On 26 4月 22 12:50:50, Arnd Bergmann wrote: > On Tue, Apr 26, 2022 at 8:31 AM Christian König > <christian.koenig@xxxxxxx> wrote: > > Am 26.04.22 um 08:08 schrieb Cai Huoqing: > > > The NVIDIA Deep Learning Accelerator (NVDLA) is an open source IP > > > which is integrated into NVIDIA Jetson AGX Xavier, > > > so add UAPI of this driver. > > > > > > Signed-off-by: Cai Huoqing <cai.huoqing@xxxxxxxxx> > > I saw the reply but no the original mail, so I'll comment here Hi, thanks for your reply The patches here: https://lore.kernel.org/lkml/20220426060808.78225-3-cai.huoqing@xxxxxxxxx/ > > > > + > > > +#if !defined(__KERNEL__) > > > +#define __user > > > +#endif > > This is done in the 'make headers_install' step, no need to define it > separately. > > > > +#define NVDLA_NO_TIMEOUT (0xffffffff) > > > + __u32 timeout; > > > > What format does that timeout value have? > > > > In general it is best practice to have absolute 64bit nanosecond > > timeouts (to be used with ktime inside the kernel) so that restarting > > interrupted IOCTLs works smooth. > > When using absolute values, one also needs to decide whether this should be > realtime, monotonic or boottime and document the decision. > > > > > + * struct nvdla_submit_args structure for task submit > > > + * > > > + * @tasks pointer to array of struct nvdla_ioctl_submit_task > > > + * @num_tasks number of entries in tasks > > > + * @flags flags for task submit, no flags defined yet > > > + * @version version of task structure > > > + * > > > + */ > > > +struct nvdla_submit_args { > > > + __u64 tasks; > > > + __u16 num_tasks; > > > +#define NVDLA_MAX_TASKS_PER_SUBMIT 24 > > > +#define NVDLA_SUBMIT_FLAGS_ATOMIC (1 << 0) > > > > Well that "no flags defined yet" from the comment above is probably > > outdated :) > > > > + __u16 flags; > > > + __u32 version; > > > +}; > > Versioned interfaces are usually a bad idea. If you introduce an ioctl command, > it should generally keep working. If you ever need to change the interface, just > use a new command number for the new version. > > > > +/** > > > + * struct nvdla_gem_create_args for allocating DMA buffer through GEM > > > + * > > > + * @handle handle updated by kernel after allocation > > > + * @flags implementation specific flags > > > + * @size size of buffer to allocate > > > + */ > > > +struct nvdla_gem_create_args { > > > + __u32 handle; > > > + __u32 flags; > > > + __u64 size; > > > +}; > > > + > > > +/** > > > + * struct nvdla_gem_map_offset_args for mapping DMA buffer > > > + * > > > + * @handle handle of the buffer > > > + * @reserved reserved for padding > > > + * @offset offset updated by kernel after mapping > > > + */ > > > +struct nvdla_gem_map_offset_args { > > > + __u32 handle; > > > + __u32 reserved; > > > + __u64 offset; > > > +}; > > > + > > > +#define DRM_NVDLA_SUBMIT 0x00 > > > +#define DRM_NVDLA_GEM_CREATE 0x01 > > > +#define DRM_NVDLA_GEM_MMAP 0x02 > > Is this an actual mmap() call, or something that needs to be done before the > mmap()? Is the 'handle' a file descriptor or some internal number? It's an gem object mmap which calls drm_gem_dumb_map_offset() inside and the handle is gem object handle. Thanks, Cai > > Arnd
