diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2011-02-22 18:24:26 +0100 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2011-02-22 18:41:48 +0100 |
commit | 695884fb8acd9857e0e7120ccb2150e30f4b8fef (patch) | |
tree | 49aa424c1a021ce432e9fa5ea29d37a23e4e30cc /arch/s390/hypfs/hypfs_dbfs.c | |
parent | 5df91509d324d44cfb11e55d9cb02fe18b53b045 (diff) | |
parent | 04bea68b2f0eeebb089ecc67b618795925268b4a (diff) |
Merge branch 'devicetree/for-x86' of git://git.secretlab.ca/git/linux-2.6 into x86/platform
Reason: x86 devicetree support for ce4100 depends on those device tree
changes scheduled for .39.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/s390/hypfs/hypfs_dbfs.c')
-rw-r--r-- | arch/s390/hypfs/hypfs_dbfs.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/s390/hypfs/hypfs_dbfs.c b/arch/s390/hypfs/hypfs_dbfs.c new file mode 100644 index 00000000000..b478013b7fe --- /dev/null +++ b/arch/s390/hypfs/hypfs_dbfs.c @@ -0,0 +1,116 @@ +/* + * Hypervisor filesystem for Linux on s390 - debugfs interface + * + * Copyright (C) IBM Corp. 2010 + * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com> + */ + +#include <linux/slab.h> +#include "hypfs.h" + +static struct dentry *dbfs_dir; + +static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f) +{ + struct hypfs_dbfs_data *data; + + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return NULL; + kref_init(&data->kref); + data->dbfs_file = f; + return data; +} + +static void hypfs_dbfs_data_free(struct kref *kref) +{ + struct hypfs_dbfs_data *data; + + data = container_of(kref, struct hypfs_dbfs_data, kref); + data->dbfs_file->data_free(data->buf_free_ptr); + kfree(data); +} + +static void data_free_delayed(struct work_struct *work) +{ + struct hypfs_dbfs_data *data; + struct hypfs_dbfs_file *df; + + df = container_of(work, struct hypfs_dbfs_file, data_free_work.work); + mutex_lock(&df->lock); + data = df->data; + df->data = NULL; + mutex_unlock(&df->lock); + kref_put(&data->kref, hypfs_dbfs_data_free); +} + +static ssize_t dbfs_read(struct file *file, char __user *buf, + size_t size, loff_t *ppos) +{ + struct hypfs_dbfs_data *data; + struct hypfs_dbfs_file *df; + ssize_t rc; + + if (*ppos != 0) + return 0; + + df = file->f_path.dentry->d_inode->i_private; + mutex_lock(&df->lock); + if (!df->data) { + data = hypfs_dbfs_data_alloc(df); + if (!data) { + mutex_unlock(&df->lock); + return -ENOMEM; + } + rc = df->data_create(&data->buf, &data->buf_free_ptr, + &data->size); + if (rc) { + mutex_unlock(&df->lock); + kfree(data); + return rc; + } + df->data = data; + schedule_delayed_work(&df->data_free_work, HZ); + } + data = df->data; + kref_get(&data->kref); + mutex_unlock(&df->lock); + + rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size); + kref_put(&data->kref, hypfs_dbfs_data_free); + return rc; +} + +static const struct file_operations dbfs_ops = { + .read = dbfs_read, + .llseek = no_llseek, +}; + +int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df) +{ + df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df, + &dbfs_ops); + if (IS_ERR(df->dentry)) + return PTR_ERR(df->dentry); + mutex_init(&df->lock); + INIT_DELAYED_WORK(&df->data_free_work, data_free_delayed); + return 0; +} + +void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df) +{ + debugfs_remove(df->dentry); +} + +int hypfs_dbfs_init(void) +{ + dbfs_dir = debugfs_create_dir("s390_hypfs", NULL); + if (IS_ERR(dbfs_dir)) + return PTR_ERR(dbfs_dir); + return 0; +} + +void hypfs_dbfs_exit(void) +{ + debugfs_remove(dbfs_dir); +} |