1/*
2 * RISC-V translation routines for the RISC-V Zawrs Extension.
3 *
4 * Copyright (c) 2022 Christoph Muellner, christoph.muellner@vrull.io
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
19static bool trans_wrs_sto(DisasContext *ctx, arg_wrs_sto *a)
20{
21    if (!ctx->cfg_ptr->ext_zawrs) {
22        return false;
23    }
24
25    /*
26     * The specification says:
27     * While stalled, an implementation is permitted to occasionally
28     * terminate the stall and complete execution for any reason.
29     *
30     * So let's just exit TB and return to the main loop.
31     */
32
33    /* Clear the load reservation  (if any).  */
34    tcg_gen_movi_tl(load_res, -1);
35
36    gen_update_pc(ctx, ctx->cur_insn_len);
37    tcg_gen_exit_tb(NULL, 0);
38    ctx->base.is_jmp = DISAS_NORETURN;
39
40    return true;
41}
42
43static bool trans_wrs_nto(DisasContext *ctx, arg_wrs_nto *a)
44{
45    if (!ctx->cfg_ptr->ext_zawrs) {
46        return false;
47    }
48
49    /*
50     * Depending on the mode of execution, mstatus.TW and hstatus.VTW, wrs.nto
51     * should raise an exception when the implementation-specific bounded time
52     * limit has expired. Our time limit is zero, so we either return
53     * immediately, as does our implementation of wrs.sto, or raise an
54     * exception, as handled by the wrs.nto helper.
55     */
56#ifndef CONFIG_USER_ONLY
57    gen_helper_wrs_nto(tcg_env);
58#endif
59
60    /* We only get here when helper_wrs_nto() doesn't raise an exception. */
61    return trans_wrs_sto(ctx, NULL);
62}
63