ACPI, x86: Extended error log driver for x86 platform
This H/W 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.html
After errors are captured, more detailed platform specific information
can be got via this new enhanced H/W error log driver. Most notably we
can track memory errors back to the DIMM slot silk screen label.
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
new file mode 100644
index 0000000..a6869e1
--- /dev/null
+++ b/drivers/acpi/acpi_extlog.c
@@ -0,0 +1,327 @@
+/*
+ * 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/cpu.h>
+#include <asm/mce.h>
+
+#include "apei/apei-internal.h"
+
+#define EXT_ELOG_ENTRY_MASK GENMASK_ULL(51, 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(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct mce *mce = (struct mce *)data;
+ int bank = mce->bank;
+ int cpu = mce->extcpu;
+ struct acpi_generic_status *estatus;
+ int rc;
+
+ estatus = extlog_elog_entry_check(cpu, bank);
+ if (estatus == NULL)
+ return NOTIFY_DONE;
+
+ 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(NULL, (struct acpi_generic_status *)elog_buf, cpu);
+
+ return NOTIFY_DONE;
+}
+
+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 struct notifier_block extlog_mce_dec = {
+ .notifier_call = extlog_print,
+};
+
+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;
+
+ mce_register_decode_chain(&extlog_mce_dec);
+ /* 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)
+{
+ mce_unregister_decode_chain(&extlog_mce_dec);
+ ((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 MCA Error Log Driver");
+MODULE_LICENSE("GPL");