linux/arch/powerpc/include/asm/fixmap.h

70 lines
2.0 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
*
* Copyright 2008 Freescale Semiconductor Inc.
* Port to powerpc added by Kumar Gala
*/
#ifndef _ASM_FIXMAP_H
#define _ASM_FIXMAP_H
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <asm/page.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#endif
#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
/*
* 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 virtual memory (0xfffff000) 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.
*/
enum fixed_addresses {
FIX_HOLE,
/* reserve the top 128K for early debugging purposes */
FIX_EARLY_DEBUG_TOP = FIX_HOLE,
FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+((128*1024)/PAGE_SIZE)-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
/* FIX_PCIE_MCFG, */
__end_of_fixed_addresses
};
extern void __set_fixmap (enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags);
#define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
#include <asm-generic/fixmap.h>
#endif /* !__ASSEMBLY__ */
#endif