diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 05:17:01 -0400 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2007-10-11 05:17:01 -0400 |
commit | 9a163ed8e0552fdcffe405d2ea7134819a81456e (patch) | |
tree | b322fd2afbb812ba7ddfd22f3734aaab007c2aa5 /arch/x86/kernel/cpuid.c | |
parent | f7627e2513987bb5d4e8cb13c4e0a478352141ac (diff) |
i386: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpuid.c')
-rw-r--r-- | arch/x86/kernel/cpuid.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c new file mode 100644 index 000000000000..5c2faa10e9fa --- /dev/null +++ b/arch/x86/kernel/cpuid.c | |||
@@ -0,0 +1,242 @@ | |||
1 | /* ----------------------------------------------------------------------- * | ||
2 | * | ||
3 | * Copyright 2000 H. Peter Anvin - All Rights Reserved | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or modify | ||
6 | * it under the terms of the GNU General Public License as published by | ||
7 | * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139, | ||
8 | * USA; either version 2 of the License, or (at your option) any later | ||
9 | * version; incorporated herein by reference. | ||
10 | * | ||
11 | * ----------------------------------------------------------------------- */ | ||
12 | |||
13 | /* | ||
14 | * cpuid.c | ||
15 | * | ||
16 | * x86 CPUID access device | ||
17 | * | ||
18 | * This device is accessed by lseek() to the appropriate CPUID level | ||
19 | * and then read in chunks of 16 bytes. A larger size means multiple | ||
20 | * reads of consecutive levels. | ||
21 | * | ||
22 | * This driver uses /dev/cpu/%d/cpuid where %d is the minor number, and on | ||
23 | * an SMP box will direct the access to CPU %d. | ||
24 | */ | ||
25 | |||
26 | #include <linux/module.h> | ||
27 | |||
28 | #include <linux/types.h> | ||
29 | #include <linux/errno.h> | ||
30 | #include <linux/fcntl.h> | ||
31 | #include <linux/init.h> | ||
32 | #include <linux/poll.h> | ||
33 | #include <linux/smp.h> | ||
34 | #include <linux/major.h> | ||
35 | #include <linux/fs.h> | ||
36 | #include <linux/smp_lock.h> | ||
37 | #include <linux/device.h> | ||
38 | #include <linux/cpu.h> | ||
39 | #include <linux/notifier.h> | ||
40 | |||
41 | #include <asm/processor.h> | ||
42 | #include <asm/msr.h> | ||
43 | #include <asm/uaccess.h> | ||
44 | #include <asm/system.h> | ||
45 | |||
46 | static struct class *cpuid_class; | ||
47 | |||
48 | #ifdef CONFIG_SMP | ||
49 | |||
50 | struct cpuid_command { | ||
51 | u32 reg; | ||
52 | u32 *data; | ||
53 | }; | ||
54 | |||
55 | static void cpuid_smp_cpuid(void *cmd_block) | ||
56 | { | ||
57 | struct cpuid_command *cmd = (struct cpuid_command *)cmd_block; | ||
58 | |||
59 | cpuid(cmd->reg, &cmd->data[0], &cmd->data[1], &cmd->data[2], | ||
60 | &cmd->data[3]); | ||
61 | } | ||
62 | |||
63 | static inline void do_cpuid(int cpu, u32 reg, u32 * data) | ||
64 | { | ||
65 | struct cpuid_command cmd; | ||
66 | |||
67 | preempt_disable(); | ||
68 | if (cpu == smp_processor_id()) { | ||
69 | cpuid(reg, &data[0], &data[1], &data[2], &data[3]); | ||
70 | } else { | ||
71 | cmd.reg = reg; | ||
72 | cmd.data = data; | ||
73 | |||
74 | smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1); | ||
75 | } | ||
76 | preempt_enable(); | ||
77 | } | ||
78 | #else /* ! CONFIG_SMP */ | ||
79 | |||
80 | static inline void do_cpuid(int cpu, u32 reg, u32 * data) | ||
81 | { | ||
82 | cpuid(reg, &data[0], &data[1], &data[2], &data[3]); | ||
83 | } | ||
84 | |||
85 | #endif /* ! CONFIG_SMP */ | ||
86 | |||
87 | static loff_t cpuid_seek(struct file *file, loff_t offset, int orig) | ||
88 | { | ||
89 | loff_t ret; | ||
90 | |||
91 | lock_kernel(); | ||
92 | |||
93 | switch (orig) { | ||
94 | case 0: | ||
95 | file->f_pos = offset; | ||
96 | ret = file->f_pos; | ||
97 | break; | ||
98 | case 1: | ||
99 | file->f_pos += offset; | ||
100 | ret = file->f_pos; | ||
101 | break; | ||
102 | default: | ||
103 | ret = -EINVAL; | ||
104 | } | ||
105 | |||
106 | unlock_kernel(); | ||
107 | return ret; | ||
108 | } | ||
109 | |||
110 | static ssize_t cpuid_read(struct file *file, char __user *buf, | ||
111 | size_t count, loff_t * ppos) | ||
112 | { | ||
113 | char __user *tmp = buf; | ||
114 | u32 data[4]; | ||
115 | u32 reg = *ppos; | ||
116 | int cpu = iminor(file->f_path.dentry->d_inode); | ||
117 | |||
118 | if (count % 16) | ||
119 | return -EINVAL; /* Invalid chunk size */ | ||
120 | |||
121 | for (; count; count -= 16) { | ||
122 | do_cpuid(cpu, reg, data); | ||
123 | if (copy_to_user(tmp, &data, 16)) | ||
124 | return -EFAULT; | ||
125 | tmp += 16; | ||
126 | *ppos = reg++; | ||
127 | } | ||
128 | |||
129 | return tmp - buf; | ||
130 | } | ||
131 | |||
132 | static int cpuid_open(struct inode *inode, struct file *file) | ||
133 | { | ||
134 | unsigned int cpu = iminor(file->f_path.dentry->d_inode); | ||
135 | struct cpuinfo_x86 *c = &(cpu_data)[cpu]; | ||
136 | |||
137 | if (cpu >= NR_CPUS || !cpu_online(cpu)) | ||
138 | return -ENXIO; /* No such CPU */ | ||
139 | if (c->cpuid_level < 0) | ||
140 | return -EIO; /* CPUID not supported */ | ||
141 | |||
142 | return 0; | ||
143 | } | ||
144 | |||
145 | /* | ||
146 | * File operations we support | ||
147 | */ | ||
148 | static const struct file_operations cpuid_fops = { | ||
149 | .owner = THIS_MODULE, | ||
150 | .llseek = cpuid_seek, | ||
151 | .read = cpuid_read, | ||
152 | .open = cpuid_open, | ||
153 | }; | ||
154 | |||
155 | static int cpuid_device_create(int i) | ||
156 | { | ||
157 | int err = 0; | ||
158 | struct device *dev; | ||
159 | |||
160 | dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, i), "cpu%d",i); | ||
161 | if (IS_ERR(dev)) | ||
162 | err = PTR_ERR(dev); | ||
163 | return err; | ||
164 | } | ||
165 | |||
166 | static int cpuid_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) | ||
167 | { | ||
168 | unsigned int cpu = (unsigned long)hcpu; | ||
169 | |||
170 | switch (action) { | ||
171 | case CPU_ONLINE: | ||
172 | case CPU_ONLINE_FROZEN: | ||
173 | cpuid_device_create(cpu); | ||
174 | break; | ||
175 | case CPU_DEAD: | ||
176 | case CPU_DEAD_FROZEN: | ||
177 | device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu)); | ||
178 | break; | ||
179 | } | ||
180 | return NOTIFY_OK; | ||
181 | } | ||
182 | |||
183 | static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier = | ||
184 | { | ||
185 | .notifier_call = cpuid_class_cpu_callback, | ||
186 | }; | ||
187 | |||
188 | static int __init cpuid_init(void) | ||
189 | { | ||
190 | int i, err = 0; | ||
191 | i = 0; | ||
192 | |||
193 | if (register_chrdev(CPUID_MAJOR, "cpu/cpuid", &cpuid_fops)) { | ||
194 | printk(KERN_ERR "cpuid: unable to get major %d for cpuid\n", | ||
195 | CPUID_MAJOR); | ||
196 | err = -EBUSY; | ||
197 | goto out; | ||
198 | } | ||
199 | cpuid_class = class_create(THIS_MODULE, "cpuid"); | ||
200 | if (IS_ERR(cpuid_class)) { | ||
201 | err = PTR_ERR(cpuid_class); | ||
202 | goto out_chrdev; | ||
203 | } | ||
204 | for_each_online_cpu(i) { | ||
205 | err = cpuid_device_create(i); | ||
206 | if (err != 0) | ||
207 | goto out_class; | ||
208 | } | ||
209 | register_hotcpu_notifier(&cpuid_class_cpu_notifier); | ||
210 | |||
211 | err = 0; | ||
212 | goto out; | ||
213 | |||
214 | out_class: | ||
215 | i = 0; | ||
216 | for_each_online_cpu(i) { | ||
217 | device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, i)); | ||
218 | } | ||
219 | class_destroy(cpuid_class); | ||
220 | out_chrdev: | ||
221 | unregister_chrdev(CPUID_MAJOR, "cpu/cpuid"); | ||
222 | out: | ||
223 | return err; | ||
224 | } | ||
225 | |||
226 | static void __exit cpuid_exit(void) | ||
227 | { | ||
228 | int cpu = 0; | ||
229 | |||
230 | for_each_online_cpu(cpu) | ||
231 | device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu)); | ||
232 | class_destroy(cpuid_class); | ||
233 | unregister_chrdev(CPUID_MAJOR, "cpu/cpuid"); | ||
234 | unregister_hotcpu_notifier(&cpuid_class_cpu_notifier); | ||
235 | } | ||
236 | |||
237 | module_init(cpuid_init); | ||
238 | module_exit(cpuid_exit); | ||
239 | |||
240 | MODULE_AUTHOR("H. Peter Anvin <hpa@zytor.com>"); | ||
241 | MODULE_DESCRIPTION("x86 generic CPUID driver"); | ||
242 | MODULE_LICENSE("GPL"); | ||