d6dd61c831
Add hooks to allow a paravirt implementation to track the lifetime of an mm. Paravirtualization requires three hooks, but only two are needed in common code. They are: arch_dup_mmap, which is called when a new mmap is created at fork arch_exit_mmap, which is called when the last process reference to an mm is dropped, which typically happens on exit and exec. The third hook is activate_mm, which is called from the arch-specific activate_mm() macro/function, and so doesn't need stub versions for other architectures. It's called when an mm is first used. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: linux-arch@vger.kernel.org Cc: James Bottomley <James.Bottomley@SteelEye.com> Acked-by: Ingo Molnar <mingo@elte.hu>
75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
#ifndef __PARISC_MMU_CONTEXT_H
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#define __PARISC_MMU_CONTEXT_H
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#include <linux/mm.h>
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#include <asm/atomic.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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#include <asm-generic/mm_hooks.h>
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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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}
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/* on PA-RISC, we actually have enough contexts to justify an allocator
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* for them. prumpf */
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extern unsigned long alloc_sid(void);
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extern void free_sid(unsigned long);
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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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BUG_ON(atomic_read(&mm->mm_users) != 1);
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mm->context = alloc_sid();
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return 0;
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}
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static inline void
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destroy_context(struct mm_struct *mm)
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{
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free_sid(mm->context);
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mm->context = 0;
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}
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static inline void load_context(mm_context_t context)
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{
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mtsp(context, 3);
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#if SPACEID_SHIFT == 0
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mtctl(context << 1,8);
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#else
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mtctl(context >> (SPACEID_SHIFT - 1),8);
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#endif
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}
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static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk)
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{
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if (prev != next) {
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mtctl(__pa(next->pgd), 25);
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load_context(next->context);
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}
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}
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#define deactivate_mm(tsk,mm) do { } while (0)
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static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
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{
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/*
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* Activate_mm is our one chance to allocate a space id
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* for a new mm created in the exec path. There's also
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* some lazy tlb stuff, which is currently dead code, but
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* we only allocate a space id if one hasn't been allocated
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* already, so we should be OK.
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*/
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BUG_ON(next == &init_mm); /* Should never happen */
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if (next->context == 0)
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next->context = alloc_sid();
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switch_mm(prev,next,current);
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}
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#endif
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