riscv/processor.cc

   1 #include "processor.h"
   2 #include <bfd.h>
   3 #include <dis-asm.h>
   4 #include <cmath>
   5 #include <cstdlib>
   6 #include <iostream>
   7 #include "common.h"
   8 #include "config.h"
   9 #include "sim.h"
  10 #include "icsim.h"
  11
  12 processor_t::processor_t(sim_t* _sim, mmu_t* _mmu)
  13   : sim(_sim), mmu(*_mmu)
  14 {
  15   // a few assumptions about endianness, including freg_t union
  16   static_assert(BYTE_ORDER == LITTLE_ENDIAN);
  17   static_assert(sizeof(freg_t) == 8);
  18   static_assert(sizeof(reg_t) == 8);
  19
  20   static_assert(sizeof(insn_t) == 4);
  21   static_assert(sizeof(uint128_t) == 16 && sizeof(int128_t) == 16);
  22
  23   icsim = NULL;
  24   dcsim = NULL;
  25   itlbsim = NULL;
  26   dtlbsim = NULL;
  27
  28   reset();
  29 }
  30
  31 processor_t::~processor_t()
  32 {
  33   if(icsim)
  34     icsim->print_stats();
  35   delete icsim;
  36
  37   if(itlbsim)
  38     itlbsim->print_stats();
  39   delete itlbsim;
  40
  41   if(dcsim)
  42     dcsim->print_stats();
  43   delete dcsim;
  44
  45   if(dtlbsim)
  46     dtlbsim->print_stats();
  47   delete dtlbsim;
  48 }
  49
  50 void processor_t::init(uint32_t _id, icsim_t* default_icache,
  51                        icsim_t* default_dcache)
  52 {
  53   id = _id;
  54
  55   for (int i=0; i<MAX_UTS; i++)
  56   {
  57     uts[i] = new processor_t(sim, &mmu);
  58     uts[i]->id = id;
  59     uts[i]->set_sr(uts[i]->sr | SR_EF);
  60     uts[i]->set_sr(uts[i]->sr | SR_EV);
  61     uts[i]->utidx = i;
  62   }
  63
  64   #ifdef RISCV_ENABLE_ICSIM
  65   icsim = new icsim_t(*default_icache);
  66   mmu.set_icsim(icsim);
  67   itlbsim = new icsim_t(1, 8, 4096, "ITLB");
  68   mmu.set_itlbsim(itlbsim);
  69   #endif
  70   #ifdef RISCV_ENABLE_ICSIM
  71   dcsim = new icsim_t(*default_dcache);
  72   mmu.set_dcsim(dcsim);
  73   dtlbsim = new icsim_t(1, 8, 4096, "DTLB");
  74   mmu.set_dtlbsim(dtlbsim);
  75   #endif
  76 }
  77
  78 void processor_t::reset()
  79 {
  80   run = false;
  81
  82   memset(XPR,0,sizeof(XPR));
  83   memset(FPR,0,sizeof(FPR));
  84
  85   pc = 0;
  86   evec = 0;
  87   epc = 0;
  88   badvaddr = 0;
  89   cause = 0;
  90   pcr_k0 = 0;
  91   pcr_k1 = 0;
  92   tohost = 0;
  93   fromhost = 0;
  94   count = 0;
  95   compare = 0;
  96   cycle = 0;
  97   set_sr(SR_S | SR_SX);  // SX ignored if 64b mode not supported
  98   set_fsr(0);
  99
 100   // vector stuff
 101   vecbanks = 0xff;
 102   vecbanks_count = 8;
 103   utidx = -1;
 104   vlmax = 32;
 105   vl = 0;
 106   nxfpr_bank = 256;
 107   nxpr_use = 32;
 108   nfpr_use = 32;
 109   for (int i=0; i<MAX_UTS; i++)
 110     uts[i] = NULL;
 111 }
 112
 113 void processor_t::set_sr(uint32_t val)
 114 {
 115   sr = val & ~SR_ZERO;
 116 #ifndef RISCV_ENABLE_64BIT
 117   sr &= ~(SR_SX | SR_UX);
 118 #endif
 119 #ifndef RISCV_ENABLE_FPU
 120   sr &= ~SR_EF;
 121 #endif
 122 #ifndef RISCV_ENABLE_RVC
 123   sr &= ~SR_EC;
 124 #endif
 125 #ifndef RISCV_ENABLE_VEC
 126   sr &= ~SR_EV;
 127 #endif
 128
 129   mmu.set_vm_enabled(sr & SR_VM);
 130   mmu.set_supervisor(sr & SR_S);
 131   mmu.flush_tlb();
 132
 133   xprlen = ((sr & SR_S) ? (sr & SR_SX) : (sr & SR_UX)) ? 64 : 32;
 134 }
 135
 136 void processor_t::set_fsr(uint32_t val)
 137 {
 138   fsr = val & ~FSR_ZERO;
 139 }
 140
 141 void processor_t::vcfg()
 142 {
 143   if (nxpr_use + nfpr_use < 2)
 144     vlmax = nxfpr_bank * vecbanks_count;
 145   else
 146     vlmax = (nxfpr_bank / (nxpr_use + nfpr_use - 1)) * vecbanks_count;
 147
 148   vlmax = std::min(vlmax, MAX_UTS);
 149 }
 150
 151 void processor_t::setvl(int vlapp)
 152 {
 153   vl = std::min(vlmax, vlapp);
 154 }
 155
 156 void processor_t::take_interrupt()
 157 {
 158   uint32_t interrupts = (cause & CAUSE_IP) >> CAUSE_IP_SHIFT;
 159   interrupts &= (sr & SR_IM) >> SR_IM_SHIFT;
 160
 161   if(interrupts && (sr & SR_ET))
 162     throw trap_interrupt;
 163 }
 164
 165 void processor_t::step(size_t n, bool noisy)
 166 {
 167   if(!run)
 168     return;
 169
 170   size_t i = 0;
 171   while(1) try
 172   {
 173     take_interrupt();
 174
 175     #define execute_insn(noisy) \
 176       do { insn_t insn = mmu.load_insn(pc, sr & SR_EC); \
 177       if(noisy) disasm(insn,pc); \
 178       pc = dispatch_table[insn.bits % DISPATCH_TABLE_SIZE](this, insn, pc); \
 179       XPR[0] = 0; } while(0)
 180
 181     if(noisy) for( ; i < n; i++)
 182       execute_insn(true);
 183     else
 184     {
 185       for( ; n > 3 && i < n-3; i+=4)
 186       {
 187         execute_insn(false);
 188         execute_insn(false);
 189         execute_insn(false);
 190         execute_insn(false);
 191       }
 192       for( ; i < n; i++)
 193         execute_insn(false);
 194     }
 195
 196     break;
 197   }
 198   catch(trap_t t)
 199   {
 200     i++;
 201     take_trap(t,noisy);
 202   }
 203   catch(vt_command_t cmd)
 204   {
 205     i++;
 206     if (cmd == vt_command_stop)
 207       break;
 208   }
 209   catch(halt_t t)
 210   {
 211     reset();
 212     return;
 213   }
 214
 215   cycle += i;
 216
 217   typeof(count) old_count = count;
 218   typeof(count) max_count = -1;
 219   count += i;
 220   if(old_count < compare && (count >= compare || old_count > max_count-i))
 221     cause |= 1 << (TIMER_IRQ+CAUSE_IP_SHIFT);
 222 }
 223
 224 void processor_t::take_trap(trap_t t, bool noisy)
 225 {
 226   demand(t < NUM_TRAPS, "internal error: bad trap number %d", int(t));
 227   demand(sr & SR_ET, "error mode on core %d!\ntrap %s, pc 0x%016llx",
 228          id, trap_name(t), (unsigned long long)pc);
 229   if(noisy)
 230     printf("core %3d: trap %s, pc 0x%016llx\n",
 231            id, trap_name(t), (unsigned long long)pc);
 232
 233   set_sr((((sr & ~SR_ET) | SR_S) & ~SR_PS) | ((sr & SR_S) ? SR_PS : 0));
 234   cause = (cause & ~CAUSE_EXCCODE) | (t << CAUSE_EXCCODE_SHIFT);
 235   epc = pc;
 236   pc = evec;
 237   badvaddr = mmu.get_badvaddr();
 238 }
 239
 240 void processor_t::deliver_ipi()
 241 {
 242   cause |= 1 << (IPI_IRQ+CAUSE_IP_SHIFT);
 243   run = true;
 244 }
 245
 246 void processor_t::disasm(insn_t insn, reg_t pc)
 247 {
 248   printf("core %3d: 0x%016llx (0x%08x) ",id,(unsigned long long)pc,insn.bits);
 249
 250   #ifdef RISCV_HAVE_LIBOPCODES
 251   disassemble_info info;
 252   INIT_DISASSEMBLE_INFO(info, stdout, fprintf);
 253   info.flavour = bfd_target_unknown_flavour;
 254   info.arch = bfd_arch_mips;
 255   info.mach = 101; // XXX bfd_mach_mips_riscv requires modified bfd.h
 256   info.endian = BFD_ENDIAN_LITTLE;
 257   info.buffer = (bfd_byte*)&insn;
 258   info.buffer_length = sizeof(insn);
 259   info.buffer_vma = pc;
 260
 261   int ret = print_insn_little_mips(pc, &info);
 262   demand(ret == insn_length(insn.bits), "disasm bug!");
 263   #else
 264   printf("unknown");
 265   #endif
 266   printf("\n");
 267 }