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 #include <linux/config.h>
   7
   8 #include <asm/m32r.h>
   9
  10 #define MMU_CONTEXT_ASID_MASK      (0x000000FF)
  11 #define MMU_CONTEXT_VERSION_MASK   (0xFFFFFF00)
  12 #define MMU_CONTEXT_FIRST_VERSION  (0x00000100)
  13 #define NO_CONTEXT                 (0x00000000)
  14
  15
  16 #ifndef __ASSEMBLY__
  17
  18 #include <linux/config.h>
  19 #include <asm/atomic.h>
  20 #include <asm/pgalloc.h>
  21 #include <asm/mmu.h>
  22 #include <asm/tlbflush.h>
  23
  24 /*
  25  * Cache of MMU context last used.
  26  */
  27 #ifndef CONFIG_SMP
  28 extern unsigned long mmu_context_cache_dat;
  29 #define mmu_context_cache       mmu_context_cache_dat
  30 #define mm_context(mm)          mm->context
  31 #else /* not CONFIG_SMP */
  32 extern unsigned long mmu_context_cache_dat[];
  33 #define mmu_context_cache       mmu_context_cache_dat[smp_processor_id()]
  34 #define mm_context(mm)          mm->context[smp_processor_id()]
  35 #endif /* not CONFIG_SMP */
  36
  37 #define set_tlb_tag(entry, tag)         (*entry = (tag & PAGE_MASK)|get_asid())
  38 #define set_tlb_data(entry, data)       (*entry = (data | _PAGE_PRESENT))
  39
  40 #ifdef CONFIG_MMU
  41 #define enter_lazy_tlb(mm, tsk) do { } while (0)
  42
  43 static inline void get_new_mmu_context(struct mm_struct *mm)
  44 {
  45         unsigned long mc = ++mmu_context_cache;
  46
  47         if (!(mc & MMU_CONTEXT_ASID_MASK)) {
  48                 /* We exhaust ASID of this version.
  49                    Flush all TLB and start new cycle. */
  50                 local_flush_tlb_all();
  51                 /* Fix version if needed.
  52                    Note that we avoid version #0 to distingush NO_CONTEXT. */
  53                 if (!mc)
  54                         mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
  55         }
  56         mm_context(mm) = mc;
  57 }
  58
  59 /*
  60  * Get MMU context if needed.
  61  */
  62 static inline void get_mmu_context(struct mm_struct *mm)
  63 {
  64         if (mm) {
  65                 unsigned long mc = mmu_context_cache;
  66
  67                 /* Check if we have old version of context.
  68                    If it's old, we need to get new context with new version. */
  69                 if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
  70                         get_new_mmu_context(mm);
  71         }
  72 }
  73
  74 /*
  75  * Initialize the context related info for a new mm_struct
  76  * instance.
  77  */
  78 static inline int init_new_context(struct task_struct *tsk,
  79         struct mm_struct *mm)
  80 {
  81 #ifndef CONFIG_SMP
  82         mm->context = NO_CONTEXT;
  83 #else /* CONFIG_SMP */
  84         int num_cpus = num_online_cpus();
  85         int i;
  86
  87         for (i = 0 ; i < num_cpus ; i++)
  88                 mm->context[i] = NO_CONTEXT;
  89 #endif /* CONFIG_SMP */
  90
  91         return 0;
  92 }
  93
  94 /*
  95  * Destroy context related info for an mm_struct that is about
  96  * to be put to rest.
  97  */
  98 #define destroy_context(mm)     do { } while (0)
  99
 100 static inline void set_asid(unsigned long asid)
 101 {
 102         *(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
 103 }
 104
 105 static inline unsigned long get_asid(void)
 106 {
 107         unsigned long asid;
 108
 109         asid = *(volatile long *)MASID;
 110         asid &= MMU_CONTEXT_ASID_MASK;
 111
 112         return asid;
 113 }
 114
 115 /*
 116  * After we have set current->mm to a new value, this activates
 117  * the context for the new mm so we see the new mappings.
 118  */
 119 static inline void activate_context(struct mm_struct *mm)
 120 {
 121         get_mmu_context(mm);
 122         set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
 123 }
 124
 125 static inline void switch_mm(struct mm_struct *prev,
 126         struct mm_struct *next, struct task_struct *tsk)
 127 {
 128 #ifdef CONFIG_SMP
 129         int cpu = smp_processor_id();
 130 #endif  /* CONFIG_SMP */
 131
 132         if (prev != next) {
 133 #ifdef CONFIG_SMP
 134                 cpu_set(cpu, next->cpu_vm_mask);
 135 #endif /* CONFIG_SMP */
 136                 /* Set MPTB = next->pgd */
 137                 *(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
 138                 activate_context(next);
 139         }
 140 #ifdef CONFIG_SMP
 141         else
 142                 if (!cpu_test_and_set(cpu, next->cpu_vm_mask))
 143                         activate_context(next);
 144 #endif /* CONFIG_SMP */
 145 }
 146
 147 #define deactivate_mm(tsk, mm)  do { } while (0)
 148
 149 #define activate_mm(prev, next) \
 150         switch_mm((prev), (next), NULL)
 151
 152 #else
 153 #define get_mmu_context(mm)             do { } while (0)
 154 #define init_new_context(tsk,mm)        (0)
 155 #define destroy_context(mm)             do { } while (0)
 156 #define set_asid(asid)                  do { } while (0)
 157 #define get_asid()                      (0)
 158 #define activate_context(mm)            do { } while (0)
 159 #define switch_mm(prev,next,tsk)        do { } while (0)
 160 #define deactivate_mm(mm,tsk)           do { } while (0)
 161 #define activate_mm(prev,next)          do { } while (0)
 162 #define enter_lazy_tlb(mm,tsk)          do { } while (0)
 163 #endif /* CONFIG_MMU */
 164
 165
 166 #endif /* not __ASSEMBLY__ */
 167
 168 #endif /* __KERNEL__ */
 169
 170 #endif /* _ASM_M32R_MMU_CONTEXT_H */