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fd94093435
Impact: introduce new APIs, separate kmap code from CONFIG_HIGHMEM This takes the code used for CONFIG_HIGHMEM memory mappings except that it's designed for dynamic IO resource mapping. These fixmaps are available even with CONFIG_HIGHMEM turned off. Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
73 lines
1.9 KiB
C
73 lines
1.9 KiB
C
#ifndef _ASM_X86_FIXMAP_H
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#define _ASM_X86_FIXMAP_H
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#ifdef CONFIG_X86_32
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# include "fixmap_32.h"
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#else
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# include "fixmap_64.h"
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#endif
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extern int fixmaps_set;
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extern pte_t *kmap_pte;
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extern pgprot_t kmap_prot;
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extern pte_t *pkmap_page_table;
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void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
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void native_set_fixmap(enum fixed_addresses idx,
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unsigned long phys, pgprot_t flags);
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#ifndef CONFIG_PARAVIRT
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static inline void __set_fixmap(enum fixed_addresses idx,
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unsigned long phys, pgprot_t flags)
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{
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native_set_fixmap(idx, phys, flags);
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}
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#endif
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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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#define clear_fixmap(idx) \
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__set_fixmap(idx, 0, __pgprot(0))
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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 translation, 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 __always_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 /* _ASM_X86_FIXMAP_H */
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