arch/m32r/include/asm/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 <linux/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
  24 extern 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 */
  28 extern 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
  39 static 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  */
  58 static 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  */
  74 static 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
  96 static inline void set_asid(unsigned long asid)
  97 {
  98         *(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
  99 }
 100
 101 static 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  */
 115 static 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
 121 static 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 */