diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpuid.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/kernel/cpuid.c')
-rw-r--r-- | arch/i386/kernel/cpuid.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpuid.c b/arch/i386/kernel/cpuid.c new file mode 100644 index 000000000000..2e2756345bb2 --- /dev/null +++ b/arch/i386/kernel/cpuid.c | |||
@@ -0,0 +1,246 @@ | |||
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 | #include <linux/config.h> | ||
28 | |||
29 | #include <linux/types.h> | ||
30 | #include <linux/errno.h> | ||
31 | #include <linux/fcntl.h> | ||
32 | #include <linux/init.h> | ||
33 | #include <linux/poll.h> | ||
34 | #include <linux/smp.h> | ||
35 | #include <linux/major.h> | ||
36 | #include <linux/fs.h> | ||
37 | #include <linux/smp_lock.h> | ||
38 | #include <linux/fs.h> | ||
39 | #include <linux/device.h> | ||
40 | #include <linux/cpu.h> | ||
41 | #include <linux/notifier.h> | ||
42 | |||
43 | #include <asm/processor.h> | ||
44 | #include <asm/msr.h> | ||
45 | #include <asm/uaccess.h> | ||
46 | #include <asm/system.h> | ||
47 | |||
48 | static struct class_simple *cpuid_class; | ||
49 | |||
50 | #ifdef CONFIG_SMP | ||
51 | |||
52 | struct cpuid_command { | ||
53 | int cpu; | ||
54 | u32 reg; | ||
55 | u32 *data; | ||
56 | }; | ||
57 | |||
58 | static void cpuid_smp_cpuid(void *cmd_block) | ||
59 | { | ||
60 | struct cpuid_command *cmd = (struct cpuid_command *)cmd_block; | ||
61 | |||
62 | if (cmd->cpu == smp_processor_id()) | ||
63 | cpuid(cmd->reg, &cmd->data[0], &cmd->data[1], &cmd->data[2], | ||
64 | &cmd->data[3]); | ||
65 | } | ||
66 | |||
67 | static inline void do_cpuid(int cpu, u32 reg, u32 * data) | ||
68 | { | ||
69 | struct cpuid_command cmd; | ||
70 | |||
71 | preempt_disable(); | ||
72 | if (cpu == smp_processor_id()) { | ||
73 | cpuid(reg, &data[0], &data[1], &data[2], &data[3]); | ||
74 | } else { | ||
75 | cmd.cpu = cpu; | ||
76 | cmd.reg = reg; | ||
77 | cmd.data = data; | ||
78 | |||
79 | smp_call_function(cpuid_smp_cpuid, &cmd, 1, 1); | ||
80 | } | ||
81 | preempt_enable(); | ||
82 | } | ||
83 | #else /* ! CONFIG_SMP */ | ||
84 | |||
85 | static inline void do_cpuid(int cpu, u32 reg, u32 * data) | ||
86 | { | ||
87 | cpuid(reg, &data[0], &data[1], &data[2], &data[3]); | ||
88 | } | ||
89 | |||
90 | #endif /* ! CONFIG_SMP */ | ||
91 | |||
92 | static loff_t cpuid_seek(struct file *file, loff_t offset, int orig) | ||
93 | { | ||
94 | loff_t ret; | ||
95 | |||
96 | lock_kernel(); | ||
97 | |||
98 | switch (orig) { | ||
99 | case 0: | ||
100 | file->f_pos = offset; | ||
101 | ret = file->f_pos; | ||
102 | break; | ||
103 | case 1: | ||
104 | file->f_pos += offset; | ||
105 | ret = file->f_pos; | ||
106 | break; | ||
107 | default: | ||
108 | ret = -EINVAL; | ||
109 | } | ||
110 | |||
111 | unlock_kernel(); | ||
112 | return ret; | ||
113 | } | ||
114 | |||
115 | static ssize_t cpuid_read(struct file *file, char __user *buf, | ||
116 | size_t count, loff_t * ppos) | ||
117 | { | ||
118 | char __user *tmp = buf; | ||
119 | u32 data[4]; | ||
120 | size_t rv; | ||
121 | u32 reg = *ppos; | ||
122 | int cpu = iminor(file->f_dentry->d_inode); | ||
123 | |||
124 | if (count % 16) | ||
125 | return -EINVAL; /* Invalid chunk size */ | ||
126 | |||
127 | for (rv = 0; count; count -= 16) { | ||
128 | do_cpuid(cpu, reg, data); | ||
129 | if (copy_to_user(tmp, &data, 16)) | ||
130 | return -EFAULT; | ||
131 | tmp += 16; | ||
132 | *ppos = reg++; | ||
133 | } | ||
134 | |||
135 | return tmp - buf; | ||
136 | } | ||
137 | |||
138 | static int cpuid_open(struct inode *inode, struct file *file) | ||
139 | { | ||
140 | unsigned int cpu = iminor(file->f_dentry->d_inode); | ||
141 | struct cpuinfo_x86 *c = &(cpu_data)[cpu]; | ||
142 | |||
143 | if (cpu >= NR_CPUS || !cpu_online(cpu)) | ||
144 | return -ENXIO; /* No such CPU */ | ||
145 | if (c->cpuid_level < 0) | ||
146 | return -EIO; /* CPUID not supported */ | ||
147 | |||
148 | return 0; | ||
149 | } | ||
150 | |||
151 | /* | ||
152 | * File operations we support | ||
153 | */ | ||
154 | static struct file_operations cpuid_fops = { | ||
155 | .owner = THIS_MODULE, | ||
156 | .llseek = cpuid_seek, | ||
157 | .read = cpuid_read, | ||
158 | .open = cpuid_open, | ||
159 | }; | ||
160 | |||
161 | static int cpuid_class_simple_device_add(int i) | ||
162 | { | ||
163 | int err = 0; | ||
164 | struct class_device *class_err; | ||
165 | |||
166 | class_err = class_simple_device_add(cpuid_class, MKDEV(CPUID_MAJOR, i), NULL, "cpu%d",i); | ||
167 | if (IS_ERR(class_err)) | ||
168 | err = PTR_ERR(class_err); | ||
169 | return err; | ||
170 | } | ||
171 | |||
172 | static int __devinit cpuid_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) | ||
173 | { | ||
174 | unsigned int cpu = (unsigned long)hcpu; | ||
175 | |||
176 | switch (action) { | ||
177 | case CPU_ONLINE: | ||
178 | cpuid_class_simple_device_add(cpu); | ||
179 | break; | ||
180 | case CPU_DEAD: | ||
181 | class_simple_device_remove(MKDEV(CPUID_MAJOR, cpu)); | ||
182 | break; | ||
183 | } | ||
184 | return NOTIFY_OK; | ||
185 | } | ||
186 | |||
187 | static struct notifier_block cpuid_class_cpu_notifier = | ||
188 | { | ||
189 | .notifier_call = cpuid_class_cpu_callback, | ||
190 | }; | ||
191 | |||
192 | static int __init cpuid_init(void) | ||
193 | { | ||
194 | int i, err = 0; | ||
195 | i = 0; | ||
196 | |||
197 | if (register_chrdev(CPUID_MAJOR, "cpu/cpuid", &cpuid_fops)) { | ||
198 | printk(KERN_ERR "cpuid: unable to get major %d for cpuid\n", | ||
199 | CPUID_MAJOR); | ||
200 | err = -EBUSY; | ||
201 | goto out; | ||
202 | } | ||
203 | cpuid_class = class_simple_create(THIS_MODULE, "cpuid"); | ||
204 | if (IS_ERR(cpuid_class)) { | ||
205 | err = PTR_ERR(cpuid_class); | ||
206 | goto out_chrdev; | ||
207 | } | ||
208 | for_each_online_cpu(i) { | ||
209 | err = cpuid_class_simple_device_add(i); | ||
210 | if (err != 0) | ||
211 | goto out_class; | ||
212 | } | ||
213 | register_cpu_notifier(&cpuid_class_cpu_notifier); | ||
214 | |||
215 | err = 0; | ||
216 | goto out; | ||
217 | |||
218 | out_class: | ||
219 | i = 0; | ||
220 | for_each_online_cpu(i) { | ||
221 | class_simple_device_remove(MKDEV(CPUID_MAJOR, i)); | ||
222 | } | ||
223 | class_simple_destroy(cpuid_class); | ||
224 | out_chrdev: | ||
225 | unregister_chrdev(CPUID_MAJOR, "cpu/cpuid"); | ||
226 | out: | ||
227 | return err; | ||
228 | } | ||
229 | |||
230 | static void __exit cpuid_exit(void) | ||
231 | { | ||
232 | int cpu = 0; | ||
233 | |||
234 | for_each_online_cpu(cpu) | ||
235 | class_simple_device_remove(MKDEV(CPUID_MAJOR, cpu)); | ||
236 | class_simple_destroy(cpuid_class); | ||
237 | unregister_chrdev(CPUID_MAJOR, "cpu/cpuid"); | ||
238 | unregister_cpu_notifier(&cpuid_class_cpu_notifier); | ||
239 | } | ||
240 | |||
241 | module_init(cpuid_init); | ||
242 | module_exit(cpuid_exit); | ||
243 | |||
244 | MODULE_AUTHOR("H. Peter Anvin <hpa@zytor.com>"); | ||
245 | MODULE_DESCRIPTION("x86 generic CPUID driver"); | ||
246 | MODULE_LICENSE("GPL"); | ||