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authorYanteng Si <siyanteng@loongson.cn>2023-05-10 13:21:46 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2023-05-10 20:19:20 +0300
commite6232180e524e11205d285bb27045bf2c19db265 (patch)
treebc4f1e502a949b9fa77b5d3baba21c42c03f816a /tools/include
parent5d1ac59ff7445e51a0e4958fa39ac8aa23691698 (diff)
downloadlinux-e6232180e524e11205d285bb27045bf2c19db265.tar.xz
tools headers UAPI: Sync the drm/drm.h with the kernel sources
Picking the changes from: 6068771673a38efc ("drm: document DRM_IOCTL_PRIME_HANDLE_TO_FD and PRIME_FD_TO_HANDLE") 61a55f8b1ebcde68 ("drm: document expectations for GETFB2 handles") 158350aae16a4e66 ("drm: document DRM_IOCTL_GEM_CLOSE") Silencing these perf build warnings: Warning: Kernel ABI header at 'tools/include/uapi/drm/drm.h' differs from latest version at 'include/uapi/drm/drm.h' diff -u tools/include/uapi/drm/drm.h include/uapi/drm/drm.h No changes in tooling as these are just C comment documentation changes. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: loongson-kernel@lists.loongnix.cn Link: https://lore.kernel.org/r/7552c61660bf079f2979fdcbcef8e921255f877a.1683712945.git.siyanteng@loongson.cn Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/include')
-rw-r--r--tools/include/uapi/drm/drm.h57
1 files changed, 55 insertions, 2 deletions
diff --git a/tools/include/uapi/drm/drm.h b/tools/include/uapi/drm/drm.h
index 642808520d92..a87bbbbca2d4 100644
--- a/tools/include/uapi/drm/drm.h
+++ b/tools/include/uapi/drm/drm.h
@@ -972,6 +972,19 @@ extern "C" {
#define DRM_IOCTL_GET_STATS DRM_IOR( 0x06, struct drm_stats)
#define DRM_IOCTL_SET_VERSION DRM_IOWR(0x07, struct drm_set_version)
#define DRM_IOCTL_MODESET_CTL DRM_IOW(0x08, struct drm_modeset_ctl)
+/**
+ * DRM_IOCTL_GEM_CLOSE - Close a GEM handle.
+ *
+ * GEM handles are not reference-counted by the kernel. User-space is
+ * responsible for managing their lifetime. For example, if user-space imports
+ * the same memory object twice on the same DRM file description, the same GEM
+ * handle is returned by both imports, and user-space needs to ensure
+ * &DRM_IOCTL_GEM_CLOSE is performed once only. The same situation can happen
+ * when a memory object is allocated, then exported and imported again on the
+ * same DRM file description. The &DRM_IOCTL_MODE_GETFB2 IOCTL is an exception
+ * and always returns fresh new GEM handles even if an existing GEM handle
+ * already refers to the same memory object before the IOCTL is performed.
+ */
#define DRM_IOCTL_GEM_CLOSE DRM_IOW (0x09, struct drm_gem_close)
#define DRM_IOCTL_GEM_FLINK DRM_IOWR(0x0a, struct drm_gem_flink)
#define DRM_IOCTL_GEM_OPEN DRM_IOWR(0x0b, struct drm_gem_open)
@@ -1012,7 +1025,37 @@ extern "C" {
#define DRM_IOCTL_UNLOCK DRM_IOW( 0x2b, struct drm_lock)
#define DRM_IOCTL_FINISH DRM_IOW( 0x2c, struct drm_lock)
+/**
+ * DRM_IOCTL_PRIME_HANDLE_TO_FD - Convert a GEM handle to a DMA-BUF FD.
+ *
+ * User-space sets &drm_prime_handle.handle with the GEM handle to export and
+ * &drm_prime_handle.flags, and gets back a DMA-BUF file descriptor in
+ * &drm_prime_handle.fd.
+ *
+ * The export can fail for any driver-specific reason, e.g. because export is
+ * not supported for this specific GEM handle (but might be for others).
+ *
+ * Support for exporting DMA-BUFs is advertised via &DRM_PRIME_CAP_EXPORT.
+ */
#define DRM_IOCTL_PRIME_HANDLE_TO_FD DRM_IOWR(0x2d, struct drm_prime_handle)
+/**
+ * DRM_IOCTL_PRIME_FD_TO_HANDLE - Convert a DMA-BUF FD to a GEM handle.
+ *
+ * User-space sets &drm_prime_handle.fd with a DMA-BUF file descriptor to
+ * import, and gets back a GEM handle in &drm_prime_handle.handle.
+ * &drm_prime_handle.flags is unused.
+ *
+ * If an existing GEM handle refers to the memory object backing the DMA-BUF,
+ * that GEM handle is returned. Therefore user-space which needs to handle
+ * arbitrary DMA-BUFs must have a user-space lookup data structure to manually
+ * reference-count duplicated GEM handles. For more information see
+ * &DRM_IOCTL_GEM_CLOSE.
+ *
+ * The import can fail for any driver-specific reason, e.g. because import is
+ * only supported for DMA-BUFs allocated on this DRM device.
+ *
+ * Support for importing DMA-BUFs is advertised via &DRM_PRIME_CAP_IMPORT.
+ */
#define DRM_IOCTL_PRIME_FD_TO_HANDLE DRM_IOWR(0x2e, struct drm_prime_handle)
#define DRM_IOCTL_AGP_ACQUIRE DRM_IO( 0x30)
@@ -1104,8 +1147,13 @@ extern "C" {
* struct as the output.
*
* If the client is DRM master or has &CAP_SYS_ADMIN, &drm_mode_fb_cmd2.handles
- * will be filled with GEM buffer handles. Planes are valid until one has a
- * zero handle -- this can be used to compute the number of planes.
+ * will be filled with GEM buffer handles. Fresh new GEM handles are always
+ * returned, even if another GEM handle referring to the same memory object
+ * already exists on the DRM file description. The caller is responsible for
+ * removing the new handles, e.g. via the &DRM_IOCTL_GEM_CLOSE IOCTL. The same
+ * new handle will be returned for multiple planes in case they use the same
+ * memory object. Planes are valid until one has a zero handle -- this can be
+ * used to compute the number of planes.
*
* Otherwise, &drm_mode_fb_cmd2.handles will be zeroed and planes are valid
* until one has a zero &drm_mode_fb_cmd2.pitches.
@@ -1113,6 +1161,11 @@ extern "C" {
* If the framebuffer has a format modifier, &DRM_MODE_FB_MODIFIERS will be set
* in &drm_mode_fb_cmd2.flags and &drm_mode_fb_cmd2.modifier will contain the
* modifier. Otherwise, user-space must ignore &drm_mode_fb_cmd2.modifier.
+ *
+ * To obtain DMA-BUF FDs for each plane without leaking GEM handles, user-space
+ * can export each handle via &DRM_IOCTL_PRIME_HANDLE_TO_FD, then immediately
+ * close each unique handle via &DRM_IOCTL_GEM_CLOSE, making sure to not
+ * double-close handles which are specified multiple times in the array.
*/
#define DRM_IOCTL_MODE_GETFB2 DRM_IOWR(0xCE, struct drm_mode_fb_cmd2)