[PATCH v2 4/9] ACPI, x86: Extended error log driver for x86 platform

Chen, Gong
2013-10-16T14:56:01Z

This error log driver (a.k.a eMCA driver) is implemented based on
http://www.intel.com/content/www/us/en/architecture-and-technology/enhanced-mca-logging-xeon-paper.htm l.
After errors are captured, more valuable information can be
got with this new enhanced error log driver.

v2 -> v1: eliminate spin_lock & minor fixes suggested by Boris

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
---
arch/x86/include/asm/mce.h | 5 +
arch/x86/kernel/cpu/mcheck/mce.c | 20 +++
drivers/acpi/Kconfig | 9 ++
drivers/acpi/Makefile | 2 +
drivers/acpi/acpi_extlog.c | 319 +++++++++++++++++++++++++++++++++++++++
drivers/acpi/bus.c | 3 +-
include/linux/acpi.h | 1 +
7 files changed, 358 insertions(+), 1 deletion(-)
create mode 100644 drivers/acpi/acpi_extlog.c

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index cbe6b9e..072b2f8 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -16,6 +16,7 @@
#define MCG_EXT_CNT_SHIFT 16
#define MCG_EXT_CNT(c) (((c) & MCG_EXT_CNT_MASK) >> MCG_EXT_CNT_SHIFT)
#define MCG_SER_P (1ULL<<24) /* MCA recovery/new status bits */
+#define MCG_ELOG_P (1ULL<<26) /* Extended error log supported */

/* MCG_STATUS register defines */
#define MCG_STATUS_RIPV (1ULL<<0) /* restart ip valid */
@@ -186,6 +187,10 @@ enum mcp_flags {
MCP_UC = (1 << 1), /* log uncorrected errors */
MCP_DONTLOG = (1 << 2), /* only clear, don't log */
};
+
+void register_elog_handler(int (*f)(const char *, int, int));
+void unregister_elog_handler(int (*f)(const char *, int, int));
+
void machine_check_poll(enum mcp_flags flags, mce_banks_t *b);

int mce_notify_irq(void);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index b3218cd..c11a53f 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -48,6 +48,8 @@

#include "mce-internal.h"

+static int (*mce_ext_err_print)(const char *, int, int) = NULL;
+
static DEFINE_MUTEX(mce_chrdev_read_mutex);

#define rcu_dereference_check_mce(p) \
@@ -576,6 +578,21 @@ static void mce_read_aux(struct mce *m, int i)

DEFINE_PER_CPU(unsigned, mce_poll_count);

+void register_elog_handler(int (*f)(const char *, int, int))
+{
+ mce_ext_err_print = f;
+}
+EXPORT_SYMBOL_GPL(register_elog_handler);
+
+void unregister_elog_handler(int (*f)(const char *, int, int))
+{
+ if (f) {
+ WARN_ON(mce_ext_err_print != f);
+ mce_ext_err_print = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(unregister_elog_handler);
+
/*
* Poll for corrected events or events that happened before reset.
* Those are just logged through /dev/mcelog.
@@ -624,6 +641,9 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
(m.status & (mca_cfg.ser ? MCI_STATUS_S : MCI_STATUS_UC)))
continue;

+ if (mce_ext_err_print)
+ mce_ext_err_print(NULL, m.extcpu, i);
+
mce_read_aux(&m, i);

if (!(flags & MCP_TIMESTAMP))
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 22327e6..819c06b 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -372,4 +372,13 @@ config ACPI_BGRT

source "drivers/acpi/apei/Kconfig"

+config ACPI_EXTLOG
+ tristate "Extended Error Log support"
+ depends on X86_MCE
+ default n
+ help
+ Enhanced MCA Logging allows firmware to provide additional error
+ information to system software, synchronous with MCE or CMCI. This
+ driver adds support for that functionality.
+
endif # ACPI
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index cdaf68b..bce34af 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -82,3 +82,5 @@ processor-$(CONFIG_CPU_FREQ) += processor_perflib.o
obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o

obj-$(CONFIG_ACPI_APEI) += apei/
+
+obj-$(CONFIG_ACPI_EXTLOG) += acpi_extlog.o
diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
new file mode 100644
index 0000000..d55b072
--- /dev/null
+++ b/drivers/acpi/acpi_extlog.c
@@ -0,0 +1,319 @@
+/*
+ * Extended Error Log driver
+ *
+ * Copyright (C) 2013 Intel Corp.
+ * Author: Chen, Gong <gong.chen@intel.com>
+ *
+ * This file is licensed under GPLv2.
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <acpi/acpi_bus.h>
+#include <linux/cper.h>
+#include <linux/ratelimit.h>
+#include <asm/mce.h>
+
+#include "apei/apei-internal.h"
+
+#define EXT_ELOG_ENTRY_MASK GENMASK_ULL(52, 0) /* elog entry address mask */
+
+#define EXTLOG_DSM_REV 0x0
+#define EXTLOG_FN_QUERY 0x0
+#define EXTLOG_FN_ADDR 0x1
+
+#define FLAG_OS_OPTIN BIT(0)
+#define EXTLOG_QUERY_L1_EXIST BIT(1)
+#define ELOG_ENTRY_VALID (1ULL<<63)
+#define ELOG_ENTRY_LEN 0x1000
+
+#define EMCA_BUG \
+ "Can not request iomem region <0x%016llx-0x%016llx> - eMCA disabled\n"
+
+struct extlog_l1_head {
+ u32 ver; /* Header Version */
+ u32 hdr_len; /* Header Length */
+ u64 total_len; /* entire L1 Directory length including this header */
+ u64 elog_base; /* MCA Error Log Directory base address */
+ u64 elog_len; /* MCA Error Log Directory length */
+ u32 flags; /* bit 0 - OS/VMM Opt-in */
+ u8 rev0[12];
+ u32 entries; /* Valid L1 Directory entries per logical processor */
+ u8 rev1[12];
+};
+
+static u8 extlog_dsm_uuid[] = "663E35AF-CC10-41A4-88EA-5470AF055295";
+
+/* L1 table related physical address */
+static u64 elog_base;
+static size_t elog_size;
+static u64 l1_dirbase;
+static size_t l1_size;
+
+/* L1 table related virtual address */
+static void __iomem *extlog_l1_addr;
+static void __iomem *elog_addr;
+
+static void *elog_buf;
+
+static u64 *l1_entry_base;
+static u32 l1_percpu_entry;
+
+#define ELOG_IDX(cpu, bank) \
+ (cpu_physical_id(cpu) * l1_percpu_entry + (bank))
+
+#define ELOG_ENTRY_DATA(idx) \
+ (*(l1_entry_base + (idx)))
+
+#define ELOG_ENTRY_ADDR(phyaddr) \
+ (phyaddr - elog_base + (u8 *)elog_addr)
+
+static struct acpi_generic_status *extlog_elog_entry_check(int cpu, int bank)
+{
+ int idx;
+ u64 data;
+ struct acpi_generic_status *estatus;
+
+ WARN_ON(cpu < 0);
+ idx = ELOG_IDX(cpu, bank);
+ data = ELOG_ENTRY_DATA(idx);
+ if ((data & ELOG_ENTRY_VALID) == 0)
+ return NULL;
+
+ data &= EXT_ELOG_ENTRY_MASK;
+ estatus = (struct acpi_generic_status *)ELOG_ENTRY_ADDR(data);
+
+ /* if no valid data in elog entry, just return */
+ if (estatus->block_status == 0)
+ return NULL;
+
+ return estatus;
+}
+
+static void __print_extlog_rcd(const char *pfx,
+ struct acpi_generic_status *estatus, int cpu)
+{
+ static atomic_t seqno;
+ unsigned int curr_seqno;
+ char pfx_seq[64];
+
+ if (!pfx) {
+ if (estatus->error_severity <= CPER_SEV_CORRECTED)
+ pfx = KERN_INFO;
+ else
+ pfx = KERN_ERR;
+ }
+ curr_seqno = atomic_inc_return(&seqno);
+ snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno);
+ printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
+ cper_estatus_print(pfx_seq, estatus);
+}
+
+static int print_extlog_rcd(const char *pfx,
+ struct acpi_generic_status *estatus, int cpu)
+{
+ /* Not more than 2 messages every 5 seconds */
+ static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
+ static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
+ struct ratelimit_state *ratelimit;
+
+ if (estatus->error_severity == CPER_SEV_CORRECTED ||
+ (estatus->error_severity == CPER_SEV_INFORMATIONAL))
+ ratelimit = &ratelimit_corrected;
+ else
+ ratelimit = &ratelimit_uncorrected;
+ if (__ratelimit(ratelimit)) {
+ __print_extlog_rcd(pfx, estatus, cpu);
+ return 0;
+ }
+
+ return 1;
+}
+
+static int extlog_print(const char *pfx, int cpu, int bank)
+{
+ struct acpi_generic_status *estatus;
+ int rc;
+
+ estatus = extlog_elog_entry_check(cpu, bank);
+ if (estatus == NULL)
+ return -EINVAL;
+
+ memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN);
+ /* clear record status to enable BIOS to update it again */
+ estatus->block_status = 0;
+
+ rc = print_extlog_rcd(pfx, (struct acpi_generic_status *)elog_buf, cpu);
+
+ return rc;
+}
+
+static int extlog_get_dsm(acpi_handle handle, int rev, int func, u64 *ret)
+{
+ struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+ struct acpi_object_list input;
+ union acpi_object params[4], *obj;
+ u8 uuid[16];
+ int i;
+
+ acpi_str_to_uuid(extlog_dsm_uuid, uuid);
+ input.count = 4;
+ input.pointer = params;
+ params[0].type = ACPI_TYPE_BUFFER;
+ params[0].buffer.length = 16;
+ params[0].buffer.pointer = uuid;
+ params[1].type = ACPI_TYPE_INTEGER;
+ params[1].integer.value = rev;
+ params[2].type = ACPI_TYPE_INTEGER;
+ params[2].integer.value = func;
+ params[3].type = ACPI_TYPE_PACKAGE;
+ params[3].package.count = 0;
+ params[3].package.elements = NULL;
+
+ if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf)))
+ return -1;
+
+ *ret = 0;
+ obj = (union acpi_object *)buf.pointer;
+ if (obj->type == ACPI_TYPE_INTEGER)
+ *ret = obj->integer.value;
+ else if (obj->type == ACPI_TYPE_BUFFER) {
+ if (obj->buffer.length <= 8) {
+ for (i = 0; i < obj->buffer.length; i++)
+ *ret |= (obj->buffer.pointer[i] << (i * 8));
+ }
+ }
+ kfree(buf.pointer);
+
+ return 0;
+}
+
+static bool extlog_get_l1addr(void)
+{
+ acpi_handle handle;
+ u64 ret;
+
+ if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
+ return false;
+
+ if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_QUERY, &ret) ||
+ !(ret & EXTLOG_QUERY_L1_EXIST))
+ return false;
+
+ if (extlog_get_dsm(handle, EXTLOG_DSM_REV, EXTLOG_FN_ADDR, &ret))
+ return false;
+
+ l1_dirbase = ret;
+ /* Spec says L1 directory must be 4K aligned, bail out if it isn't */
+ if (l1_dirbase & ((1 << 12) - 1)) {
+ pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",
+ l1_dirbase);
+ return false;
+ }
+
+ return true;
+}
+
+static int __init extlog_init(void)
+{
+ struct extlog_l1_head *l1_head;
+ void __iomem *extlog_l1_hdr;
+ size_t l1_hdr_size;
+ struct resource *r;
+ u64 cap;
+ int rc;
+
+ rc = -ENODEV;
+
+ rdmsrl(MSR_IA32_MCG_CAP, cap);
+ if (!(cap & MCG_ELOG_P))
+ return rc;
+
+ if (!extlog_get_l1addr())
+ return rc;
+
+ rc = -EINVAL;
+ /* get L1 header to fetch necessary information */
+ l1_hdr_size = sizeof(struct extlog_l1_head);
+ r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR");
+ if (!r) {
+ pr_warn(FW_BUG EMCA_BUG,
+ (unsigned long long)l1_dirbase,
+ (unsigned long long)l1_dirbase + l1_hdr_size);
+ goto err;
+ }
+
+ extlog_l1_hdr = acpi_os_map_memory(l1_dirbase, l1_hdr_size);
+ l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
+ l1_size = l1_head->total_len;
+ l1_percpu_entry = l1_head->entries;
+ elog_base = l1_head->elog_base;
+ elog_size = l1_head->elog_len;
+ acpi_os_unmap_memory(extlog_l1_hdr, l1_hdr_size);
+ release_mem_region(l1_dirbase, l1_hdr_size);
+
+ /* remap L1 header again based on completed information */
+ r = request_mem_region(l1_dirbase, l1_size, "L1 Table");
+ if (!r) {
+ pr_warn(FW_BUG EMCA_BUG,
+ (unsigned long long)l1_dirbase,
+ (unsigned long long)l1_dirbase + l1_size);
+ goto err;
+ }
+ extlog_l1_addr = acpi_os_map_memory(l1_dirbase, l1_size);
+ l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
+
+ /* remap elog table */
+ r = request_mem_region(elog_base, elog_size, "Elog Table");
+ if (!r) {
+ pr_warn(FW_BUG EMCA_BUG,
+ (unsigned long long)elog_base,
+ (unsigned long long)elog_base + elog_size);
+ goto err_release_l1_dir;
+ }
+ elog_addr = acpi_os_map_memory(elog_base, elog_size);
+
+ rc = -ENOMEM;
+ /* allocate buffer to save elog record */
+ elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL);
+ if (elog_buf == NULL)
+ goto err_release_elog;
+
+ register_elog_handler(extlog_print);
+ /* enable OS to be involved to take over management from BIOS */
+ ((struct extlog_l1_head *)extlog_l1_addr)->flags |= FLAG_OS_OPTIN;
+
+ return 0;
+
+err_release_elog:
+ if (elog_addr)
+ acpi_os_unmap_memory(elog_addr, elog_size);
+ release_mem_region(elog_base, elog_size);
+err_release_l1_dir:
+ if (extlog_l1_addr)
+ acpi_os_unmap_memory(extlog_l1_addr, l1_size);
+ release_mem_region(l1_dirbase, l1_size);
+err:
+ pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
+ return rc;
+}
+
+static void __exit extlog_exit(void)
+{
+ unregister_elog_handler(extlog_print);
+ ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
+ if (extlog_l1_addr)
+ acpi_os_unmap_memory(extlog_l1_addr, l1_size);
+ if (elog_addr)
+ acpi_os_unmap_memory(elog_addr, elog_size);
+ release_mem_region(elog_base, elog_size);
+ release_mem_region(l1_dirbase, l1_size);
+ kfree(elog_buf);
+}
+
+module_init(extlog_init);
+module_exit(extlog_exit);
+
+MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>");
+MODULE_DESCRIPTION("Extended Error Log Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index b587ec8..e1bd9a1 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -174,7 +174,7 @@ static void acpi_print_osc_error(acpi_handle handle,
printk("\n");
}

-static acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
+acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
{
int i;
static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
@@ -195,6 +195,7 @@ static acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
}
return AE_OK;
}
+EXPORT_SYMBOL_GPL(acpi_str_to_uuid);

acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
{
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index a5db4ae..c30bac8 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -311,6 +311,7 @@ struct acpi_osc_context {
#define OSC_INVALID_REVISION_ERROR 8
#define OSC_CAPABILITIES_MASK_ERROR 16

+acpi_status acpi_str_to_uuid(char *str, u8 *uuid);
acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context);

/* platform-wide _OSC bits */
--
1.8.4.rc3