hw/pl190.c

   1 /*
   2  * Arm PrimeCell PL190 Vector Interrupt Controller
   3  *
   4  * Copyright (c) 2006 CodeSourcery.
   5  * Written by Paul Brook
   6  *
   7  * This code is licenced under the GPL.
   8  */
   9
  10 #include "hw.h"
  11 #include "primecell.h"
  12 #include "arm-misc.h"
  13
  14 /* The number of virtual priority levels.  16 user vectors plus the
  15    unvectored IRQ.  Chained interrupts would require an additional level
  16    if implemented.  */
  17
  18 #define PL190_NUM_PRIO 17
  19
  20 typedef struct {
  21     uint32_t base;
  22     DisplayState *ds;
  23     uint32_t level;
  24     uint32_t soft_level;
  25     uint32_t irq_enable;
  26     uint32_t fiq_select;
  27     uint32_t default_addr;
  28     uint8_t vect_control[16];
  29     uint32_t vect_addr[PL190_NUM_PRIO];
  30     /* Mask containing interrupts with higher priority than this one.  */
  31     uint32_t prio_mask[PL190_NUM_PRIO + 1];
  32     int protected;
  33     /* Current priority level.  */
  34     int priority;
  35     int prev_prio[PL190_NUM_PRIO];
  36     qemu_irq irq;
  37     qemu_irq fiq;
  38 } pl190_state;
  39
  40 static const unsigned char pl190_id[] =
  41 { 0x90, 0x11, 0x04, 0x00, 0x0D, 0xf0, 0x05, 0xb1 };
  42
  43 static inline uint32_t pl190_irq_level(pl190_state *s)
  44 {
  45     return (s->level | s->soft_level) & s->irq_enable & ~s->fiq_select;
  46 }
  47
  48 /* Update interrupts.  */
  49 static void pl190_update(pl190_state *s)
  50 {
  51     uint32_t level = pl190_irq_level(s);
  52     int set;
  53
  54     set = (level & s->prio_mask[s->priority]) != 0;
  55     qemu_set_irq(s->irq, set);
  56     set = ((s->level | s->soft_level) & s->fiq_select) != 0;
  57     qemu_set_irq(s->fiq, set);
  58 }
  59
  60 static void pl190_set_irq(void *opaque, int irq, int level)
  61 {
  62     pl190_state *s = (pl190_state *)opaque;
  63
  64     if (level)
  65         s->level |= 1u << irq;
  66     else
  67         s->level &= ~(1u << irq);
  68     pl190_update(s);
  69 }
  70
  71 static void pl190_update_vectors(pl190_state *s)
  72 {
  73     uint32_t mask;
  74     int i;
  75     int n;
  76
  77     mask = 0;
  78     for (i = 0; i < 16; i++)
  79       {
  80         s->prio_mask[i] = mask;
  81         if (s->vect_control[i] & 0x20)
  82           {
  83             n = s->vect_control[i] & 0x1f;
  84             mask |= 1 << n;
  85           }
  86       }
  87     s->prio_mask[16] = mask;
  88     pl190_update(s);
  89 }
  90
  91 static uint32_t pl190_read(void *opaque, target_phys_addr_t offset)
  92 {
  93     pl190_state *s = (pl190_state *)opaque;
  94     int i;
  95
  96     offset -= s->base;
  97     if (offset >= 0xfe0 && offset < 0x1000) {
  98         return pl190_id[(offset - 0xfe0) >> 2];
  99     }
 100     if (offset >= 0x100 && offset < 0x140) {
 101         return s->vect_addr[(offset - 0x100) >> 2];
 102     }
 103     if (offset >= 0x200 && offset < 0x240) {
 104         return s->vect_control[(offset - 0x200) >> 2];
 105     }
 106     switch (offset >> 2) {
 107     case 0: /* IRQSTATUS */
 108         return pl190_irq_level(s);
 109     case 1: /* FIQSATUS */
 110         return (s->level | s->soft_level) & s->fiq_select;
 111     case 2: /* RAWINTR */
 112         return s->level | s->soft_level;
 113     case 3: /* INTSELECT */
 114         return s->fiq_select;
 115     case 4: /* INTENABLE */
 116         return s->irq_enable;
 117     case 6: /* SOFTINT */
 118         return s->soft_level;
 119     case 8: /* PROTECTION */
 120         return s->protected;
 121     case 12: /* VECTADDR */
 122         /* Read vector address at the start of an ISR.  Increases the
 123            current priority level to that of the current interrupt.  */
 124         for (i = 0; i < s->priority; i++)
 125           {
 126             if ((s->level | s->soft_level) & s->prio_mask[i])
 127               break;
 128           }
 129         /* Reading this value with no pending interrupts is undefined.
 130            We return the default address.  */
 131         if (i == PL190_NUM_PRIO)
 132           return s->vect_addr[16];
 133         if (i < s->priority)
 134           {
 135             s->prev_prio[i] = s->priority;
 136             s->priority = i;
 137             pl190_update(s);
 138           }
 139         return s->vect_addr[s->priority];
 140     case 13: /* DEFVECTADDR */
 141         return s->vect_addr[16];
 142     default:
 143         cpu_abort (cpu_single_env, "pl190_read: Bad offset %x\n", (int)offset);
 144         return 0;
 145     }
 146 }
 147
 148 static void pl190_write(void *opaque, target_phys_addr_t offset, uint32_t val)
 149 {
 150     pl190_state *s = (pl190_state *)opaque;
 151
 152     offset -= s->base;
 153     if (offset >= 0x100 && offset < 0x140) {
 154         s->vect_addr[(offset - 0x100) >> 2] = val;
 155         pl190_update_vectors(s);
 156         return;
 157     }
 158     if (offset >= 0x200 && offset < 0x240) {
 159         s->vect_control[(offset - 0x200) >> 2] = val;
 160         pl190_update_vectors(s);
 161         return;
 162     }
 163     switch (offset >> 2) {
 164     case 0: /* SELECT */
 165         /* This is a readonly register, but linux tries to write to it
 166            anyway.  Ignore the write.  */
 167         break;
 168     case 3: /* INTSELECT */
 169         s->fiq_select = val;
 170         break;
 171     case 4: /* INTENABLE */
 172         s->irq_enable |= val;
 173         break;
 174     case 5: /* INTENCLEAR */
 175         s->irq_enable &= ~val;
 176         break;
 177     case 6: /* SOFTINT */
 178         s->soft_level |= val;
 179         break;
 180     case 7: /* SOFTINTCLEAR */
 181         s->soft_level &= ~val;
 182         break;
 183     case 8: /* PROTECTION */
 184         /* TODO: Protection (supervisor only access) is not implemented.  */
 185         s->protected = val & 1;
 186         break;
 187     case 12: /* VECTADDR */
 188         /* Restore the previous priority level.  The value written is
 189            ignored.  */
 190         if (s->priority < PL190_NUM_PRIO)
 191             s->priority = s->prev_prio[s->priority];
 192         break;
 193     case 13: /* DEFVECTADDR */
 194         s->default_addr = val;
 195         break;
 196     case 0xc0: /* ITCR */
 197         if (val)
 198             cpu_abort(cpu_single_env, "pl190: Test mode not implemented\n");
 199         break;
 200     default:
 201         cpu_abort(cpu_single_env, "pl190_write: Bad offset %x\n", (int)offset);
 202         return;
 203     }
 204     pl190_update(s);
 205 }
 206
 207 static CPUReadMemoryFunc *pl190_readfn[] = {
 208    pl190_read,
 209    pl190_read,
 210    pl190_read
 211 };
 212
 213 static CPUWriteMemoryFunc *pl190_writefn[] = {
 214    pl190_write,
 215    pl190_write,
 216    pl190_write
 217 };
 218
 219 void pl190_reset(pl190_state *s)
 220 {
 221   int i;
 222
 223   for (i = 0; i < 16; i++)
 224     {
 225       s->vect_addr[i] = 0;
 226       s->vect_control[i] = 0;
 227     }
 228   s->vect_addr[16] = 0;
 229   s->prio_mask[17] = 0xffffffff;
 230   s->priority = PL190_NUM_PRIO;
 231   pl190_update_vectors(s);
 232 }
 233
 234 qemu_irq *pl190_init(uint32_t base, qemu_irq irq, qemu_irq fiq)
 235 {
 236     pl190_state *s;
 237     qemu_irq *qi;
 238     int iomemtype;
 239
 240     s = (pl190_state *)qemu_mallocz(sizeof(pl190_state));
 241     iomemtype = cpu_register_io_memory(0, pl190_readfn,
 242                                        pl190_writefn, s);
 243     cpu_register_physical_memory(base, 0x00001000, iomemtype);
 244     qi = qemu_allocate_irqs(pl190_set_irq, s, 32);
 245     s->base = base;
 246     s->irq = irq;
 247     s->fiq = fiq;
 248     pl190_reset(s);
 249     /* ??? Save/restore.  */
 250     return qi;
 251 }