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1// SPDX-License-Identifier: GPL-2.0-only
2/* us3_cpufreq.c: UltraSPARC-III cpu frequency support
3 *
4 * Copyright (C) 2003 David S. Miller (davem@redhat.com)
5 *
6 * Many thanks to Dominik Brodowski for fixing up the cpufreq
7 * infrastructure in order to make this driver easier to implement.
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/sched.h>
13#include <linux/smp.h>
14#include <linux/cpufreq.h>
15#include <linux/threads.h>
16#include <linux/slab.h>
17#include <linux/init.h>
18
19#include <asm/head.h>
20#include <asm/timer.h>
21
22struct us3_freq_percpu_info {
23 struct cpufreq_frequency_table table[4];
24};
25
26/* Indexed by cpu number. */
27static struct us3_freq_percpu_info *us3_freq_table;
28
29/* UltraSPARC-III has three dividers: 1, 2, and 32. These are controlled
30 * in the Safari config register.
31 */
32#define SAFARI_CFG_DIV_1 0x0000000000000000UL
33#define SAFARI_CFG_DIV_2 0x0000000040000000UL
34#define SAFARI_CFG_DIV_32 0x0000000080000000UL
35#define SAFARI_CFG_DIV_MASK 0x00000000C0000000UL
36
37static void read_safari_cfg(void *arg)
38{
39 unsigned long ret, *val = arg;
40
41 __asm__ __volatile__("ldxa [%%g0] %1, %0"
42 : "=&r" (ret)
43 : "i" (ASI_SAFARI_CONFIG));
44 *val = ret;
45}
46
47static void update_safari_cfg(void *arg)
48{
49 unsigned long reg, *new_bits = arg;
50
51 read_safari_cfg(®);
52 reg &= ~SAFARI_CFG_DIV_MASK;
53 reg |= *new_bits;
54
55 __asm__ __volatile__("stxa %0, [%%g0] %1\n\t"
56 "membar #Sync"
57 : /* no outputs */
58 : "r" (reg), "i" (ASI_SAFARI_CONFIG)
59 : "memory");
60}
61
62static unsigned long get_current_freq(unsigned int cpu, unsigned long safari_cfg)
63{
64 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
65 unsigned long ret;
66
67 switch (safari_cfg & SAFARI_CFG_DIV_MASK) {
68 case SAFARI_CFG_DIV_1:
69 ret = clock_tick / 1;
70 break;
71 case SAFARI_CFG_DIV_2:
72 ret = clock_tick / 2;
73 break;
74 case SAFARI_CFG_DIV_32:
75 ret = clock_tick / 32;
76 break;
77 default:
78 BUG();
79 }
80
81 return ret;
82}
83
84static unsigned int us3_freq_get(unsigned int cpu)
85{
86 unsigned long reg;
87
88 if (smp_call_function_single(cpu, read_safari_cfg, ®, 1))
89 return 0;
90 return get_current_freq(cpu, reg);
91}
92
93static int us3_freq_target(struct cpufreq_policy *policy, unsigned int index)
94{
95 unsigned int cpu = policy->cpu;
96 unsigned long new_bits, new_freq;
97
98 new_freq = sparc64_get_clock_tick(cpu) / 1000;
99 switch (index) {
100 case 0:
101 new_bits = SAFARI_CFG_DIV_1;
102 new_freq /= 1;
103 break;
104 case 1:
105 new_bits = SAFARI_CFG_DIV_2;
106 new_freq /= 2;
107 break;
108 case 2:
109 new_bits = SAFARI_CFG_DIV_32;
110 new_freq /= 32;
111 break;
112
113 default:
114 BUG();
115 }
116
117 return smp_call_function_single(cpu, update_safari_cfg, &new_bits, 1);
118}
119
120static int us3_freq_cpu_init(struct cpufreq_policy *policy)
121{
122 unsigned int cpu = policy->cpu;
123 unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
124 struct cpufreq_frequency_table *table =
125 &us3_freq_table[cpu].table[0];
126
127 table[0].driver_data = 0;
128 table[0].frequency = clock_tick / 1;
129 table[1].driver_data = 1;
130 table[1].frequency = clock_tick / 2;
131 table[2].driver_data = 2;
132 table[2].frequency = clock_tick / 32;
133 table[3].driver_data = 0;
134 table[3].frequency = CPUFREQ_TABLE_END;
135
136 policy->cpuinfo.transition_latency = 0;
137 policy->cur = clock_tick;
138 policy->freq_table = table;
139
140 return 0;
141}
142
143static int us3_freq_cpu_exit(struct cpufreq_policy *policy)
144{
145 us3_freq_target(policy, 0);
146 return 0;
147}
148
149static struct cpufreq_driver cpufreq_us3_driver = {
150 .name = "UltraSPARC-III",
151 .init = us3_freq_cpu_init,
152 .verify = cpufreq_generic_frequency_table_verify,
153 .target_index = us3_freq_target,
154 .get = us3_freq_get,
155 .exit = us3_freq_cpu_exit,
156};
157
158static int __init us3_freq_init(void)
159{
160 unsigned long manuf, impl, ver;
161 int ret;
162
163 if (tlb_type != cheetah && tlb_type != cheetah_plus)
164 return -ENODEV;
165
166 __asm__("rdpr %%ver, %0" : "=r" (ver));
167 manuf = ((ver >> 48) & 0xffff);
168 impl = ((ver >> 32) & 0xffff);
169
170 if (manuf == CHEETAH_MANUF &&
171 (impl == CHEETAH_IMPL ||
172 impl == CHEETAH_PLUS_IMPL ||
173 impl == JAGUAR_IMPL ||
174 impl == PANTHER_IMPL)) {
175 us3_freq_table = kzalloc(NR_CPUS * sizeof(*us3_freq_table),
176 GFP_KERNEL);
177 if (!us3_freq_table)
178 return -ENOMEM;
179
180 ret = cpufreq_register_driver(&cpufreq_us3_driver);
181 if (ret)
182 kfree(us3_freq_table);
183
184 return ret;
185 }
186
187 return -ENODEV;
188}
189
190static void __exit us3_freq_exit(void)
191{
192 cpufreq_unregister_driver(&cpufreq_us3_driver);
193 kfree(us3_freq_table);
194}
195
196MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
197MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-III");
198MODULE_LICENSE("GPL");
199
200module_init(us3_freq_init);
201module_exit(us3_freq_exit);
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
21static struct cpufreq_driver *cpufreq_us3_driver;
22
23struct us3_freq_percpu_info {
24 struct cpufreq_frequency_table table[4];
25};
26
27/* Indexed by cpu number. */
28static 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
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 : /* no outputs */
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);