hw/armv7m_nvic.c

   1 /*
   2  * ARM Nested Vectored Interrupt Controller
   3  *
   4  * Copyright (c) 2006-2007 CodeSourcery.
   5  * Written by Paul Brook
   6  *
   7  * This code is licenced under the GPL.
   8  *
   9  * The ARMv7M System controller is fairly tightly tied in with the
  10  * NVIC.  Much of that is also implemented here.
  11  */
  12
  13 #include "hw.h"
  14 #include "qemu-timer.h"
  15 #include "arm-misc.h"
  16
  17 /* 32 internal lines (16 used for system exceptions) plus 64 external
  18    interrupt lines.  */
  19 #define GIC_NIRQ 96
  20 #define NCPU 1
  21 #define NVIC 1
  22
  23 /* Only a single "CPU" interface is present.  */
  24 static inline int
  25 gic_get_current_cpu(void)
  26 {
  27     return 0;
  28 }
  29
  30 static uint32_t nvic_readl(void *opaque, uint32_t offset);
  31 static void nvic_writel(void *opaque, uint32_t offset, uint32_t value);
  32
  33 #include "arm_gic.c"
  34
  35 typedef struct {
  36     struct {
  37         uint32_t control;
  38         uint32_t reload;
  39         int64_t tick;
  40         QEMUTimer *timer;
  41     } systick;
  42     gic_state *gic;
  43 } nvic_state;
  44
  45 /* qemu timers run at 1GHz.   We want something closer to 1MHz.  */
  46 #define SYSTICK_SCALE 1000ULL
  47
  48 #define SYSTICK_ENABLE    (1 << 0)
  49 #define SYSTICK_TICKINT   (1 << 1)
  50 #define SYSTICK_CLKSOURCE (1 << 2)
  51 #define SYSTICK_COUNTFLAG (1 << 16)
  52
  53 int system_clock_scale;
  54
  55 /* Conversion factor from qemu timer to SysTick frequencies.  */
  56 static inline int64_t systick_scale(nvic_state *s)
  57 {
  58     if (s->systick.control & SYSTICK_CLKSOURCE)
  59         return system_clock_scale;
  60     else
  61         return 1000;
  62 }
  63
  64 static void systick_reload(nvic_state *s, int reset)
  65 {
  66     if (reset)
  67         s->systick.tick = qemu_get_clock(vm_clock);
  68     s->systick.tick += (s->systick.reload + 1) * systick_scale(s);
  69     qemu_mod_timer(s->systick.timer, s->systick.tick);
  70 }
  71
  72 static void systick_timer_tick(void * opaque)
  73 {
  74     nvic_state *s = (nvic_state *)opaque;
  75     s->systick.control |= SYSTICK_COUNTFLAG;
  76     if (s->systick.control & SYSTICK_TICKINT) {
  77         /* Trigger the interrupt.  */
  78         armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
  79     }
  80     if (s->systick.reload == 0) {
  81         s->systick.control &= ~SYSTICK_ENABLE;
  82     } else {
  83         systick_reload(s, 0);
  84     }
  85 }
  86
  87 /* The external routines use the hardware vector numbering, ie. the first
  88    IRQ is #16.  The internal GIC routines use #32 as the first IRQ.  */
  89 void armv7m_nvic_set_pending(void *opaque, int irq)
  90 {
  91     nvic_state *s = (nvic_state *)opaque;
  92     if (irq >= 16)
  93         irq += 16;
  94     gic_set_pending_private(s->gic, 0, irq);
  95 }
  96
  97 /* Make pending IRQ active.  */
  98 int armv7m_nvic_acknowledge_irq(void *opaque)
  99 {
 100     nvic_state *s = (nvic_state *)opaque;
 101     uint32_t irq;
 102
 103     irq = gic_acknowledge_irq(s->gic, 0);
 104     if (irq == 1023)
 105         cpu_abort(cpu_single_env, "Interrupt but no vector\n");
 106     if (irq >= 32)
 107         irq -= 16;
 108     return irq;
 109 }
 110
 111 void armv7m_nvic_complete_irq(void *opaque, int irq)
 112 {
 113     nvic_state *s = (nvic_state *)opaque;
 114     if (irq >= 16)
 115         irq += 16;
 116     gic_complete_irq(s->gic, 0, irq);
 117 }
 118
 119 static uint32_t nvic_readl(void *opaque, uint32_t offset)
 120 {
 121     nvic_state *s = (nvic_state *)opaque;
 122     uint32_t val;
 123     int irq;
 124
 125     switch (offset) {
 126     case 4: /* Interrupt Control Type.  */
 127         return (GIC_NIRQ / 32) - 1;
 128     case 0x10: /* SysTick Control and Status.  */
 129         val = s->systick.control;
 130         s->systick.control &= ~SYSTICK_COUNTFLAG;
 131         return val;
 132     case 0x14: /* SysTick Reload Value.  */
 133         return s->systick.reload;
 134     case 0x18: /* SysTick Current Value.  */
 135         {
 136             int64_t t;
 137             if ((s->systick.control & SYSTICK_ENABLE) == 0)
 138                 return 0;
 139             t = qemu_get_clock(vm_clock);
 140             if (t >= s->systick.tick)
 141                 return 0;
 142             val = ((s->systick.tick - (t + 1)) / systick_scale(s)) + 1;
 143             /* The interrupt in triggered when the timer reaches zero.
 144                However the counter is not reloaded until the next clock
 145                tick.  This is a hack to return zero during the first tick.  */
 146             if (val > s->systick.reload)
 147                 val = 0;
 148             return val;
 149         }
 150     case 0x1c: /* SysTick Calibration Value.  */
 151         return 10000;
 152     case 0xd00: /* CPUID Base.  */
 153         return cpu_single_env->cp15.c0_cpuid;
 154     case 0xd04: /* Interrypt Control State.  */
 155         /* VECTACTIVE */
 156         val = s->gic->running_irq[0];
 157         if (val == 1023) {
 158             val = 0;
 159         } else if (val >= 32) {
 160             val -= 16;
 161         }
 162         /* RETTOBASE */
 163         if (s->gic->running_irq[0] == 1023
 164                 || s->gic->last_active[s->gic->running_irq[0]][0] == 1023) {
 165             val |= (1 << 11);
 166         }
 167         /* VECTPENDING */
 168         if (s->gic->current_pending[0] != 1023)
 169             val |= (s->gic->current_pending[0] << 12);
 170         /* ISRPENDING */
 171         for (irq = 32; irq < GIC_NIRQ; irq++) {
 172             if (s->gic->irq_state[irq].pending) {
 173                 val |= (1 << 22);
 174                 break;
 175             }
 176         }
 177         /* PENDSTSET */
 178         if (s->gic->irq_state[ARMV7M_EXCP_SYSTICK].pending)
 179             val |= (1 << 26);
 180         /* PENDSVSET */
 181         if (s->gic->irq_state[ARMV7M_EXCP_PENDSV].pending)
 182             val |= (1 << 28);
 183         /* NMIPENDSET */
 184         if (s->gic->irq_state[ARMV7M_EXCP_NMI].pending)
 185             val |= (1 << 31);
 186         return val;
 187     case 0xd08: /* Vector Table Offset.  */
 188         return cpu_single_env->v7m.vecbase;
 189     case 0xd0c: /* Application Interrupt/Reset Control.  */
 190         return 0xfa05000;
 191     case 0xd10: /* System Control.  */
 192         /* TODO: Implement SLEEPONEXIT.  */
 193         return 0;
 194     case 0xd14: /* Configuration Control.  */
 195         /* TODO: Implement Configuration Control bits.  */
 196         return 0;
 197     case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority.  */
 198         irq = offset - 0xd14;
 199         val = 0;
 200         val = s->gic->priority1[irq++][0];
 201         val = s->gic->priority1[irq++][0] << 8;
 202         val = s->gic->priority1[irq++][0] << 16;
 203         val = s->gic->priority1[irq][0] << 24;
 204         return val;
 205     case 0xd24: /* System Handler Status.  */
 206         val = 0;
 207         if (s->gic->irq_state[ARMV7M_EXCP_MEM].active) val |= (1 << 0);
 208         if (s->gic->irq_state[ARMV7M_EXCP_BUS].active) val |= (1 << 1);
 209         if (s->gic->irq_state[ARMV7M_EXCP_USAGE].active) val |= (1 << 3);
 210         if (s->gic->irq_state[ARMV7M_EXCP_SVC].active) val |= (1 << 7);
 211         if (s->gic->irq_state[ARMV7M_EXCP_DEBUG].active) val |= (1 << 8);
 212         if (s->gic->irq_state[ARMV7M_EXCP_PENDSV].active) val |= (1 << 10);
 213         if (s->gic->irq_state[ARMV7M_EXCP_SYSTICK].active) val |= (1 << 11);
 214         if (s->gic->irq_state[ARMV7M_EXCP_USAGE].pending) val |= (1 << 12);
 215         if (s->gic->irq_state[ARMV7M_EXCP_MEM].pending) val |= (1 << 13);
 216         if (s->gic->irq_state[ARMV7M_EXCP_BUS].pending) val |= (1 << 14);
 217         if (s->gic->irq_state[ARMV7M_EXCP_SVC].pending) val |= (1 << 15);
 218         if (s->gic->irq_state[ARMV7M_EXCP_MEM].enabled) val |= (1 << 16);
 219         if (s->gic->irq_state[ARMV7M_EXCP_BUS].enabled) val |= (1 << 17);
 220         if (s->gic->irq_state[ARMV7M_EXCP_USAGE].enabled) val |= (1 << 18);
 221         return val;
 222     case 0xd28: /* Configurable Fault Status.  */
 223         /* TODO: Implement Fault Status.  */
 224         cpu_abort(cpu_single_env,
 225                   "Not implemented: Configurable Fault Status.");
 226         return 0;
 227     case 0xd2c: /* Hard Fault Status.  */
 228     case 0xd30: /* Debug Fault Status.  */
 229     case 0xd34: /* Mem Manage Address.  */
 230     case 0xd38: /* Bus Fault Address.  */
 231     case 0xd3c: /* Aux Fault Status.  */
 232         /* TODO: Implement fault status registers.  */
 233         goto bad_reg;
 234     case 0xd40: /* PFR0.  */
 235         return 0x00000030;
 236     case 0xd44: /* PRF1.  */
 237         return 0x00000200;
 238     case 0xd48: /* DFR0.  */
 239         return 0x00100000;
 240     case 0xd4c: /* AFR0.  */
 241         return 0x00000000;
 242     case 0xd50: /* MMFR0.  */
 243         return 0x00000030;
 244     case 0xd54: /* MMFR1.  */
 245         return 0x00000000;
 246     case 0xd58: /* MMFR2.  */
 247         return 0x00000000;
 248     case 0xd5c: /* MMFR3.  */
 249         return 0x00000000;
 250     case 0xd60: /* ISAR0.  */
 251         return 0x01141110;
 252     case 0xd64: /* ISAR1.  */
 253         return 0x02111000;
 254     case 0xd68: /* ISAR2.  */
 255         return 0x21112231;
 256     case 0xd6c: /* ISAR3.  */
 257         return 0x01111110;
 258     case 0xd70: /* ISAR4.  */
 259         return 0x01310102;
 260     /* TODO: Implement debug registers.  */
 261     default:
 262     bad_reg:
 263         cpu_abort(cpu_single_env, "NVIC: Bad read offset 0x%x\n", offset);
 264     }
 265 }
 266
 267 static void nvic_writel(void *opaque, uint32_t offset, uint32_t value)
 268 {
 269     nvic_state *s = (nvic_state *)opaque;
 270     uint32_t oldval;
 271     switch (offset) {
 272     case 0x10: /* SysTick Control and Status.  */
 273         oldval = s->systick.control;
 274         s->systick.control &= 0xfffffff8;
 275         s->systick.control |= value & 7;
 276         if ((oldval ^ value) & SYSTICK_ENABLE) {
 277             int64_t now = qemu_get_clock(vm_clock);
 278             if (value & SYSTICK_ENABLE) {
 279                 if (s->systick.tick) {
 280                     s->systick.tick += now;
 281                     qemu_mod_timer(s->systick.timer, s->systick.tick);
 282                 } else {
 283                     systick_reload(s, 1);
 284                 }
 285             } else {
 286                 qemu_del_timer(s->systick.timer);
 287                 s->systick.tick -= now;
 288                 if (s->systick.tick < 0)
 289                   s->systick.tick = 0;
 290             }
 291         } else if ((oldval ^ value) & SYSTICK_CLKSOURCE) {
 292             /* This is a hack. Force the timer to be reloaded
 293                when the reference clock is changed.  */
 294             systick_reload(s, 1);
 295         }
 296         break;
 297     case 0x14: /* SysTick Reload Value.  */
 298         s->systick.reload = value;
 299         break;
 300     case 0x18: /* SysTick Current Value.  Writes reload the timer.  */
 301         systick_reload(s, 1);
 302         s->systick.control &= ~SYSTICK_COUNTFLAG;
 303         break;
 304     case 0xd04: /* Interrupt Control State.  */
 305         if (value & (1 << 31)) {
 306             armv7m_nvic_set_pending(s, ARMV7M_EXCP_NMI);
 307         }
 308         if (value & (1 << 28)) {
 309             armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV);
 310         } else if (value & (1 << 27)) {
 311             s->gic->irq_state[ARMV7M_EXCP_PENDSV].pending = 0;
 312             gic_update(s->gic);
 313         }
 314         if (value & (1 << 26)) {
 315             armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
 316         } else if (value & (1 << 25)) {
 317             s->gic->irq_state[ARMV7M_EXCP_SYSTICK].pending = 0;
 318             gic_update(s->gic);
 319         }
 320         break;
 321     case 0xd08: /* Vector Table Offset.  */
 322         cpu_single_env->v7m.vecbase = value & 0xffffff80;
 323         break;
 324     case 0xd0c: /* Application Interrupt/Reset Control.  */
 325         if ((value >> 16) == 0x05fa) {
 326             if (value & 2) {
 327                 cpu_abort(cpu_single_env, "VECTCLRACTIVE not implemented");
 328             }
 329             if (value & 5) {
 330                 cpu_abort(cpu_single_env, "System reset");
 331             }
 332         }
 333         break;
 334     case 0xd10: /* System Control.  */
 335     case 0xd14: /* Configuration Control.  */
 336         /* TODO: Implement control registers.  */
 337         goto bad_reg;
 338     case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority.  */
 339         {
 340             int irq;
 341             irq = offset - 0xd14;
 342             s->gic->priority1[irq++][0] = value & 0xff;
 343             s->gic->priority1[irq++][0] = (value >> 8) & 0xff;
 344             s->gic->priority1[irq++][0] = (value >> 16) & 0xff;
 345             s->gic->priority1[irq][0] = (value >> 24) & 0xff;
 346             gic_update(s->gic);
 347         }
 348         break;
 349     case 0xd24: /* System Handler Control.  */
 350         /* TODO: Real hardware allows you to set/clear the active bits
 351            under some circumstances.  We don't implement this.  */
 352         s->gic->irq_state[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0;
 353         s->gic->irq_state[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0;
 354         s->gic->irq_state[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0;
 355         break;
 356     case 0xd28: /* Configurable Fault Status.  */
 357     case 0xd2c: /* Hard Fault Status.  */
 358     case 0xd30: /* Debug Fault Status.  */
 359     case 0xd34: /* Mem Manage Address.  */
 360     case 0xd38: /* Bus Fault Address.  */
 361     case 0xd3c: /* Aux Fault Status.  */
 362         goto bad_reg;
 363     default:
 364     bad_reg:
 365         cpu_abort(cpu_single_env, "NVIC: Bad write offset 0x%x\n", offset);
 366     }
 367 }
 368
 369 static void nvic_save(QEMUFile *f, void *opaque)
 370 {
 371     nvic_state *s = (nvic_state *)opaque;
 372
 373     qemu_put_be32(f, s->systick.control);
 374     qemu_put_be32(f, s->systick.reload);
 375     qemu_put_be64(f, s->systick.tick);
 376     qemu_put_timer(f, s->systick.timer);
 377 }
 378
 379 static int nvic_load(QEMUFile *f, void *opaque, int version_id)
 380 {
 381     nvic_state *s = (nvic_state *)opaque;
 382
 383     if (version_id != 1)
 384         return -EINVAL;
 385
 386     s->systick.control = qemu_get_be32(f);
 387     s->systick.reload = qemu_get_be32(f);
 388     s->systick.tick = qemu_get_be64(f);
 389     qemu_get_timer(f, s->systick.timer);
 390
 391     return 0;
 392 }
 393
 394 qemu_irq *armv7m_nvic_init(CPUState *env)
 395 {
 396     nvic_state *s;
 397     qemu_irq *parent;
 398
 399     parent = arm_pic_init_cpu(env);
 400     s = (nvic_state *)qemu_mallocz(sizeof(nvic_state));
 401     s->gic = gic_init(0xe000e000, &parent[ARM_PIC_CPU_IRQ]);
 402     s->gic->nvic = s;
 403     s->systick.timer = qemu_new_timer(vm_clock, systick_timer_tick, s);
 404     if (env->v7m.nvic)
 405         cpu_abort(env, "CPU can only have one NVIC\n");
 406     env->v7m.nvic = s;
 407     register_savevm("armv7m_nvic", -1, 1, nvic_save, nvic_load, s);
 408     return s->gic->in;
 409 }