5 files changed, 145 insertions, 114 deletions

diff --git a/arch/x86/xen/debugfs.c b/arch/x86/xen/debugfs.c
index ef1db1900d86..c8377fb26cdf 100644
--- a/arch/x86/xen/debugfs.c
+++ b/arch/x86/xen/debugfs.c
@@ -19,107 +19,3 @@ struct dentry * __init xen_init_debugfs(void)
         return d_xen_debug;
 }
 
-struct array_data
-{
-        void *array;
-        unsigned elements;
-};
-
-static int u32_array_open(struct inode *inode, struct file *file)
-{
-        file->private_data = NULL;
-        return nonseekable_open(inode, file);
-}
-
-static size_t format_array(char *buf, size_t bufsize, const char *fmt,
-                           u32 *array, unsigned array_size)
-{
-        size_t ret = 0;
-        unsigned i;
-
-        for(i = 0; i < array_size; i++) {
-                size_t len;
-
-                len = snprintf(buf, bufsize, fmt, array[i]);
-                len++;  /* ' ' or '\n' */
-                ret += len;
-
-                if (buf) {
-                        buf += len;
-                        bufsize -= len;
-                        buf[-1] = (i == array_size-1) ? '\n' : ' ';
-                }
-        }
-
-        ret++;          /* \0 */
-        if (buf)
-                *buf = '\0';
-
-        return ret;
-}
-
-static char *format_array_alloc(const char *fmt, u32 *array, unsigned array_size)
-{
-        size_t len = format_array(NULL, 0, fmt, array, array_size);
-        char *ret;
-
-        ret = kmalloc(len, GFP_KERNEL);
-        if (ret == NULL)
-                return NULL;
-
-        format_array(ret, len, fmt, array, array_size);
-        return ret;
-}
-
-static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
-                              loff_t *ppos)
-{
-        struct inode *inode = file->f_path.dentry->d_inode;
-        struct array_data *data = inode->i_private;
-        size_t size;
-
-        if (*ppos == 0) {
-                if (file->private_data) {
-                        kfree(file->private_data);
-                        file->private_data = NULL;
-                }
-
-                file->private_data = format_array_alloc("%u", data->array, data->elements);
-        }
-
-        size = 0;
-        if (file->private_data)
-                size = strlen(file->private_data);
-
-        return simple_read_from_buffer(buf, len, ppos, file->private_data, size);
-}
-
-static int xen_array_release(struct inode *inode, struct file *file)
-{
-        kfree(file->private_data);
-
-        return 0;
-}
-
-static const struct file_operations u32_array_fops = {
-        .owner  = THIS_MODULE,
-        .open   = u32_array_open,
-        .release= xen_array_release,
-        .read   = u32_array_read,
-        .llseek = no_llseek,
-};
-
-struct dentry *xen_debugfs_create_u32_array(const char *name, umode_t mode,
-                                            struct dentry *parent,
-                                            u32 *array, unsigned elements)
-{
-        struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
-
-        if (data == NULL)
-                return NULL;
-
-        data->array = array;
-        data->elements = elements;
-
-        return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
-}
diff --git a/arch/x86/xen/debugfs.h b/arch/x86/xen/debugfs.h
index 78d25499be5b..12ebf3325c7b 100644
--- a/arch/x86/xen/debugfs.h
+++ b/arch/x86/xen/debugfs.h
@@ -3,8 +3,4 @@
 
 struct dentry * __init xen_init_debugfs(void);
 
-struct dentry *xen_debugfs_create_u32_array(const char *name, umode_t mode,
-                                            struct dentry *parent,
-                                            u32 *array, unsigned elements);
-
 #endif /* _XEN_DEBUGFS_H */
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index d69cc6c3f808..83e866d714ce 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -440,12 +440,12 @@ static int __init xen_spinlock_debugfs(void)
         debugfs_create_u64("time_total", 0444, d_spin_debug,
                            &spinlock_stats.time_total);
 
-        xen_debugfs_create_u32_array("histo_total", 0444, d_spin_debug,
-                                     spinlock_stats.histo_spin_total, HISTO_BUCKETS + 1);
-        xen_debugfs_create_u32_array("histo_spinning", 0444, d_spin_debug,
-                                     spinlock_stats.histo_spin_spinning, HISTO_BUCKETS + 1);
-        xen_debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug,
-                                     spinlock_stats.histo_spin_blocked, HISTO_BUCKETS + 1);
+        debugfs_create_u32_array("histo_total", 0444, d_spin_debug,
+                                spinlock_stats.histo_spin_total, HISTO_BUCKETS + 1);
+        debugfs_create_u32_array("histo_spinning", 0444, d_spin_debug,
+                                spinlock_stats.histo_spin_spinning, HISTO_BUCKETS + 1);
+        debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug,
+                                spinlock_stats.histo_spin_blocked, HISTO_BUCKETS + 1);
 
         return 0;
 }
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 5dfafdd1dbd3..2340f6978d6e 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -20,6 +20,7 @@
 #include <linux/namei.h>
 #include <linux/debugfs.h>
 #include <linux/io.h>
+#include <linux/slab.h>
 
 static ssize_t default_read_file(struct file *file, char __user *buf,
                                  size_t count, loff_t *ppos)
@@ -520,6 +521,133 @@ struct dentry *debugfs_create_blob(const char *name, umode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_blob);
 
+struct array_data {
+        void *array;
+        u32 elements;
+};
+
+static int u32_array_open(struct inode *inode, struct file *file)
+{
+        file->private_data = NULL;
+        return nonseekable_open(inode, file);
+}
+
+static size_t format_array(char *buf, size_t bufsize, const char *fmt,
+                           u32 *array, u32 array_size)
+{
+        size_t ret = 0;
+        u32 i;
+
+        for (i = 0; i < array_size; i++) {
+                size_t len;
+
+                len = snprintf(buf, bufsize, fmt, array[i]);
+                len++;  /* ' ' or '\n' */
+                ret += len;
+
+                if (buf) {
+                        buf += len;
+                        bufsize -= len;
+                        buf[-1] = (i == array_size-1) ? '\n' : ' ';
+                }
+        }
+
+        ret++;          /* \0 */
+        if (buf)
+                *buf = '\0';
+
+        return ret;
+}
+
+static char *format_array_alloc(const char *fmt, u32 *array,
+                                                u32 array_size)
+{
+        size_t len = format_array(NULL, 0, fmt, array, array_size);
+        char *ret;
+
+        ret = kmalloc(len, GFP_KERNEL);
+        if (ret == NULL)
+                return NULL;
+
+        format_array(ret, len, fmt, array, array_size);
+        return ret;
+}
+
+static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
+                              loff_t *ppos)
+{
+        struct inode *inode = file->f_path.dentry->d_inode;
+        struct array_data *data = inode->i_private;
+        size_t size;
+
+        if (*ppos == 0) {
+                if (file->private_data) {
+                        kfree(file->private_data);
+                        file->private_data = NULL;
+                }
+
+                file->private_data = format_array_alloc("%u", data->array,
+                                                              data->elements);
+        }
+
+        size = 0;
+        if (file->private_data)
+                size = strlen(file->private_data);
+
+        return simple_read_from_buffer(buf, len, ppos,
+                                        file->private_data, size);
+}
+
+static int u32_array_release(struct inode *inode, struct file *file)
+{
+        kfree(file->private_data);
+
+        return 0;
+}
+
+static const struct file_operations u32_array_fops = {
+        .owner   = THIS_MODULE,
+        .open    = u32_array_open,
+        .release = u32_array_release,
+        .read    = u32_array_read,
+        .llseek  = no_llseek,
+};
+
+/**
+ * debugfs_create_u32_array - create a debugfs file that is used to read u32
+ * array.
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          file will be created in the root of the debugfs filesystem.
+ * @array: u32 array that provides data.
+ * @elements: total number of elements in the array.
+ *
+ * This function creates a file in debugfs with the given name that exports
+ * @array as data. If the @mode variable is so set it can be read from.
+ * Writing is not supported. Seek within the file is also not supported.
+ * Once array is created its size can not be changed.
+ *
+ * The function returns a pointer to dentry on success. If debugfs is not
+ * enabled in the kernel, the value -%ENODEV will be returned.
+ */
+struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
+                                            struct dentry *parent,
+                                            u32 *array, u32 elements)
+{
+        struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
+
+        if (data == NULL)
+                return NULL;
+
+        data->array = array;
+        data->elements = elements;
+
+        return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
+
 #ifdef CONFIG_HAS_IOMEM
 
 /*
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index ae36b72c22f3..66c434f5dd1e 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -93,6 +93,10 @@ struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
 int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
                          int nregs, void __iomem *base, char *prefix);
 
+struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
+                                        struct dentry *parent,
+                                        u32 *array, u32 elements);
+
 bool debugfs_initialized(void);
 
 #else
@@ -219,6 +223,13 @@ static inline bool debugfs_initialized(void)
         return false;
 }
 
+static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
+                                        struct dentry *parent,
+                                        u32 *array, u32 elements)
+{
+        return ERR_PTR(-ENODEV);
+}
+
 #endif
 
 #endif