1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
207 lines
4.9 KiB
C
207 lines
4.9 KiB
C
/*
|
|
* Copyright (C) 1999 Niibe Yutaka
|
|
* Copyright (C) 2003 Paul Mundt
|
|
*
|
|
* ASID handling idea taken from MIPS implementation.
|
|
*/
|
|
#ifndef __ASM_SH_MMU_CONTEXT_H
|
|
#define __ASM_SH_MMU_CONTEXT_H
|
|
#ifdef __KERNEL__
|
|
|
|
#include <asm/cpu/mmu_context.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/io.h>
|
|
|
|
/*
|
|
* The MMU "context" consists of two things:
|
|
* (a) TLB cache version (or round, cycle whatever expression you like)
|
|
* (b) ASID (Address Space IDentifier)
|
|
*/
|
|
|
|
/*
|
|
* Cache of MMU context last used.
|
|
*/
|
|
extern unsigned long mmu_context_cache;
|
|
|
|
#define MMU_CONTEXT_ASID_MASK 0x000000ff
|
|
#define MMU_CONTEXT_VERSION_MASK 0xffffff00
|
|
#define MMU_CONTEXT_FIRST_VERSION 0x00000100
|
|
#define NO_CONTEXT 0
|
|
|
|
/* ASID is 8-bit value, so it can't be 0x100 */
|
|
#define MMU_NO_ASID 0x100
|
|
|
|
/*
|
|
* Virtual Page Number mask
|
|
*/
|
|
#define MMU_VPN_MASK 0xfffff000
|
|
|
|
#ifdef CONFIG_MMU
|
|
/*
|
|
* Get MMU context if needed.
|
|
*/
|
|
static __inline__ void
|
|
get_mmu_context(struct mm_struct *mm)
|
|
{
|
|
extern void flush_tlb_all(void);
|
|
unsigned long mc = mmu_context_cache;
|
|
|
|
/* Check if we have old version of context. */
|
|
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 exhaust ASID of this version.
|
|
* Flush all TLB and start new cycle.
|
|
*/
|
|
flush_tlb_all();
|
|
/*
|
|
* Fix version; Note that we avoid version #0
|
|
* to distingush 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)
|
|
{
|
|
unsigned long __dummy;
|
|
|
|
__asm__ __volatile__ ("mov.l %2, %0\n\t"
|
|
"and %3, %0\n\t"
|
|
"or %1, %0\n\t"
|
|
"mov.l %0, %2"
|
|
: "=&r" (__dummy)
|
|
: "r" (asid), "m" (__m(MMU_PTEH)),
|
|
"r" (0xffffff00));
|
|
}
|
|
|
|
static __inline__ unsigned long get_asid(void)
|
|
{
|
|
unsigned long asid;
|
|
|
|
__asm__ __volatile__ ("mov.l %1, %0"
|
|
: "=r" (asid)
|
|
: "m" (__m(MMU_PTEH)));
|
|
asid &= MMU_CONTEXT_ASID_MASK;
|
|
return asid;
|
|
}
|
|
|
|
/*
|
|
* After we have set current->mm to a new value, this activates
|
|
* the context for the new mm so we see the new mappings.
|
|
*/
|
|
static __inline__ void activate_context(struct mm_struct *mm)
|
|
{
|
|
get_mmu_context(mm);
|
|
set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
|
|
}
|
|
|
|
/* MMU_TTB can be used for optimizing the fault handling.
|
|
(Currently not used) */
|
|
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;
|
|
|
|
__asm__ __volatile__("mov.l %0, %1"
|
|
: /* no output */
|
|
: "r" (__pgdir), "m" (__m(MMU_TTB)));
|
|
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)
|
|
{
|
|
}
|
|
#else /* !CONFIG_MMU */
|
|
#define get_mmu_context(mm) do { } while (0)
|
|
#define init_new_context(tsk,mm) (0)
|
|
#define destroy_context(mm) do { } while (0)
|
|
#define set_asid(asid) do { } while (0)
|
|
#define get_asid() (0)
|
|
#define activate_context(mm) do { } while (0)
|
|
#define switch_mm(prev,next,tsk) do { } while (0)
|
|
#define deactivate_mm(tsk,mm) do { } while (0)
|
|
#define activate_mm(prev,next) do { } while (0)
|
|
#define enter_lazy_tlb(mm,tsk) do { } while (0)
|
|
#endif /* CONFIG_MMU */
|
|
|
|
#if defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
|
|
/*
|
|
* If this processor has an MMU, we need methods to turn it off/on ..
|
|
* paging_init() will also have to be updated for the processor in
|
|
* question.
|
|
*/
|
|
static inline void enable_mmu(void)
|
|
{
|
|
/* Enable MMU */
|
|
ctrl_outl(MMU_CONTROL_INIT, MMUCR);
|
|
|
|
/* The manual suggests doing some nops after turning on the MMU */
|
|
__asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop\n\t");
|
|
|
|
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)
|
|
{
|
|
unsigned long cr;
|
|
|
|
cr = ctrl_inl(MMUCR);
|
|
cr &= ~MMU_CONTROL_INIT;
|
|
ctrl_outl(cr, MMUCR);
|
|
__asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop\n\t");
|
|
}
|
|
#else
|
|
/*
|
|
* MMU control handlers for processors lacking memory
|
|
* management hardware.
|
|
*/
|
|
#define enable_mmu() do { BUG(); } while (0)
|
|
#define disable_mmu() do { BUG(); } while (0)
|
|
#endif
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* __ASM_SH_MMU_CONTEXT_H */
|