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) 						\
38 static DEVICE_ATTR(name, 0444, show_##name, NULL)
39 
40 #define define_one_rw(name) 						\
41 static DEVICE_ATTR(name, 0644, show_##name, store_##name)
42 
43 static u64 call_start[NR_CPUS];
44 static u64 phys_addr[NR_CPUS];
45 static u64 err_type_info[NR_CPUS];
46 static u64 err_struct_info[NR_CPUS];
47 static struct {
48 	u64 data1;
49 	u64 data2;
50 	u64 data3;
51 } __attribute__((__aligned__(16))) err_data_buffer[NR_CPUS];
52 static s64 status[NR_CPUS];
53 static u64 capabilities[NR_CPUS];
54 static u64 resources[NR_CPUS];
55 
56 #define show(name) 							\
57 static ssize_t 								\
58 show_##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)							\
66 static ssize_t 								\
67 store_##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 
show(call_start)75 show(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  */
80 static ssize_t
81 store_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 
126 show(err_type_info)
store(err_type_info)127 store(err_type_info)
128 
129 static ssize_t
130 show_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 
137 static ssize_t
store_virtual_to_phys(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)138 store_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 
158 show(err_struct_info)
store(err_struct_info)159 store(err_struct_info)
160 
161 static ssize_t
162 show_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 
173 static ssize_t
store_err_data_buffer(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)174 store_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 
198 show(status)
199 show(capabilities)
200 show(resources)
201 
202 define_one_rw(call_start);
203 define_one_rw(err_type_info);
204 define_one_rw(err_struct_info);
205 define_one_rw(err_data_buffer);
206 define_one_rw(virtual_to_phys);
207 define_one_ro(status);
208 define_one_ro(capabilities);
209 define_one_ro(resources);
210 
211 static 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 
223 static 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 */
err_inject_add_dev(struct device * sys_dev)228 static int __cpuinit err_inject_add_dev(struct device * sys_dev)
229 {
230 	return sysfs_create_group(&sys_dev->kobj, &err_inject_attr_group);
231 }
232 
err_inject_remove_dev(struct device * sys_dev)233 static int __cpuinit err_inject_remove_dev(struct device * sys_dev)
234 {
235 	sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
236 	return 0;
237 }
err_inject_cpu_callback(struct notifier_block * nfb,unsigned long action,void * hcpu)238 static int __cpuinit 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 
259 static struct notifier_block __cpuinitdata err_inject_cpu_notifier =
260 {
261 	.notifier_call = err_inject_cpu_callback,
262 };
263 
264 static int __init
err_inject_init(void)265 err_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 	for_each_online_cpu(i) {
273 		err_inject_cpu_callback(&err_inject_cpu_notifier, CPU_ONLINE,
274 				(void *)(long)i);
275 	}
276 
277 	register_hotcpu_notifier(&err_inject_cpu_notifier);
278 
279 	return 0;
280 }
281 
282 static void __exit
err_inject_exit(void)283 err_inject_exit(void)
284 {
285 	int i;
286 	struct device *sys_dev;
287 
288 #ifdef ERR_INJ_DEBUG
289 	printk(KERN_INFO "Exit error injection driver.\n");
290 #endif
291 	for_each_online_cpu(i) {
292 		sys_dev = get_cpu_device(i);
293 		sysfs_remove_group(&sys_dev->kobj, &err_inject_attr_group);
294 	}
295 	unregister_hotcpu_notifier(&err_inject_cpu_notifier);
296 }
297 
298 module_init(err_inject_init);
299 module_exit(err_inject_exit);
300 
301 MODULE_AUTHOR("Fenghua Yu <fenghua.yu@intel.com>");
302 MODULE_DESCRIPTION("MC error injection kernel sysfs interface");
303 MODULE_LICENSE("GPL");
304