c3e0af9879
This reverts commit 20e7c297ef.
With store queues enabled the area above P4SEG has special properties
from the MMU's point of view, which was causing fixmap failure. We'll
have to do something else to satisfy the vmalloc range check.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
136 lines
4.1 KiB
C
136 lines
4.1 KiB
C
/*
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* fixmap.h: compile-time virtual memory allocation
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1998 Ingo Molnar
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*
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* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
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*/
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#ifndef _ASM_FIXMAP_H
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#define _ASM_FIXMAP_H
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#include <linux/kernel.h>
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#include <linux/threads.h>
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#include <asm/page.h>
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#ifdef CONFIG_HIGHMEM
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#include <asm/kmap_types.h>
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#endif
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/*
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* Here we define all the compile-time 'special' virtual
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* addresses. The point is to have a constant address at
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* compile time, but to set the physical address only
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* in the boot process. We allocate these special addresses
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* from the end of P3 backwards.
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* Also this lets us do fail-safe vmalloc(), we
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* can guarantee that these special addresses and
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* vmalloc()-ed addresses never overlap.
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*
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* these 'compile-time allocated' memory buffers are
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* fixed-size 4k pages. (or larger if used with an increment
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* highger than 1) use fixmap_set(idx,phys) to associate
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* physical memory with fixmap indices.
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*
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* TLB entries of such buffers will not be flushed across
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* task switches.
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*/
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/*
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* on UP currently we will have no trace of the fixmap mechanizm,
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* no page table allocations, etc. This might change in the
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* future, say framebuffers for the console driver(s) could be
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* fix-mapped?
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*/
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enum fixed_addresses {
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/*
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* The FIX_CMAP entries are used by kmap_coherent() to get virtual
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* addresses which are of a known color, and so their values are
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* important. __fix_to_virt(FIX_CMAP_END - n) must give an address
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* which is the same color as a page (n<<PAGE_SHIFT).
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*/
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#define FIX_N_COLOURS 8
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FIX_CMAP_BEGIN,
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FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS) - 1,
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#ifdef CONFIG_HIGHMEM
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FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
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FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,
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#endif
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#ifdef CONFIG_IOREMAP_FIXED
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/*
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* FIX_IOREMAP entries are useful for mapping physical address
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* space before ioremap() is useable, e.g. really early in boot
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* before kmalloc() is working.
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*/
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#define FIX_N_IOREMAPS 32
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FIX_IOREMAP_BEGIN,
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FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1,
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#endif
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__end_of_fixed_addresses
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};
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extern void __set_fixmap(enum fixed_addresses idx,
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unsigned long phys, pgprot_t flags);
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extern void __clear_fixmap(enum fixed_addresses idx, pgprot_t flags);
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#define set_fixmap(idx, phys) \
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__set_fixmap(idx, phys, PAGE_KERNEL)
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/*
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* Some hardware wants to get fixmapped without caching.
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*/
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#define set_fixmap_nocache(idx, phys) \
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__set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
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/*
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* used by vmalloc.c.
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*
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* Leave one empty page between vmalloc'ed areas and
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* the start of the fixmap, and leave one page empty
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* at the top of mem..
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*/
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#ifdef CONFIG_SUPERH32
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#define FIXADDR_TOP (P4SEG - PAGE_SIZE)
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#else
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#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
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#endif
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#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
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#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
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#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
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#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
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extern void __this_fixmap_does_not_exist(void);
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/*
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* 'index to address' translation. If anyone tries to use the idx
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* directly without tranlation, we catch the bug with a NULL-deference
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* kernel oops. Illegal ranges of incoming indices are caught too.
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*/
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static inline unsigned long fix_to_virt(const unsigned int idx)
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{
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/*
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* this branch gets completely eliminated after inlining,
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* except when someone tries to use fixaddr indices in an
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* illegal way. (such as mixing up address types or using
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* out-of-range indices).
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*
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* If it doesn't get removed, the linker will complain
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* loudly with a reasonably clear error message..
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*/
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if (idx >= __end_of_fixed_addresses)
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__this_fixmap_does_not_exist();
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return __fix_to_virt(idx);
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}
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static inline unsigned long virt_to_fix(const unsigned long vaddr)
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{
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BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
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return __virt_to_fix(vaddr);
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}
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#endif
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