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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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![]() Calling irq_find_mapping from outside a irq_{enter,exit} section is unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled: If coming from the idle state, the rcu_read_lock call in irq_find_mapping will generate an unpleasant warning: <quote> =============================== [ INFO: suspicious RCU usage. ] 3.16.0-rc1+ #135 Not tainted ------------------------------- include/linux/rcupdate.h:871 rcu_read_lock() used illegally while idle! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 1 lock held by swapper/0/0: #0: (rcu_read_lock){......}, at: [<ffffffc00010206c>] irq_find_mapping+0x4c/0x198 </quote> As this issue is fairly widespread and involves at least three different architectures, a possible solution is to add a new handle_domain_irq entry point into the generic IRQ code that the interrupt controller code can call. This new function takes an irq_domain, and calls into irq_find_domain inside the irq_{enter,exit} block. An additional "lookup" parameter is used to allow non-domain architecture code to be replaced by this as well. Interrupt controllers can then be updated to use the new mechanism. This code is sitting behind a new CONFIG_HANDLE_DOMAIN_IRQ, as not all architectures implement set_irq_regs (yes, mn10300, I'm looking at you...). Reported-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/1409047421-27649-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Jason Cooper <jason@lakedaemon.net> |
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.. | ||
bpf | ||
debug | ||
events | ||
gcov | ||
irq | ||
locking | ||
power | ||
printk | ||
rcu | ||
sched | ||
time | ||
trace | ||
.gitignore | ||
acct.c | ||
async.c | ||
audit_tree.c | ||
audit_watch.c | ||
audit.c | ||
audit.h | ||
auditfilter.c | ||
auditsc.c | ||
backtracetest.c | ||
bounds.c | ||
capability.c | ||
cgroup_freezer.c | ||
cgroup.c | ||
compat.c | ||
configs.c | ||
context_tracking.c | ||
cpu_pm.c | ||
cpu.c | ||
cpuset.c | ||
crash_dump.c | ||
cred.c | ||
delayacct.c | ||
dma.c | ||
elfcore.c | ||
exec_domain.c | ||
exit.c | ||
extable.c | ||
fork.c | ||
freezer.c | ||
futex_compat.c | ||
futex.c | ||
groups.c | ||
hung_task.c | ||
irq_work.c | ||
jump_label.c | ||
kallsyms.c | ||
kcmp.c | ||
Kconfig.freezer | ||
Kconfig.hz | ||
Kconfig.locks | ||
Kconfig.preempt | ||
kexec.c | ||
kmod.c | ||
kprobes.c | ||
ksysfs.c | ||
kthread.c | ||
latencytop.c | ||
Makefile | ||
module_signing.c | ||
module-internal.h | ||
module.c | ||
notifier.c | ||
nsproxy.c | ||
padata.c | ||
panic.c | ||
params.c | ||
pid_namespace.c | ||
pid.c | ||
profile.c | ||
ptrace.c | ||
range.c | ||
reboot.c | ||
relay.c | ||
res_counter.c | ||
resource.c | ||
seccomp.c | ||
signal.c | ||
smp.c | ||
smpboot.c | ||
smpboot.h | ||
softirq.c | ||
stacktrace.c | ||
stop_machine.c | ||
sys_ni.c | ||
sys.c | ||
sysctl_binary.c | ||
sysctl.c | ||
system_certificates.S | ||
system_keyring.c | ||
task_work.c | ||
taskstats.c | ||
test_kprobes.c | ||
torture.c | ||
tracepoint.c | ||
tsacct.c | ||
uid16.c | ||
up.c | ||
user_namespace.c | ||
user-return-notifier.c | ||
user.c | ||
utsname_sysctl.c | ||
utsname.c | ||
watchdog.c | ||
workqueue_internal.h | ||
workqueue.c |