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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 void read_safari_cfg(void *arg)
39{
40 unsigned long ret, *val = arg;
41
42 __asm__ __volatile__("ldxa [%%g0] %1, %0"
43 : "=&r" (ret)
44 : "i" (ASI_SAFARI_CONFIG));
45 *val = ret;
46}
47
48static void update_safari_cfg(void *arg)
49{
50 unsigned long reg, *new_bits = arg;
51
52 read_safari_cfg(®);
53 reg &= ~SAFARI_CFG_DIV_MASK;
54 reg |= *new_bits;
55
56 __asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
57 "membar #Sync"
58 :
59 : "r" (reg), "i" (ASI_SAFARI_CONFIG)
60 : "memory");
61}
62
63static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
64{
65 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
66 unsigned long ret;
67
68 switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
69 case SAFARI_CFG_DIV_1:
70 ret = clock_tick / 1;
71 break;
72 case SAFARI_CFG_DIV_2:
73 ret = clock_tick / 2;
74 break;
75 case SAFARI_CFG_DIV_32:
76 ret = clock_tick / 32;
77 break;
78 default:
79 BUG();
80 }
81
82 return ret;
83}
84
85static unsigned int us3_freq_get(unsigned int cpu)
86{
87 unsigned long reg;
88
89 if (smp_call_function_single(cpu, read_safari_cfg, ®, 1))
90 return 0;
91 return get_current_freq(cpu, reg);
92}
93
94static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
95{
96 unsigned int cpu = policy->cpu;
97 unsigned long new_bits, new_freq;
98
99 new_freq = sparc64_get_clock_tick(cpu) / 1000;
100 switch (index) {
101 case 0:
102 new_bits = SAFARI_CFG_DIV_1;
103 new_freq /= 1;
104 break;
105 case 1:
106 new_bits = SAFARI_CFG_DIV_2;
107 new_freq /= 2;
108 break;
109 case 2:
110 new_bits = SAFARI_CFG_DIV_32;
111 new_freq /= 32;
112 break;
113
114 default:
115 BUG();
116 }
117
118 return smp_call_function_single(cpu, update_safari_cfg, &new_bits, 1);
119}
120
121static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
122{
123 unsigned int cpu = policy->cpu;
124 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
125 struct cpufreq_frequency_table *table =
126 &us3_freq_table[cpu].table[0];
127
128 table[0].driver_data = 0;
129 table[0].frequency = clock_tick / 1;
130 table[1].driver_data = 1;
131 table[1].frequency = clock_tick / 2;
132 table[2].driver_data = 2;
133 table[2].frequency = clock_tick / 32;
134 table[3].driver_data = 0;
135 table[3].frequency = CPUFREQ_TABLE_END;
136
137 policy->cpuinfo.transition_latency = 0;
138 policy->cur = clock_tick;
139 policy->freq_table = table;
140
141 return 0;
142}
143
144static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
145{
146 if (cpufreq_us3_driver)
147 us3_freq_target(policy, 0);
148
149 return 0;
150}
151
152static int __init us3_freq_init(void)
153{
154 unsigned long manuf, impl, ver;
155 int ret;
156
157 if (tlb_type != cheetah && tlb_type != cheetah_plus)
158 return -ENODEV;
159
160 __asm__("rdpr %%ver, %0" : "=r" (ver));
161 manuf = ((ver >> 48) & 0xffff);
162 impl = ((ver >> 32) & 0xffff);
163
164 if (manuf == CHEETAH_MANUF &&
165 (impl == CHEETAH_IMPL ||
166 impl == CHEETAH_PLUS_IMPL ||
167 impl == JAGUAR_IMPL ||
168 impl == PANTHER_IMPL)) {
169 struct cpufreq_driver *driver;
170
171 ret = -ENOMEM;
172 driver = kzalloc(sizeof(*driver), GFP_KERNEL);
173 if (!driver)
174 goto err_out;
175
176 us3_freq_table = kzalloc((NR_CPUS * sizeof(*us3_freq_table)),
177 GFP_KERNEL);
178 if (!us3_freq_table)
179 goto err_out;
180
181 driver->init = us3_freq_cpu_init;
182 driver->verify = cpufreq_generic_frequency_table_verify;
183 driver->target_index = us3_freq_target;
184 driver->get = us3_freq_get;
185 driver->exit = us3_freq_cpu_exit;
186 strcpy(driver->name, "UltraSPARC-III");
187
188 cpufreq_us3_driver = driver;
189 ret = cpufreq_register_driver(driver);
190 if (ret)
191 goto err_out;
192
193 return 0;
194
195err_out:
196 if (driver) {
197 kfree(driver);
198 cpufreq_us3_driver = NULL;
199 }
200 kfree(us3_freq_table);
201 us3_freq_table = NULL;
202 return ret;
203 }
204
205 return -ENODEV;
206}
207
208static void __exit us3_freq_exit(void)
209{
210 if (cpufreq_us3_driver) {
211 cpufreq_unregister_driver(cpufreq_us3_driver);
212 kfree(cpufreq_us3_driver);
213 cpufreq_us3_driver = NULL;
214 kfree(us3_freq_table);
215 us3_freq_table = NULL;
216 }
217}
218
219MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
220MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
221MODULE_LICENSE("GPL");
222
223module_init(us3_freq_init);
224module_exit(us3_freq_exit);
225
