102 lines
2.9 KiB
C
102 lines
2.9 KiB
C
/*
|
|
* fixmap.h: compile-time virtual memory allocation
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*
|
|
* Copyright (C) 1998 Ingo Molnar
|
|
*
|
|
* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
|
|
*/
|
|
|
|
#ifndef _ASM_FIXMAP_H
|
|
#define _ASM_FIXMAP_H
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/threads.h>
|
|
#include <asm/page.h>
|
|
#ifdef CONFIG_HIGHMEM
|
|
#include <asm/kmap_types.h>
|
|
#endif
|
|
|
|
/*
|
|
* Here we define all the compile-time 'special' virtual
|
|
* addresses. The point is to have a constant address at
|
|
* compile time, but to set the physical address only
|
|
* in the boot process. We allocate these special addresses
|
|
* from the end of P3 backwards.
|
|
* Also this lets us do fail-safe vmalloc(), we
|
|
* can guarantee that these special addresses and
|
|
* vmalloc()-ed addresses never overlap.
|
|
*
|
|
* these 'compile-time allocated' memory buffers are
|
|
* fixed-size 4k pages. (or larger if used with an increment
|
|
* highger than 1) use fixmap_set(idx,phys) to associate
|
|
* physical memory with fixmap indices.
|
|
*
|
|
* TLB entries of such buffers will not be flushed across
|
|
* task switches.
|
|
*/
|
|
|
|
/*
|
|
* on UP currently we will have no trace of the fixmap mechanizm,
|
|
* no page table allocations, etc. This might change in the
|
|
* future, say framebuffers for the console driver(s) could be
|
|
* fix-mapped?
|
|
*/
|
|
enum fixed_addresses {
|
|
/*
|
|
* The FIX_CMAP entries are used by kmap_coherent() to get virtual
|
|
* addresses which are of a known color, and so their values are
|
|
* important. __fix_to_virt(FIX_CMAP_END - n) must give an address
|
|
* which is the same color as a page (n<<PAGE_SHIFT).
|
|
*/
|
|
#define FIX_N_COLOURS 8
|
|
FIX_CMAP_BEGIN,
|
|
FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS) - 1,
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
|
|
FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
|
|
#endif
|
|
|
|
#ifdef CONFIG_IOREMAP_FIXED
|
|
/*
|
|
* FIX_IOREMAP entries are useful for mapping physical address
|
|
* space before ioremap() is useable, e.g. really early in boot
|
|
* before kmalloc() is working.
|
|
*/
|
|
#define FIX_N_IOREMAPS 32
|
|
FIX_IOREMAP_BEGIN,
|
|
FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1,
|
|
#endif
|
|
|
|
__end_of_fixed_addresses
|
|
};
|
|
|
|
extern void __set_fixmap(enum fixed_addresses idx,
|
|
unsigned long phys, pgprot_t flags);
|
|
extern void __clear_fixmap(enum fixed_addresses idx, pgprot_t flags);
|
|
|
|
/*
|
|
* used by vmalloc.c.
|
|
*
|
|
* Leave one empty page between vmalloc'ed areas and
|
|
* the start of the fixmap, and leave one page empty
|
|
* at the top of mem..
|
|
*/
|
|
#ifdef CONFIG_SUPERH32
|
|
#define FIXADDR_TOP (P4SEG - PAGE_SIZE)
|
|
#else
|
|
#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
|
|
#endif
|
|
#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
|
|
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
|
|
|
|
#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE
|
|
|
|
#include <asm-generic/fixmap.h>
|
|
|
|
#endif
|