LXR linux/include/asm-generic/page.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __ASM_GENERIC_PAGE_H
   3#define __ASM_GENERIC_PAGE_H
   4/*
   5 * Generic page.h implementation, for NOMMU architectures.
   6 * This provides the dummy definitions for the memory management.
   7 */
   8
   9#ifdef CONFIG_MMU
  10#error need to provide a real asm/page.h
  11#endif
  12
  13
  14/* PAGE_SHIFT determines the page size */
  15
  16#define PAGE_SHIFT      12
  17#ifdef __ASSEMBLY__
  18#define PAGE_SIZE       (1 << PAGE_SHIFT)
  19#else
  20#define PAGE_SIZE       (1UL << PAGE_SHIFT)
  21#endif
  22#define PAGE_MASK       (~(PAGE_SIZE-1))
  23
  24#include <asm/setup.h>
  25
  26#ifndef __ASSEMBLY__
  27
  28#define clear_page(page)        memset((page), 0, PAGE_SIZE)
  29#define copy_page(to,from)      memcpy((to), (from), PAGE_SIZE)
  30
  31#define clear_user_page(page, vaddr, pg)        clear_page(page)
  32#define copy_user_page(to, from, vaddr, pg)     copy_page(to, from)
  33
  34/*
  35 * These are used to make use of C type-checking..
  36 */
  37typedef struct {
  38        unsigned long pte;
  39} pte_t;
  40typedef struct {
  41        unsigned long pmd[16];
  42} pmd_t;
  43typedef struct {
  44        unsigned long pgd;
  45} pgd_t;
  46typedef struct {
  47        unsigned long pgprot;
  48} pgprot_t;
  49typedef struct page *pgtable_t;
  50
  51#define pte_val(x)      ((x).pte)
  52#define pmd_val(x)      ((&x)->pmd[0])
  53#define pgd_val(x)      ((x).pgd)
  54#define pgprot_val(x)   ((x).pgprot)
  55
  56#define __pte(x)        ((pte_t) { (x) } )
  57#define __pmd(x)        ((pmd_t) { (x) } )
  58#define __pgd(x)        ((pgd_t) { (x) } )
  59#define __pgprot(x)     ((pgprot_t) { (x) } )
  60
  61extern unsigned long memory_start;
  62extern unsigned long memory_end;
  63
  64#endif /* !__ASSEMBLY__ */
  65
  66#ifdef CONFIG_KERNEL_RAM_BASE_ADDRESS
  67#define PAGE_OFFSET             (CONFIG_KERNEL_RAM_BASE_ADDRESS)
  68#else
  69#define PAGE_OFFSET             (0)
  70#endif
  71
  72#ifndef ARCH_PFN_OFFSET
  73#define ARCH_PFN_OFFSET         (PAGE_OFFSET >> PAGE_SHIFT)
  74#endif
  75
  76#ifndef __ASSEMBLY__
  77
  78#define __va(x) ((void *)((unsigned long) (x)))
  79#define __pa(x) ((unsigned long) (x))
  80
  81#define virt_to_pfn(kaddr)      (__pa(kaddr) >> PAGE_SHIFT)
  82#define pfn_to_virt(pfn)        __va((pfn) << PAGE_SHIFT)
  83
  84#define virt_to_page(addr)      pfn_to_page(virt_to_pfn(addr))
  85#define page_to_virt(page)      pfn_to_virt(page_to_pfn(page))
  86
  87#ifndef page_to_phys
  88#define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
  89#endif
  90
  91#define pfn_valid(pfn)          ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)
  92
  93#define virt_addr_valid(kaddr)  (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
  94                                ((void *)(kaddr) < (void *)memory_end))
  95
  96#endif /* __ASSEMBLY__ */
  97
  98#include <asm-generic/memory_model.h>
  99#include <asm-generic/getorder.h>
 100
 101#endif /* __ASM_GENERIC_PAGE_H */
 102