[PATCH 6/7] scsi: ufs: Enable writing config descriptor

From: Evan Green
Date: Tue May 29 2018 - 14:19:14 EST


This change enables writing to fields of the config descriptor
via sysfs. It can be used to provision an unprovisioned UFS
device, or reprovision an unlocked device.

Signed-off-by: Evan Green <evgreen@xxxxxxxxxxxx>
---
drivers/scsi/ufs/ufs-sysfs.c | 64 +++++++++++++++++++++++++++++++++++++++++---
1 file changed, 61 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c
index 623c56074572..54e9f3bca9db 100644
--- a/drivers/scsi/ufs/ufs-sysfs.c
+++ b/drivers/scsi/ufs/ufs-sysfs.c
@@ -252,6 +252,31 @@ static ssize_t ufs_sysfs_read_desc_param(struct ufs_hba *hba,
return ret;
}

+static ssize_t ufs_sysfs_write_desc_param(struct ufs_hba *hba,
+ enum desc_idn desc_id,
+ u8 desc_index,
+ u8 param_offset,
+ const char *buf,
+ ssize_t buf_size,
+ u8 width)
+{
+ int ret;
+ unsigned long long value;
+
+ if (kstrtoull(buf, 0, &value))
+ return -EINVAL;
+
+ /* Convert to big endian, and send only the appropriate width. */
+ value = cpu_to_be64(value);
+ ret = ufshcd_rw_desc_param(hba, UPIU_QUERY_OPCODE_WRITE_DESC, desc_id,
+ desc_index, param_offset,
+ (u8 *)&value + 8 - width, width);
+ if (ret)
+ return -EINVAL;
+
+ return buf_size;
+}
+
#define UFS_DESC_PARAM(_name, _puname, _duname, _size) \
static ssize_t _name##_show(struct device *dev, \
struct device_attribute *attr, char *buf) \
@@ -357,8 +382,25 @@ static ssize_t cfg_unit_store(struct device *dev,
return count;
}

-#define UFS_CONFIG_DESC_PARAM(_name, _uname, _size) \
- UFS_DESC_PARAM(cfg_##_name, _uname, CONFIGURATION, _size)
+#define UFS_CONFIG_DESC_PARAM(_name, _puname, _size) \
+static ssize_t cfg_##_name##_show(struct device *dev, \
+ struct device_attribute *attr, char *buf) \
+{ \
+ struct ufs_hba *hba = dev_get_drvdata(dev); \
+ return ufs_sysfs_read_desc_param(hba, \
+ QUERY_DESC_IDN_CONFIGURATION, 0, \
+ CONFIGURATION_DESC_PARAM##_puname, buf, _size); \
+} \
+static ssize_t cfg_##_name##_store(struct device *dev, \
+ struct device_attribute *attr, const char *buf, \
+ size_t count) \
+{ \
+ struct ufs_hba *hba = dev_get_drvdata(dev); \
+ return ufs_sysfs_write_desc_param(hba, \
+ QUERY_DESC_IDN_CONFIGURATION, 0, \
+ CONFIGURATION_DESC_PARAM##_puname, buf, count, _size); \
+} \
+static DEVICE_ATTR_RW(cfg_##_name)

#define UFS_CONFIG_UNIT_DESC_PARAM(_name, _uname, _size) \
static ssize_t unit_##_name##_show(struct device *dev, \
@@ -375,7 +417,23 @@ static ssize_t unit_##_name##_show(struct device *dev, \
return ufs_sysfs_read_desc_param(hba, \
QUERY_DESC_IDN_CONFIGURATION, 0, offset, buf, _size); \
} \
-static DEVICE_ATTR_RO(unit_##_name)
+static ssize_t unit_##_name##_store(struct device *dev, \
+ struct device_attribute *attr, const char *buf, \
+ size_t count) \
+{ \
+ struct ufs_hba *hba = dev_get_drvdata(dev); \
+ size_t offset = CONFIGURATION_DESC_PARAM_UNIT0 + \
+ (hba->sysfs_config_unit * \
+ CONFIGURATION_UNIT_DESC_SIZE) + \
+ CONFIGURATION_UNIT_DESC_PARAM_##_uname; \
+ if (offset + _size > hba->desc_size.conf_desc) { \
+ return -EINVAL; \
+ } \
+ return ufs_sysfs_write_desc_param(hba, \
+ QUERY_DESC_IDN_CONFIGURATION, 0, offset, buf, count, \
+ _size); \
+} \
+static DEVICE_ATTR_RW(unit_##_name)

UFS_CONFIG_DESC_PARAM(number_of_luns, _NUM_LU, 1);
UFS_CONFIG_DESC_PARAM(boot_enable, _BOOT_ENBL, 1);
--
2.13.5