hw/etraxfs_pic.c

   1 /*
   2  * QEMU ETRAX Interrupt Controller.
   3  *
   4  * Copyright (c) 2008 Edgar E. Iglesias, Axis Communications AB.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include "hw.h"
  27 #include "etraxfs.h"
  28
  29 #define D(x)
  30
  31 struct fs_pic_state_t
  32 {
  33         CPUState *env;
  34
  35         uint32_t rw_mask;
  36         /* Active interrupt lines.  */
  37         uint32_t r_vect;
  38         /* Active lines, gated through the mask.  */
  39         uint32_t r_masked_vect;
  40         uint32_t r_nmi;
  41         uint32_t r_guru;
  42 };
  43
  44 static void pic_update(struct fs_pic_state_t *fs)
  45 {
  46         CPUState *env = fs->env;
  47         int i;
  48         uint32_t vector = 0;
  49
  50         fs->r_masked_vect = fs->r_vect & fs->rw_mask;
  51
  52         /* The ETRAX interrupt controller signals interrupts to teh core
  53            through an interrupt request wire and an irq vector bus. If
  54            multiple interrupts are simultaneously active it chooses vector
  55            0x30 and lets the sw choose the priorities.  */
  56         if (fs->r_masked_vect) {
  57                 uint32_t mv = fs->r_masked_vect;
  58                 for (i = 0; i < 31; i++) {
  59                         if (mv & 1) {
  60                                 vector = 0x31 + i;
  61                                 /* Check for multiple interrupts.  */
  62                                 if (mv > 1)
  63                                         vector = 0x30;
  64                                 break;
  65                         }
  66                         mv >>= 1;
  67                 }
  68                 if (vector) {
  69                         env->interrupt_vector = vector;
  70                         D(printf("%s vector=%x\n", __func__, vector));
  71                         cpu_interrupt(env, CPU_INTERRUPT_HARD);
  72                 }
  73         } else {
  74                 env->interrupt_vector = 0;
  75                 cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
  76                 D(printf("%s reset irqs\n", __func__));
  77         }
  78 }
  79
  80 static uint32_t pic_readl (void *opaque, target_phys_addr_t addr)
  81 {
  82         struct fs_pic_state_t *fs = opaque;
  83         uint32_t rval;
  84
  85         switch (addr)
  86         {
  87                 case 0x0:
  88                         rval = fs->rw_mask;
  89                         break;
  90                 case 0x4:
  91                         rval = fs->r_vect;
  92                         break;
  93                 case 0x8:
  94                         rval = fs->r_masked_vect;
  95                         break;
  96                 case 0xc:
  97                         rval = fs->r_nmi;
  98                         break;
  99                 case 0x10:
 100                         rval = fs->r_guru;
 101                         break;
 102                 default:
 103                         cpu_abort(fs->env, "invalid PIC register.\n");
 104                         break;
 105
 106         }
 107         D(printf("%s %x=%x\n", __func__, addr, rval));
 108         return rval;
 109 }
 110
 111 static void
 112 pic_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 113 {
 114         struct fs_pic_state_t *fs = opaque;
 115         D(printf("%s addr=%x val=%x\n", __func__, addr, value));
 116         switch (addr)
 117         {
 118                 case 0x0:
 119                         fs->rw_mask = value;
 120                         pic_update(fs);
 121                         break;
 122                 default:
 123                         cpu_abort(fs->env, "invalid PIC register.\n");
 124                         break;
 125         }
 126 }
 127
 128 static CPUReadMemoryFunc *pic_read[] = {
 129         NULL, NULL,
 130         &pic_readl,
 131 };
 132
 133 static CPUWriteMemoryFunc *pic_write[] = {
 134         NULL, NULL,
 135         &pic_writel,
 136 };
 137
 138 void pic_info(void)
 139 {
 140 }
 141
 142 void irq_info(void)
 143 {
 144 }
 145
 146 static void irq_handler(void *opaque, int irq, int level)
 147 {
 148         struct fs_pic_state_t *fs = (void *)opaque;
 149
 150         D(printf("%s irq=%d level=%d mask=%x v=%x mv=%x\n",
 151                  __func__, irq, level,
 152                  fs->rw_mask, fs->r_vect, fs->r_masked_vect));
 153
 154         irq -= 1;
 155         fs->r_vect &= ~(1 << irq);
 156         fs->r_vect |= (!!level << irq);
 157
 158         pic_update(fs);
 159 }
 160
 161 static void nmi_handler(void *opaque, int irq, int level)
 162 {
 163         struct fs_pic_state_t *fs = (void *)opaque;
 164         CPUState *env = fs->env;
 165         uint32_t mask;
 166
 167         mask = 1 << irq;
 168         if (level)
 169                 fs->r_nmi |= mask;
 170         else
 171                 fs->r_nmi &= ~mask;
 172
 173         if (fs->r_nmi)
 174                 cpu_interrupt(env, CPU_INTERRUPT_NMI);
 175         else
 176                 cpu_reset_interrupt(env, CPU_INTERRUPT_NMI);
 177 }
 178
 179 static void guru_handler(void *opaque, int irq, int level)
 180 {
 181         struct fs_pic_state_t *fs = (void *)opaque;
 182         CPUState *env = fs->env;
 183         cpu_abort(env, "%s unsupported exception\n", __func__);
 184
 185 }
 186
 187 struct etraxfs_pic *etraxfs_pic_init(CPUState *env, target_phys_addr_t base)
 188 {
 189         struct fs_pic_state_t *fs = NULL;
 190         struct etraxfs_pic *pic = NULL;
 191         int intr_vect_regs;
 192
 193         pic = qemu_mallocz(sizeof *pic);
 194         pic->internal = fs = qemu_mallocz(sizeof *fs);
 195         if (!fs || !pic)
 196                 goto err;
 197
 198         fs->env = env;
 199         pic->irq = qemu_allocate_irqs(irq_handler, fs, 30);
 200         pic->nmi = qemu_allocate_irqs(nmi_handler, fs, 2);
 201         pic->guru = qemu_allocate_irqs(guru_handler, fs, 1);
 202
 203         intr_vect_regs = cpu_register_io_memory(0, pic_read, pic_write, fs);
 204         cpu_register_physical_memory(base, 0x14, intr_vect_regs);
 205
 206         return pic;
 207   err:
 208         free(pic);
 209         free(fs);
 210         return NULL;
 211 }