qemu/target/riscv/th_csr.c

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/*
* T-Head-specific CSRs.
*
* Copyright (c) 2024 VRULL GmbH
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "cpu_vendorid.h"
#define CSR_TH_SXSTATUS 0x5c0
/* TH_SXSTATUS bits */
#define TH_SXSTATUS_UCME BIT(16)
#define TH_SXSTATUS_MAEE BIT(21)
#define TH_SXSTATUS_THEADISAEE BIT(22)
typedef struct {
int csrno;
int (*insertion_test)(RISCVCPU *cpu);
riscv_csr_operations csr_ops;
} riscv_csr;
static RISCVException smode(CPURISCVState *env, int csrno)
{
if (riscv_has_ext(env, RVS)) {
return RISCV_EXCP_NONE;
}
return RISCV_EXCP_ILLEGAL_INST;
}
static int test_thead_mvendorid(RISCVCPU *cpu)
{
if (cpu->cfg.mvendorid != THEAD_VENDOR_ID) {
return -1;
}
return 0;
}
static RISCVException read_th_sxstatus(CPURISCVState *env, int csrno,
target_ulong *val)
{
/* We don't set MAEE here, because QEMU does not implement MAEE. */
*val = TH_SXSTATUS_UCME | TH_SXSTATUS_THEADISAEE;
return RISCV_EXCP_NONE;
}
static riscv_csr th_csr_list[] = {
{
.csrno = CSR_TH_SXSTATUS,
.insertion_test = test_thead_mvendorid,
.csr_ops = { "th.sxstatus", smode, read_th_sxstatus }
}
};
void th_register_custom_csrs(RISCVCPU *cpu)
{
for (size_t i = 0; i < ARRAY_SIZE(th_csr_list); i++) {
int csrno = th_csr_list[i].csrno;
riscv_csr_operations *csr_ops = &th_csr_list[i].csr_ops;
if (!th_csr_list[i].insertion_test(cpu)) {
riscv_set_csr_ops(csrno, csr_ops);
}
}
}