Loading...
1/*
2 * This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
3 * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
4 * Dominik Brodowski.
5 *
6 * Licensed under the terms of the GNU GPL License version 2.
7 *
8 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/cpufreq.h>
15#include <linux/ioport.h>
16#include <linux/timex.h>
17#include <linux/io.h>
18
19#include <asm/msr.h>
20
21#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long
22 as it is unused */
23
24#define PFX "powernow-k6: "
25static unsigned int busfreq; /* FSB, in 10 kHz */
26static unsigned int max_multiplier;
27
28
29/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
30static struct cpufreq_frequency_table clock_ratio[] = {
31 {45, /* 000 -> 4.5x */ 0},
32 {50, /* 001 -> 5.0x */ 0},
33 {40, /* 010 -> 4.0x */ 0},
34 {55, /* 011 -> 5.5x */ 0},
35 {20, /* 100 -> 2.0x */ 0},
36 {30, /* 101 -> 3.0x */ 0},
37 {60, /* 110 -> 6.0x */ 0},
38 {35, /* 111 -> 3.5x */ 0},
39 {0, CPUFREQ_TABLE_END}
40};
41
42
43/**
44 * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
45 *
46 * Returns the current setting of the frequency multiplier. Core clock
47 * speed is frequency of the Front-Side Bus multiplied with this value.
48 */
49static int powernow_k6_get_cpu_multiplier(void)
50{
51 u64 invalue = 0;
52 u32 msrval;
53
54 msrval = POWERNOW_IOPORT + 0x1;
55 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
56 invalue = inl(POWERNOW_IOPORT + 0x8);
57 msrval = POWERNOW_IOPORT + 0x0;
58 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
59
60 return clock_ratio[(invalue >> 5)&7].index;
61}
62
63
64/**
65 * powernow_k6_set_state - set the PowerNow! multiplier
66 * @best_i: clock_ratio[best_i] is the target multiplier
67 *
68 * Tries to change the PowerNow! multiplier
69 */
70static void powernow_k6_set_state(unsigned int best_i)
71{
72 unsigned long outvalue = 0, invalue = 0;
73 unsigned long msrval;
74 struct cpufreq_freqs freqs;
75
76 if (clock_ratio[best_i].index > max_multiplier) {
77 printk(KERN_ERR PFX "invalid target frequency\n");
78 return;
79 }
80
81 freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
82 freqs.new = busfreq * clock_ratio[best_i].index;
83 freqs.cpu = 0; /* powernow-k6.c is UP only driver */
84
85 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
86
87 /* we now need to transform best_i to the BVC format, see AMD#23446 */
88
89 outvalue = (1<<12) | (1<<10) | (1<<9) | (best_i<<5);
90
91 msrval = POWERNOW_IOPORT + 0x1;
92 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
93 invalue = inl(POWERNOW_IOPORT + 0x8);
94 invalue = invalue & 0xf;
95 outvalue = outvalue | invalue;
96 outl(outvalue , (POWERNOW_IOPORT + 0x8));
97 msrval = POWERNOW_IOPORT + 0x0;
98 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
99
100 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
101
102 return;
103}
104
105
106/**
107 * powernow_k6_verify - verifies a new CPUfreq policy
108 * @policy: new policy
109 *
110 * Policy must be within lowest and highest possible CPU Frequency,
111 * and at least one possible state must be within min and max.
112 */
113static int powernow_k6_verify(struct cpufreq_policy *policy)
114{
115 return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
116}
117
118
119/**
120 * powernow_k6_setpolicy - sets a new CPUFreq policy
121 * @policy: new policy
122 * @target_freq: the target frequency
123 * @relation: how that frequency relates to achieved frequency
124 * (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
125 *
126 * sets a new CPUFreq policy
127 */
128static int powernow_k6_target(struct cpufreq_policy *policy,
129 unsigned int target_freq,
130 unsigned int relation)
131{
132 unsigned int newstate = 0;
133
134 if (cpufreq_frequency_table_target(policy, &clock_ratio[0],
135 target_freq, relation, &newstate))
136 return -EINVAL;
137
138 powernow_k6_set_state(newstate);
139
140 return 0;
141}
142
143
144static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
145{
146 unsigned int i, f;
147 int result;
148
149 if (policy->cpu != 0)
150 return -ENODEV;
151
152 /* get frequencies */
153 max_multiplier = powernow_k6_get_cpu_multiplier();
154 busfreq = cpu_khz / max_multiplier;
155
156 /* table init */
157 for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
158 f = clock_ratio[i].index;
159 if (f > max_multiplier)
160 clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
161 else
162 clock_ratio[i].frequency = busfreq * f;
163 }
164
165 /* cpuinfo and default policy values */
166 policy->cpuinfo.transition_latency = 200000;
167 policy->cur = busfreq * max_multiplier;
168
169 result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);
170 if (result)
171 return result;
172
173 cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu);
174
175 return 0;
176}
177
178
179static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
180{
181 unsigned int i;
182 for (i = 0; i < 8; i++) {
183 if (i == max_multiplier)
184 powernow_k6_set_state(i);
185 }
186 cpufreq_frequency_table_put_attr(policy->cpu);
187 return 0;
188}
189
190static unsigned int powernow_k6_get(unsigned int cpu)
191{
192 unsigned int ret;
193 ret = (busfreq * powernow_k6_get_cpu_multiplier());
194 return ret;
195}
196
197static struct freq_attr *powernow_k6_attr[] = {
198 &cpufreq_freq_attr_scaling_available_freqs,
199 NULL,
200};
201
202static struct cpufreq_driver powernow_k6_driver = {
203 .verify = powernow_k6_verify,
204 .target = powernow_k6_target,
205 .init = powernow_k6_cpu_init,
206 .exit = powernow_k6_cpu_exit,
207 .get = powernow_k6_get,
208 .name = "powernow-k6",
209 .owner = THIS_MODULE,
210 .attr = powernow_k6_attr,
211};
212
213
214/**
215 * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
216 *
217 * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
218 * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
219 * on success.
220 */
221static int __init powernow_k6_init(void)
222{
223 struct cpuinfo_x86 *c = &cpu_data(0);
224
225 if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 5) ||
226 ((c->x86_model != 12) && (c->x86_model != 13)))
227 return -ENODEV;
228
229 if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
230 printk(KERN_INFO PFX "PowerNow IOPORT region already used.\n");
231 return -EIO;
232 }
233
234 if (cpufreq_register_driver(&powernow_k6_driver)) {
235 release_region(POWERNOW_IOPORT, 16);
236 return -EINVAL;
237 }
238
239 return 0;
240}
241
242
243/**
244 * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
245 *
246 * Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
247 */
248static void __exit powernow_k6_exit(void)
249{
250 cpufreq_unregister_driver(&powernow_k6_driver);
251 release_region(POWERNOW_IOPORT, 16);
252}
253
254
255MODULE_AUTHOR("Arjan van de Ven, Dave Jones <davej@redhat.com>, "
256 "Dominik Brodowski <linux@brodo.de>");
257MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
258MODULE_LICENSE("GPL");
259
260module_init(powernow_k6_init);
261module_exit(powernow_k6_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
4 * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä,
5 * Dominik Brodowski.
6 *
7 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/cpufreq.h>
16#include <linux/ioport.h>
17#include <linux/timex.h>
18#include <linux/io.h>
19
20#include <asm/cpu_device_id.h>
21#include <asm/msr.h>
22
23#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long
24 as it is unused */
25
26static unsigned int busfreq; /* FSB, in 10 kHz */
27static unsigned int max_multiplier;
28
29static unsigned int param_busfreq = 0;
30static unsigned int param_max_multiplier = 0;
31
32module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO);
33MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)");
34
35module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO);
36MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz");
37
38/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
39static struct cpufreq_frequency_table clock_ratio[] = {
40 {0, 60, /* 110 -> 6.0x */ 0},
41 {0, 55, /* 011 -> 5.5x */ 0},
42 {0, 50, /* 001 -> 5.0x */ 0},
43 {0, 45, /* 000 -> 4.5x */ 0},
44 {0, 40, /* 010 -> 4.0x */ 0},
45 {0, 35, /* 111 -> 3.5x */ 0},
46 {0, 30, /* 101 -> 3.0x */ 0},
47 {0, 20, /* 100 -> 2.0x */ 0},
48 {0, 0, CPUFREQ_TABLE_END}
49};
50
51static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 };
52static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 };
53
54static const struct {
55 unsigned freq;
56 unsigned mult;
57} usual_frequency_table[] = {
58 { 350000, 35 }, // 100 * 3.5
59 { 400000, 40 }, // 100 * 4
60 { 450000, 45 }, // 100 * 4.5
61 { 475000, 50 }, // 95 * 5
62 { 500000, 50 }, // 100 * 5
63 { 506250, 45 }, // 112.5 * 4.5
64 { 533500, 55 }, // 97 * 5.5
65 { 550000, 55 }, // 100 * 5.5
66 { 562500, 50 }, // 112.5 * 5
67 { 570000, 60 }, // 95 * 6
68 { 600000, 60 }, // 100 * 6
69 { 618750, 55 }, // 112.5 * 5.5
70 { 660000, 55 }, // 120 * 5.5
71 { 675000, 60 }, // 112.5 * 6
72 { 720000, 60 }, // 120 * 6
73};
74
75#define FREQ_RANGE 3000
76
77/**
78 * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
79 *
80 * Returns the current setting of the frequency multiplier. Core clock
81 * speed is frequency of the Front-Side Bus multiplied with this value.
82 */
83static int powernow_k6_get_cpu_multiplier(void)
84{
85 unsigned long invalue = 0;
86 u32 msrval;
87
88 local_irq_disable();
89
90 msrval = POWERNOW_IOPORT + 0x1;
91 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
92 invalue = inl(POWERNOW_IOPORT + 0x8);
93 msrval = POWERNOW_IOPORT + 0x0;
94 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
95
96 local_irq_enable();
97
98 return clock_ratio[register_to_index[(invalue >> 5)&7]].driver_data;
99}
100
101static void powernow_k6_set_cpu_multiplier(unsigned int best_i)
102{
103 unsigned long outvalue, invalue;
104 unsigned long msrval;
105 unsigned long cr0;
106
107 /* we now need to transform best_i to the BVC format, see AMD#23446 */
108
109 /*
110 * The processor doesn't respond to inquiry cycles while changing the
111 * frequency, so we must disable cache.
112 */
113 local_irq_disable();
114 cr0 = read_cr0();
115 write_cr0(cr0 | X86_CR0_CD);
116 wbinvd();
117
118 outvalue = (1<<12) | (1<<10) | (1<<9) | (index_to_register[best_i]<<5);
119
120 msrval = POWERNOW_IOPORT + 0x1;
121 wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
122 invalue = inl(POWERNOW_IOPORT + 0x8);
123 invalue = invalue & 0x1f;
124 outvalue = outvalue | invalue;
125 outl(outvalue, (POWERNOW_IOPORT + 0x8));
126 msrval = POWERNOW_IOPORT + 0x0;
127 wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
128
129 write_cr0(cr0);
130 local_irq_enable();
131}
132
133/**
134 * powernow_k6_target - set the PowerNow! multiplier
135 * @best_i: clock_ratio[best_i] is the target multiplier
136 *
137 * Tries to change the PowerNow! multiplier
138 */
139static int powernow_k6_target(struct cpufreq_policy *policy,
140 unsigned int best_i)
141{
142
143 if (clock_ratio[best_i].driver_data > max_multiplier) {
144 pr_err("invalid target frequency\n");
145 return -EINVAL;
146 }
147
148 powernow_k6_set_cpu_multiplier(best_i);
149
150 return 0;
151}
152
153static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
154{
155 struct cpufreq_frequency_table *pos;
156 unsigned int i, f;
157 unsigned khz;
158
159 if (policy->cpu != 0)
160 return -ENODEV;
161
162 max_multiplier = 0;
163 khz = cpu_khz;
164 for (i = 0; i < ARRAY_SIZE(usual_frequency_table); i++) {
165 if (khz >= usual_frequency_table[i].freq - FREQ_RANGE &&
166 khz <= usual_frequency_table[i].freq + FREQ_RANGE) {
167 khz = usual_frequency_table[i].freq;
168 max_multiplier = usual_frequency_table[i].mult;
169 break;
170 }
171 }
172 if (param_max_multiplier) {
173 cpufreq_for_each_entry(pos, clock_ratio)
174 if (pos->driver_data == param_max_multiplier) {
175 max_multiplier = param_max_multiplier;
176 goto have_max_multiplier;
177 }
178 pr_err("invalid max_multiplier parameter, valid parameters 20, 30, 35, 40, 45, 50, 55, 60\n");
179 return -EINVAL;
180 }
181
182 if (!max_multiplier) {
183 pr_warn("unknown frequency %u, cannot determine current multiplier\n",
184 khz);
185 pr_warn("use module parameters max_multiplier and bus_frequency\n");
186 return -EOPNOTSUPP;
187 }
188
189have_max_multiplier:
190 param_max_multiplier = max_multiplier;
191
192 if (param_busfreq) {
193 if (param_busfreq >= 50000 && param_busfreq <= 150000) {
194 busfreq = param_busfreq / 10;
195 goto have_busfreq;
196 }
197 pr_err("invalid bus_frequency parameter, allowed range 50000 - 150000 kHz\n");
198 return -EINVAL;
199 }
200
201 busfreq = khz / max_multiplier;
202have_busfreq:
203 param_busfreq = busfreq * 10;
204
205 /* table init */
206 cpufreq_for_each_entry(pos, clock_ratio) {
207 f = pos->driver_data;
208 if (f > max_multiplier)
209 pos->frequency = CPUFREQ_ENTRY_INVALID;
210 else
211 pos->frequency = busfreq * f;
212 }
213
214 /* cpuinfo and default policy values */
215 policy->cpuinfo.transition_latency = 500000;
216 policy->freq_table = clock_ratio;
217
218 return 0;
219}
220
221
222static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
223{
224 unsigned int i;
225
226 for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
227 if (clock_ratio[i].driver_data == max_multiplier) {
228 struct cpufreq_freqs freqs;
229
230 freqs.old = policy->cur;
231 freqs.new = clock_ratio[i].frequency;
232 freqs.flags = 0;
233
234 cpufreq_freq_transition_begin(policy, &freqs);
235 powernow_k6_target(policy, i);
236 cpufreq_freq_transition_end(policy, &freqs, 0);
237 break;
238 }
239 }
240 return 0;
241}
242
243static unsigned int powernow_k6_get(unsigned int cpu)
244{
245 unsigned int ret;
246 ret = (busfreq * powernow_k6_get_cpu_multiplier());
247 return ret;
248}
249
250static struct cpufreq_driver powernow_k6_driver = {
251 .verify = cpufreq_generic_frequency_table_verify,
252 .target_index = powernow_k6_target,
253 .init = powernow_k6_cpu_init,
254 .exit = powernow_k6_cpu_exit,
255 .get = powernow_k6_get,
256 .name = "powernow-k6",
257 .attr = cpufreq_generic_attr,
258};
259
260static const struct x86_cpu_id powernow_k6_ids[] = {
261 X86_MATCH_VENDOR_FAM_MODEL(AMD, 5, 12, NULL),
262 X86_MATCH_VENDOR_FAM_MODEL(AMD, 5, 13, NULL),
263 {}
264};
265MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids);
266
267/**
268 * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
269 *
270 * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
271 * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
272 * on success.
273 */
274static int __init powernow_k6_init(void)
275{
276 if (!x86_match_cpu(powernow_k6_ids))
277 return -ENODEV;
278
279 if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
280 pr_info("PowerNow IOPORT region already used\n");
281 return -EIO;
282 }
283
284 if (cpufreq_register_driver(&powernow_k6_driver)) {
285 release_region(POWERNOW_IOPORT, 16);
286 return -EINVAL;
287 }
288
289 return 0;
290}
291
292
293/**
294 * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
295 *
296 * Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
297 */
298static void __exit powernow_k6_exit(void)
299{
300 cpufreq_unregister_driver(&powernow_k6_driver);
301 release_region(POWERNOW_IOPORT, 16);
302}
303
304
305MODULE_AUTHOR("Arjan van de Ven, Dave Jones, "
306 "Dominik Brodowski <linux@brodo.de>");
307MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
308MODULE_LICENSE("GPL");
309
310module_init(powernow_k6_init);
311module_exit(powernow_k6_exit);