[SRU][J:linux-bluefield][PATCH v1 1/1] UBUNTU: SAUCE: mlx-bootctl: support icm carveout eeprom region read/write

[Asmaa Mnebhi]

BugLink: https://bugs.launchpad.net/bugs/1995296

The BlueField-3 ICM carveout feature will enable NIC FW to bypass the SMMU block
to access DRAM memory. The amount of memory accessible by FW will be controlled by ARM.
This patch enables setting the size of the large ICM carveout from
userspace. The max size is 1TB, has a granularity of 128MB and will be passed
and printed in hex. The size unit is MB.

Signed-off-by: Asmaa Mnebhi <asmaa at nvidia.com>
---
 drivers/platform/mellanox/mlxbf-bootctl.c | 40 +++++++++++++++++++++++
 drivers/platform/mellanox/mlxbf-bootctl.h |  9 +++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/platform/mellanox/mlxbf-bootctl.c b/drivers/platform/mellanox/mlxbf-bootctl.c
index 2302e1e09c7e..e8877a19dda9 100644
--- a/drivers/platform/mellanox/mlxbf-bootctl.c
+++ b/drivers/platform/mellanox/mlxbf-bootctl.c
@@ -104,6 +104,7 @@ enum {
 
 /* This mutex is used to serialize MFG write and lock operations. */
 static DEFINE_MUTEX(mfg_ops_lock);
+static DEFINE_MUTEX(icm_ops_lock);
 
 #define MLNX_MFG_OOB_MAC_LEN         ETH_ALEN
 #define MLNX_MFG_OPN_VAL_LEN         24
@@ -383,6 +384,43 @@ static ssize_t oob_mac_store(struct device_driver *drv, const char *buf,
 	return res.a0 ? -EPERM : count;
 }
 
+static ssize_t large_icm_show(struct device_driver *drv, char *buf)
+{
+	char icm_str[MAX_ICM_BUFFER_SIZE] = { 0 };
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(MLNX_HANDLE_GET_ICM_INFO, 0, 0, 0, 0,
+		      0, 0, 0, &res);
+	if (res.a0)
+		return -EPERM;
+
+	sprintf(icm_str, "0x%lx", res.a1);
+
+	return snprintf(buf, sizeof(icm_str), "%s", icm_str);
+}
+
+static ssize_t large_icm_store(struct device_driver *drv, const char *buf,
+			     size_t count)
+{
+	struct arm_smccc_res res;
+	unsigned long icm_data;
+	int err;
+
+	err = kstrtoul(buf, 16, &icm_data);
+	if (err)
+		return err;
+
+	if (((icm_data != 0) && (icm_data < 0x80)) ||
+	    (icm_data > 0x100000) || (icm_data % 128))
+		return -EPERM;
+
+	mutex_lock(&icm_ops_lock);
+	arm_smccc_smc(MLNX_HANDLE_SET_ICM_INFO, icm_data, 0, 0, 0, 0, 0, 0, &res);
+	mutex_unlock(&icm_ops_lock);
+
+	return res.a0 ? -EPERM : count;
+}
+
 static ssize_t opn_show(struct device_driver *drv, char *buf)
 {
 	u64 opn_data[MLNX_MFG_VAL_QWORD_CNT(OPN)] = { 0 };
@@ -1170,6 +1208,7 @@ static DRIVER_ATTR_RW(uuid);
 static DRIVER_ATTR_RW(rev);
 static DRIVER_ATTR_WO(mfg_lock);
 static DRIVER_ATTR_RW(rsh_log);
+static DRIVER_ATTR_RW(large_icm);
 
 static struct attribute *mbc_dev_attrs[] = {
 	&driver_attr_post_reset_wdog.attr,
@@ -1187,6 +1226,7 @@ static struct attribute *mbc_dev_attrs[] = {
 	&driver_attr_rev.attr,
 	&driver_attr_mfg_lock.attr,
 	&driver_attr_rsh_log.attr,
+	&driver_attr_large_icm.attr,
 	NULL
 };
 
diff --git a/drivers/platform/mellanox/mlxbf-bootctl.h b/drivers/platform/mellanox/mlxbf-bootctl.h
index 3e9dda829d6d..c70204770af3 100644
--- a/drivers/platform/mellanox/mlxbf-bootctl.h
+++ b/drivers/platform/mellanox/mlxbf-bootctl.h
@@ -95,6 +95,15 @@
 #define MLNX_HANDLE_GET_MFG_INFO    0x8200000F
 #define MLNX_HANDLE_LOCK_MFG_INFO   0x82000011
 
+/*
+ * SMC function IDs to set and get the large ICM carveout size
+ * stored in the eeprom.
+ */
+#define MLNX_HANDLE_SET_ICM_INFO    0x82000012
+#define MLNX_HANDLE_GET_ICM_INFO    0x82000013
+
+#define MAX_ICM_BUFFER_SIZE 10
+
 /* SMC function IDs for SiP Service queries */
 #define MLNX_SIP_SVC_CALL_COUNT		0x8200ff00
 #define MLNX_SIP_SVC_UID		0x8200ff01
-- 
2.30.1