Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 1 | /* |
| 2 | * POWER platform energy management driver |
| 3 | * Copyright (C) 2010 IBM Corporation |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License |
| 7 | * version 2 as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This pseries platform device driver provides access to |
| 10 | * platform energy management capabilities. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/types.h> |
| 15 | #include <linux/errno.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/seq_file.h> |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 18 | #include <linux/device.h> |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 19 | #include <linux/cpu.h> |
| 20 | #include <linux/of.h> |
| 21 | #include <asm/cputhreads.h> |
| 22 | #include <asm/page.h> |
| 23 | #include <asm/hvcall.h> |
Michael Neuling | 0388c79 | 2012-11-06 14:49:16 +0000 | [diff] [blame] | 24 | #include <asm/firmware.h> |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 25 | |
| 26 | |
| 27 | #define MODULE_VERS "1.0" |
| 28 | #define MODULE_NAME "pseries_energy" |
| 29 | |
| 30 | /* Driver flags */ |
| 31 | |
| 32 | static int sysfs_entries; |
| 33 | |
| 34 | /* Helper routines */ |
| 35 | |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 36 | /* Helper Routines to convert between drc_index to cpu numbers */ |
| 37 | |
| 38 | static u32 cpu_to_drc_index(int cpu) |
| 39 | { |
| 40 | struct device_node *dn = NULL; |
| 41 | const int *indexes; |
| 42 | int i; |
| 43 | int rc = 1; |
| 44 | u32 ret = 0; |
| 45 | |
| 46 | dn = of_find_node_by_path("/cpus"); |
| 47 | if (dn == NULL) |
| 48 | goto err; |
| 49 | indexes = of_get_property(dn, "ibm,drc-indexes", NULL); |
| 50 | if (indexes == NULL) |
| 51 | goto err_of_node_put; |
| 52 | /* Convert logical cpu number to core number */ |
| 53 | i = cpu_core_index_of_thread(cpu); |
| 54 | /* |
| 55 | * The first element indexes[0] is the number of drc_indexes |
| 56 | * returned in the list. Hence i+1 will get the drc_index |
| 57 | * corresponding to core number i. |
| 58 | */ |
| 59 | WARN_ON(i > indexes[0]); |
| 60 | ret = indexes[i + 1]; |
| 61 | rc = 0; |
| 62 | |
| 63 | err_of_node_put: |
| 64 | of_node_put(dn); |
| 65 | err: |
| 66 | if (rc) |
| 67 | printk(KERN_WARNING "cpu_to_drc_index(%d) failed", cpu); |
| 68 | return ret; |
| 69 | } |
| 70 | |
| 71 | static int drc_index_to_cpu(u32 drc_index) |
| 72 | { |
| 73 | struct device_node *dn = NULL; |
| 74 | const int *indexes; |
| 75 | int i, cpu = 0; |
| 76 | int rc = 1; |
| 77 | |
| 78 | dn = of_find_node_by_path("/cpus"); |
| 79 | if (dn == NULL) |
| 80 | goto err; |
| 81 | indexes = of_get_property(dn, "ibm,drc-indexes", NULL); |
| 82 | if (indexes == NULL) |
| 83 | goto err_of_node_put; |
| 84 | /* |
| 85 | * First element in the array is the number of drc_indexes |
| 86 | * returned. Search through the list to find the matching |
| 87 | * drc_index and get the core number |
| 88 | */ |
| 89 | for (i = 0; i < indexes[0]; i++) { |
| 90 | if (indexes[i + 1] == drc_index) |
| 91 | break; |
| 92 | } |
| 93 | /* Convert core number to logical cpu number */ |
| 94 | cpu = cpu_first_thread_of_core(i); |
| 95 | rc = 0; |
| 96 | |
| 97 | err_of_node_put: |
| 98 | of_node_put(dn); |
| 99 | err: |
| 100 | if (rc) |
| 101 | printk(KERN_WARNING "drc_index_to_cpu(%d) failed", drc_index); |
| 102 | return cpu; |
| 103 | } |
| 104 | |
| 105 | /* |
| 106 | * pseries hypervisor call H_BEST_ENERGY provides hints to OS on |
| 107 | * preferred logical cpus to activate or deactivate for optimized |
| 108 | * energy consumption. |
| 109 | */ |
| 110 | |
Anton Blanchard | b0d436c | 2013-08-07 02:01:24 +1000 | [diff] [blame] | 111 | #define FLAGS_MODE1 0x004E200000080E01UL |
| 112 | #define FLAGS_MODE2 0x004E200000080401UL |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 113 | #define FLAGS_ACTIVATE 0x100 |
| 114 | |
| 115 | static ssize_t get_best_energy_list(char *page, int activate) |
| 116 | { |
| 117 | int rc, cnt, i, cpu; |
| 118 | unsigned long retbuf[PLPAR_HCALL9_BUFSIZE]; |
| 119 | unsigned long flags = 0; |
| 120 | u32 *buf_page; |
| 121 | char *s = page; |
| 122 | |
| 123 | buf_page = (u32 *) get_zeroed_page(GFP_KERNEL); |
| 124 | if (!buf_page) |
| 125 | return -ENOMEM; |
| 126 | |
| 127 | flags = FLAGS_MODE1; |
| 128 | if (activate) |
| 129 | flags |= FLAGS_ACTIVATE; |
| 130 | |
| 131 | rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags, 0, __pa(buf_page), |
| 132 | 0, 0, 0, 0, 0, 0); |
| 133 | if (rc != H_SUCCESS) { |
| 134 | free_page((unsigned long) buf_page); |
| 135 | return -EINVAL; |
| 136 | } |
| 137 | |
| 138 | cnt = retbuf[0]; |
| 139 | for (i = 0; i < cnt; i++) { |
| 140 | cpu = drc_index_to_cpu(buf_page[2*i+1]); |
| 141 | if ((cpu_online(cpu) && !activate) || |
| 142 | (!cpu_online(cpu) && activate)) |
| 143 | s += sprintf(s, "%d,", cpu); |
| 144 | } |
| 145 | if (s > page) { /* Something to show */ |
| 146 | s--; /* Suppress last comma */ |
| 147 | s += sprintf(s, "\n"); |
| 148 | } |
| 149 | |
| 150 | free_page((unsigned long) buf_page); |
| 151 | return s-page; |
| 152 | } |
| 153 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 154 | static ssize_t get_best_energy_data(struct device *dev, |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 155 | char *page, int activate) |
| 156 | { |
| 157 | int rc; |
| 158 | unsigned long retbuf[PLPAR_HCALL9_BUFSIZE]; |
| 159 | unsigned long flags = 0; |
| 160 | |
| 161 | flags = FLAGS_MODE2; |
| 162 | if (activate) |
| 163 | flags |= FLAGS_ACTIVATE; |
| 164 | |
| 165 | rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags, |
| 166 | cpu_to_drc_index(dev->id), |
| 167 | 0, 0, 0, 0, 0, 0, 0); |
| 168 | |
| 169 | if (rc != H_SUCCESS) |
| 170 | return -EINVAL; |
| 171 | |
| 172 | return sprintf(page, "%lu\n", retbuf[1] >> 32); |
| 173 | } |
| 174 | |
| 175 | /* Wrapper functions */ |
| 176 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 177 | static ssize_t cpu_activate_hint_list_show(struct device *dev, |
| 178 | struct device_attribute *attr, char *page) |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 179 | { |
| 180 | return get_best_energy_list(page, 1); |
| 181 | } |
| 182 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 183 | static ssize_t cpu_deactivate_hint_list_show(struct device *dev, |
| 184 | struct device_attribute *attr, char *page) |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 185 | { |
| 186 | return get_best_energy_list(page, 0); |
| 187 | } |
| 188 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 189 | static ssize_t percpu_activate_hint_show(struct device *dev, |
| 190 | struct device_attribute *attr, char *page) |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 191 | { |
| 192 | return get_best_energy_data(dev, page, 1); |
| 193 | } |
| 194 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 195 | static ssize_t percpu_deactivate_hint_show(struct device *dev, |
| 196 | struct device_attribute *attr, char *page) |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 197 | { |
| 198 | return get_best_energy_data(dev, page, 0); |
| 199 | } |
| 200 | |
| 201 | /* |
| 202 | * Create sysfs interface: |
| 203 | * /sys/devices/system/cpu/pseries_activate_hint_list |
| 204 | * /sys/devices/system/cpu/pseries_deactivate_hint_list |
| 205 | * Comma separated list of cpus to activate or deactivate |
| 206 | * /sys/devices/system/cpu/cpuN/pseries_activate_hint |
| 207 | * /sys/devices/system/cpu/cpuN/pseries_deactivate_hint |
| 208 | * Per-cpu value of the hint |
| 209 | */ |
| 210 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 211 | struct device_attribute attr_cpu_activate_hint_list = |
| 212 | __ATTR(pseries_activate_hint_list, 0444, |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 213 | cpu_activate_hint_list_show, NULL); |
| 214 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 215 | struct device_attribute attr_cpu_deactivate_hint_list = |
| 216 | __ATTR(pseries_deactivate_hint_list, 0444, |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 217 | cpu_deactivate_hint_list_show, NULL); |
| 218 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 219 | struct device_attribute attr_percpu_activate_hint = |
| 220 | __ATTR(pseries_activate_hint, 0444, |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 221 | percpu_activate_hint_show, NULL); |
| 222 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 223 | struct device_attribute attr_percpu_deactivate_hint = |
| 224 | __ATTR(pseries_deactivate_hint, 0444, |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 225 | percpu_deactivate_hint_show, NULL); |
| 226 | |
| 227 | static int __init pseries_energy_init(void) |
| 228 | { |
| 229 | int cpu, err; |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 230 | struct device *cpu_dev; |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 231 | |
Michael Neuling | 0388c79 | 2012-11-06 14:49:16 +0000 | [diff] [blame] | 232 | if (!firmware_has_feature(FW_FEATURE_BEST_ENERGY)) { |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 233 | printk(KERN_INFO "Hypercall H_BEST_ENERGY not supported\n"); |
| 234 | return 0; |
| 235 | } |
| 236 | /* Create the sysfs files */ |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 237 | err = device_create_file(cpu_subsys.dev_root, |
| 238 | &attr_cpu_activate_hint_list); |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 239 | if (!err) |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 240 | err = device_create_file(cpu_subsys.dev_root, |
| 241 | &attr_cpu_deactivate_hint_list); |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 242 | |
| 243 | if (err) |
| 244 | return err; |
| 245 | for_each_possible_cpu(cpu) { |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 246 | cpu_dev = get_cpu_device(cpu); |
| 247 | err = device_create_file(cpu_dev, |
| 248 | &attr_percpu_activate_hint); |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 249 | if (err) |
| 250 | break; |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 251 | err = device_create_file(cpu_dev, |
| 252 | &attr_percpu_deactivate_hint); |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 253 | if (err) |
| 254 | break; |
| 255 | } |
| 256 | |
| 257 | if (err) |
| 258 | return err; |
| 259 | |
| 260 | sysfs_entries = 1; /* Removed entries on cleanup */ |
| 261 | return 0; |
| 262 | |
| 263 | } |
| 264 | |
| 265 | static void __exit pseries_energy_cleanup(void) |
| 266 | { |
| 267 | int cpu; |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 268 | struct device *cpu_dev; |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 269 | |
| 270 | if (!sysfs_entries) |
| 271 | return; |
| 272 | |
| 273 | /* Remove the sysfs files */ |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 274 | device_remove_file(cpu_subsys.dev_root, &attr_cpu_activate_hint_list); |
| 275 | device_remove_file(cpu_subsys.dev_root, &attr_cpu_deactivate_hint_list); |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 276 | |
| 277 | for_each_possible_cpu(cpu) { |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 278 | cpu_dev = get_cpu_device(cpu); |
| 279 | sysfs_remove_file(&cpu_dev->kobj, |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 280 | &attr_percpu_activate_hint.attr); |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 281 | sysfs_remove_file(&cpu_dev->kobj, |
Vaidyanathan Srinivasan | 5742bd8 | 2010-10-06 08:37:09 +0000 | [diff] [blame] | 282 | &attr_percpu_deactivate_hint.attr); |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | module_init(pseries_energy_init); |
| 287 | module_exit(pseries_energy_cleanup); |
| 288 | MODULE_DESCRIPTION("Driver for pSeries platform energy management"); |
| 289 | MODULE_AUTHOR("Vaidyanathan Srinivasan"); |
| 290 | MODULE_LICENSE("GPL"); |