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

https://github.com/aicjofs/android_kernel_lge_v500_20d_f2fs
C Header | 109 lines | 46 code | 14 blank | 49 comment | 2 complexity | 8fb75dd611e70e3b3e4d7f78a55c27b2 MD5 | raw file
  1/*
  2 * fixmap.h: compile-time virtual memory allocation
  3 *
  4 * This file is subject to the terms and conditions of the GNU General Public
  5 * License.  See the file "COPYING" in the main directory of this archive
  6 * for more details.
  7 *
  8 * Copyright (C) 1998 Ingo Molnar
  9 *
 10 * Copyright 2008 Freescale Semiconductor Inc.
 11 *   Port to powerpc added by Kumar Gala
 12 */
 13
 14#ifndef _ASM_FIXMAP_H
 15#define _ASM_FIXMAP_H
 16
 17#ifndef __ASSEMBLY__
 18#include <linux/kernel.h>
 19#include <asm/page.h>
 20#ifdef CONFIG_HIGHMEM
 21#include <linux/threads.h>
 22#include <asm/kmap_types.h>
 23#endif
 24
 25#define FIXADDR_TOP	((unsigned long)(-PAGE_SIZE))
 26
 27/*
 28 * Here we define all the compile-time 'special' virtual
 29 * addresses. The point is to have a constant address at
 30 * compile time, but to set the physical address only
 31 * in the boot process. We allocate these special addresses
 32 * from the end of virtual memory (0xfffff000) backwards.
 33 * Also this lets us do fail-safe vmalloc(), we
 34 * can guarantee that these special addresses and
 35 * vmalloc()-ed addresses never overlap.
 36 *
 37 * these 'compile-time allocated' memory buffers are
 38 * fixed-size 4k pages. (or larger if used with an increment
 39 * highger than 1) use fixmap_set(idx,phys) to associate
 40 * physical memory with fixmap indices.
 41 *
 42 * TLB entries of such buffers will not be flushed across
 43 * task switches.
 44 */
 45enum fixed_addresses {
 46	FIX_HOLE,
 47	/* reserve the top 128K for early debugging purposes */
 48	FIX_EARLY_DEBUG_TOP = FIX_HOLE,
 49	FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+((128*1024)/PAGE_SIZE)-1,
 50#ifdef CONFIG_HIGHMEM
 51	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
 52	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
 53#endif
 54	/* FIX_PCIE_MCFG, */
 55	__end_of_fixed_addresses
 56};
 57
 58extern void __set_fixmap (enum fixed_addresses idx,
 59					phys_addr_t phys, pgprot_t flags);
 60
 61#define set_fixmap(idx, phys) \
 62		__set_fixmap(idx, phys, PAGE_KERNEL)
 63/*
 64 * Some hardware wants to get fixmapped without caching.
 65 */
 66#define set_fixmap_nocache(idx, phys) \
 67		__set_fixmap(idx, phys, PAGE_KERNEL_NCG)
 68
 69#define clear_fixmap(idx) \
 70		__set_fixmap(idx, 0, __pgprot(0))
 71
 72#define __FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
 73#define FIXADDR_START		(FIXADDR_TOP - __FIXADDR_SIZE)
 74
 75#define __fix_to_virt(x)	(FIXADDR_TOP - ((x) << PAGE_SHIFT))
 76#define __virt_to_fix(x)	((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
 77
 78extern void __this_fixmap_does_not_exist(void);
 79
 80/*
 81 * 'index to address' translation. If anyone tries to use the idx
 82 * directly without tranlation, we catch the bug with a NULL-deference
 83 * kernel oops. Illegal ranges of incoming indices are caught too.
 84 */
 85static __always_inline unsigned long fix_to_virt(const unsigned int idx)
 86{
 87	/*
 88	 * this branch gets completely eliminated after inlining,
 89	 * except when someone tries to use fixaddr indices in an
 90	 * illegal way. (such as mixing up address types or using
 91	 * out-of-range indices).
 92	 *
 93	 * If it doesn't get removed, the linker will complain
 94	 * loudly with a reasonably clear error message..
 95	 */
 96	if (idx >= __end_of_fixed_addresses)
 97		__this_fixmap_does_not_exist();
 98
 99        return __fix_to_virt(idx);
100}
101
102static inline unsigned long virt_to_fix(const unsigned long vaddr)
103{
104	BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
105	return __virt_to_fix(vaddr);
106}
107
108#endif /* !__ASSEMBLY__ */
109#endif