[PATCH v1] misc: fastrpc: Free DMA handles for RPC calls with no arguments

From: Ekansh Gupta
Date: Thu Aug 31 2023 - 02:25:45 EST


The FDs for DMA handles to be freed is updated in fdlist by DSP over
a remote call. This holds true even for remote calls with no
arguments. To handle this, get_args and put_args are needed to
be called for remote calls with no arguments also as fdlist
is allocated in get_args and FDs updated in fdlist is freed
in put_args.

Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
---
drivers/misc/fastrpc.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 9666d28..e6df66e 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1153,11 +1153,9 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
if (IS_ERR(ctx))
return PTR_ERR(ctx);

- if (ctx->nscalars) {
- err = fastrpc_get_args(kernel, ctx);
- if (err)
- goto bail;
- }
+ err = fastrpc_get_args(kernel, ctx);
+ if (err)
+ goto bail;

/* make sure that all CPU memory writes are seen by DSP */
dma_wmb();
@@ -1181,14 +1179,12 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl, u32 kernel,
if (err)
goto bail;

- if (ctx->nscalars) {
- /* make sure that all memory writes by DSP are seen by CPU */
- dma_rmb();
- /* populate all the output buffers with results */
- err = fastrpc_put_args(ctx, kernel);
- if (err)
- goto bail;
- }
+ /* make sure that all memory writes by DSP are seen by CPU */
+ dma_rmb();
+ /* populate all the output buffers with results */
+ err = fastrpc_put_args(ctx, kernel);
+ if (err)
+ goto bail;

bail:
if (err != -ERESTARTSYS && err != -ETIMEDOUT) {
--
2.7.4