From: Rob Clark <robdclark@xxxxxxxxxxxx>
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.
v2: add missing metadata kfree
v3: Rework to move copy_from/to_user out from under gem obj lock
to avoid angering lockdep about deadlocks against fs-reclaim
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
Note, I dropped Dmitry's r-b on this version because it was a bit of
a re-write of the original patch.
drivers/gpu/drm/msm/msm_drv.c | 92 ++++++++++++++++++++++++++++++++++-
drivers/gpu/drm/msm/msm_gem.c | 1 +
drivers/gpu/drm/msm/msm_gem.h | 4 ++
include/uapi/drm/msm_drm.h | 2 +
4 files changed, 98 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 781db689fb16..c05c27a70c34 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -49,9 +49,10 @@
* - 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 11
+#define MSM_VERSION_MINOR 12
#define MSM_VERSION_PATCHLEVEL 0
static void msm_deinit_vram(struct drm_device *ddev);
@@ -822,6 +823,85 @@ static int msm_ioctl_gem_info_set_iova(struct drm_device *dev,
return msm_gem_set_iova(obj, ctx->aspace, iova);
}
+static int msm_ioctl_gem_info_set_metadata(struct drm_gem_object *obj,
+ __user void *metadata,
+ u32 metadata_size)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ void *buf;
+ int ret;
+
+ /* Impose a moderate upper bound on metadata size: */
+ if (metadata_size > 128) {
+ return -EOVERFLOW;
+ }
+
+ /* Use a temporary buf to keep copy_from_user() outside of gem obj lock: */
+ buf = memdup_user(metadata, metadata_size);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+
+ ret = msm_gem_lock_interruptible(obj);
+ if (ret)
+ goto out;
+
+ msm_obj->metadata =
+ krealloc(msm_obj->metadata, metadata_size, GFP_KERNEL);
+ msm_obj->metadata_size = metadata_size;
+ memcpy(msm_obj->metadata, buf, metadata_size);
+
+ msm_gem_unlock(obj);
+
+out:
+ kfree(buf);
+
+ return ret;
+}
+
+static int msm_ioctl_gem_info_get_metadata(struct drm_gem_object *obj,
+ __user void *metadata,
+ u32 *metadata_size)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ void *buf;
+ int ret, len;
+
+ if (!metadata) {
+ /*
+ * 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
+ */
+ *metadata_size = msm_obj->metadata_size;
+ return 0;
+ }
+
+ ret = msm_gem_lock_interruptible(obj);
+ if (ret)
+ return ret;
+
+ /* Avoid copy_to_user() under gem obj lock: */
+ len = msm_obj->metadata_size;
+ buf = kmemdup(msm_obj->metadata, len, GFP_KERNEL);
+
+ msm_gem_unlock(obj);
+
+ if (*metadata_size < len) {
+ ret = -ETOOSMALL;
+ } else if (copy_to_user(metadata, buf, len)) {
+ ret = -EFAULT;
+ } else {
+ *metadata_size = len;
+ }
+
+ kfree(buf);
+
+ return 0;
+}
+
static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
struct drm_file *file)
{
@@ -844,6 +924,8 @@ 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;
@@ -906,6 +988,14 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
ret = -EFAULT;
}
break;
+ case MSM_INFO_SET_METADATA:
+ ret = msm_ioctl_gem_info_set_metadata(
+ obj, u64_to_user_ptr(args->value), args->len);
+ break;
+ case MSM_INFO_GET_METADATA:
+ ret = msm_ioctl_gem_info_get_metadata(
+ obj, u64_to_user_ptr(args->value), &args->len);
+ break;
}
drm_gem_object_put(obj);
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 1113e6b2ec8e..175ee4ab8a6f 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -1058,6 +1058,7 @@ static void msm_gem_free_object(struct drm_gem_object *obj)
drm_gem_object_release(obj);
+ kfree(msm_obj->metadata);
kfree(msm_obj);
}
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
