2 * Copyright (c) 2001 Michael Smith
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/dev/acpica/acpi_cpu.c,v 1.16.4.1 2003/08/22 20:49:20 jhb Exp $
27 * $DragonFly: src/sys/dev/acpica/Attic/acpi_cpu.c,v 1.1 2003/09/24 03:32:16 drhodus Exp $
31 #include <sys/param.h>
32 #include <sys/kernel.h>
34 #include <sys/power.h>
36 #include <machine/bus_pio.h>
37 #include <machine/bus.h>
38 #include <machine/resource.h>
43 #include <dev/acpica/acpivar.h>
46 * Support for ACPI Processor devices.
48 * Note that this only provides ACPI 1.0 support (with the exception of the
49 * PSTATE_CNT field). 2.0 support will involve implementing _PTC, _PCT,
54 * Hooks for the ACPI CA debugging infrastructure
56 #define _COMPONENT ACPI_PROCESSOR
57 ACPI_MODULE_NAME("PROCESSOR")
59 struct acpi_cpu_softc {
61 ACPI_HANDLE cpu_handle;
65 /* CPU throttling control register */
66 struct resource *cpu_p_blk;
67 #define CPU_GET_P_CNT(sc) (bus_space_read_4(rman_get_bustag((sc)->cpu_p_blk), \
68 rman_get_bushandle((sc)->cpu_p_blk), \
70 #define CPU_SET_P_CNT(sc, val) (bus_space_write_4(rman_get_bustag((sc)->cpu_p_blk), \
71 rman_get_bushandle((sc)->cpu_p_blk), \
73 #define CPU_P_CNT_THT_EN (1<<4)
77 * Speeds are stored in counts, from 1 - CPU_MAX_SPEED, and
78 * reported to the user in tenths of a percent.
80 static u_int32_t cpu_duty_offset;
81 static u_int32_t cpu_duty_width;
82 #define CPU_MAX_SPEED (1 << cpu_duty_width)
83 #define CPU_SPEED_PERCENT(x) ((1000 * (x)) / CPU_MAX_SPEED)
84 #define CPU_SPEED_PRINTABLE(x) (CPU_SPEED_PERCENT(x) / 10),(CPU_SPEED_PERCENT(x) % 10)
86 static u_int32_t cpu_smi_cmd; /* should be a generic way to do this */
87 static u_int8_t cpu_pstate_cnt;
89 static u_int32_t cpu_current_state;
90 static u_int32_t cpu_performance_state;
91 static u_int32_t cpu_economy_state;
92 static u_int32_t cpu_max_state;
94 static device_t *cpu_devices;
95 static int cpu_ndevices;
97 static struct sysctl_ctx_list acpi_cpu_sysctl_ctx;
98 static struct sysctl_oid *acpi_cpu_sysctl_tree;
100 static int acpi_cpu_probe(device_t dev);
101 static int acpi_cpu_attach(device_t dev);
102 static void acpi_cpu_init_throttling(void *arg);
103 static void acpi_cpu_set_speed(u_int32_t speed);
104 static void acpi_cpu_power_profile(void *arg);
105 static int acpi_cpu_speed_sysctl(SYSCTL_HANDLER_ARGS);
107 static device_method_t acpi_cpu_methods[] = {
108 /* Device interface */
109 DEVMETHOD(device_probe, acpi_cpu_probe),
110 DEVMETHOD(device_attach, acpi_cpu_attach),
115 static driver_t acpi_cpu_driver = {
118 sizeof(struct acpi_cpu_softc),
121 static devclass_t acpi_cpu_devclass;
122 DRIVER_MODULE(acpi_cpu, acpi, acpi_cpu_driver, acpi_cpu_devclass, 0, 0);
125 acpi_cpu_probe(device_t dev)
127 if (!acpi_disabled("cpu") &&
128 (acpi_get_type(dev) == ACPI_TYPE_PROCESSOR)) {
129 device_set_desc(dev, "CPU"); /* XXX get more verbose description? */
136 acpi_cpu_attach(device_t dev)
138 struct acpi_cpu_softc *sc;
139 struct acpi_softc *acpi_sc;
140 ACPI_OBJECT processor;
144 u_int32_t p_blk_length;
148 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
152 sc = device_get_softc(dev);
154 sc->cpu_handle = acpi_get_handle(dev);
157 * Get global parameters from the FADT.
159 if (device_get_unit(sc->cpu_dev) == 0) {
160 cpu_duty_offset = AcpiGbl_FADT->DutyOffset;
161 cpu_duty_width = AcpiGbl_FADT->DutyWidth;
162 cpu_smi_cmd = AcpiGbl_FADT->SmiCmd;
163 cpu_pstate_cnt = AcpiGbl_FADT->PstateCnt;
165 /* validate the offset/width */
166 if (cpu_duty_width > 0) {
167 duty_end = cpu_duty_offset + cpu_duty_width - 1;
168 /* check that it fits */
170 printf("acpi_cpu: CLK_VAL field overflows P_CNT register\n");
173 /* check for overlap with the THT_EN bit */
174 if ((cpu_duty_offset <= 4) && (duty_end >= 4)) {
175 printf("acpi_cpu: CLK_VAL field overlaps THT_EN bit\n");
181 * Start the throttling process once the probe phase completes, if we think that
182 * it's going to be useful. If the duty width value is zero, there are no significant
183 * bits in the register and thus no throttled states.
185 if (cpu_duty_width > 0) {
186 AcpiOsQueueForExecution(OSD_PRIORITY_LO, acpi_cpu_init_throttling, NULL);
188 acpi_sc = acpi_device_get_parent_softc(dev);
189 sysctl_ctx_init(&acpi_cpu_sysctl_ctx);
190 acpi_cpu_sysctl_tree = SYSCTL_ADD_NODE(&acpi_cpu_sysctl_ctx,
191 SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree),
192 OID_AUTO, "cpu", CTLFLAG_RD, 0, "");
194 SYSCTL_ADD_INT(&acpi_cpu_sysctl_ctx, SYSCTL_CHILDREN(acpi_cpu_sysctl_tree),
195 OID_AUTO, "max_speed", CTLFLAG_RD,
196 &cpu_max_state, 0, "maximum CPU speed");
197 SYSCTL_ADD_INT(&acpi_cpu_sysctl_ctx, SYSCTL_CHILDREN(acpi_cpu_sysctl_tree),
198 OID_AUTO, "current_speed", CTLFLAG_RD,
199 &cpu_current_state, 0, "current CPU speed");
200 SYSCTL_ADD_PROC(&acpi_cpu_sysctl_ctx, SYSCTL_CHILDREN(acpi_cpu_sysctl_tree),
201 OID_AUTO, "performance_speed", CTLTYPE_INT | CTLFLAG_RW,
202 &cpu_performance_state, 0, acpi_cpu_speed_sysctl, "I", "");
203 SYSCTL_ADD_PROC(&acpi_cpu_sysctl_ctx, SYSCTL_CHILDREN(acpi_cpu_sysctl_tree),
204 OID_AUTO, "economy_speed", CTLTYPE_INT | CTLFLAG_RW,
205 &cpu_economy_state, 0, acpi_cpu_speed_sysctl, "I", "");
210 * Get the processor object.
212 buf.Pointer = &processor;
213 buf.Length = sizeof(processor);
214 if (ACPI_FAILURE(status = AcpiEvaluateObject(sc->cpu_handle, NULL, NULL, &buf))) {
215 device_printf(sc->cpu_dev, "couldn't get Processor object - %s\n", AcpiFormatException(status));
218 if (processor.Type != ACPI_TYPE_PROCESSOR) {
219 device_printf(sc->cpu_dev, "Processor object has bad type %d\n", processor.Type);
222 sc->cpu_id = processor.Processor.ProcId;
225 * If it looks like we support throttling, find this CPU's P_BLK.
227 * Note that some systems seem to duplicate the P_BLK pointer across
228 * multiple CPUs, so not getting the resource is not fatal.
230 * XXX should support _PTC here as well, once we work out how to parse it.
232 * XXX is it valid to assume that the P_BLK must be 6 bytes long?
234 if (cpu_duty_width > 0) {
235 p_blk = processor.Processor.PblkAddress;
236 p_blk_length = processor.Processor.PblkLength;
238 /* allocate bus space if possible */
239 if ((p_blk > 0) && (p_blk_length == 6)) {
241 bus_set_resource(sc->cpu_dev, SYS_RES_IOPORT, rid, p_blk, p_blk_length);
242 sc->cpu_p_blk = bus_alloc_resource(sc->cpu_dev, SYS_RES_IOPORT, &rid, 0, ~0, 1,
245 ACPI_DEBUG_PRINT((ACPI_DB_IO, "acpi_cpu%d: throttling with P_BLK at 0x%x/%d%s\n",
246 device_get_unit(sc->cpu_dev), p_blk, p_blk_length,
247 sc->cpu_p_blk ? "" : " (shadowed)"));
254 * Call this *after* all CPUs have been attached.
256 * Takes the ACPI lock to avoid fighting anyone over the SMI command
257 * port. Could probably lock less code.
260 acpi_cpu_init_throttling(void *arg)
267 /* get set of CPU devices */
268 devclass_get_devices(acpi_cpu_devclass, &cpu_devices, &cpu_ndevices);
270 /* initialise throttling states */
271 cpu_max_state = CPU_MAX_SPEED;
272 cpu_performance_state = cpu_max_state;
273 cpu_economy_state = cpu_performance_state / 2;
274 if (cpu_economy_state == 0) /* 0 is 'reserved' */
276 if (TUNABLE_INT_FETCH("hw.acpi.cpu.performance_speed",
277 &cpu_temp_speed) && cpu_temp_speed > 0 &&
278 cpu_temp_speed <= cpu_max_state)
279 cpu_performance_state = cpu_temp_speed;
280 if (TUNABLE_INT_FETCH("hw.acpi.cpu.economy_speed",
281 &cpu_temp_speed) && cpu_temp_speed > 0 &&
282 cpu_temp_speed <= cpu_max_state)
283 cpu_economy_state = cpu_temp_speed;
285 /* register performance profile change handler */
286 EVENTHANDLER_REGISTER(power_profile_change, acpi_cpu_power_profile, NULL, 0);
288 /* if ACPI 2.0+, signal platform that we are taking over throttling */
289 if (cpu_pstate_cnt != 0) {
290 /* XXX should be a generic interface for this */
291 AcpiOsWritePort(cpu_smi_cmd, cpu_pstate_cnt, 8);
296 /* set initial speed */
297 acpi_cpu_power_profile(NULL);
299 printf("acpi_cpu: throttling enabled, %d steps (100%% to %d.%d%%), "
300 "currently %d.%d%%\n", CPU_MAX_SPEED, CPU_SPEED_PRINTABLE(1),
301 CPU_SPEED_PRINTABLE(cpu_current_state));
305 * Set CPUs to the new state.
307 * Must be called with the ACPI lock held.
310 acpi_cpu_set_speed(u_int32_t speed)
312 struct acpi_cpu_softc *sc;
314 u_int32_t p_cnt, clk_val;
318 /* iterate over processors */
319 for (i = 0; i < cpu_ndevices; i++) {
320 sc = device_get_softc(cpu_devices[i]);
321 if (sc->cpu_p_blk == NULL)
324 /* get the current P_CNT value and disable throttling */
325 p_cnt = CPU_GET_P_CNT(sc);
326 p_cnt &= ~CPU_P_CNT_THT_EN;
327 CPU_SET_P_CNT(sc, p_cnt);
329 /* if we're at maximum speed, that's all */
330 if (speed < CPU_MAX_SPEED) {
332 /* mask the old CLK_VAL off and or-in the new value */
333 clk_val = CPU_MAX_SPEED << cpu_duty_offset;
335 p_cnt |= (speed << cpu_duty_offset);
337 /* write the new P_CNT value and then enable throttling */
338 CPU_SET_P_CNT(sc, p_cnt);
339 p_cnt |= CPU_P_CNT_THT_EN;
340 CPU_SET_P_CNT(sc, p_cnt);
342 ACPI_VPRINT(sc->cpu_dev, acpi_device_get_parent_softc(sc->cpu_dev),
343 "set speed to %d.%d%%\n", CPU_SPEED_PRINTABLE(speed));
345 cpu_current_state = speed;
349 * Power profile change hook.
351 * Uses the ACPI lock to avoid reentrancy.
354 acpi_cpu_power_profile(void *arg)
360 state = power_profile_get_state();
361 if (state != POWER_PROFILE_PERFORMANCE &&
362 state != POWER_PROFILE_ECONOMY) {
369 case POWER_PROFILE_PERFORMANCE:
370 new = cpu_performance_state;
372 case POWER_PROFILE_ECONOMY:
373 new = cpu_economy_state;
376 new = cpu_current_state;
380 if (cpu_current_state != new)
381 acpi_cpu_set_speed(new);
387 * Handle changes in the performance/ecomony CPU settings.
389 * Does not need the ACPI lock (although setting *argp should
390 * probably be atomic).
393 acpi_cpu_speed_sysctl(SYSCTL_HANDLER_ARGS)
399 argp = (u_int32_t *)oidp->oid_arg1;
401 error = sysctl_handle_int(oidp, &arg, 0, req);
403 /* error or no new value */
404 if ((error != 0) || (req->newptr == NULL))
408 if ((arg < 1) || (arg > cpu_max_state))
411 /* set new value and possibly switch */
413 acpi_cpu_power_profile(NULL);