1/*
2 * err_inject.c -
3 *	1.) Inject errors to a processor.
4 *	2.) Query error injection capabilities.
5 * This driver along with user space code can be acting as an error
6 * injection tool.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
16 * NON INFRINGEMENT.  See the GNU General Public License for more
17 * details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 *
23 * Written by: Fenghua Yu <fenghua.yu@intel.com>, Intel Corporation
24 * Copyright (C) 2006, Intel Corp.  All rights reserved.
25 *
26 */
27#include <linux/device.h>
28#include <linux/init.h>
29#include <linux/mm.h>
30#include <linux/cpu.h>
31#include <linux/module.h>
32
33#define ERR_INJ_DEBUG
34
35#define ERR_DATA_BUFFER_SIZE 3 		// Three 8-byte;
36
37#define define_one_ro(name) 						\
38static DEVICE_ATTR(name, 0444, show_##name, NULL)
39
40#define define_one_rw(name) 						\
41static DEVICE_ATTR(name, 0644, show_##name, store_##name)
42
43static u64 call_start[NR_CPUS];
44static u64 phys_addr[NR_CPUS];
45static u64 err_type_info[NR_CPUS];
46static u64 err_struct_info[NR_CPUS];
47static struct {
48	u64 data1;
49	u64 data2;
50	u64 data3;
51} __attribute__((__aligned__(16))) err_data_buffer[NR_CPUS];
52static s64 status[NR_CPUS];
53static u64 capabilities[NR_CPUS];
54static u64 resources[NR_CPUS];
55
56#define show(name) 							\
57static ssize_t 								\
58show_##name(struct device *dev, struct device_attribute *attr,	\
59		char *buf)						\
60{									\
61	u32 cpu=dev->id;						\
62	return sprintf(buf, "%lx\n", name[cpu]);			\
63}
64
65#define store(name)							\
66static ssize_t 								\
67store_##name(struct device *dev, struct device_attribute *attr,	\
68					const char *buf, size_t size)	\
69{									\
70	unsigned int cpu=dev->id;					\
71	name[cpu] = simple_strtoull(buf, NULL, 16);			\
72	return size;							\
73}
74
75show(call_start)
76
77/* It's user's responsibility to call the PAL procedure on a specific
78 * processor. The cpu number in driver is only used for storing data.
79 */
80static ssize_t
81store_call_start(struct device *dev, struct device_attribute *attr,
82		const char *buf, size_t size)
83{
84	unsigned int cpu=dev->id;
85	unsigned long call_start = simple_strtoull(buf, NULL, 16);
86
87#ifdef ERR_INJ_DEBUG
88	printk(KERN_DEBUG "pal_mc_err_inject for cpu%d:\n", cpu);
89	printk(KERN_DEBUG "err_type_info=%lx,\n", err_type_info[cpu]);
90	printk(KERN_DEBUG "err_struct_info=%lx,\n", err_struct_info[cpu]);
91	printk(KERN_DEBUG "err_data_buffer=%lx, %lx, %lx.\n",
92			  err_data_buffer[cpu].data1,
93			  err_data_buffer[cpu].data2,
94			  err_data_buffer[cpu].data3);
95#endif
96	switch (call_start) {
97	    case 0: /* Do nothing. */
98		break;
99	    case 1: /* Call pal_mc_error_inject in physical mode. */
100		status[cpu]=ia64_pal_mc_error_inject_phys(err_type_info[cpu],
101					err_struct_info[cpu],
102					ia64_tpa(&err_data_buffer[cpu]),
103					&capabilities[cpu],
104			 		&resources[cpu]);
105		break;
106	    case 2: /* Call pal_mc_error_inject in virtual mode. */
107		status[cpu]=ia64_pal_mc_error_inject_virt(err_type_info[cpu],
108					err_struct_info[cpu],
109					ia64_tpa(&err_data_buffer[cpu]),
110					&capabilities[cpu],
111			 		&resources[cpu]);
112		break;
113	    default:
114		status[cpu] = -EINVAL;
115		break;
116	}
117
118#ifdef ERR_INJ_DEBUG
119	printk(KERN_DEBUG "Returns: status=%d,\n", (int)status[cpu]);
120	printk(KERN_DEBUG "capapbilities=%lx,\n", capabilities[cpu]);
121	printk(KERN_DEBUG "resources=%lx\n", resources[cpu]);
122#endif
123	return size;
124}
125
126show(err_type_info)
127store(err_type_info)
128
129static ssize_t
130show_virtual_to_phys(struct device *dev, struct device_attribute *attr,
131			char *buf)
132{
133	unsigned int cpu=dev->id;
134	return sprintf(buf, "%lx\n", phys_addr[cpu]);
135}
136
137static ssize_t
138store_virtual_to_phys(struct device *dev, struct device_attribute *attr,
139			const char *buf, size_t size)
140{
141	unsigned int cpu=dev->id;
142	u64 virt_addr=simple_strtoull(buf, NULL, 16);
143	int ret;
144
145        ret = get_user_pages(current, current->mm, virt_addr,
146                        1, VM_READ, 0, NULL, NULL);
147	if (ret<=0) {
148#ifdef ERR_INJ_DEBUG
149		printk("Virtual address %lx is not existing.\n",virt_addr);
150#endif
151		return -EINVAL;
152	}
153
154	phys_addr[cpu] = ia64_tpa(virt_addr);
155	return size;
156}
157
158show(err_struct_info)
159store(err_struct_info)
160
161static ssize_t
162show_err_data_buffer(struct device *dev,
163			struct device_attribute *attr, char *buf)
164{
165	unsigned int cpu=dev->id;
166
167	return sprintf(buf, "%lx, %lx, %lx\n",
168			err_data_buffer[cpu].data1,
169			err_data_buffer[cpu].data2,
170			err_data_buffer[cpu].data3);
171}
172
173static ssize_t
174store_err_data_buffer(struct device *dev,
175			struct device_attribute *attr,
176			const char *buf, size_t size)
177{
178	unsigned int cpu=dev->id;
179	int ret;
180
181#ifdef ERR_INJ_DEBUG
182	printk("write err_data_buffer=[%lx,%lx,%lx] on cpu%d\n",
183		 err_data_buffer[cpu].data1,
184		 err_data_buffer[cpu].data2,
185		 err_data_buffer[cpu].data3,
186		 cpu);
187#endif
188	ret=sscanf(buf, "%lx, %lx, %lx",
189			&err_data_buffer[cpu].data1,
190			&err_data_buffer[cpu].data2,
191			&err_data_buffer[cpu].data3);
192	if (ret!=ERR_DATA_BUFFER_SIZE)
193		return -EINVAL;
194
195	return size;
196}
197
198show(status)
199show(capabilities)
200show(resources)
201
202define_one_rw(call_start);
203define_one_rw(err_type_info);
204define_one_rw(err_struct_info);
205define_one_rw(err_data_buffer);
206define_one_rw(virtual_to_phys);
207define_one_ro(status);
208define_one_ro(capabilities);
209define_one_ro(resources);
210
211static struct attribute *default_attrs[] = {
212	&dev_attr_call_start.attr,
213	&dev_attr_virtual_to_phys.attr,
214	&dev_attr_err_type_info.attr,
215	&dev_attr_err_struct_info.attr,
216	&dev_attr_err_data_buffer.attr,
217	&dev_attr_status.attr,
218	&dev_attr_capabilities.attr,
219	&dev_attr_resources.attr,
220	NULL
221};
222
223static struct attribute_group err_inject_attr_group = {
224	.attrs = default_attrs,
225	.name = "err_inject"
226};
227/* Add/Remove err_inject interface for CPU device */
228static int err_inject_add_dev(struct device *sys_dev)
229{
230	return sysfs_create_group(&sys_dev->kobj, &err_inject_attr_group);
231}
232
233static int err_inject_remove_dev(struct device *sys_dev)
234{
235	sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
236	return 0;
237}
238static int err_inject_cpu_callback(struct notifier_block *nfb,
239		unsigned long action, void *hcpu)
240{
241	unsigned int cpu = (unsigned long)hcpu;
242	struct device *sys_dev;
243
244	sys_dev = get_cpu_device(cpu);
245	switch (action) {
246	case CPU_ONLINE:
247	case CPU_ONLINE_FROZEN:
248		err_inject_add_dev(sys_dev);
249		break;
250	case CPU_DEAD:
251	case CPU_DEAD_FROZEN:
252		err_inject_remove_dev(sys_dev);
253		break;
254	}
255
256	return NOTIFY_OK;
257}
258
259static struct notifier_block err_inject_cpu_notifier =
260{
261	.notifier_call = err_inject_cpu_callback,
262};
263
264static int __init
265err_inject_init(void)
266{
267	int i;
268
269#ifdef ERR_INJ_DEBUG
270	printk(KERN_INFO "Enter error injection driver.\n");
271#endif
272
273	cpu_notifier_register_begin();
274
275	for_each_online_cpu(i) {
276		err_inject_cpu_callback(&err_inject_cpu_notifier, CPU_ONLINE,
277				(void *)(long)i);
278	}
279
280	__register_hotcpu_notifier(&err_inject_cpu_notifier);
281
282	cpu_notifier_register_done();
283
284	return 0;
285}
286
287static void __exit
288err_inject_exit(void)
289{
290	int i;
291	struct device *sys_dev;
292
293#ifdef ERR_INJ_DEBUG
294	printk(KERN_INFO "Exit error injection driver.\n");
295#endif
296
297	cpu_notifier_register_begin();
298
299	for_each_online_cpu(i) {
300		sys_dev = get_cpu_device(i);
301		sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
302	}
303
304	__unregister_hotcpu_notifier(&err_inject_cpu_notifier);
305
306	cpu_notifier_register_done();
307}
308
309module_init(err_inject_init);
310module_exit(err_inject_exit);
311
312MODULE_AUTHOR("Fenghua Yu <fenghua.yu@intel.com>");
313MODULE_DESCRIPTION("MC error injection kernel sysfs interface");
314MODULE_LICENSE("GPL");
315