LXR linux/arch/m32r/include/asm/mmu

   1#ifndef _ASM_M32R_MMU_CONTEXT_H
   2#define _ASM_M32R_MMU_CONTEXT_H
   3#ifdef __KERNEL__
   4
   5#include <asm/m32r.h>
   6
   7#define MMU_CONTEXT_ASID_MASK      (0x000000FF)
   8#define MMU_CONTEXT_VERSION_MASK   (0xFFFFFF00)
   9#define MMU_CONTEXT_FIRST_VERSION  (0x00000100)
  10#define NO_CONTEXT                 (0x00000000)
  11
  12#ifndef __ASSEMBLY__
  13
  14#include <asm/atomic.h>
  15#include <asm/pgalloc.h>
  16#include <asm/mmu.h>
  17#include <asm/tlbflush.h>
  18#include <asm-generic/mm_hooks.h>
  19
  20/*
  21 * Cache of MMU context last used.
  22 */
  23#ifndef CONFIG_SMP
  24extern unsigned long mmu_context_cache_dat;
  25#define mmu_context_cache       mmu_context_cache_dat
  26#define mm_context(mm)          mm->context
  27#else /* not CONFIG_SMP */
  28extern unsigned long mmu_context_cache_dat[];
  29#define mmu_context_cache       mmu_context_cache_dat[smp_processor_id()]
  30#define mm_context(mm)          mm->context[smp_processor_id()]
  31#endif /* not CONFIG_SMP */
  32
  33#define set_tlb_tag(entry, tag)         (*entry = (tag & PAGE_MASK)|get_asid())
  34#define set_tlb_data(entry, data)       (*entry = (data | _PAGE_PRESENT))
  35
  36#ifdef CONFIG_MMU
  37#define enter_lazy_tlb(mm, tsk) do { } while (0)
  38
  39static inline void get_new_mmu_context(struct mm_struct *mm)
  40{
  41        unsigned long mc = ++mmu_context_cache;
  42
  43        if (!(mc & MMU_CONTEXT_ASID_MASK)) {
  44                /* We exhaust ASID of this version.
  45                   Flush all TLB and start new cycle. */
  46                local_flush_tlb_all();
  47                /* Fix version if needed.
  48                   Note that we avoid version #0 to distingush NO_CONTEXT. */
  49                if (!mc)
  50                        mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
  51        }
  52        mm_context(mm) = mc;
  53}
  54
  55/*
  56 * Get MMU context if needed.
  57 */
  58static inline void get_mmu_context(struct mm_struct *mm)
  59{
  60        if (mm) {
  61                unsigned long mc = mmu_context_cache;
  62
  63                /* Check if we have old version of context.
  64                   If it's old, we need to get new context with new version. */
  65                if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
  66                        get_new_mmu_context(mm);
  67        }
  68}
  69
  70/*
  71 * Initialize the context related info for a new mm_struct
  72 * instance.
  73 */
  74static inline int init_new_context(struct task_struct *tsk,
  75        struct mm_struct *mm)
  76{
  77#ifndef CONFIG_SMP
  78        mm->context = NO_CONTEXT;
  79#else /* CONFIG_SMP */
  80        int num_cpus = num_online_cpus();
  81        int i;
  82
  83        for (i = 0 ; i < num_cpus ; i++)
  84                mm->context[i] = NO_CONTEXT;
  85#endif /* CONFIG_SMP */
  86
  87        return 0;
  88}
  89
  90/*
  91 * Destroy context related info for an mm_struct that is about
  92 * to be put to rest.
  93 */
  94#define destroy_context(mm)     do { } while (0)
  95
  96static inline void set_asid(unsigned long asid)
  97{
  98        *(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
  99}
 100
 101static inline unsigned long get_asid(void)
 102{
 103        unsigned long asid;
 104
 105        asid = *(volatile long *)MASID;
 106        asid &= MMU_CONTEXT_ASID_MASK;
 107
 108        return asid;
 109}
 110
 111/*
 112 * After we have set current->mm to a new value, this activates
 113 * the context for the new mm so we see the new mappings.
 114 */
 115static inline void activate_context(struct mm_struct *mm)
 116{
 117        get_mmu_context(mm);
 118        set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
 119}
 120
 121static inline void switch_mm(struct mm_struct *prev,
 122        struct mm_struct *next, struct task_struct *tsk)
 123{
 124#ifdef CONFIG_SMP
 125        int cpu = smp_processor_id();
 126#endif  /* CONFIG_SMP */
 127
 128        if (prev != next) {
 129#ifdef CONFIG_SMP
 130                cpumask_set_cpu(cpu, mm_cpumask(next));
 131#endif /* CONFIG_SMP */
 132                /* Set MPTB = next->pgd */
 133                *(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
 134                activate_context(next);
 135        }
 136#ifdef CONFIG_SMP
 137        else
 138                if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)))
 139                        activate_context(next);
 140#endif /* CONFIG_SMP */
 141}
 142
 143#define deactivate_mm(tsk, mm)  do { } while (0)
 144
 145#define activate_mm(prev, next) \
 146        switch_mm((prev), (next), NULL)
 147
 148#else /* not CONFIG_MMU */
 149#define get_mmu_context(mm)             do { } while (0)
 150#define init_new_context(tsk,mm)        (0)
 151#define destroy_context(mm)             do { } while (0)
 152#define set_asid(asid)                  do { } while (0)
 153#define get_asid()                      (0)
 154#define activate_context(mm)            do { } while (0)
 155#define switch_mm(prev,next,tsk)        do { } while (0)
 156#define deactivate_mm(mm,tsk)           do { } while (0)
 157#define activate_mm(prev,next)          do { } while (0)
 158#define enter_lazy_tlb(mm,tsk)          do { } while (0)
 159#endif /* not CONFIG_MMU */
 160
 161#endif /* not __ASSEMBLY__ */
 162
 163#endif /* __KERNEL__ */
 164#endif /* _ASM_M32R_MMU_CONTEXT_H */
 165