scsi: qla2xxx: Add debugfs create/delete helpers

Define a few helpful macros for creating debugfs files.

Link: https://lore.kernel.org/r/20220826102559.17474-4-njavali@marvell.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 3ec6a200942ee90f60e5783e6e8223790a6cbc33..22274b405d0101ce3677a2611d88d7e85dfaaa7d 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -35,6 +35,11 @@
 
 #include <uapi/scsi/fc/fc_els.h>
 
+#define QLA_DFS_DEFINE_DENTRY(_debugfs_file_name) \
+       struct dentry *dfs_##_debugfs_file_name
+#define QLA_DFS_ROOT_DEFINE_DENTRY(_debugfs_file_name) \
+       struct dentry *qla_dfs_##_debugfs_file_name
+
 /* Big endian Fibre Channel S_ID (source ID) or D_ID (destination ID). */
 typedef struct {
        uint8_t domain;

diff --git a/drivers/scsi/qla2xxx/qla_dfs.c b/drivers/scsi/qla2xxx/qla_dfs.c
index 85bd0e468d43edaff3610ad40f0fc6bea4bbc924..777808af56347311363692124d3f0dbe802e09da 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_dfs.c
+++ b/drivers/scsi/qla2xxx/qla_dfs.c
@@ -489,6 +489,99 @@ qla_dfs_naqp_show(struct seq_file *s, void *unused)
        return 0;
 }
 
+/*
+ * Helper macros for setting up debugfs entries.
+ * _name: The name of the debugfs entry
+ * _ctx_struct: The context that was passed when creating the debugfs file
+ *
+ * QLA_DFS_SETUP_RD could be used when there is only a show function.
+ * - show function take the name qla_dfs_<sysfs-name>_show
+ *
+ * QLA_DFS_SETUP_RW could be used when there are both show and write functions.
+ * - show function take the name  qla_dfs_<sysfs-name>_show
+ * - write function take the name qla_dfs_<sysfs-name>_write
+ *
+ * To have a new debugfs entry, do:
+ * 1. Create a "struct dentry *" in the appropriate structure in the format
+ * dfs_<sysfs-name>
+ * 2. Setup debugfs entries using QLA_DFS_SETUP_RD / QLA_DFS_SETUP_RW
+ * 3. Create debugfs file in qla2x00_dfs_setup() using QLA_DFS_CREATE_FILE
+ * or QLA_DFS_ROOT_CREATE_FILE
+ * 4. Remove debugfs file in qla2x00_dfs_remove() using QLA_DFS_REMOVE_FILE
+ * or QLA_DFS_ROOT_REMOVE_FILE
+ *
+ * Example for creating "TEST" sysfs file:
+ * 1. struct qla_hw_data { ... struct dentry *dfs_TEST; }
+ * 2. QLA_DFS_SETUP_RD(TEST, scsi_qla_host_t);
+ * 3. In qla2x00_dfs_setup():
+ * QLA_DFS_CREATE_FILE(ha, TEST, 0600, ha->dfs_dir, vha);
+ * 4. In qla2x00_dfs_remove():
+ * QLA_DFS_REMOVE_FILE(ha, TEST);
+ */
+#define QLA_DFS_SETUP_RD(_name, _ctx_struct)                           \
+static int                                                             \
+qla_dfs_##_name##_open(struct inode *inode, struct file *file)         \
+{                                                                      \
+       _ctx_struct *__ctx = inode->i_private;                          \
+                                                                       \
+       return single_open(file, qla_dfs_##_name##_show, __ctx);        \
+}                                                                      \
+                                                                       \
+static const struct file_operations qla_dfs_##_name##_ops = {          \
+       .open           = qla_dfs_##_name##_open,                       \
+       .read           = seq_read,                                     \
+       .llseek         = seq_lseek,                                    \
+       .release        = single_release,                               \
+};
+
+#define QLA_DFS_SETUP_RW(_name, _ctx_struct)                           \
+static int                                                             \
+qla_dfs_##_name##_open(struct inode *inode, struct file *file)         \
+{                                                                      \
+       _ctx_struct *__ctx = inode->i_private;                          \
+                                                                       \
+       return single_open(file, qla_dfs_##_name##_show, __ctx);        \
+}                                                                      \
+                                                                       \
+static const struct file_operations qla_dfs_##_name##_ops = {          \
+       .open           = qla_dfs_##_name##_open,                       \
+       .read           = seq_read,                                     \
+       .llseek         = seq_lseek,                                    \
+       .release        = single_release,                               \
+       .write          = qla_dfs_##_name##_write,                      \
+};
+
+#define QLA_DFS_ROOT_CREATE_FILE(_name, _perm, _ctx)                   \
+       do {                                                            \
+               if (!qla_dfs_##_name)                                   \
+                       qla_dfs_##_name = debugfs_create_file(#_name,   \
+                                       _perm, qla2x00_dfs_root, _ctx,  \
+                                       &qla_dfs_##_name##_ops);        \
+       } while (0)
+
+#define QLA_DFS_ROOT_REMOVE_FILE(_name)                                        \
+       do {                                                            \
+               if (qla_dfs_##_name) {                                  \
+                       debugfs_remove(qla_dfs_##_name);                \
+                       qla_dfs_##_name = NULL;                         \
+               }                                                       \
+       } while (0)
+
+#define QLA_DFS_CREATE_FILE(_struct, _name, _perm, _parent, _ctx)      \
+       do {                                                            \
+               (_struct)->dfs_##_name = debugfs_create_file(#_name,    \
+                                       _perm, _parent, _ctx,           \
+                                       &qla_dfs_##_name##_ops)         \
+       } while (0)
+
+#define QLA_DFS_REMOVE_FILE(_struct, _name)                            \
+       do {                                                            \
+               if ((_struct)->dfs_##_name) {                           \
+                       debugfs_remove((_struct)->dfs_##_name);         \
+                       (_struct)->dfs_##_name = NULL;                  \
+               }                                                       \
+       } while (0)
+
 static int
 qla_dfs_naqp_open(struct inode *inode, struct file *file)
 {