[PATCH 12/46] mtd: nandsim: Make debugfs logic multi instance capable

[Daniel Walter]

From: Richard Weinberger <rich...@nod.at>

Instead of creating our files in <debugfs>/nandsim/,
create one directory per instance.

Signed-off-by: Richard Weinberger <rich...@nod.at>
---
 drivers/mtd/nand/nandsim.c | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index ab4859d..057cc7a 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -328,6 +328,7 @@ union ns_mem {
  * The structure which describes all the internal simulator data.
  */
 struct nandsim {
+       unsigned int index;
        struct mtd_partition partitions[CONFIG_NANDSIM_MAX_PARTS];
        unsigned int nbparts;
 
@@ -483,6 +484,8 @@ struct grave_page {
 /* MTD structure for NAND controller */
 static struct mtd_info *ns_mtds[NS_MAX_DEVICES];
 
+static struct dentry *dfs_root;
+
 static inline struct nandsim *chip_to_ns(struct nand_chip *chip)
 {
        return (struct nandsim *)(chip + 1);
@@ -560,6 +563,23 @@ static const struct file_operations dfs_fops = {
        .release        = single_release,
 };
 
+static int nandsim_debugfs_init(void)
+{
+       if (!IS_ENABLED(CONFIG_DEBUG_FS))
+               return 0;
+
+       dfs_root = debugfs_create_dir("nandsim", NULL);
+       if (IS_ERR_OR_NULL(dfs_root)) {
+               int err = dfs_root ? -ENODEV : PTR_ERR(dfs_root);
+
+               NS_ERR("cannot create \"nandsim\" debugfs directory, err %d\n",
+                       err);
+               return err;
+       }
+
+       return 0;
+}
+
 /**
  * nandsim_debugfs_create - initialize debugfs
  * @dev: nandsim device description object
@@ -572,15 +592,21 @@ static int nandsim_debugfs_create(struct nandsim *dev)
        struct nandsim_debug_info *dbg = &dev->dbg;
        struct dentry *dent;
        int err;
+       char *dirname;
 
        if (!IS_ENABLED(CONFIG_DEBUG_FS))
                return 0;
 
-       dent = debugfs_create_dir("nandsim", NULL);
+       dirname = kasprintf(GFP_KERNEL, "nandsim%i", dev->index);
+       if (!dirname)
+               return -ENOMEM;
+
+       dent = debugfs_create_dir(dirname, dfs_root);
+       kfree(dirname);
        if (IS_ERR_OR_NULL(dent)) {
                int err = dent ? -ENODEV : PTR_ERR(dent);
 
-               NS_ERR("cannot create \"nandsim\" debugfs directory, err %d\n",
+               NS_ERR("cannot create nandsim debugfs sub-directory, err %d\n",
                        err);
                return err;
        }
@@ -2336,6 +2362,7 @@ static int ns_new_instance(struct nandsim_params *nsparam)
        nsmtd = ns_mtds[0] = nand_to_mtd(chip);
        nand = chip_to_ns(chip);
        nand_set_controller_data(chip, (void *)nand);
+       nand->index = 0;
 
        INIT_LIST_HEAD(&nand->weak_blocks);
        INIT_LIST_HEAD(&nand->grave_pages);
@@ -2557,6 +2584,10 @@ static int __init ns_init_module(void)
 {
        int ret;
 
+       ret = nandsim_debugfs_init();
+       if (ret)
+               return ret;
+
        ret = ns_init_default();
        if (ret)
                return ret;
@@ -2569,6 +2600,7 @@ static void __exit ns_cleanup_module(void)
 {
        ns_cleanup_default();
        misc_deregister(&nandsim_ctrl_cdev);
+       debugfs_remove_recursive(dfs_root);
 }
 module_exit(ns_cleanup_module);
 
-- 
2.8.3