This patch add support for passing shmem channel address as parameters
in smc/hvc call. The address is split into 4KB-page and offset.
This patch is useful when multiple scmi instances are using same smc-id
and firmware needs to distinguish among the instances.
Signed-off-by: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
---
drivers/firmware/arm_scmi/driver.c | 1 +
drivers/firmware/arm_scmi/smc.c | 14 +++++++++++++-
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index e7d97b59963b..b5957cc12fee 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2914,6 +2914,7 @@ static const struct of_device_id scmi_of_match[] = {
#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
{ .compatible = "arm,scmi-smc", .data = &scmi_smc_desc},
+ { .compatible = "arm,scmi-smc-param", .data = &scmi_smc_desc},
#endif
#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO
{ .compatible = "arm,scmi-virtio", .data = &scmi_virtio_desc},
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index 93272e4bbd12..71e080b70df5 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -20,6 +20,11 @@
#include "common.h"
+#define SHMEM_SHIFT 12
+#define SHMEM_SIZE (_AC(1, UL) << SHMEM_SHIFT)
+#define SHMEM_PAGE(x) ((unsigned long)((x) >> SHMEM_SHIFT))
+#define SHMEM_OFFSET(x) ((x) & (SHMEM_SIZE - 1))
+
/**
* struct scmi_smc - Structure representing a SCMI smc transport
*
@@ -30,6 +35,7 @@
* @inflight: Atomic flag to protect access to Tx/Rx shared memory area.
* Used when operating in atomic mode.
* @func_id: smc/hvc call function id
+ * @param: physical address of the shmem channel
*/
struct scmi_smc {
@@ -40,6 +46,7 @@ struct scmi_smc {
#define INFLIGHT_NONE MSG_TOKEN_MAX
atomic_t inflight;
u32 func_id;
+ phys_addr_t param;
};
static irqreturn_t smc_msg_done_isr(int irq, void *data)
@@ -137,6 +144,8 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
if (ret < 0)
return ret;
+ if (of_device_is_compatible(dev->of_node, "arm,scmi-smc-param"))
+ scmi_info->param = res.start;
/*
* If there is an interrupt named "a2p", then the service and
* completion of a message is signaled by an interrupt rather than by
@@ -179,6 +188,8 @@ static int smc_send_message(struct scmi_chan_info *cinfo,
{
struct scmi_smc *scmi_info = cinfo->transport_info;
struct arm_smccc_res res;
+ unsigned long page = SHMEM_PAGE(scmi_info->param);
+ unsigned long offset = SHMEM_OFFSET(scmi_info->param);
/*
* Channel will be released only once response has been
@@ -188,7 +199,8 @@ static int smc_send_message(struct scmi_chan_info *cinfo,
shmem_tx_prepare(scmi_info->shmem, xfer, cinfo);
- arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res);
+ arm_smccc_1_1_invoke(scmi_info->func_id, page, offset, 0, 0, 0, 0, 0,
+ &res);
/* Only SMCCC_RET_NOT_SUPPORTED is valid error code */
if (res.a0) {
