target/nios2/cpu.c

   1 /*
   2  * QEMU Nios II CPU
   3  *
   4  * Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see
  18  * <http://www.gnu.org/licenses/lgpl-2.1.html>
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "qemu/module.h"
  23 #include "qapi/error.h"
  24 #include "cpu.h"
  25 #include "exec/log.h"
  26 #include "exec/gdbstub.h"
  27 #include "hw/qdev-properties.h"
  28
  29 static void nios2_cpu_set_pc(CPUState *cs, vaddr value)
  30 {
  31     Nios2CPU *cpu = NIOS2_CPU(cs);
  32     CPUNios2State *env = &cpu->env;
  33
  34     env->regs[R_PC] = value;
  35 }
  36
  37 static bool nios2_cpu_has_work(CPUState *cs)
  38 {
  39     return cs->interrupt_request & (CPU_INTERRUPT_HARD | CPU_INTERRUPT_NMI);
  40 }
  41
  42 static void nios2_cpu_reset(DeviceState *dev)
  43 {
  44     CPUState *cs = CPU(dev);
  45     Nios2CPU *cpu = NIOS2_CPU(cs);
  46     Nios2CPUClass *ncc = NIOS2_CPU_GET_CLASS(cpu);
  47     CPUNios2State *env = &cpu->env;
  48
  49     if (qemu_loglevel_mask(CPU_LOG_RESET)) {
  50         qemu_log("CPU Reset (CPU %d)\n", cs->cpu_index);
  51         log_cpu_state(cs, 0);
  52     }
  53
  54     ncc->parent_reset(dev);
  55
  56     memset(env->regs, 0, sizeof(uint32_t) * NUM_CORE_REGS);
  57     env->regs[R_PC] = cpu->reset_addr;
  58
  59 #if defined(CONFIG_USER_ONLY)
  60     /* Start in user mode with interrupts enabled. */
  61     env->regs[CR_STATUS] = CR_STATUS_U | CR_STATUS_PIE;
  62 #else
  63     env->regs[CR_STATUS] = 0;
  64 #endif
  65 }
  66
  67 #ifndef CONFIG_USER_ONLY
  68 static void nios2_cpu_set_irq(void *opaque, int irq, int level)
  69 {
  70     Nios2CPU *cpu = opaque;
  71     CPUNios2State *env = &cpu->env;
  72     CPUState *cs = CPU(cpu);
  73
  74     env->regs[CR_IPENDING] = deposit32(env->regs[CR_IPENDING], irq, 1, !!level);
  75
  76     env->irq_pending = env->regs[CR_IPENDING] & env->regs[CR_IENABLE];
  77
  78     if (env->irq_pending && (env->regs[CR_STATUS] & CR_STATUS_PIE)) {
  79         env->irq_pending = 0;
  80         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
  81     } else if (!env->irq_pending) {
  82         cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
  83     }
  84 }
  85 #endif
  86
  87 static void nios2_cpu_initfn(Object *obj)
  88 {
  89     Nios2CPU *cpu = NIOS2_CPU(obj);
  90
  91     cpu_set_cpustate_pointers(cpu);
  92
  93 #if !defined(CONFIG_USER_ONLY)
  94     mmu_init(&cpu->env);
  95
  96     /*
  97      * These interrupt lines model the IIC (internal interrupt
  98      * controller). QEMU does not currently support the EIC
  99      * (external interrupt controller) -- if we did it would be
 100      * a separate device in hw/intc with a custom interface to
 101      * the CPU, and boards using it would not wire up these IRQ lines.
 102      */
 103     qdev_init_gpio_in_named(DEVICE(cpu), nios2_cpu_set_irq, "IRQ", 32);
 104 #endif
 105 }
 106
 107 static ObjectClass *nios2_cpu_class_by_name(const char *cpu_model)
 108 {
 109     return object_class_by_name(TYPE_NIOS2_CPU);
 110 }
 111
 112 static void nios2_cpu_realizefn(DeviceState *dev, Error **errp)
 113 {
 114     CPUState *cs = CPU(dev);
 115     Nios2CPUClass *ncc = NIOS2_CPU_GET_CLASS(dev);
 116     Error *local_err = NULL;
 117
 118     cpu_exec_realizefn(cs, &local_err);
 119     if (local_err != NULL) {
 120         error_propagate(errp, local_err);
 121         return;
 122     }
 123
 124     qemu_init_vcpu(cs);
 125     cpu_reset(cs);
 126
 127     ncc->parent_realize(dev, errp);
 128 }
 129
 130 static bool nios2_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
 131 {
 132     Nios2CPU *cpu = NIOS2_CPU(cs);
 133     CPUNios2State *env = &cpu->env;
 134
 135     if ((interrupt_request & CPU_INTERRUPT_HARD) &&
 136         (env->regs[CR_STATUS] & CR_STATUS_PIE)) {
 137         cs->exception_index = EXCP_IRQ;
 138         nios2_cpu_do_interrupt(cs);
 139         return true;
 140     }
 141     return false;
 142 }
 143
 144
 145 static void nios2_cpu_disas_set_info(CPUState *cpu, disassemble_info *info)
 146 {
 147     /* NOTE: NiosII R2 is not supported yet. */
 148     info->mach = bfd_arch_nios2;
 149 #ifdef TARGET_WORDS_BIGENDIAN
 150     info->print_insn = print_insn_big_nios2;
 151 #else
 152     info->print_insn = print_insn_little_nios2;
 153 #endif
 154 }
 155
 156 static int nios2_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
 157 {
 158     Nios2CPU *cpu = NIOS2_CPU(cs);
 159     CPUClass *cc = CPU_GET_CLASS(cs);
 160     CPUNios2State *env = &cpu->env;
 161
 162     if (n > cc->gdb_num_core_regs) {
 163         return 0;
 164     }
 165
 166     if (n < 32) {          /* GP regs */
 167         return gdb_get_reg32(mem_buf, env->regs[n]);
 168     } else if (n == 32) {    /* PC */
 169         return gdb_get_reg32(mem_buf, env->regs[R_PC]);
 170     } else if (n < 49) {     /* Status regs */
 171         return gdb_get_reg32(mem_buf, env->regs[n - 1]);
 172     }
 173
 174     /* Invalid regs */
 175     return 0;
 176 }
 177
 178 static int nios2_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 179 {
 180     Nios2CPU *cpu = NIOS2_CPU(cs);
 181     CPUClass *cc = CPU_GET_CLASS(cs);
 182     CPUNios2State *env = &cpu->env;
 183
 184     if (n > cc->gdb_num_core_regs) {
 185         return 0;
 186     }
 187
 188     if (n < 32) {            /* GP regs */
 189         env->regs[n] = ldl_p(mem_buf);
 190     } else if (n == 32) {    /* PC */
 191         env->regs[R_PC] = ldl_p(mem_buf);
 192     } else if (n < 49) {     /* Status regs */
 193         env->regs[n - 1] = ldl_p(mem_buf);
 194     }
 195
 196     return 4;
 197 }
 198
 199 static Property nios2_properties[] = {
 200     DEFINE_PROP_BOOL("mmu_present", Nios2CPU, mmu_present, true),
 201     /* ALTR,pid-num-bits */
 202     DEFINE_PROP_UINT32("mmu_pid_num_bits", Nios2CPU, pid_num_bits, 8),
 203     /* ALTR,tlb-num-ways */
 204     DEFINE_PROP_UINT32("mmu_tlb_num_ways", Nios2CPU, tlb_num_ways, 16),
 205     /* ALTR,tlb-num-entries */
 206     DEFINE_PROP_UINT32("mmu_pid_num_entries", Nios2CPU, tlb_num_entries, 256),
 207     DEFINE_PROP_END_OF_LIST(),
 208 };
 209
 210 #ifndef CONFIG_USER_ONLY
 211 #include "hw/core/sysemu-cpu-ops.h"
 212
 213 static const struct SysemuCPUOps nios2_sysemu_ops = {
 214     .get_phys_page_debug = nios2_cpu_get_phys_page_debug,
 215 };
 216 #endif
 217
 218 #include "hw/core/tcg-cpu-ops.h"
 219
 220 static const struct TCGCPUOps nios2_tcg_ops = {
 221     .initialize = nios2_tcg_init,
 222     .cpu_exec_interrupt = nios2_cpu_exec_interrupt,
 223     .tlb_fill = nios2_cpu_tlb_fill,
 224
 225 #ifndef CONFIG_USER_ONLY
 226     .do_interrupt = nios2_cpu_do_interrupt,
 227     .do_unaligned_access = nios2_cpu_do_unaligned_access,
 228 #endif /* !CONFIG_USER_ONLY */
 229 };
 230
 231 static void nios2_cpu_class_init(ObjectClass *oc, void *data)
 232 {
 233     DeviceClass *dc = DEVICE_CLASS(oc);
 234     CPUClass *cc = CPU_CLASS(oc);
 235     Nios2CPUClass *ncc = NIOS2_CPU_CLASS(oc);
 236
 237     device_class_set_parent_realize(dc, nios2_cpu_realizefn,
 238                                     &ncc->parent_realize);
 239     device_class_set_props(dc, nios2_properties);
 240     device_class_set_parent_reset(dc, nios2_cpu_reset, &ncc->parent_reset);
 241
 242     cc->class_by_name = nios2_cpu_class_by_name;
 243     cc->has_work = nios2_cpu_has_work;
 244     cc->dump_state = nios2_cpu_dump_state;
 245     cc->set_pc = nios2_cpu_set_pc;
 246     cc->disas_set_info = nios2_cpu_disas_set_info;
 247 #ifndef CONFIG_USER_ONLY
 248     cc->sysemu_ops = &nios2_sysemu_ops;
 249 #endif
 250     cc->gdb_read_register = nios2_cpu_gdb_read_register;
 251     cc->gdb_write_register = nios2_cpu_gdb_write_register;
 252     cc->gdb_num_core_regs = 49;
 253     cc->tcg_ops = &nios2_tcg_ops;
 254 }
 255
 256 static const TypeInfo nios2_cpu_type_info = {
 257     .name = TYPE_NIOS2_CPU,
 258     .parent = TYPE_CPU,
 259     .instance_size = sizeof(Nios2CPU),
 260     .instance_init = nios2_cpu_initfn,
 261     .class_size = sizeof(Nios2CPUClass),
 262     .class_init = nios2_cpu_class_init,
 263 };
 264
 265 static void nios2_cpu_register_types(void)
 266 {
 267     type_register_static(&nios2_cpu_type_info);
 268 }
 269
 270 type_init(nios2_cpu_register_types)