1 /*
2 * T-Head-specific CSRs.
3 *
4 * Copyright (c) 2024 VRULL GmbH
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2 or later, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #include "qemu/osdep.h"
20 #include "cpu.h"
21 #include "cpu_vendorid.h"
22
23 #define CSR_TH_SXSTATUS 0x5c0
24
25 /* TH_SXSTATUS bits */
26 #define TH_SXSTATUS_UCME BIT(16)
27 #define TH_SXSTATUS_MAEE BIT(21)
28 #define TH_SXSTATUS_THEADISAEE BIT(22)
29
smode(CPURISCVState * env,int csrno)30 static RISCVException smode(CPURISCVState *env, int csrno)
31 {
32 if (riscv_has_ext(env, RVS)) {
33 return RISCV_EXCP_NONE;
34 }
35
36 return RISCV_EXCP_ILLEGAL_INST;
37 }
38
test_thead_mvendorid(RISCVCPU * cpu)39 static bool test_thead_mvendorid(RISCVCPU *cpu)
40 {
41 return cpu->cfg.mvendorid == THEAD_VENDOR_ID;
42 }
43
read_th_sxstatus(CPURISCVState * env,int csrno,target_ulong * val)44 static RISCVException read_th_sxstatus(CPURISCVState *env, int csrno,
45 target_ulong *val)
46 {
47 /* We don't set MAEE here, because QEMU does not implement MAEE. */
48 *val = TH_SXSTATUS_UCME | TH_SXSTATUS_THEADISAEE;
49 return RISCV_EXCP_NONE;
50 }
51
52 const RISCVCSR th_csr_list[] = {
53 {
54 .csrno = CSR_TH_SXSTATUS,
55 .insertion_test = test_thead_mvendorid,
56 .csr_ops = { "th.sxstatus", smode, read_th_sxstatus }
57 },
58 { }
59 };
60