On Fri, Sep 14, 2018 at 2:43 AM Sayali Lokhande <sayalil@xxxxxxxxxxxxxx> wrote:
This patch adds configfs support to provision UFS device at
runtime. This feature can be primarily useful in factory or
assembly line as some devices may be required to be configured
multiple times during initial system development phase.
Configuration Descriptors can be written multiple times until
bConfigDescrLock attribute is zero.
Configuration descriptor buffer consists of Device and Unit
descriptor configurable parameters which are parsed from vendor
specific provisioning file and then passed via configfs node at
runtime to provision ufs device.
CONFIG_CONFIGFS_FS and CONFIG_UFS_PROVISION needs to be enabled
for using this feature.
Usage:
1) To read current configuration descriptor with index X
(where index X can be 0/1/2/3) :
cat /config/<device_name>/ufs_config_desc_X
2) To write configuration descriptor with index X :
echo <config_desc_buf> > /config/<device_name>/ufs_config_desc_X
Signed-off-by: Sayali Lokhande <sayalil@xxxxxxxxxxxxxx>
---
...
diff --git a/drivers/scsi/ufs/ufs-configfs.c b/drivers/scsi/ufs/ufs-configfs.c
new file mode 100644
index 0000000..84ccb1a
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-configfs.c
@@ -0,0 +1,237 @@
...
+static ssize_t ufs_config_desc_0_show(struct config_item *item, char *buf)
+{
+ return ufs_config_desc_show(item, buf, 0);
+}
+
+static ssize_t ufs_config_desc_0_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ return ufshcd_desc_configfs_store(item, buf, count, 0);
+}
+
+static ssize_t ufs_config_desc_1_show(struct config_item *item, char *buf)
+{
+ return ufs_config_desc_show(item, buf, 1);
+}
+
+static ssize_t ufs_config_desc_1_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ return ufshcd_desc_configfs_store(item, buf, count, 1);
+}
+
+static ssize_t ufs_config_desc_2_show(struct config_item *item, char *buf)
+{
+ return ufs_config_desc_show(item, buf, 2);
+}
+
+static ssize_t ufs_config_desc_2_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ return ufshcd_desc_configfs_store(item, buf, count, 2);
+}
+
+static ssize_t ufs_config_desc_3_show(struct config_item *item, char *buf)
+{
+ return ufs_config_desc_show(item, buf, 3);
+}
+
+static ssize_t ufs_config_desc_3_store(struct config_item *item,
+ const char *buf, size_t count)
+{
+ return ufshcd_desc_configfs_store(item, buf, count, 3);
+}
+
The copypasta above and below is not my favorite, but I suppose it's
either this or wrap it all up in a macro that you stamp down 4 times.
I'm not sure if that's really any cleaner, so I guess this is fine.
+static struct configfs_attribute ufshcd_attr_provision_0 = {
+ .ca_name = "ufs_config_desc_0",
+ .ca_mode = 0644,
+ .ca_owner = THIS_MODULE,
+ .show = ufs_config_desc_0_show,
+ .store = ufs_config_desc_0_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_1 = {
+ .ca_name = "ufs_config_desc_1",
+ .ca_mode = 0644,
+ .ca_owner = THIS_MODULE,
+ .show = ufs_config_desc_1_show,
+ .store = ufs_config_desc_1_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_2 = {
+ .ca_name = "ufs_config_desc_2",
+ .ca_mode = 0644,
+ .ca_owner = THIS_MODULE,
+ .show = ufs_config_desc_2_show,
+ .store = ufs_config_desc_2_store,
+};
+
+static struct configfs_attribute ufshcd_attr_provision_3 = {
+ .ca_name = "ufs_config_desc_3",
+ .ca_mode = 0644,
+ .ca_owner = THIS_MODULE,
+ .show = ufs_config_desc_3_show,
+ .store = ufs_config_desc_3_store,
+};
+
+static struct configfs_attribute *ufshcd_attrs[] = {
+ &ufshcd_attr_provision_0,
+ &ufshcd_attr_provision_1,
+ &ufshcd_attr_provision_2,
+ &ufshcd_attr_provision_3,
+ NULL,
+};
+
+static struct config_item_type ufscfg_type = {
+ .ct_attrs = ufshcd_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+void ufshcd_configfs_init(struct ufs_hba *hba, const char *name)
+{
+ int ret;
+ struct config_item *cg_item;
+ struct configfs_subsystem *subsys;
+
+ cg_item = &hba->subsys.su_group.cg_item;
+ sprintf(cg_item->ci_namebuf, "%s", name);
CONFIGFS_ITEM_NAME_LEN is only 20. Is there anything preventing the
device name passed in here from being longer than that? You'd have a
nasty overrun on your hands if not. Maybe snprintf here?
