80 lines
2.3 KiB
C
80 lines
2.3 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 <asm/pgtable.h>
|
|
#ifdef CONFIG_HIGHMEM
|
|
#include <linux/threads.h>
|
|
#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 start of the consistent memory region upwards.
|
|
* 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
|
|
* higher than 1) use fixmap_set(idx,phys) to associate
|
|
* physical memory with fixmap indices.
|
|
*/
|
|
enum fixed_addresses {
|
|
#ifdef CONFIG_HIGHMEM
|
|
/* reserved pte's for temporary kernel mappings */
|
|
FIX_KMAP_BEGIN,
|
|
FIX_KMAP_END = FIX_KMAP_BEGIN +
|
|
(KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1,
|
|
#endif
|
|
__end_of_fixed_addresses
|
|
};
|
|
|
|
#define FIXADDR_TOP (VMALLOC_START - PAGE_SIZE)
|
|
#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
|
|
#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK)
|
|
|
|
#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT))
|
|
#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT)
|
|
|
|
#ifndef __ASSEMBLY__
|
|
/*
|
|
* 'index to address' translation. If anyone tries to use the idx
|
|
* directly without translation, we catch the bug with a NULL-deference
|
|
* kernel oops. Illegal ranges of incoming indices are caught too.
|
|
*/
|
|
static __always_inline unsigned long fix_to_virt(const unsigned int idx)
|
|
{
|
|
BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
|
|
return __fix_to_virt(idx);
|
|
}
|
|
|
|
static inline unsigned long virt_to_fix(const unsigned long vaddr)
|
|
{
|
|
BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
|
|
return __virt_to_fix(vaddr);
|
|
}
|
|
|
|
#endif
|
|
|
|
#define kmap_get_fixmap_pte(vaddr) \
|
|
pte_offset_kernel( \
|
|
pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), \
|
|
(vaddr) \
|
|
)
|
|
|
|
#endif
|