[PATCH v1 1/2] mlxbf-bootctl: Support the large icmc write/read

From: Asmaa Mnebhi
Date: Wed Aug 09 2023 - 10:15:43 EST


Enable reading and writing the size of the memory region associated
with the large ICM carveout.
The max size of the large ICM carveout 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@xxxxxxxxxx>
---
drivers/platform/mellanox/mlxbf-bootctl.c | 42 +++++++++++++++++++++++
drivers/platform/mellanox/mlxbf-bootctl.h | 9 +++++
2 files changed, 51 insertions(+)

diff --git a/drivers/platform/mellanox/mlxbf-bootctl.c b/drivers/platform/mellanox/mlxbf-bootctl.c
index fb9f7815c6cd..3ea11250b681 100644
--- a/drivers/platform/mellanox/mlxbf-bootctl.c
+++ b/drivers/platform/mellanox/mlxbf-bootctl.c
@@ -79,6 +79,8 @@ static void __iomem *mlxbf_rsh_scratch_buf_data;
static const char * const mlxbf_rsh_log_level[] = {
"INFO", "WARN", "ERR", "ASSERT"};

+static DEFINE_MUTEX(icm_ops_lock);
+
/* ARM SMC call which is atomic and no need for lock. */
static int mlxbf_bootctl_smc(unsigned int smc_op, int smc_arg)
{
@@ -391,6 +393,44 @@ static ssize_t rsh_log_store(struct device *dev,
return count;
}

+static ssize_t large_icm_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct arm_smccc_res res;
+
+ mutex_lock(&icm_ops_lock);
+ arm_smccc_smc(MLNX_HANDLE_GET_ICM_INFO, 0, 0, 0, 0,
+ 0, 0, 0, &res);
+ mutex_unlock(&icm_ops_lock);
+ if (res.a0)
+ return -EPERM;
+
+ return snprintf(buf, PAGE_SIZE, "0x%lx", res.a1);
+}
+
+static ssize_t large_icm_store(struct device *dev,
+ struct device_attribute *attr,
+ 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 DEVICE_ATTR_RW(post_reset_wdog);
static DEVICE_ATTR_RW(reset_action);
static DEVICE_ATTR_RW(second_reset_action);
@@ -398,6 +438,7 @@ static DEVICE_ATTR_RO(lifecycle_state);
static DEVICE_ATTR_RO(secure_boot_fuse_state);
static DEVICE_ATTR_WO(fw_reset);
static DEVICE_ATTR_WO(rsh_log);
+static DEVICE_ATTR_RW(large_icm);

static struct attribute *mlxbf_bootctl_attrs[] = {
&dev_attr_post_reset_wdog.attr,
@@ -407,6 +448,7 @@ static struct attribute *mlxbf_bootctl_attrs[] = {
&dev_attr_secure_boot_fuse_state.attr,
&dev_attr_fw_reset.attr,
&dev_attr_rsh_log.attr,
+ &dev_attr_large_icm.attr,
NULL
};

diff --git a/drivers/platform/mellanox/mlxbf-bootctl.h b/drivers/platform/mellanox/mlxbf-bootctl.h
index b48243f60a59..75d59ade92be 100644
--- a/drivers/platform/mellanox/mlxbf-bootctl.h
+++ b/drivers/platform/mellanox/mlxbf-bootctl.h
@@ -81,6 +81,15 @@
*/
#define MLXBF_BOOTCTL_FW_RESET 0x8200000D

+/*
+ * 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 MLXBF_BOOTCTL_SIP_SVC_CALL_COUNT 0x8200ff00
#define MLXBF_BOOTCTL_SIP_SVC_UID 0x8200ff01
--
2.30.1