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-rw-r--r--drivers/acpi/processor_idle.c1017
1 files changed, 1017 insertions, 0 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
new file mode 100644
index 000000000000..05a17812d521
--- /dev/null
+++ b/drivers/acpi/processor_idle.c
@@ -0,0 +1,1017 @@
+/*
+ * processor_idle - idle state submodule to the ACPI processor driver
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
+ * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ * - Added processor hotplug support
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/moduleparam.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include <acpi/acpi_bus.h>
+#include <acpi/processor.h>
+
+#define ACPI_PROCESSOR_COMPONENT 0x01000000
+#define ACPI_PROCESSOR_CLASS "processor"
+#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
+#define _COMPONENT ACPI_PROCESSOR_COMPONENT
+ACPI_MODULE_NAME ("acpi_processor")
+
+#define ACPI_PROCESSOR_FILE_POWER "power"
+
+#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
+#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
+#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
+
+static void (*pm_idle_save)(void);
+module_param(max_cstate, uint, 0644);
+
+static unsigned int nocst = 0;
+module_param(nocst, uint, 0000);
+
+/*
+ * bm_history -- bit-mask with a bit per jiffy of bus-master activity
+ * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
+ * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
+ * 100 HZ: 0x0000000F: 4 jiffies = 40ms
+ * reduce history for more aggressive entry into C3
+ */
+static unsigned int bm_history = (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
+module_param(bm_history, uint, 0644);
+/* --------------------------------------------------------------------------
+ Power Management
+ -------------------------------------------------------------------------- */
+
+/*
+ * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
+ * For now disable this. Probably a bug somewhere else.
+ *
+ * To skip this limit, boot/load with a large max_cstate limit.
+ */
+static int no_c2c3(struct dmi_system_id *id)
+{
+ if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
+ return 0;
+
+ printk(KERN_NOTICE PREFIX "%s detected - C2,C3 disabled."
+ " Override with \"processor.max_cstate=%d\"\n", id->ident,
+ ACPI_PROCESSOR_MAX_POWER + 1);
+
+ max_cstate = 1;
+
+ return 0;
+}
+
+
+
+
+static struct dmi_system_id __initdata processor_power_dmi_table[] = {
+ { no_c2c3, "IBM ThinkPad R40e", {
+ DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
+ DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }},
+ { no_c2c3, "Medion 41700", {
+ DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
+ DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J") }},
+ {},
+};
+
+
+static inline u32
+ticks_elapsed (
+ u32 t1,
+ u32 t2)
+{
+ if (t2 >= t1)
+ return (t2 - t1);
+ else if (!acpi_fadt.tmr_val_ext)
+ return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
+ else
+ return ((0xFFFFFFFF - t1) + t2);
+}
+
+
+static void
+acpi_processor_power_activate (
+ struct acpi_processor *pr,
+ struct acpi_processor_cx *new)
+{
+ struct acpi_processor_cx *old;
+
+ if (!pr || !new)
+ return;
+
+ old = pr->power.state;
+
+ if (old)
+ old->promotion.count = 0;
+ new->demotion.count = 0;
+
+ /* Cleanup from old state. */
+ if (old) {
+ switch (old->type) {
+ case ACPI_STATE_C3:
+ /* Disable bus master reload */
+ if (new->type != ACPI_STATE_C3)
+ acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0, ACPI_MTX_DO_NOT_LOCK);
+ break;
+ }
+ }
+
+ /* Prepare to use new state. */
+ switch (new->type) {
+ case ACPI_STATE_C3:
+ /* Enable bus master reload */
+ if (old->type != ACPI_STATE_C3)
+ acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1, ACPI_MTX_DO_NOT_LOCK);
+ break;
+ }
+
+ pr->power.state = new;
+
+ return;
+}
+
+
+static void acpi_processor_idle (void)
+{
+ struct acpi_processor *pr = NULL;
+ struct acpi_processor_cx *cx = NULL;
+ struct acpi_processor_cx *next_state = NULL;
+ int sleep_ticks = 0;
+ u32 t1, t2 = 0;
+
+ pr = processors[_smp_processor_id()];
+ if (!pr)
+ return;
+
+ /*
+ * Interrupts must be disabled during bus mastering calculations and
+ * for C2/C3 transitions.
+ */
+ local_irq_disable();
+
+ /*
+ * Check whether we truly need to go idle, or should
+ * reschedule:
+ */
+ if (unlikely(need_resched())) {
+ local_irq_enable();
+ return;
+ }
+
+ cx = pr->power.state;
+ if (!cx)
+ goto easy_out;
+
+ /*
+ * Check BM Activity
+ * -----------------
+ * Check for bus mastering activity (if required), record, and check
+ * for demotion.
+ */
+ if (pr->flags.bm_check) {
+ u32 bm_status = 0;
+ unsigned long diff = jiffies - pr->power.bm_check_timestamp;
+
+ if (diff > 32)
+ diff = 32;
+
+ while (diff) {
+ /* if we didn't get called, assume there was busmaster activity */
+ diff--;
+ if (diff)
+ pr->power.bm_activity |= 0x1;
+ pr->power.bm_activity <<= 1;
+ }
+
+ acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS,
+ &bm_status, ACPI_MTX_DO_NOT_LOCK);
+ if (bm_status) {
+ pr->power.bm_activity++;
+ acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
+ 1, ACPI_MTX_DO_NOT_LOCK);
+ }
+ /*
+ * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
+ * the true state of bus mastering activity; forcing us to
+ * manually check the BMIDEA bit of each IDE channel.
+ */
+ else if (errata.piix4.bmisx) {
+ if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
+ || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
+ pr->power.bm_activity++;
+ }
+
+ pr->power.bm_check_timestamp = jiffies;
+
+ /*
+ * Apply bus mastering demotion policy. Automatically demote
+ * to avoid a faulty transition. Note that the processor
+ * won't enter a low-power state during this call (to this
+ * funciton) but should upon the next.
+ *
+ * TBD: A better policy might be to fallback to the demotion
+ * state (use it for this quantum only) istead of
+ * demoting -- and rely on duration as our sole demotion
+ * qualification. This may, however, introduce DMA
+ * issues (e.g. floppy DMA transfer overrun/underrun).
+ */
+ if (pr->power.bm_activity & cx->demotion.threshold.bm) {
+ local_irq_enable();
+ next_state = cx->demotion.state;
+ goto end;
+ }
+ }
+
+ cx->usage++;
+
+ /*
+ * Sleep:
+ * ------
+ * Invoke the current Cx state to put the processor to sleep.
+ */
+ switch (cx->type) {
+
+ case ACPI_STATE_C1:
+ /*
+ * Invoke C1.
+ * Use the appropriate idle routine, the one that would
+ * be used without acpi C-states.
+ */
+ if (pm_idle_save)
+ pm_idle_save();
+ else
+ safe_halt();
+ /*
+ * TBD: Can't get time duration while in C1, as resumes
+ * go to an ISR rather than here. Need to instrument
+ * base interrupt handler.
+ */
+ sleep_ticks = 0xFFFFFFFF;
+ break;
+
+ case ACPI_STATE_C2:
+ /* Get start time (ticks) */
+ t1 = inl(acpi_fadt.xpm_tmr_blk.address);
+ /* Invoke C2 */
+ inb(cx->address);
+ /* Dummy op - must do something useless after P_LVL2 read */
+ t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ /* Get end time (ticks) */
+ t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ /* Re-enable interrupts */
+ local_irq_enable();
+ /* Compute time (ticks) that we were actually asleep */
+ sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
+ break;
+
+ case ACPI_STATE_C3:
+ /* Disable bus master arbitration */
+ acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1, ACPI_MTX_DO_NOT_LOCK);
+ /* Get start time (ticks) */
+ t1 = inl(acpi_fadt.xpm_tmr_blk.address);
+ /* Invoke C3 */
+ inb(cx->address);
+ /* Dummy op - must do something useless after P_LVL3 read */
+ t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ /* Get end time (ticks) */
+ t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ /* Enable bus master arbitration */
+ acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, ACPI_MTX_DO_NOT_LOCK);
+ /* Re-enable interrupts */
+ local_irq_enable();
+ /* Compute time (ticks) that we were actually asleep */
+ sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
+ break;
+
+ default:
+ local_irq_enable();
+ return;
+ }
+
+ next_state = pr->power.state;
+
+ /*
+ * Promotion?
+ * ----------
+ * Track the number of longs (time asleep is greater than threshold)
+ * and promote when the count threshold is reached. Note that bus
+ * mastering activity may prevent promotions.
+ * Do not promote above max_cstate.
+ */
+ if (cx->promotion.state &&
+ ((cx->promotion.state - pr->power.states) <= max_cstate)) {
+ if (sleep_ticks > cx->promotion.threshold.ticks) {
+ cx->promotion.count++;
+ cx->demotion.count = 0;
+ if (cx->promotion.count >= cx->promotion.threshold.count) {
+ if (pr->flags.bm_check) {
+ if (!(pr->power.bm_activity & cx->promotion.threshold.bm)) {
+ next_state = cx->promotion.state;
+ goto end;
+ }
+ }
+ else {
+ next_state = cx->promotion.state;
+ goto end;
+ }
+ }
+ }
+ }
+
+ /*
+ * Demotion?
+ * ---------
+ * Track the number of shorts (time asleep is less than time threshold)
+ * and demote when the usage threshold is reached.
+ */
+ if (cx->demotion.state) {
+ if (sleep_ticks < cx->demotion.threshold.ticks) {
+ cx->demotion.count++;
+ cx->promotion.count = 0;
+ if (cx->demotion.count >= cx->demotion.threshold.count) {
+ next_state = cx->demotion.state;
+ goto end;
+ }
+ }
+ }
+
+end:
+ /*
+ * Demote if current state exceeds max_cstate
+ */
+ if ((pr->power.state - pr->power.states) > max_cstate) {
+ if (cx->demotion.state)
+ next_state = cx->demotion.state;
+ }
+
+ /*
+ * New Cx State?
+ * -------------
+ * If we're going to start using a new Cx state we must clean up
+ * from the previous and prepare to use the new.
+ */
+ if (next_state != pr->power.state)
+ acpi_processor_power_activate(pr, next_state);
+
+ return;
+
+ easy_out:
+ /* do C1 instead of busy loop */
+ if (pm_idle_save)
+ pm_idle_save();
+ else
+ safe_halt();
+ return;
+}
+
+
+static int
+acpi_processor_set_power_policy (
+ struct acpi_processor *pr)
+{
+ unsigned int i;
+ unsigned int state_is_set = 0;
+ struct acpi_processor_cx *lower = NULL;
+ struct acpi_processor_cx *higher = NULL;
+ struct acpi_processor_cx *cx;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");
+
+ if (!pr)
+ return_VALUE(-EINVAL);
+
+ /*
+ * This function sets the default Cx state policy (OS idle handler).
+ * Our scheme is to promote quickly to C2 but more conservatively
+ * to C3. We're favoring C2 for its characteristics of low latency
+ * (quick response), good power savings, and ability to allow bus
+ * mastering activity. Note that the Cx state policy is completely
+ * customizable and can be altered dynamically.
+ */
+
+ /* startup state */
+ for (i=1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
+ cx = &pr->power.states[i];
+ if (!cx->valid)
+ continue;
+
+ if (!state_is_set)
+ pr->power.state = cx;
+ state_is_set++;
+ break;
+ }
+
+ if (!state_is_set)
+ return_VALUE(-ENODEV);
+
+ /* demotion */
+ for (i=1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
+ cx = &pr->power.states[i];
+ if (!cx->valid)
+ continue;
+
+ if (lower) {
+ cx->demotion.state = lower;
+ cx->demotion.threshold.ticks = cx->latency_ticks;
+ cx->demotion.threshold.count = 1;
+ if (cx->type == ACPI_STATE_C3)
+ cx->demotion.threshold.bm = bm_history;
+ }
+
+ lower = cx;
+ }
+
+ /* promotion */
+ for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
+ cx = &pr->power.states[i];
+ if (!cx->valid)
+ continue;
+
+ if (higher) {
+ cx->promotion.state = higher;
+ cx->promotion.threshold.ticks = cx->latency_ticks;
+ if (cx->type >= ACPI_STATE_C2)
+ cx->promotion.threshold.count = 4;
+ else
+ cx->promotion.threshold.count = 10;
+ if (higher->type == ACPI_STATE_C3)
+ cx->promotion.threshold.bm = bm_history;
+ }
+
+ higher = cx;
+ }
+
+ return_VALUE(0);
+}
+
+
+static int acpi_processor_get_power_info_fadt (struct acpi_processor *pr)
+{
+ int i;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_fadt");
+
+ if (!pr)
+ return_VALUE(-EINVAL);
+
+ if (!pr->pblk)
+ return_VALUE(-ENODEV);
+
+ for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
+ memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
+
+ /* if info is obtained from pblk/fadt, type equals state */
+ pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
+ pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
+ pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
+
+ /* the C0 state only exists as a filler in our array,
+ * and all processors need to support C1 */
+ pr->power.states[ACPI_STATE_C0].valid = 1;
+ pr->power.states[ACPI_STATE_C1].valid = 1;
+
+ /* determine C2 and C3 address from pblk */
+ pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
+ pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
+
+ /* determine latencies from FADT */
+ pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;
+ pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;
+
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "lvl2[0x%08x] lvl3[0x%08x]\n",
+ pr->power.states[ACPI_STATE_C2].address,
+ pr->power.states[ACPI_STATE_C3].address));
+
+ return_VALUE(0);
+}
+
+
+static int acpi_processor_get_power_info_cst (struct acpi_processor *pr)
+{
+ acpi_status status = 0;
+ acpi_integer count;
+ int i;
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+ union acpi_object *cst;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_get_power_info_cst");
+
+ if (errata.smp)
+ return_VALUE(-ENODEV);
+
+ if (nocst)
+ return_VALUE(-ENODEV);
+
+ pr->power.count = 0;
+ for (i = 0; i < ACPI_PROCESSOR_MAX_POWER; i++)
+ memset(pr->power.states, 0, sizeof(struct acpi_processor_cx));
+
+ status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
+ if (ACPI_FAILURE(status)) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
+ return_VALUE(-ENODEV);
+ }
+
+ cst = (union acpi_object *) buffer.pointer;
+
+ /* There must be at least 2 elements */
+ if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "not enough elements in _CST\n"));
+ status = -EFAULT;
+ goto end;
+ }
+
+ count = cst->package.elements[0].integer.value;
+
+ /* Validate number of power states. */
+ if (count < 1 || count != cst->package.count - 1) {
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "count given by _CST is not valid\n"));
+ status = -EFAULT;
+ goto end;
+ }
+
+ /* We support up to ACPI_PROCESSOR_MAX_POWER. */
+ if (count > ACPI_PROCESSOR_MAX_POWER) {
+ printk(KERN_WARNING "Limiting number of power states to max (%d)\n", ACPI_PROCESSOR_MAX_POWER);
+ printk(KERN_WARNING "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
+ count = ACPI_PROCESSOR_MAX_POWER;
+ }
+
+ /* Tell driver that at least _CST is supported. */
+ pr->flags.has_cst = 1;
+
+ for (i = 1; i <= count; i++) {
+ union acpi_object *element;
+ union acpi_object *obj;
+ struct acpi_power_register *reg;
+ struct acpi_processor_cx cx;
+
+ memset(&cx, 0, sizeof(cx));
+
+ element = (union acpi_object *) &(cst->package.elements[i]);
+ if (element->type != ACPI_TYPE_PACKAGE)
+ continue;
+
+ if (element->package.count != 4)
+ continue;
+
+ obj = (union acpi_object *) &(element->package.elements[0]);
+
+ if (obj->type != ACPI_TYPE_BUFFER)
+ continue;
+
+ reg = (struct acpi_power_register *) obj->buffer.pointer;
+
+ if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
+ (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
+ continue;
+
+ cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
+ 0 : reg->address;
+
+ /* There should be an easy way to extract an integer... */
+ obj = (union acpi_object *) &(element->package.elements[1]);
+ if (obj->type != ACPI_TYPE_INTEGER)
+ continue;
+
+ cx.type = obj->integer.value;
+
+ if ((cx.type != ACPI_STATE_C1) &&
+ (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
+ continue;
+
+ if ((cx.type < ACPI_STATE_C1) ||
+ (cx.type > ACPI_STATE_C3))
+ continue;
+
+ obj = (union acpi_object *) &(element->package.elements[2]);
+ if (obj->type != ACPI_TYPE_INTEGER)
+ continue;
+
+ cx.latency = obj->integer.value;
+
+ obj = (union acpi_object *) &(element->package.elements[3]);
+ if (obj->type != ACPI_TYPE_INTEGER)
+ continue;
+
+ cx.power = obj->integer.value;
+
+ (pr->power.count)++;
+ memcpy(&(pr->power.states[pr->power.count]), &cx, sizeof(cx));
+ }
+
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n", pr->power.count));
+
+ /* Validate number of power states discovered */
+ if (pr->power.count < 2)
+ status = -ENODEV;
+
+end:
+ acpi_os_free(buffer.pointer);
+
+ return_VALUE(status);
+}
+
+
+static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
+{
+ ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c2");
+
+ if (!cx->address)
+ return_VOID;
+
+ /*
+ * C2 latency must be less than or equal to 100
+ * microseconds.
+ */
+ else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "latency too large [%d]\n",
+ cx->latency));
+ return_VOID;
+ }
+
+ /* We're (currently) only supporting C2 on UP */
+ else if (errata.smp) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "C2 not supported in SMP mode\n"));
+ return_VOID;
+ }
+
+ /*
+ * Otherwise we've met all of our C2 requirements.
+ * Normalize the C2 latency to expidite policy
+ */
+ cx->valid = 1;
+ cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
+
+ return_VOID;
+}
+
+
+static void acpi_processor_power_verify_c3(
+ struct acpi_processor *pr,
+ struct acpi_processor_cx *cx)
+{
+ ACPI_FUNCTION_TRACE("acpi_processor_get_power_verify_c3");
+
+ if (!cx->address)
+ return_VOID;
+
+ /*
+ * C3 latency must be less than or equal to 1000
+ * microseconds.
+ */
+ else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "latency too large [%d]\n",
+ cx->latency));
+ return_VOID;
+ }
+
+ /* bus mastering control is necessary */
+ else if (!pr->flags.bm_control) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "C3 support requires bus mastering control\n"));
+ return_VOID;
+ }
+
+ /* We're (currently) only supporting C2 on UP */
+ else if (errata.smp) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "C3 not supported in SMP mode\n"));
+ return_VOID;
+ }
+
+ /*
+ * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
+ * DMA transfers are used by any ISA device to avoid livelock.
+ * Note that we could disable Type-F DMA (as recommended by
+ * the erratum), but this is known to disrupt certain ISA
+ * devices thus we take the conservative approach.
+ */
+ else if (errata.piix4.fdma) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "C3 not supported on PIIX4 with Type-F DMA\n"));
+ return_VOID;
+ }
+
+ /*
+ * Otherwise we've met all of our C3 requirements.
+ * Normalize the C3 latency to expidite policy. Enable
+ * checking of bus mastering status (bm_check) so we can
+ * use this in our C3 policy
+ */
+ cx->valid = 1;
+ cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
+ pr->flags.bm_check = 1;
+
+ return_VOID;
+}
+
+
+static int acpi_processor_power_verify(struct acpi_processor *pr)
+{
+ unsigned int i;
+ unsigned int working = 0;
+
+ for (i=1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
+ struct acpi_processor_cx *cx = &pr->power.states[i];
+
+ switch (cx->type) {
+ case ACPI_STATE_C1:
+ cx->valid = 1;
+ break;
+
+ case ACPI_STATE_C2:
+ acpi_processor_power_verify_c2(cx);
+ break;
+
+ case ACPI_STATE_C3:
+ acpi_processor_power_verify_c3(pr, cx);
+ break;
+ }
+
+ if (cx->valid)
+ working++;
+ }
+
+ return (working);
+}
+
+static int acpi_processor_get_power_info (
+ struct acpi_processor *pr)
+{
+ unsigned int i;
+ int result;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");
+
+ /* NOTE: the idle thread may not be running while calling
+ * this function */
+
+ result = acpi_processor_get_power_info_cst(pr);
+ if ((result) || (acpi_processor_power_verify(pr) < 2)) {
+ result = acpi_processor_get_power_info_fadt(pr);
+ if (result)
+ return_VALUE(result);
+
+ if (acpi_processor_power_verify(pr) < 2)
+ return_VALUE(-ENODEV);
+ }
+
+ /*
+ * Set Default Policy
+ * ------------------
+ * Now that we know which states are supported, set the default
+ * policy. Note that this policy can be changed dynamically
+ * (e.g. encourage deeper sleeps to conserve battery life when
+ * not on AC).
+ */
+ result = acpi_processor_set_power_policy(pr);
+ if (result)
+ return_VALUE(result);
+
+ /*
+ * if one state of type C2 or C3 is available, mark this
+ * CPU as being "idle manageable"
+ */
+ for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
+ if (pr->power.states[i].valid)
+ pr->power.count = i;
+ if ((pr->power.states[i].valid) &&
+ (pr->power.states[i].type >= ACPI_STATE_C2))
+ pr->flags.power = 1;
+ }
+
+ return_VALUE(0);
+}
+
+int acpi_processor_cst_has_changed (struct acpi_processor *pr)
+{
+ int result = 0;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_cst_has_changed");
+
+ if (!pr)
+ return_VALUE(-EINVAL);
+
+ if (errata.smp || nocst) {
+ return_VALUE(-ENODEV);
+ }
+
+ if (!pr->flags.power_setup_done)
+ return_VALUE(-ENODEV);
+
+ /* Fall back to the default idle loop */
+ pm_idle = pm_idle_save;
+ synchronize_kernel();
+
+ pr->flags.power = 0;
+ result = acpi_processor_get_power_info(pr);
+ if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
+ pm_idle = acpi_processor_idle;
+
+ return_VALUE(result);
+}
+
+/* proc interface */
+
+static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
+{
+ struct acpi_processor *pr = (struct acpi_processor *)seq->private;
+ unsigned int i;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_power_seq_show");
+
+ if (!pr)
+ goto end;
+
+ seq_printf(seq, "active state: C%zd\n"
+ "max_cstate: C%d\n"
+ "bus master activity: %08x\n",
+ pr->power.state ? pr->power.state - pr->power.states : 0,
+ max_cstate,
+ (unsigned)pr->power.bm_activity);
+
+ seq_puts(seq, "states:\n");
+
+ for (i = 1; i <= pr->power.count; i++) {
+ seq_printf(seq, " %cC%d: ",
+ (&pr->power.states[i] == pr->power.state?'*':' '), i);
+
+ if (!pr->power.states[i].valid) {
+ seq_puts(seq, "<not supported>\n");
+ continue;
+ }
+
+ switch (pr->power.states[i].type) {
+ case ACPI_STATE_C1:
+ seq_printf(seq, "type[C1] ");
+ break;
+ case ACPI_STATE_C2:
+ seq_printf(seq, "type[C2] ");
+ break;
+ case ACPI_STATE_C3:
+ seq_printf(seq, "type[C3] ");
+ break;
+ default:
+ seq_printf(seq, "type[--] ");
+ break;
+ }
+
+ if (pr->power.states[i].promotion.state)
+ seq_printf(seq, "promotion[C%zd] ",
+ (pr->power.states[i].promotion.state -
+ pr->power.states));
+ else
+ seq_puts(seq, "promotion[--] ");
+
+ if (pr->power.states[i].demotion.state)
+ seq_printf(seq, "demotion[C%zd] ",
+ (pr->power.states[i].demotion.state -
+ pr->power.states));
+ else
+ seq_puts(seq, "demotion[--] ");
+
+ seq_printf(seq, "latency[%03d] usage[%08d]\n",
+ pr->power.states[i].latency,
+ pr->power.states[i].usage);
+ }
+
+end:
+ return_VALUE(0);
+}
+
+static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
+{
+ return single_open(file, acpi_processor_power_seq_show,
+ PDE(inode)->data);
+}
+
+static struct file_operations acpi_processor_power_fops = {
+ .open = acpi_processor_power_open_fs,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+
+int acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *device)
+{
+ acpi_status status = 0;
+ static int first_run = 0;
+ struct proc_dir_entry *entry = NULL;
+ unsigned int i;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_power_init");
+
+ if (!first_run) {
+ dmi_check_system(processor_power_dmi_table);
+ if (max_cstate < ACPI_C_STATES_MAX)
+ printk(KERN_NOTICE "ACPI: processor limited to max C-state %d\n", max_cstate);
+ first_run++;
+ }
+
+ if (!errata.smp && (pr->id == 0) && acpi_fadt.cst_cnt && !nocst) {
+ status = acpi_os_write_port(acpi_fadt.smi_cmd, acpi_fadt.cst_cnt, 8);
+ if (ACPI_FAILURE(status)) {
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+ "Notifying BIOS of _CST ability failed\n"));
+ }
+ }
+
+ acpi_processor_get_power_info(pr);
+
+ /*
+ * Install the idle handler if processor power management is supported.
+ * Note that we use previously set idle handler will be used on
+ * platforms that only support C1.
+ */
+ if ((pr->flags.power) && (!boot_option_idle_override)) {
+ printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
+ for (i = 1; i <= pr->power.count; i++)
+ if (pr->power.states[i].valid)
+ printk(" C%d[C%d]", i, pr->power.states[i].type);
+ printk(")\n");
+
+ if (pr->id == 0) {
+ pm_idle_save = pm_idle;
+ pm_idle = acpi_processor_idle;
+ }
+ }
+
+ /* 'power' [R] */
+ entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
+ S_IRUGO, acpi_device_dir(device));
+ if (!entry)
+ ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+ "Unable to create '%s' fs entry\n",
+ ACPI_PROCESSOR_FILE_POWER));
+ else {
+ entry->proc_fops = &acpi_processor_power_fops;
+ entry->data = acpi_driver_data(device);
+ entry->owner = THIS_MODULE;
+ }
+
+ pr->flags.power_setup_done = 1;
+
+ return_VALUE(0);
+}
+
+int acpi_processor_power_exit(struct acpi_processor *pr, struct acpi_device *device)
+{
+ ACPI_FUNCTION_TRACE("acpi_processor_power_exit");
+
+ pr->flags.power_setup_done = 0;
+
+ if (acpi_device_dir(device))
+ remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,acpi_device_dir(device));
+
+ /* Unregister the idle handler when processor #0 is removed. */
+ if (pr->id == 0) {
+ pm_idle = pm_idle_save;
+
+ /*
+ * We are about to unload the current idle thread pm callback
+ * (pm_idle), Wait for all processors to update cached/local
+ * copies of pm_idle before proceeding.
+ */
+ cpu_idle_wait();
+ }
+
+ return_VALUE(0);
+}