arch/sh/include/asm/pgtable-3level.h

Source file repositories/reference/linux-study-clean/arch/sh/include/asm/pgtable-3level.h

File Facts

System
Linux kernel
Corpus path
arch/sh/include/asm/pgtable-3level.h
Extension
.h
Size
1536 bytes
Lines
60
Domain
Architecture Layer
Bucket
arch/sh
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef __ASM_SH_PGTABLE_3LEVEL_H
#define __ASM_SH_PGTABLE_3LEVEL_H

#include <asm-generic/pgtable-nopud.h>

/*
 * Some cores need a 3-level page table layout, for example when using
 * 64-bit PTEs and 4K pages.
 */
#define PAGETABLE_LEVELS	3

#define PTE_MAGNITUDE		3	/* 64-bit PTEs on SH-X2 TLB */

/* PGD bits */
#define PGDIR_SHIFT		30

#define PTRS_PER_PGD		4
#define USER_PTRS_PER_PGD	2

/* PMD bits */
#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT - PTE_MAGNITUDE))
#define PMD_SIZE	(1UL << PMD_SHIFT)
#define PMD_MASK	(~(PMD_SIZE-1))

#define PTRS_PER_PMD	((1 << PGDIR_SHIFT) / PMD_SIZE)

#define pmd_ERROR(e) \
	printk("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))

typedef union {
	struct {
		unsigned long pmd_low;
		unsigned long pmd_high;
	};
	unsigned long long pmd;
} pmd_t;
#define pmd_val(x)	((x).pmd)
#define __pmd(x)	((pmd_t) { .pmd = (x) } )

static inline pmd_t *pud_pgtable(pud_t pud)
{
	return (pmd_t *)(unsigned long)pud_val(pud);
}

/* only used by the stubbed out hugetlb gup code, should never be called */
#define pud_page(pud)		NULL
#define pud_none(x)	(!pud_val(x))
#define pud_present(x)	(pud_val(x))
#define pud_clear(xp)	do { set_pud(xp, __pud(0)); } while (0)
#define	pud_bad(x)	(pud_val(x) & ~PAGE_MASK)

/*
 * (puds are folded into pgds so this doesn't get actually called,
 * but the define is needed for a generic inline function.)
 */
#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)

#endif /* __ASM_SH_PGTABLE_3LEVEL_H */

Annotation

Implementation Notes