mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 16:24:13 +08:00
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>
150 lines
3.3 KiB
C
150 lines
3.3 KiB
C
/*
|
|
* Copyright (C) 2004-2006 Atmel Corporation
|
|
*
|
|
* ASID handling taken from SH implementation.
|
|
* Copyright (C) 1999 Niibe Yutaka
|
|
* Copyright (C) 2003 Paul Mundt
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#ifndef __ASM_AVR32_MMU_CONTEXT_H
|
|
#define __ASM_AVR32_MMU_CONTEXT_H
|
|
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/sysreg.h>
|
|
#include <asm-generic/mm_hooks.h>
|
|
|
|
/*
|
|
* The MMU "context" consists of two things:
|
|
* (a) TLB cache version
|
|
* (b) ASID (Address Space IDentifier)
|
|
*/
|
|
#define MMU_CONTEXT_ASID_MASK 0x000000ff
|
|
#define MMU_CONTEXT_VERSION_MASK 0xffffff00
|
|
#define MMU_CONTEXT_FIRST_VERSION 0x00000100
|
|
#define NO_CONTEXT 0
|
|
|
|
#define MMU_NO_ASID 0x100
|
|
|
|
/* Virtual Page Number mask */
|
|
#define MMU_VPN_MASK 0xfffff000
|
|
|
|
/* Cache of MMU context last used */
|
|
extern unsigned long mmu_context_cache;
|
|
|
|
/*
|
|
* Get MMU context if needed
|
|
*/
|
|
static inline void
|
|
get_mmu_context(struct mm_struct *mm)
|
|
{
|
|
unsigned long mc = mmu_context_cache;
|
|
|
|
if (((mm->context ^ mc) & MMU_CONTEXT_VERSION_MASK) == 0)
|
|
/* It's up to date, do nothing */
|
|
return;
|
|
|
|
/* It's old, we need to get new context with new version */
|
|
mc = ++mmu_context_cache;
|
|
if (!(mc & MMU_CONTEXT_ASID_MASK)) {
|
|
/*
|
|
* We have exhausted all ASIDs of this version.
|
|
* Flush the TLB and start new cycle.
|
|
*/
|
|
flush_tlb_all();
|
|
/*
|
|
* Fix version. Note that we avoid version #0
|
|
* to distinguish NO_CONTEXT.
|
|
*/
|
|
if (!mc)
|
|
mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
|
|
}
|
|
mm->context = mc;
|
|
}
|
|
|
|
/*
|
|
* Initialize the context related info for a new mm_struct
|
|
* instance.
|
|
*/
|
|
static inline int init_new_context(struct task_struct *tsk,
|
|
struct mm_struct *mm)
|
|
{
|
|
mm->context = NO_CONTEXT;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Destroy context related info for an mm_struct that is about
|
|
* to be put to rest.
|
|
*/
|
|
static inline void destroy_context(struct mm_struct *mm)
|
|
{
|
|
/* Do nothing */
|
|
}
|
|
|
|
static inline void set_asid(unsigned long asid)
|
|
{
|
|
/* XXX: We're destroying TLBEHI[8:31] */
|
|
sysreg_write(TLBEHI, asid & MMU_CONTEXT_ASID_MASK);
|
|
cpu_sync_pipeline();
|
|
}
|
|
|
|
static inline unsigned long get_asid(void)
|
|
{
|
|
unsigned long asid;
|
|
|
|
asid = sysreg_read(TLBEHI);
|
|
return asid & MMU_CONTEXT_ASID_MASK;
|
|
}
|
|
|
|
static inline void activate_context(struct mm_struct *mm)
|
|
{
|
|
get_mmu_context(mm);
|
|
set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
|
|
}
|
|
|
|
static inline void switch_mm(struct mm_struct *prev,
|
|
struct mm_struct *next,
|
|
struct task_struct *tsk)
|
|
{
|
|
if (likely(prev != next)) {
|
|
unsigned long __pgdir = (unsigned long)next->pgd;
|
|
|
|
sysreg_write(PTBR, __pgdir);
|
|
activate_context(next);
|
|
}
|
|
}
|
|
|
|
#define deactivate_mm(tsk,mm) do { } while(0)
|
|
|
|
#define activate_mm(prev, next) switch_mm((prev), (next), NULL)
|
|
|
|
static inline void
|
|
enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
|
|
{
|
|
}
|
|
|
|
|
|
static inline void enable_mmu(void)
|
|
{
|
|
sysreg_write(MMUCR, (SYSREG_BIT(MMUCR_S)
|
|
| SYSREG_BIT(E)
|
|
| SYSREG_BIT(MMUCR_I)));
|
|
nop(); nop(); nop(); nop(); nop(); nop(); nop(); nop();
|
|
|
|
if (mmu_context_cache == NO_CONTEXT)
|
|
mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;
|
|
|
|
set_asid(mmu_context_cache & MMU_CONTEXT_ASID_MASK);
|
|
}
|
|
|
|
static inline void disable_mmu(void)
|
|
{
|
|
sysreg_write(MMUCR, SYSREG_BIT(MMUCR_S));
|
|
}
|
|
|
|
#endif /* __ASM_AVR32_MMU_CONTEXT_H */
|