https://github.com/torvalds/linux
Revision 19ab428f4b7988ef3ac727c680efc193ef53ce14 authored by Stephen Warren on 14 June 2013, 15:14:14 UTC, committed by Russell King on 17 June 2013, 20:35:25 UTC
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>
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Tip revision: 19ab428f4b7988ef3ac727c680efc193ef53ce14 authored by Stephen Warren on 14 June 2013, 15:14:14 UTC
ARM: 7759/1: decouple CPU offlining from reboot/shutdown
ARM: 7759/1: decouple CPU offlining from reboot/shutdown
Tip revision: 19ab428
File | Mode | Size |
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Documentation | ||
arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 1.1 KB |
.mailmap | -rw-r--r-- | 4.4 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 93.1 KB |
Kbuild | -rw-r--r-- | 2.5 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 248.8 KB |
Makefile | -rw-r--r-- | 47.3 KB |
README | -rw-r--r-- | 18.3 KB |
REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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