riscv/mmu.h

   1 #include "decode.h"
   2 #include "trap.h"
   3
   4 class mmu_t
   5 {
   6 public:
   7   mmu_t(char* _mem, size_t _memsz) : mem(_mem), memsz(_memsz), badvaddr(0) {}
   8
   9   #define load_func(type) \
  10     type##_t load_##type(reg_t addr) { \
  11       check_align_and_bounds(addr, sizeof(type##_t), false, false); \
  12       return *(type##_t*)(mem+addr); \
  13     }
  14
  15   #define store_func(type) \
  16     void store_##type(reg_t addr, type##_t val) { \
  17       check_align_and_bounds(addr, sizeof(type##_t), true, false); \
  18       *(type##_t*)(mem+addr) = val; \
  19     }
  20
  21   insn_t load_insn(reg_t addr, bool rvc)
  22   {
  23     check_align_and_bounds(addr, rvc ? 2 : 4, false, true);
  24     uint16_t lo = *(uint16_t*)(mem+addr);
  25     uint16_t hi = *(uint16_t*)(mem+addr+2);
  26
  27     insn_t insn;
  28     insn.bits = lo | ((uint32_t)hi << 16);
  29
  30     return insn;
  31   }
  32
  33   load_func(uint8)
  34   load_func(uint16)
  35   load_func(uint32)
  36   load_func(uint64)
  37
  38   load_func(int8)
  39   load_func(int16)
  40   load_func(int32)
  41   load_func(int64)
  42
  43   store_func(uint8)
  44   store_func(uint16)
  45   store_func(uint32)
  46   store_func(uint64)
  47
  48   reg_t get_badvaddr() { return badvaddr; }
  49
  50 private:
  51   char* mem;
  52   size_t memsz;
  53   reg_t badvaddr;
  54
  55   void check_align(reg_t addr, int size, bool fetch)
  56   {
  57     if(addr & (size-1))
  58     {
  59       badvaddr = addr;
  60       if(fetch)
  61         throw trap_instruction_address_misaligned;
  62       throw trap_data_address_misaligned;
  63     }
  64   }
  65
  66   void check_bounds(reg_t addr, int size, bool store, bool fetch)
  67   {
  68     if(addr >= memsz || addr + size > memsz)
  69     {
  70       badvaddr = addr;
  71       if(fetch)
  72         throw trap_instruction_access_fault;
  73       throw store ? trap_store_access_fault : trap_load_access_fault;
  74     }
  75   }
  76
  77   void check_align_and_bounds(reg_t addr, int size, bool store, bool fetch)
  78   {
  79     check_align(addr, size, fetch);
  80     check_bounds(addr, size, store, fetch);
  81   }
  82 };