[PATCH 3/3] ia64: Call migration code on correctable errors v5

From: Russ Anderson
Date: Fri May 16 2008 - 15:24:21 EST

Migrate data off pages with correctable memory errors. This patch is the
ia64 specific piece. It connects the CPE handler to the page migration
code. It is implemented as a kernel loadable module, similar to the mca
recovery code (mca_recovery.ko). This allows the feature to be turned off
by uninstalling the module.


Signed-off-by: Russ Anderson <rja@xxxxxxx>

---
arch/ia64/Kconfig | 9
arch/ia64/kernel/Makefile | 1
arch/ia64/kernel/cpe_migrate.c | 418 +++++++++++++++++++++++++++++++++++++++++
arch/ia64/kernel/mca.c | 34 +++
include/asm-ia64/mca.h | 5
include/asm-ia64/page.h | 1
mm/migrate.c | 5
7 files changed, 472 insertions(+), 1 deletion(-)

Index: linus/arch/ia64/kernel/Makefile
===================================================================
--- linus.orig/arch/ia64/kernel/Makefile 2008-05-14 15:36:06.822294012 -0500
+++ linus/arch/ia64/kernel/Makefile 2008-05-15 12:59:05.906697854 -0500
@@ -27,6 +27,7 @@ obj-$(CONFIG_PERFMON) += perfmon_defaul
obj-$(CONFIG_IA64_CYCLONE) += cyclone.o
obj-$(CONFIG_CPU_FREQ) += cpufreq/
obj-$(CONFIG_IA64_MCA_RECOVERY) += mca_recovery.o
+obj-$(CONFIG_IA64_CPE_MIGRATE) += cpe_migrate.o
obj-$(CONFIG_KPROBES) += kprobes.o jprobes.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o crash.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
Index: linus/arch/ia64/kernel/cpe_migrate.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linus/arch/ia64/kernel/cpe_migrate.c 2008-05-15 12:59:05.914698840 -0500
@@ -0,0 +1,418 @@
+/*
+ * File: cpe_migrate.c
+ * Purpose: Migrate data from physical pages with excessive correctable
+ * errors to new physical pages. Keep the old pages on a discard
+ * list.
+ *
+ * Copyright (C) 2008 SGI - Silicon Graphics Inc.
+ * Copyright (C) 2008 Russ Anderson <rja@xxxxxxx>
+ */
+
+#include <linux/sysdev.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/workqueue.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/vmalloc.h>
+#include <linux/migrate.h>
+#include <linux/page-isolation.h>
+#include <linux/memcontrol.h>
+#include <linux/kobject.h>
+
+#include <asm/page.h>
+#include <asm/system.h>
+#include <asm/sn/sn_cpuid.h>
+#include <asm/mca.h>
+
+#define BADRAM_BASENAME "badram"
+#define CE_HISTORY_LENGTH 30
+
+struct cpe_info {
+ u64 paddr;
+ u16 node;
+};
+static struct cpe_info cpe[CE_HISTORY_LENGTH];
+
+static int cpe_polling_enabled = 1;
+static int cpe_head;
+static int cpe_tail;
+static int work_scheduled;
+
+DEFINE_SPINLOCK(cpe_migrate_lock);
+
+static void
+get_physical_address(void *buffer, u64 *paddr, u16 *node)
+{
+ sal_log_record_header_t *rh;
+ sal_log_mem_dev_err_info_t *mdei;
+ ia64_err_rec_t *err_rec;
+ sal_log_platform_err_info_t *plat_err;
+ efi_guid_t guid;
+
+ err_rec = buffer;
+ rh = &err_rec->sal_elog_header;
+ *paddr = 0;
+ *node = 0;
+
+ /*
+ * Make sure it is a corrected error.
+ */
+ if (rh->severity != sal_log_severity_corrected)
+ return;
+
+ plat_err = (sal_log_platform_err_info_t *)&err_rec->proc_err;
+
+ guid = plat_err->mem_dev_err.header.guid;
+ if (efi_guidcmp(guid, SAL_PLAT_MEM_DEV_ERR_SECT_GUID) == 0) {
+ /*
+ * Memory cpe
+ */
+ mdei = &plat_err->mem_dev_err;
+ if (mdei->valid.oem_data) {
+ if (mdei->valid.physical_addr)
+ *paddr = mdei->physical_addr;
+
+ if (mdei->valid.node) {
+ if (ia64_platform_is("sn2"))
+ *node = nasid_to_cnodeid(mdei->node);
+ else
+ *node = mdei->node;
+ }
+ }
+ }
+}
+
+static struct page *
+alloc_migrate_page(struct page *ignored, unsigned long node, int **x)
+{
+
+ return alloc_pages_node(node, GFP_HIGHUSER_MOVABLE, 0);
+}
+
+static int
+validate_paddr_page(u64 paddr)
+{
+ struct page *page;
+
+ if (!paddr)
+ return -EINVAL;
+
+ if (!ia64_phys_addr_valid(paddr))
+ return -EINVAL;
+
+ if (!pfn_valid(paddr >> PAGE_SHIFT))
+ return -EINVAL;
+
+ page = phys_to_page(paddr);
+ if (PageMemError(page))
+ /*
+ * The page has already been marked bad.
+ */
+ return -EINVAL;
+ return 0;
+}
+
+static int
+ia64_mca_cpe_move_page(u64 paddr, u32 node)
+{
+ LIST_HEAD(pagelist);
+ struct page *page;
+ int ret;
+
+ ret = validate_paddr_page(paddr);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * convert physical address to page number
+ */
+ page = phys_to_page(paddr);
+
+ migrate_prep();
+ ret = isolate_lru_page(page, &pagelist);
+ if (ret)
+ return ret;
+
+ SetPageMemError(page); /* Mark the page as bad */
+ ret = migrate_pages(&pagelist, alloc_migrate_page, node);
+ if (ret == 0)
+ list_add_tail(&page->lru, &badpagelist);
+ else
+ /*
+ * The page failed to migrate and is not on the bad page list.
+ * Clearing the error bit will allow another attempt to migrate
+ * if it gets another correctable error.
+ */
+ ClearPageMemError(page);
+
+ return 0;
+}
+
+/*
+ * ia64_mca_cpe_migrate
+ * The worker that does the actual migration. It pulls a
+ * physical address off the list and calls the migration code.
+ */
+static void
+ia64_mca_cpe_migrate(struct work_struct *unused)
+{
+ int ret;
+ u64 paddr;
+ u16 node;
+
+ do {
+ paddr = cpe[cpe_tail].paddr;
+ if (paddr) {
+ /*
+ * There is a valid entry that needs processing.
+ */
+ node = cpe[cpe_tail].node;
+
+ ret = ia64_mca_cpe_move_page(paddr, node);
+ if (ret <= 0)
+ /*
+ * Even though the return status is negative,
+ * clear the entry. If the same address has
+ * another CPE it will be re-added to the list.
+ */
+ cpe[cpe_tail].paddr = 0;
+
+ }
+ if (++cpe_tail >= CE_HISTORY_LENGTH)
+ cpe_tail = 0;
+
+ } while (cpe_tail != cpe_head);
+ work_scheduled = 0;
+}
+
+static DECLARE_WORK(cpe_enable_work, ia64_mca_cpe_migrate);
+DEFINE_SPINLOCK(cpe_list_lock);
+
+/*
+ * cpe_setup_migrate
+ * Get the physical address out of the CPE record, add it
+ * to the list of addresses to migrate (if not already on),
+ * and schedule the back end worker task. This is called
+ * in interrupt context so cannot directly call the migration
+ * code.
+ *
+ * Inputs
+ * rec The CPE record
+ * Outputs
+ * 1 on Success, -1 on failure
+ */
+static int
+cpe_setup_migrate(void *rec)
+{
+ u64 paddr;
+ u16 node;
+ /* int head, tail; */
+ int i, ret;
+
+ if (!rec)
+ return -EINVAL;
+
+ get_physical_address(rec, &paddr, &node);
+ ret = validate_paddr_page(paddr);
+ if (ret < 0)
+ return -EINVAL;
+
+ if ((cpe_head != cpe_tail) || (cpe[cpe_head].paddr != 0))
+ /*
+ * List not empty
+ */
+ for (i = 0; i < CE_HISTORY_LENGTH; i++) {
+ if (PAGE_ALIGN(cpe[i].paddr) == PAGE_ALIGN(paddr))
+ return 1; /* already on the list */
+ }
+
+ if (!spin_trylock(&cpe_list_lock)) {
+ /*
+ * Someone else has the lock. To avoid spinning in interrupt
+ * handler context, bail.
+ */
+ return 1;
+ }
+
+ if (cpe[cpe_head].paddr == 0) {
+ cpe[cpe_head].node = node;
+ cpe[cpe_head].paddr = paddr;
+
+ if (++cpe_head >= CE_HISTORY_LENGTH)
+ cpe_head = 0;
+ }
+ spin_unlock(&cpe_list_lock);
+
+ if (!work_scheduled) {
+ work_scheduled = 1;
+ schedule_work(&cpe_enable_work);
+ }
+
+ return 1;
+}
+
+/*
+ * =============================================================================
+ */
+
+/*
+ * free_one_bad_page
+ * Free one page from the list of bad pages.
+ */
+static int
+free_one_bad_page(unsigned long paddr)
+{
+ LIST_HEAD(pagelist);
+ struct page *page, *page2, *target;
+
+ /*
+ * Verify page address
+ */
+ target = phys_to_page(paddr);
+ list_for_each_entry_safe(page, page2, &badpagelist, lru) {
+ if (page != target)
+ continue;
+
+ ClearPageMemError(page); /* Mark the page as good */
+ totalbad_pages--;
+ list_move_tail(&page->lru, &pagelist);
+ putback_lru_pages(&pagelist);
+ break;
+ }
+ return 0;
+}
+
+/*
+ * free_all_bad_pages
+ * Free all of the pages on the bad pages list.
+ */
+static int
+free_all_bad_pages(void)
+{
+ struct page *page, *page2;
+
+ list_for_each_entry_safe(page, page2, &badpagelist, lru) {
+ ClearPageMemError(page); /* Mark the page as good */
+ totalbad_pages--;
+ }
+ putback_lru_pages(&badpagelist);
+ return 0;
+}
+
+#define OPT_LEN 16
+
+static ssize_t
+badpage_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ char optstr[OPT_LEN];
+ unsigned long opt;
+ int len = OPT_LEN;
+ int err;
+
+ if (count < len)
+ len = count;
+
+ strlcpy(optstr, buf, len);
+
+ err = strict_strtoul(optstr, 16, &opt);
+ if (err)
+ return err;
+
+ if (opt == 0)
+ free_all_bad_pages();
+ else
+ free_one_bad_page(opt);
+
+ return count;
+}
+
+/*
+ * badpage_show
+ * Display the number, size, and addresses of all the pages on the
+ * bad page list.
+ *
+ * Note that sysfs provides buf of PAGE_SIZE length. bufend tracks
+ * the remaining space in buf to avoid overflowing.
+ */
+static ssize_t
+badpage_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+
+{
+ struct page *page, *page2;
+ int i = 0, cnt = 0;
+ char *bufend = buf + PAGE_SIZE;
+
+ cnt = snprintf(buf, bufend - (buf + cnt),
+ "Bad RAM: %d kB, %d pages marked bad\n"
+ "List of bad physical pages\n",
+ totalbad_pages << (PAGE_SHIFT - 10), totalbad_pages);
+
+ list_for_each_entry_safe(page, page2, &badpagelist, lru) {
+ if (bufend - (buf + cnt) < 20)
+ break; /* Avoid overflowing the buffer */
+ cnt += snprintf(buf + cnt, bufend - (buf + cnt),
+ " 0x%011lx", page_to_phys(page));
+ if (!(++i % 5))
+ cnt += snprintf(buf + cnt, bufend - (buf + cnt), "\n");
+ }
+ cnt += snprintf(buf + cnt, bufend - (buf + cnt), "\n");
+
+ return cnt;
+}
+
+static struct kobj_attribute badram_attr = {
+ .attr = {
+ .name = "badram",
+ .mode = S_IWUSR | S_IRUGO,
+ },
+ .show = badpage_show,
+ .store = badpage_store,
+};
+
+static int __init
+cpe_migrate_external_handler_init(void)
+{
+ int error;
+
+ error = sysfs_create_file(kernel_kobj, &badram_attr.attr);
+ if (error)
+ return -EINVAL;
+
+ /*
+ * register external ce handler
+ */
+ if (ia64_reg_CE_extension(cpe_setup_migrate)) {
+ printk(KERN_ERR "ia64_reg_CE_extension failed.\n");
+ return -EFAULT;
+ }
+ cpe_poll_enabled = cpe_polling_enabled;
+
+ printk(KERN_INFO "Registered badram Driver\n");
+ return 0;
+}
+
+static void __exit
+cpe_migrate_external_handler_exit(void)
+{
+ /* unregister external mca handlers */
+ ia64_unreg_CE_extension();
+
+ sysfs_remove_file(kernel_kobj, &badram_attr.attr);
+}
+
+module_init(cpe_migrate_external_handler_init);
+module_exit(cpe_migrate_external_handler_exit);
+
+module_param(cpe_polling_enabled, int, 0644);
+MODULE_PARM_DESC(cpe_polling_enabled,
+ "Enable polling with migration");
+
+MODULE_AUTHOR("Russ Anderson <rja@xxxxxxx>");
+MODULE_DESCRIPTION("ia64 Corrected Error page migration driver");
+MODULE_LICENSE("GPL");
Index: linus/arch/ia64/kernel/mca.c
===================================================================
--- linus.orig/arch/ia64/kernel/mca.c 2008-05-14 15:36:06.822294012 -0500
+++ linus/arch/ia64/kernel/mca.c 2008-05-15 12:59:05.938701796 -0500
@@ -68,6 +68,9 @@
*
* 2007-04-27 Russ Anderson <rja@xxxxxxx>
* Support multiple cpus going through OS_MCA in the same event.
+ *
+ * 2008-04-22 Russ Anderson <rja@xxxxxxx>
+ * Migrate data off pages with correctable memory errors.
*/
#include <linux/jiffies.h>
#include <linux/types.h>
@@ -163,7 +166,11 @@ static int cmc_polling_enabled = 1;
* but encounters problems retrieving CPE logs. This should only be
* necessary for debugging.
*/
-static int cpe_poll_enabled = 1;
+int cpe_poll_enabled = 1;
+EXPORT_SYMBOL(cpe_poll_enabled);
+
+LIST_HEAD(badpagelist);
+EXPORT_SYMBOL(badpagelist);

extern void salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe);

@@ -523,6 +530,28 @@ int mca_recover_range(unsigned long addr
}
EXPORT_SYMBOL_GPL(mca_recover_range);

+/* Function pointer to Corrected Error memory migration driver */
+int (*ia64_mca_ce_extension)(void *);
+
+int
+ia64_reg_CE_extension(int (*fn)(void *))
+{
+ if (ia64_mca_ce_extension)
+ return 1;
+
+ ia64_mca_ce_extension = fn;
+ return 0;
+}
+EXPORT_SYMBOL(ia64_reg_CE_extension);
+
+void
+ia64_unreg_CE_extension(void)
+{
+ if (ia64_mca_ce_extension)
+ ia64_mca_ce_extension = NULL;
+}
+EXPORT_SYMBOL(ia64_unreg_CE_extension);
+
#ifdef CONFIG_ACPI

int cpe_vector = -1;
@@ -534,6 +563,7 @@ ia64_mca_cpe_int_handler (int cpe_irq, v
static unsigned long cpe_history[CPE_HISTORY_LENGTH];
static int index;
static DEFINE_SPINLOCK(cpe_history_lock);
+ int recover;

IA64_MCA_DEBUG("%s: received interrupt vector = %#x on CPU %d\n",
__func__, cpe_irq, smp_processor_id());
@@ -580,6 +610,8 @@ ia64_mca_cpe_int_handler (int cpe_irq, v
out:
/* Get the CPE error record and log it */
ia64_mca_log_sal_error_record(SAL_INFO_TYPE_CPE);
+ recover = (ia64_mca_ce_extension && ia64_mca_ce_extension(
+ IA64_LOG_CURR_BUFFER(SAL_INFO_TYPE_CPE)));

return IRQ_HANDLED;
}
Index: linus/arch/ia64/Kconfig
===================================================================
--- linus.orig/arch/ia64/Kconfig 2008-05-14 15:36:06.826294509 -0500
+++ linus/arch/ia64/Kconfig 2008-05-15 12:59:05.962704753 -0500
@@ -456,6 +456,15 @@ config COMPAT_FOR_U64_ALIGNMENT
config IA64_MCA_RECOVERY
tristate "MCA recovery from errors other than TLB."

+config IA64_CPE_MIGRATE
+ tristate "Migrate data off pages with correctable errors"
+ default m
+ help
+ Migrate data off pages with correctable memory errors. Selecting
+ Y will build this functionality into the kernel. Selecting M will
+ build this functionality as a kernel loadable module. Installing
+ the module will turn on the functionality.
+
config PERFMON
bool "Performance monitor support"
help
Index: linus/include/asm-ia64/mca.h
===================================================================
--- linus.orig/include/asm-ia64/mca.h 2008-05-14 15:36:06.826294509 -0500
+++ linus/include/asm-ia64/mca.h 2008-05-15 12:59:05.986707709 -0500
@@ -137,6 +137,7 @@ extern unsigned long __per_cpu_mca[NR_CP

extern int cpe_vector;
extern int ia64_cpe_irq;
+extern int cpe_poll_enabled;
extern void ia64_mca_init(void);
extern void ia64_mca_cpu_init(void *);
extern void ia64_os_mca_dispatch(void);
@@ -150,9 +151,13 @@ extern void ia64_slave_init_handler(void
extern void ia64_mca_cmc_vector_setup(void);
extern int ia64_reg_MCA_extension(int (*fn)(void *, struct ia64_sal_os_state *));
extern void ia64_unreg_MCA_extension(void);
+extern int ia64_reg_CE_extension(int (*fn)(void *));
+extern void ia64_unreg_CE_extension(void);
extern u64 ia64_get_rnat(u64 *);
extern void ia64_mca_printk(const char * fmt, ...)
__attribute__ ((format (printf, 1, 2)));
+
+extern struct list_head badpagelist;

struct ia64_mca_notify_die {
struct ia64_sal_os_state *sos;
Index: linus/mm/migrate.c
===================================================================
--- linus.orig/mm/migrate.c 2008-05-15 12:59:04.978583534 -0500
+++ linus/mm/migrate.c 2008-05-15 12:59:06.006710173 -0500
@@ -36,6 +36,7 @@
#define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))

unsigned int totalbad_pages;
+EXPORT_SYMBOL(totalbad_pages);

/*
* Isolate one page from the LRU lists. If successful put it onto
@@ -66,6 +67,7 @@ int isolate_lru_page(struct page *page,
}
return ret;
}
+EXPORT_SYMBOL(isolate_lru_page);

/*
* migrate_prep() needs to be called before we start compiling a list of pages
@@ -83,6 +85,7 @@ int migrate_prep(void)

return 0;
}
+EXPORT_SYMBOL(migrate_prep);

static inline void move_to_lru(struct page *page)
{
@@ -119,6 +122,7 @@ int putback_lru_pages(struct list_head *
}
return count;
}
+EXPORT_SYMBOL(putback_lru_pages);

/*
* Restore a potential migration pte to a working pte entry
@@ -810,6 +814,7 @@ out:

return nr_failed + retry;
}
+EXPORT_SYMBOL(migrate_pages);

#ifdef CONFIG_NUMA
/*
Index: linus/include/asm-ia64/page.h
===================================================================
--- linus.orig/include/asm-ia64/page.h 2008-05-14 15:36:06.826294509 -0500
+++ linus/include/asm-ia64/page.h 2008-05-15 12:59:06.022712144 -0500
@@ -122,6 +122,7 @@ extern unsigned long max_low_pfn;
#endif

#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
+#define phys_to_page(kaddr) (pfn_to_page(kaddr >> PAGE_SHIFT))
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)

--
Russ Anderson, OS RAS/Partitioning Project Lead
SGI - Silicon Graphics Inc rja@xxxxxxx
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