1#!/bin/sh 2# SPDX-License-Identifier: GPL-2.0-only 3 4export KSELFTESTS_SKIP=4 5 6log() { 7 echo >/dev/stderr $* 8} 9 10pe_ok() { 11 local dev="$1" 12 local path="/sys/bus/pci/devices/$dev/eeh_pe_state" 13 14 # if a driver doesn't support the error handling callbacks then the 15 # device is recovered by removing and re-probing it. This causes the 16 # sysfs directory to disappear so read the PE state once and squash 17 # any potential error messages 18 local eeh_state="$(cat $path 2>/dev/null)" 19 if [ -z "$eeh_state" ]; then 20 return 1; 21 fi 22 23 local fw_state="$(echo $eeh_state | cut -d' ' -f1)" 24 local sw_state="$(echo $eeh_state | cut -d' ' -f2)" 25 26 # If EEH_PE_ISOLATED or EEH_PE_RECOVERING are set then the PE is in an 27 # error state or being recovered. Either way, not ok. 28 if [ "$((sw_state & 0x3))" -ne 0 ] ; then 29 return 1 30 fi 31 32 # A functioning PE should have the EEH_STATE_MMIO_ACTIVE and 33 # EEH_STATE_DMA_ACTIVE flags set. For some goddamn stupid reason 34 # the platform backends set these when the PE is in reset. The 35 # RECOVERING check above should stop any false positives though. 36 if [ "$((fw_state & 0x18))" -ne "$((0x18))" ] ; then 37 return 1 38 fi 39 40 return 0; 41} 42 43eeh_supported() { 44 test -e /proc/powerpc/eeh && \ 45 grep -q 'EEH Subsystem is enabled' /proc/powerpc/eeh 46} 47 48eeh_test_prep() { 49 if ! eeh_supported ; then 50 echo "EEH not supported on this system, skipping" 51 exit $KSELFTESTS_SKIP; 52 fi 53 54 if [ ! -e "/sys/kernel/debug/powerpc/eeh_dev_check" ] && \ 55 [ ! -e "/sys/kernel/debug/powerpc/eeh_dev_break" ] ; then 56 log "debugfs EEH testing files are missing. Is debugfs mounted?" 57 exit $KSELFTESTS_SKIP; 58 fi 59 60 # Bump the max freeze count to something absurd so we don't 61 # trip over it while breaking things. 62 echo 5000 > /sys/kernel/debug/powerpc/eeh_max_freezes 63} 64 65eeh_can_break() { 66 # skip bridges since we can't recover them (yet...) 67 if [ -e "/sys/bus/pci/devices/$dev/pci_bus" ] ; then 68 log "$dev, Skipped: bridge" 69 return 1; 70 fi 71 72 # The ahci driver doesn't support error recovery. If the ahci device 73 # happens to be hosting the root filesystem, and then we go and break 74 # it the system will generally go down. We should probably fix that 75 # at some point 76 if [ "ahci" = "$(basename $(realpath /sys/bus/pci/devices/$dev/driver))" ] ; then 77 log "$dev, Skipped: ahci doesn't support recovery" 78 return 1; 79 fi 80 81 # Don't inject errosr into an already-frozen PE. This happens with 82 # PEs that contain multiple PCI devices (e.g. multi-function cards) 83 # and injecting new errors during the recovery process will probably 84 # result in the recovery failing and the device being marked as 85 # failed. 86 if ! pe_ok $dev ; then 87 log "$dev, Skipped: Bad initial PE state" 88 return 1; 89 fi 90 91 return 0 92} 93 94eeh_one_dev() { 95 local dev="$1" 96 97 # Using this function from the command line is sometimes useful for 98 # testing so check that the argument is a well-formed sysfs device 99 # name. 100 if ! test -e /sys/bus/pci/devices/$dev/ ; then 101 log "Error: '$dev' must be a sysfs device name (DDDD:BB:DD.F)" 102 return 1; 103 fi 104 105 # Break it 106 echo $dev >/sys/kernel/debug/powerpc/eeh_dev_break 107 108 # Force an EEH device check. If the kernel has already 109 # noticed the EEH (due to a driver poll or whatever), this 110 # is a no-op. 111 echo $dev >/sys/kernel/debug/powerpc/eeh_dev_check 112 113 # Default to a 60s timeout when waiting for a device to recover. This 114 # is an arbitrary default which can be overridden by setting the 115 # EEH_MAX_WAIT environmental variable when required. 116 117 # The current record holder for longest recovery time is: 118 # "Adaptec Series 8 12G SAS/PCIe 3" at 39 seconds 119 max_wait=${EEH_MAX_WAIT:=60} 120 121 for i in `seq 0 ${max_wait}` ; do 122 if pe_ok $dev ; then 123 break; 124 fi 125 log "$dev, waited $i/${max_wait}" 126 sleep 1 127 done 128 129 if ! pe_ok $dev ; then 130 log "$dev, Failed to recover!" 131 return 1; 132 fi 133 134 log "$dev, Recovered after $i seconds" 135 return 0; 136} 137 138