ia64/linux-2.6.18-xen.hg

view drivers/macintosh/windfarm_cpufreq_clamp.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 #include <linux/types.h>
2 #include <linux/errno.h>
3 #include <linux/kernel.h>
4 #include <linux/delay.h>
5 #include <linux/slab.h>
6 #include <linux/init.h>
7 #include <linux/wait.h>
8 #include <linux/cpufreq.h>
10 #include <asm/prom.h>
12 #include "windfarm.h"
14 #define VERSION "0.3"
16 static int clamped;
17 static struct wf_control *clamp_control;
19 static int clamp_notifier_call(struct notifier_block *self,
20 unsigned long event, void *data)
21 {
22 struct cpufreq_policy *p = data;
23 unsigned long max_freq;
25 if (event != CPUFREQ_ADJUST)
26 return 0;
28 max_freq = clamped ? (p->cpuinfo.min_freq) : (p->cpuinfo.max_freq);
29 cpufreq_verify_within_limits(p, 0, max_freq);
31 return 0;
32 }
34 static struct notifier_block clamp_notifier = {
35 .notifier_call = clamp_notifier_call,
36 };
38 static int clamp_set(struct wf_control *ct, s32 value)
39 {
40 if (value)
41 printk(KERN_INFO "windfarm: Clamping CPU frequency to "
42 "minimum !\n");
43 else
44 printk(KERN_INFO "windfarm: CPU frequency unclamped !\n");
45 clamped = value;
46 cpufreq_update_policy(0);
47 return 0;
48 }
50 static int clamp_get(struct wf_control *ct, s32 *value)
51 {
52 *value = clamped;
53 return 0;
54 }
56 static s32 clamp_min(struct wf_control *ct)
57 {
58 return 0;
59 }
61 static s32 clamp_max(struct wf_control *ct)
62 {
63 return 1;
64 }
66 static struct wf_control_ops clamp_ops = {
67 .set_value = clamp_set,
68 .get_value = clamp_get,
69 .get_min = clamp_min,
70 .get_max = clamp_max,
71 .owner = THIS_MODULE,
72 };
74 static int __init wf_cpufreq_clamp_init(void)
75 {
76 struct wf_control *clamp;
78 /* Don't register on old machines that use therm_pm72 for now */
79 if (machine_is_compatible("PowerMac7,2") ||
80 machine_is_compatible("PowerMac7,3") ||
81 machine_is_compatible("RackMac3,1"))
82 return -ENODEV;
84 clamp = kmalloc(sizeof(struct wf_control), GFP_KERNEL);
85 if (clamp == NULL)
86 return -ENOMEM;
87 cpufreq_register_notifier(&clamp_notifier, CPUFREQ_POLICY_NOTIFIER);
88 clamp->ops = &clamp_ops;
89 clamp->name = "cpufreq-clamp";
90 if (wf_register_control(clamp))
91 goto fail;
92 clamp_control = clamp;
93 return 0;
94 fail:
95 kfree(clamp);
96 return -ENODEV;
97 }
99 static void __exit wf_cpufreq_clamp_exit(void)
100 {
101 if (clamp_control)
102 wf_unregister_control(clamp_control);
103 }
106 module_init(wf_cpufreq_clamp_init);
107 module_exit(wf_cpufreq_clamp_exit);
109 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
110 MODULE_DESCRIPTION("CPU frequency clamp for PowerMacs thermal control");
111 MODULE_LICENSE("GPL");