qemu-e2k/hw/core/register.c

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/*
* Register Definition API
*
* Copyright (c) 2016 Xilinx Inc.
* Copyright (c) 2013 Peter Crosthwaite <peter.crosthwaite@xilinx.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#include "qemu/osdep.h"
#include "hw/register.h"
#include "hw/qdev.h"
#include "qemu/log.h"
static inline void register_write_val(RegisterInfo *reg, uint64_t val)
{
g_assert(reg->data);
switch (reg->data_size) {
case 1:
*(uint8_t *)reg->data = val;
break;
case 2:
*(uint16_t *)reg->data = val;
break;
case 4:
*(uint32_t *)reg->data = val;
break;
case 8:
*(uint64_t *)reg->data = val;
break;
default:
g_assert_not_reached();
}
}
static inline uint64_t register_read_val(RegisterInfo *reg)
{
switch (reg->data_size) {
case 1:
return *(uint8_t *)reg->data;
case 2:
return *(uint16_t *)reg->data;
case 4:
return *(uint32_t *)reg->data;
case 8:
return *(uint64_t *)reg->data;
default:
g_assert_not_reached();
}
return 0; /* unreachable */
}
void register_write(RegisterInfo *reg, uint64_t val, uint64_t we,
const char *prefix, bool debug)
{
uint64_t old_val, new_val, test, no_w_mask;
const RegisterAccessInfo *ac;
assert(reg);
ac = reg->access;
if (!ac || !ac->name) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: write to undefined device state "
"(written value: %#" PRIx64 ")\n", prefix, val);
return;
}
old_val = reg->data ? register_read_val(reg) : ac->reset;
test = (old_val ^ val) & ac->rsvd;
if (test) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: change of value in reserved bit"
"fields: %#" PRIx64 ")\n", prefix, test);
}
test = val & ac->unimp;
if (test) {
qemu_log_mask(LOG_UNIMP,
"%s:%s writing %#" PRIx64 " to unimplemented bits:" \
" %#" PRIx64 "",
prefix, reg->access->name, val, ac->unimp);
}
/* Create the no write mask based on the read only, write to clear and
* reserved bit masks.
*/
no_w_mask = ac->ro | ac->w1c | ac->rsvd | ~we;
new_val = (val & ~no_w_mask) | (old_val & no_w_mask);
new_val &= ~(val & ac->w1c);
if (ac->pre_write) {
new_val = ac->pre_write(reg, new_val);
}
if (debug) {
qemu_log("%s:%s: write of value %#" PRIx64 "\n", prefix, ac->name,
new_val);
}
register_write_val(reg, new_val);
if (ac->post_write) {
ac->post_write(reg, new_val);
}
}
uint64_t register_read(RegisterInfo *reg, uint64_t re, const char* prefix,
bool debug)
{
uint64_t ret;
const RegisterAccessInfo *ac;
assert(reg);
ac = reg->access;
if (!ac || !ac->name) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: read from undefined device state\n",
prefix);
return 0;
}
ret = reg->data ? register_read_val(reg) : ac->reset;
register_write_val(reg, ret & ~(ac->cor & re));
/* Mask based on the read enable size */
ret &= re;
if (ac->post_read) {
ret = ac->post_read(reg, ret);
}
if (debug) {
qemu_log("%s:%s: read of value %#" PRIx64 "\n", prefix,
ac->name, ret);
}
return ret;
}
void register_reset(RegisterInfo *reg)
{
g_assert(reg);
if (!reg->data || !reg->access) {
return;
}
register_write_val(reg, reg->access->reset);
}