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;
  29     if((lo & 0x3) == 0x3)
  30       insn.bits |= (uint32_t)hi << 16;
  31
  32     return insn;
  33   }
  34
  35   load_func(uint8)
  36   load_func(uint16)
  37   load_func(uint32)
  38   load_func(uint64)
  39
  40   load_func(int8)
  41   load_func(int16)
  42   load_func(int32)
  43   load_func(int64)
  44
  45   store_func(uint8)
  46   store_func(uint16)
  47   store_func(uint32)
  48   store_func(uint64)
  49
  50   reg_t get_badvaddr() { return badvaddr; }
  51
  52 private:
  53   char* mem;
  54   size_t memsz;
  55   reg_t badvaddr;
  56
  57   void check_align(reg_t addr, int size, bool fetch)
  58   {
  59     if(addr & (size-1))
  60     {
  61       badvaddr = addr;
  62       if(fetch)
  63         throw trap_instruction_address_misaligned;
  64       throw trap_data_address_misaligned;
  65     }
  66   }
  67
  68   void check_bounds(reg_t addr, int size, bool store, bool fetch)
  69   {
  70     if(addr >= memsz || addr + size > memsz)
  71     {
  72       badvaddr = addr;
  73       if(fetch)
  74         throw trap_instruction_access_fault;
  75       throw store ? trap_store_access_fault : trap_load_access_fault;
  76     }
  77   }
  78
  79   void check_align_and_bounds(reg_t addr, int size, bool store, bool fetch)
  80   {
  81     check_align(addr, size, fetch);
  82     check_bounds(addr, size, store, fetch);
  83   }
  84 };