arch/m32r/include/asm/mmu_context.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_M32R_MMU_CONTEXT_H
   3 #define _ASM_M32R_MMU_CONTEXT_H
   4 #ifdef __KERNEL__
   5
   6 #include <asm/m32r.h>
   7
   8 #define MMU_CONTEXT_ASID_MASK      (0x000000FF)
   9 #define MMU_CONTEXT_VERSION_MASK   (0xFFFFFF00)
  10 #define MMU_CONTEXT_FIRST_VERSION  (0x00000100)
  11 #define NO_CONTEXT                 (0x00000000)
  12
  13 #ifndef __ASSEMBLY__
  14
  15 #include <linux/atomic.h>
  16 #include <linux/mm_types.h>
  17
  18 #include <asm/pgalloc.h>
  19 #include <asm/mmu.h>
  20 #include <asm/tlbflush.h>
  21 #include <asm-generic/mm_hooks.h>
  22
  23 /*
  24  * Cache of MMU context last used.
  25  */
  26 #ifndef CONFIG_SMP
  27 extern unsigned long mmu_context_cache_dat;
  28 #define mmu_context_cache       mmu_context_cache_dat
  29 #define mm_context(mm)          mm->context
  30 #else /* not CONFIG_SMP */
  31 extern unsigned long mmu_context_cache_dat[];
  32 #define mmu_context_cache       mmu_context_cache_dat[smp_processor_id()]
  33 #define mm_context(mm)          mm->context[smp_processor_id()]
  34 #endif /* not CONFIG_SMP */
  35
  36 #define set_tlb_tag(entry, tag)         (*entry = (tag & PAGE_MASK)|get_asid())
  37 #define set_tlb_data(entry, data)       (*entry = (data | _PAGE_PRESENT))
  38
  39 #ifdef CONFIG_MMU
  40 #define enter_lazy_tlb(mm, tsk) do { } while (0)
  41
  42 static inline void get_new_mmu_context(struct mm_struct *mm)
  43 {
  44         unsigned long mc = ++mmu_context_cache;
  45
  46         if (!(mc & MMU_CONTEXT_ASID_MASK)) {
  47                 /* We exhaust ASID of this version.
  48                    Flush all TLB and start new cycle. */
  49                 local_flush_tlb_all();
  50                 /* Fix version if needed.
  51                    Note that we avoid version #0 to distinguish NO_CONTEXT. */
  52                 if (!mc)
  53                         mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
  54         }
  55         mm_context(mm) = mc;
  56 }
  57
  58 /*
  59  * Get MMU context if needed.
  60  */
  61 static inline void get_mmu_context(struct mm_struct *mm)
  62 {
  63         if (mm) {
  64                 unsigned long mc = mmu_context_cache;
  65
  66                 /* Check if we have old version of context.
  67                    If it's old, we need to get new context with new version. */
  68                 if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
  69                         get_new_mmu_context(mm);
  70         }
  71 }
  72
  73 /*
  74  * Initialize the context related info for a new mm_struct
  75  * instance.
  76  */
  77 static inline int init_new_context(struct task_struct *tsk,
  78         struct mm_struct *mm)
  79 {
  80 #ifndef CONFIG_SMP
  81         mm->context = NO_CONTEXT;
  82 #else /* CONFIG_SMP */
  83         int num_cpus = num_online_cpus();
  84         int i;
  85
  86         for (i = 0 ; i < num_cpus ; i++)
  87                 mm->context[i] = NO_CONTEXT;
  88 #endif /* CONFIG_SMP */
  89
  90         return 0;
  91 }
  92
  93 /*
  94  * Destroy context related info for an mm_struct that is about
  95  * to be put to rest.
  96  */
  97 #define destroy_context(mm)     do { } while (0)
  98
  99 static inline void set_asid(unsigned long asid)
 100 {
 101         *(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
 102 }
 103
 104 static inline unsigned long get_asid(void)
 105 {
 106         unsigned long asid;
 107
 108         asid = *(volatile long *)MASID;
 109         asid &= MMU_CONTEXT_ASID_MASK;
 110
 111         return asid;
 112 }
 113
 114 /*
 115  * After we have set current->mm to a new value, this activates
 116  * the context for the new mm so we see the new mappings.
 117  */
 118 static inline void activate_context(struct mm_struct *mm)
 119 {
 120         get_mmu_context(mm);
 121         set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
 122 }
 123
 124 static inline void switch_mm(struct mm_struct *prev,
 125         struct mm_struct *next, struct task_struct *tsk)
 126 {
 127 #ifdef CONFIG_SMP
 128         int cpu = smp_processor_id();
 129 #endif  /* CONFIG_SMP */
 130
 131         if (prev != next) {
 132 #ifdef CONFIG_SMP
 133                 cpumask_set_cpu(cpu, mm_cpumask(next));
 134 #endif /* CONFIG_SMP */
 135                 /* Set MPTB = next->pgd */
 136                 *(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
 137                 activate_context(next);
 138         }
 139 #ifdef CONFIG_SMP
 140         else
 141                 if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)))
 142                         activate_context(next);
 143 #endif /* CONFIG_SMP */
 144 }
 145
 146 #define deactivate_mm(tsk, mm)  do { } while (0)
 147
 148 #define activate_mm(prev, next) \
 149         switch_mm((prev), (next), NULL)
 150
 151 #else /* not CONFIG_MMU */
 152 #define get_mmu_context(mm)             do { } while (0)
 153 #define init_new_context(tsk,mm)        (0)
 154 #define destroy_context(mm)             do { } while (0)
 155 #define set_asid(asid)                  do { } while (0)
 156 #define get_asid()                      (0)
 157 #define activate_context(mm)            do { } while (0)
 158 #define switch_mm(prev,next,tsk)        do { } while (0)
 159 #define deactivate_mm(mm,tsk)           do { } while (0)
 160 #define activate_mm(prev,next)          do { } while (0)
 161 #define enter_lazy_tlb(mm,tsk)          do { } while (0)
 162 #endif /* not CONFIG_MMU */
 163
 164 #endif /* not __ASSEMBLY__ */
 165
 166 #endif /* __KERNEL__ */
 167 #endif /* _ASM_M32R_MMU_CONTEXT_H */