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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/sh/include/asm/fixmap.h |
Initial import
Diffstat (limited to 'arch/sh/include/asm/fixmap.h')
-rw-r--r-- | arch/sh/include/asm/fixmap.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/arch/sh/include/asm/fixmap.h b/arch/sh/include/asm/fixmap.h new file mode 100644 index 000000000..4daf91c3b --- /dev/null +++ b/arch/sh/include/asm/fixmap.h @@ -0,0 +1,101 @@ +/* + * 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 <linux/kernel.h> +#include <linux/threads.h> +#include <asm/page.h> +#ifdef CONFIG_HIGHMEM +#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 P3 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 { + /* + * The FIX_CMAP entries are used by kmap_coherent() to get virtual + * addresses which are of a known color, and so their values are + * important. __fix_to_virt(FIX_CMAP_END - n) must give an address + * which is the same color as a page (n<<PAGE_SHIFT). + */ +#define FIX_N_COLOURS 8 + FIX_CMAP_BEGIN, + FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS) - 1, + +#ifdef CONFIG_HIGHMEM + FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1, +#endif + +#ifdef CONFIG_IOREMAP_FIXED + /* + * FIX_IOREMAP entries are useful for mapping physical address + * space before ioremap() is useable, e.g. really early in boot + * before kmalloc() is working. + */ +#define FIX_N_IOREMAPS 32 + FIX_IOREMAP_BEGIN, + FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1, +#endif + + __end_of_fixed_addresses +}; + +extern void __set_fixmap(enum fixed_addresses idx, + unsigned long phys, pgprot_t flags); +extern void __clear_fixmap(enum fixed_addresses idx, pgprot_t flags); + +/* + * 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.. + */ +#ifdef CONFIG_SUPERH32 +#define FIXADDR_TOP (P4SEG - PAGE_SIZE) +#else +#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE)) +#endif +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + +#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE + +#include <asm-generic/fixmap.h> + +#endif |