riscv/clint.cc

   1 #include "devices.h"
   2 #include "processor.h"
   3
   4 clint_t::clint_t(std::vector<processor_t*>& procs)
   5   : procs(procs), mtimecmp(procs.size())
   6 {
   7 }
   8
   9 /* 0000 msip hart 0
  10  * 0004 msip hart 1
  11  * 4000 mtimecmp hart 0 lo
  12  * 4004 mtimecmp hart 0 hi
  13  * 4008 mtimecmp hart 1 lo
  14  * 400c mtimecmp hart 1 hi
  15  * bff8 mtime lo
  16  * bffc mtime hi
  17  */
  18
  19 #define MSIP_BASE       0x0
  20 #define MTIMECMP_BASE   0x4000
  21 #define MTIME_BASE      0xbff8
  22
  23 bool clint_t::load(reg_t addr, size_t len, uint8_t* bytes)
  24 {
  25   if (addr >= MSIP_BASE && addr + len <= MSIP_BASE + procs.size()*sizeof(msip_t)) {
  26     std::vector<msip_t> msip(procs.size());
  27     for (size_t i = 0; i < procs.size(); ++i)
  28       msip[i] = !!(procs[i]->state.mip & MIP_MSIP);
  29     memcpy(bytes, (uint8_t*)&msip[0] + addr - MSIP_BASE, len);
  30   } else if (addr >= MTIMECMP_BASE && addr + len <= MTIMECMP_BASE + procs.size()*sizeof(mtimecmp_t)) {
  31     memcpy(bytes, (uint8_t*)&mtimecmp[0] + addr - MTIMECMP_BASE, len);
  32   } else if (addr >= MTIME_BASE && addr + len <= MTIME_BASE + sizeof(mtime_t)) {
  33     memcpy(bytes, (uint8_t*)&mtime + addr - MTIME_BASE, len);
  34   } else {
  35     return false;
  36   }
  37   return true;
  38 }
  39
  40 bool clint_t::store(reg_t addr, size_t len, const uint8_t* bytes)
  41 {
  42   if (addr >= MSIP_BASE && addr + len <= MSIP_BASE + procs.size()*sizeof(msip_t)) {
  43     std::vector<msip_t> msip(procs.size());
  44     std::vector<msip_t> mask(procs.size(), 0);
  45     memcpy((uint8_t*)&msip[0] + addr - MSIP_BASE, bytes, len);
  46     memset((uint8_t*)&mask[0] + addr - MSIP_BASE, 0xff, len);
  47     for (size_t i = 0; i < procs.size(); ++i) {
  48       if (!(mask[i] & 0xFF)) continue;
  49       procs[i]->state.mip &= ~MIP_MSIP;
  50       if (!!(msip[i] & 1))
  51         procs[i]->state.mip |= MIP_MSIP;
  52     }
  53   } else if (addr >= MTIMECMP_BASE && addr + len <= MTIMECMP_BASE + procs.size()*sizeof(mtimecmp_t)) {
  54     memcpy((uint8_t*)&mtimecmp[0] + addr - MTIMECMP_BASE, bytes, len);
  55   } else if (addr >= MTIME_BASE && addr + len <= MTIME_BASE + sizeof(mtime_t)) {
  56     memcpy((uint8_t*)&mtime + addr - MTIME_BASE, bytes, len);
  57   } else {
  58     return false;
  59   }
  60   increment(0);
  61   return true;
  62 }
  63
  64 void clint_t::increment(reg_t inc)
  65 {
  66   mtime += inc;
  67   for (size_t i = 0; i < procs.size(); i++) {
  68     procs[i]->state.mip &= ~MIP_MTIP;
  69     if (mtime >= mtimecmp[i])
  70       procs[i]->state.mip |= MIP_MTIP;
  71   }
  72 }