linux-dev/arch/powerpc/kernel/eeh_event.c, branch linus/master

powerpc: fix typos in comments

2022-05-05T12:12:44Z

Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Reviewed-by: Joel Stanley Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr

powerpc/eeh: Fix build with STACKTRACE=n

2019-09-13T14:01:14Z

The build breaks when STACKTRACE=n, eg. skiroot_defconfig: arch/powerpc/kernel/eeh_event.c:124:23: error: implicit declaration of function 'stack_trace_save' Fix it with some ifdefs for now. Fixes: 25baf3d81614 ("powerpc/eeh: Defer printing stack trace") Signed-off-by: Michael Ellerman

powerpc/eeh: Defer printing stack trace

2019-09-05T04:22:38Z

Currently we print a stack trace in the event handler to help with debugging EEH issues. In the case of suprise hot-unplug this is unneeded, so we want to prevent printing the stack trace unless we know it's due to an actual device error. To accomplish this, we can save a stack trace at the point of detection and only print it once the EEH recovery handler has determined the freeze was due to an actual error. Since the whole point of this is to prevent spurious EEH output we also move a few prints out of the detection thread, or mark them as pr_debug so anyone interested can get output from the eeh_check_dev_failure() if they want. Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190903101605.2890-6-oohall@gmail.com

powerpc/eeh: Clean up EEH PEs after recovery finishes

2019-09-05T04:22:37Z

When the last device in an eeh_pe is removed the eeh_pe structure itself (and any empty parents) are freed since they are no longer needed. This results in a crash when a hotplug driver is involved since the following may occur: 1. Device is suprise removed. 2. Driver performs an MMIO, which fails and queues and eeh_event. 3. Hotplug driver receives a hotplug interrupt and removes any pci_devs that were under the slot. 4. pci_dev is torn down and the eeh_pe is freed. 5. The EEH event handler thread processes the eeh_event and crashes since the eeh_pe pointer in the eeh_event structure is no longer valid. Crashing is generally considered poor form. Instead of doing that use the fact PEs are marked as EEH_PE_INVALID to keep them around until the end of the recovery cycle, at which point we can safely prune any empty PEs. Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190903101605.2890-2-oohall@gmail.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc/eeh: Add eeh_force_recover to debugfs

2019-02-21T13:10:15Z

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

powerpc/eeh: Allow disabling recovery

2019-02-21T13:10:14Z

Currently when we detect an error we automatically invoke the EEH recovery handler. This can be annoying when debugging EEH problems, or when working on EEH itself so this patch adds a debugfs knob that will prevent a recovery event from being queued up when an issue is detected. Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman

powerpc: eeh_event: convert semaphore to completion

2018-12-20T11:21:20Z

For this use case, completions and semaphores are equivalent, but semaphores are an awkward interface that should generally be avoided, so use the completion instead. Signed-off-by: Arnd Bergmann Signed-off-by: Michael Ellerman

powerpc/eeh: Manage EEH_PE_RECOVERING inside eeh_handle_normal_event()

2018-03-27T12:44:58Z

Currently the EEH_PE_RECOVERING flag for a PE is managed by both the caller and callee of eeh_handle_normal_event() (among other places not considered here). This is complicated by the fact that the PE may or may not have been invalidated by the call. So move the callee's handling into eeh_handle_normal_event(), which clarifies it and allows the return type to be changed to void (because it no longer needs to indicate at the PE has been invalidated). This should not change behaviour except in eeh_event_handler() where it was previously possible to cause eeh_pe_state_clear() to be called on an invalid PE, which is now avoided. Signed-off-by: Sam Bobroff Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman

powerpc/eeh: Remove eeh_handle_event()

2018-03-27T12:44:57Z

The function eeh_handle_event(pe) does nothing other than switching between calling eeh_handle_normal_event(pe) and eeh_handle_special_event(). However it is only called in two places, one where pe can't be NULL and the other where it must be NULL (see eeh_event_handler()) so it does nothing but obscure the flow of control. So, remove it. Signed-off-by: Sam Bobroff Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman