kernel-ark/include/asm-x86_64/mmu_context.h
Jeremy Fitzhardinge d6dd61c831 [PATCH] x86: PARAVIRT: add hooks to intercept mm creation and destruction
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>
2007-05-02 19:27:14 +02:00

75 lines
1.8 KiB
C

#ifndef __X86_64_MMU_CONTEXT_H
#define __X86_64_MMU_CONTEXT_H
#include <asm/desc.h>
#include <asm/atomic.h>
#include <asm/pgalloc.h>
#include <asm/pda.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm-generic/mm_hooks.h>
/*
* possibly do the LDT unload here?
*/
int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
void destroy_context(struct mm_struct *mm);
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
#ifdef CONFIG_SMP
if (read_pda(mmu_state) == TLBSTATE_OK)
write_pda(mmu_state, TLBSTATE_LAZY);
#endif
}
static inline void load_cr3(pgd_t *pgd)
{
asm volatile("movq %0,%%cr3" :: "r" (__pa(pgd)) : "memory");
}
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
unsigned cpu = smp_processor_id();
if (likely(prev != next)) {
/* stop flush ipis for the previous mm */
cpu_clear(cpu, prev->cpu_vm_mask);
#ifdef CONFIG_SMP
write_pda(mmu_state, TLBSTATE_OK);
write_pda(active_mm, next);
#endif
cpu_set(cpu, next->cpu_vm_mask);
load_cr3(next->pgd);
if (unlikely(next->context.ldt != prev->context.ldt))
load_LDT_nolock(&next->context, cpu);
}
#ifdef CONFIG_SMP
else {
write_pda(mmu_state, TLBSTATE_OK);
if (read_pda(active_mm) != next)
out_of_line_bug();
if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
/* We were in lazy tlb mode and leave_mm disabled
* tlb flush IPI delivery. We must reload CR3
* to make sure to use no freed page tables.
*/
load_cr3(next->pgd);
load_LDT_nolock(&next->context, cpu);
}
}
#endif
}
#define deactivate_mm(tsk,mm) do { \
load_gs_index(0); \
asm volatile("movl %0,%%fs"::"r"(0)); \
} while(0)
#define activate_mm(prev, next) \
switch_mm((prev),(next),NULL)
#endif