Commit 782276b4 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

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: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Acked-by: default avatarArd Biesheuvel <ardb@kernel.org>
Acked-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20210420093559.23168-1-catalin.marinas@arm.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent ef943405

arch/arm64/Kconfig

+1 −9
Original line number Diff line number Diff line
@@ -1040,15 +1040,7 @@ source "kernel/Kconfig.hz" 
config ARCH_SPARSEMEM_ENABLE

	def_bool y

	select SPARSEMEM_VMEMMAP_ENABLE



config ARCH_SPARSEMEM_DEFAULT

	def_bool ARCH_SPARSEMEM_ENABLE



config ARCH_SELECT_MEMORY_MODEL

	def_bool ARCH_SPARSEMEM_ENABLE



config ARCH_FLATMEM_ENABLE

	def_bool !NUMA

	select SPARSEMEM_VMEMMAP



config HW_PERF_EVENTS

	def_bool y

arch/arm64/include/asm/kernel-pgtable.h

+1 −1
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ 
 * has a direct correspondence, and needs to appear sufficiently aligned

 * in the virtual address space.

 */

#if defined(CONFIG_SPARSEMEM_VMEMMAP) && ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS

#if ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS

#define ARM64_MEMSTART_ALIGN	(1UL << SECTION_SIZE_BITS)

#else

#define ARM64_MEMSTART_ALIGN	(1UL << ARM64_MEMSTART_SHIFT)

arch/arm64/include/asm/memory.h

+2 −2
Original line number Diff line number Diff line
@@ -329,7 +329,7 @@ static inline void *phys_to_virt(phys_addr_t x) 
 */

#define ARCH_PFN_OFFSET		((unsigned long)PHYS_PFN_OFFSET)



#if !defined(CONFIG_SPARSEMEM_VMEMMAP) || defined(CONFIG_DEBUG_VIRTUAL)

#if defined(CONFIG_DEBUG_VIRTUAL)

#define page_to_virt(x)	({						\

	__typeof__(x) __page = x;					\

	void *__addr = __va(page_to_phys(__page));			\
@@ -349,7 +349,7 @@ static inline void *phys_to_virt(phys_addr_t x) 
	u64 __addr = VMEMMAP_START + (__idx * sizeof(struct page));	\

	(struct page *)__addr;						\

})

#endif /* !CONFIG_SPARSEMEM_VMEMMAP || CONFIG_DEBUG_VIRTUAL */

#endif /* CONFIG_DEBUG_VIRTUAL */



#define virt_addr_valid(addr)	({					\

	__typeof__(addr) __addr = __tag_reset(addr);			\

arch/arm64/include/asm/sparsemem.h

+0 −3
Original line number Diff line number Diff line
@@ -5,7 +5,6 @@ 
#ifndef __ASM_SPARSEMEM_H

#define __ASM_SPARSEMEM_H



#ifdef CONFIG_SPARSEMEM

#define MAX_PHYSMEM_BITS	CONFIG_ARM64_PA_BITS



/*
@@ -27,6 +26,4 @@ 
#define SECTION_SIZE_BITS 27

#endif /* CONFIG_ARM64_64K_PAGES */



#endif /* CONFIG_SPARSEMEM*/



#endif

arch/arm64/mm/init.c

+2 −6
Original line number Diff line number Diff line
@@ -220,6 +220,7 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) 
int pfn_valid(unsigned long pfn)

{

	phys_addr_t addr = PFN_PHYS(pfn);

	struct mem_section *ms;



	/*

	 * Ensure the upper PAGE_SHIFT bits are clear in the
@@ -230,10 +231,6 @@ int pfn_valid(unsigned long pfn) 
	if (PHYS_PFN(addr) != pfn)

		return 0;



#ifdef CONFIG_SPARSEMEM

{

	struct mem_section *ms;



	if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)

		return 0;
@@ -252,8 +249,7 @@ int pfn_valid(unsigned long pfn) 
	 */

	if (!early_section(ms))

		return pfn_section_valid(ms, pfn);

}

#endif



	return memblock_is_map_memory(addr);

}

EXPORT_SYMBOL(pfn_valid);