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author | Baoquan He <bhe@redhat.com> | 2023-09-14 06:31:39 +0300 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-04 20:41:58 +0300 |
commit | 9c08a2a139fe83f217625ee0352ce531b9a666ea (patch) | |
tree | 0dc5154c7c94826008f444c54ec5e3677e07d772 /arch/x86/include/asm/crash_core.h | |
parent | b631b95dded5e7f007a3a79cbaf82ef50c1e2cf7 (diff) | |
download | linux-9c08a2a139fe83f217625ee0352ce531b9a666ea.tar.xz |
x86: kdump: use generic interface to simplify crashkernel reservation code
With the help of newly changed function parse_crashkernel() and generic
reserve_crashkernel_generic(), crashkernel reservation can be simplified
by steps:
1) Add a new header file <asm/crash_core.h>, and define CRASH_ALIGN,
CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and
DEFAULT_CRASH_KERNEL_LOW_SIZE in <asm/crash_core.h>;
2) Add arch_reserve_crashkernel() to call parse_crashkernel() and
reserve_crashkernel_generic(), and do the ARCH specific work if
needed.
3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in
arch/x86/Kconfig.
When adding DEFAULT_CRASH_KERNEL_LOW_SIZE, add crash_low_size_default() to
calculate crashkernel low memory because x86_64 has special requirement.
The old reserve_crashkernel_low() and reserve_crashkernel() can be
removed.
[bhe@redhat.com: move crash_low_size_default() code into <asm/crash_core.h>]
Link: https://lkml.kernel.org/r/ZQpeAjOmuMJBFw1/@MiWiFi-R3L-srv
Link: https://lkml.kernel.org/r/20230914033142.676708-7-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/x86/include/asm/crash_core.h')
-rw-r--r-- | arch/x86/include/asm/crash_core.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/x86/include/asm/crash_core.h b/arch/x86/include/asm/crash_core.h new file mode 100644 index 000000000000..76af98f4e801 --- /dev/null +++ b/arch/x86/include/asm/crash_core.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _X86_CRASH_CORE_H +#define _X86_CRASH_CORE_H + +/* 16M alignment for crash kernel regions */ +#define CRASH_ALIGN SZ_16M + +/* + * Keep the crash kernel below this limit. + * + * Earlier 32-bits kernels would limit the kernel to the low 512 MB range + * due to mapping restrictions. + * + * 64-bit kdump kernels need to be restricted to be under 64 TB, which is + * the upper limit of system RAM in 4-level paging mode. Since the kdump + * jump could be from 5-level paging to 4-level paging, the jump will fail if + * the kernel is put above 64 TB, and during the 1st kernel bootup there's + * no good way to detect the paging mode of the target kernel which will be + * loaded for dumping. + */ +extern unsigned long swiotlb_size_or_default(void); + +#ifdef CONFIG_X86_32 +# define CRASH_ADDR_LOW_MAX SZ_512M +# define CRASH_ADDR_HIGH_MAX SZ_512M +#else +# define CRASH_ADDR_LOW_MAX SZ_4G +# define CRASH_ADDR_HIGH_MAX SZ_64T +#endif + +# define DEFAULT_CRASH_KERNEL_LOW_SIZE crash_low_size_default() + +static inline unsigned long crash_low_size_default(void) +{ +#ifdef CONFIG_X86_64 + return max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); +#else + return 0; +#endif +} + +#endif /* _X86_CRASH_CORE_H */ |