linux/arch
Stephen Warren 19ab428f4b ARM: 7759/1: decouple CPU offlining from reboot/shutdown
Add comments to machine_shutdown()/halt()/power_off()/restart() that
describe their purpose and/or requirements re: CPUs being active/not.

In machine_shutdown(), replace the call to smp_send_stop() with a call to
disable_nonboot_cpus(). This completely disables all but one CPU, thus
satisfying the requirement that only a single CPU be active for kexec.
Adjust Kconfig dependencies for this change.

In machine_halt()/power_off()/restart(), call smp_send_stop() directly,
rather than via machine_shutdown(); these functions don't need to
completely de-activate all CPUs using hotplug, but rather just quiesce
them.

Remove smp_kill_cpus(), and its call from smp_send_stop().
smp_kill_cpus() was indirectly calling smp_ops.cpu_kill() without calling
smp_ops.cpu_die() on the target CPUs first. At least some implementations
of smp_ops had issues with this; it caused cpu_kill() to hang on Tegra,
for example. Since smp_send_stop() is only used for shutdown, halt, and
power-off, there is no need to attempt any kind of CPU hotplug here.

Adjust Kconfig to reflect that machine_shutdown() (and hence kexec)
relies upon disable_nonboot_cpus(). However, this alone doesn't guarantee
that hotplug will work, or even that hotplug is implemented for a
particular piece of HW that a multi-platform zImage runs on. Hence, add
error-checking to machine_kexec() to determine whether it did work.

Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by:  Zhangfei Gao <zhangfei.gao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-06-17 21:35:25 +01:00
..
alpha Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
arc ARC: lazy dcache flush broke gdb in non-aliasing configs 2013-05-25 14:15:55 +05:30
arm ARM: 7759/1: decouple CPU offlining from reboot/shutdown 2013-06-17 21:35:25 +01:00
arm64 arm64: don't kill the kernel on a bad esr from el0 2013-05-31 16:04:51 +01:00
avr32 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32 2013-05-22 18:06:57 -07:00
blackfin blackfin updates for Linux 3.10 2013-05-10 07:21:16 -07:00
c6x dump_stack: unify debug information printed by show_regs() 2013-04-30 17:04:02 -07:00
cris - Lots of cleanups from Artem, including deletion of some obsolete drivers 2013-05-09 10:15:46 -07:00
frv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00
h8300 We get rid of the general module prefix confusion with a binary config option, 2013-05-05 10:58:06 -07:00
hexagon Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
ia64 Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
m32r Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00
m68k m68k: Update defconfigs for v3.9 2013-05-28 10:22:06 +02:00
metag Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
microblaze microblaze: Reversed logic in futex cmpxchg 2013-05-27 12:29:35 +02:00
mips USB fixes for 3.10-rc2 2013-05-23 09:23:32 -07:00
mn10300 MN10300: Need pci_iomap() and __pci_ioport_map() defining 2013-05-30 13:38:48 +09:00
openrisc Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
parisc parisc: kernel: using strlcpy() instead of strcpy() 2013-06-01 14:29:01 +02:00
powerpc powerpc/cputable: Fix typo on P7+ cputable entry 2013-06-01 09:30:03 +10:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2013-05-21 09:36:46 -07:00
score score: remove redundant kcore_list entries 2013-05-25 10:27:27 -07:00
sh Removal of GENERIC_GPIO for v3.10 2013-05-09 09:59:16 -07:00
sparc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-05-10 09:21:05 -07:00
tile Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2013-05-09 14:34:58 -07:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-07 15:14:53 -07:00
unicore32 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-05-10 09:21:05 -07:00
x86 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-31 09:44:10 +09:00
xtensa Xtensa patchset for v3.10-rc1 2013-05-09 14:38:16 -07:00
.gitignore
Kconfig Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-15 14:04:00 -07:00