| /* |
| * 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/page.h> |
| #include <spaces.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 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. |
| */ |
| |
| /* |
| * on UP currently we will have no trace of the fixmap mechanizm, |
| * no page table allocations, etc. This might change in the |
| * future, say framebuffers for the console driver(s) could be |
| * fix-mapped? |
| */ |
| enum fixed_addresses { |
| #define FIX_N_COLOURS 8 |
| FIX_CMAP_BEGIN, |
| FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * 2), |
| #ifdef CONFIG_HIGHMEM |
| /* reserved pte's for temporary kernel mappings */ |
| FIX_KMAP_BEGIN = FIX_CMAP_END + 1, |
| FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, |
| #endif |
| __end_of_fixed_addresses |
| }; |
| |
| /* |
| * used by vmalloc.c. |
| * |
| * Leave one empty page between vmalloc'ed areas and |
| * the start of the fixmap, and leave one page empty |
| * at the top of mem.. |
| */ |
| #define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) |
| #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) |
| |
| #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)) |
| |
| /* |
| * Called from pgtable_init() |
| */ |
| extern void fixrange_init(unsigned long start, unsigned long end, |
| pgd_t *pgd_base); |
| |
| |
| #endif |
