original_kernel/include/asm-generic/memory_model.h

70 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_MEMORY_MODEL_H
#define __ASM_MEMORY_MODEL_H
#include <linux/pfn.h>
#ifndef __ASSEMBLY__
/*
* supports 3 memory models.
*/
#if defined(CONFIG_FLATMEM)
#ifndef ARCH_PFN_OFFSET
#define ARCH_PFN_OFFSET (0UL)
#endif
#define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
#define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
ARCH_PFN_OFFSET)
#ifndef pfn_valid
static inline int pfn_valid(unsigned long pfn)
{
/* avoid <linux/mm.h> include hell */
extern unsigned long max_mapnr;
unsigned long pfn_offset = ARCH_PFN_OFFSET;
return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr;
}
#define pfn_valid pfn_valid
#endif
#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
/* memmap is virtually contiguous. */
#define __pfn_to_page(pfn) (vmemmap + (pfn))
#define __page_to_pfn(page) (unsigned long)((page) - vmemmap)
#elif defined(CONFIG_SPARSEMEM)
/*
* Note: section's mem_map is encoded to reflect its start_pfn.
* section[i].section_mem_map == mem_map's address - start_pfn;
*/
#define __page_to_pfn(pg) \
({ const struct page *__pg = (pg); \
int __sec = page_to_section(__pg); \
(unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
})
#define __pfn_to_page(pfn) \
({ unsigned long __pfn = (pfn); \
struct mem_section *__sec = __pfn_to_section(__pfn); \
__section_mem_map_addr(__sec) + __pfn; \
})
#endif /* CONFIG_FLATMEM/SPARSEMEM */
/*
* Convert a physical address to a Page Frame Number and back
*/
#define __phys_to_pfn(paddr) PHYS_PFN(paddr)
#define __pfn_to_phys(pfn) PFN_PHYS(pfn)
#define page_to_pfn __page_to_pfn
#define pfn_to_page __pfn_to_page
#endif /* __ASSEMBLY__ */
#endif