Patchwork [1/4] x86, mce: Xeon75xx specific interface to get corrected memory error information

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Submitter Andy Whitcroft
Date Feb. 10, 2010, 4:20 p.m.
Message ID <1265818860-32016-2-git-send-email-apw@canonical.com>
Download mbox | patch
Permalink /patch/45044/
State Accepted
Delegated to: Andy Whitcroft
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Comments

Andy Whitcroft - Feb. 10, 2010, 4:20 p.m.
From: Andi Kleen <andi@firstfloor.org>

commit c773f70fd6b53ee646727f871833e53649907264 upstream (linux-2.6-tip)

Xeon 75xx doesn't log physical addresses on corrected machine check
events in the standard architectural MSRs. Instead the address has to
be retrieved in a model specific way. This makes it impossible to do
predictive failure analysis.

Implement cpu model specific code to do this in mce-xeon75xx.c using a
new hook that is called from the generic poll code. The code retrieves
the physical address/DIMM of the last corrected error from the
platform and makes the address look like a standard architectural MCA
address for further processing.

In addition the DIMM information is retrieved and put into two new
aux0/aux1 fields in struct mce.  These fields are specific to a given
CPU.  These fields can then be decoded by mcelog into specific DIMM
information.  The latest mcelog version has support for this.

Longer term this will be likely in a different output format, but
short term that seemed like the least intrusive solution. Older mcelog
can deal with an extended record.

There's no code to print this information on a panic because this only
works for corrected errors, and corrected errors do not usually result
in panics.

The act of retrieving the DIMM/PA information can take some time, so
this code has a rate limit to avoid taking too much CPU time on a
error flood.

The whole thing can be loaded as a module and has suitable PCI-IDs so
that it can be auto-loaded by a distribution.  The code also checks
explicitely for the expected CPU model number to make sure this code
doesn't run anywhere else.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
LKML-Reference: <20100121221711.GA8242@basil.fritz.box>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
---
 arch/x86/Kconfig                          |    8 +
 arch/x86/include/asm/mce.h                |    2 +
 arch/x86/kernel/cpu/mcheck/Makefile       |    1 +
 arch/x86/kernel/cpu/mcheck/mce-internal.h |    1 +
 arch/x86/kernel/cpu/mcheck/mce-xeon75xx.c |  427 +++++++++++++++++++++++++++++
 arch/x86/kernel/cpu/mcheck/mce.c          |   12 +
 arch/x86/kernel/e820.c                    |    3 +-
 7 files changed, 453 insertions(+), 1 deletions(-)
 create mode 100644 arch/x86/kernel/cpu/mcheck/mce-xeon75xx.c

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f466491..8b4d299 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -833,6 +833,14 @@  config X86_MCE_INTEL
 	   Additional support for intel specific MCE features such as
 	   the thermal monitor.
 
+config X86_MCE_XEON75XX
+	tristate "Intel Xeon 7500 series corrected memory error driver"
+	depends on X86_MCE_INTEL
+	---help---
+	   Add support for a Intel Xeon 7500 series specific memory error driver.
+	   This allows to report the DIMM and physical address on a corrected
+	   memory error machine check event.
+
 config X86_MCE_AMD
 	def_bool y
 	prompt "AMD MCE features"
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index a479023..9171578 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -67,6 +67,8 @@  struct mce {
 	__u32 socketid;	/* CPU socket ID */
 	__u32 apicid;	/* CPU initial apic ID */
 	__u64 mcgcap;	/* MCGCAP MSR: machine check capabilities of CPU */
+	__u64 aux0;	/* model specific */
+	__u64 aux1;	/* model specific */
 };
 
 /*
diff --git a/arch/x86/kernel/cpu/mcheck/Makefile b/arch/x86/kernel/cpu/mcheck/Makefile
index 4ac6d48..16606f4 100644
--- a/arch/x86/kernel/cpu/mcheck/Makefile
+++ b/arch/x86/kernel/cpu/mcheck/Makefile
@@ -2,6 +2,7 @@  obj-y				=  mce.o mce-severity.o
 
 obj-$(CONFIG_X86_ANCIENT_MCE)	+= winchip.o p5.o
 obj-$(CONFIG_X86_MCE_INTEL)	+= mce_intel.o
+obj-$(CONFIG_X86_MCE_XEON75XX)	+= mce-xeon75xx.o
 obj-$(CONFIG_X86_MCE_AMD)	+= mce_amd.o
 obj-$(CONFIG_X86_MCE_THRESHOLD) += threshold.o
 obj-$(CONFIG_X86_MCE_INJECT)	+= mce-inject.o
diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index 32996f9..d5b7eec 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -28,3 +28,4 @@  extern int mce_ser;
 
 extern struct mce_bank *mce_banks;
 
+extern void (*cpu_specific_poll)(struct mce *);
diff --git a/arch/x86/kernel/cpu/mcheck/mce-xeon75xx.c b/arch/x86/kernel/cpu/mcheck/mce-xeon75xx.c
new file mode 100644
index 0000000..67ad39b
--- /dev/null
+++ b/arch/x86/kernel/cpu/mcheck/mce-xeon75xx.c
@@ -0,0 +1,427 @@ 
+/*
+ * Xeon 7500 series specific machine check support code.
+ * Copyright 2009, 2010 Intel Corporation
+ * Author: Andi Kleen
+ *
+ * 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; version 2
+ * of the License.
+ *
+ * Implement Xeon 7500 series specific code to retrieve the physical address
+ * and DIMM information for corrected memory errors.
+ *
+ * Interface: mce->aux0/aux1 is mapped to a struct pfa_dimm with pad
+ * redefined to DIMM valid bits. Consumers check CPUID and bank and
+ * then interpret aux0/aux1
+ */
+
+/* #define DEBUG 1 */	/* disable for production */
+#define pr_fmt(x) "MCE: " x
+
+#include <linux/moduleparam.h>
+#include <linux/pci_ids.h>
+#include <linux/hrtimer.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <asm/processor.h>
+#include <asm/e820.h>
+#include <asm/mce.h>
+#include <asm/io.h>
+
+#include "mce-internal.h"
+
+#define PFA_SIG "$PFA"
+#define PFA_SIG_LEN 4
+
+/* DIMM description */
+struct aux_pfa_dimm {
+	u8  fbd_channel_id;
+	u8  ddr_channel_id;
+	u8  ddr_dimm_id;
+	u8  ddr_rank_id;
+	u8  ddr_dimm_bank_id;
+	u8  ddr_dimm_row_id;
+	u8  ddr_dimm_column_id;
+	u8  valid;
+} __attribute__((packed));
+
+struct pfa_dimm {
+	u8  fbd_channel_id;
+	u8  ddr_channel_id;
+	u8  ddr_dimm_id;
+	u8  ddr_rank_id;
+	u8  ddr_dimm_bank_id;
+	u32 ddr_dimm_row_id;
+	u32 ddr_dimm_column_id;
+} __attribute__((packed));
+
+/* Memory translation table in memory. */
+struct pfa_table {
+	u8  sig[PFA_SIG_LEN];	/* Signature: '$PFA' */
+	u16 len;		/* total length */
+	u16 revision;		/* 0x11 */
+	u8  checksum;		/* 8bit sum to zero */
+	u8  db_value;		/* mailbox port command value */
+	u8  db_port;		/* mailbox port */
+	/* end of header; end of checksum */
+	u8  command;		/* input command */
+	u32 valid;		/* valid input/output bits */
+	u16 status;		/* output status */
+	u8  socket_id;		/* input socket id*/
+	u8  bank_id;		/* input MCE bank id */
+	u32 pad1;
+	u64 mbox_address;
+	u64 physical_addr;	/* physical address */
+	struct pfa_dimm dimm[2];
+	/*
+	 * topology information follows: not used for now.
+	 */
+} __attribute__((packed));
+
+/* DIMM valid bits in valid: DIMM0: 8..12; DIMM1 16..20 */
+#define DIMM_VALID_BITS(val, num) (((val) >> (4 + (num) * 8)) & DIMM_VALID_ALL)
+#define DIMM_SET_VALID(val, num)  ((val) << (4 + (num) * 8))
+
+enum {
+	MCE_BANK_MBOX0		= 8,
+	MCE_BANK_MBOX1		= 9,
+
+	PFA_REVISION		= 0x11,		/* v1.1 */
+
+	/* Status bits for valid field */
+	PFA_VALID_MA            = (1 << 0),
+	PFA_VALID_SOCKETID      = (1 << 1),
+	PFA_VALID_BANKID        = (1 << 2),
+	PFA_VALID_PA            = (1 << 3),
+
+	/* DIMM valid bits in valid */
+	/* use with DIMM_VALID_BITS/DIMM_SET_VALID for pfa->valid */
+	DIMM_VALID_FBD_CHAN      = (1 << 0),
+	DIMM_VALID_DDR_CHAN      = (1 << 1),
+	DIMM_VALID_DDR_DIMM      = (1 << 2),
+	DIMM_VALID_DDR_RANK      = (1 << 3),
+	DIMM_VALID_DIMM_BANK     = (1 << 4),
+	DIMM_VALID_DIMM_ROW      = (1 << 5),
+	DIMM_VALID_DIMM_COLUMN   = (1 << 6),
+	DIMM_VALID_ALL		 = 0x7f,
+
+	PFA_DIMM_VALID_MASK	 = DIMM_SET_VALID(DIMM_VALID_ALL, 0)
+				 | DIMM_SET_VALID(DIMM_VALID_ALL, 1),
+
+	/* Values for status field */
+	PFA_STATUS_SUCCESS      = 0,
+	PFA_STATUS_SOCKET_INVALID  = (1 << 1),
+	PFA_STATUS_MBOX_INVALID = (1 << 2),
+	PFA_STATUS_MA_INVALID   = (1 << 3),
+	PFA_STATUS_PA_INVALID   = (1 << 4),
+
+	/* Values for command field */
+	PFA_CMD_GET_MEM_CORR_ERR_PA = 0,
+	PFA_CMD_PA_TO_DIMM_ADDR     = 1,
+	PFA_CMD_DIMM_TO_PA	    = 2,
+	PFA_CMD_GET_TOPOLOGY	    = 3,
+
+	/* PCI device IDs and the base register */
+	ICH_PFA_CFG             = 0x8c, /* SCRATCH4 */
+	PCI_DEVICE_ID_BXB_ICH_LEGACY0 = 0x3422,
+};
+
+static struct pfa_table *pfa_table __read_mostly;
+static int memerr_max_conv_rate __read_mostly = 100;
+static int memerr_min_interval __read_mostly = 500;
+static int pfa_lost;	/* for diagnosis */
+
+enum {
+	RATE_LIMIT_PERIOD = USEC_PER_SEC, /* in us; period of rate limit */
+};
+
+module_param(memerr_max_conv_rate, int, 0644);
+MODULE_PARM_DESC(memerr_max_conv_rate,
+	"Maximum number of memory error conversions each second; 0 to disable");
+module_param(memerr_min_interval, int, 0644);
+MODULE_PARM_DESC(memerr_min_interval,
+	"Minimum time delta between two memory conversions; in us; default 500");
+
+static int notest;
+static int nocsum;
+module_param(notest, int, 0);
+module_param(nocsum, int, 0);
+
+static u64 encode_dimm(struct pfa_dimm *d, u8 valid)
+{
+	union {
+		struct aux_pfa_dimm d;
+		u64 v;
+	} p;
+
+	BUILD_BUG_ON(sizeof(struct aux_pfa_dimm) != sizeof(u64));
+	p.d.fbd_channel_id = d->fbd_channel_id;
+	p.d.ddr_channel_id = d->ddr_channel_id;
+	p.d.ddr_dimm_id = d->ddr_dimm_id;
+	p.d.ddr_rank_id = d->ddr_rank_id;
+	p.d.ddr_dimm_bank_id = d->ddr_dimm_bank_id;
+	p.d.ddr_dimm_row_id = d->ddr_dimm_row_id;
+	if (p.d.ddr_dimm_row_id != d->ddr_dimm_row_id) /* truncated? */
+		valid &= ~DIMM_VALID_DIMM_ROW;
+	p.d.ddr_dimm_column_id = d->ddr_dimm_column_id;
+	if (p.d.ddr_dimm_column_id != d->ddr_dimm_column_id)
+		valid &= ~DIMM_VALID_DIMM_COLUMN;
+	p.d.valid = valid;
+	pr_debug("PFA fbd_ch %u ddr_ch %u dimm %u rank %u bank %u valid %x\n",
+		 d->fbd_channel_id,
+		 d->ddr_channel_id,
+		 d->ddr_dimm_id,
+		 d->ddr_rank_id,
+		 d->ddr_dimm_bank_id,
+		 valid);
+	return p.v;
+}
+
+static u8 csum(u8 *table, u16 len)
+{
+	u8 sum = 0;
+	int i;
+	for (i = 0; i < len; i++)
+		sum += *table++;
+	return sum;
+}
+
+/*
+ * Execute a command through the mailbox interface.
+ */
+static int
+pfa_command(unsigned bank, unsigned socketid, unsigned command, unsigned valid)
+{
+	pfa_table->bank_id = bank;
+	pfa_table->socket_id = socketid;
+	pfa_table->valid = valid | PFA_VALID_SOCKETID;
+	pfa_table->command = command;
+
+	outb(pfa_table->db_value, pfa_table->db_port);
+
+	mb();	/* Reread fields after they got changed */
+
+	if (pfa_table->status != PFA_STATUS_SUCCESS) {
+		pr_debug("Memory PFA command %d failed: socket:%d bank:%d status:%x\n",
+			command, socketid, bank, pfa_table->status);
+		return -pfa_table->status;
+	}
+	return 0;
+}
+
+/*
+ * Retrieve physical address and DIMMs.
+ */
+static int translate_memory_error(struct mce *m)
+{
+	struct pfa_table *pfa = pfa_table;
+	u64 status;
+	int ret;
+	u32 valid;
+	int cpu = smp_processor_id();
+
+	/* Make sure our structures match the specification */
+	BUILD_BUG_ON(offsetof(struct pfa_table, physical_addr) != 0x20);
+	BUILD_BUG_ON(offsetof(struct pfa_table, status) != 0x10);
+	BUILD_BUG_ON(offsetof(struct pfa_table, physical_addr) != 0x20);
+	BUILD_BUG_ON(offsetof(struct pfa_table, dimm[1].ddr_dimm_column_id) !=
+			0x3e);
+
+	/* Ask for PA/DIMMs of last error */
+	if (pfa_command(m->bank, m->socketid,
+			PFA_CMD_GET_MEM_CORR_ERR_PA, PFA_VALID_BANKID) < 0)
+		return -1;
+
+	/*
+	 * Recheck machine check bank. If the overflow bit was set
+	 * there was a race. Don't use the information in this case.
+	 */
+	rdmsrl(MSR_IA32_MCx_STATUS(m->bank), status);
+	if (status & MCI_STATUS_OVER) {
+		pr_debug("%d: overflow race on bank %d\n", cpu, m->bank);
+		return -1;
+	}
+
+	ret = -1;
+	valid = pfa->valid;
+	if (valid & PFA_VALID_PA) {
+		m->status |= MCI_STATUS_ADDRV;
+		m->addr = pfa_table->physical_addr;
+		pr_debug("%d: got physical address %llx valid %x\n",
+			cpu, m->addr, valid);
+		ret = 0;
+	}
+
+	/* When DIMM information was supplied pass it out */
+	if (valid & PFA_DIMM_VALID_MASK) {
+		m->aux0 = encode_dimm(&pfa->dimm[0], DIMM_VALID_BITS(valid, 0));
+		m->aux1 = encode_dimm(&pfa->dimm[1], DIMM_VALID_BITS(valid, 1));
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/*
+ * Xeon 75xx specific mce poll method to retrieve the physical address
+ * and DIMM information.
+ */
+static void xeon75xx_mce_poll(struct mce *m)
+{
+	static DEFINE_SPINLOCK(convert_lock); /* Protect table and static */
+	static unsigned long cperm;
+	static ktime_t last, last_int;
+	unsigned long flags;
+	ktime_t now;
+	s64 delta;
+
+	/* Memory error? */
+	if (m->bank != MCE_BANK_MBOX0 && m->bank != MCE_BANK_MBOX1)
+		return;
+	if (m->status & MCI_STATUS_OVER)
+		return;
+	if (memerr_max_conv_rate == 0)
+		return;
+
+	spin_lock_irqsave(&convert_lock, flags);
+	/*
+	 * Rate limit conversions. The conversion takes some time,
+	 * but it's not good to use all the CPU time during a error
+	 * flood.
+	 * Enforce maximum number per second and minimum interval.
+	 * The ktime call should use TSC on this machine and be fast.
+	 */
+	now = ktime_get();
+	delta = ktime_us_delta(now, last);
+	if (delta >= RATE_LIMIT_PERIOD) {
+		cperm = 0;
+		last = now;
+	}
+	if (ktime_us_delta(now, last_int) >= memerr_min_interval &&
+	   ++cperm <= memerr_max_conv_rate) {
+		if (translate_memory_error(m) < 0) {
+			/* On error stop converting for the next second */
+			cperm = memerr_max_conv_rate;
+			pr_debug("PFA translation failed\n");
+		}
+	} else
+		pfa_lost++;
+	last_int = now;
+	spin_unlock_irqrestore(&convert_lock, flags);
+}
+
+static struct pci_device_id bxb_mce_pciids[] = {
+	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_BXB_ICH_LEGACY0) },
+	{}
+};
+
+static int __init xeon75xx_mce_init(void)
+{
+	u32 addr = 0;
+	struct pci_dev *dev;
+
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
+	    boot_cpu_data.x86 != 6 ||
+	    boot_cpu_data.x86_model != 0x2e)
+		return -ENODEV;
+
+	/*
+	 * Get table address from register in IOH.
+	 * This just looks up the device, because we don't want to "own" it.
+	 */
+	dev = NULL;
+	while ((dev = pci_get_device(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, dev))
+			!= NULL) {
+		if (!pci_match_id(bxb_mce_pciids, dev))
+			continue;
+		pci_read_config_dword(dev, ICH_PFA_CFG, &addr);
+		if (addr)
+			break;
+	}
+	pci_dev_put(dev);
+	if (!addr)
+		return -ENODEV;
+
+	if (!e820_all_mapped(addr, addr + PAGE_SIZE, E820_RESERVED)) {
+		pr_info("PFA table at %x not e820 reserved\n", addr);
+		return -ENODEV;
+	}
+
+	pfa_table = (__force struct pfa_table *)ioremap_cache(addr, PAGE_SIZE);
+	if (!pfa_table) {
+		pr_err("Cannot map PFA table at %x\n", addr);
+		return -EIO;
+	}
+
+	if (memcmp(&pfa_table->sig, PFA_SIG, PFA_SIG_LEN) ||
+	    pfa_table->len < sizeof(struct pfa_table) ||
+	    /* assume newer versions are compatible */
+	    pfa_table->revision < PFA_REVISION) {
+		pr_info("PFA table at %x invalid\n", addr);
+		goto error_unmap;
+	}
+
+	if (!nocsum && csum((u8 *)pfa_table,
+				offsetof(struct pfa_table, command))) {
+		pr_info("PFA table at %x length %u has invalid checksum\n",
+			addr, pfa_table->len);
+		goto error_unmap;
+	}
+
+	/* Not strictly needed today */
+	if (pfa_table->len > PAGE_SIZE) {
+		unsigned len = roundup(pfa_table->len, PAGE_SIZE);
+		iounmap(pfa_table);
+		pfa_table = (__force void *)ioremap_cache(addr, len);
+		if (!pfa_table) {
+			pr_err("Cannot remap %u bytes PFA table at %x\n",
+				len, addr);
+			return -EIO;
+		}
+	}
+
+	if (!notest) {
+		int status = pfa_command(0, 0, PFA_CMD_GET_TOPOLOGY, 0);
+		if (status < 0) {
+			pr_err("Test of PFA table failed: %x\n", -status);
+			goto error_unmap;
+		}
+	}
+
+	pr_info("Found Xeon75xx PFA memory error translation table at %x\n",
+		addr);
+	mb();
+	cpu_specific_poll = xeon75xx_mce_poll;
+	return 0;
+
+error_unmap:
+	iounmap(pfa_table);
+	return -ENODEV;
+}
+
+MODULE_DEVICE_TABLE(pci, bxb_mce_pciids);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andi Kleen");
+MODULE_DESCRIPTION("Intel Xeon 75xx specific DIMM error reporting");
+
+#ifdef CONFIG_MODULE
+static void __exit xeon75xx_mce_exit(void)
+{
+	cpu_specific_poll = NULL;
+	wmb();
+	/* Wait for all machine checks to finish before really unloading */
+	synchronize_rcu();
+	iounmap(pfa_table);
+}
+
+module_init(xeon75xx_mce_init);
+module_exit(xeon75xx_mce_exit);
+#else
+/* When built-in run as soon as the PCI subsystem is up */
+fs_initcall(xeon75xx_mce_init);
+#endif
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 0f16a2b..2067627 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -91,6 +91,9 @@  static void default_decode_mce(struct mce *m)
 	pr_emerg("Run the message through 'mcelog --ascii' to decode.\n");
 }
 
+void				(*cpu_specific_poll)(struct mce *);
+EXPORT_SYMBOL_GPL(cpu_specific_poll);
+
 /*
  * CPU/chipset specific EDAC code can register a callback here to print
  * MCE errors in a human-readable form:
@@ -350,6 +353,11 @@  static void mce_wrmsrl(u32 msr, u64 v)
 	wrmsrl(msr, v);
 }
 
+static int under_injection(void)
+{
+	return __get_cpu_var(injectm).finished;
+}
+
 /*
  * Simple lockless ring to communicate PFNs from the exception handler with the
  * process context work function. This is vastly simplified because there's
@@ -553,6 +561,10 @@  void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
 
 		if (!(flags & MCP_TIMESTAMP))
 			m.tsc = 0;
+
+		if (cpu_specific_poll && !under_injection() && !mce_dont_log_ce)
+			cpu_specific_poll(&m);
+
 		/*
 		 * Don't get the IP here because it's unlikely to
 		 * have anything to do with the actual error location.
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index d17d482..c9075ee 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -79,7 +79,7 @@  EXPORT_SYMBOL_GPL(e820_any_mapped);
  * Note: this function only works correct if the e820 table is sorted and
  * not-overlapping, which is the case
  */
-int __init e820_all_mapped(u64 start, u64 end, unsigned type)
+int e820_all_mapped(u64 start, u64 end, unsigned type)
 {
 	int i;
 
@@ -106,6 +106,7 @@  int __init e820_all_mapped(u64 start, u64 end, unsigned type)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(e820_all_mapped);
 
 /*
  * Add a memory region to the kernel e820 map.