100 lines
2.9 KiB
C
100 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
|
|
*/
|
|
|
|
#ifndef _ASM_FIXMAP_64_H
|
|
#define _ASM_FIXMAP_64_H
|
|
|
|
#include <linux/kernel.h>
|
|
#include <asm/apicdef.h>
|
|
#include <asm/page.h>
|
|
#include <asm/vsyscall.h>
|
|
#include <asm/efi.h>
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* These 'compile-time allocated' memory buffers are
|
|
* fixed-size 4k pages (or larger if used with an increment
|
|
* higher than 1). Use set_fixmap(idx,phys) to associate
|
|
* physical memory with fixmap indices.
|
|
*
|
|
* TLB entries of such buffers will not be flushed across
|
|
* task switches.
|
|
*/
|
|
|
|
enum fixed_addresses {
|
|
VSYSCALL_LAST_PAGE,
|
|
VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE
|
|
+ ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
|
|
VSYSCALL_HPET,
|
|
FIX_DBGP_BASE,
|
|
FIX_EARLYCON_MEM_BASE,
|
|
FIX_HPET_BASE,
|
|
FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
|
|
FIX_IO_APIC_BASE_0,
|
|
FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
|
|
FIX_EFI_IO_MAP_LAST_PAGE,
|
|
FIX_EFI_IO_MAP_FIRST_PAGE = FIX_EFI_IO_MAP_LAST_PAGE
|
|
+ MAX_EFI_IO_PAGES - 1,
|
|
#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
|
|
FIX_OHCI1394_BASE,
|
|
#endif
|
|
__end_of_fixed_addresses
|
|
};
|
|
|
|
extern void __set_fixmap(enum fixed_addresses idx,
|
|
unsigned long phys, pgprot_t flags);
|
|
|
|
#define set_fixmap(idx, phys) \
|
|
__set_fixmap(idx, phys, PAGE_KERNEL)
|
|
/*
|
|
* Some hardware wants to get fixmapped without caching.
|
|
*/
|
|
#define set_fixmap_nocache(idx, phys) \
|
|
__set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
|
|
|
|
#define FIXADDR_TOP (VSYSCALL_END-PAGE_SIZE)
|
|
#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
|
|
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
|
|
|
|
/* Only covers 32bit vsyscalls currently. Need another set for 64bit. */
|
|
#define FIXADDR_USER_START ((unsigned long)VSYSCALL32_VSYSCALL)
|
|
#define FIXADDR_USER_END (FIXADDR_USER_START + PAGE_SIZE)
|
|
|
|
#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
|
|
|
|
extern void __this_fixmap_does_not_exist(void);
|
|
|
|
/*
|
|
* '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)
|
|
{
|
|
/*
|
|
* this branch gets completely eliminated after inlining,
|
|
* except when someone tries to use fixaddr indices in an
|
|
* illegal way. (such as mixing up address types or using
|
|
* out-of-range indices).
|
|
*
|
|
* If it doesn't get removed, the linker will complain
|
|
* loudly with a reasonably clear error message..
|
|
*/
|
|
if (idx >= __end_of_fixed_addresses)
|
|
__this_fixmap_does_not_exist();
|
|
|
|
return __fix_to_virt(idx);
|
|
}
|
|
|
|
#endif
|