Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

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 00000000000..05a17812d52
--- /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);
+}