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 prove 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  */
  37 typedef struct {
  38         unsigned long pte;
  39 } pte_t;
  40 typedef struct {
  41         unsigned long pmd[16];
  42 } pmd_t;
  43 typedef struct {
  44         unsigned long pgd;
  45 } pgd_t;
  46 typedef struct {
  47         unsigned long pgprot;
  48 } pgprot_t;
  49 typedef 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
  61 extern unsigned long memory_start;
  62 extern 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 */