linux/arch/powerpc
Nicholas Piggin ac61c11566 powerpc: Fix smp_send_stop NMI IPI handling
The NMI IPI handler for a receiving CPU increments nmi_ipi_busy_count
over the handler function call, which causes later smp_send_nmi_ipi()
callers to spin until the call is finished.

The stop_this_cpu() function never returns, so the busy count is never
decremeted, which can cause the system to hang in some cases. For
example panic() will call smp_send_stop() early on which calls
stop_this_cpu() on other CPUs, then later in the reboot path,
pnv_restart() will call smp_send_stop() again, which hangs.

Fix this by adding a special case to the stop_this_cpu() handler to
decrement the busy count, because it will never return.

Now that the NMI/non-NMI versions of stop_this_cpu() are different,
split them out into separate functions rather than doing #ifdef tricks
to share the body between the two functions.

Fixes: 6bed323762 ("powerpc: use NMI IPI for smp_send_stop")
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Split out the functions, tweak change log a bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-25 20:38:08 +10:00
..
boot powerpc updates for 4.17 2018-04-07 12:08:19 -07:00
configs scsi: remove the fdomain and fdomain_cs drivers 2018-03-19 22:54:47 -04:00
crypto crypto: hash - annotate algorithms taking optional key 2018-01-12 23:03:35 +11:00
include powerpc/powernv/npu: Prevent overwriting of pnv_npu2_init_contex() callback parameters 2018-04-24 09:46:57 +10:00
kernel powerpc: Fix smp_send_stop NMI IPI handling 2018-04-25 20:38:08 +10:00
kvm powerpc fixes for 4.17 #2 2018-04-15 11:57:12 -07:00
lib powerpc/lib: Fix off-by-one in alternate feature patching 2018-04-17 00:37:48 +10:00
math-emu
mm powerpc/mm: Flush cache on memory hot(un)plug 2018-04-24 09:46:56 +10:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-05 11:29:24 -08:00
oprofile powerpc: Use sizeof(*foo) rather than sizeof(struct foo) 2018-03-20 16:47:53 +11:00
perf powerpc updates for 4.17 2018-04-07 12:08:19 -07:00
platforms rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops 2018-04-25 13:24:13 +10:00
purgatory
sysdev powerpc/xive: Fix trying to "push" an already active pool VP 2018-04-19 00:49:45 +10:00
tools
xmon Merge branch 'topic/paca' into next 2018-03-31 09:09:36 +11:00
Kconfig kexec_file: make use of purgatory optional 2018-04-13 17:10:27 -07:00
Kconfig.debug powerpc: Add new kconfig CONFIG_PPC_IRQ_SOFT_MASK_DEBUG 2018-01-19 22:37:03 +11:00
Makefile powerpc/64s: Add POWER9 CPU type selection 2018-04-01 22:15:32 +10:00
Makefile.postlink