[PATCH v6 07/11] misc: amd-sbi: Add support for mailbox error codes
From: Akshay Gupta
Date: Mon Mar 24 2025 - 11:01:30 EST
APML mailbox protocol returns additional error codes written by
SMU firmware in the out-bound register 0x37. These errors include,
invalid core, message not supported over platform and
others. This additional error codes can be used to provide more
details to user space.
Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@xxxxxxx>
Signed-off-by: Akshay Gupta <akshay.gupta@xxxxxxx>
---
Changes since v5:
- Patch rebased
Changes since v4:
- Previously patch 5
- Fix Documentation warning
Changes since v3:
- update ioctl comment description
Changes since v1:
- bifurcated from previous patch 5
drivers/misc/amd-sbi/rmi-core.c | 12 +++++++++++-
include/uapi/misc/amd-apml.h | 5 +++++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/amd-sbi/rmi-core.c b/drivers/misc/amd-sbi/rmi-core.c
index eafdd2799034..332cb03e8326 100644
--- a/drivers/misc/amd-sbi/rmi-core.c
+++ b/drivers/misc/amd-sbi/rmi-core.c
@@ -25,13 +25,15 @@
int rmi_mailbox_xfer(struct sbrmi_data *data,
struct apml_message *msg)
{
- unsigned int bytes;
+ unsigned int bytes, ec;
int i, ret;
int sw_status;
u8 byte;
mutex_lock(&data->lock);
+ msg->fw_ret_code = 0;
+
/* Indicate firmware a command is to be serviced */
ret = regmap_write(data->regmap, SBRMI_INBNDMSG7, START_CMD);
if (ret < 0)
@@ -72,6 +74,9 @@ int rmi_mailbox_xfer(struct sbrmi_data *data,
if (ret)
goto exit_unlock;
+ ret = regmap_read(data->regmap, SBRMI_OUTBNDMSG7, &ec);
+ if (ret || ec)
+ goto exit_clear_alert;
/*
* For a read operation, the initiator (BMC) reads the firmware
* response Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1]
@@ -87,12 +92,17 @@ int rmi_mailbox_xfer(struct sbrmi_data *data,
}
}
+exit_clear_alert:
/*
* BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the
* ALERT to initiator
*/
ret = regmap_write(data->regmap, SBRMI_STATUS,
sw_status | SW_ALERT_MASK);
+ if (ec) {
+ ret = -EPROTOTYPE;
+ msg->fw_ret_code = ec;
+ }
exit_unlock:
mutex_unlock(&data->lock);
return ret;
diff --git a/include/uapi/misc/amd-apml.h b/include/uapi/misc/amd-apml.h
index 451cab135a08..d0c548e34150 100644
--- a/include/uapi/misc/amd-apml.h
+++ b/include/uapi/misc/amd-apml.h
@@ -36,6 +36,10 @@ struct apml_message {
* Mailbox Messages: 0x0 ... 0x999
*/
__u32 cmd;
+ /*
+ * Error code is returned in case of soft mailbox
+ */
+ __u32 fw_ret_code;
};
/*
@@ -58,6 +62,7 @@ struct apml_message {
* The APML RMI module checks whether the cmd is
* - Mailbox message read/write(0x0~0x999)
* - returning "-EFAULT" if none of the above
+ * "-EPROTOTYPE" error is returned to provide additional error details
*/
#define SBRMI_IOCTL_CMD _IOWR(SB_BASE_IOCTL_NR, 0, struct apml_message)
--
2.25.1