1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/x86_archext.h> 27 #include <sys/machsystm.h> 28 #include <sys/x_call.h> 29 #include <sys/cpu_acpi.h> 30 #include <sys/cpupm_throttle.h> 31 #include <sys/dtrace.h> 32 #include <sys/sdt.h> 33 34 static int cpupm_throttle_init(cpu_t *); 35 static void cpupm_throttle_fini(cpu_t *); 36 static void cpupm_throttle(cpuset_t, uint32_t); 37 static void cpupm_throttle_stop(cpu_t *); 38 39 cpupm_state_ops_t cpupm_throttle_ops = { 40 "Generic ACPI T-state Support", 41 cpupm_throttle_init, 42 cpupm_throttle_fini, 43 cpupm_throttle, 44 cpupm_throttle_stop 45 }; 46 47 /* 48 * Error returns 49 */ 50 #define THROTTLE_RET_SUCCESS 0x00 51 #define THROTTLE_RET_INCOMPLETE_DATA 0x01 52 #define THROTTLE_RET_UNSUP_STATE 0x02 53 #define THROTTLE_RET_TRANS_INCOMPLETE 0x03 54 55 #define THROTTLE_LATENCY_WAIT 1 56 57 /* 58 * MSR register for clock modulation 59 */ 60 #define IA32_CLOCK_MODULATION_MSR 0x19A 61 62 /* 63 * Debugging support 64 */ 65 #ifdef DEBUG 66 volatile int cpupm_throttle_debug = 0; 67 #define CTDEBUG(arglist) if (cpupm_throttle_debug) printf arglist; 68 #else 69 #define CTDEBUG(arglist) 70 #endif 71 72 /* 73 * Write the _PTC ctrl register. How it is written, depends upon the _PTC 74 * APCI object value. 75 */ 76 static int 77 write_ctrl(cpu_acpi_handle_t handle, uint32_t ctrl) 78 { 79 cpu_acpi_ptc_t *ptc_ctrl; 80 uint64_t reg; 81 int ret = 0; 82 83 ptc_ctrl = CPU_ACPI_PTC_CTRL(handle); 84 85 switch (ptc_ctrl->cr_addrspace_id) { 86 case ACPI_ADR_SPACE_FIXED_HARDWARE: 87 /* 88 * Read current thermal state because reserved bits must be 89 * preserved, compose new value, and write it.The writable 90 * bits are 4:1 (1 to 4). 91 * Bits 3:1 => On-Demand Clock Modulation Duty Cycle 92 * Bit 4 => On-Demand Clock Modulation Enable 93 * Left shift ctrl by 1 to allign with bits 1-4 of MSR 94 */ 95 reg = rdmsr(IA32_CLOCK_MODULATION_MSR); 96 reg &= ~((uint64_t)0x1E); 97 reg |= ctrl; 98 wrmsr(IA32_CLOCK_MODULATION_MSR, reg); 99 break; 100 101 case ACPI_ADR_SPACE_SYSTEM_IO: 102 ret = cpu_acpi_write_port(ptc_ctrl->cr_address, ctrl, 103 ptc_ctrl->cr_width); 104 break; 105 106 default: 107 DTRACE_PROBE1(throttle_ctrl_unsupported_type, uint8_t, 108 ptc_ctrl->cr_addrspace_id); 109 110 ret = -1; 111 } 112 113 DTRACE_PROBE1(throttle_ctrl_write, uint32_t, ctrl); 114 DTRACE_PROBE1(throttle_ctrl_write_err, int, ret); 115 116 return (ret); 117 } 118 119 static int 120 read_status(cpu_acpi_handle_t handle, uint32_t *stat) 121 { 122 cpu_acpi_ptc_t *ptc_stat; 123 uint64_t reg; 124 int ret = 0; 125 126 ptc_stat = CPU_ACPI_PTC_STATUS(handle); 127 128 switch (ptc_stat->cr_addrspace_id) { 129 case ACPI_ADR_SPACE_FIXED_HARDWARE: 130 reg = rdmsr(IA32_CLOCK_MODULATION_MSR); 131 *stat = reg & 0x1E; 132 ret = 0; 133 break; 134 135 case ACPI_ADR_SPACE_SYSTEM_IO: 136 ret = cpu_acpi_read_port(ptc_stat->cr_address, stat, 137 ptc_stat->cr_width); 138 break; 139 140 default: 141 DTRACE_PROBE1(throttle_status_unsupported_type, uint8_t, 142 ptc_stat->cr_addrspace_id); 143 144 return (-1); 145 } 146 147 DTRACE_PROBE1(throttle_status_read, uint32_t, *stat); 148 DTRACE_PROBE1(throttle_status_read_err, int, ret); 149 150 return (ret); 151 } 152 153 /* 154 * Transition the current processor to the requested throttling state. 155 */ 156 static void 157 cpupm_tstate_transition(uint32_t req_state) 158 { 159 cpupm_mach_state_t *mach_state = 160 (cpupm_mach_state_t *)CPU->cpu_m.mcpu_pm_mach_state; 161 cpu_acpi_handle_t handle = mach_state->ms_acpi_handle; 162 cpu_acpi_tstate_t *req_tstate; 163 uint32_t ctrl; 164 uint32_t stat; 165 int i; 166 167 req_tstate = (cpu_acpi_tstate_t *)CPU_ACPI_TSTATES(handle); 168 req_tstate += req_state; 169 DTRACE_PROBE1(throttle_transition, uint32_t, 170 CPU_ACPI_FREQPER(req_tstate)); 171 172 /* 173 * Initiate the processor t-state change. 174 */ 175 ctrl = CPU_ACPI_TSTATE_CTRL(req_tstate); 176 if (write_ctrl(handle, ctrl) != 0) { 177 return; 178 } 179 180 /* 181 * If status is zero, then transition is synchronous and 182 * no status value comparison is required. 183 */ 184 if (CPU_ACPI_TSTATE_STAT(req_tstate) == 0) { 185 return; 186 } 187 188 /* Wait until switch is complete, but bound the loop just in case. */ 189 for (i = CPU_ACPI_TSTATE_TRANSLAT(req_tstate) * 2; i >= 0; 190 i -= THROTTLE_LATENCY_WAIT) { 191 if (read_status(handle, &stat) == 0 && 192 CPU_ACPI_TSTATE_STAT(req_tstate) == stat) 193 break; 194 drv_usecwait(THROTTLE_LATENCY_WAIT); 195 } 196 197 if (CPU_ACPI_TSTATE_STAT(req_tstate) != stat) { 198 DTRACE_PROBE(throttle_transition_incomplete); 199 } 200 } 201 202 static void 203 cpupm_throttle(cpuset_t set, uint32_t throtl_lvl) 204 { 205 /* 206 * If thread is already running on target CPU then just 207 * make the transition request. Otherwise, we'll need to 208 * make a cross-call. 209 */ 210 kpreempt_disable(); 211 if (CPU_IN_SET(set, CPU->cpu_id)) { 212 cpupm_tstate_transition(throtl_lvl); 213 CPUSET_DEL(set, CPU->cpu_id); 214 } 215 if (!CPUSET_ISNULL(set)) { 216 xc_call((xc_arg_t)throtl_lvl, 0, 0, 217 CPUSET2BV(set), (xc_func_t)cpupm_tstate_transition); 218 } 219 kpreempt_enable(); 220 } 221 222 static int 223 cpupm_throttle_init(cpu_t *cp) 224 { 225 cpupm_mach_state_t *mach_state = 226 (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state; 227 cpu_acpi_handle_t handle = mach_state->ms_acpi_handle; 228 cpu_acpi_ptc_t *ptc_stat; 229 int ret; 230 231 if ((ret = cpu_acpi_cache_tstate_data(handle)) != 0) { 232 if (ret < 0) 233 cmn_err(CE_NOTE, 234 "!Support for CPU throttling is being " 235 "disabled due to errors parsing ACPI T-state " 236 "objects exported by BIOS."); 237 cpupm_throttle_fini(cp); 238 return (THROTTLE_RET_INCOMPLETE_DATA); 239 } 240 241 /* 242 * Check the address space used for transitions 243 */ 244 ptc_stat = CPU_ACPI_PTC_STATUS(handle); 245 switch (ptc_stat->cr_addrspace_id) { 246 case ACPI_ADR_SPACE_FIXED_HARDWARE: 247 CTDEBUG(("T-State transitions will use fixed hardware\n")); 248 break; 249 case ACPI_ADR_SPACE_SYSTEM_IO: 250 CTDEBUG(("T-State transitions will use System IO\n")); 251 break; 252 default: 253 cmn_err(CE_NOTE, "!_PTC configured for unsupported " 254 "address space type = %d.", ptc_stat->cr_addrspace_id); 255 return (THROTTLE_RET_INCOMPLETE_DATA); 256 } 257 258 cpupm_alloc_domains(cp, CPUPM_T_STATES); 259 260 return (THROTTLE_RET_SUCCESS); 261 } 262 263 static void 264 cpupm_throttle_fini(cpu_t *cp) 265 { 266 cpupm_mach_state_t *mach_state = 267 (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state; 268 cpu_acpi_handle_t handle = mach_state->ms_acpi_handle; 269 270 cpupm_free_domains(&cpupm_tstate_domains); 271 cpu_acpi_free_tstate_data(handle); 272 } 273 274 static void 275 cpupm_throttle_stop(cpu_t *cp) 276 { 277 cpupm_mach_state_t *mach_state = 278 (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state; 279 cpu_acpi_handle_t handle = mach_state->ms_acpi_handle; 280 281 cpupm_remove_domains(cp, CPUPM_T_STATES, &cpupm_tstate_domains); 282 cpu_acpi_free_tstate_data(handle); 283 } 284 285 /* 286 * This routine reads the ACPI _TPC object. It's accessed as a callback 287 * by the cpu driver whenever a _TPC change notification is received. 288 */ 289 static int 290 cpupm_throttle_get_max(processorid_t cpu_id) 291 { 292 cpu_t *cp = cpu[cpu_id]; 293 cpupm_mach_state_t *mach_state = 294 (cpupm_mach_state_t *)(cp->cpu_m.mcpu_pm_mach_state); 295 cpu_acpi_handle_t handle; 296 int throtl_level; 297 int max_throttle_lvl; 298 uint_t num_throtl; 299 300 if (mach_state == NULL) { 301 return (-1); 302 } 303 304 handle = mach_state->ms_acpi_handle; 305 ASSERT(handle != NULL); 306 307 cpu_acpi_cache_tpc(handle); 308 throtl_level = CPU_ACPI_TPC(handle); 309 310 num_throtl = CPU_ACPI_TSTATES_COUNT(handle); 311 312 max_throttle_lvl = num_throtl - 1; 313 if ((throtl_level < 0) || (throtl_level > max_throttle_lvl)) { 314 cmn_err(CE_NOTE, "!cpupm_throttle_get_max: CPU %d: " 315 "_TPC out of range %d", cp->cpu_id, throtl_level); 316 throtl_level = 0; 317 } 318 319 return (throtl_level); 320 } 321 322 /* 323 * Take care of CPU throttling when _TPC notification arrives 324 */ 325 void 326 cpupm_throttle_manage_notification(void *ctx) 327 { 328 cpu_t *cp = ctx; 329 processorid_t cpu_id = cp->cpu_id; 330 cpupm_mach_state_t *mach_state = 331 (cpupm_mach_state_t *)cp->cpu_m.mcpu_pm_mach_state; 332 boolean_t is_ready; 333 int new_level; 334 335 if (mach_state == NULL) { 336 return; 337 } 338 339 /* 340 * We currently refuse to power-manage if the CPU is not ready to 341 * take cross calls (cross calls fail silently if CPU is not ready 342 * for it). 343 * 344 * Additionally, for x86 platforms we cannot power-manage an instance, 345 * until it has been initialized. 346 */ 347 is_ready = (cp->cpu_flags & CPU_READY) && cpupm_throttle_ready(cp); 348 if (!is_ready) 349 return; 350 351 if (!(mach_state->ms_caps & CPUPM_T_STATES)) 352 return; 353 ASSERT(mach_state->ms_tstate.cma_ops != NULL); 354 355 /* 356 * Get the new T-State support level 357 */ 358 new_level = cpupm_throttle_get_max(cpu_id); 359 360 cpupm_state_change(cp, new_level, CPUPM_T_STATES); 361 } 362