linux/arch/riscv/include/asm/pgtable-64.h
Palmer Dabbelt 07037db5d4 RISC-V: Paging and MMU
This patch contains code to manage the RISC-V MMU, including definitions
of the page tables and the page walking code.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:47 -07:00

85 lines
2.1 KiB
C

/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _ASM_RISCV_PGTABLE_64_H
#define _ASM_RISCV_PGTABLE_64_H
#include <linux/const.h>
#define PGDIR_SHIFT 30
/* Size of region mapped by a page global directory */
#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE - 1))
#define PMD_SHIFT 21
/* Size of region mapped by a page middle directory */
#define PMD_SIZE (_AC(1, UL) << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE - 1))
/* Page Middle Directory entry */
typedef struct {
unsigned long pmd;
} pmd_t;
#define pmd_val(x) ((x).pmd)
#define __pmd(x) ((pmd_t) { (x) })
#define PTRS_PER_PMD (PAGE_SIZE / sizeof(pmd_t))
static inline int pud_present(pud_t pud)
{
return (pud_val(pud) & _PAGE_PRESENT);
}
static inline int pud_none(pud_t pud)
{
return (pud_val(pud) == 0);
}
static inline int pud_bad(pud_t pud)
{
return !pud_present(pud);
}
static inline void set_pud(pud_t *pudp, pud_t pud)
{
*pudp = pud;
}
static inline void pud_clear(pud_t *pudp)
{
set_pud(pudp, __pud(0));
}
static inline unsigned long pud_page_vaddr(pud_t pud)
{
return (unsigned long)pfn_to_virt(pud_val(pud) >> _PAGE_PFN_SHIFT);
}
#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);
}
static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)
{
return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
}
#define pmd_ERROR(e) \
pr_err("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
#endif /* _ASM_RISCV_PGTABLE_64_H */