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Commit 07be0382 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/hypfs: add interface for diagnose 0x304 



To provide access to the set-partition-resource-parameter interface
to user space add a new attribute to hypfs/debugfs:
 * s390_hypsfs/diag_304
The data for the query-partition-resource-parameters command can
be access by a read on the attribute. All other diagnose 0x304
requests need to be submitted via ioctl with CAP_SYS_ADMIN rights.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent fded4329

Documentation/ioctl/ioctl-number.txt

+1 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ Code Seq#(hex) Include File Comments 
0x09	all	linux/raid/md_u.h

0x10	00-0F	drivers/char/s390/vmcp.h

0x10	10-1F	arch/s390/include/uapi/sclp_ctl.h

0x10	20-2F	arch/s390/include/uapi/asm/hypfs.h

0x12	all	linux/fs.h

		linux/blkpg.h

0x1b	all	InfiniBand Subsystem	<http://infiniband.sourceforge.net/>

arch/s390/hypfs/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -4,4 +4,4 @@ 


obj-$(CONFIG_S390_HYPFS_FS) += s390_hypfs.o



s390_hypfs-objs := inode.o hypfs_diag.o hypfs_vm.o hypfs_dbfs.o
 
s390_hypfs-objs := inode.o hypfs_diag.o hypfs_vm.o hypfs_dbfs.o hypfs_sprp.o

arch/s390/hypfs/hypfs.h

+7 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/debugfs.h>

#include <linux/workqueue.h>

#include <linux/kref.h>

#include <asm/hypfs.h>



#define REG_FILE_MODE    0440

#define UPDATE_FILE_MODE 0220
@@ -36,6 +37,10 @@ extern int hypfs_vm_init(void); 
extern void hypfs_vm_exit(void);

extern int hypfs_vm_create_files(struct dentry *root);



/* Set Partition-Resource Parameter */

int hypfs_sprp_init(void);

void hypfs_sprp_exit(void);



/* debugfs interface */

struct hypfs_dbfs_file;
@@ -52,6 +57,8 @@ struct hypfs_dbfs_file { 
	int		(*data_create)(void **data, void **data_free_ptr,

				       size_t *size);

	void		(*data_free)(const void *buf_free_ptr);

	long		(*unlocked_ioctl) (struct file *, unsigned int,

					   unsigned long);



	/* Private data for hypfs_dbfs.c */

	struct hypfs_dbfs_data	*data;

arch/s390/hypfs/hypfs_dbfs.c

+16 −0
Original line number Diff line number Diff line
@@ -81,9 +81,25 @@ static ssize_t dbfs_read(struct file *file, char __user *buf, 
	return rc;

}



static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{

	struct hypfs_dbfs_file *df;

	long rc;



	df = file->f_path.dentry->d_inode->i_private;

	mutex_lock(&df->lock);

	if (df->unlocked_ioctl)

		rc = df->unlocked_ioctl(file, cmd, arg);

	else

		rc = -ENOTTY;

	mutex_unlock(&df->lock);

	return rc;

}



static const struct file_operations dbfs_ops = {

	.read		= dbfs_read,

	.llseek		= no_llseek,

	.unlocked_ioctl = dbfs_ioctl,

};



int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df)

arch/s390/hypfs/hypfs_sprp.c

0 → 100644
+141 −0
Original line number Diff line number Diff line 
/*

 *    Hypervisor filesystem for Linux on s390.

 *    Set Partition-Resource Parameter interface.

 *

 *    Copyright IBM Corp. 2013

 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>

 */



#include <linux/compat.h>

#include <linux/errno.h>

#include <linux/gfp.h>

#include <linux/string.h>

#include <linux/types.h>

#include <linux/uaccess.h>

#include <asm/compat.h>

#include <asm/sclp.h>

#include "hypfs.h"



#define DIAG304_SET_WEIGHTS	0

#define DIAG304_QUERY_PRP	1

#define DIAG304_SET_CAPPING	2



#define DIAG304_CMD_MAX		2



static unsigned long hypfs_sprp_diag304(void *data, unsigned long cmd)

{

	register unsigned long _data asm("2") = (unsigned long) data;

	register unsigned long _rc asm("3");

	register unsigned long _cmd asm("4") = cmd;



	asm volatile("diag %1,%2,0x304\n"

		     : "=d" (_rc) : "d" (_data), "d" (_cmd) : "memory");



	return _rc;

}



static void hypfs_sprp_free(const void *data)

{

	free_page((unsigned long) data);

}



static int hypfs_sprp_create(void **data_ptr, void **free_ptr, size_t *size)

{

	unsigned long rc;

	void *data;



	data = (void *) get_zeroed_page(GFP_KERNEL);

	if (!data)

		return -ENOMEM;

	rc = hypfs_sprp_diag304(data, DIAG304_QUERY_PRP);

	if (rc != 1) {

		*data_ptr = *free_ptr = NULL;

		*size = 0;

		free_page((unsigned long) data);

		return -EIO;

	}

	*data_ptr = *free_ptr = data;

	*size = PAGE_SIZE;

	return 0;

}



static int __hypfs_sprp_ioctl(void __user *user_area)

{

	struct hypfs_diag304 diag304;

	unsigned long cmd;

	void __user *udata;

	void *data;

	int rc;



	if (copy_from_user(&diag304, user_area, sizeof(diag304)))

		return -EFAULT;

	if ((diag304.args[0] >> 8) != 0 || diag304.args[1] > DIAG304_CMD_MAX)

		return -EINVAL;



	data = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);

	if (!data)

		return -ENOMEM;



	udata = (void __user *)(unsigned long) diag304.data;

	if (diag304.args[1] == DIAG304_SET_WEIGHTS ||

	    diag304.args[1] == DIAG304_SET_CAPPING)

		if (copy_from_user(data, udata, PAGE_SIZE)) {

			rc = -EFAULT;

			goto out;

		}



	cmd = *(unsigned long *) &diag304.args[0];

	diag304.rc = hypfs_sprp_diag304(data, cmd);



	if (diag304.args[1] == DIAG304_QUERY_PRP)

		if (copy_to_user(udata, data, PAGE_SIZE)) {

			rc = -EFAULT;

			goto out;

		}



	rc = copy_to_user(user_area, &diag304, sizeof(diag304)) ? -EFAULT : 0;

out:

	free_page((unsigned long) data);

	return rc;

}



static long hypfs_sprp_ioctl(struct file *file, unsigned int cmd,

			       unsigned long arg)

{

	void __user *argp;



	if (!capable(CAP_SYS_ADMIN))

		return -EACCES;

	if (is_compat_task())

		argp = compat_ptr(arg);

	else

		argp = (void __user *) arg;

	switch (cmd) {

	case HYPFS_DIAG304:

		return __hypfs_sprp_ioctl(argp);

	default: /* unknown ioctl number */

		return -ENOTTY;

	}

	return 0;

}



static struct hypfs_dbfs_file hypfs_sprp_file = {

	.name		= "diag_304",

	.data_create	= hypfs_sprp_create,

	.data_free	= hypfs_sprp_free,

	.unlocked_ioctl = hypfs_sprp_ioctl,

};



int hypfs_sprp_init(void)

{

	if (!sclp_has_sprp())

		return 0;

	return hypfs_dbfs_create_file(&hypfs_sprp_file);

}



void hypfs_sprp_exit(void)

{

	if (!sclp_has_sprp())

		return;

	hypfs_dbfs_remove_file(&hypfs_sprp_file);

}