include/asm-m32r/mmu_context.h

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