Merge branch 'x86/platform' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into stable/for-linus-3.7

* 'x86/platform' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (9690 commits)
  x86: Document x86_init.paging.pagetable_init()
  x86: xen: Cleanup and remove x86_init.paging.pagetable_setup_done()
  x86: Move paging_init() call to x86_init.paging.pagetable_init()
  x86: Rename pagetable_setup_start() to pagetable_init()
  x86: Remove base argument from x86_init.paging.pagetable_setup_start
  Linux 3.6-rc5
  HID: tpkbd: work even if the new Lenovo Keyboard driver is not configured
  Remove user-triggerable BUG from mpol_to_str
  xen/pciback: Fix proper FLR steps.
  uml: fix compile error in deliver_alarm()
  dj: memory scribble in logi_dj
  Fix order of arguments to compat_put_time[spec|val]
  xen: Use correct masking in xen_swiotlb_alloc_coherent.
  xen: fix logical error in tlb flushing
  xen/p2m: Fix one-off error in checking the P2M tree directory.
  powerpc: Don't use __put_user() in patch_instruction
  powerpc: Make sure IPI handlers see data written by IPI senders
  powerpc: Restore correct DSCR in context switch
  powerpc: Fix DSCR inheritance in copy_thread()
  powerpc: Keep thread.dscr and thread.dscr_inherit in sync
  ...

drivers/xen/Kconfig

@@ -196,4 +196,12 @@ config XEN_ACPI_PROCESSOR
 	  called xen_acpi_processor  If you do not know what to choose, select
 	  M here. If the CPUFREQ drivers are built in, select Y here.
 
+config XEN_MCE_LOG
+	bool "Xen platform mcelog"
+	depends on XEN_DOM0 && X86_64 && X86_MCE
+	default n
+	help
+	  Allow kernel fetching MCE error from Xen platform and
+	  converting it into Linux mcelog format for mcelog tools
+
 endmenu

drivers/xen/Makefile

@@ -17,7 +17,9 @@ obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
 obj-$(CONFIG_XEN_PVHVM)			+= platform-pci.o
 obj-$(CONFIG_XEN_TMEM)			+= tmem.o
 obj-$(CONFIG_SWIOTLB_XEN)		+= swiotlb-xen.o
+obj-$(CONFIG_XEN_DOM0)			+= pcpu.o
 obj-$(CONFIG_XEN_DOM0)			+= pci.o acpi.o
+obj-$(CONFIG_XEN_MCE_LOG)		+= mcelog.o
 obj-$(CONFIG_XEN_PCIDEV_BACKEND)	+= xen-pciback/
 obj-$(CONFIG_XEN_PRIVCMD)		+= xen-privcmd.o
 obj-$(CONFIG_XEN_ACPI_PROCESSOR)	+= xen-acpi-processor.o

drivers/xen/mcelog.c

@@ -0,0 +1,414 @@
+/******************************************************************************
+ * mcelog.c
+ * Driver for receiving and transferring machine check error infomation
+ *
+ * Copyright (c) 2012 Intel Corporation
+ * Author: Liu, Jinsong <jinsong.liu@intel.com>
+ * Author: Jiang, Yunhong <yunhong.jiang@intel.com>
+ * Author: Ke, Liping <liping.ke@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/uaccess.h>
+#include <linux/capability.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+
+#include <xen/interface/xen.h>
+#include <xen/events.h>
+#include <xen/interface/vcpu.h>
+#include <xen/xen.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/hypervisor.h>
+
+#define XEN_MCELOG "xen_mcelog: "
+
+static struct mc_info g_mi;
+static struct mcinfo_logical_cpu *g_physinfo;
+static uint32_t ncpus;
+
+static DEFINE_MUTEX(mcelog_lock);
+
+static struct xen_mce_log xen_mcelog = {
+	.signature	= XEN_MCE_LOG_SIGNATURE,
+	.len		= XEN_MCE_LOG_LEN,
+	.recordlen	= sizeof(struct xen_mce),
+};
+
+static DEFINE_SPINLOCK(xen_mce_chrdev_state_lock);
+static int xen_mce_chrdev_open_count;	/* #times opened */
+static int xen_mce_chrdev_open_exclu;	/* already open exclusive? */
+
+static DECLARE_WAIT_QUEUE_HEAD(xen_mce_chrdev_wait);
+
+static int xen_mce_chrdev_open(struct inode *inode, struct file *file)
+{
+	spin_lock(&xen_mce_chrdev_state_lock);
+
+	if (xen_mce_chrdev_open_exclu ||
+	    (xen_mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
+		spin_unlock(&xen_mce_chrdev_state_lock);
+
+		return -EBUSY;
+	}
+
+	if (file->f_flags & O_EXCL)
+		xen_mce_chrdev_open_exclu = 1;
+	xen_mce_chrdev_open_count++;
+
+	spin_unlock(&xen_mce_chrdev_state_lock);
+
+	return nonseekable_open(inode, file);
+}
+
+static int xen_mce_chrdev_release(struct inode *inode, struct file *file)
+{
+	spin_lock(&xen_mce_chrdev_state_lock);
+
+	xen_mce_chrdev_open_count--;
+	xen_mce_chrdev_open_exclu = 0;
+
+	spin_unlock(&xen_mce_chrdev_state_lock);
+
+	return 0;
+}
+
+static ssize_t xen_mce_chrdev_read(struct file *filp, char __user *ubuf,
+				size_t usize, loff_t *off)
+{
+	char __user *buf = ubuf;
+	unsigned num;
+	int i, err;
+
+	mutex_lock(&mcelog_lock);
+
+	num = xen_mcelog.next;
+
+	/* Only supports full reads right now */
+	err = -EINVAL;
+	if (*off != 0 || usize < XEN_MCE_LOG_LEN*sizeof(struct xen_mce))
+		goto out;
+
+	err = 0;
+	for (i = 0; i < num; i++) {
+		struct xen_mce *m = &xen_mcelog.entry[i];
+
+		err |= copy_to_user(buf, m, sizeof(*m));
+		buf += sizeof(*m);
+	}
+
+	memset(xen_mcelog.entry, 0, num * sizeof(struct xen_mce));
+	xen_mcelog.next = 0;
+
+	if (err)
+		err = -EFAULT;
+
+out:
+	mutex_unlock(&mcelog_lock);
+
+	return err ? err : buf - ubuf;
+}
+
+static unsigned int xen_mce_chrdev_poll(struct file *file, poll_table *wait)
+{
+	poll_wait(file, &xen_mce_chrdev_wait, wait);
+
+	if (xen_mcelog.next)
+		return POLLIN | POLLRDNORM;
+
+	return 0;
+}
+
+static long xen_mce_chrdev_ioctl(struct file *f, unsigned int cmd,
+				unsigned long arg)
+{
+	int __user *p = (int __user *)arg;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case MCE_GET_RECORD_LEN:
+		return put_user(sizeof(struct xen_mce), p);
+	case MCE_GET_LOG_LEN:
+		return put_user(XEN_MCE_LOG_LEN, p);
+	case MCE_GETCLEAR_FLAGS: {
+		unsigned flags;
+
+		do {
+			flags = xen_mcelog.flags;
+		} while (cmpxchg(&xen_mcelog.flags, flags, 0) != flags);
+
+		return put_user(flags, p);
+	}
+	default:
+		return -ENOTTY;
+	}
+}
+
+static const struct file_operations xen_mce_chrdev_ops = {
+	.open			= xen_mce_chrdev_open,
+	.release		= xen_mce_chrdev_release,
+	.read			= xen_mce_chrdev_read,
+	.poll			= xen_mce_chrdev_poll,
+	.unlocked_ioctl		= xen_mce_chrdev_ioctl,
+	.llseek			= no_llseek,
+};
+
+static struct miscdevice xen_mce_chrdev_device = {
+	MISC_MCELOG_MINOR,
+	"mcelog",
+	&xen_mce_chrdev_ops,
+};
+
+/*
+ * Caller should hold the mcelog_lock
+ */
+static void xen_mce_log(struct xen_mce *mce)
+{
+	unsigned entry;
+
+	entry = xen_mcelog.next;
+
+	/*
+	 * When the buffer fills up discard new entries.
+	 * Assume that the earlier errors are the more
+	 * interesting ones:
+	 */
+	if (entry >= XEN_MCE_LOG_LEN) {
+		set_bit(XEN_MCE_OVERFLOW,
+			(unsigned long *)&xen_mcelog.flags);
+		return;
+	}
+
+	memcpy(xen_mcelog.entry + entry, mce, sizeof(struct xen_mce));
+
+	xen_mcelog.next++;
+}
+
+static int convert_log(struct mc_info *mi)
+{
+	struct mcinfo_common *mic;
+	struct mcinfo_global *mc_global;
+	struct mcinfo_bank *mc_bank;
+	struct xen_mce m;
+	uint32_t i;
+
+	mic = NULL;
+	x86_mcinfo_lookup(&mic, mi, MC_TYPE_GLOBAL);
+	if (unlikely(!mic)) {
+		pr_warning(XEN_MCELOG "Failed to find global error info\n");
+		return -ENODEV;
+	}
+
+	memset(&m, 0, sizeof(struct xen_mce));
+
+	mc_global = (struct mcinfo_global *)mic;
+	m.mcgstatus = mc_global->mc_gstatus;
+	m.apicid = mc_global->mc_apicid;
+
+	for (i = 0; i < ncpus; i++)
+		if (g_physinfo[i].mc_apicid == m.apicid)
+			break;
+	if (unlikely(i == ncpus)) {
+		pr_warning(XEN_MCELOG "Failed to match cpu with apicid %d\n",
+			   m.apicid);
+		return -ENODEV;
+	}
+
+	m.socketid = g_physinfo[i].mc_chipid;
+	m.cpu = m.extcpu = g_physinfo[i].mc_cpunr;
+	m.cpuvendor = (__u8)g_physinfo[i].mc_vendor;
+	m.mcgcap = g_physinfo[i].mc_msrvalues[__MC_MSR_MCGCAP].value;
+
+	mic = NULL;
+	x86_mcinfo_lookup(&mic, mi, MC_TYPE_BANK);
+	if (unlikely(!mic)) {
+		pr_warning(XEN_MCELOG "Fail to find bank error info\n");
+		return -ENODEV;
+	}
+
+	do {
+		if ((!mic) || (mic->size == 0) ||
+		    (mic->type != MC_TYPE_GLOBAL   &&
+		     mic->type != MC_TYPE_BANK     &&
+		     mic->type != MC_TYPE_EXTENDED &&
+		     mic->type != MC_TYPE_RECOVERY))
+			break;
+
+		if (mic->type == MC_TYPE_BANK) {
+			mc_bank = (struct mcinfo_bank *)mic;
+			m.misc = mc_bank->mc_misc;
+			m.status = mc_bank->mc_status;
+			m.addr = mc_bank->mc_addr;
+			m.tsc = mc_bank->mc_tsc;
+			m.bank = mc_bank->mc_bank;
+			m.finished = 1;
+			/*log this record*/
+			xen_mce_log(&m);
+		}
+		mic = x86_mcinfo_next(mic);
+	} while (1);
+
+	return 0;
+}
+
+static int mc_queue_handle(uint32_t flags)
+{
+	struct xen_mc mc_op;
+	int ret = 0;
+
+	mc_op.cmd = XEN_MC_fetch;
+	mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
+	set_xen_guest_handle(mc_op.u.mc_fetch.data, &g_mi);
+	do {
+		mc_op.u.mc_fetch.flags = flags;
+		ret = HYPERVISOR_mca(&mc_op);
+		if (ret) {
+			pr_err(XEN_MCELOG "Failed to fetch %s error log\n",
+			       (flags == XEN_MC_URGENT) ?
+			       "urgnet" : "nonurgent");
+			break;
+		}
+
+		if (mc_op.u.mc_fetch.flags & XEN_MC_NODATA ||
+		    mc_op.u.mc_fetch.flags & XEN_MC_FETCHFAILED)
+			break;
+		else {
+			ret = convert_log(&g_mi);
+			if (ret)
+				pr_warning(XEN_MCELOG
+					   "Failed to convert this error log, "
+					   "continue acking it anyway\n");
+
+			mc_op.u.mc_fetch.flags = flags | XEN_MC_ACK;
+			ret = HYPERVISOR_mca(&mc_op);
+			if (ret) {
+				pr_err(XEN_MCELOG
+				       "Failed to ack previous error log\n");
+				break;
+			}
+		}
+	} while (1);
+
+	return ret;
+}
+
+/* virq handler for machine check error info*/
+static void xen_mce_work_fn(struct work_struct *work)
+{
+	int err;
+
+	mutex_lock(&mcelog_lock);
+
+	/* urgent mc_info */
+	err = mc_queue_handle(XEN_MC_URGENT);
+	if (err)
+		pr_err(XEN_MCELOG
+		       "Failed to handle urgent mc_info queue, "
+		       "continue handling nonurgent mc_info queue anyway.\n");
+
+	/* nonurgent mc_info */
+	err = mc_queue_handle(XEN_MC_NONURGENT);
+	if (err)
+		pr_err(XEN_MCELOG
+		       "Failed to handle nonurgent mc_info queue.\n");
+
+	/* wake processes polling /dev/mcelog */
+	wake_up_interruptible(&xen_mce_chrdev_wait);
+
+	mutex_unlock(&mcelog_lock);
+}
+static DECLARE_WORK(xen_mce_work, xen_mce_work_fn);
+
+static irqreturn_t xen_mce_interrupt(int irq, void *dev_id)
+{
+	schedule_work(&xen_mce_work);
+	return IRQ_HANDLED;
+}
+
+static int bind_virq_for_mce(void)
+{
+	int ret;
+	struct xen_mc mc_op;
+
+	memset(&mc_op, 0, sizeof(struct xen_mc));
+
+	/* Fetch physical CPU Numbers */
+	mc_op.cmd = XEN_MC_physcpuinfo;
+	mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
+	set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
+	ret = HYPERVISOR_mca(&mc_op);
+	if (ret) {
+		pr_err(XEN_MCELOG "Failed to get CPU numbers\n");
+		return ret;
+	}
+
+	/* Fetch each CPU Physical Info for later reference*/
+	ncpus = mc_op.u.mc_physcpuinfo.ncpus;
+	g_physinfo = kcalloc(ncpus, sizeof(struct mcinfo_logical_cpu),
+			     GFP_KERNEL);
+	if (!g_physinfo)
+		return -ENOMEM;
+	set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
+	ret = HYPERVISOR_mca(&mc_op);
+	if (ret) {
+		pr_err(XEN_MCELOG "Failed to get CPU info\n");
+		kfree(g_physinfo);
+		return ret;
+	}
+
+	ret  = bind_virq_to_irqhandler(VIRQ_MCA, 0,
+				       xen_mce_interrupt, 0, "mce", NULL);
+	if (ret < 0) {
+		pr_err(XEN_MCELOG "Failed to bind virq\n");
+		kfree(g_physinfo);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __init xen_late_init_mcelog(void)
+{
+	/* Only DOM0 is responsible for MCE logging */
+	if (xen_initial_domain()) {
+		/* register character device /dev/mcelog for xen mcelog */
+		if (misc_register(&xen_mce_chrdev_device))
+			return -ENODEV;
+		return bind_virq_for_mce();
+	}
+
+	return -ENODEV;
+}
+device_initcall(xen_late_init_mcelog);

drivers/xen/pcpu.c

@@ -0,0 +1,371 @@
+/******************************************************************************
+ * pcpu.c
+ * Management physical cpu in dom0, get pcpu info and provide sys interface
+ *
+ * Copyright (c) 2012 Intel Corporation
+ * Author: Liu, Jinsong <jinsong.liu@intel.com>
+ * Author: Jiang, Yunhong <yunhong.jiang@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/cpu.h>
+#include <linux/stat.h>
+#include <linux/capability.h>
+
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+#include <xen/events.h>
+#include <xen/interface/platform.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+#define XEN_PCPU "xen_cpu: "
+
+/*
+ * @cpu_id: Xen physical cpu logic number
+ * @flags: Xen physical cpu status flag
+ * - XEN_PCPU_FLAGS_ONLINE: cpu is online
+ * - XEN_PCPU_FLAGS_INVALID: cpu is not present
+ */
+struct pcpu {
+	struct list_head list;
+	struct device dev;
+	uint32_t cpu_id;
+	uint32_t flags;
+};
+
+static struct bus_type xen_pcpu_subsys = {
+	.name = "xen_cpu",
+	.dev_name = "xen_cpu",
+};
+
+static DEFINE_MUTEX(xen_pcpu_lock);
+
+static LIST_HEAD(xen_pcpus);
+
+static int xen_pcpu_down(uint32_t cpu_id)
+{
+	struct xen_platform_op op = {
+		.cmd			= XENPF_cpu_offline,
+		.interface_version	= XENPF_INTERFACE_VERSION,
+		.u.cpu_ol.cpuid		= cpu_id,
+	};
+
+	return HYPERVISOR_dom0_op(&op);
+}
+
+static int xen_pcpu_up(uint32_t cpu_id)
+{
+	struct xen_platform_op op = {
+		.cmd			= XENPF_cpu_online,
+		.interface_version	= XENPF_INTERFACE_VERSION,
+		.u.cpu_ol.cpuid		= cpu_id,
+	};
+
+	return HYPERVISOR_dom0_op(&op);
+}
+
+static ssize_t show_online(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	struct pcpu *cpu = container_of(dev, struct pcpu, dev);
+
+	return sprintf(buf, "%u\n", !!(cpu->flags & XEN_PCPU_FLAGS_ONLINE));
+}
+
+static ssize_t __ref store_online(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct pcpu *pcpu = container_of(dev, struct pcpu, dev);
+	unsigned long long val;
+	ssize_t ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (kstrtoull(buf, 0, &val) < 0)
+		return -EINVAL;
+
+	switch (val) {
+	case 0:
+		ret = xen_pcpu_down(pcpu->cpu_id);
+		break;
+	case 1:
+		ret = xen_pcpu_up(pcpu->cpu_id);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret >= 0)
+		ret = count;
+	return ret;
+}
+static DEVICE_ATTR(online, S_IRUGO | S_IWUSR, show_online, store_online);
+
+static bool xen_pcpu_online(uint32_t flags)
+{
+	return !!(flags & XEN_PCPU_FLAGS_ONLINE);
+}
+
+static void pcpu_online_status(struct xenpf_pcpuinfo *info,
+			       struct pcpu *pcpu)
+{
+	if (xen_pcpu_online(info->flags) &&
+	   !xen_pcpu_online(pcpu->flags)) {
+		/* the pcpu is onlined */
+		pcpu->flags |= XEN_PCPU_FLAGS_ONLINE;
+		kobject_uevent(&pcpu->dev.kobj, KOBJ_ONLINE);
+	} else if (!xen_pcpu_online(info->flags) &&
+		    xen_pcpu_online(pcpu->flags)) {
+		/* The pcpu is offlined */
+		pcpu->flags &= ~XEN_PCPU_FLAGS_ONLINE;
+		kobject_uevent(&pcpu->dev.kobj, KOBJ_OFFLINE);
+	}
+}
+
+static struct pcpu *get_pcpu(uint32_t cpu_id)
+{
+	struct pcpu *pcpu;
+
+	list_for_each_entry(pcpu, &xen_pcpus, list) {
+		if (pcpu->cpu_id == cpu_id)
+			return pcpu;
+	}
+
+	return NULL;
+}
+
+static void pcpu_release(struct device *dev)
+{
+	struct pcpu *pcpu = container_of(dev, struct pcpu, dev);
+
+	list_del(&pcpu->list);
+	kfree(pcpu);
+}
+
+static void unregister_and_remove_pcpu(struct pcpu *pcpu)
+{
+	struct device *dev;
+
+	if (!pcpu)
+		return;
+
+	dev = &pcpu->dev;
+	if (dev->id)
+		device_remove_file(dev, &dev_attr_online);
+
+	/* pcpu remove would be implicitly done */
+	device_unregister(dev);
+}
+
+static int register_pcpu(struct pcpu *pcpu)
+{
+	struct device *dev;
+	int err = -EINVAL;
+
+	if (!pcpu)
+		return err;
+
+	dev = &pcpu->dev;
+	dev->bus = &xen_pcpu_subsys;
+	dev->id = pcpu->cpu_id;
+	dev->release = pcpu_release;
+
+	err = device_register(dev);
+	if (err) {
+		pcpu_release(dev);
+		return err;
+	}
+
+	/*
+	 * Xen never offline cpu0 due to several restrictions
+	 * and assumptions. This basically doesn't add a sys control
+	 * to user, one cannot attempt to offline BSP.
+	 */
+	if (dev->id) {
+		err = device_create_file(dev, &dev_attr_online);
+		if (err) {
+			device_unregister(dev);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static struct pcpu *create_and_register_pcpu(struct xenpf_pcpuinfo *info)
+{
+	struct pcpu *pcpu;
+	int err;
+
+	if (info->flags & XEN_PCPU_FLAGS_INVALID)
+		return ERR_PTR(-ENODEV);
+
+	pcpu = kzalloc(sizeof(struct pcpu), GFP_KERNEL);
+	if (!pcpu)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&pcpu->list);
+	pcpu->cpu_id = info->xen_cpuid;
+	pcpu->flags = info->flags;
+
+	/* Need hold on xen_pcpu_lock before pcpu list manipulations */
+	list_add_tail(&pcpu->list, &xen_pcpus);
+
+	err = register_pcpu(pcpu);
+	if (err) {
+		pr_warning(XEN_PCPU "Failed to register pcpu%u\n",
+			   info->xen_cpuid);
+		return ERR_PTR(-ENOENT);
+	}
+
+	return pcpu;
+}
+
+/*
+ * Caller should hold the xen_pcpu_lock
+ */
+static int sync_pcpu(uint32_t cpu, uint32_t *max_cpu)
+{
+	int ret;
+	struct pcpu *pcpu = NULL;
+	struct xenpf_pcpuinfo *info;
+	struct xen_platform_op op = {
+		.cmd                   = XENPF_get_cpuinfo,
+		.interface_version     = XENPF_INTERFACE_VERSION,
+		.u.pcpu_info.xen_cpuid = cpu,
+	};
+
+	ret = HYPERVISOR_dom0_op(&op);
+	if (ret)
+		return ret;
+
+	info = &op.u.pcpu_info;
+	if (max_cpu)
+		*max_cpu = info->max_present;
+
+	pcpu = get_pcpu(cpu);
+
+	/*
+	 * Only those at cpu present map has its sys interface.
+	 */
+	if (info->flags & XEN_PCPU_FLAGS_INVALID) {
+		if (pcpu)
+			unregister_and_remove_pcpu(pcpu);
+		return 0;
+	}
+
+	if (!pcpu) {
+		pcpu = create_and_register_pcpu(info);
+		if (IS_ERR_OR_NULL(pcpu))
+			return -ENODEV;
+	} else
+		pcpu_online_status(info, pcpu);
+
+	return 0;
+}
+
+/*
+ * Sync dom0's pcpu information with xen hypervisor's
+ */
+static int xen_sync_pcpus(void)
+{
+	/*
+	 * Boot cpu always have cpu_id 0 in xen
+	 */
+	uint32_t cpu = 0, max_cpu = 0;
+	int err = 0;
+	struct pcpu *pcpu, *tmp;
+
+	mutex_lock(&xen_pcpu_lock);
+
+	while (!err && (cpu <= max_cpu)) {
+		err = sync_pcpu(cpu, &max_cpu);
+		cpu++;
+	}
+
+	if (err)
+		list_for_each_entry_safe(pcpu, tmp, &xen_pcpus, list)
+			unregister_and_remove_pcpu(pcpu);
+
+	mutex_unlock(&xen_pcpu_lock);
+
+	return err;
+}
+
+static void xen_pcpu_work_fn(struct work_struct *work)
+{
+	xen_sync_pcpus();
+}
+static DECLARE_WORK(xen_pcpu_work, xen_pcpu_work_fn);
+
+static irqreturn_t xen_pcpu_interrupt(int irq, void *dev_id)
+{
+	schedule_work(&xen_pcpu_work);
+	return IRQ_HANDLED;
+}
+
+static int __init xen_pcpu_init(void)
+{
+	int irq, ret;
+
+	if (!xen_initial_domain())
+		return -ENODEV;
+
+	irq = bind_virq_to_irqhandler(VIRQ_PCPU_STATE, 0,
+				      xen_pcpu_interrupt, 0,
+				      "xen-pcpu", NULL);
+	if (irq < 0) {
+		pr_warning(XEN_PCPU "Failed to bind pcpu virq\n");
+		return irq;
+	}
+
+	ret = subsys_system_register(&xen_pcpu_subsys, NULL);
+	if (ret) {
+		pr_warning(XEN_PCPU "Failed to register pcpu subsys\n");
+		goto err1;
+	}
+
+	ret = xen_sync_pcpus();
+	if (ret) {
+		pr_warning(XEN_PCPU "Failed to sync pcpu info\n");
+		goto err2;
+	}
+
+	return 0;
+
+err2:
+	bus_unregister(&xen_pcpu_subsys);
+err1:
+	unbind_from_irqhandler(irq, NULL);
+	return ret;
+}
+arch_initcall(xen_pcpu_init);

drivers/xen/platform-pci.c

@@ -109,6 +109,9 @@ static int __devinit platform_pci_init(struct pci_dev *pdev,
 	long mmio_addr, mmio_len;
 	unsigned int max_nr_gframes;
 
+	if (!xen_domain())
+		return -ENODEV;
+
 	i = pci_enable_device(pdev);
 	if (i)
 		return i;

drivers/xen/swiotlb-xen.c

@@ -232,7 +232,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 		return ret;
 
 	if (hwdev && hwdev->coherent_dma_mask)
-		dma_mask = hwdev->coherent_dma_mask;
+		dma_mask = dma_alloc_coherent_mask(hwdev, flags);
 
 	phys = virt_to_phys(ret);
 	dev_addr = xen_phys_to_bus(phys);

drivers/xen/xen-acpi-processor.c

@@ -520,15 +520,18 @@ static int __init xen_acpi_processor_init(void)
 
 		if (!pr_backup) {
 			pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
-			memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
+			if (pr_backup)
+				memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
 		}
 		(void)upload_pm_data(_pr);
 	}
 	rc = check_acpi_ids(pr_backup);
-	if (rc)
-		goto err_unregister;
 
 	kfree(pr_backup);
+	pr_backup = NULL;
+
+	if (rc)
+		goto err_unregister;
 
 	return 0;
 err_unregister:

drivers/xen/xen-pciback/conf_space.c

@@ -124,7 +124,7 @@ static inline u32 merge_value(u32 val, u32 new_val, u32 new_val_mask,
 	return val;
 }
 
-static int pcibios_err_to_errno(int err)
+static int xen_pcibios_err_to_errno(int err)
 {
 	switch (err) {
 	case PCIBIOS_SUCCESSFUL:
@@ -202,7 +202,7 @@ out:
 		       pci_name(dev), size, offset, value);
 
 	*ret_val = value;
-	return pcibios_err_to_errno(err);
+	return xen_pcibios_err_to_errno(err);
 }
 
 int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
@@ -290,7 +290,7 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
 		}
 	}
 
-	return pcibios_err_to_errno(err);
+	return xen_pcibios_err_to_errno(err);
 }
 
 void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev)

drivers/xen/xen-pciback/pci_stub.c

@@ -353,16 +353,16 @@ static int __devinit pcistub_init_device(struct pci_dev *dev)
 	if (err)
 		goto config_release;
 
-	dev_dbg(&dev->dev, "reseting (FLR, D3, etc) the device\n");
-	__pci_reset_function_locked(dev);
-
 	/* We need the device active to save the state. */
 	dev_dbg(&dev->dev, "save state of device\n");
 	pci_save_state(dev);
 	dev_data->pci_saved_state = pci_store_saved_state(dev);
 	if (!dev_data->pci_saved_state)
 		dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
-
+	else {
+		dev_dbg(&dev->dev, "reseting (FLR, D3, etc) the device\n");
+		__pci_reset_function_locked(dev);
+	}
 	/* Now disable the device (this also ensures some private device
 	 * data is setup before we export)
 	 */

drivers/xen/xenbus/xenbus_xs.c

@@ -618,6 +618,23 @@ static struct xenbus_watch *find_watch(const char *token)
 	return NULL;
 }
 
+static void xs_reset_watches(void)
+{
+	int err, supported = 0;
+
+	if (!xen_hvm_domain())
+		return;
+
+	err = xenbus_scanf(XBT_NIL, "control",
+			"platform-feature-xs_reset_watches", "%d", &supported);
+	if (err != 1 || !supported)
+		return;
+
+	err = xs_error(xs_single(XBT_NIL, XS_RESET_WATCHES, "", NULL));
+	if (err && err != -EEXIST)
+		printk(KERN_WARNING "xs_reset_watches failed: %d\n", err);
+}
+
 /* Register callback to watch this node. */
 int register_xenbus_watch(struct xenbus_watch *watch)
 {
@@ -900,5 +917,8 @@ int xs_init(void)
 	if (IS_ERR(task))
 		return PTR_ERR(task);
 
+	/* shutdown watches for kexec boot */
+	xs_reset_watches();
+
 	return 0;
 }