> Subject: [PATCH 1/4] firmware: arm_scmi: Make mutex channel specific
>
> In order to support multiple SMC/HVC transport channels with associated
> shared memory, it is better to maintain the mutex per channel instead of
> existing global one.
>
> Move the smc_mutex into the scmi_smc structure and also rename it to
> shmem_lock which is more appropriate for it's use.
>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> drivers/firmware/arm_scmi/smc.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/firmware/arm_scmi/smc.c
> b/drivers/firmware/arm_scmi/smc.c index 336168e40f49..6dc8a88cc91b
> 100644
> --- a/drivers/firmware/arm_scmi/smc.c
> +++ b/drivers/firmware/arm_scmi/smc.c
> @@ -27,11 +27,10 @@
> struct scmi_smc {
> struct scmi_chan_info *cinfo;
> struct scmi_shared_mem __iomem *shmem;
> + struct mutex shmem_lock;
> u32 func_id;
> };
>
> -static DEFINE_MUTEX(smc_mutex);
> -
> static bool smc_chan_available(struct device *dev, int idx) {
> return true;
> @@ -78,6 +77,7 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo,
> struct device *dev,
>
> scmi_info->func_id = func_id;
> scmi_info->cinfo = cinfo;
> + mutex_init(&scmi_info->shmem_lock);
> cinfo->transport_info = scmi_info;
>
> return 0;
> @@ -102,14 +102,14 @@ static int smc_send_message(struct
> scmi_chan_info *cinfo,
> struct scmi_smc *scmi_info = cinfo->transport_info;
> struct arm_smccc_res res;
>
> - mutex_lock(&smc_mutex);
> + mutex_lock(&scmi_info->shmem_lock);
>
> shmem_tx_prepare(scmi_info->shmem, xfer);
>
> arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res);
> scmi_rx_callback(scmi_info->cinfo,
> shmem_read_header(scmi_info->shmem));
>
> - mutex_unlock(&smc_mutex);
> + mutex_unlock(&scmi_info->shmem_lock);
>
> return res.a0;
> }
> --
> 2.17.1
