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Commit 2b77933c authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Move to 64-bit PGDs and PMDs. 



To make the page tables compact, we were using 32-bit PGDs and PMDs.
We only had to support <= 43 bits of physical addresses so this was
quite feasible.

In order to support larger physical addresses we have to move to
64-bit PGDs and PMDs.

Most of the changes are straight-forward:

1) {pgd,pmd}_t --> unsigned long

2) Anything that tries to use plain "unsigned int" types with pgd/pmd
   values needs to be adjusted.  In particular things like "0U" become
   "0UL".

3) {PGDIR,PMD}_BITS decrease by one.

4) In the assembler page table walkers, use "ldxa" instead of "lduwa"
   and adjust the low bit masks to clear out the low 3 bits instead of
   just the low 2 bits during pgd/pmd address formation.

Also, use PTRS_PER_PGD and PTRS_PER_PMD in the sizing of the
swapper_{pg_dir,low_pmd_dir} arrays.

This patch does not try to take advantage of having 64-bits in the
PMDs to simplify the hugepage code, that will come in a subsequent
change.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 37b3a8ff

arch/sparc/include/asm/page_64.h

+14 −11
Original line number Diff line number Diff line
@@ -56,8 +56,8 @@ extern void copy_user_page(void *to, void *from, unsigned long vaddr, struct pag 
/* These are used to make use of C type-checking.. */

typedef struct { unsigned long pte; } pte_t;

typedef struct { unsigned long iopte; } iopte_t;

typedef struct { unsigned int pmd; } pmd_t;

typedef struct { unsigned int pgd; } pgd_t;

typedef struct { unsigned long pmd; } pmd_t;

typedef struct { unsigned long pgd; } pgd_t;

typedef struct { unsigned long pgprot; } pgprot_t;



#define pte_val(x)	((x).pte)
@@ -76,8 +76,8 @@ typedef struct { unsigned long pgprot; } pgprot_t; 
/* .. while these make it easier on the compiler */

typedef unsigned long pte_t;

typedef unsigned long iopte_t;

typedef unsigned int pmd_t;

typedef unsigned int pgd_t;

typedef unsigned long pmd_t;

typedef unsigned long pgd_t;

typedef unsigned long pgprot_t;



#define pte_val(x)	(x)
@@ -97,15 +97,18 @@ typedef unsigned long pgprot_t; 
typedef pte_t *pgtable_t;



/* These two values define the virtual address space range in which we

 * must forbid 64-bit user processes from making mappings.  It

 * represents the virtual address space hole present in most early

 * sparc64 chips including UltraSPARC-I.  The next two defines specify

 * the actual exclusion region we enforce, wherein we use a 4GB red

 * zone on each side of the VA hole.

 * must forbid 64-bit user processes from making mappings.  It used to

 * represent precisely the virtual address space hole present in most

 * early sparc64 chips including UltraSPARC-I.  But now it also is

 * further constrained by the limits of our page tables, which is

 * 43-bits of virtual address.

 */

#define SPARC64_VA_HOLE_TOP	_AC(0xfffff80000000000,UL)

#define SPARC64_VA_HOLE_BOTTOM	_AC(0x0000080000000000,UL)

#define SPARC64_VA_HOLE_TOP	_AC(0xfffffc0000000000,UL)

#define SPARC64_VA_HOLE_BOTTOM	_AC(0x0000040000000000,UL)



/* The next two defines specify the actual exclusion region we

 * enforce, wherein we use a 4GB red zone on each side of the VA hole.

 */

#define VA_EXCLUDE_START (SPARC64_VA_HOLE_BOTTOM - (1UL << 32UL))

#define VA_EXCLUDE_END   (SPARC64_VA_HOLE_TOP + (1UL << 32UL))

arch/sparc/include/asm/pgtable_64.h

+11 −11
Original line number Diff line number Diff line
@@ -51,15 +51,15 @@ 
#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT-3))

#define PMD_SIZE	(_AC(1,UL) << PMD_SHIFT)

#define PMD_MASK	(~(PMD_SIZE-1))

#define PMD_BITS	(PAGE_SHIFT - 2)

#define PMD_BITS	(PAGE_SHIFT - 3)



/* PGDIR_SHIFT determines what a third-level page table entry can map */

#define PGDIR_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT-3) + PMD_BITS)

#define PGDIR_SIZE	(_AC(1,UL) << PGDIR_SHIFT)

#define PGDIR_MASK	(~(PGDIR_SIZE-1))

#define PGDIR_BITS	(PAGE_SHIFT - 2)

#define PGDIR_BITS	(PAGE_SHIFT - 3)



#if (PGDIR_SHIFT + PGDIR_BITS) != 45

#if (PGDIR_SHIFT + PGDIR_BITS) != 43

#error Page table parameters do not cover virtual address space properly.

#endif
@@ -714,7 +714,7 @@ extern pgprot_t pmd_pgprot(pmd_t entry); 


static inline int pmd_present(pmd_t pmd)

{

	return pmd_val(pmd) != 0U;

	return pmd_val(pmd) != 0UL;

}



#define pmd_none(pmd)			(!pmd_val(pmd))
@@ -741,7 +741,7 @@ static inline void pmd_set(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep) 
	(pud_val(*(pudp)) = (__pa((unsigned long) (pmdp)) >> PGD_PADDR_SHIFT))

static inline unsigned long __pmd_page(pmd_t pmd)

{

	unsigned long paddr = (unsigned long) pmd_val(pmd);

	unsigned long paddr = pmd_val(pmd);

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	if (pmd_val(pmd) & PMD_ISHUGE)

		paddr &= PMD_HUGE_PADDR;
@@ -751,14 +751,14 @@ static inline unsigned long __pmd_page(pmd_t pmd) 
}

#define pmd_page(pmd) 			virt_to_page((void *)__pmd_page(pmd))

#define pud_page_vaddr(pud)		\

	((unsigned long) __va((((unsigned long)pud_val(pud))<<PGD_PADDR_SHIFT)))

	((unsigned long) __va((pud_val(pud)<<PGD_PADDR_SHIFT)))

#define pud_page(pud) 			virt_to_page((void *)pud_page_vaddr(pud))

#define pmd_bad(pmd)			(0)

#define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0U)

#define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0UL)

#define pud_none(pud)			(!pud_val(pud))

#define pud_bad(pud)			(0)

#define pud_present(pud)		(pud_val(pud) != 0U)

#define pud_clear(pudp)			(pud_val(*(pudp)) = 0U)

#define pud_clear(pudp)			(pud_val(*(pudp)) = 0UL)



/* Same in both SUN4V and SUN4U.  */

#define pte_none(pte) 			(!pte_val(pte))
@@ -793,7 +793,7 @@ static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm, 
				       pmd_t *pmdp)

{

	pmd_t pmd = *pmdp;

	set_pmd_at(mm, addr, pmdp, __pmd(0U));

	set_pmd_at(mm, addr, pmdp, __pmd(0UL));

	return pmd;

}
@@ -841,8 +841,8 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, 
})

#endif



extern pgd_t swapper_pg_dir[2048];

extern pmd_t swapper_low_pmd_dir[2048];

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

extern pmd_t swapper_low_pmd_dir[PTRS_PER_PMD];



extern void paging_init(void);

extern unsigned long find_ecache_flush_span(unsigned long size);

arch/sparc/include/asm/tsb.h

+8 −8
Original line number Diff line number Diff line
@@ -142,14 +142,14 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end; 
	or		REG1, %lo(swapper_pg_dir), REG1; \

	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \

	srlx		REG2, 64 - PAGE_SHIFT, REG2; \

	andn		REG2, 0x3, REG2; \

	lduw		[REG1 + REG2], REG1; \

	andn		REG2, 0x7, REG2; \

	ldx		[REG1 + REG2], REG1; \

	brz,pn		REG1, FAIL_LABEL; \

	 sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \

	srlx		REG2, 64 - PAGE_SHIFT, REG2; \

	sllx		REG1, PGD_PADDR_SHIFT, REG1; \

	andn		REG2, 0x3, REG2; \

	lduwa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \

	andn		REG2, 0x7, REG2; \

	ldxa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \

	brz,pn		REG1, FAIL_LABEL; \

	 sllx		VADDR, 64 - PMD_SHIFT, REG2; \

	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
@@ -260,14 +260,14 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end; 
#define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL)	\

	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \

	srlx		REG2, 64 - PAGE_SHIFT, REG2; \

	andn		REG2, 0x3, REG2; \

	lduwa		[PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \

	andn		REG2, 0x7, REG2; \

	ldxa		[PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \

	brz,pn		REG1, FAIL_LABEL; \

	 sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \

	srlx		REG2, 64 - PAGE_SHIFT, REG2; \

	sllx		REG1, PGD_PADDR_SHIFT, REG1; \

	andn		REG2, 0x3, REG2; \

	lduwa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \

	andn		REG2, 0x7, REG2; \

	ldxa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \

	USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, 800f) \

	sllx		VADDR, 64 - PMD_SHIFT, REG2; \

	srlx		REG2, 64 - PAGE_SHIFT, REG2; \

arch/sparc/mm/init_64.c

+1 −1
Original line number Diff line number Diff line
@@ -1842,7 +1842,7 @@ static void __init sun4v_linear_pte_xor_finalize(void) 
/* paging_init() sets up the page tables */



static unsigned long last_valid_pfn;

pgd_t swapper_pg_dir[2048];

pgd_t swapper_pg_dir[PTRS_PER_PGD];



static void sun4u_pgprot_init(void);

static void sun4v_pgprot_init(void);