Hi Will, On Tue, Jan 10, 2017 at 11:32:48AM +0000, Will Deacon wrote: > On Wed, Dec 28, 2016 at 01:36:01PM +0900, AKASHI Takahiro wrote: > > Primary kernel calls machine_crash_shutdown() to shut down non-boot cpus > > and save registers' status in per-cpu ELF notes before starting crash > > dump kernel. See kernel_kexec(). > > Even if not all secondary cpus have shut down, we do kdump anyway. > > > > As we don't have to make non-boot(crashed) cpus offline (to preserve > > correct status of cpus at crash dump) before shutting down, this patch > > also adds a variant of smp_send_stop(). > > > > Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org> > > Reviewed-by: James Morse <james.morse at arm.com> > > Acked-by: Catalin Marinas <catalin.marinas at arm.com> > > --- > > arch/arm64/include/asm/hardirq.h | 2 +- > > arch/arm64/include/asm/kexec.h | 42 +++++++++++++++++++++++++- > > arch/arm64/include/asm/smp.h | 2 ++ > > arch/arm64/kernel/machine_kexec.c | 56 ++++++++++++++++++++++++++++++++-- > > arch/arm64/kernel/smp.c | 63 +++++++++++++++++++++++++++++++++++++++ > > 5 files changed, 160 insertions(+), 5 deletions(-) > > [...] > > > diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h > > index d050d720a1b4..cea009f2657d 100644 > > --- a/arch/arm64/include/asm/smp.h > > +++ b/arch/arm64/include/asm/smp.h > > @@ -148,6 +148,8 @@ static inline void cpu_panic_kernel(void) > > */ > > bool cpus_are_stuck_in_kernel(void); > > > > +extern void smp_send_crash_stop(void); > > + > > #endif /* ifndef __ASSEMBLY__ */ > > > > #endif /* ifndef __ASM_SMP_H */ > > diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c > > index bc96c8a7fc79..c60346d33bb1 100644 > > --- a/arch/arm64/kernel/machine_kexec.c > > +++ b/arch/arm64/kernel/machine_kexec.c > > @@ -9,6 +9,9 @@ > > * published by the Free Software Foundation. > > */ > > > > +#include <linux/interrupt.h> > > +#include <linux/irq.h> > > +#include <linux/kernel.h> > > #include <linux/kexec.h> > > #include <linux/smp.h> > > > > @@ -22,6 +25,7 @@ > > extern const unsigned char arm64_relocate_new_kernel[]; > > extern const unsigned long arm64_relocate_new_kernel_size; > > > > +static bool in_crash_kexec; > > Do you actually need this bool? Why not call kexec_crash_loaded() instead? The two have different meanings: "in_crash_kexec" indicates that kdump is taking place, while kexec_crash_loaded() tells us only whether crash dump kernel has been loaded or not. It is crucial to distinguish them especially for machine_kexec() which can be called on normal kexec even if kdump has been set up. Thanks, -Takahiro AKASHI > Will
