Commit dca56dca authored by Mark Rutland's avatar Mark Rutland Committed by Catalin Marinas
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arm64: mm: add functions to walk page tables by PA 



To allow us to walk tables allocated into the fixmap, we need to acquire
the physical address of a page, rather than the virtual address in the
linear map.

This patch adds new p??_page_paddr and p??_offset_phys functions to
acquire the physical address of a next-level table, and changes
p??_offset* into macros which simply convert this to a linear map VA.
This renders p??_page_vaddr unused, and hence they are removed.

At the pgd level, a new pgd_offset_raw function is added to find the
relevant PGD entry given the base of a PGD and a virtual address.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Tested-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: default avatarJeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 053520f7

arch/arm64/include/asm/pgtable.h

+23 −16
Original line number Diff line number Diff line
@@ -422,15 +422,16 @@ static inline void pmd_clear(pmd_t *pmdp) 
	set_pmd(pmdp, __pmd(0));

}



static inline pte_t *pmd_page_vaddr(pmd_t pmd)

static inline phys_addr_t pmd_page_paddr(pmd_t pmd)

{

	return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);

	return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;

}



/* Find an entry in the third-level page table. */

#define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))



#define pte_offset_kernel(dir,addr)	(pmd_page_vaddr(*(dir)) + pte_index(addr))

#define pte_offset_phys(dir,addr)	(pmd_page_paddr(*(dir)) + pte_index(addr) * sizeof(pte_t))

#define pte_offset_kernel(dir,addr)	((pte_t *)__va(pte_offset_phys((dir), (addr))))



#define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))

#define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
@@ -465,21 +466,23 @@ static inline void pud_clear(pud_t *pudp) 
	set_pud(pudp, __pud(0));

}



static inline pmd_t *pud_page_vaddr(pud_t pud)

static inline phys_addr_t pud_page_paddr(pud_t pud)

{

	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);

	return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;

}



/* Find an entry in the second-level page table. */

#define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))



static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)

{

	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);

}

#define pmd_offset_phys(dir, addr)	(pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))

#define pmd_offset(dir, addr)		((pmd_t *)__va(pmd_offset_phys((dir), (addr))))



#define pud_page(pud)		pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))



#else



#define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })



#endif	/* CONFIG_PGTABLE_LEVELS > 2 */



#if CONFIG_PGTABLE_LEVELS > 3
@@ -501,21 +504,23 @@ static inline void pgd_clear(pgd_t *pgdp) 
	set_pgd(pgdp, __pgd(0));

}



static inline pud_t *pgd_page_vaddr(pgd_t pgd)

static inline phys_addr_t pgd_page_paddr(pgd_t pgd)

{

	return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);

	return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;

}



/* Find an entry in the frst-level page table. */

#define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))



static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)

{

	return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);

}

#define pud_offset_phys(dir, addr)	(pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))

#define pud_offset(dir, addr)		((pud_t *)__va(pud_offset_phys((dir), (addr))))



#define pgd_page(pgd)		pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))



#else



#define pgd_page_paddr(pgd)	({ BUILD_BUG(); 0;})



#endif  /* CONFIG_PGTABLE_LEVELS > 3 */



#define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
@@ -523,7 +528,9 @@ static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr) 
/* to find an entry in a page-table-directory */

#define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))



#define pgd_offset(mm, addr)	((mm)->pgd+pgd_index(addr))

#define pgd_offset_raw(pgd, addr)	((pgd) + pgd_index(addr))



#define pgd_offset(mm, addr)	(pgd_offset_raw((mm)->pgd, (addr)))



/* to find an entry in a kernel page-table-directory */

#define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)

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