linux/arch/x86/include/asm/highmem.h
Minfei Huang 63e7b6d90c x86: mm: Re-use the early_ioremap fixed area
The temp fixed area is only used during boot for early_ioremap(), and
it is unused when ioremap() is functional. vmalloc/pkmap area become
available after early boot so the temp fixed area is available for
re-use.

The virtual address is more precious on i386, especially turning on
high memory. So we can re-use the virtual address space.

Remove the now unused defines FIXADDR_BOOT_START and FIXADDR_BOOT_SIZE.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Cc: pbonzini@redhat.com
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1414582717-32729-1-git-send-email-mnfhuang@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-03 13:40:44 +01:00

81 lines
2.6 KiB
C

/*
* highmem.h: virtual kernel memory mappings for high memory
*
* Used in CONFIG_HIGHMEM systems for memory pages which
* are not addressable by direct kernel virtual addresses.
*
* Copyright (C) 1999 Gerhard Wichert, Siemens AG
* Gerhard.Wichert@pdb.siemens.de
*
*
* Redesigned the x86 32-bit VM architecture to deal with
* up to 16 Terabyte physical memory. With current x86 CPUs
* we now support up to 64 Gigabytes physical RAM.
*
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
*/
#ifndef _ASM_X86_HIGHMEM_H
#define _ASM_X86_HIGHMEM_H
#ifdef __KERNEL__
#include <linux/interrupt.h>
#include <linux/threads.h>
#include <asm/kmap_types.h>
#include <asm/tlbflush.h>
#include <asm/paravirt.h>
#include <asm/fixmap.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))
extern void *kmap_high(struct page *page);
extern void kunmap_high(struct page *page);
void *kmap(struct page *page);
void kunmap(struct page *page);
void *kmap_atomic_prot(struct page *page, pgprot_t prot);
void *kmap_atomic(struct page *page);
void __kunmap_atomic(void *kvaddr);
void *kmap_atomic_pfn(unsigned long pfn);
void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
struct page *kmap_atomic_to_page(void *ptr);
#define flush_cache_kmaps() do { } while (0)
extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
unsigned long end_pfn);
#endif /* __KERNEL__ */
#endif /* _ASM_X86_HIGHMEM_H */