linux/arch/score/include/asm/mmu_context.h

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#ifndef _ASM_SCORE_MMU_CONTEXT_H
#define _ASM_SCORE_MMU_CONTEXT_H
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <asm-generic/mm_hooks.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/scoreregs.h>
/*
* For the fast tlb miss handlers, we keep a per cpu array of pointers
* to the current pgd for each processor. Also, the proc. id is stuffed
* into the context register.
*/
extern unsigned long asid_cache;
extern unsigned long pgd_current;
#define TLBMISS_HANDLER_SETUP_PGD(pgd) (pgd_current = (unsigned long)(pgd))
#define TLBMISS_HANDLER_SETUP() \
do { \
write_c0_context(0); \
TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir) \
} while (0)
/*
* All unused by hardware upper bits will be considered
* as a software asid extension.
*/
#define ASID_VERSION_MASK 0xfffff000
#define ASID_FIRST_VERSION 0x1000
/* PEVN --------- VPN ---------- --ASID--- -NA- */
/* binary: 0000 0000 0000 0000 0000 0000 0001 0000 */
/* binary: 0000 0000 0000 0000 0000 1111 1111 0000 */
#define ASID_INC 0x10
#define ASID_MASK 0xff0
static inline void enter_lazy_tlb(struct mm_struct *mm,
struct task_struct *tsk)
{}
static inline void
get_new_mmu_context(struct mm_struct *mm)
{
unsigned long asid = asid_cache + ASID_INC;
if (!(asid & ASID_MASK)) {
local_flush_tlb_all(); /* start new asid cycle */
if (!asid) /* fix version if needed */
asid = ASID_FIRST_VERSION;
}
mm->context = asid;
asid_cache = asid;
}
/*
* 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 = 0;
return 0;
}
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
unsigned long flags;
local_irq_save(flags);
if ((next->context ^ asid_cache) & ASID_VERSION_MASK)
get_new_mmu_context(next);
pevn_set(next->context);
TLBMISS_HANDLER_SETUP_PGD(next->pgd);
local_irq_restore(flags);
}
/*
* 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)
{}
static inline void
deactivate_mm(struct task_struct *task, struct mm_struct *mm)
{}
/*
* 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_mm(struct mm_struct *prev, struct mm_struct *next)
{
unsigned long flags;
local_irq_save(flags);
get_new_mmu_context(next);
pevn_set(next->context);
TLBMISS_HANDLER_SETUP_PGD(next->pgd);
local_irq_restore(flags);
}
#endif /* _ASM_SCORE_MMU_CONTEXT_H */