[PATCH] firmware: scmi: Replace memcpy_from/toio() by memcpy() in scmi_read/write_resp_from_smt()

[Mark Kettenis]

> From: Patrice Chotard <patrice.chotard at foss.st.com>
> Date: Wed, 24 Feb 2021 13:47:55 +0100
> 
> To avoid "synchronous abort" in AARCH64 in case the "from" address
> is not aligned, replace memcpy_toio() and memcpy_fromio() by memcpy().
> 
> Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
> Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
> ---
> 
>  drivers/firmware/scmi/smt.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

This doesnt really make sense.  There is no guarantee that memcpy()
doesn't do an unaligned load or store either.

Unaligned loads and stores from/to normal memory should just work on
arm64, and memcpy_toio() and memcpy_fromio() make sure they don't do
unaligned loads and stores from/to "IO" memory (in this case the
shared memory buffer).

> diff --git a/drivers/firmware/scmi/smt.c b/drivers/firmware/scmi/smt.c
> index d25478796a..b001163b62 100644
> --- a/drivers/firmware/scmi/smt.c
> +++ b/drivers/firmware/scmi/smt.c
> @@ -93,7 +93,7 @@ int scmi_write_msg_to_smt(struct udevice *dev, struct scmi_smt *smt,
>  			  SMT_HEADER_PROTOCOL_ID(msg->protocol_id) |
>  			  SMT_HEADER_MESSAGE_ID(msg->message_id);
>  
> -	memcpy_toio(hdr->msg_payload, msg->in_msg, msg->in_msg_sz);
> +	memcpy(hdr->msg_payload, msg->in_msg, msg->in_msg_sz);
>  
>  	return 0;
>  }
> @@ -124,7 +124,7 @@ int scmi_read_resp_from_smt(struct udevice *dev, struct scmi_smt *smt,
>  
>  	/* Get the data */
>  	msg->out_msg_sz = hdr->length - sizeof(hdr->msg_header);
> -	memcpy_fromio(msg->out_msg, hdr->msg_payload, msg->out_msg_sz);
> +	memcpy(msg->out_msg, hdr->msg_payload, msg->out_msg_sz);
>  
>  	return 0;
>  }
> -- 
> 2.17.1
> 
>