xref: /openbmc/qemu/target/hppa/sys_helper.c (revision b887b6b7)
1 /*
2  * Helpers for HPPA system instructions.
3  *
4  * Copyright (c) 2016 Richard Henderson <rth@twiddle.net>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/exec-all.h"
23 #include "exec/helper-proto.h"
24 #include "qemu/timer.h"
25 #include "sysemu/runstate.h"
26 #include "sysemu/sysemu.h"
27 #include "chardev/char-fe.h"
28 
29 void HELPER(write_interval_timer)(CPUHPPAState *env, target_ulong val)
30 {
31     HPPACPU *cpu = env_archcpu(env);
32     uint64_t current = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
33     uint64_t timeout;
34 
35     /*
36      * Even in 64-bit mode, the comparator is always 32-bit.  But the
37      * value we expose to the guest is 1/4 of the speed of the clock,
38      * so moosh in 34 bits.
39      */
40     timeout = deposit64(current, 0, 34, (uint64_t)val << 2);
41 
42     /* If the mooshing puts the clock in the past, advance to next round.  */
43     if (timeout < current + 1000) {
44         timeout += 1ULL << 34;
45     }
46 
47     cpu->env.cr[CR_IT] = timeout;
48     timer_mod(cpu->alarm_timer, timeout);
49 }
50 
51 void HELPER(halt)(CPUHPPAState *env)
52 {
53     qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
54     helper_excp(env, EXCP_HLT);
55 }
56 
57 void HELPER(reset)(CPUHPPAState *env)
58 {
59     qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
60     helper_excp(env, EXCP_HLT);
61 }
62 
63 target_ulong HELPER(swap_system_mask)(CPUHPPAState *env, target_ulong nsm)
64 {
65     target_ulong psw = env->psw;
66     /*
67      * Setting the PSW Q bit to 1, if it was not already 1, is an
68      * undefined operation.
69      *
70      * However, HP-UX 10.20 does this with the SSM instruction.
71      * Tested this on HP9000/712 and HP9000/785/C3750 and both
72      * machines set the Q bit from 0 to 1 without an exception,
73      * so let this go without comment.
74      */
75     env->psw = (psw & ~PSW_SM) | (nsm & PSW_SM);
76     return psw & PSW_SM;
77 }
78 
79 void HELPER(rfi)(CPUHPPAState *env)
80 {
81     uint64_t mask;
82 
83     cpu_hppa_put_psw(env, env->cr[CR_IPSW]);
84 
85     /*
86      * For pa2.0, IIASQ is the top bits of the virtual address.
87      * To recreate the space identifier, remove the offset bits.
88      * For pa1.x, the mask reduces to no change to space.
89      */
90     mask = gva_offset_mask(env->psw);
91 
92     env->iaoq_f = env->cr[CR_IIAOQ];
93     env->iaoq_b = env->cr_back[1];
94     env->iasq_f = (env->cr[CR_IIASQ] << 32) & ~(env->iaoq_f & mask);
95     env->iasq_b = (env->cr_back[0] << 32) & ~(env->iaoq_b & mask);
96 }
97 
98 static void getshadowregs(CPUHPPAState *env)
99 {
100     env->gr[1] = env->shadow[0];
101     env->gr[8] = env->shadow[1];
102     env->gr[9] = env->shadow[2];
103     env->gr[16] = env->shadow[3];
104     env->gr[17] = env->shadow[4];
105     env->gr[24] = env->shadow[5];
106     env->gr[25] = env->shadow[6];
107 }
108 
109 void HELPER(rfi_r)(CPUHPPAState *env)
110 {
111     getshadowregs(env);
112     helper_rfi(env);
113 }
114 
115 #ifndef CONFIG_USER_ONLY
116 /*
117  * diag_console_output() is a helper function used during the initial bootup
118  * process of the SeaBIOS-hppa firmware.  During the bootup phase, addresses of
119  * serial ports on e.g. PCI busses are unknown and most other devices haven't
120  * been initialized and configured yet.  With help of a simple "diag" assembler
121  * instruction and an ASCII character code in register %r26 firmware can easily
122  * print debug output without any dependencies to the first serial port and use
123  * that as serial console.
124  */
125 void HELPER(diag_console_output)(CPUHPPAState *env)
126 {
127     CharBackend *serial_backend;
128     Chardev *serial_port;
129     unsigned char c;
130 
131     /* find first serial port */
132     serial_port = serial_hd(0);
133     if (!serial_port) {
134         return;
135     }
136 
137     /* get serial_backend for the serial port */
138     serial_backend = serial_port->be;
139     if (!serial_backend ||
140         !qemu_chr_fe_backend_connected(serial_backend)) {
141         return;
142     }
143 
144     c = (unsigned char)env->gr[26];
145     qemu_chr_fe_write(serial_backend, &c, sizeof(c));
146 }
147 #endif
148