Commit 9902cb99 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm/gem: Add metadata 



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: default avatarRob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/566157/
parent d1912f69

drivers/gpu/drm/msm/msm_drv.c

+91 −1
Original line number Diff line number Diff line
@@ -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	11

#define MSM_VERSION_MINOR	12

#define MSM_VERSION_PATCHLEVEL	0



static void msm_deinit_vram(struct drm_device *ddev);
@@ -546,6 +547,85 @@ 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)

{
@@ -568,6 +648,8 @@ 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;
@@ -630,6 +712,14 @@ 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);

drivers/gpu/drm/msm/msm_gem.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

}

drivers/gpu/drm/msm/msm_gem.h

+4 −0
Original line number Diff line number Diff line
@@ -108,6 +108,10 @@ 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

	 *

include/uapi/drm/msm_drm.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */