hw/core/register.c

   1 /*
   2  * Register Definition API
   3  *
   4  * Copyright (c) 2016 Xilinx Inc.
   5  * Copyright (c) 2013 Peter Crosthwaite <peter.crosthwaite@xilinx.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 #include "qemu/osdep.h"
  19 #include "hw/register.h"
  20 #include "hw/qdev.h"
  21 #include "qemu/log.h"
  22
  23 static inline void register_write_val(RegisterInfo *reg, uint64_t val)
  24 {
  25     g_assert(reg->data);
  26
  27     switch (reg->data_size) {
  28     case 1:
  29         *(uint8_t *)reg->data = val;
  30         break;
  31     case 2:
  32         *(uint16_t *)reg->data = val;
  33         break;
  34     case 4:
  35         *(uint32_t *)reg->data = val;
  36         break;
  37     case 8:
  38         *(uint64_t *)reg->data = val;
  39         break;
  40     default:
  41         g_assert_not_reached();
  42     }
  43 }
  44
  45 static inline uint64_t register_read_val(RegisterInfo *reg)
  46 {
  47     switch (reg->data_size) {
  48     case 1:
  49         return *(uint8_t *)reg->data;
  50     case 2:
  51         return *(uint16_t *)reg->data;
  52     case 4:
  53         return *(uint32_t *)reg->data;
  54     case 8:
  55         return *(uint64_t *)reg->data;
  56     default:
  57         g_assert_not_reached();
  58     }
  59     return 0; /* unreachable */
  60 }
  61
  62 static inline uint64_t register_enabled_mask(int data_size, unsigned size)
  63 {
  64     if (data_size < size) {
  65         size = data_size;
  66     }
  67
  68     return MAKE_64BIT_MASK(0, size * 8);
  69 }
  70
  71 void register_write(RegisterInfo *reg, uint64_t val, uint64_t we,
  72                     const char *prefix, bool debug)
  73 {
  74     uint64_t old_val, new_val, test, no_w_mask;
  75     const RegisterAccessInfo *ac;
  76
  77     assert(reg);
  78
  79     ac = reg->access;
  80
  81     if (!ac || !ac->name) {
  82         qemu_log_mask(LOG_GUEST_ERROR, "%s: write to undefined device state "
  83                       "(written value: %#" PRIx64 ")\n", prefix, val);
  84         return;
  85     }
  86
  87     old_val = reg->data ? register_read_val(reg) : ac->reset;
  88
  89     test = (old_val ^ val) & ac->rsvd;
  90     if (test) {
  91         qemu_log_mask(LOG_GUEST_ERROR, "%s: change of value in reserved bit"
  92                       "fields: %#" PRIx64 ")\n", prefix, test);
  93     }
  94
  95     test = val & ac->unimp;
  96     if (test) {
  97         qemu_log_mask(LOG_UNIMP,
  98                       "%s:%s writing %#" PRIx64 " to unimplemented bits:" \
  99                       " %#" PRIx64 "",
 100                       prefix, reg->access->name, val, ac->unimp);
 101     }
 102
 103     /* Create the no write mask based on the read only, write to clear and
 104      * reserved bit masks.
 105      */
 106     no_w_mask = ac->ro | ac->w1c | ac->rsvd | ~we;
 107     new_val = (val & ~no_w_mask) | (old_val & no_w_mask);
 108     new_val &= ~(val & ac->w1c);
 109
 110     if (ac->pre_write) {
 111         new_val = ac->pre_write(reg, new_val);
 112     }
 113
 114     if (debug) {
 115         qemu_log("%s:%s: write of value %#" PRIx64 "\n", prefix, ac->name,
 116                  new_val);
 117     }
 118
 119     register_write_val(reg, new_val);
 120
 121     if (ac->post_write) {
 122         ac->post_write(reg, new_val);
 123     }
 124 }
 125
 126 uint64_t register_read(RegisterInfo *reg, uint64_t re, const char* prefix,
 127                        bool debug)
 128 {
 129     uint64_t ret;
 130     const RegisterAccessInfo *ac;
 131
 132     assert(reg);
 133
 134     ac = reg->access;
 135     if (!ac || !ac->name) {
 136         qemu_log_mask(LOG_GUEST_ERROR, "%s: read from undefined device state\n",
 137                       prefix);
 138         return 0;
 139     }
 140
 141     ret = reg->data ? register_read_val(reg) : ac->reset;
 142
 143     register_write_val(reg, ret & ~(ac->cor & re));
 144
 145     /* Mask based on the read enable size */
 146     ret &= re;
 147
 148     if (ac->post_read) {
 149         ret = ac->post_read(reg, ret);
 150     }
 151
 152     if (debug) {
 153         qemu_log("%s:%s: read of value %#" PRIx64 "\n", prefix,
 154                  ac->name, ret);
 155     }
 156
 157     return ret;
 158 }
 159
 160 void register_reset(RegisterInfo *reg)
 161 {
 162     g_assert(reg);
 163
 164     if (!reg->data || !reg->access) {
 165         return;
 166     }
 167
 168     register_write_val(reg, reg->access->reset);
 169 }
 170
 171 void register_init(RegisterInfo *reg)
 172 {
 173     assert(reg);
 174
 175     if (!reg->data || !reg->access) {
 176         return;
 177     }
 178
 179     object_initialize((void *)reg, sizeof(*reg), TYPE_REGISTER);
 180 }
 181
 182 void register_write_memory(void *opaque, hwaddr addr,
 183                            uint64_t value, unsigned size)
 184 {
 185     RegisterInfoArray *reg_array = opaque;
 186     RegisterInfo *reg = NULL;
 187     uint64_t we;
 188     int i;
 189
 190     for (i = 0; i < reg_array->num_elements; i++) {
 191         if (reg_array->r[i]->access->addr == addr) {
 192             reg = reg_array->r[i];
 193             break;
 194         }
 195     }
 196
 197     if (!reg) {
 198         qemu_log_mask(LOG_GUEST_ERROR, "%s: write to unimplemented register " \
 199                       "at address: %#" PRIx64 "\n", reg_array->prefix, addr);
 200         return;
 201     }
 202
 203     /* Generate appropriate write enable mask */
 204     we = register_enabled_mask(reg->data_size, size);
 205
 206     register_write(reg, value, we, reg_array->prefix,
 207                    reg_array->debug);
 208 }
 209
 210 uint64_t register_read_memory(void *opaque, hwaddr addr,
 211                               unsigned size)
 212 {
 213     RegisterInfoArray *reg_array = opaque;
 214     RegisterInfo *reg = NULL;
 215     uint64_t read_val;
 216     uint64_t re;
 217     int i;
 218
 219     for (i = 0; i < reg_array->num_elements; i++) {
 220         if (reg_array->r[i]->access->addr == addr) {
 221             reg = reg_array->r[i];
 222             break;
 223         }
 224     }
 225
 226     if (!reg) {
 227         qemu_log_mask(LOG_GUEST_ERROR, "%s:  read to unimplemented register " \
 228                       "at address: %#" PRIx64 "\n", reg_array->prefix, addr);
 229         return 0;
 230     }
 231
 232     /* Generate appropriate read enable mask */
 233     re = register_enabled_mask(reg->data_size, size);
 234
 235     read_val = register_read(reg, re, reg_array->prefix,
 236                              reg_array->debug);
 237
 238     return extract64(read_val, 0, size * 8);
 239 }
 240
 241 RegisterInfoArray *register_init_block32(DeviceState *owner,
 242                                          const RegisterAccessInfo *rae,
 243                                          int num, RegisterInfo *ri,
 244                                          uint32_t *data,
 245                                          const MemoryRegionOps *ops,
 246                                          bool debug_enabled,
 247                                          uint64_t memory_size)
 248 {
 249     const char *device_prefix = object_get_typename(OBJECT(owner));
 250     RegisterInfoArray *r_array = g_new0(RegisterInfoArray, 1);
 251     int i;
 252
 253     r_array->r = g_new0(RegisterInfo *, num);
 254     r_array->num_elements = num;
 255     r_array->debug = debug_enabled;
 256     r_array->prefix = device_prefix;
 257
 258     for (i = 0; i < num; i++) {
 259         int index = rae[i].addr / 4;
 260         RegisterInfo *r = &ri[index];
 261
 262         *r = (RegisterInfo) {
 263             .data = &data[index],
 264             .data_size = sizeof(uint32_t),
 265             .access = &rae[i],
 266             .opaque = owner,
 267         };
 268         register_init(r);
 269
 270         r_array->r[i] = r;
 271     }
 272
 273     memory_region_init_io(&r_array->mem, OBJECT(owner), ops, r_array,
 274                           device_prefix, memory_size);
 275
 276     return r_array;
 277 }
 278
 279 void register_finalize_block(RegisterInfoArray *r_array)
 280 {
 281     object_unparent(OBJECT(&r_array->mem));
 282     g_free(r_array->r);
 283     g_free(r_array);
 284 }
 285
 286 static void register_class_init(ObjectClass *oc, void *data)
 287 {
 288     DeviceClass *dc = DEVICE_CLASS(oc);
 289
 290     /* Reason: needs to be wired up to work */
 291     dc->user_creatable = false;
 292 }
 293
 294 static const TypeInfo register_info = {
 295     .name  = TYPE_REGISTER,
 296     .parent = TYPE_DEVICE,
 297     .class_init = register_class_init,
 298 };
 299
 300 static void register_register_types(void)
 301 {
 302     type_register_static(&register_info);
 303 }
 304
 305 type_init(register_register_types)