[PATCH v4 6/6] fpga: m10bmc-sec: add max10 get_hw_errinfo callback func

[Russ Weight]

Extend the MAX10 BMC Secure Update driver to include
a function that returns 64 bits of additional HW specific
data for errors that require additional information.
This callback function enables the hw_errinfo sysfs
node in the Intel Security Manager class driver.

Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
---
v4:
  - No change
v3:
  - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
  - Changed "MAX10 BMC Secure Engine driver" to "MAX10 BMC Secure Update
    driver"
v2:
  - Implemented HW_ERRINFO_POISON for m10bmc_sec_hw_errinfo() to
    ensure that corresponding bits are set to 1 if we are unable
    to read the doorbell or auth_result registers.
  - Added m10bmc_ prefix to functions in m10bmc_iops structure
---
 drivers/fpga/intel-m10-bmc-secure.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/fpga/intel-m10-bmc-secure.c b/drivers/fpga/intel-m10-bmc-secure.c
index 0f3321fbd987..b912d69044d9 100644
--- a/drivers/fpga/intel-m10-bmc-secure.c
+++ b/drivers/fpga/intel-m10-bmc-secure.c
@@ -472,11 +472,36 @@ static enum fpga_sec_err m10bmc_sec_cancel(struct fpga_sec_mgr *smgr)
 	return ret ? FPGA_SEC_ERR_RW_ERROR : FPGA_SEC_ERR_NONE;
 }
 
+#define HW_ERRINFO_POISON	GENMASK(31, 0)
+static u64 m10bmc_sec_hw_errinfo(struct fpga_sec_mgr *smgr)
+{
+	struct m10bmc_sec *sec = smgr->priv;
+	u32 doorbell, auth_result;
+
+	switch (smgr->err_code) {
+	case FPGA_SEC_ERR_HW_ERROR:
+	case FPGA_SEC_ERR_TIMEOUT:
+	case FPGA_SEC_ERR_BUSY:
+	case FPGA_SEC_ERR_WEAROUT:
+		if (m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, &doorbell))
+			doorbell = HW_ERRINFO_POISON;
+
+		if (m10bmc_sys_read(sec->m10bmc, M10BMC_AUTH_RESULT,
+				    &auth_result))
+			auth_result = HW_ERRINFO_POISON;
+
+		return (u64)doorbell << 32 | (u64)auth_result;
+	default:
+		return 0;
+	}
+}
+
 static const struct fpga_sec_mgr_ops m10bmc_sops = {
 	.prepare = m10bmc_sec_prepare,
 	.write_blk = m10bmc_sec_write_blk,
 	.poll_complete = m10bmc_sec_poll_complete,
 	.cancel = m10bmc_sec_cancel,
+	.get_hw_errinfo = m10bmc_sec_hw_errinfo,
 };
 
 static int m10bmc_secure_probe(struct platform_device *pdev)
-- 
2.25.1