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 */