mtd: create per-device and module-scope debugfs entries

Several MTD devices are using debugfs entries created in the root.
This commit provides the means for a standardized subtree, creating
one "mtd" entry at root, and one entry per device inside it, named
after the device.
The tree is registered in add_mtd_device, and released in
del_mtd_device.
Devices docg3, mtdswap and nandsim were updated to use this subtree
instead of custom ones, and their entries were prefixed with the
drivers' names.

Signed-off-by: Mario J. Rugiero <mrugiero@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index b833e6cc684c389985bbe91aec15c2612daf6b5e..84b16133554bebf60f4e42c84bc1fd4274c477a8 100644 (file)
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -1809,37 +1809,22 @@ static int dbg_protection_show(struct seq_file *s, void *p)
 }
 DEBUGFS_RO_ATTR(protection, dbg_protection_show);
 
-static int __init doc_dbg_register(struct docg3 *docg3)
-{
-       struct dentry *root, *entry;
-
-       root = debugfs_create_dir("docg3", NULL);
-       if (!root)
-               return -ENOMEM;
-
-       entry = debugfs_create_file("flashcontrol", S_IRUSR, root, docg3,
-                                 &flashcontrol_fops);
-       if (entry)
-               entry = debugfs_create_file("asic_mode", S_IRUSR, root,
-                                           docg3, &asic_mode_fops);
-       if (entry)
-               entry = debugfs_create_file("device_id", S_IRUSR, root,
-                                           docg3, &device_id_fops);
-       if (entry)
-               entry = debugfs_create_file("protection", S_IRUSR, root,
-                                           docg3, &protection_fops);
-       if (entry) {
-               docg3->debugfs_root = root;
-               return 0;
-       } else {
-               debugfs_remove_recursive(root);
-               return -ENOMEM;
-       }
-}
-
-static void doc_dbg_unregister(struct docg3 *docg3)
+static void __init doc_dbg_register(struct mtd_info *floor)
 {
-       debugfs_remove_recursive(docg3->debugfs_root);
+       struct dentry *root = floor->dbg.dfs_dir;
+       struct docg3 *docg3 = floor->priv;
+
+       if (IS_ERR_OR_NULL(root))
+               return;
+
+       debugfs_create_file("docg3_flashcontrol", S_IRUSR, root, docg3,
+                           &flashcontrol_fops);
+       debugfs_create_file("docg3_asic_mode", S_IRUSR, root, docg3,
+                           &asic_mode_fops);
+       debugfs_create_file("docg3_device_id", S_IRUSR, root, docg3,
+                           &device_id_fops);
+       debugfs_create_file("docg3_protection", S_IRUSR, root, docg3,
+                           &protection_fops);
 }
 
 /**
@@ -2114,6 +2099,8 @@ static int __init docg3_probe(struct platform_device *pdev)
                                                0);
                if (ret)
                        goto err_probe;
+
+               doc_dbg_register(cascade->floors[floor]);
        }
 
        ret = doc_register_sysfs(pdev, cascade);
@@ -2121,7 +2108,6 @@ static int __init docg3_probe(struct platform_device *pdev)
                goto err_probe;
 
        platform_set_drvdata(pdev, cascade);
-       doc_dbg_register(cascade->floors[0]->priv);
        return 0;
 
 notfound:
@@ -2148,7 +2134,6 @@ static int docg3_release(struct platform_device *pdev)
        int floor;
 
        doc_unregister_sysfs(pdev, cascade);
-       doc_dbg_unregister(docg3);
        for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
                if (cascade->floors[floor])
                        doc_release_device(cascade->floors[floor]);

diff --git a/drivers/mtd/devices/docg3.h b/drivers/mtd/devices/docg3.h
index 19fb93f96a3a4eca50f4f8b6bb01728b48bb064f..e99946575398e4798e29af5b4c5cbb3f9498bdf2 100644 (file)
--- a/drivers/mtd/devices/docg3.h
+++ b/drivers/mtd/devices/docg3.h
@@ -299,7 +299,6 @@ struct docg3_cascade {
  * @oob_autoecc: if 1, use only bytes 0-7, 15, and fill the others with HW ECC
  *               if 0, use all the 16 bytes.
  * @oob_write_buf: prepared OOB for next page_write
- * @debugfs_root: debugfs root node
  */
 struct docg3 {
        struct device *dev;
@@ -312,7 +311,6 @@ struct docg3 {
        loff_t oob_write_ofs;
        int oob_autoecc;
        u8 oob_write_buf[DOC_LAYOUT_OOB_SIZE];
-       struct dentry *debugfs_root;
 };
 
 #define doc_err(fmt, arg...) dev_err(docg3->dev, (fmt), ## arg)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 956382cea2568b3ee9c8721e5ab2acd522ce66f5..f872a99501ed0478bb4f5dc3ea86890d146c5ca1 100644 (file)
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -40,6 +40,7 @@
 #include <linux/slab.h>
 #include <linux/reboot.h>
 #include <linux/leds.h>
+#include <linux/debugfs.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
@@ -477,6 +478,8 @@ int mtd_pairing_groups(struct mtd_info *mtd)
 }
 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
 
+static struct dentry *dfs_dir_mtd;
+
 /**
  *     add_mtd_device - register an MTD device
  *     @mtd: pointer to new MTD device info structure
@@ -552,6 +555,14 @@ int add_mtd_device(struct mtd_info *mtd)
        if (error)
                goto fail_added;
 
+       if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
+               mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
+               if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
+                       pr_debug("mtd device %s won't show data in debugfs\n",
+                                dev_name(&mtd->dev));
+               }
+       }
+
        device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
                      "mtd%dro", i);
 
@@ -594,6 +605,8 @@ int del_mtd_device(struct mtd_info *mtd)
 
        mutex_lock(&mtd_table_mutex);
 
+       debugfs_remove_recursive(mtd->dbg.dfs_dir);
+
        if (idr_find(&mtd_idr, mtd->index) != mtd) {
                ret = -ENODEV;
                goto out_error;
@@ -1811,6 +1824,8 @@ static int __init init_mtd(void)
        if (ret)
                goto out_procfs;
 
+       dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
+
        return 0;
 
 out_procfs:
@@ -1826,6 +1841,7 @@ err_reg:
 
 static void __exit cleanup_mtd(void)
 {
+       debugfs_remove_recursive(dfs_dir_mtd);
        cleanup_mtdchar();
        if (proc_mtd)
                remove_proc_entry("mtd", NULL);

diff --git a/drivers/mtd/mtdswap.c b/drivers/mtd/mtdswap.c
index f12879a3d4ff52bc1ce0e0f794bab4d5a689c25f..6b17932fe5576b68db3581e16da455da4472930b 100644 (file)
--- a/drivers/mtd/mtdswap.c
+++ b/drivers/mtd/mtdswap.c
@@ -138,8 +138,6 @@ struct mtdswap_dev {
 
        char *page_buf;
        char *oob_buf;
-
-       struct dentry *debugfs_root;
 };
 
 struct mtdswap_oobdata {
@@ -1318,26 +1316,19 @@ static int mtdswap_add_debugfs(struct mtdswap_dev *d)
        struct gendisk *gd = d->mbd_dev->disk;
        struct device *dev = disk_to_dev(gd);
 
-       struct dentry *root;
+       struct dentry *root = d->mtd->dbg.dfs_dir;
        struct dentry *dent;
 
-       root = debugfs_create_dir(gd->disk_name, NULL);
-       if (IS_ERR(root))
+       if (!IS_ENABLED(CONFIG_DEBUG_FS))
                return 0;
 
-       if (!root) {
-               dev_err(dev, "failed to initialize debugfs\n");
+       if (IS_ERR_OR_NULL(root))
                return -1;
-       }
-
-       d->debugfs_root = root;
 
-       dent = debugfs_create_file("stats", S_IRUSR, root, d,
+       dent = debugfs_create_file("mtdswap_stats", S_IRUSR, root, d,
                                &mtdswap_fops);
        if (!dent) {
                dev_err(d->dev, "debugfs_create_file failed\n");
-               debugfs_remove_recursive(root);
-               d->debugfs_root = NULL;
                return -1;
        }
 
@@ -1540,7 +1531,6 @@ static void mtdswap_remove_dev(struct mtd_blktrans_dev *dev)
 {
        struct mtdswap_dev *d = MTDSWAP_MBD_TO_MTDSWAP(dev);
 
-       debugfs_remove_recursive(d->debugfs_root);
        del_mtd_blktrans_dev(dev);
        mtdswap_cleanup(d);
        kfree(d);

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 03a0d057bf2f80b3ea4c3f397eb1f607697aad3c..1ddf0b73c24661833211732a55016d57ee7ac3a0 100644 (file)
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -287,11 +287,6 @@ MODULE_PARM_DESC(bch,               "Enable BCH ecc and set how many bits should "
 /* Maximum page cache pages needed to read or write a NAND page to the cache_file */
 #define NS_MAX_HELD_PAGES 16
 
-struct nandsim_debug_info {
-       struct dentry *dfs_root;
-       struct dentry *dfs_wear_report;
-};
-
 /*
  * A union to represent flash memory contents and flash buffer.
  */
@@ -370,8 +365,6 @@ struct nandsim {
        void *file_buf;
        struct page *held_pages[NS_MAX_HELD_PAGES];
        int held_cnt;
-
-       struct nandsim_debug_info dbg;
 };
 
 /*
@@ -524,39 +517,23 @@ static const struct file_operations dfs_fops = {
  */
 static int nandsim_debugfs_create(struct nandsim *dev)
 {
-       struct nandsim_debug_info *dbg = &dev->dbg;
+       struct dentry *root = nsmtd->dbg.dfs_dir;
        struct dentry *dent;
 
        if (!IS_ENABLED(CONFIG_DEBUG_FS))
                return 0;
 
-       dent = debugfs_create_dir("nandsim", NULL);
-       if (!dent) {
-               NS_ERR("cannot create \"nandsim\" debugfs directory\n");
-               return -ENODEV;
-       }
-       dbg->dfs_root = dent;
+       if (IS_ERR_OR_NULL(root))
+               return -1;
 
-       dent = debugfs_create_file("wear_report", S_IRUSR,
-                                  dbg->dfs_root, dev, &dfs_fops);
-       if (!dent)
-               goto out_remove;
-       dbg->dfs_wear_report = dent;
+       dent = debugfs_create_file("nandsim_wear_report", S_IRUSR,
+                                  root, dev, &dfs_fops);
+       if (IS_ERR_OR_NULL(dent)) {
+               NS_ERR("cannot create \"nandsim_wear_report\" debugfs entry\n");
+               return -1;
+       }
 
        return 0;
-
-out_remove:
-       debugfs_remove_recursive(dbg->dfs_root);
-       return -ENODEV;
-}
-
-/**
- * nandsim_debugfs_remove - destroy all debugfs files
- */
-static void nandsim_debugfs_remove(struct nandsim *ns)
-{
-       if (IS_ENABLED(CONFIG_DEBUG_FS))
-               debugfs_remove_recursive(ns->dbg.dfs_root);
 }
 
 /*
@@ -2352,9 +2329,6 @@ static int __init ns_init_module(void)
        if ((retval = setup_wear_reporting(nsmtd)) != 0)
                goto err_exit;
 
-       if ((retval = nandsim_debugfs_create(nand)) != 0)
-               goto err_exit;
-
        if ((retval = init_nandsim(nsmtd)) != 0)
                goto err_exit;
 
@@ -2370,6 +2344,9 @@ static int __init ns_init_module(void)
        if (retval != 0)
                goto err_exit;
 
+       if ((retval = nandsim_debugfs_create(nand)) != 0)
+               goto err_exit;
+
         return 0;
 
 err_exit:
@@ -2395,7 +2372,6 @@ static void __exit ns_cleanup_module(void)
        struct nandsim *ns = nand_get_controller_data(chip);
        int i;
 
-       nandsim_debugfs_remove(ns);
        free_nandsim(ns);    /* Free nandsim private resources */
        nand_release(nsmtd); /* Unregister driver */
        for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)

diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index f8a2ef239c60adf6ce49f5ebcdbf576db0bd434d..6cd0f6b7658b38c73be72e3a085d93a6362d2588 100644 (file)
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -206,6 +206,15 @@ struct mtd_pairing_scheme {
 
 struct module; /* only needed for owner field in mtd_info */
 
+/**
+ * struct mtd_debug_info - debugging information for an MTD device.
+ *
+ * @dfs_dir: direntry object of the MTD device debugfs directory
+ */
+struct mtd_debug_info {
+       struct dentry *dfs_dir;
+};
+
 struct mtd_info {
        u_char type;
        uint32_t flags;
@@ -346,6 +355,7 @@ struct mtd_info {
        struct module *owner;
        struct device dev;
        int usecount;
+       struct mtd_debug_info dbg;
 };
 
 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,