linux/arch/arm64
James Morse 5c492c3f52 arm64: smp: Add function to determine if cpus are stuck in the kernel
kernel/smp.c has a fancy counter that keeps track of the number of CPUs
it marked as not-present and left in cpu_park_loop(). If there are any
CPUs spinning in here, features like kexec or hibernate may release them
by overwriting this memory.

This problem also occurs on machines using spin-tables to release
secondary cores.
After commit 44dbcc93ab ("arm64: Fix behavior of maxcpus=N")
we bring all known cpus into the secondary holding pen, meaning this
memory can't be re-used by kexec or hibernate.

Add a function cpus_are_stuck_in_kernel() to determine if either of these
cases have occurred.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-06-22 15:48:09 +01:00
..
boot arm64: dts: drop "arm,amba-bus" in favor of "simple-bus" part 2 2016-06-03 12:13:15 -07:00
configs Merge git://www.linux-watchdog.org/linux-watchdog 2016-05-25 10:19:17 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-03-17 11:22:54 -07:00
include arm64: smp: Add function to determine if cpus are stuck in the kernel 2016-06-22 15:48:09 +01:00
kernel arm64: smp: Add function to determine if cpus are stuck in the kernel 2016-06-22 15:48:09 +01:00
kvm arm64: KVM: vgic-v3: Relax synchronization when SRE==1 2016-05-31 16:12:17 +02:00
lib arm64 updates for 4.6: 2016-03-17 20:03:47 -07:00
mm arm64: mm: remove page_mapping check in __sync_icache_dcache 2016-06-21 20:10:18 +01:00
net bpf: arm64: remove callee-save registers use for tmp registers 2016-05-17 14:03:33 -04:00
xen xen/arm: introduce HYPERVISOR_platform_op on arm and arm64 2015-12-21 14:40:56 +00:00
Kconfig Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-06-03 16:12:35 -07:00
Kconfig.debug arm64: enable CONFIG_SET_MODULE_RONX by default 2016-05-31 14:23:29 +01:00
Kconfig.platforms ARM: SoC 64-bit changes for v4.7 2016-05-18 12:43:08 -07:00
Makefile arm64: fix boot image dependencies to not generate invalid images 2016-06-21 20:10:18 +01:00