include/asm-m32r/mmu_context.h

   1 #ifndef _ASM_M32R_MMU_CONTEXT_H
   2 #define _ASM_M32R_MMU_CONTEXT_H
   3
   4 #ifdef __KERNEL__
   5
   6
   7 #include <asm/m32r.h>
   8
   9 #define MMU_CONTEXT_ASID_MASK      (0x000000FF)
  10 #define MMU_CONTEXT_VERSION_MASK   (0xFFFFFF00)
  11 #define MMU_CONTEXT_FIRST_VERSION  (0x00000100)
  12 #define NO_CONTEXT                 (0x00000000)
  13
  14
  15 #ifndef __ASSEMBLY__
  16
  17 #include <asm/atomic.h>
  18 #include <asm/pgalloc.h>
  19 #include <asm/mmu.h>
  20 #include <asm/tlbflush.h>
  21
  22 /*
  23  * Cache of MMU context last used.
  24  */
  25 #ifndef CONFIG_SMP
  26 extern unsigned long mmu_context_cache_dat;
  27 #define mmu_context_cache       mmu_context_cache_dat
  28 #define mm_context(mm)          mm->context
  29 #else /* not CONFIG_SMP */
  30 extern unsigned long mmu_context_cache_dat[];
  31 #define mmu_context_cache       mmu_context_cache_dat[smp_processor_id()]
  32 #define mm_context(mm)          mm->context[smp_processor_id()]
  33 #endif /* not CONFIG_SMP */
  34
  35 #define set_tlb_tag(entry, tag)         (*entry = (tag & PAGE_MASK)|get_asid())
  36 #define set_tlb_data(entry, data)       (*entry = (data | _PAGE_PRESENT))
  37
  38 #ifdef CONFIG_MMU
  39 #define enter_lazy_tlb(mm, tsk) do { } while (0)
  40
  41 static inline void get_new_mmu_context(struct mm_struct *mm)
  42 {
  43         unsigned long mc = ++mmu_context_cache;
  44
  45         if (!(mc & MMU_CONTEXT_ASID_MASK)) {
  46                 /* We exhaust ASID of this version.
  47                    Flush all TLB and start new cycle. */
  48                 local_flush_tlb_all();
  49                 /* Fix version if needed.
  50                    Note that we avoid version #0 to distingush NO_CONTEXT. */
  51                 if (!mc)
  52                         mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
  53         }
  54         mm_context(mm) = mc;
  55 }
  56
  57 /*
  58  * Get MMU context if needed.
  59  */
  60 static inline void get_mmu_context(struct mm_struct *mm)
  61 {
  62         if (mm) {
  63                 unsigned long mc = mmu_context_cache;
  64
  65                 /* Check if we have old version of context.
  66                    If it's old, we need to get new context with new version. */
  67                 if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
  68                         get_new_mmu_context(mm);
  69         }
  70 }
  71
  72 /*
  73  * Initialize the context related info for a new mm_struct
  74  * instance.
  75  */
  76 static inline int init_new_context(struct task_struct *tsk,
  77         struct mm_struct *mm)
  78 {
  79 #ifndef CONFIG_SMP
  80         mm->context = NO_CONTEXT;
  81 #else /* CONFIG_SMP */
  82         int num_cpus = num_online_cpus();
  83         int i;
  84
  85         for (i = 0 ; i < num_cpus ; i++)
  86                 mm->context[i] = NO_CONTEXT;
  87 #endif /* CONFIG_SMP */
  88
  89         return 0;
  90 }
  91
  92 /*
  93  * Destroy context related info for an mm_struct that is about
  94  * to be put to rest.
  95  */
  96 #define destroy_context(mm)     do { } while (0)
  97
  98 static inline void set_asid(unsigned long asid)
  99 {
 100         *(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
 101 }
 102
 103 static inline unsigned long get_asid(void)
 104 {
 105         unsigned long asid;
 106
 107         asid = *(volatile long *)MASID;
 108         asid &= MMU_CONTEXT_ASID_MASK;
 109
 110         return asid;
 111 }
 112
 113 /*
 114  * After we have set current->mm to a new value, this activates
 115  * the context for the new mm so we see the new mappings.
 116  */
 117 static inline void activate_context(struct mm_struct *mm)
 118 {
 119         get_mmu_context(mm);
 120         set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
 121 }
 122
 123 static inline void switch_mm(struct mm_struct *prev,
 124         struct mm_struct *next, struct task_struct *tsk)
 125 {
 126 #ifdef CONFIG_SMP
 127         int cpu = smp_processor_id();
 128 #endif  /* CONFIG_SMP */
 129
 130         if (prev != next) {
 131 #ifdef CONFIG_SMP
 132                 cpu_set(cpu, next->cpu_vm_mask);
 133 #endif /* CONFIG_SMP */
 134                 /* Set MPTB = next->pgd */
 135                 *(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
 136                 activate_context(next);
 137         }
 138 #ifdef CONFIG_SMP
 139         else
 140                 if (!cpu_test_and_set(cpu, next->cpu_vm_mask))
 141                         activate_context(next);
 142 #endif /* CONFIG_SMP */
 143 }
 144
 145 #define deactivate_mm(tsk, mm)  do { } while (0)
 146
 147 #define activate_mm(prev, next) \
 148         switch_mm((prev), (next), NULL)
 149
 150 #else
 151 #define get_mmu_context(mm)             do { } while (0)
 152 #define init_new_context(tsk,mm)        (0)
 153 #define destroy_context(mm)             do { } while (0)
 154 #define set_asid(asid)                  do { } while (0)
 155 #define get_asid()                      (0)
 156 #define activate_context(mm)            do { } while (0)
 157 #define switch_mm(prev,next,tsk)        do { } while (0)
 158 #define deactivate_mm(mm,tsk)           do { } while (0)
 159 #define activate_mm(prev,next)          do { } while (0)
 160 #define enter_lazy_tlb(mm,tsk)          do { } while (0)
 161 #endif /* CONFIG_MMU */
 162
 163
 164 #endif /* not __ASSEMBLY__ */
 165
 166 #endif /* __KERNEL__ */
 167
 168 #endif /* _ASM_M32R_MMU_CONTEXT_H */