1 /*- 2 * Copyright (c) 2003-2005 Nate Lawson (SDG) 3 * Copyright (c) 2001 Michael Smith 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "opt_acpi.h" 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/cpu.h> 35 #include <sys/kernel.h> 36 #include <sys/malloc.h> 37 #include <sys/module.h> 38 #include <sys/rman.h> 39 40 #include <machine/bus.h> 41 42 #include <contrib/dev/acpica/include/acpi.h> 43 44 #include <dev/acpica/acpivar.h> 45 #include <dev/pci/pcivar.h> 46 47 #include "cpufreq_if.h" 48 49 /* 50 * Throttling provides relative frequency control. It involves modulating 51 * the clock so that the CPU is active for only a fraction of the normal 52 * clock cycle. It does not change voltage and so is less efficient than 53 * other mechanisms. Since it is relative, it can be used in addition to 54 * absolute cpufreq drivers. We support the ACPI 2.0 specification. 55 */ 56 57 struct acpi_throttle_softc { 58 device_t cpu_dev; 59 ACPI_HANDLE cpu_handle; 60 uint32_t cpu_p_blk; /* ACPI P_BLK location */ 61 uint32_t cpu_p_blk_len; /* P_BLK length (must be 6). */ 62 struct resource *cpu_p_cnt; /* Throttling control register */ 63 int cpu_p_type; /* Resource type for cpu_p_cnt. */ 64 uint32_t cpu_thr_state; /* Current throttle setting. */ 65 }; 66 67 #define THR_GET_REG(reg) \ 68 (bus_space_read_4(rman_get_bustag((reg)), \ 69 rman_get_bushandle((reg)), 0)) 70 #define THR_SET_REG(reg, val) \ 71 (bus_space_write_4(rman_get_bustag((reg)), \ 72 rman_get_bushandle((reg)), 0, (val))) 73 74 /* 75 * Speeds are stored in counts, from 1 to CPU_MAX_SPEED, and 76 * reported to the user in hundredths of a percent. 77 */ 78 #define CPU_MAX_SPEED (1 << cpu_duty_width) 79 #define CPU_SPEED_PERCENT(x) ((10000 * (x)) / CPU_MAX_SPEED) 80 #define CPU_SPEED_PRINTABLE(x) (CPU_SPEED_PERCENT(x) / 10), \ 81 (CPU_SPEED_PERCENT(x) % 10) 82 #define CPU_P_CNT_THT_EN (1<<4) 83 #define CPU_QUIRK_NO_THROTTLE (1<<1) /* Throttling is not usable. */ 84 85 #define PCI_VENDOR_INTEL 0x8086 86 #define PCI_DEVICE_82371AB_3 0x7113 /* PIIX4 chipset for quirks. */ 87 #define PCI_REVISION_A_STEP 0 88 #define PCI_REVISION_B_STEP 1 89 90 static uint32_t cpu_duty_offset; /* Offset in P_CNT of throttle val. */ 91 static uint32_t cpu_duty_width; /* Bit width of throttle value. */ 92 static int thr_rid; /* Driver-wide resource id. */ 93 static int thr_quirks; /* Indicate any hardware bugs. */ 94 95 static void acpi_throttle_identify(driver_t *driver, device_t parent); 96 static int acpi_throttle_probe(device_t dev); 97 static int acpi_throttle_attach(device_t dev); 98 static int acpi_throttle_evaluate(struct acpi_throttle_softc *sc); 99 static void acpi_throttle_quirks(struct acpi_throttle_softc *sc); 100 static int acpi_thr_settings(device_t dev, struct cf_setting *sets, 101 int *count); 102 static int acpi_thr_set(device_t dev, const struct cf_setting *set); 103 static int acpi_thr_get(device_t dev, struct cf_setting *set); 104 static int acpi_thr_type(device_t dev, int *type); 105 106 static device_method_t acpi_throttle_methods[] = { 107 /* Device interface */ 108 DEVMETHOD(device_identify, acpi_throttle_identify), 109 DEVMETHOD(device_probe, acpi_throttle_probe), 110 DEVMETHOD(device_attach, acpi_throttle_attach), 111 112 /* cpufreq interface */ 113 DEVMETHOD(cpufreq_drv_set, acpi_thr_set), 114 DEVMETHOD(cpufreq_drv_get, acpi_thr_get), 115 DEVMETHOD(cpufreq_drv_type, acpi_thr_type), 116 DEVMETHOD(cpufreq_drv_settings, acpi_thr_settings), 117 DEVMETHOD_END 118 }; 119 120 static driver_t acpi_throttle_driver = { 121 "acpi_throttle", 122 acpi_throttle_methods, 123 sizeof(struct acpi_throttle_softc), 124 }; 125 126 DRIVER_MODULE(acpi_throttle, cpu, acpi_throttle_driver, 0, 0); 127 128 static void 129 acpi_throttle_identify(driver_t *driver, device_t parent) 130 { 131 ACPI_BUFFER buf; 132 ACPI_HANDLE handle; 133 ACPI_OBJECT *obj; 134 135 /* Make sure we're not being doubly invoked. */ 136 if (device_find_child(parent, "acpi_throttle", -1)) 137 return; 138 139 /* Check for a valid duty width and parent CPU type. */ 140 handle = acpi_get_handle(parent); 141 if (handle == NULL) 142 return; 143 if (AcpiGbl_FADT.DutyWidth == 0 || 144 acpi_get_type(parent) != ACPI_TYPE_PROCESSOR) 145 return; 146 147 /* 148 * Add a child if there's a non-NULL P_BLK and correct length, or 149 * if the _PTC method is present. 150 */ 151 buf.Pointer = NULL; 152 buf.Length = ACPI_ALLOCATE_BUFFER; 153 if (ACPI_FAILURE(AcpiEvaluateObject(handle, NULL, NULL, &buf))) 154 return; 155 obj = (ACPI_OBJECT *)buf.Pointer; 156 if ((obj->Processor.PblkAddress && obj->Processor.PblkLength >= 4) || 157 ACPI_SUCCESS(AcpiEvaluateObject(handle, "_PTC", NULL, NULL))) { 158 if (BUS_ADD_CHILD(parent, 0, "acpi_throttle", 159 device_get_unit(parent)) == NULL) 160 device_printf(parent, "add throttle child failed\n"); 161 } 162 AcpiOsFree(obj); 163 } 164 165 static int 166 acpi_throttle_probe(device_t dev) 167 { 168 169 if (resource_disabled("acpi_throttle", 0)) 170 return (ENXIO); 171 172 /* 173 * On i386 platforms at least, ACPI throttling is accomplished by 174 * the chipset modulating the STPCLK# pin based on the duty cycle. 175 * Since p4tcc uses the same mechanism (but internal to the CPU), 176 * we disable acpi_throttle when p4tcc is also present. 177 */ 178 if (device_find_child(device_get_parent(dev), "p4tcc", -1) && 179 !resource_disabled("p4tcc", 0)) 180 return (ENXIO); 181 182 device_set_desc(dev, "ACPI CPU Throttling"); 183 return (0); 184 } 185 186 static int 187 acpi_throttle_attach(device_t dev) 188 { 189 struct acpi_throttle_softc *sc; 190 struct cf_setting set; 191 ACPI_BUFFER buf; 192 ACPI_OBJECT *obj; 193 ACPI_STATUS status; 194 int error; 195 196 sc = device_get_softc(dev); 197 sc->cpu_dev = dev; 198 sc->cpu_handle = acpi_get_handle(dev); 199 200 buf.Pointer = NULL; 201 buf.Length = ACPI_ALLOCATE_BUFFER; 202 status = AcpiEvaluateObject(sc->cpu_handle, NULL, NULL, &buf); 203 if (ACPI_FAILURE(status)) { 204 device_printf(dev, "attach failed to get Processor obj - %s\n", 205 AcpiFormatException(status)); 206 return (ENXIO); 207 } 208 obj = (ACPI_OBJECT *)buf.Pointer; 209 sc->cpu_p_blk = obj->Processor.PblkAddress; 210 sc->cpu_p_blk_len = obj->Processor.PblkLength; 211 AcpiOsFree(obj); 212 213 /* If this is the first device probed, check for quirks. */ 214 if (device_get_unit(dev) == 0) 215 acpi_throttle_quirks(sc); 216 217 /* Attempt to attach the actual throttling register. */ 218 error = acpi_throttle_evaluate(sc); 219 if (error) 220 return (error); 221 222 /* 223 * Set our initial frequency to the highest since some systems 224 * seem to boot with this at the lowest setting. 225 */ 226 set.freq = 10000; 227 acpi_thr_set(dev, &set); 228 229 /* Everything went ok, register with cpufreq(4). */ 230 cpufreq_register(dev); 231 return (0); 232 } 233 234 static int 235 acpi_throttle_evaluate(struct acpi_throttle_softc *sc) 236 { 237 uint32_t duty_end; 238 ACPI_BUFFER buf; 239 ACPI_OBJECT obj; 240 ACPI_GENERIC_ADDRESS gas; 241 ACPI_STATUS status; 242 243 /* Get throttling parameters from the FADT. 0 means not supported. */ 244 if (device_get_unit(sc->cpu_dev) == 0) { 245 cpu_duty_offset = AcpiGbl_FADT.DutyOffset; 246 cpu_duty_width = AcpiGbl_FADT.DutyWidth; 247 } 248 if (cpu_duty_width == 0 || (thr_quirks & CPU_QUIRK_NO_THROTTLE) != 0) 249 return (ENXIO); 250 251 /* Validate the duty offset/width. */ 252 duty_end = cpu_duty_offset + cpu_duty_width - 1; 253 if (duty_end > 31) { 254 device_printf(sc->cpu_dev, 255 "CLK_VAL field overflows P_CNT register\n"); 256 return (ENXIO); 257 } 258 if (cpu_duty_offset <= 4 && duty_end >= 4) { 259 device_printf(sc->cpu_dev, 260 "CLK_VAL field overlaps THT_EN bit\n"); 261 return (ENXIO); 262 } 263 264 /* 265 * If not present, fall back to using the processor's P_BLK to find 266 * the P_CNT register. 267 * 268 * Note that some systems seem to duplicate the P_BLK pointer 269 * across multiple CPUs, so not getting the resource is not fatal. 270 */ 271 buf.Pointer = &obj; 272 buf.Length = sizeof(obj); 273 status = AcpiEvaluateObject(sc->cpu_handle, "_PTC", NULL, &buf); 274 if (ACPI_SUCCESS(status)) { 275 if (obj.Buffer.Length < sizeof(ACPI_GENERIC_ADDRESS) + 3) { 276 device_printf(sc->cpu_dev, "_PTC buffer too small\n"); 277 return (ENXIO); 278 } 279 memcpy(&gas, obj.Buffer.Pointer + 3, sizeof(gas)); 280 acpi_bus_alloc_gas(sc->cpu_dev, &sc->cpu_p_type, &thr_rid, 281 &gas, &sc->cpu_p_cnt, 0); 282 if (sc->cpu_p_cnt != NULL && bootverbose) { 283 device_printf(sc->cpu_dev, "P_CNT from _PTC %#jx\n", 284 gas.Address); 285 } 286 } 287 288 /* If _PTC not present or other failure, try the P_BLK. */ 289 if (sc->cpu_p_cnt == NULL) { 290 /* 291 * The spec says P_BLK must be 6 bytes long. However, some 292 * systems use it to indicate a fractional set of features 293 * present so we take anything >= 4. 294 */ 295 if (sc->cpu_p_blk_len < 4) 296 return (ENXIO); 297 gas.Address = sc->cpu_p_blk; 298 gas.SpaceId = ACPI_ADR_SPACE_SYSTEM_IO; 299 gas.BitWidth = 32; 300 acpi_bus_alloc_gas(sc->cpu_dev, &sc->cpu_p_type, &thr_rid, 301 &gas, &sc->cpu_p_cnt, 0); 302 if (sc->cpu_p_cnt != NULL) { 303 if (bootverbose) 304 device_printf(sc->cpu_dev, 305 "P_CNT from P_BLK %#x\n", sc->cpu_p_blk); 306 } else { 307 device_printf(sc->cpu_dev, "failed to attach P_CNT\n"); 308 return (ENXIO); 309 } 310 } 311 thr_rid++; 312 313 return (0); 314 } 315 316 static void 317 acpi_throttle_quirks(struct acpi_throttle_softc *sc) 318 { 319 #ifdef __i386__ 320 device_t acpi_dev; 321 322 /* Look for various quirks of the PIIX4 part. */ 323 acpi_dev = pci_find_device(PCI_VENDOR_INTEL, PCI_DEVICE_82371AB_3); 324 if (acpi_dev) { 325 switch (pci_get_revid(acpi_dev)) { 326 /* 327 * Disable throttling control on PIIX4 A and B-step. 328 * See specification changes #13 ("Manual Throttle Duty Cycle") 329 * and #14 ("Enabling and Disabling Manual Throttle"), plus 330 * erratum #5 ("STPCLK# Deassertion Time") from the January 331 * 2002 PIIX4 specification update. Note that few (if any) 332 * mobile systems ever used this part. 333 */ 334 case PCI_REVISION_A_STEP: 335 case PCI_REVISION_B_STEP: 336 thr_quirks |= CPU_QUIRK_NO_THROTTLE; 337 break; 338 default: 339 break; 340 } 341 } 342 #endif 343 } 344 345 static int 346 acpi_thr_settings(device_t dev, struct cf_setting *sets, int *count) 347 { 348 int i, speed; 349 350 if (sets == NULL || count == NULL) 351 return (EINVAL); 352 if (*count < CPU_MAX_SPEED) 353 return (E2BIG); 354 355 /* Return a list of valid settings for this driver. */ 356 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * CPU_MAX_SPEED); 357 for (i = 0, speed = CPU_MAX_SPEED; speed != 0; i++, speed--) { 358 sets[i].freq = CPU_SPEED_PERCENT(speed); 359 sets[i].dev = dev; 360 } 361 *count = CPU_MAX_SPEED; 362 363 return (0); 364 } 365 366 static int 367 acpi_thr_set(device_t dev, const struct cf_setting *set) 368 { 369 struct acpi_throttle_softc *sc; 370 uint32_t clk_val, p_cnt, speed; 371 372 if (set == NULL) 373 return (EINVAL); 374 sc = device_get_softc(dev); 375 376 /* 377 * Validate requested state converts to a duty cycle that is an 378 * integer from [1 .. CPU_MAX_SPEED]. 379 */ 380 speed = set->freq * CPU_MAX_SPEED / 10000; 381 if (speed * 10000 != set->freq * CPU_MAX_SPEED || 382 speed < 1 || speed > CPU_MAX_SPEED) 383 return (EINVAL); 384 385 /* If we're at this setting, don't bother applying it again. */ 386 if (speed == sc->cpu_thr_state) 387 return (0); 388 389 /* Get the current P_CNT value and disable throttling */ 390 p_cnt = THR_GET_REG(sc->cpu_p_cnt); 391 p_cnt &= ~CPU_P_CNT_THT_EN; 392 THR_SET_REG(sc->cpu_p_cnt, p_cnt); 393 394 /* If we're at maximum speed, that's all */ 395 if (speed < CPU_MAX_SPEED) { 396 /* Mask the old CLK_VAL off and OR in the new value */ 397 clk_val = (CPU_MAX_SPEED - 1) << cpu_duty_offset; 398 p_cnt &= ~clk_val; 399 p_cnt |= (speed << cpu_duty_offset); 400 401 /* Write the new P_CNT value and then enable throttling */ 402 THR_SET_REG(sc->cpu_p_cnt, p_cnt); 403 p_cnt |= CPU_P_CNT_THT_EN; 404 THR_SET_REG(sc->cpu_p_cnt, p_cnt); 405 } 406 sc->cpu_thr_state = speed; 407 408 return (0); 409 } 410 411 static int 412 acpi_thr_get(device_t dev, struct cf_setting *set) 413 { 414 struct acpi_throttle_softc *sc; 415 uint32_t p_cnt, clk_val; 416 417 if (set == NULL) 418 return (EINVAL); 419 sc = device_get_softc(dev); 420 421 /* Get the current throttling setting from P_CNT. */ 422 p_cnt = THR_GET_REG(sc->cpu_p_cnt); 423 clk_val = (p_cnt >> cpu_duty_offset) & (CPU_MAX_SPEED - 1); 424 sc->cpu_thr_state = clk_val; 425 426 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set)); 427 set->freq = CPU_SPEED_PERCENT(clk_val); 428 set->dev = dev; 429 430 return (0); 431 } 432 433 static int 434 acpi_thr_type(device_t dev, int *type) 435 { 436 437 if (type == NULL) 438 return (EINVAL); 439 440 *type = CPUFREQ_TYPE_RELATIVE; 441 return (0); 442 } 443