367b8112fe
Move all header files for xtensa to arch/xtensa/include and platform and variant header files to the appropriate arch/xtensa/platforms/ and arch/xtensa/variants/ directories. Moving the files gets also rid of all uses of symlinks in the Makefile. This has been completed already for the majority of the architectures and xtensa is one out of six missing. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Chris Zankel <chris@zankel.net>
136 lines
2.9 KiB
C
136 lines
2.9 KiB
C
/*
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* include/asm-xtensa/mmu_context.h
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*
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* Switch an MMU context.
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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) 2001 - 2005 Tensilica Inc.
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*/
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#ifndef _XTENSA_MMU_CONTEXT_H
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#define _XTENSA_MMU_CONTEXT_H
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#include <linux/stringify.h>
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#include <linux/sched.h>
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#include <asm/pgtable.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm-generic/mm_hooks.h>
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#define XCHAL_MMU_ASID_BITS 8
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#if (XCHAL_HAVE_TLBS != 1)
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# error "Linux must have an MMU!"
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#endif
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extern unsigned long asid_cache;
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/*
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* NO_CONTEXT is the invalid ASID value that we don't ever assign to
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* any user or kernel context.
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*
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* 0 invalid
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* 1 kernel
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* 2 reserved
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* 3 reserved
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* 4...255 available
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*/
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#define NO_CONTEXT 0
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#define ASID_USER_FIRST 4
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#define ASID_MASK ((1 << XCHAL_MMU_ASID_BITS) - 1)
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#define ASID_INSERT(x) (0x03020001 | (((x) & ASID_MASK) << 8))
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static inline void set_rasid_register (unsigned long val)
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{
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__asm__ __volatile__ (" wsr %0, "__stringify(RASID)"\n\t"
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" isync\n" : : "a" (val));
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}
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static inline unsigned long get_rasid_register (void)
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{
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unsigned long tmp;
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__asm__ __volatile__ (" rsr %0,"__stringify(RASID)"\n\t" : "=a" (tmp));
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return tmp;
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}
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static inline void
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__get_new_mmu_context(struct mm_struct *mm)
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{
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extern void flush_tlb_all(void);
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if (! (++asid_cache & ASID_MASK) ) {
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flush_tlb_all(); /* start new asid cycle */
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asid_cache += ASID_USER_FIRST;
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}
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mm->context = asid_cache;
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}
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static inline void
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__load_mmu_context(struct mm_struct *mm)
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{
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set_rasid_register(ASID_INSERT(mm->context));
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invalidate_page_directory();
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}
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/*
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* Initialize the context related info for a new mm_struct
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* instance.
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*/
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static inline int
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init_new_context(struct task_struct *tsk, struct mm_struct *mm)
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{
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mm->context = NO_CONTEXT;
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return 0;
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}
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/*
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* After we have set current->mm to a new value, this activates
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* the context for the new mm so we see the new mappings.
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*/
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static inline void
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activate_mm(struct mm_struct *prev, struct mm_struct *next)
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{
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/* Unconditionally get a new ASID. */
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__get_new_mmu_context(next);
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__load_mmu_context(next);
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}
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static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
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struct task_struct *tsk)
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{
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unsigned long asid = asid_cache;
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/* Check if our ASID is of an older version and thus invalid */
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if (next->context == NO_CONTEXT || ((next->context^asid) & ~ASID_MASK))
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__get_new_mmu_context(next);
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__load_mmu_context(next);
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}
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#define deactivate_mm(tsk, mm) do { } while(0)
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/*
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* Destroy context related info for an mm_struct that is about
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* to be put to rest.
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*/
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static inline void destroy_context(struct mm_struct *mm)
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{
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invalidate_page_directory();
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}
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static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
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{
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/* Nothing to do. */
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}
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#endif /* _XTENSA_MMU_CONTEXT_H */
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