arch/x86/include/asm/highmem.h

Source file repositories/reference/linux-study-clean/arch/x86/include/asm/highmem.h

File Facts

System
Linux kernel
Corpus path
arch/x86/include/asm/highmem.h
Extension
.h
Size
2361 bytes
Lines
74
Domain
Architecture Layer
Bucket
arch/x86
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ASM_X86_HIGHMEM_H
#define _ASM_X86_HIGHMEM_H

#ifdef __KERNEL__

#include <linux/interrupt.h>
#include <linux/threads.h>
#include <asm/tlbflush.h>
#include <asm/fixmap.h>
#include <asm/pgtable_areas.h>

/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;

/*
 * Right now we initialize only a single pte table. It can be extended
 * easily, subsequent pte tables have to be allocated in one physical
 * chunk of RAM.
 */
/*
 * Ordering is:
 *
 * high memory on:			              high_memory off:
 *    FIXADDR_TOP                                        FIXADDR_TOP
 *        fixed addresses                                    fixed addresses
 *    FIXADDR_START                                      FIXADDR_START
 *        temp fixed addresses/persistent kmap area      VMALLOC_END
 *    PKMAP_BASE                                             temp fixed addresses/vmalloc area
 *    VMALLOC_END                                        VMALLOC_START
 *        vmalloc area                                   high_memory
 *    VMALLOC_START
 *    high_memory
 *
 * The temp fixed area is only used during boot for early_ioremap(), and
 * it is unused when the ioremap() is functional. vmalloc/pkmap area become
 * available after early boot so the temp fixed area is available for re-use.
 */
#define LAST_PKMAP_MASK (LAST_PKMAP-1)
#define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))

#define flush_cache_kmaps()	do { } while (0)

#define	arch_kmap_local_post_map(vaddr, pteval)		\
	arch_flush_lazy_mmu_mode()

#define	arch_kmap_local_post_unmap(vaddr)		\
	do {						\
		flush_tlb_one_kernel((vaddr));		\
		arch_flush_lazy_mmu_mode();		\
	} while (0)

#endif /* __KERNEL__ */

#endif /* _ASM_X86_HIGHMEM_H */

Annotation

Implementation Notes