Commit 9fe2a701 authored by Srivatsa Vaddagiri's avatar Srivatsa Vaddagiri Committed by Konrad Rzeszutek Wilk
Browse files

debugfs: Add support to print u32 array in debugfs 



Move the code from Xen to debugfs to make the code common
for other users as well.

Accked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSrivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: default avatarSuzuki Poulose <suzuki@in.ibm.com>
[v1: Fixed rebase issues]
[v2: Fixed PPC compile issues]
Signed-off-by: default avatarRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent e816b57a

arch/x86/xen/debugfs.c

+0 −104
Original line number Diff line number Diff line
@@ -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);

}

arch/x86/xen/debugfs.h

+0 −4
Original line number Diff line number Diff line
@@ -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 */

arch/x86/xen/spinlock.c

+6 −6
Original line number Diff line number Diff line
@@ -440,11 +440,11 @@ 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,

	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,

	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,

	debugfs_create_u32_array("histo_blocked", 0444, d_spin_debug,

				spinlock_stats.histo_spin_blocked, HISTO_BUCKETS + 1);



	return 0;

fs/debugfs/file.c

+128 −0
Original line number Diff line number Diff line
@@ -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



/*

include/linux/debugfs.h

+11 −0
Original line number Diff line number Diff line
@@ -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

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