v4.19.13 snapshot.
diff --git a/drivers/xen/mcelog.c b/drivers/xen/mcelog.c
new file mode 100644
index 0000000..b8bf61a
--- /dev/null
+++ b/drivers/xen/mcelog.c
@@ -0,0 +1,417 @@
+/******************************************************************************
+ * 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.
+ */
+
+#define pr_fmt(fmt) "xen_mcelog: " fmt
+
+#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>
+
+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 __poll_t xen_mce_chrdev_poll(struct file *file, poll_table *wait)
+{
+ poll_wait(file, &xen_mce_chrdev_wait, wait);
+
+ if (xen_mcelog.next)
+ return EPOLLIN | EPOLLRDNORM;
+
+ 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_warn("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_warn("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_warn("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;
+ 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("Failed to fetch %surgent error log\n",
+ flags == XEN_MC_URGENT ? "" : "non");
+ 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_warn("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("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("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("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;
+ set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
+ ret = HYPERVISOR_mca(&mc_op);
+ if (ret) {
+ pr_err("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("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("Failed to bind virq\n");
+ kfree(g_physinfo);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int __init xen_late_init_mcelog(void)
+{
+ int ret;
+
+ /* Only DOM0 is responsible for MCE logging */
+ if (!xen_initial_domain())
+ return -ENODEV;
+
+ /* register character device /dev/mcelog for xen mcelog */
+ ret = misc_register(&xen_mce_chrdev_device);
+ if (ret)
+ return ret;
+
+ ret = bind_virq_for_mce();
+ if (ret)
+ goto deregister;
+
+ pr_info("/dev/mcelog registered by Xen\n");
+
+ return 0;
+
+deregister:
+ misc_deregister(&xen_mce_chrdev_device);
+ return ret;
+}
+device_initcall(xen_late_init_mcelog);