSM_BO_x flags */ > > +#define MSM_INFO_SET_METADATA 0x06 /* set userspace metadata */ > > +#define MSM_INFO_GET_METADATA 0x07 /* get userspace metadata */ > > > > struct drm_msm_gem_info { > > __u32 handle; /* in */ > > -- > > 2.41.0 > > > > > -- > With best wishes > Dmitry
