From 7f52a526f64c69c913f0027fbf43821ff0b3a7d7 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 24 Apr 2014 18:00:18 +1000 Subject: [PATCH] powerpc/eeh: Allow to disable EEH The patch introduces bootarg "eeh=off" to disable EEH functinality. Also, it creates /sys/kerenl/debug/powerpc/eeh_enable to disable or enable EEH functionality. By default, we have the functionality enabled. For PowerNV platform, we will restore to have the conventional mechanism of clearing frozen PE during PCI config access if we're going to disable EEH functionality. Conversely, we will rely on EEH for error recovery. The patch also fixes the issue that we missed to cover the case of disabled EEH functionality in function ioda_eeh_event(). Those events driven by interrupt should be cleared to avoid endless reporting. Signed-off-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/eeh.c | 47 ++++++++++++++++++++++- arch/powerpc/platforms/powernv/eeh-ioda.c | 29 +++++++++++--- arch/powerpc/platforms/powernv/pci.h | 1 + 3 files changed, 70 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 06d2b7c6b661..1e409a2ff88b 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -22,6 +22,7 @@ */ #include +#include #include #include #include @@ -132,6 +133,15 @@ static struct eeh_stats eeh_stats; #define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE) +static int __init eeh_setup(char *str) +{ + if (!strcmp(str, "off")) + eeh_subsystem_flags |= EEH_FORCE_DISABLED; + + return 1; +} +__setup("eeh=", eeh_setup); + /** * eeh_gather_pci_data - Copy assorted PCI config space registers to buff * @edev: device to report data for @@ -1117,10 +1127,45 @@ static const struct file_operations proc_eeh_operations = { .release = single_release, }; +#ifdef CONFIG_DEBUG_FS +static int eeh_enable_dbgfs_set(void *data, u64 val) +{ + if (val) + eeh_subsystem_flags &= ~EEH_FORCE_DISABLED; + else + eeh_subsystem_flags |= EEH_FORCE_DISABLED; + + /* Notify the backend */ + if (eeh_ops->post_init) + eeh_ops->post_init(); + + return 0; +} + +static int eeh_enable_dbgfs_get(void *data, u64 *val) +{ + if (eeh_enabled()) + *val = 0x1ul; + else + *val = 0x0ul; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get, + eeh_enable_dbgfs_set, "0x%llx\n"); +#endif + static int __init eeh_init_proc(void) { - if (machine_is(pseries) || machine_is(powernv)) + if (machine_is(pseries) || machine_is(powernv)) { proc_create("powerpc/eeh", 0, NULL, &proc_eeh_operations); +#ifdef CONFIG_DEBUG_FS + debugfs_create_file("eeh_enable", 0600, + powerpc_debugfs_root, NULL, + &eeh_enable_dbgfs_ops); +#endif + } + return 0; } __initcall(eeh_init_proc); diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c index 6bdae8d84463..35ec394f784f 100644 --- a/arch/powerpc/platforms/powernv/eeh-ioda.c +++ b/arch/powerpc/platforms/powernv/eeh-ioda.c @@ -42,11 +42,19 @@ static int ioda_eeh_event(struct notifier_block *nb, { uint64_t changed_evts = (uint64_t)change; - /* We simply send special EEH event */ - if ((changed_evts & OPAL_EVENT_PCI_ERROR) && - (events & OPAL_EVENT_PCI_ERROR) && - eeh_enabled()) + /* + * We simply send special EEH event if EEH has + * been enabled, or clear pending events in + * case that we enable EEH soon + */ + if (!(changed_evts & OPAL_EVENT_PCI_ERROR) || + !(events & OPAL_EVENT_PCI_ERROR)) + return 0; + + if (eeh_enabled()) eeh_send_failure_event(NULL); + else + opal_notifier_update_evt(OPAL_EVENT_PCI_ERROR, 0x0ul); return 0; } @@ -141,7 +149,9 @@ static int ioda_eeh_post_init(struct pci_controller *hose) } #ifdef CONFIG_DEBUG_FS - if (phb->dbgfs) { + if (!phb->has_dbgfs && phb->dbgfs) { + phb->has_dbgfs = 1; + debugfs_create_file("err_injct_outbound", 0600, phb->dbgfs, hose, &ioda_eeh_outb_dbgfs_ops); @@ -154,7 +164,14 @@ static int ioda_eeh_post_init(struct pci_controller *hose) } #endif - phb->flags |= PNV_PHB_FLAG_EEH; + /* If EEH is enabled, we're going to rely on that. + * Otherwise, we restore to conventional mechanism + * to clear frozen PE during PCI config access. + */ + if (eeh_enabled()) + phb->flags |= PNV_PHB_FLAG_EEH; + else + phb->flags &= ~PNV_PHB_FLAG_EEH; return 0; } diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h index 94e3495b7f2b..39ec6978e809 100644 --- a/arch/powerpc/platforms/powernv/pci.h +++ b/arch/powerpc/platforms/powernv/pci.h @@ -101,6 +101,7 @@ struct pnv_phb { #endif #ifdef CONFIG_DEBUG_FS + int has_dbgfs; struct dentry *dbgfs; #endif -- 2.39.2