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 "softfloat.h"
  11 #include "platform.h" // softfloat isNaNF32UI, etc.
  12 #include "internals.h" // ditto
  13
  14 processor_t::processor_t(sim_t* _sim, char* _mem, size_t _memsz)
  15   : sim(_sim), mmu(_mem,_memsz)
  16 {
  17   memset(XPR,0,sizeof(XPR));
  18   memset(FPR,0,sizeof(FPR));
  19   pc = 0;
  20   evec = 0;
  21   epc = 0;
  22   badvaddr = 0;
  23   cause = 0;
  24   pcr_k0 = 0;
  25   pcr_k1 = 0;
  26   tohost = 0;
  27   fromhost = 0;
  28   count = 0;
  29   compare = 0;
  30   set_sr(SR_S | SR_SX);  // SX ignored if 64b mode not supported
  31   set_fsr(0);
  32
  33   memset(counters,0,sizeof(counters));
  34
  35   // vector stuff
  36   utidx = -1;
  37   vlmax = 8;
  38   vl = 0;
  39   nxpr_all = 256;
  40   nfpr_all = 256;
  41   nxpr_use = 0;
  42   nfpr_use = 0;
  43   for (int i=0; i<MAX_UTS; i++)
  44     uts[i] = NULL;
  45
  46   // a few assumptions about endianness, including freg_t union
  47   static_assert(BYTE_ORDER == LITTLE_ENDIAN);
  48   static_assert(sizeof(freg_t) == 8);
  49   static_assert(sizeof(reg_t) == 8);
  50
  51   static_assert(sizeof(insn_t) == 4);
  52   static_assert(sizeof(uint128_t) == 16 && sizeof(int128_t) == 16);
  53 }
  54
  55 void processor_t::init(uint32_t _id, char* _mem, size_t _memsz)
  56 {
  57   id = _id;
  58
  59   for (int i=0; i<MAX_UTS; i++)
  60   {
  61     uts[i] = new processor_t(sim, _mem, _memsz);
  62     uts[i]->set_sr(uts[i]->sr | SR_EF);
  63     uts[i]->set_sr(uts[i]->sr | SR_EV);
  64     uts[i]->utidx = i;
  65   }
  66 }
  67
  68 void processor_t::set_sr(uint32_t val)
  69 {
  70   sr = val & ~SR_ZERO;
  71 #ifndef RISCV_ENABLE_64BIT
  72   sr &= ~(SR_SX | SR_UX);
  73 #endif
  74 #ifndef RISCV_ENABLE_FPU
  75   sr &= ~SR_EF;
  76 #endif
  77 #ifndef RISCV_ENABLE_RVC
  78   sr &= ~SR_EC;
  79 #endif
  80
  81   xprlen = ((sr & SR_S) ? (sr & SR_SX) : (sr & SR_UX)) ? 64 : 32;
  82 }
  83
  84 void processor_t::set_fsr(uint32_t val)
  85 {
  86   fsr = val & ~FSR_ZERO;
  87 }
  88
  89 void processor_t::vcfg()
  90 {
  91   if (nxpr_use == 0 && nfpr_use == 0)
  92     vlmax = 8;
  93   else if (nfpr_use == 0)
  94     vlmax = (nxpr_all-1) / (nxpr_use-1);
  95   else if (nxpr_use == 0)
  96     vlmax = (nfpr_all-1) / (nfpr_use-1);
  97   else
  98     vlmax = std::min((nxpr_all-1) / (nxpr_use-1), (nfpr_all-1) / (nfpr_use-1));
  99
 100   vlmax = std::min(vlmax, MAX_UTS);
 101 }
 102
 103 void processor_t::setvl(int vlapp)
 104 {
 105   vl = std::min(vlmax, vlapp);
 106 }
 107
 108 void processor_t::step(size_t n, bool noisy)
 109 {
 110   size_t i = 0;
 111   while(1) try
 112   {
 113     for( ; i < n; i++)
 114     {
 115       uint32_t interrupts = (cause & CAUSE_IP) >> CAUSE_IP_SHIFT;
 116       interrupts &= (sr & SR_IM) >> SR_IM_SHIFT;
 117       if(interrupts && (sr & SR_ET))
 118         take_trap(trap_interrupt,noisy);
 119
 120       insn_t insn = mmu.load_insn(pc, sr & SR_EC);
 121
 122       reg_t npc = pc + insn_length(insn);
 123
 124       if(noisy)
 125         disasm(insn,pc);
 126
 127       #include "execute.h"
 128
 129       pc = npc;
 130       XPR[0] = 0;
 131
 132       if(count++ == compare)
 133         cause |= 1 << (TIMER_IRQ+CAUSE_IP_SHIFT);
 134     }
 135     return;
 136   }
 137   catch(trap_t t)
 138   {
 139     i++;
 140     take_trap(t,noisy);
 141   }
 142   catch(vt_command_t cmd)
 143   {
 144     if (cmd == vt_command_stop)
 145       return;
 146   }
 147 }
 148
 149 void processor_t::take_trap(trap_t t, bool noisy)
 150 {
 151   demand(t < NUM_TRAPS, "internal error: bad trap number %d", int(t));
 152   demand(sr & SR_ET, "error mode on core %d!\ntrap %s, pc 0x%016llx",
 153          id, trap_name(t), (unsigned long long)pc);
 154   if(noisy)
 155     printf("core %3d: trap %s, pc 0x%016llx\n",
 156            id, trap_name(t), (unsigned long long)pc);
 157
 158   set_sr((((sr & ~SR_ET) | SR_S) & ~SR_PS) | ((sr & SR_S) ? SR_PS : 0));
 159   cause = (cause & ~CAUSE_EXCCODE) | (t << CAUSE_EXCCODE_SHIFT);
 160   epc = pc;
 161   pc = evec;
 162   badvaddr = mmu.get_badvaddr();
 163 }
 164
 165 void processor_t::disasm(insn_t insn, reg_t pc)
 166 {
 167   printf("core %3d: 0x%016llx (0x%08x) ",id,(unsigned long long)pc,insn.bits);
 168
 169   #ifdef RISCV_HAVE_LIBOPCODES
 170   disassemble_info info;
 171   INIT_DISASSEMBLE_INFO(info, stdout, fprintf);
 172   info.flavour = bfd_target_unknown_flavour;
 173   info.arch = bfd_arch_mips;
 174   info.mach = 101; // XXX bfd_mach_mips_riscv requires modified bfd.h
 175   info.endian = BFD_ENDIAN_LITTLE;
 176   info.buffer = (bfd_byte*)&insn;
 177   info.buffer_length = sizeof(insn);
 178   info.buffer_vma = pc;
 179
 180   demand(print_insn_little_mips(pc, &info) == sizeof(insn), "disasm bug!");
 181   #else
 182   printf("unknown");
 183   #endif
 184   printf("\n");
 185 }