On Thu, Nov 21, 2024 at 02:17:12PM +0530, Ekansh Gupta wrote:
> Memory intensive applications(which requires more tha 4GB) that wants
> to offload tasks to DSP might have to split the tasks to multiple
> user PD to make the resources available.
>
> For every call to DSP, fastrpc driver passes the process tgid which
> works as an identifier for the DSP to enqueue the tasks to specific PD.
> With current design, if any process opens device node more than once
> and makes PD init request, same tgid will be passed to DSP which will
> be considered a bad request and this will result in failure as the same
> identifier cannot be used for multiple DSP PD.
>
> Assign and pass a client ID to DSP which would be assigned during device
> open and will be dependent on the index of session allocated for the PD.
> This will allow the same process to open the device more than once and
> spawn multiple dynamic PD for ease of processing.
>
> Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
> ---
> drivers/misc/fastrpc.c | 30 ++++++++++++++++--------------
> 1 file changed, 16 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index 74181b8c386b..08f223c95c33 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -39,6 +39,7 @@
> #define FASTRPC_INIT_HANDLE 1
> #define FASTRPC_DSP_UTILITIES_HANDLE 2
> #define FASTRPC_CTXID_MASK (0xFF0)
> +#define FASTRPC_CLIENTID_MASK GENMASK(4, 4)
GENMASK(4,4) is just BIT(4), isn't it?
> #define INIT_FILELEN_MAX (2 * 1024 * 1024)
> #define INIT_FILE_NAMELEN_MAX (128)
> #define FASTRPC_DEVICE_NAME "fastrpc"
> @@ -299,7 +300,7 @@ struct fastrpc_user {
> struct fastrpc_session_ctx *sctx;
> struct fastrpc_buf *init_mem;
>
> - int tgid;
> + int client_id;
> int pd;
> bool is_secure_dev;
> /* Lock for lists */
> @@ -614,7 +615,7 @@ static struct fastrpc_invoke_ctx *fastrpc_context_alloc(
> ctx->sc = sc;
> ctx->retval = -1;
> ctx->pid = current->pid;
> - ctx->tgid = user->tgid;
> + ctx->tgid = user->client_id;
> ctx->cctx = cctx;
> init_completion(&ctx->work);
> INIT_WORK(&ctx->put_work, fastrpc_context_put_wq);
> @@ -1115,7 +1116,7 @@ static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,
> int ret;
>
> cctx = fl->cctx;
> - msg->pid = fl->tgid;
> + msg->pid = fl->client_id;
> msg->tid = current->pid;
>
> if (kernel)
> @@ -1293,7 +1294,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
> }
> }
>
> - inbuf.pgid = fl->tgid;
> + inbuf.pgid = fl->client_id;
> inbuf.namelen = init.namelen;
> inbuf.pageslen = 0;
> fl->pd = USER_PD;
> @@ -1395,7 +1396,7 @@ static int fastrpc_init_create_process(struct fastrpc_user *fl,
> goto err;
> }
>
> - inbuf.pgid = fl->tgid;
> + inbuf.pgid = fl->client_id;
> inbuf.namelen = strlen(current->comm) + 1;
> inbuf.filelen = init.filelen;
> inbuf.pageslen = 1;
> @@ -1469,8 +1470,9 @@ static int fastrpc_init_create_process(struct fastrpc_user *fl,
> }
>
> static struct fastrpc_session_ctx *fastrpc_session_alloc(
> - struct fastrpc_channel_ctx *cctx)
> + struct fastrpc_user *fl)
> {
> + struct fastrpc_channel_ctx *cctx = fl->cctx;
> struct fastrpc_session_ctx *session = NULL;
> unsigned long flags;
> int i;
> @@ -1480,6 +1482,7 @@ static struct fastrpc_session_ctx *fastrpc_session_alloc(
> if (!cctx->session[i].used && cctx->session[i].valid) {
> cctx->session[i].used = true;
> session = &cctx->session[i];
> + fl->client_id = FASTRPC_CLIENTID_MASK | i;
So, it's not a mask, but a flag. Why is it necessary at all? Can you
just pass i? Or i+1?
> break;
> }
> }
> @@ -1504,7 +1507,7 @@ static int fastrpc_release_current_dsp_process(struct fastrpc_user *fl)
> int tgid = 0;
> u32 sc;
>
> - tgid = fl->tgid;
> + tgid = fl->client_id;
> args[0].ptr = (u64)(uintptr_t) &tgid;
> args[0].length = sizeof(tgid);
> args[0].fd = -1;
> @@ -1579,11 +1582,10 @@ static int fastrpc_device_open(struct inode *inode, struct file *filp)
> INIT_LIST_HEAD(&fl->maps);
> INIT_LIST_HEAD(&fl->mmaps);
> INIT_LIST_HEAD(&fl->user);
> - fl->tgid = current->tgid;
> fl->cctx = cctx;
> fl->is_secure_dev = fdevice->secure;
>
> - fl->sctx = fastrpc_session_alloc(cctx);
> + fl->sctx = fastrpc_session_alloc(fl);
> if (!fl->sctx) {
> dev_err(&cctx->rpdev->dev, "No session available\n");
> mutex_destroy(&fl->mutex);
> @@ -1647,7 +1649,7 @@ static int fastrpc_dmabuf_alloc(struct fastrpc_user *fl, char __user *argp)
> static int fastrpc_init_attach(struct fastrpc_user *fl, int pd)
> {
> struct fastrpc_invoke_args args[1];
> - int tgid = fl->tgid;
> + int tgid = fl->client_id;
> u32 sc;
>
> args[0].ptr = (u64)(uintptr_t) &tgid;
> @@ -1803,7 +1805,7 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *
> int err;
> u32 sc;
>
> - req_msg.pgid = fl->tgid;
> + req_msg.pgid = fl->client_id;
> req_msg.size = buf->size;
> req_msg.vaddr = buf->raddr;
>
> @@ -1889,7 +1891,7 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
> return err;
> }
>
> - req_msg.pgid = fl->tgid;
> + req_msg.pgid = fl->client_id;
> req_msg.flags = req.flags;
> req_msg.vaddr = req.vaddrin;
> req_msg.num = sizeof(pages);
> @@ -1978,7 +1980,7 @@ static int fastrpc_req_mem_unmap_impl(struct fastrpc_user *fl, struct fastrpc_me
> return -EINVAL;
> }
>
> - req_msg.pgid = fl->tgid;
> + req_msg.pgid = fl->client_id;
> req_msg.len = map->len;
> req_msg.vaddrin = map->raddr;
> req_msg.fd = map->fd;
> @@ -2031,7 +2033,7 @@ static int fastrpc_req_mem_map(struct fastrpc_user *fl, char __user *argp)
> return err;
> }
>
> - req_msg.pgid = fl->tgid;
> + req_msg.pgid = fl->client_id;
> req_msg.fd = req.fd;
> req_msg.offset = req.offset;
> req_msg.vaddrin = req.vaddrin;
> --
> 2.34.1
>
--
With best wishes
Dmitry
