text: /* SPDX-License-Identifier: GPL-2.0
   *
   * This file contains the functions and defines necessary to modify and
   * use the SuperH page table tree.
   *
   * Copyright (C) 1999 Niibe Yutaka
   * Copyright (C) 2002 - 2007 Paul Mundt
   */
  #ifndef __ASM_SH_PGTABLE_H
  #define __ASM_SH_PGTABLE_H
  
  #ifdef CONFIG_X2TLB
  #include <asm/pgtable-3level.h>
  #else
  #include <asm/pgtable-2level.h>
  #endif
  #include <asm/page.h>
  #include <asm/mmu.h>
  
  #ifndef __ASSEMBLY__
  #include <asm/addrspace.h>
  #include <asm/fixmap.h>
  
  /*
   * ZERO_PAGE is a global shared page that is always zero: used
   * for zero-mapped memory areas etc..
   */
  extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
  
  #endif /* !__ASSEMBLY__ */
  
  /*
   * Effective and physical address definitions, to aid with sign
   * extension.
   */
  #define NEFF		32
  #define	NEFF_SIGN	(1LL << (NEFF - 1))
  #define	NEFF_MASK	(-1LL << NEFF)
  
  static inline unsigned long long neff_sign_extend(unsigned long val)
  {
  	unsigned long long extended = val;
  	return (extended & NEFF_SIGN) ? (extended | NEFF_MASK) : extended;
  }
  
  #ifdef CONFIG_29BIT
  #define NPHYS		29
  #else
  #define NPHYS		32
  #endif
  
  #define	NPHYS_SIGN	(1LL << (NPHYS - 1))
  #define	NPHYS_MASK	(-1LL << NPHYS)
  
  #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
  #define PGDIR_MASK	(~(PGDIR_SIZE-1))
  
  /* Entries per level */
  #define PTRS_PER_PTE	(PAGE_SIZE / (1 << PTE_MAGNITUDE))
  
  #define FIRST_USER_ADDRESS	0UL
  
  #define PHYS_ADDR_MASK29		0x1fffffff
  #define PHYS_ADDR_MASK32		0xffffffff
  
  static inline unsigned long phys_addr_mask(void)
  {
  	/* Is the MMU in 29bit mode? */
  	if (__in_29bit_mode())
  		return PHYS_ADDR_MASK29;
  
  	return PHYS_ADDR_MASK32;
  }
  
  #define PTE_PHYS_MASK		(phys_addr_mask() & PAGE_MASK)
  #define PTE_FLAGS_MASK		(~(PTE_PHYS_MASK) << PAGE_SHIFT)
  
  #ifdef CONFIG_SUPERH32
  #define VMALLOC_START	(P3SEG)
  #else
  #define VMALLOC_START	(0xf0000000)
  #endif
  #define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
  
  #if defined(CONFIG_SUPERH32)
  #include <asm/pgtable_32.h>
  #else
  #include <asm/pgtable_64.h>
  #endif
  
  /*
   * SH-X and lower (legacy) SuperH parts (SH-3, SH-4, some SH-4A) can't do page
   * protection for execute, and considers it the same as a read. Also, write
   * permission implies read permission. This is the closest we can get..
   *
   * SH-X2 (SH7785) and later parts take this to the opposite end of the extreme,
   * not only supporting separate execute, read, and write bits, but having
   * completely separate permission bits for user and kernel space.
   */
  	 /*xwr*/
  #define __P000	PAGE_NONE
  #define __P001	PAGE_READONLY
  #define __P010	PAGE_COPY
  #define __P011	PAGE_COPY
  #define __P100	PAGE_EXECREAD
  #define __P101	PAGE_EXECREAD
  #define __P110	PAGE_COPY
  #define __P111	PAGE_COPY
  
  #define __S000	PAGE_NONE
  #define __S001	PAGE_READONLY
  #define __S010	PAGE_WRITEONLY
  #define __S011	PAGE_SHARED
  #define __S100	PAGE_EXECREAD
  #define __S101	PAGE_EXECREAD
  #define __S110	PAGE_RWX
  #define __S111	PAGE_RWX
  
  typedef pte_t *pte_addr_t;
  
  #define kern_addr_valid(addr)	(1)
  
  #define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
  
  /*
   * Initialise the page table caches
   */
  extern void pgtable_cache_init(void);
  
  struct vm_area_struct;
  struct mm_struct;
  
  extern void __update_cache(struct vm_area_struct *vma,
  			   unsigned long address, pte_t pte);
  extern void __update_tlb(struct vm_area_struct *vma,
  			 unsigned long address, pte_t pte);
  
  static inline void
  update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
  {
  	pte_t pte = *ptep;
  	__update_cache(vma, address, pte);
  	__update_tlb(vma, address, pte);
  }
  
  extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  extern void paging_init(void);
  extern void page_table_range_init(unsigned long start, unsigned long end,
  				  pgd_t *pgd);
  
  /* arch/sh/mm/mmap.c */
  #define HAVE_ARCH_UNMAPPED_AREA
  #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
  
  #include <asm-generic/pgtable.h>
  
  #endif /* __ASM_SH_PGTABLE_H */
  