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Diffstat (limited to 'arch/xtensa/include/asm/fixmap.h')
-rw-r--r-- | arch/xtensa/include/asm/fixmap.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/fixmap.h b/arch/xtensa/include/asm/fixmap.h new file mode 100644 index 000000000000..9f6c33d0428a --- /dev/null +++ b/arch/xtensa/include/asm/fixmap.h @@ -0,0 +1,58 @@ +/* + * 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 end of the consistent memory region 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 + * 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) - 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) + +#include <asm-generic/fixmap.h> + +#define kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel( \ + pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), \ + (vaddr) \ + ) + +#endif |