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/sparc64/kernel/us3_cpufreq.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/sparc64/kernel/us3_cpufreq.c')
-rw-r--r-- | arch/sparc64/kernel/us3_cpufreq.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/us3_cpufreq.c b/arch/sparc64/kernel/us3_cpufreq.c new file mode 100644 index 000000000000..18fe54b8aa55 --- /dev/null +++ b/arch/sparc64/kernel/us3_cpufreq.c | |||
@@ -0,0 +1,255 @@ | |||
1 | /* us3_cpufreq.c: UltraSPARC-III cpu frequency support | ||
2 | * | ||
3 | * Copyright (C) 2003 David S. Miller (davem@redhat.com) | ||
4 | * | ||
5 | * Many thanks to Dominik Brodowski for fixing up the cpufreq | ||
6 | * infrastructure in order to make this driver easier to implement. | ||
7 | */ | ||
8 | |||
9 | #include <linux/kernel.h> | ||
10 | #include <linux/module.h> | ||
11 | #include <linux/sched.h> | ||
12 | #include <linux/smp.h> | ||
13 | #include <linux/cpufreq.h> | ||
14 | #include <linux/threads.h> | ||
15 | #include <linux/slab.h> | ||
16 | #include <linux/init.h> | ||
17 | |||
18 | #include <asm/head.h> | ||
19 | #include <asm/timer.h> | ||
20 | |||
21 | static struct cpufreq_driver *cpufreq_us3_driver; | ||
22 | |||
23 | struct us3_freq_percpu_info { | ||
24 | struct cpufreq_frequency_table table[4]; | ||
25 | }; | ||
26 | |||
27 | /* Indexed by cpu number. */ | ||
28 | static struct us3_freq_percpu_info *us3_freq_table; | ||
29 | |||
30 | /* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled | ||
31 | * in the Safari config register. | ||
32 | */ | ||
33 | #define SAFARI_CFG_DIV_1 0x0000000000000000UL | ||
34 | #define SAFARI_CFG_DIV_2 0x0000000040000000UL | ||
35 | #define SAFARI_CFG_DIV_32 0x0000000080000000UL | ||
36 | #define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL | ||
37 | |||
38 | static unsigned long read_safari_cfg(void) | ||
39 | { | ||
40 | unsigned long ret; | ||
41 | |||
42 | __asm__ __volatile__("ldxa [%%g0] %1, %0" | ||
43 | : "=&r" (ret) | ||
44 | : "i" (ASI_SAFARI_CONFIG)); | ||
45 | return ret; | ||
46 | } | ||
47 | |||
48 | static void write_safari_cfg(unsigned long val) | ||
49 | { | ||
50 | __asm__ __volatile__("stxa %0, [%%g0] %1\n\t" | ||
51 | "membar #Sync" | ||
52 | : /* no outputs */ | ||
53 | : "r" (val), "i" (ASI_SAFARI_CONFIG) | ||
54 | : "memory"); | ||
55 | } | ||
56 | |||
57 | static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg) | ||
58 | { | ||
59 | unsigned long clock_tick = sparc64_get_clock_tick(cpu); | ||
60 | unsigned long ret; | ||
61 | |||
62 | switch (safari_cfg & SAFARI_CFG_DIV_MASK) { | ||
63 | case SAFARI_CFG_DIV_1: | ||
64 | ret = clock_tick / 1; | ||
65 | break; | ||
66 | case SAFARI_CFG_DIV_2: | ||
67 | ret = clock_tick / 2; | ||
68 | break; | ||
69 | case SAFARI_CFG_DIV_32: | ||
70 | ret = clock_tick / 32; | ||
71 | break; | ||
72 | default: | ||
73 | BUG(); | ||
74 | }; | ||
75 | |||
76 | return ret; | ||
77 | } | ||
78 | |||
79 | static void us3_set_cpu_divider_index(unsigned int cpu, unsigned int index) | ||
80 | { | ||
81 | unsigned long new_bits, new_freq, reg; | ||
82 | cpumask_t cpus_allowed; | ||
83 | struct cpufreq_freqs freqs; | ||
84 | |||
85 | if (!cpu_online(cpu)) | ||
86 | return; | ||
87 | |||
88 | cpus_allowed = current->cpus_allowed; | ||
89 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | ||
90 | |||
91 | new_freq = sparc64_get_clock_tick(cpu); | ||
92 | switch (index) { | ||
93 | case 0: | ||
94 | new_bits = SAFARI_CFG_DIV_1; | ||
95 | new_freq /= 1; | ||
96 | break; | ||
97 | case 1: | ||
98 | new_bits = SAFARI_CFG_DIV_2; | ||
99 | new_freq /= 2; | ||
100 | break; | ||
101 | case 2: | ||
102 | new_bits = SAFARI_CFG_DIV_32; | ||
103 | new_freq /= 32; | ||
104 | break; | ||
105 | |||
106 | default: | ||
107 | BUG(); | ||
108 | }; | ||
109 | |||
110 | reg = read_safari_cfg(); | ||
111 | |||
112 | freqs.old = get_current_freq(cpu, reg); | ||
113 | freqs.new = new_freq; | ||
114 | freqs.cpu = cpu; | ||
115 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | ||
116 | |||
117 | reg &= ~SAFARI_CFG_DIV_MASK; | ||
118 | reg |= new_bits; | ||
119 | write_safari_cfg(reg); | ||
120 | |||
121 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | ||
122 | |||
123 | set_cpus_allowed(current, cpus_allowed); | ||
124 | } | ||
125 | |||
126 | static int us3_freq_target(struct cpufreq_policy *policy, | ||
127 | unsigned int target_freq, | ||
128 | unsigned int relation) | ||
129 | { | ||
130 | unsigned int new_index = 0; | ||
131 | |||
132 | if (cpufreq_frequency_table_target(policy, | ||
133 | &us3_freq_table[policy->cpu].table[0], | ||
134 | target_freq, | ||
135 | relation, | ||
136 | &new_index)) | ||
137 | return -EINVAL; | ||
138 | |||
139 | us3_set_cpu_divider_index(policy->cpu, new_index); | ||
140 | |||
141 | return 0; | ||
142 | } | ||
143 | |||
144 | static int us3_freq_verify(struct cpufreq_policy *policy) | ||
145 | { | ||
146 | return cpufreq_frequency_table_verify(policy, | ||
147 | &us3_freq_table[policy->cpu].table[0]); | ||
148 | } | ||
149 | |||
150 | static int __init us3_freq_cpu_init(struct cpufreq_policy *policy) | ||
151 | { | ||
152 | unsigned int cpu = policy->cpu; | ||
153 | unsigned long clock_tick = sparc64_get_clock_tick(cpu); | ||
154 | struct cpufreq_frequency_table *table = | ||
155 | &us3_freq_table[cpu].table[0]; | ||
156 | |||
157 | table[0].index = 0; | ||
158 | table[0].frequency = clock_tick / 1; | ||
159 | table[1].index = 1; | ||
160 | table[1].frequency = clock_tick / 2; | ||
161 | table[2].index = 2; | ||
162 | table[2].frequency = clock_tick / 32; | ||
163 | table[3].index = 0; | ||
164 | table[3].frequency = CPUFREQ_TABLE_END; | ||
165 | |||
166 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | ||
167 | policy->cpuinfo.transition_latency = 0; | ||
168 | policy->cur = clock_tick; | ||
169 | |||
170 | return cpufreq_frequency_table_cpuinfo(policy, table); | ||
171 | } | ||
172 | |||
173 | static int us3_freq_cpu_exit(struct cpufreq_policy *policy) | ||
174 | { | ||
175 | if (cpufreq_us3_driver) | ||
176 | us3_set_cpu_divider_index(policy->cpu, 0); | ||
177 | |||
178 | return 0; | ||
179 | } | ||
180 | |||
181 | static int __init us3_freq_init(void) | ||
182 | { | ||
183 | unsigned long manuf, impl, ver; | ||
184 | int ret; | ||
185 | |||
186 | __asm__("rdpr %%ver, %0" : "=r" (ver)); | ||
187 | manuf = ((ver >> 48) & 0xffff); | ||
188 | impl = ((ver >> 32) & 0xffff); | ||
189 | |||
190 | if (manuf == CHEETAH_MANUF && | ||
191 | (impl == CHEETAH_IMPL || impl == CHEETAH_PLUS_IMPL)) { | ||
192 | struct cpufreq_driver *driver; | ||
193 | |||
194 | ret = -ENOMEM; | ||
195 | driver = kmalloc(sizeof(struct cpufreq_driver), GFP_KERNEL); | ||
196 | if (!driver) | ||
197 | goto err_out; | ||
198 | memset(driver, 0, sizeof(*driver)); | ||
199 | |||
200 | us3_freq_table = kmalloc( | ||
201 | (NR_CPUS * sizeof(struct us3_freq_percpu_info)), | ||
202 | GFP_KERNEL); | ||
203 | if (!us3_freq_table) | ||
204 | goto err_out; | ||
205 | |||
206 | memset(us3_freq_table, 0, | ||
207 | (NR_CPUS * sizeof(struct us3_freq_percpu_info))); | ||
208 | |||
209 | driver->verify = us3_freq_verify; | ||
210 | driver->target = us3_freq_target; | ||
211 | driver->init = us3_freq_cpu_init; | ||
212 | driver->exit = us3_freq_cpu_exit; | ||
213 | driver->owner = THIS_MODULE, | ||
214 | strcpy(driver->name, "UltraSPARC-III"); | ||
215 | |||
216 | cpufreq_us3_driver = driver; | ||
217 | ret = cpufreq_register_driver(driver); | ||
218 | if (ret) | ||
219 | goto err_out; | ||
220 | |||
221 | return 0; | ||
222 | |||
223 | err_out: | ||
224 | if (driver) { | ||
225 | kfree(driver); | ||
226 | cpufreq_us3_driver = NULL; | ||
227 | } | ||
228 | if (us3_freq_table) { | ||
229 | kfree(us3_freq_table); | ||
230 | us3_freq_table = NULL; | ||
231 | } | ||
232 | return ret; | ||
233 | } | ||
234 | |||
235 | return -ENODEV; | ||
236 | } | ||
237 | |||
238 | static void __exit us3_freq_exit(void) | ||
239 | { | ||
240 | if (cpufreq_us3_driver) { | ||
241 | cpufreq_unregister_driver(cpufreq_us3_driver); | ||
242 | |||
243 | kfree(cpufreq_us3_driver); | ||
244 | cpufreq_us3_driver = NULL; | ||
245 | kfree(us3_freq_table); | ||
246 | us3_freq_table = NULL; | ||
247 | } | ||
248 | } | ||
249 | |||
250 | MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); | ||
251 | MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III"); | ||
252 | MODULE_LICENSE("GPL"); | ||
253 | |||
254 | module_init(us3_freq_init); | ||
255 | module_exit(us3_freq_exit); | ||