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/* 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 */