From 847afd7bd5607ca974e562d7b2b8f800c4594fe6 Mon Sep 17 00:00:00 2001 From: Jeya R Date: Thu, 23 Sep 2021 14:07:52 +0530 Subject: [PATCH] misc: fastrpc: copy to user only for non-DMA-BUF heap buffers fastrpc_put_args is copying all the output buffers to user. For large number of output context buffers, this might cause performance degradation. Copying is not needed for DMA-BUF heap buffers. Signed-off-by: Jeya R Link: https://lore.kernel.org/r/1632386272-18139-1-git-send-email-jeyr@codeaurora.org Signed-off-by: Greg Kroah-Hartman --- drivers/misc/fastrpc.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index bd7811e3f7619..e0d0c894c5fde 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -890,15 +890,17 @@ static int fastrpc_put_args(struct fastrpc_invoke_ctx *ctx, inbufs = REMOTE_SCALARS_INBUFS(ctx->sc); for (i = inbufs; i < ctx->nbufs; ++i) { - void *src = (void *)(uintptr_t)rpra[i].pv; - void *dst = (void *)(uintptr_t)ctx->args[i].ptr; - u64 len = rpra[i].len; + if (!ctx->maps[i]) { + void *src = (void *)(uintptr_t)rpra[i].pv; + void *dst = (void *)(uintptr_t)ctx->args[i].ptr; + u64 len = rpra[i].len; - if (!kernel) { - if (copy_to_user((void __user *)dst, src, len)) - return -EFAULT; - } else { - memcpy(dst, src, len); + if (!kernel) { + if (copy_to_user((void __user *)dst, src, len)) + return -EFAULT; + } else { + memcpy(dst, src, len); + } } } -- 2.30.2