| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _X86_CRASH_RESERVE_H |
| #define _X86_CRASH_RESERVE_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_RESERVE_H */ |
