Hi Zhi, On Thu, Oct 31, 2024 at 01:52:36AM -0700, Zhi Wang wrote: > In order to explain the name clean-ups in GSP RPC routines, a kernel > doc to explain the memory layout and terms is required. > > Add a kernel doc to introduce the GSP RPC. Thanks for adding this -- very much appreciated! > > Signed-off-by: Zhi Wang <zhiw@xxxxxxxxxx> > --- > .../gpu/drm/nouveau/nvkm/subdev/gsp/r535.c | 46 +++++++++++++++++++ > 1 file changed, 46 insertions(+) > > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c > index a4b8381c4e3e..1a07c0191356 100644 > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c I assume the idea is to add this documentation r535 specifically and for it for new firmware versions? > @@ -60,6 +60,52 @@ > #define GSP_MSG_MIN_SIZE GSP_PAGE_SIZE > #define GSP_MSG_MAX_SIZE GSP_PAGE_MIN_SIZE * 16 > > +/** > + * DOC: GSP message queue element We should probably include those DOCs into a Documentation/gpu/nouveau.rst (which would need to be created, now that we add documentation). > + * > + * https://github.com/NVIDIA/open-gpu-kernel-modules/blob/main/src/nvidia/inc/kernel/gpu/gsp/message_queue_priv.h If so, this should not reference the main branch, but rather the corresponding r535 release? > + * > + * The GSP command queue and status queue are message queues for the > + * communication between software and GSP. The software submits the GSP > + * RPC via the GSP command queue, GSP writes the status of the submitted > + * RPC in the status queue. > + * > + * A GSP message queue element consists of three parts: > + * > + * - message element header (struct r535_gsp_msg), which mostly maintains > + * the metadata for queuing the element. > + * > + * - RPC message header (struct nvfw_gsp_rpc), which maintains the info > + * of the RPC. E.g., the RPC function number. > + * > + * - The payload, where the RPC message stays. E.g. the params of a > + * specific RPC function. Some RPC functions also have their headers > + * in the payload. E.g. rm_alloc, rm_control. > + * > + * The memory layout of a GSP message element can be illustrated below: > + * > + * +------------------------+ > + * | Message Element Header | > + * | (r535_gsp_msg) | > + * | | > + * | (r535_gsp_msg.data) | > + * | | | > + * |----------V-------------| > + * | GSP RPC Header | > + * | (nvfw_gsp_rpc) | > + * | | > + * | (nvfw_gsp_rpc.data) | > + * | | | > + * |----------V-------------| > + * | | > + * | Payload | > + * | | > + * | header(optional) | > + * | params | > + * +------------------------+ > + * > + */ > + > struct r535_gsp_msg { > u8 auth_tag_buffer[16]; > u8 aad_buffer[16]; > -- > 2.34.1 >
