e5e3a04289
This patch removes the default_ldt[] array, as it has been unused since iBCS stopped being supported. This means it is now possible to actually set an empty LDT segment. In order to deal with this, the set_ldt_desc/load_LDT pair has been replaced with a single set_ldt() operation which is responsible for both setting up the LDT descriptor in the GDT, and reloading the LDT register. If there are no LDT entries, the LDT register is loaded with a NULL descriptor. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Acked-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
71 lines
1.7 KiB
C
71 lines
1.7 KiB
C
#ifndef __I386_SCHED_H
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#define __I386_SCHED_H
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#include <asm/desc.h>
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#include <asm/atomic.h>
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#include <asm/pgalloc.h>
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#include <asm/tlbflush.h>
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/*
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* Used for LDT copy/destruction.
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*/
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int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
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void destroy_context(struct mm_struct *mm);
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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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#ifdef CONFIG_SMP
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unsigned cpu = smp_processor_id();
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if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK)
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per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_LAZY;
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#endif
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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,
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struct task_struct *tsk)
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{
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int cpu = smp_processor_id();
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if (likely(prev != next)) {
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/* stop flush ipis for the previous mm */
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cpu_clear(cpu, prev->cpu_vm_mask);
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#ifdef CONFIG_SMP
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per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
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per_cpu(cpu_tlbstate, cpu).active_mm = next;
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#endif
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cpu_set(cpu, next->cpu_vm_mask);
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/* Re-load page tables */
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load_cr3(next->pgd);
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/*
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* load the LDT, if the LDT is different:
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*/
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if (unlikely(prev->context.ldt != next->context.ldt))
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load_LDT_nolock(&next->context);
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}
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#ifdef CONFIG_SMP
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else {
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per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
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BUG_ON(per_cpu(cpu_tlbstate, cpu).active_mm != next);
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if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
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/* We were in lazy tlb mode and leave_mm disabled
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* tlb flush IPI delivery. We must reload %cr3.
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*/
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load_cr3(next->pgd);
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load_LDT_nolock(&next->context);
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}
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}
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#endif
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}
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#define deactivate_mm(tsk, mm) \
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asm("movl %0,%%fs ; movl %0,%%gs": :"r" (0))
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#define activate_mm(prev, next) \
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switch_mm((prev),(next),NULL)
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#endif
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