linux/arch/arm64/include/asm/sparsemem.h
Catalin Marinas 782276b4d0 arm64: Force SPARSEMEM_VMEMMAP as the only memory management model
Currently arm64 allows a choice of FLATMEM, SPARSEMEM and
SPARSEMEM_VMEMMAP. However, only the latter is tested regularly. FLATMEM
does not seem to boot in certain configurations (guest under KVM with
Qemu as a VMM). Since the reduction of the SECTION_SIZE_BITS to 27 (4K
pages) or 29 (64K page), there's little argument against the memory
wasted by the mem_map array with SPARSEMEM.

Make SPARSEMEM_VMEMMAP the only available option, non-selectable, and
remove the corresponding #ifdefs under arch/arm64/.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20210420093559.23168-1-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-23 14:18:21 +01:00

30 lines
682 B
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_SPARSEMEM_H
#define __ASM_SPARSEMEM_H
#define MAX_PHYSMEM_BITS CONFIG_ARM64_PA_BITS
/*
* Section size must be at least 512MB for 64K base
* page size config. Otherwise it will be less than
* (MAX_ORDER - 1) and the build process will fail.
*/
#ifdef CONFIG_ARM64_64K_PAGES
#define SECTION_SIZE_BITS 29
#else
/*
* Section size must be at least 128MB for 4K base
* page size config. Otherwise PMD based huge page
* entries could not be created for vmemmap mappings.
* 16K follows 4K for simplicity.
*/
#define SECTION_SIZE_BITS 27
#endif /* CONFIG_ARM64_64K_PAGES */
#endif