Initial import

4 files changed, 1749 insertions, 0 deletions

diff --git a/drivers/idle/Kconfig b/drivers/idle/Kconfig
new file mode 100644
index 000000000..4732dfc15
--- /dev/null
+++ b/drivers/idle/Kconfig
@@ -0,0 +1,27 @@
+config INTEL_IDLE
+	bool "Cpuidle Driver for Intel Processors"
+	depends on CPU_IDLE
+	depends on X86
+	depends on CPU_SUP_INTEL
+	help
+	  Enable intel_idle, a cpuidle driver that includes knowledge of
+	  native Intel hardware idle features.  The acpi_idle driver
+	  can be configured at the same time, in order to handle
+	  processors intel_idle does not support.
+
+menu "Memory power savings"
+depends on X86_64
+
+config I7300_IDLE_IOAT_CHANNEL
+	bool
+
+config I7300_IDLE
+	tristate "Intel chipset idle memory power saving driver"
+	select I7300_IDLE_IOAT_CHANNEL
+	help
+	  Enable memory power savings when idle with certain Intel server
+	  chipsets. The chipset must have I/O AT support, such as the
+	  Intel 7300. The power savings depends on the type and quantity of
+	  DRAM devices.
+
+endmenu
diff --git a/drivers/idle/Makefile b/drivers/idle/Makefile
new file mode 100644
index 000000000..23d295cf1
--- /dev/null
+++ b/drivers/idle/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_I7300_IDLE)			+= i7300_idle.o
+obj-$(CONFIG_INTEL_IDLE)			+= intel_idle.o
+
diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c
new file mode 100644
index 000000000..ffeebc7e9
--- /dev/null
+++ b/drivers/idle/i7300_idle.c
@@ -0,0 +1,612 @@
+/*
+ * (C) Copyright 2008 Intel Corporation
+ * Authors:
+ * Andy Henroid <andrew.d.henroid@intel.com>
+ * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ */
+
+/*
+ * Save DIMM power on Intel 7300-based platforms when all CPUs/cores
+ * are idle, using the DIMM thermal throttling capability.
+ *
+ * This driver depends on the Intel integrated DMA controller (I/O AT).
+ * If the driver for I/O AT (drivers/dma/ioatdma*) is also enabled,
+ * this driver should work cooperatively.
+ */
+
+/* #define DEBUG */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/gfp.h>
+#include <linux/sched.h>
+#include <linux/notifier.h>
+#include <linux/cpumask.h>
+#include <linux/ktime.h>
+#include <linux/delay.h>
+#include <linux/debugfs.h>
+#include <linux/stop_machine.h>
+#include <linux/i7300_idle.h>
+
+#include <asm/idle.h>
+
+#include "../dma/ioat/hw.h"
+#include "../dma/ioat/registers.h"
+
+#define I7300_IDLE_DRIVER_VERSION	"1.55"
+#define I7300_PRINT			"i7300_idle:"
+
+#define MAX_STOP_RETRIES	10
+
+static int debug;
+module_param_named(debug, debug, uint, 0644);
+MODULE_PARM_DESC(debug, "Enable debug printks in this driver");
+
+static int forceload;
+module_param_named(forceload, forceload, uint, 0644);
+MODULE_PARM_DESC(debug, "Enable driver testing on unvalidated i5000");
+
+#define dprintk(fmt, arg...) \
+	do { if (debug) printk(KERN_INFO I7300_PRINT fmt, ##arg); } while (0)
+
+/*
+ * Value to set THRTLOW to when initiating throttling
+ *  0 = No throttling
+ *  1 = Throttle when > 4 activations per eval window (Maximum throttling)
+ *  2 = Throttle when > 8 activations
+ *  168 = Throttle when > 672 activations (Minimum throttling)
+ */
+#define MAX_THROTTLE_LOW_LIMIT		168
+static uint throttle_low_limit = 1;
+module_param_named(throttle_low_limit, throttle_low_limit, uint, 0644);
+MODULE_PARM_DESC(throttle_low_limit,
+		"Value for THRTLOWLM activation field "
+		"(0 = disable throttle, 1 = Max throttle, 168 = Min throttle)");
+
+/*
+ * simple invocation and duration statistics
+ */
+static unsigned long total_starts;
+static unsigned long total_us;
+
+#ifdef DEBUG
+static unsigned long past_skip;
+#endif
+
+static struct pci_dev *fbd_dev;
+
+static raw_spinlock_t i7300_idle_lock;
+static int i7300_idle_active;
+
+static u8 i7300_idle_thrtctl_saved;
+static u8 i7300_idle_thrtlow_saved;
+static u32 i7300_idle_mc_saved;
+
+static cpumask_var_t idle_cpumask;
+static ktime_t start_ktime;
+static unsigned long avg_idle_us;
+
+static struct dentry *debugfs_dir;
+
+/* Begin: I/O AT Helper routines */
+
+#define IOAT_CHANBASE(ioat_ctl, chan) (ioat_ctl + 0x80 + 0x80 * chan)
+/* Snoop control (disable snoops when coherency is not important) */
+#define IOAT_DESC_SADDR_SNP_CTL (1UL << 1)
+#define IOAT_DESC_DADDR_SNP_CTL (1UL << 2)
+
+static struct pci_dev *ioat_dev;
+static struct ioat_dma_descriptor *ioat_desc; /* I/O AT desc & data (1 page) */
+static unsigned long ioat_desc_phys;
+static u8 *ioat_iomap; /* I/O AT memory-mapped control regs (aka CB_BAR) */
+static u8 *ioat_chanbase;
+
+/* Start I/O AT memory copy */
+static int i7300_idle_ioat_start(void)
+{
+	u32 err;
+	/* Clear error (due to circular descriptor pointer) */
+	err = readl(ioat_chanbase + IOAT_CHANERR_OFFSET);
+	if (err)
+		writel(err, ioat_chanbase + IOAT_CHANERR_OFFSET);
+
+	writeb(IOAT_CHANCMD_START, ioat_chanbase + IOAT1_CHANCMD_OFFSET);
+	return 0;
+}
+
+/* Stop I/O AT memory copy */
+static void i7300_idle_ioat_stop(void)
+{
+	int i;
+	u64 sts;
+
+	for (i = 0; i < MAX_STOP_RETRIES; i++) {
+		writeb(IOAT_CHANCMD_RESET,
+			ioat_chanbase + IOAT1_CHANCMD_OFFSET);
+
+		udelay(10);
+
+		sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
+			IOAT_CHANSTS_STATUS;
+
+		if (sts != IOAT_CHANSTS_ACTIVE)
+			break;
+
+	}
+
+	if (i == MAX_STOP_RETRIES) {
+		dprintk("failed to stop I/O AT after %d retries\n",
+			MAX_STOP_RETRIES);
+	}
+}
+
+/* Test I/O AT by copying 1024 byte from 2k to 1k */
+static int __init i7300_idle_ioat_selftest(u8 *ctl,
+		struct ioat_dma_descriptor *desc, unsigned long desc_phys)
+{
+	u64 chan_sts;
+
+	memset(desc, 0, 2048);
+	memset((u8 *) desc + 2048, 0xab, 1024);
+
+	desc[0].size = 1024;
+	desc[0].ctl = 0;
+	desc[0].src_addr = desc_phys + 2048;
+	desc[0].dst_addr = desc_phys + 1024;
+	desc[0].next = 0;
+
+	writeb(IOAT_CHANCMD_RESET, ioat_chanbase + IOAT1_CHANCMD_OFFSET);
+	writeb(IOAT_CHANCMD_START, ioat_chanbase + IOAT1_CHANCMD_OFFSET);
+
+	udelay(1000);
+
+	chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
+			IOAT_CHANSTS_STATUS;
+
+	if (chan_sts != IOAT_CHANSTS_DONE) {
+		/* Not complete, reset the channel */
+		writeb(IOAT_CHANCMD_RESET,
+		       ioat_chanbase + IOAT1_CHANCMD_OFFSET);
+		return -1;
+	}
+
+	if (*(u32 *) ((u8 *) desc + 3068) != 0xabababab ||
+	    *(u32 *) ((u8 *) desc + 2044) != 0xabababab) {
+		dprintk("Data values src 0x%x, dest 0x%x, memset 0x%x\n",
+			*(u32 *) ((u8 *) desc + 2048),
+			*(u32 *) ((u8 *) desc + 1024),
+			*(u32 *) ((u8 *) desc + 3072));
+		return -1;
+	}
+	return 0;
+}
+
+static struct device dummy_dma_dev = {
+	.init_name = "fallback device",
+	.coherent_dma_mask = DMA_BIT_MASK(64),
+	.dma_mask = &dummy_dma_dev.coherent_dma_mask,
+};
+
+/* Setup and initialize I/O AT */
+/* This driver needs I/O AT as the throttling takes effect only when there is
+ * some memory activity. We use I/O AT to set up a dummy copy, while all CPUs
+ * go idle and memory is throttled.
+ */
+static int __init i7300_idle_ioat_init(void)
+{
+	u8 ver, chan_count, ioat_chan;
+	u16 chan_ctl;
+
+	ioat_iomap = (u8 *) ioremap_nocache(pci_resource_start(ioat_dev, 0),
+					    pci_resource_len(ioat_dev, 0));
+
+	if (!ioat_iomap) {
+		printk(KERN_ERR I7300_PRINT "failed to map I/O AT registers\n");
+		goto err_ret;
+	}
+
+	ver = readb(ioat_iomap + IOAT_VER_OFFSET);
+	if (ver != IOAT_VER_1_2) {
+		printk(KERN_ERR I7300_PRINT "unknown I/O AT version (%u.%u)\n",
+			ver >> 4, ver & 0xf);
+		goto err_unmap;
+	}
+
+	chan_count = readb(ioat_iomap + IOAT_CHANCNT_OFFSET);
+	if (!chan_count) {
+		printk(KERN_ERR I7300_PRINT "unexpected # of I/O AT channels "
+			"(%u)\n",
+			chan_count);
+		goto err_unmap;
+	}
+
+	ioat_chan = chan_count - 1;
+	ioat_chanbase = IOAT_CHANBASE(ioat_iomap, ioat_chan);
+
+	chan_ctl = readw(ioat_chanbase + IOAT_CHANCTRL_OFFSET);
+	if (chan_ctl & IOAT_CHANCTRL_CHANNEL_IN_USE) {
+		printk(KERN_ERR I7300_PRINT "channel %d in use\n", ioat_chan);
+		goto err_unmap;
+	}
+
+	writew(IOAT_CHANCTRL_CHANNEL_IN_USE,
+		ioat_chanbase + IOAT_CHANCTRL_OFFSET);
+
+	ioat_desc = (struct ioat_dma_descriptor *)dma_alloc_coherent(
+			&dummy_dma_dev, 4096,
+			(dma_addr_t *)&ioat_desc_phys, GFP_KERNEL);
+	if (!ioat_desc) {
+		printk(KERN_ERR I7300_PRINT "failed to allocate I/O AT desc\n");
+		goto err_mark_unused;
+	}
+
+	writel(ioat_desc_phys & 0xffffffffUL,
+	       ioat_chanbase + IOAT1_CHAINADDR_OFFSET_LOW);
+	writel(ioat_desc_phys >> 32,
+	       ioat_chanbase + IOAT1_CHAINADDR_OFFSET_HIGH);
+
+	if (i7300_idle_ioat_selftest(ioat_iomap, ioat_desc, ioat_desc_phys)) {
+		printk(KERN_ERR I7300_PRINT "I/O AT self-test failed\n");
+		goto err_free;
+	}
+
+	/* Setup circular I/O AT descriptor chain */
+	ioat_desc[0].ctl = IOAT_DESC_SADDR_SNP_CTL | IOAT_DESC_DADDR_SNP_CTL;
+	ioat_desc[0].src_addr = ioat_desc_phys + 2048;
+	ioat_desc[0].dst_addr = ioat_desc_phys + 3072;
+	ioat_desc[0].size = 128;
+	ioat_desc[0].next = ioat_desc_phys + sizeof(struct ioat_dma_descriptor);
+
+	ioat_desc[1].ctl = ioat_desc[0].ctl;
+	ioat_desc[1].src_addr = ioat_desc[0].src_addr;
+	ioat_desc[1].dst_addr = ioat_desc[0].dst_addr;
+	ioat_desc[1].size = ioat_desc[0].size;
+	ioat_desc[1].next = ioat_desc_phys;
+
+	return 0;
+
+err_free:
+	dma_free_coherent(&dummy_dma_dev, 4096, (void *)ioat_desc, 0);
+err_mark_unused:
+	writew(0, ioat_chanbase + IOAT_CHANCTRL_OFFSET);
+err_unmap:
+	iounmap(ioat_iomap);
+err_ret:
+	return -ENODEV;
+}
+
+/* Cleanup I/O AT */
+static void __exit i7300_idle_ioat_exit(void)
+{
+	int i;
+	u64 chan_sts;
+
+	i7300_idle_ioat_stop();
+
+	/* Wait for a while for the channel to halt before releasing */
+	for (i = 0; i < MAX_STOP_RETRIES; i++) {
+		writeb(IOAT_CHANCMD_RESET,
+		       ioat_chanbase + IOAT1_CHANCMD_OFFSET);
+
+		chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
+			IOAT_CHANSTS_STATUS;
+
+		if (chan_sts != IOAT_CHANSTS_ACTIVE) {
+			writew(0, ioat_chanbase + IOAT_CHANCTRL_OFFSET);
+			break;
+		}
+		udelay(1000);
+	}
+
+	chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
+			IOAT_CHANSTS_STATUS;
+
+	/*
+	 * We tried to reset multiple times. If IO A/T channel is still active
+	 * flag an error and return without cleanup. Memory leak is better
+	 * than random corruption in that extreme error situation.
+	 */
+	if (chan_sts == IOAT_CHANSTS_ACTIVE) {
+		printk(KERN_ERR I7300_PRINT "Unable to stop IO A/T channels."
+			" Not freeing resources\n");
+		return;
+	}
+
+	dma_free_coherent(&dummy_dma_dev, 4096, (void *)ioat_desc, 0);
+	iounmap(ioat_iomap);
+}
+
+/* End: I/O AT Helper routines */
+
+#define DIMM_THRTLOW 0x64
+#define DIMM_THRTCTL 0x67
+#define DIMM_THRTCTL_THRMHUNT (1UL << 0)
+#define DIMM_MC 0x40
+#define DIMM_GTW_MODE (1UL << 17)
+#define DIMM_GBLACT 0x60
+
+/*
+ * Keep track of an exponential-decaying average of recent idle durations.
+ * The latest duration gets DURATION_WEIGHT_PCT percentage weight
+ * in this average, with the old average getting the remaining weight.
+ *
+ * High weights emphasize recent history, low weights include long history.
+ */
+#define DURATION_WEIGHT_PCT 55
+
+/*
+ * When the decaying average of recent durations or the predicted duration
+ * of the next timer interrupt is shorter than duration_threshold, the
+ * driver will decline to throttle.
+ */
+#define DURATION_THRESHOLD_US 100
+
+
+/* Store DIMM thermal throttle configuration */
+static int i7300_idle_thrt_save(void)
+{
+	u32 new_mc_val;
+	u8 gblactlm;
+
+	pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &i7300_idle_thrtctl_saved);
+	pci_read_config_byte(fbd_dev, DIMM_THRTLOW, &i7300_idle_thrtlow_saved);
+	pci_read_config_dword(fbd_dev, DIMM_MC, &i7300_idle_mc_saved);
+	/*
+	 * Make sure we have Global Throttling Window Mode set to have a
+	 * "short" window. This (mostly) works around an issue where
+	 * throttling persists until the end of the global throttling window
+	 * size. On the tested system, this was resulting in a maximum of
+	 * 64 ms to exit throttling (average 32 ms). The actual numbers
+	 * depends on system frequencies. Setting the short window reduces
+	 * this by a factor of 4096.
+	 *
+	 * We will only do this only if the system is set for
+	 * unlimited-activations while in open-loop throttling (i.e., when
+	 * Global Activation Throttle Limit is zero).
+	 */
+	pci_read_config_byte(fbd_dev, DIMM_GBLACT, &gblactlm);
+	dprintk("thrtctl_saved = 0x%02x, thrtlow_saved = 0x%02x\n",
+		i7300_idle_thrtctl_saved,
+		i7300_idle_thrtlow_saved);
+	dprintk("mc_saved = 0x%08x, gblactlm = 0x%02x\n",
+		i7300_idle_mc_saved,
+		gblactlm);
+	if (gblactlm == 0) {
+		new_mc_val = i7300_idle_mc_saved | DIMM_GTW_MODE;
+		pci_write_config_dword(fbd_dev, DIMM_MC, new_mc_val);
+		return 0;
+	} else {
+		dprintk("could not set GTW_MODE = 1 (OLTT enabled)\n");
+		return -ENODEV;
+	}
+}
+
+/* Restore DIMM thermal throttle configuration */
+static void i7300_idle_thrt_restore(void)
+{
+	pci_write_config_dword(fbd_dev, DIMM_MC, i7300_idle_mc_saved);
+	pci_write_config_byte(fbd_dev, DIMM_THRTLOW, i7300_idle_thrtlow_saved);
+	pci_write_config_byte(fbd_dev, DIMM_THRTCTL, i7300_idle_thrtctl_saved);
+}
+
+/* Enable DIMM thermal throttling */
+static void i7300_idle_start(void)
+{
+	u8 new_ctl;
+	u8 limit;
+
+	new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT;
+	pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl);
+
+	limit = throttle_low_limit;
+	if (unlikely(limit > MAX_THROTTLE_LOW_LIMIT))
+		limit = MAX_THROTTLE_LOW_LIMIT;
+
+	pci_write_config_byte(fbd_dev, DIMM_THRTLOW, limit);
+
+	new_ctl = i7300_idle_thrtctl_saved | DIMM_THRTCTL_THRMHUNT;
+	pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl);
+}
+
+/* Disable DIMM thermal throttling */
+static void i7300_idle_stop(void)
+{
+	u8 new_ctl;
+	u8 got_ctl;
+
+	new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT;
+	pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl);
+
+	pci_write_config_byte(fbd_dev, DIMM_THRTLOW, i7300_idle_thrtlow_saved);
+	pci_write_config_byte(fbd_dev, DIMM_THRTCTL, i7300_idle_thrtctl_saved);
+	pci_read_config_byte(fbd_dev, DIMM_THRTCTL, &got_ctl);
+	WARN_ON_ONCE(got_ctl != i7300_idle_thrtctl_saved);
+}
+
+
+/*
+ * i7300_avg_duration_check()
+ * return 0 if the decaying average of recent idle durations is
+ * more than DURATION_THRESHOLD_US
+ */
+static int i7300_avg_duration_check(void)
+{
+	if (avg_idle_us >= DURATION_THRESHOLD_US)
+		return 0;
+
+#ifdef DEBUG
+	past_skip++;
+#endif
+	return 1;
+}
+
+/* Idle notifier to look at idle CPUs */
+static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val,
+				void *data)
+{
+	unsigned long flags;
+	ktime_t now_ktime;
+	static ktime_t idle_begin_time;
+	static int time_init = 1;
+
+	if (!throttle_low_limit)
+		return 0;
+
+	if (unlikely(time_init)) {
+		time_init = 0;
+		idle_begin_time = ktime_get();
+	}
+
+	raw_spin_lock_irqsave(&i7300_idle_lock, flags);
+	if (val == IDLE_START) {
+
+		cpumask_set_cpu(smp_processor_id(), idle_cpumask);
+
+		if (cpumask_weight(idle_cpumask) != num_online_cpus())
+			goto end;
+
+		now_ktime = ktime_get();
+		idle_begin_time = now_ktime;
+
+		if (i7300_avg_duration_check())
+			goto end;
+
+		i7300_idle_active = 1;
+		total_starts++;
+		start_ktime = now_ktime;
+
+		i7300_idle_start();
+		i7300_idle_ioat_start();
+
+	} else if (val == IDLE_END) {
+		cpumask_clear_cpu(smp_processor_id(), idle_cpumask);
+		if (cpumask_weight(idle_cpumask) == (num_online_cpus() - 1)) {
+			/* First CPU coming out of idle */
+			u64 idle_duration_us;
+
+			now_ktime = ktime_get();
+
+			idle_duration_us = ktime_to_us(ktime_sub
+						(now_ktime, idle_begin_time));
+
+			avg_idle_us =
+				((100 - DURATION_WEIGHT_PCT) * avg_idle_us +
+				 DURATION_WEIGHT_PCT * idle_duration_us) / 100;
+
+			if (i7300_idle_active) {
+				ktime_t idle_ktime;
+
+				idle_ktime = ktime_sub(now_ktime, start_ktime);
+				total_us += ktime_to_us(idle_ktime);
+
+				i7300_idle_ioat_stop();
+				i7300_idle_stop();
+				i7300_idle_active = 0;
+			}
+		}
+	}
+end:
+	raw_spin_unlock_irqrestore(&i7300_idle_lock, flags);
+	return 0;
+}
+
+static struct notifier_block i7300_idle_nb = {
+	.notifier_call = i7300_idle_notifier,
+};
+
+MODULE_DEVICE_TABLE(pci, pci_tbl);
+
+static ssize_t stats_read_ul(struct file *fp, char __user *ubuf, size_t count,
+				loff_t *off)
+{
+	unsigned long *p = fp->private_data;
+	char buf[32];
+	int len;
+
+	len = snprintf(buf, 32, "%lu\n", *p);
+	return simple_read_from_buffer(ubuf, count, off, buf, len);
+}
+
+static const struct file_operations idle_fops = {
+	.open	= simple_open,
+	.read	= stats_read_ul,
+	.llseek = default_llseek,
+};
+
+struct debugfs_file_info {
+	void *ptr;
+	char name[32];
+	struct dentry *file;
+} debugfs_file_list[] = {
+				{&total_starts, "total_starts", NULL},
+				{&total_us, "total_us", NULL},
+#ifdef DEBUG
+				{&past_skip, "past_skip", NULL},
+#endif
+				{NULL, "", NULL}
+			};
+
+static int __init i7300_idle_init(void)
+{
+	raw_spin_lock_init(&i7300_idle_lock);
+	total_us = 0;
+
+	if (i7300_idle_platform_probe(&fbd_dev, &ioat_dev, forceload))
+		return -ENODEV;
+
+	if (i7300_idle_thrt_save())
+		return -ENODEV;
+
+	if (i7300_idle_ioat_init())
+		return -ENODEV;
+
+	if (!zalloc_cpumask_var(&idle_cpumask, GFP_KERNEL))
+		return -ENOMEM;
+
+	debugfs_dir = debugfs_create_dir("i7300_idle", NULL);
+	if (debugfs_dir) {
+		int i = 0;
+
+		while (debugfs_file_list[i].ptr != NULL) {
+			debugfs_file_list[i].file = debugfs_create_file(
+					debugfs_file_list[i].name,
+					S_IRUSR,
+					debugfs_dir,
+					debugfs_file_list[i].ptr,
+					&idle_fops);
+			i++;
+		}
+	}
+
+	idle_notifier_register(&i7300_idle_nb);
+
+	printk(KERN_INFO "i7300_idle: loaded v%s\n", I7300_IDLE_DRIVER_VERSION);
+	return 0;
+}
+
+static void __exit i7300_idle_exit(void)
+{
+	idle_notifier_unregister(&i7300_idle_nb);
+	free_cpumask_var(idle_cpumask);
+
+	if (debugfs_dir) {
+		int i = 0;
+
+		while (debugfs_file_list[i].file != NULL) {
+			debugfs_remove(debugfs_file_list[i].file);
+			i++;
+		}
+
+		debugfs_remove(debugfs_dir);
+	}
+	i7300_idle_thrt_restore();
+	i7300_idle_ioat_exit();
+}
+
+module_init(i7300_idle_init);
+module_exit(i7300_idle_exit);
+
+MODULE_AUTHOR("Andy Henroid <andrew.d.henroid@intel.com>");
+MODULE_DESCRIPTION("Intel Chipset DIMM Idle Power Saving Driver v"
+			I7300_IDLE_DRIVER_VERSION);
+MODULE_LICENSE("GPL");
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
new file mode 100644
index 000000000..2a36a95d9
--- /dev/null
+++ b/drivers/idle/intel_idle.c
@@ -0,0 +1,1107 @@
+/*
+ * intel_idle.c - native hardware idle loop for modern Intel processors
+ *
+ * Copyright (c) 2013, Intel Corporation.
+ * Len Brown <len.brown@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*
+ * intel_idle is a cpuidle driver that loads on specific Intel processors
+ * in lieu of the legacy ACPI processor_idle driver.  The intent is to
+ * make Linux more efficient on these processors, as intel_idle knows
+ * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
+ */
+
+/*
+ * Design Assumptions
+ *
+ * All CPUs have same idle states as boot CPU
+ *
+ * Chipset BM_STS (bus master status) bit is a NOP
+ *	for preventing entry into deep C-stats
+ */
+
+/*
+ * Known limitations
+ *
+ * The driver currently initializes for_each_online_cpu() upon modprobe.
+ * It it unaware of subsequent processors hot-added to the system.
+ * This means that if you boot with maxcpus=n and later online
+ * processors above n, those processors will use C1 only.
+ *
+ * ACPI has a .suspend hack to turn off deep c-statees during suspend
+ * to avoid complications with the lapic timer workaround.
+ * Have not seen issues with suspend, but may need same workaround here.
+ *
+ * There is currently no kernel-based automatic probing/loading mechanism
+ * if the driver is built as a module.
+ */
+
+/* un-comment DEBUG to enable pr_debug() statements */
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/tick.h>
+#include <trace/events/power.h>
+#include <linux/sched.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+#include <asm/cpu_device_id.h>
+#include <asm/mwait.h>
+#include <asm/msr.h>
+
+#define INTEL_IDLE_VERSION "0.4"
+#define PREFIX "intel_idle: "
+
+static struct cpuidle_driver intel_idle_driver = {
+	.name = "intel_idle",
+	.owner = THIS_MODULE,
+};
+/* intel_idle.max_cstate=0 disables driver */
+static int max_cstate = CPUIDLE_STATE_MAX - 1;
+
+static unsigned int mwait_substates;
+
+#define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
+/* Reliable LAPIC Timer States, bit 1 for C1 etc.  */
+static unsigned int lapic_timer_reliable_states = (1 << 1);	 /* Default to only C1 */
+
+struct idle_cpu {
+	struct cpuidle_state *state_table;
+
+	/*
+	 * Hardware C-state auto-demotion may not always be optimal.
+	 * Indicate which enable bits to clear here.
+	 */
+	unsigned long auto_demotion_disable_flags;
+	bool byt_auto_demotion_disable_flag;
+	bool disable_promotion_to_c1e;
+};
+
+static const struct idle_cpu *icpu;
+static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
+static int intel_idle(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv, int index);
+static void intel_idle_freeze(struct cpuidle_device *dev,
+			      struct cpuidle_driver *drv, int index);
+static int intel_idle_cpu_init(int cpu);
+
+static struct cpuidle_state *cpuidle_state_table;
+
+/*
+ * Set this flag for states where the HW flushes the TLB for us
+ * and so we don't need cross-calls to keep it consistent.
+ * If this flag is set, SW flushes the TLB, so even if the
+ * HW doesn't do the flushing, this flag is safe to use.
+ */
+#define CPUIDLE_FLAG_TLB_FLUSHED	0x10000
+
+/*
+ * MWAIT takes an 8-bit "hint" in EAX "suggesting"
+ * the C-state (top nibble) and sub-state (bottom nibble)
+ * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
+ *
+ * We store the hint at the top of our "flags" for each state.
+ */
+#define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
+#define MWAIT2flg(eax) ((eax & 0xFF) << 24)
+
+/*
+ * States are indexed by the cstate number,
+ * which is also the index into the MWAIT hint array.
+ * Thus C0 is a dummy.
+ */
+static struct cpuidle_state nehalem_cstates[] = {
+	{
+		.name = "C1-NHM",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 3,
+		.target_residency = 6,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-NHM",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 20,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-NHM",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 20,
+		.target_residency = 80,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-NHM",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 200,
+		.target_residency = 800,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state snb_cstates[] = {
+	{
+		.name = "C1-SNB",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 2,
+		.target_residency = 2,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-SNB",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 20,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-SNB",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 80,
+		.target_residency = 211,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-SNB",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 104,
+		.target_residency = 345,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7-SNB",
+		.desc = "MWAIT 0x30",
+		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 109,
+		.target_residency = 345,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state byt_cstates[] = {
+	{
+		.name = "C1-BYT",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6N-BYT",
+		.desc = "MWAIT 0x58",
+		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 300,
+		.target_residency = 275,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6S-BYT",
+		.desc = "MWAIT 0x52",
+		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 500,
+		.target_residency = 560,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7-BYT",
+		.desc = "MWAIT 0x60",
+		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 1200,
+		.target_residency = 4000,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7S-BYT",
+		.desc = "MWAIT 0x64",
+		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 10000,
+		.target_residency = 20000,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state cht_cstates[] = {
+	{
+		.name = "C1-CHT",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6N-CHT",
+		.desc = "MWAIT 0x58",
+		.flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 80,
+		.target_residency = 275,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6S-CHT",
+		.desc = "MWAIT 0x52",
+		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 200,
+		.target_residency = 560,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7-CHT",
+		.desc = "MWAIT 0x60",
+		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 1200,
+		.target_residency = 4000,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7S-CHT",
+		.desc = "MWAIT 0x64",
+		.flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 10000,
+		.target_residency = 20000,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state ivb_cstates[] = {
+	{
+		.name = "C1-IVB",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-IVB",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 20,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-IVB",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 59,
+		.target_residency = 156,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-IVB",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 80,
+		.target_residency = 300,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7-IVB",
+		.desc = "MWAIT 0x30",
+		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 87,
+		.target_residency = 300,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state ivt_cstates[] = {
+	{
+		.name = "C1-IVT",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-IVT",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 80,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-IVT",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 59,
+		.target_residency = 156,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-IVT",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 82,
+		.target_residency = 300,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state ivt_cstates_4s[] = {
+	{
+		.name = "C1-IVT-4S",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-IVT-4S",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 250,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-IVT-4S",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 59,
+		.target_residency = 300,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-IVT-4S",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 84,
+		.target_residency = 400,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state ivt_cstates_8s[] = {
+	{
+		.name = "C1-IVT-8S",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-IVT-8S",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 500,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-IVT-8S",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 59,
+		.target_residency = 600,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-IVT-8S",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 88,
+		.target_residency = 700,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state hsw_cstates[] = {
+	{
+		.name = "C1-HSW",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 2,
+		.target_residency = 2,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-HSW",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 20,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-HSW",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 33,
+		.target_residency = 100,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-HSW",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 133,
+		.target_residency = 400,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7s-HSW",
+		.desc = "MWAIT 0x32",
+		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 166,
+		.target_residency = 500,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C8-HSW",
+		.desc = "MWAIT 0x40",
+		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 300,
+		.target_residency = 900,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C9-HSW",
+		.desc = "MWAIT 0x50",
+		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 600,
+		.target_residency = 1800,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C10-HSW",
+		.desc = "MWAIT 0x60",
+		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 2600,
+		.target_residency = 7700,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+static struct cpuidle_state bdw_cstates[] = {
+	{
+		.name = "C1-BDW",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 2,
+		.target_residency = 2,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C1E-BDW",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01),
+		.exit_latency = 10,
+		.target_residency = 20,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C3-BDW",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 40,
+		.target_residency = 100,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-BDW",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 133,
+		.target_residency = 400,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C7s-BDW",
+		.desc = "MWAIT 0x32",
+		.flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 166,
+		.target_residency = 500,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C8-BDW",
+		.desc = "MWAIT 0x40",
+		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 300,
+		.target_residency = 900,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C9-BDW",
+		.desc = "MWAIT 0x50",
+		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 600,
+		.target_residency = 1800,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C10-BDW",
+		.desc = "MWAIT 0x60",
+		.flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 2600,
+		.target_residency = 7700,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+static struct cpuidle_state atom_cstates[] = {
+	{
+		.name = "C1E-ATM",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 10,
+		.target_residency = 20,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C2-ATM",
+		.desc = "MWAIT 0x10",
+		.flags = MWAIT2flg(0x10),
+		.exit_latency = 20,
+		.target_residency = 80,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C4-ATM",
+		.desc = "MWAIT 0x30",
+		.flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 100,
+		.target_residency = 400,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-ATM",
+		.desc = "MWAIT 0x52",
+		.flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 140,
+		.target_residency = 560,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+static struct cpuidle_state avn_cstates[] = {
+	{
+		.name = "C1-AVN",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 2,
+		.target_residency = 2,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C6-AVN",
+		.desc = "MWAIT 0x51",
+		.flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 15,
+		.target_residency = 45,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
+	{
+		.enter = NULL }
+};
+
+/**
+ * intel_idle
+ * @dev: cpuidle_device
+ * @drv: cpuidle driver
+ * @index: index of cpuidle state
+ *
+ * Must be called under local_irq_disable().
+ */
+static int intel_idle(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int index)
+{
+	unsigned long ecx = 1; /* break on interrupt flag */
+	struct cpuidle_state *state = &drv->states[index];
+	unsigned long eax = flg2MWAIT(state->flags);
+	unsigned int cstate;
+	int cpu = smp_processor_id();
+
+	cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
+
+	/*
+	 * leave_mm() to avoid costly and often unnecessary wakeups
+	 * for flushing the user TLB's associated with the active mm.
+	 */
+	if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
+		leave_mm(cpu);
+
+	if (!(lapic_timer_reliable_states & (1 << (cstate))))
+		tick_broadcast_enter();
+
+	mwait_idle_with_hints(eax, ecx);
+
+	if (!(lapic_timer_reliable_states & (1 << (cstate))))
+		tick_broadcast_exit();
+
+	return index;
+}
+
+/**
+ * intel_idle_freeze - simplified "enter" callback routine for suspend-to-idle
+ * @dev: cpuidle_device
+ * @drv: cpuidle driver
+ * @index: state index
+ */
+static void intel_idle_freeze(struct cpuidle_device *dev,
+			     struct cpuidle_driver *drv, int index)
+{
+	unsigned long ecx = 1; /* break on interrupt flag */
+	unsigned long eax = flg2MWAIT(drv->states[index].flags);
+
+	mwait_idle_with_hints(eax, ecx);
+}
+
+static void __setup_broadcast_timer(void *arg)
+{
+	unsigned long on = (unsigned long)arg;
+
+	if (on)
+		tick_broadcast_enable();
+	else
+		tick_broadcast_disable();
+}
+
+static int cpu_hotplug_notify(struct notifier_block *n,
+			      unsigned long action, void *hcpu)
+{
+	int hotcpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev;
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_ONLINE:
+
+		if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
+			smp_call_function_single(hotcpu, __setup_broadcast_timer,
+						 (void *)true, 1);
+
+		/*
+		 * Some systems can hotplug a cpu at runtime after
+		 * the kernel has booted, we have to initialize the
+		 * driver in this case
+		 */
+		dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
+		if (!dev->registered)
+			intel_idle_cpu_init(hotcpu);
+
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpu_hotplug_notifier = {
+	.notifier_call = cpu_hotplug_notify,
+};
+
+static void auto_demotion_disable(void *dummy)
+{
+	unsigned long long msr_bits;
+
+	rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
+	msr_bits &= ~(icpu->auto_demotion_disable_flags);
+	wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
+}
+static void c1e_promotion_disable(void *dummy)
+{
+	unsigned long long msr_bits;
+
+	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
+	msr_bits &= ~0x2;
+	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
+}
+
+static const struct idle_cpu idle_cpu_nehalem = {
+	.state_table = nehalem_cstates,
+	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
+	.disable_promotion_to_c1e = true,
+};
+
+static const struct idle_cpu idle_cpu_atom = {
+	.state_table = atom_cstates,
+};
+
+static const struct idle_cpu idle_cpu_lincroft = {
+	.state_table = atom_cstates,
+	.auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
+};
+
+static const struct idle_cpu idle_cpu_snb = {
+	.state_table = snb_cstates,
+	.disable_promotion_to_c1e = true,
+};
+
+static const struct idle_cpu idle_cpu_byt = {
+	.state_table = byt_cstates,
+	.disable_promotion_to_c1e = true,
+	.byt_auto_demotion_disable_flag = true,
+};
+
+static const struct idle_cpu idle_cpu_cht = {
+	.state_table = cht_cstates,
+	.disable_promotion_to_c1e = true,
+	.byt_auto_demotion_disable_flag = true,
+};
+
+static const struct idle_cpu idle_cpu_ivb = {
+	.state_table = ivb_cstates,
+	.disable_promotion_to_c1e = true,
+};
+
+static const struct idle_cpu idle_cpu_ivt = {
+	.state_table = ivt_cstates,
+	.disable_promotion_to_c1e = true,
+};
+
+static const struct idle_cpu idle_cpu_hsw = {
+	.state_table = hsw_cstates,
+	.disable_promotion_to_c1e = true,
+};
+
+static const struct idle_cpu idle_cpu_bdw = {
+	.state_table = bdw_cstates,
+	.disable_promotion_to_c1e = true,
+};
+
+static const struct idle_cpu idle_cpu_avn = {
+	.state_table = avn_cstates,
+	.disable_promotion_to_c1e = true,
+};
+
+#define ICPU(model, cpu) \
+	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
+
+static const struct x86_cpu_id intel_idle_ids[] __initconst = {
+	ICPU(0x1a, idle_cpu_nehalem),
+	ICPU(0x1e, idle_cpu_nehalem),
+	ICPU(0x1f, idle_cpu_nehalem),
+	ICPU(0x25, idle_cpu_nehalem),
+	ICPU(0x2c, idle_cpu_nehalem),
+	ICPU(0x2e, idle_cpu_nehalem),
+	ICPU(0x1c, idle_cpu_atom),
+	ICPU(0x26, idle_cpu_lincroft),
+	ICPU(0x2f, idle_cpu_nehalem),
+	ICPU(0x2a, idle_cpu_snb),
+	ICPU(0x2d, idle_cpu_snb),
+	ICPU(0x36, idle_cpu_atom),
+	ICPU(0x37, idle_cpu_byt),
+	ICPU(0x4c, idle_cpu_cht),
+	ICPU(0x3a, idle_cpu_ivb),
+	ICPU(0x3e, idle_cpu_ivt),
+	ICPU(0x3c, idle_cpu_hsw),
+	ICPU(0x3f, idle_cpu_hsw),
+	ICPU(0x45, idle_cpu_hsw),
+	ICPU(0x46, idle_cpu_hsw),
+	ICPU(0x4d, idle_cpu_avn),
+	ICPU(0x3d, idle_cpu_bdw),
+	ICPU(0x47, idle_cpu_bdw),
+	ICPU(0x4f, idle_cpu_bdw),
+	ICPU(0x56, idle_cpu_bdw),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
+
+/*
+ * intel_idle_probe()
+ */
+static int __init intel_idle_probe(void)
+{
+	unsigned int eax, ebx, ecx;
+	const struct x86_cpu_id *id;
+
+	if (max_cstate == 0) {
+		pr_debug(PREFIX "disabled\n");
+		return -EPERM;
+	}
+
+	id = x86_match_cpu(intel_idle_ids);
+	if (!id) {
+		if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+		    boot_cpu_data.x86 == 6)
+			pr_debug(PREFIX "does not run on family %d model %d\n",
+				boot_cpu_data.x86, boot_cpu_data.x86_model);
+		return -ENODEV;
+	}
+
+	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
+		return -ENODEV;
+
+	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
+
+	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
+	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
+	    !mwait_substates)
+			return -ENODEV;
+
+	pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
+
+	icpu = (const struct idle_cpu *)id->driver_data;
+	cpuidle_state_table = icpu->state_table;
+
+	if (boot_cpu_has(X86_FEATURE_ARAT))	/* Always Reliable APIC Timer */
+		lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
+	else
+		on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
+
+	pr_debug(PREFIX "v" INTEL_IDLE_VERSION
+		" model 0x%X\n", boot_cpu_data.x86_model);
+
+	pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
+		lapic_timer_reliable_states);
+	return 0;
+}
+
+/*
+ * intel_idle_cpuidle_devices_uninit()
+ * unregister, free cpuidle_devices
+ */
+static void intel_idle_cpuidle_devices_uninit(void)
+{
+	int i;
+	struct cpuidle_device *dev;
+
+	for_each_online_cpu(i) {
+		dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
+		cpuidle_unregister_device(dev);
+	}
+
+	free_percpu(intel_idle_cpuidle_devices);
+	return;
+}
+
+/*
+ * intel_idle_state_table_update()
+ *
+ * Update the default state_table for this CPU-id
+ *
+ * Currently used to access tuned IVT multi-socket targets
+ * Assumption: num_sockets == (max_package_num + 1)
+ */
+void intel_idle_state_table_update(void)
+{
+	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
+	if (boot_cpu_data.x86_model == 0x3e) { /* IVT */
+		int cpu, package_num, num_sockets = 1;
+
+		for_each_online_cpu(cpu) {
+			package_num = topology_physical_package_id(cpu);
+			if (package_num + 1 > num_sockets) {
+				num_sockets = package_num + 1;
+
+				if (num_sockets > 4) {
+					cpuidle_state_table = ivt_cstates_8s;
+					return;
+				}
+			}
+		}
+
+		if (num_sockets > 2)
+			cpuidle_state_table = ivt_cstates_4s;
+		/* else, 1 and 2 socket systems use default ivt_cstates */
+	}
+	return;
+}
+
+/*
+ * intel_idle_cpuidle_driver_init()
+ * allocate, initialize cpuidle_states
+ */
+static int __init intel_idle_cpuidle_driver_init(void)
+{
+	int cstate;
+	struct cpuidle_driver *drv = &intel_idle_driver;
+
+	intel_idle_state_table_update();
+
+	drv->state_count = 1;
+
+	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
+		int num_substates, mwait_hint, mwait_cstate;
+
+		if (cpuidle_state_table[cstate].enter == NULL)
+			break;
+
+		if (cstate + 1 > max_cstate) {
+			printk(PREFIX "max_cstate %d reached\n",
+				max_cstate);
+			break;
+		}
+
+		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
+		mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
+
+		/* number of sub-states for this state in CPUID.MWAIT */
+		num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
+					& MWAIT_SUBSTATE_MASK;
+
+		/* if NO sub-states for this state in CPUID, skip it */
+		if (num_substates == 0)
+			continue;
+
+		if (((mwait_cstate + 1) > 2) &&
+			!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+			mark_tsc_unstable("TSC halts in idle"
+					" states deeper than C2");
+
+		drv->states[drv->state_count] =	/* structure copy */
+			cpuidle_state_table[cstate];
+
+		drv->state_count += 1;
+	}
+
+	if (icpu->auto_demotion_disable_flags)
+		on_each_cpu(auto_demotion_disable, NULL, 1);
+
+	if (icpu->byt_auto_demotion_disable_flag) {
+		wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
+		wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
+	}
+
+	if (icpu->disable_promotion_to_c1e)	/* each-cpu is redundant */
+		on_each_cpu(c1e_promotion_disable, NULL, 1);
+
+	return 0;
+}
+
+
+/*
+ * intel_idle_cpu_init()
+ * allocate, initialize, register cpuidle_devices
+ * @cpu: cpu/core to initialize
+ */
+static int intel_idle_cpu_init(int cpu)
+{
+	struct cpuidle_device *dev;
+
+	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
+
+	dev->cpu = cpu;
+
+	if (cpuidle_register_device(dev)) {
+		pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
+		intel_idle_cpuidle_devices_uninit();
+		return -EIO;
+	}
+
+	if (icpu->auto_demotion_disable_flags)
+		smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
+
+	if (icpu->disable_promotion_to_c1e)
+		smp_call_function_single(cpu, c1e_promotion_disable, NULL, 1);
+
+	return 0;
+}
+
+static int __init intel_idle_init(void)
+{
+	int retval, i;
+
+	/* Do not load intel_idle at all for now if idle= is passed */
+	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
+		return -ENODEV;
+
+	retval = intel_idle_probe();
+	if (retval)
+		return retval;
+
+	intel_idle_cpuidle_driver_init();
+	retval = cpuidle_register_driver(&intel_idle_driver);
+	if (retval) {
+		struct cpuidle_driver *drv = cpuidle_get_driver();
+		printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
+			drv ? drv->name : "none");
+		return retval;
+	}
+
+	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+	if (intel_idle_cpuidle_devices == NULL)
+		return -ENOMEM;
+
+	cpu_notifier_register_begin();
+
+	for_each_online_cpu(i) {
+		retval = intel_idle_cpu_init(i);
+		if (retval) {
+			cpu_notifier_register_done();
+			cpuidle_unregister_driver(&intel_idle_driver);
+			return retval;
+		}
+	}
+	__register_cpu_notifier(&cpu_hotplug_notifier);
+
+	cpu_notifier_register_done();
+
+	return 0;
+}
+
+static void __exit intel_idle_exit(void)
+{
+	intel_idle_cpuidle_devices_uninit();
+	cpuidle_unregister_driver(&intel_idle_driver);
+
+	cpu_notifier_register_begin();
+
+	if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
+		on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
+	__unregister_cpu_notifier(&cpu_hotplug_notifier);
+
+	cpu_notifier_register_done();
+
+	return;
+}
+
+module_init(intel_idle_init);
+module_exit(intel_idle_exit);
+
+module_param(max_cstate, int, 0444);
+
+MODULE_AUTHOR("Len Brown <len.brown@intel.com>");
+MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION);
+MODULE_LICENSE("GPL");