From 954bd99435b8ba99e86665d6a2ec1baa1d128325 Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Fri, 15 Feb 2019 11:48:17 +1100 Subject: [PATCH] powerpc/eeh: Add eeh_force_recover to debugfs This patch adds a debugfs interface to force scheduling a recovery event. This can be used to recover a specific PE or schedule a "special" recovery even that checks for errors at the PHB level. To force a recovery of a normal PE, use: echo '<#pe>:<#phb>' > /sys/kernel/debug/powerpc/eeh_force_recover To force a scan for broken PHBs: echo 'hwcheck' > /sys/kernel/debug/powerpc/eeh_force_recover Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/eeh_event.h | 1 + arch/powerpc/kernel/eeh.c | 59 ++++++++++++++++++++++++++++ arch/powerpc/kernel/eeh_event.c | 25 +++++++----- 3 files changed, 75 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/include/asm/eeh_event.h b/arch/powerpc/include/asm/eeh_event.h index 9884e872686f..6d0412b846ac 100644 --- a/arch/powerpc/include/asm/eeh_event.h +++ b/arch/powerpc/include/asm/eeh_event.h @@ -33,6 +33,7 @@ struct eeh_event { int eeh_event_init(void); int eeh_send_failure_event(struct eeh_pe *pe); +int __eeh_send_failure_event(struct eeh_pe *pe); void eeh_remove_event(struct eeh_pe *pe, bool force); void eeh_handle_normal_event(struct eeh_pe *pe); void eeh_handle_special_event(void); diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 0996f22b2612..289c0b37d845 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -1838,6 +1838,62 @@ static int eeh_enable_dbgfs_get(void *data, u64 *val) DEFINE_DEBUGFS_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get, eeh_enable_dbgfs_set, "0x%llx\n"); + +static ssize_t eeh_force_recover_write(struct file *filp, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct pci_controller *hose; + uint32_t phbid, pe_no; + struct eeh_pe *pe; + char buf[20]; + int ret; + + ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count); + if (!ret) + return -EFAULT; + + /* + * When PE is NULL the event is a "special" event. Rather than + * recovering a specific PE it forces the EEH core to scan for failed + * PHBs and recovers each. This needs to be done before any device + * recoveries can occur. + */ + if (!strncmp(buf, "hwcheck", 7)) { + __eeh_send_failure_event(NULL); + return count; + } + + ret = sscanf(buf, "%x:%x", &phbid, &pe_no); + if (ret != 2) + return -EINVAL; + + hose = pci_find_controller_for_domain(phbid); + if (!hose) + return -ENODEV; + + /* Retrieve PE */ + pe = eeh_pe_get(hose, pe_no, 0); + if (!pe) + return -ENODEV; + + /* + * We don't do any state checking here since the detection + * process is async to the recovery process. The recovery + * thread *should* not break even if we schedule a recovery + * from an odd state (e.g. PE removed, or recovery of a + * non-isolated PE) + */ + __eeh_send_failure_event(pe); + + return ret < 0 ? ret : count; +} + +static const struct file_operations eeh_force_recover_fops = { + .open = simple_open, + .llseek = no_llseek, + .write = eeh_force_recover_write, +}; #endif static int __init eeh_init_proc(void) @@ -1853,6 +1909,9 @@ static int __init eeh_init_proc(void) debugfs_create_bool("eeh_disable_recovery", 0600, powerpc_debugfs_root, &eeh_debugfs_no_recover); + debugfs_create_file_unsafe("eeh_force_recover", 0600, + powerpc_debugfs_root, NULL, + &eeh_force_recover_fops); eeh_cache_debugfs_init(); #endif } diff --git a/arch/powerpc/kernel/eeh_event.c b/arch/powerpc/kernel/eeh_event.c index 19837798bb1d..539aca055d70 100644 --- a/arch/powerpc/kernel/eeh_event.c +++ b/arch/powerpc/kernel/eeh_event.c @@ -121,20 +121,11 @@ int eeh_event_init(void) * the actual event will be delivered in a normal context * (from a workqueue). */ -int eeh_send_failure_event(struct eeh_pe *pe) +int __eeh_send_failure_event(struct eeh_pe *pe) { unsigned long flags; struct eeh_event *event; - /* - * If we've manually supressed recovery events via debugfs - * then just drop it on the floor. - */ - if (eeh_debugfs_no_recover) { - pr_err("EEH: Event dropped due to no_recover setting\n"); - return 0; - } - event = kzalloc(sizeof(*event), GFP_ATOMIC); if (!event) { pr_err("EEH: out of memory, event not handled\n"); @@ -153,6 +144,20 @@ int eeh_send_failure_event(struct eeh_pe *pe) return 0; } +int eeh_send_failure_event(struct eeh_pe *pe) +{ + /* + * If we've manually supressed recovery events via debugfs + * then just drop it on the floor. + */ + if (eeh_debugfs_no_recover) { + pr_err("EEH: Event dropped due to no_recover setting\n"); + return 0; + } + + return __eeh_send_failure_event(pe); +} + /** * eeh_remove_event - Remove EEH event from the queue * @pe: Event binding to the PE