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![Jeremy Fitzhardinge](/assets/img/avatar_default.png)
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>
72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
/*
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* include/asm-s390/mmu_context.h
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*
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* S390 version
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*
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* Derived from "include/asm-i386/mmu_context.h"
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*/
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#ifndef __S390_MMU_CONTEXT_H
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#define __S390_MMU_CONTEXT_H
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#include <asm/pgalloc.h>
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#include <asm-generic/mm_hooks.h>
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/*
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* get a new mmu context.. S390 don't know about contexts.
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*/
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#define init_new_context(tsk,mm) 0
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#define destroy_context(mm) do { } while (0)
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#ifndef __s390x__
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#define LCTL_OPCODE "lctl"
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#define PGTABLE_BITS (_SEGMENT_TABLE|USER_STD_MASK)
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#else
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#define LCTL_OPCODE "lctlg"
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#define PGTABLE_BITS (_REGION_TABLE|USER_STD_MASK)
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#endif
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static inline void enter_lazy_tlb(struct mm_struct *mm,
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struct task_struct *tsk)
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{
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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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pgd_t *shadow_pgd = get_shadow_pgd(next->pgd);
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if (prev != next) {
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S390_lowcore.user_asce = (__pa(next->pgd) & PAGE_MASK) |
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PGTABLE_BITS;
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if (shadow_pgd) {
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/* Load primary/secondary space page table origin. */
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S390_lowcore.user_exec_asce =
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(__pa(shadow_pgd) & PAGE_MASK) | PGTABLE_BITS;
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asm volatile(LCTL_OPCODE" 1,1,%0\n"
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LCTL_OPCODE" 7,7,%1"
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: : "m" (S390_lowcore.user_exec_asce),
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"m" (S390_lowcore.user_asce) );
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} else if (switch_amode) {
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/* Load primary space page table origin. */
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asm volatile(LCTL_OPCODE" 1,1,%0"
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: : "m" (S390_lowcore.user_asce) );
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} else
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/* Load home space page table origin. */
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asm volatile(LCTL_OPCODE" 13,13,%0"
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: : "m" (S390_lowcore.user_asce) );
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}
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cpu_set(smp_processor_id(), next->cpu_vm_mask);
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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,
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struct mm_struct *next)
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{
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switch_mm(prev, next, current);
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set_fs(current->thread.mm_segment);
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}
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#endif /* __S390_MMU_CONTEXT_H */
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