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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 int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
97{
98 unsigned int cpu = policy->cpu;
99 unsigned long new_bits, new_freq, reg;
100 cpumask_t cpus_allowed;
101
102 cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
103 set_cpus_allowed_ptr(current, cpumask_of(cpu));
104
105 new_freq = sparc64_get_clock_tick(cpu) / 1000;
106 switch (index) {
107 case 0:
108 new_bits = SAFARI_CFG_DIV_1;
109 new_freq /= 1;
110 break;
111 case 1:
112 new_bits = SAFARI_CFG_DIV_2;
113 new_freq /= 2;
114 break;
115 case 2:
116 new_bits = SAFARI_CFG_DIV_32;
117 new_freq /= 32;
118 break;
119
120 default:
121 BUG();
122 }
123
124 reg = read_safari_cfg();
125
126 reg &= ~SAFARI_CFG_DIV_MASK;
127 reg |= new_bits;
128 write_safari_cfg(reg);
129
130 set_cpus_allowed_ptr(current, &cpus_allowed);
131
132 return 0;
133}
134
135static int __init us3_freq_cpu_init(struct cpufreq_policy *policy)
136{
137 unsigned int cpu = policy->cpu;
138 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
139 struct cpufreq_frequency_table *table =
140 &us3_freq_table[cpu].table[0];
141
142 table[0].driver_data = 0;
143 table[0].frequency = clock_tick / 1;
144 table[1].driver_data = 1;
145 table[1].frequency = clock_tick / 2;
146 table[2].driver_data = 2;
147 table[2].frequency = clock_tick / 32;
148 table[3].driver_data = 0;
149 table[3].frequency = CPUFREQ_TABLE_END;
150
151 policy->cpuinfo.transition_latency = 0;
152 policy->cur = clock_tick;
153
154 return cpufreq_table_validate_and_show(policy, table);
155}
156
157static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
158{
159 if (cpufreq_us3_driver)
160 us3_freq_target(policy, 0);
161
162 return 0;
163}
164
165static int __init us3_freq_init(void)
166{
167 unsigned long manuf, impl, ver;
168 int ret;
169
170 if (tlb_type != cheetah && tlb_type != cheetah_plus)
171 return -ENODEV;
172
173 __asm__("rdpr %%ver, %0" : "=r" (ver));
174 manuf = ((ver >> 48) & 0xffff);
175 impl = ((ver >> 32) & 0xffff);
176
177 if (manuf == CHEETAH_MANUF &&
178 (impl == CHEETAH_IMPL ||
179 impl == CHEETAH_PLUS_IMPL ||
180 impl == JAGUAR_IMPL ||
181 impl == PANTHER_IMPL)) {
182 struct cpufreq_driver *driver;
183
184 ret = -ENOMEM;
185 driver = kzalloc(sizeof(*driver), GFP_KERNEL);
186 if (!driver)
187 goto err_out;
188
189 us3_freq_table = kzalloc((NR_CPUS * sizeof(*us3_freq_table)),
190 GFP_KERNEL);
191 if (!us3_freq_table)
192 goto err_out;
193
194 driver->init = us3_freq_cpu_init;
195 driver->verify = cpufreq_generic_frequency_table_verify;
196 driver->target_index = us3_freq_target;
197 driver->get = us3_freq_get;
198 driver->exit = us3_freq_cpu_exit;
199 strcpy(driver->name, "UltraSPARC-III");
200
201 cpufreq_us3_driver = driver;
202 ret = cpufreq_register_driver(driver);
203 if (ret)
204 goto err_out;
205
206 return 0;
207
208err_out:
209 if (driver) {
210 kfree(driver);
211 cpufreq_us3_driver = NULL;
212 }
213 kfree(us3_freq_table);
214 us3_freq_table = NULL;
215 return ret;
216 }
217
218 return -ENODEV;
219}
220
221static void __exit us3_freq_exit(void)
222{
223 if (cpufreq_us3_driver) {
224 cpufreq_unregister_driver(cpufreq_us3_driver);
225 kfree(cpufreq_us3_driver);
226 cpufreq_us3_driver = NULL;
227 kfree(us3_freq_table);
228 us3_freq_table = NULL;
229 }
230}
231
232MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
233MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
234MODULE_LICENSE("GPL");
235
236module_init(us3_freq_init);
237module_exit(us3_freq_exit);
238
