On 11/12/20 at 10:25am, Mike Rapoport wrote:
> On Wed, Nov 11, 2020 at 09:54:48PM +0800, Baoquan He wrote:
> > On 11/11/20 at 09:27pm, chenzhou wrote:
> > > Hi Baoquan,
> > ...
> > > >> #ifdef CONFIG_CRASH_DUMP
> > > >> static int __init early_init_dt_scan_elfcorehdr(unsigned long node,
> > > >> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> > > >> index 1c0f3e02f731..c55cee290bbb 100644
> > > >> --- a/arch/arm64/mm/mmu.c
> > > >> +++ b/arch/arm64/mm/mmu.c
> > > >> @@ -488,6 +488,10 @@ static void __init map_mem(pgd_t *pgdp)
> > > >> */
> > > >> memblock_mark_nomap(kernel_start, kernel_end - kernel_start);
> > > >> #ifdef CONFIG_KEXEC_CORE
> > > >> + if (crashk_low_res.end)
> > > >> + memblock_mark_nomap(crashk_low_res.start,
> > > >> + resource_size(&crashk_low_res));
> > > >> +
> > > >> if (crashk_res.end)
> > > >> memblock_mark_nomap(crashk_res.start,
> > > >> resource_size(&crashk_res));
> > > >> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> > > >> index d39892bdb9ae..cdef7d8c91a6 100644
> > > >> --- a/kernel/crash_core.c
> > > >> +++ b/kernel/crash_core.c
> > > >> @@ -321,7 +321,7 @@ int __init parse_crashkernel_low(char *cmdline,
> > > >>
> > > >> int __init reserve_crashkernel_low(void)
> > > >> {
> > > >> -#ifdef CONFIG_X86_64
> > > >> +#if defined(CONFIG_X86_64) || defined(CONFIG_ARM64)
> > > > Not very sure if a CONFIG_64BIT checking is better.
> > > If doing like this, there may be some compiling errors for other 64-bit
> > > kernel, such as mips.
> > > >
> > > >> unsigned long long base, low_base = 0, low_size = 0;
> > > >> unsigned long low_mem_limit;
> > > >> int ret;
> > > >> @@ -362,12 +362,14 @@ int __init reserve_crashkernel_low(void)
> > > >>
> > > >> crashk_low_res.start = low_base;
> > > >> crashk_low_res.end = low_base + low_size - 1;
> > > >> +#ifdef CONFIG_X86_64
> > > >> insert_resource(&iomem_resource, &crashk_low_res);
> > > >> +#endif
> > > >> #endif
> > > >> return 0;
> > > >> }
> > > >>
> > > >> -#ifdef CONFIG_X86
> > > >> +#if defined(CONFIG_X86) || defined(CONFIG_ARM64)
> > > > Should we make this weak default so that we can remove the ARCH config?
> > > The same as above, some arch may not support kdump, in that case,
> > > compiling errors occur.
> >
> > OK, not sure if other people have better idea, oterwise, we can leave with
> > it.
> > Thanks for telling.
>
> I think it would be better to have CONFIG_ARCH_WANT_RESERVE_CRASH_KERNEL
> in arch/Kconfig and select this by X86 and ARM64.
>
> Since reserve_crashkernel() implementations are quite similart on other
> architectures as well, we can have more users of this later.
Yes, this sounds like a nice way.
