xref: /openbmc/qemu/target/hppa/sys_helper.c (revision b2580720)
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 "qemu/log.h"
22 #include "cpu.h"
23 #include "exec/exec-all.h"
24 #include "exec/helper-proto.h"
25 #include "qemu/timer.h"
26 #include "sysemu/runstate.h"
27 #include "sysemu/sysemu.h"
28 #include "chardev/char-fe.h"
29 
30 void HELPER(write_interval_timer)(CPUHPPAState *env, target_ulong val)
31 {
32     HPPACPU *cpu = env_archcpu(env);
33     uint64_t current = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
34     uint64_t timeout;
35 
36     /*
37      * Even in 64-bit mode, the comparator is always 32-bit.  But the
38      * value we expose to the guest is 1/4 of the speed of the clock,
39      * so moosh in 34 bits.
40      */
41     timeout = deposit64(current, 0, 34, (uint64_t)val << 2);
42 
43     /* If the mooshing puts the clock in the past, advance to next round.  */
44     if (timeout < current + 1000) {
45         timeout += 1ULL << 34;
46     }
47 
48     cpu->env.cr[CR_IT] = timeout;
49     timer_mod(cpu->alarm_timer, timeout);
50 }
51 
52 void HELPER(halt)(CPUHPPAState *env)
53 {
54     qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
55     helper_excp(env, EXCP_HLT);
56 }
57 
58 void HELPER(reset)(CPUHPPAState *env)
59 {
60     qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
61     helper_excp(env, EXCP_HLT);
62 }
63 
64 target_ulong HELPER(swap_system_mask)(CPUHPPAState *env, target_ulong nsm)
65 {
66     target_ulong psw = env->psw;
67     /*
68      * Setting the PSW Q bit to 1, if it was not already 1, is an
69      * undefined operation.
70      *
71      * However, HP-UX 10.20 does this with the SSM instruction.
72      * Tested this on HP9000/712 and HP9000/785/C3750 and both
73      * machines set the Q bit from 0 to 1 without an exception,
74      * so let this go without comment.
75      */
76     env->psw = (psw & ~PSW_SM) | (nsm & PSW_SM);
77     return psw & PSW_SM;
78 }
79 
80 void HELPER(rfi)(CPUHPPAState *env)
81 {
82     uint64_t mask;
83 
84     cpu_hppa_put_psw(env, env->cr[CR_IPSW]);
85 
86     /*
87      * For pa2.0, IIASQ is the top bits of the virtual address.
88      * To recreate the space identifier, remove the offset bits.
89      * For pa1.x, the mask reduces to no change to space.
90      */
91     mask = gva_offset_mask(env->psw);
92 
93     env->iaoq_f = env->cr[CR_IIAOQ];
94     env->iaoq_b = env->cr_back[1];
95     env->iasq_f = (env->cr[CR_IIASQ] << 32) & ~(env->iaoq_f & mask);
96     env->iasq_b = (env->cr_back[0] << 32) & ~(env->iaoq_b & mask);
97 
98     if (qemu_loglevel_mask(CPU_LOG_INT)) {
99         FILE *logfile = qemu_log_trylock();
100         if (logfile) {
101             CPUState *cs = env_cpu(env);
102 
103             fprintf(logfile, "RFI: cpu %d\n", cs->cpu_index);
104             hppa_cpu_dump_state(cs, logfile, 0);
105             qemu_log_unlock(logfile);
106         }
107     }
108 }
109 
110 static void getshadowregs(CPUHPPAState *env)
111 {
112     env->gr[1] = env->shadow[0];
113     env->gr[8] = env->shadow[1];
114     env->gr[9] = env->shadow[2];
115     env->gr[16] = env->shadow[3];
116     env->gr[17] = env->shadow[4];
117     env->gr[24] = env->shadow[5];
118     env->gr[25] = env->shadow[6];
119 }
120 
121 void HELPER(rfi_r)(CPUHPPAState *env)
122 {
123     getshadowregs(env);
124     helper_rfi(env);
125 }
126 
127 #ifndef CONFIG_USER_ONLY
128 /*
129  * diag_console_output() is a helper function used during the initial bootup
130  * process of the SeaBIOS-hppa firmware.  During the bootup phase, addresses of
131  * serial ports on e.g. PCI busses are unknown and most other devices haven't
132  * been initialized and configured yet.  With help of a simple "diag" assembler
133  * instruction and an ASCII character code in register %r26 firmware can easily
134  * print debug output without any dependencies to the first serial port and use
135  * that as serial console.
136  */
137 void HELPER(diag_console_output)(CPUHPPAState *env)
138 {
139     CharBackend *serial_backend;
140     Chardev *serial_port;
141     unsigned char c;
142 
143     /* find first serial port */
144     serial_port = serial_hd(0);
145     if (!serial_port) {
146         return;
147     }
148 
149     /* get serial_backend for the serial port */
150     serial_backend = serial_port->be;
151     if (!serial_backend ||
152         !qemu_chr_fe_backend_connected(serial_backend)) {
153         return;
154     }
155 
156     c = (unsigned char)env->gr[26];
157     qemu_chr_fe_write(serial_backend, &c, sizeof(c));
158 }
159 #endif
160