cregit-Linux how code gets into the kernel

Release 4.7 include/asm-generic/page.h

#ifndef __ASM_GENERIC_PAGE_H

#define __ASM_GENERIC_PAGE_H
/*
 * Generic page.h implementation, for NOMMU architectures.
 * This provides the dummy definitions for the memory management.
 */

#ifdef CONFIG_MMU
#error need to prove a real asm/page.h
#endif


/* PAGE_SHIFT determines the page size */


#define PAGE_SHIFT	12
#ifdef __ASSEMBLY__

#define PAGE_SIZE	(1 << PAGE_SHIFT)
#else

#define PAGE_SIZE	(1UL << PAGE_SHIFT)
#endif

#define PAGE_MASK	(~(PAGE_SIZE-1))

#include <asm/setup.h>

#ifndef __ASSEMBLY__


#define clear_page(page)	memset((page), 0, PAGE_SIZE)

#define copy_page(to,from)	memcpy((to), (from), PAGE_SIZE)


#define clear_user_page(page, vaddr, pg)	clear_page(page)

#define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)

/*
 * These are used to make use of C type-checking..
 */
typedef struct {
	
unsigned long pte;
} 
pte_t;
typedef struct {
	
unsigned long pmd[16];
} 
pmd_t;
typedef struct {
	
unsigned long pgd;
} 
pgd_t;
typedef struct {
	
unsigned long pgprot;
} 
pgprot_t;

typedef struct page *pgtable_t;


#define pte_val(x)	((x).pte)

#define pmd_val(x)	((&x)->pmd[0])

#define pgd_val(x)	((x).pgd)

#define pgprot_val(x)	((x).pgprot)


#define __pte(x)	((pte_t) { (x) } )

#define __pmd(x)	((pmd_t) { (x) } )

#define __pgd(x)	((pgd_t) { (x) } )

#define __pgprot(x)	((pgprot_t) { (x) } )

extern unsigned long memory_start;
extern unsigned long memory_end;

#endif /* !__ASSEMBLY__ */

#ifdef CONFIG_KERNEL_RAM_BASE_ADDRESS

#define PAGE_OFFSET		(CONFIG_KERNEL_RAM_BASE_ADDRESS)
#else

#define PAGE_OFFSET		(0)
#endif

#ifndef ARCH_PFN_OFFSET

#define ARCH_PFN_OFFSET		(PAGE_OFFSET >> PAGE_SHIFT)
#endif

#ifndef __ASSEMBLY__


#define __va(x) ((void *)((unsigned long) (x)))

#define __pa(x) ((unsigned long) (x))


#define virt_to_pfn(kaddr)	(__pa(kaddr) >> PAGE_SHIFT)

#define pfn_to_virt(pfn)	__va((pfn) << PAGE_SHIFT)


#define virt_to_page(addr)	pfn_to_page(virt_to_pfn(addr))

#define page_to_virt(page)	pfn_to_virt(page_to_pfn(page))

#ifndef page_to_phys

#define page_to_phys(page)      ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
#endif


#define pfn_valid(pfn)		((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)


#define	virt_addr_valid(kaddr)	(((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
                                ((void *)(kaddr) < (void *)memory_end))

#endif /* __ASSEMBLY__ */

#include <asm-generic/memory_model.h>
#include <asm-generic/getorder.h>

#endif /* __ASM_GENERIC_PAGE_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
arnd bergmannarnd bergmann29795.50%133.33%
mark saltermark salter123.86%133.33%
sonic zhangsonic zhang20.64%133.33%
Total311100.00%3100.00%
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