diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-28 08:33:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-28 08:33:25 -0700 |
commit | c32f1a34ff1097110469a240ea4539dc9c101e96 (patch) | |
tree | eda863205e83afe54cbedcf15cdac416cdec2cf5 /arch/sparc/include/asm/fixmap.h | |
parent | 4f31f3080943c7e3541f07df326f06d598a067d0 (diff) | |
parent | 04d91cb8163f7f946e348b2362a6e5dfa5f06b13 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
sparc: Set CONFIG_HAVE_ARCH_TRACEHOOK
sparc: Add task_pt_regs().
sparc: Add call to tracehook_signal_handler().
sparc: Create and use TIF_NOTIFY_RESUME.
sparc: Use tracehook routines in syscall_trace().
sparc64: tracehook: CONFIG_HAVE_ARCH_TRACEHOOK
sparc: Add user_stack_pointer().
sparc64: tracehook_signal_handler
sparc64: tracehook: TIF_NOTIFY_RESUME
sparc: Add asm/syscall.h
sparc64: tracehook syscall
sparc: enable headers_export again
sparc, sparc64: use arch/sparc/include
Diffstat (limited to 'arch/sparc/include/asm/fixmap.h')
-rw-r--r-- | arch/sparc/include/asm/fixmap.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/fixmap.h b/arch/sparc/include/asm/fixmap.h new file mode 100644 index 00000000000..f18fc0755ad --- /dev/null +++ b/arch/sparc/include/asm/fixmap.h @@ -0,0 +1,110 @@ +/* + * 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 <asm/page.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 top of unused virtual memory (0xfd000000 - 1 page) 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 mechanism, + * 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 { + FIX_HOLE, +#ifdef CONFIG_HIGHMEM + FIX_KMAP_BEGIN, + FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, +#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) +/* + * used by vmalloc.c. + * + * Leave one empty page between IO pages at 0xfd000000 and + * the start of the fixmap. + */ +#define FIXADDR_TOP (0xfcfff000UL) +#define FIXADDR_SIZE ((__end_of_fixed_addresses) << PAGE_SHIFT) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + +#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) + +extern void __this_fixmap_does_not_exist(void); + +/* + * 'index to address' translation. If anyone tries to use the idx + * directly without tranlation, we catch the bug with a NULL-deference + * kernel oops. Illegal ranges of incoming indices are caught too. + */ +static 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); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} + +#endif |