Michael Ellerman c6baa077b7 powerpc/powernv: Make opal_event_shutdown() callable from IRQ context ... In opal_event_shutdown() we free all the IRQs hanging off the opal_event_irqchip. However it's not safe to do so if we're called from IRQ context, because free_irq() wants to synchronise versus IRQ context. This can lead to warnings and a stuck system. For example from sysrq-b: Trying to free IRQ 17 from IRQ context! ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/irq/manage.c:1461 __free_irq+0x398/0x8d0 ... NIP __free_irq+0x398/0x8d0 LR __free_irq+0x394/0x8d0 Call Trace: __free_irq+0x394/0x8d0 (unreliable) free_irq+0xa4/0x140 opal_event_shutdown+0x128/0x180 opal_shutdown+0x1c/0xb0 pnv_shutdown+0x20/0x40 machine_restart+0x38/0x90 emergency_restart+0x28/0x40 sysrq_handle_reboot+0x24/0x40 __handle_sysrq+0x198/0x590 hvc_poll+0x48c/0x8c0 hvc_handle_interrupt+0x1c/0x50 __handle_irq_event_percpu+0xe8/0x6e0 handle_irq_event_percpu+0x34/0xe0 handle_irq_event+0xc4/0x210 handle_level_irq+0x250/0x770 generic_handle_irq+0x5c/0xa0 opal_handle_events+0x11c/0x240 opal_interrupt+0x38/0x50 __handle_irq_event_percpu+0xe8/0x6e0 handle_irq_event_percpu+0x34/0xe0 handle_irq_event+0xc4/0x210 handle_fasteoi_irq+0x174/0xa10 generic_handle_irq+0x5c/0xa0 __do_irq+0xbc/0x4e0 call_do_irq+0x14/0x24 do_IRQ+0x18c/0x540 hardware_interrupt_common+0x158/0x180 We can avoid that by using disable_irq_nosync() rather than free_irq(). Although it doesn't fully free the IRQ, it should be sufficient when we're shutting down, particularly in an emergency. Add an in_interrupt() check and use free_irq() when we're shutting down normally. It's probably OK to use disable_irq_nosync() in that case too, but for now it's safer to leave that behaviour as-is. Fixes: 9f0fd0499d ("powerpc/powernv: Add a virtual irqchip for opal events") Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>		2017-10-06 20:03:08 +11:00
..
boot	powerpc: conditionally compile platform-specific serial drivers	2017-08-31 14:26:48 +10:00
configs	powerpc/configs: Add Skiroot defconfig	2017-10-04 22:26:46 +11:00
crypto	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2017-05-02 15:53:46 -07:00
include	powerpc/kprobes: Clean up jprobe detection in livepatch handler	2017-10-04 23:42:17 +11:00
kernel	powerpc/jprobes: Validate break handler invocation as being due to a jprobe_return()	2017-10-05 16:12:48 +11:00
kvm	kvm,powerpc: Serialize wq active checks in ops->vcpu_kick	2017-09-15 16:57:13 +02:00
lib	powerpc/lib/sstep: Fix fixed-point shift instructions that set CA32	2017-10-04 11:28:04 +11:00
math-emu	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
mm	cxl: Enable global TLBIs for cxl contexts	2017-09-28 17:09:16 +10:00
net	powerpc updates for 4.14	2017-09-07 10:15:40 -07:00
oprofile	powerpc/oprofile: Use setup_timer() helper	2017-10-04 11:28:01 +11:00
perf	powerpc/sysrq: Fix oops whem ppmu is not registered	2017-09-20 13:30:09 +10:00
platforms	powerpc/powernv: Make opal_event_shutdown() callable from IRQ context	2017-10-06 20:03:08 +11:00
purgatory	powerpc/asm: Convert .llong directives to .8byte	2017-08-31 14:26:47 +10:00
sysdev	treewide: make "nr_cpu_ids" unsigned	2017-09-08 18:26:48 -07:00
tools	powerpc/64: Tool to check head sections location sanity	2017-05-30 14:59:51 +10:00
xmon	powerpc/xmon: Avoid tripping SMP hardlockup watchdog	2017-10-04 11:26:23 +11:00
Kconfig	powerpc updates for 4.14	2017-09-07 10:15:40 -07:00
Kconfig.debug	powerpc/xmon: Enable disassembly files (compilation changes)	2017-02-15 20:02:42 +11:00
Makefile	Merge branch 'fixes' into next	2017-08-23 22:20:10 +10:00
Makefile.postlink	powerpc/64: Tool to check head sections location sanity	2017-05-30 14:59:51 +10:00