Commit f8b46c4b authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Will Deacon
Browse files

arm64/mm: Add pud_sect_supported() 



Section mapping at PUD level is supported only on 4K pages and currently it
gets verified with explicit #ifdef or IS_ENABLED() constructs. This adds a
new helper pud_sect_supported() for this purpose, which particularly cleans
up the HugeTLB code path. It updates relevant switch statements with checks
for __PAGETABLE_PMD_FOLDED in order to avoid build failures caused with two
identical switch case values in those code blocks.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1632130171-472-1-git-send-email-anshuman.khandual@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent e63cf610

arch/arm64/include/asm/pgtable.h

+5 −0
Original line number Diff line number Diff line
@@ -1022,6 +1022,11 @@ static inline pgprot_t arch_filter_pgprot(pgprot_t prot) 
	return PAGE_READONLY_EXEC;

}



static inline bool pud_sect_supported(void)

{

	return PAGE_SIZE == SZ_4K;

}





#endif /* !__ASSEMBLY__ */

arch/arm64/include/asm/vmalloc.h

+2 −2
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#define _ASM_ARM64_VMALLOC_H



#include <asm/page.h>

#include <asm/pgtable.h>



#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
@@ -9,10 +10,9 @@ 
static inline bool arch_vmap_pud_supported(pgprot_t prot)

{

	/*

	 * Only 4k granule supports level 1 block mappings.

	 * SW table walks can't handle removal of intermediate entries.

	 */

	return IS_ENABLED(CONFIG_ARM64_4K_PAGES) &&

	return pud_sect_supported() &&

	       !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);

}

arch/arm64/mm/hugetlbpage.c

+15 −11
Original line number Diff line number Diff line
@@ -40,11 +40,10 @@ void __init arm64_hugetlb_cma_reserve(void) 
{

	int order;



#ifdef CONFIG_ARM64_4K_PAGES

	if (pud_sect_supported())

		order = PUD_SHIFT - PAGE_SHIFT;

#else

	else

		order = CONT_PMD_SHIFT + PMD_SHIFT - PAGE_SHIFT;

#endif

	/*

	 * HugeTLB CMA reservation is required for gigantic

	 * huge pages which could not be allocated via the
@@ -62,8 +61,9 @@ bool arch_hugetlb_migration_supported(struct hstate *h) 
	size_t pagesize = huge_page_size(h);



	switch (pagesize) {

#ifdef CONFIG_ARM64_4K_PAGES

#ifndef __PAGETABLE_PMD_FOLDED

	case PUD_SIZE:

		return pud_sect_supported();

#endif

	case PMD_SIZE:

	case CONT_PMD_SIZE:
@@ -126,8 +126,11 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize) 
	*pgsize = size;



	switch (size) {

#ifdef CONFIG_ARM64_4K_PAGES

#ifndef __PAGETABLE_PMD_FOLDED

	case PUD_SIZE:

		if (pud_sect_supported())

			contig_ptes = 1;

		break;

#endif

	case PMD_SIZE:

		contig_ptes = 1;
@@ -489,9 +492,9 @@ void huge_ptep_clear_flush(struct vm_area_struct *vma, 


static int __init hugetlbpage_init(void)

{

#ifdef CONFIG_ARM64_4K_PAGES

	if (pud_sect_supported())

		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);

#endif



	hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT);

	hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);

	hugetlb_add_hstate(CONT_PTE_SHIFT - PAGE_SHIFT);
@@ -503,8 +506,9 @@ arch_initcall(hugetlbpage_init); 
bool __init arch_hugetlb_valid_size(unsigned long size)

{

	switch (size) {

#ifdef CONFIG_ARM64_4K_PAGES

#ifndef __PAGETABLE_PMD_FOLDED

	case PUD_SIZE:

		return pud_sect_supported();

#endif

	case CONT_PMD_SIZE:

	case PMD_SIZE: