On 7/3/2024 4:12 PM, Dmitry Baryshkov wrote:
> On Wed, Jul 03, 2024 at 12:22:00PM GMT, 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. Allocate and pass an effective
>> pgid to DSP which would be allocated during device open and will have
>> a lifetime till the device is closed. This will allow the same process
>> to open the device more than once and spawn multiple dynamic PD for
>> ease of processing.
> Consider adding line breaks to split the text into paragraphs to make it
> easier to read.
>
> The patch also raises the question whether the identifier should be
> unique per DSP or per the channel.
I'll update the commit text with more clear information.
>> Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
>> ---
>> drivers/misc/fastrpc.c | 48 ++++++++++++++++++++++++++++++++++--------
>> 1 file changed, 39 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
>> index 5204fda51da3..7250e30aa93f 100644
>> --- a/drivers/misc/fastrpc.c
>> +++ b/drivers/misc/fastrpc.c
>> @@ -105,6 +105,10 @@
>>
>> #define miscdev_to_fdevice(d) container_of(d, struct fastrpc_device, miscdev)
>>
>> +#define MAX_DSP_PD 64
>> +#define MIN_FRPC_PGID 1000
>> +#define MAX_FRPC_PGID (MIN_FRPC_PGID + MAX_DSP_PD)
>> +
>> static const char *domains[FASTRPC_DEV_MAX] = { "adsp", "mdsp",
>> "sdsp", "cdsp"};
>> struct fastrpc_phy_page {
>> @@ -268,6 +272,7 @@ struct fastrpc_channel_ctx {
>> struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
>> spinlock_t lock;
>> struct idr ctx_idr;
>> + struct ida dsp_pgid_ida;
>> struct list_head users;
>> struct kref refcount;
>> /* Flag if dsp attributes are cached */
>> @@ -299,6 +304,7 @@ struct fastrpc_user {
>> struct fastrpc_buf *init_mem;
>>
>> int tgid;
> Is it still used? What for?
I don't see any usage as of now, this can be removed.
>
>> + int dsp_pgid;
> unsigned int
planning to keep it u32 as the range is going to be from 1000-1064
>
>> int pd;
>> bool is_secure_dev;
>> /* Lock for lists */
>> @@ -462,6 +468,7 @@ static void fastrpc_channel_ctx_free(struct kref *ref)
>> struct fastrpc_channel_ctx *cctx;
>>
>> cctx = container_of(ref, struct fastrpc_channel_ctx, refcount);
>> + ida_destroy(&cctx->dsp_pgid_ida);
>>
>> kfree(cctx);
>> }
>> @@ -1114,7 +1121,7 @@ static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,
>> int ret;
>>
>> cctx = fl->cctx;
>> - msg->pid = fl->tgid;
>> + msg->pid = fl->dsp_pgid;
>> msg->tid = current->pid;
>>
>> if (kernel)
>> @@ -1292,7 +1299,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
>> }
>> }
>>
>> - inbuf.pgid = fl->tgid;
>> + inbuf.pgid = fl->dsp_pgid;
>> inbuf.namelen = init.namelen;
>> inbuf.pageslen = 0;
>> fl->pd = USER_PD;
>> @@ -1394,7 +1401,7 @@ static int fastrpc_init_create_process(struct fastrpc_user *fl,
>> goto err;
>> }
>>
>> - inbuf.pgid = fl->tgid;
>> + inbuf.pgid = fl->dsp_pgid;
>> inbuf.namelen = strlen(current->comm) + 1;
>> inbuf.filelen = init.filelen;
>> inbuf.pageslen = 1;
>> @@ -1503,7 +1510,7 @@ static int fastrpc_release_current_dsp_process(struct fastrpc_user *fl)
>> int tgid = 0;
>> u32 sc;
>>
>> - tgid = fl->tgid;
>> + tgid = fl->dsp_pgid;
>> args[0].ptr = (u64)(uintptr_t) &tgid;
>> args[0].length = sizeof(tgid);
>> args[0].fd = -1;
>> @@ -1528,6 +1535,9 @@ static int fastrpc_device_release(struct inode *inode, struct file *file)
>> list_del(&fl->user);
>> spin_unlock_irqrestore(&cctx->lock, flags);
>>
>> + if (fl->dsp_pgid != -1)
> Why -1? On which path can it be left uninitialized?
in case ida allocation fails, I was setting this to -1 but now I don't see any reason for
this check as if ida alloc fails, that will result in open() failure.
>
>> + ida_free(&cctx->dsp_pgid_ida, fl->dsp_pgid);
>> +
>> if (fl->init_mem)
>> fastrpc_buf_free(fl->init_mem);
>>
>> @@ -1554,6 +1564,19 @@ static int fastrpc_device_release(struct inode *inode, struct file *file)
>> return 0;
>> }
>>
>> +static int fastrpc_pgid_alloc(struct fastrpc_channel_ctx *cctx)
>> +{
>> + int ret = -1;
> There is no need to init it, is there?
no, I'll remove this.
>
>> +
>> + /* allocate unique id between MIN_FRPC_PGID and MAX_FRPC_PGID */
>> + ret = ida_alloc_range(&cctx->dsp_pgid_ida, MIN_FRPC_PGID,
>> + MAX_FRPC_PGID, GFP_ATOMIC);
>> + if (ret < 0)
>> + return -1;
> Don't throw away error codes. Pass them as is.
Ack.
>
>> +
>> + return ret;
>> +}
>> +
>> static int fastrpc_device_open(struct inode *inode, struct file *filp)
>> {
>> struct fastrpc_channel_ctx *cctx;
>> @@ -1582,6 +1605,12 @@ static int fastrpc_device_open(struct inode *inode, struct file *filp)
>> fl->cctx = cctx;
>> fl->is_secure_dev = fdevice->secure;
>>
>> + fl->dsp_pgid = fastrpc_pgid_alloc(cctx);
>> + if (fl->dsp_pgid == -1) {
>> + dev_dbg(&cctx->rpdev->dev, "too many fastrpc clients, max %u allowed\n", MAX_DSP_PD);
>> + return -EUSERS;
> Huh? Please return the error code that ida_alloc() returned;
Ack.
>
>> + }
>> +
>> fl->sctx = fastrpc_session_alloc(cctx);
>> if (!fl->sctx) {
>> dev_err(&cctx->rpdev->dev, "No session available\n");
>> @@ -1646,7 +1675,7 @@ 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->dsp_pgid;
> unsigned?
will update this. Thanks.
--Ekansh
>
>> u32 sc;
>>
>> args[0].ptr = (u64)(uintptr_t) &tgid;
>> @@ -1802,7 +1831,7 @@ 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->dsp_pgid;
>> req_msg.size = buf->size;
>> req_msg.vaddr = buf->raddr;
>>
>> @@ -1888,7 +1917,7 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
>> return err;
>> }
>>
>> - req_msg.pgid = fl->tgid;
>> + req_msg.pgid = fl->dsp_pgid;
>> req_msg.flags = req.flags;
>> req_msg.vaddr = req.vaddrin;
>> req_msg.num = sizeof(pages);
>> @@ -1978,7 +2007,7 @@ 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->dsp_pgid;
>> req_msg.len = map->len;
>> req_msg.vaddrin = map->raddr;
>> req_msg.fd = map->fd;
>> @@ -2031,7 +2060,7 @@ static int fastrpc_req_mem_map(struct fastrpc_user *fl, char __user *argp)
>> return err;
>> }
>>
>> - req_msg.pgid = fl->tgid;
>> + req_msg.pgid = fl->dsp_pgid;
>> req_msg.fd = req.fd;
>> req_msg.offset = req.offset;
>> req_msg.vaddrin = req.vaddrin;
>> @@ -2375,6 +2404,7 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
>> INIT_LIST_HEAD(&data->invoke_interrupted_mmaps);
>> spin_lock_init(&data->lock);
>> idr_init(&data->ctx_idr);
>> + ida_init(&data->dsp_pgid_ida);
>> data->domain_id = domain_id;
>> data->rpdev = rpdev;
>>
>> --
>> 2.34.1
>>
