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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
21static struct cpufreq_driver *cpufreq_us3_driver;
22
23struct us3_freq_percpu_info {
24 struct cpufreq_frequency_table table[4];
25};
26
27
28static struct us3_freq_percpu_info *us3_freq_table;
29
30
31
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
38static 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
48static void write_safari_cfg(unsigned long val)
49{
50 __asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
51 "membar #Sync"
52 :
53 : "r" (val), "i" (ASI_SAFARI_CONFIG)
54 : "memory");
55}
56
57static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
58{
59 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
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
79static unsigned int us3_freq_get(unsigned int cpu)
80{
81 cpumask_t cpus_allowed;
82 unsigned long reg;
83 unsigned int ret;
84
85 cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
86 set_cpus_allowed_ptr(current, cpumask_of(cpu));
87
88 reg = read_safari_cfg();
89 ret = get_current_freq(cpu, reg);
90
91 set_cpus_allowed_ptr(current, &cpus_allowed);
92
93 return ret;
94}
95
96static void us3_set_cpu_divider_index(struct cpufreq_policy *policy,
97 unsigned int index)
98{
99 unsigned int cpu = policy->cpu;
100 unsigned long new_bits, new_freq, reg;
101 cpumask_t cpus_allowed;
102 struct cpufreq_freqs freqs;
103
104 cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
105 set_cpus_allowed_ptr(current, cpumask_of(cpu));
106
107 new_freq = sparc64_get_clock_tick(cpu) / 1000;
108 switch (index) {
109 case 0:
110 new_bits = SAFARI_CFG_DIV_1;
111 new_freq /= 1;
112 break;
113 case 1:
114 new_bits = SAFARI_CFG_DIV_2;
115 new_freq /= 2;
116 break;
117 case 2:
118 new_bits = SAFARI_CFG_DIV_32;
119 new_freq /= 32;
120 break;
121
122 default:
123 BUG();
124 }
125
126 reg = read_safari_cfg();
127
128 freqs.old = get_current_freq(cpu, reg);
129 freqs.new = new_freq;
130 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
131
132 reg &= ~SAFARI_CFG_DIV_MASK;
133 reg |= new_bits;
134 write_safari_cfg(reg);
135
136 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
137
138 set_cpus_allowed_ptr(current, &cpus_allowed);
139}
140
141static int us3_freq_target(struct cpufreq_policy *policy,
142 unsigned int target_freq,
143 unsigned int relation)
144{
145 unsigned int new_index = 0;
146
147 if (cpufreq_frequency_table_target(policy,
148 &us3_freq_table[policy->cpu].table[0],
149 target_freq,
150 relation,
151 &new_index))
152 return -EINVAL;
153
154 us3_set_cpu_divider_index(policy, new_index);
155
156 return 0;
157}
158
159static int us3_freq_verify(struct cpufreq_policy *policy)
160{
161 return cpufreq_frequency_table_verify(policy,
162 &us3_freq_table[policy->cpu].table[0]);
163}
164
165static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
166{
167 unsigned int cpu = policy->cpu;
168 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
169 struct cpufreq_frequency_table *table =
170 &us3_freq_table[cpu].table[0];
171
172 table[0].index = 0;
173 table[0].frequency = clock_tick / 1;
174 table[1].index = 1;
175 table[1].frequency = clock_tick / 2;
176 table[2].index = 2;
177 table[2].frequency = clock_tick / 32;
178 table[3].index = 0;
179 table[3].frequency = CPUFREQ_TABLE_END;
180
181 policy->cpuinfo.transition_latency = 0;
182 policy->cur = clock_tick;
183
184 return cpufreq_frequency_table_cpuinfo(policy, table);
185}
186
187static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
188{
189 if (cpufreq_us3_driver)
190 us3_set_cpu_divider_index(policy, 0);
191
192 return 0;
193}
194
195static int __init us3_freq_init(void)
196{
197 unsigned long manuf, impl, ver;
198 int ret;
199
200 if (tlb_type != cheetah && tlb_type != cheetah_plus)
201 return -ENODEV;
202
203 __asm__("rdpr %%ver, %0" : "=r" (ver));
204 manuf = ((ver >> 48) & 0xffff);
205 impl = ((ver >> 32) & 0xffff);
206
207 if (manuf == CHEETAH_MANUF &&
208 (impl == CHEETAH_IMPL ||
209 impl == CHEETAH_PLUS_IMPL ||
210 impl == JAGUAR_IMPL ||
211 impl == PANTHER_IMPL)) {
212 struct cpufreq_driver *driver;
213
214 ret = -ENOMEM;
215 driver = kzalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
216 if (!driver)
217 goto err_out;
218
219 us3_freq_table = kzalloc(
220 (NR_CPUS * sizeof(struct us3_freq_percpu_info)),
221 GFP_KERNEL);
222 if (!us3_freq_table)
223 goto err_out;
224
225 driver->init = us3_freq_cpu_init;
226 driver->verify = us3_freq_verify;
227 driver->target = us3_freq_target;
228 driver->get = us3_freq_get;
229 driver->exit = us3_freq_cpu_exit;
230 driver->owner = THIS_MODULE,
231 strcpy(driver->name, "UltraSPARC-III");
232
233 cpufreq_us3_driver = driver;
234 ret = cpufreq_register_driver(driver);
235 if (ret)
236 goto err_out;
237
238 return 0;
239
240err_out:
241 if (driver) {
242 kfree(driver);
243 cpufreq_us3_driver = NULL;
244 }
245 kfree(us3_freq_table);
246 us3_freq_table = NULL;
247 return ret;
248 }
249
250 return -ENODEV;
251}
252
253static void __exit us3_freq_exit(void)
254{
255 if (cpufreq_us3_driver) {
256 cpufreq_unregister_driver(cpufreq_us3_driver);
257 kfree(cpufreq_us3_driver);
258 cpufreq_us3_driver = NULL;
259 kfree(us3_freq_table);
260 us3_freq_table = NULL;
261 }
262}
263
264MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
265MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
266MODULE_LICENSE("GPL");
267
268module_init(us3_freq_init);
269module_exit(us3_freq_exit);
270
