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>
164 lines
4.2 KiB
C
164 lines
4.2 KiB
C
#ifndef _ASM_M32R_MMU_CONTEXT_H
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#define _ASM_M32R_MMU_CONTEXT_H
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#ifdef __KERNEL__
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#include <asm/m32r.h>
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#define MMU_CONTEXT_ASID_MASK (0x000000FF)
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#define MMU_CONTEXT_VERSION_MASK (0xFFFFFF00)
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#define MMU_CONTEXT_FIRST_VERSION (0x00000100)
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#define NO_CONTEXT (0x00000000)
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#ifndef __ASSEMBLY__
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#include <asm/atomic.h>
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#include <asm/pgalloc.h>
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#include <asm/mmu.h>
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#include <asm/tlbflush.h>
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#include <asm-generic/mm_hooks.h>
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/*
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* Cache of MMU context last used.
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*/
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#ifndef CONFIG_SMP
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extern unsigned long mmu_context_cache_dat;
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#define mmu_context_cache mmu_context_cache_dat
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#define mm_context(mm) mm->context
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#else /* not CONFIG_SMP */
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extern unsigned long mmu_context_cache_dat[];
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#define mmu_context_cache mmu_context_cache_dat[smp_processor_id()]
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#define mm_context(mm) mm->context[smp_processor_id()]
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#endif /* not CONFIG_SMP */
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#define set_tlb_tag(entry, tag) (*entry = (tag & PAGE_MASK)|get_asid())
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#define set_tlb_data(entry, data) (*entry = (data | _PAGE_PRESENT))
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#ifdef CONFIG_MMU
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#define enter_lazy_tlb(mm, tsk) do { } while (0)
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static inline void get_new_mmu_context(struct mm_struct *mm)
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{
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unsigned long mc = ++mmu_context_cache;
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if (!(mc & MMU_CONTEXT_ASID_MASK)) {
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/* We exhaust ASID of this version.
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Flush all TLB and start new cycle. */
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local_flush_tlb_all();
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/* Fix version if needed.
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Note that we avoid version #0 to distingush NO_CONTEXT. */
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if (!mc)
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mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
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}
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mm_context(mm) = mc;
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}
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/*
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* Get MMU context if needed.
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*/
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static inline void get_mmu_context(struct mm_struct *mm)
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{
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if (mm) {
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unsigned long mc = mmu_context_cache;
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/* Check if we have old version of context.
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If it's old, we need to get new context with new version. */
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if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
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get_new_mmu_context(mm);
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}
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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 init_new_context(struct task_struct *tsk,
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struct mm_struct *mm)
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{
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#ifndef CONFIG_SMP
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mm->context = NO_CONTEXT;
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#else /* CONFIG_SMP */
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int num_cpus = num_online_cpus();
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int i;
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for (i = 0 ; i < num_cpus ; i++)
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mm->context[i] = NO_CONTEXT;
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#endif /* CONFIG_SMP */
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return 0;
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}
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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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#define destroy_context(mm) do { } while (0)
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static inline void set_asid(unsigned long asid)
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{
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*(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
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}
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static inline unsigned long get_asid(void)
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{
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unsigned long asid;
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asid = *(volatile long *)MASID;
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asid &= MMU_CONTEXT_ASID_MASK;
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return asid;
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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 activate_context(struct mm_struct *mm)
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{
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get_mmu_context(mm);
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set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
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}
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static inline void switch_mm(struct mm_struct *prev,
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struct mm_struct *next, struct task_struct *tsk)
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{
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#ifdef CONFIG_SMP
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int cpu = smp_processor_id();
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#endif /* CONFIG_SMP */
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if (prev != next) {
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#ifdef CONFIG_SMP
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cpu_set(cpu, next->cpu_vm_mask);
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#endif /* CONFIG_SMP */
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/* Set MPTB = next->pgd */
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*(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
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activate_context(next);
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}
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#ifdef CONFIG_SMP
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else
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if (!cpu_test_and_set(cpu, next->cpu_vm_mask))
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activate_context(next);
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#endif /* CONFIG_SMP */
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}
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#define deactivate_mm(tsk, mm) do { } while (0)
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#define activate_mm(prev, next) \
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switch_mm((prev), (next), NULL)
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#else /* not CONFIG_MMU */
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#define get_mmu_context(mm) do { } while (0)
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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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#define set_asid(asid) do { } while (0)
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#define get_asid() (0)
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#define activate_context(mm) do { } while (0)
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#define switch_mm(prev,next,tsk) do { } while (0)
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#define deactivate_mm(mm,tsk) do { } while (0)
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#define activate_mm(prev,next) do { } while (0)
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#define enter_lazy_tlb(mm,tsk) do { } while (0)
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#endif /* not CONFIG_MMU */
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#endif /* not __ASSEMBLY__ */
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#endif /* __KERNEL__ */
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#endif /* _ASM_M32R_MMU_CONTEXT_H */
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