[IA64] Itanium MC Error Injection Tool: Driver sysfs interface

/*

 * err_inject.c -

 *	1.) Inject errors to a processor.

 *	2.) Query error injection capabilities.

 * This driver along with user space code can be acting as an error

 * injection tool.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or

 * NON INFRINGEMENT.  See the GNU General Public License for more

 * details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 *

 * Written by: Fenghua Yu <fenghua.yu@intel.com>, Intel Corporation

 * Copyright (C) 2006, Intel Corp.  All rights reserved.

 *

 */

#include <linux/sysdev.h>

#include <linux/init.h>

#include <linux/mm.h>

#include <linux/cpu.h>

#include <linux/module.h>

#define ERR_INJ_DEBUG

#define ERR_DATA_BUFFER_SIZE 3 		// Three 8-byte;

#define define_one_ro(name) 						\

static SYSDEV_ATTR(name, 0444, show_##name, NULL)

#define define_one_rw(name) 						\

static SYSDEV_ATTR(name, 0644, show_##name, store_##name)

static u64 call_start[NR_CPUS];

static u64 phys_addr[NR_CPUS];

static u64 err_type_info[NR_CPUS];

static u64 err_struct_info[NR_CPUS];

static struct {

	u64 data1;

	u64 data2;

	u64 data3;

} __attribute__((__aligned__(16))) err_data_buffer[NR_CPUS];

static s64 status[NR_CPUS];

static u64 capabilities[NR_CPUS];

static u64 resources[NR_CPUS];

#define show(name) 							\

static ssize_t 								\

show_##name(struct sys_device *dev, char *buf)				\

{									\

	u32 cpu=dev->id;						\

	return sprintf(buf, "%lx\n", name[cpu]);			\

}

#define store(name)							\

static ssize_t 								\

store_##name(struct sys_device *dev, const char *buf, size_t size)	\

{									\

	unsigned int cpu=dev->id;					\

	name[cpu] = simple_strtoull(buf, NULL, 16);			\

	return size;							\

}

show(call_start)

/* It's user's responsibility to call the PAL procedure on a specific

 * processor. The cpu number in driver is only used for storing data.

 */

static ssize_t

store_call_start(struct sys_device *dev, const char *buf, size_t size)

{

	unsigned int cpu=dev->id;

	unsigned long call_start = simple_strtoull(buf, NULL, 16);

#ifdef ERR_INJ_DEBUG

	printk(KERN_DEBUG "pal_mc_err_inject for cpu%d:\n", cpu);

	printk(KERN_DEBUG "err_type_info=%lx,\n", err_type_info[cpu]);

	printk(KERN_DEBUG "err_struct_info=%lx,\n", err_struct_info[cpu]);

	printk(KERN_DEBUG "err_data_buffer=%lx, %lx, %lx.\n",

			  err_data_buffer[cpu].data1,

			  err_data_buffer[cpu].data2,

			  err_data_buffer[cpu].data3);

#endif

	switch (call_start) {

	    case 0: /* Do nothing. */

		break;

	    case 1: /* Call pal_mc_error_inject in physical mode. */

		status[cpu]=ia64_pal_mc_error_inject_phys(err_type_info[cpu],

					err_struct_info[cpu],

					ia64_tpa(&err_data_buffer[cpu]),

					&capabilities[cpu],

			 		&resources[cpu]);

		break;

	    case 2: /* Call pal_mc_error_inject in virtual mode. */

		status[cpu]=ia64_pal_mc_error_inject_virt(err_type_info[cpu],

					err_struct_info[cpu],

					ia64_tpa(&err_data_buffer[cpu]),

					&capabilities[cpu],

			 		&resources[cpu]);

		break;

	    default:

		status[cpu] = -EINVAL;

		break;

	}

#ifdef ERR_INJ_DEBUG

	printk(KERN_DEBUG "Returns: status=%d,\n", (int)status[cpu]);

	printk(KERN_DEBUG "capapbilities=%lx,\n", capabilities[cpu]);

	printk(KERN_DEBUG "resources=%lx\n", resources[cpu]);

#endif

	return size;

}

show(err_type_info)

store(err_type_info)

static ssize_t

show_virtual_to_phys(struct sys_device *dev, char *buf)

{

	unsigned int cpu=dev->id;

	return sprintf(buf, "%lx\n", phys_addr[cpu]);

}

static ssize_t

store_virtual_to_phys(struct sys_device *dev, const char *buf, size_t size)

{

	unsigned int cpu=dev->id;

	u64 virt_addr=simple_strtoull(buf, NULL, 16);

	int ret;

        ret = get_user_pages(current, current->mm, virt_addr,

                        1, VM_READ, 0, NULL, NULL);

	if (ret<=0) {

#ifdef ERR_INJ_DEBUG

		printk("Virtual address %lx is not existing.\n",virt_addr);

#endif

		return -EINVAL;

	}

	phys_addr[cpu] = ia64_tpa(virt_addr);

	return size;

}

show(err_struct_info)

store(err_struct_info)

static ssize_t

show_err_data_buffer(struct sys_device *dev, char *buf)

{

	unsigned int cpu=dev->id;

	return sprintf(buf, "%lx, %lx, %lx\n",

			err_data_buffer[cpu].data1,

			err_data_buffer[cpu].data2,

			err_data_buffer[cpu].data3);

}

static ssize_t

store_err_data_buffer(struct sys_device *dev, const char *buf, size_t size)

{

	unsigned int cpu=dev->id;

	int ret;

#ifdef ERR_INJ_DEBUG

	printk("write err_data_buffer=[%lx,%lx,%lx] on cpu%d\n",

		 err_data_buffer[cpu].data1,

		 err_data_buffer[cpu].data2,

		 err_data_buffer[cpu].data3,

		 cpu);

#endif

	ret=sscanf(buf, "%lx, %lx, %lx",

			&err_data_buffer[cpu].data1,

			&err_data_buffer[cpu].data2,

			&err_data_buffer[cpu].data3);

	if (ret!=ERR_DATA_BUFFER_SIZE)

		return -EINVAL;

	return size;

}

show(status)

show(capabilities)

show(resources)

define_one_rw(call_start);

define_one_rw(err_type_info);

define_one_rw(err_struct_info);

define_one_rw(err_data_buffer);

define_one_rw(virtual_to_phys);

define_one_ro(status);

define_one_ro(capabilities);

define_one_ro(resources);

static struct attribute *default_attrs[] = {

	&attr_call_start.attr,

	&attr_virtual_to_phys.attr,

	&attr_err_type_info.attr,

	&attr_err_struct_info.attr,

	&attr_err_data_buffer.attr,

	&attr_status.attr,

	&attr_capabilities.attr,

	&attr_resources.attr,

	NULL

};

static struct attribute_group err_inject_attr_group = {

	.attrs = default_attrs,

	.name = "err_inject"

};

/* Add/Remove err_inject interface for CPU device */

static int __cpuinit err_inject_add_dev(struct sys_device * sys_dev)

{

	return sysfs_create_group(&sys_dev->kobj, &err_inject_attr_group);

}

static int __cpuinit err_inject_remove_dev(struct sys_device * sys_dev)

{

	sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);

	return 0;

}

static int __cpuinit err_inject_cpu_callback(struct notifier_block *nfb,

		unsigned long action, void *hcpu)

{

	unsigned int cpu = (unsigned long)hcpu;

	struct sys_device *sys_dev;

	sys_dev = get_cpu_sysdev(cpu);

	switch (action) {

	case CPU_ONLINE:

		err_inject_add_dev(sys_dev);

		break;

	case CPU_DEAD:

		err_inject_remove_dev(sys_dev);

		break;

	}

	return NOTIFY_OK;

}

static struct notifier_block __cpuinitdata err_inject_cpu_notifier =

{

	.notifier_call = err_inject_cpu_callback,

};

static int __init

err_inject_init(void)

{

	int i;

#ifdef ERR_INJ_DEBUG

	printk(KERN_INFO "Enter error injection driver.\n");

#endif

	for_each_online_cpu(i) {

		err_inject_cpu_callback(&err_inject_cpu_notifier, CPU_ONLINE,

				(void *)(long)i);

	}

	register_hotcpu_notifier(&err_inject_cpu_notifier);

	return 0;

}

static void __exit

err_inject_exit(void)

{

	int i;

	struct sys_device *sys_dev;

#ifdef ERR_INJ_DEBUG

	printk(KERN_INFO "Exit error injection driver.\n");

#endif

	for_each_online_cpu(i) {

		sys_dev = get_cpu_sysdev(i);

		sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);

	}

	unregister_hotcpu_notifier(&err_inject_cpu_notifier);

}

module_init(err_inject_init);

module_exit(err_inject_exit);

MODULE_AUTHOR("Fenghua Yu <fenghua.yu@intel.com>");

MODULE_DESCRIPTION("MC error injection kenrel sysfs interface");

MODULE_LICENSE("GPL");