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>

1 files changed, 327 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
new file mode 100644
index 000000000000..a6869e110ce5
--- /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");