xref: /openbmc/qemu/target/mips/sysemu/cp0.c (revision ffe98631)
1 /*
2  * QEMU MIPS CPU
3  *
4  * Copyright (c) 2012 SUSE LINUX Products GmbH
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
18  * <http://www.gnu.org/licenses/lgpl-2.1.html>
19  */
20 
21 #include "qemu/osdep.h"
22 #include "cpu.h"
23 #include "internal.h"
24 #include "exec/exec-all.h"
25 
26 /* Called for updates to CP0_Status.  */
27 void sync_c0_status(CPUMIPSState *env, CPUMIPSState *cpu, int tc)
28 {
29     int32_t tcstatus, *tcst;
30     uint32_t v = cpu->CP0_Status;
31     uint32_t cu, mx, asid, ksu;
32     uint32_t mask = ((1 << CP0TCSt_TCU3)
33                        | (1 << CP0TCSt_TCU2)
34                        | (1 << CP0TCSt_TCU1)
35                        | (1 << CP0TCSt_TCU0)
36                        | (1 << CP0TCSt_TMX)
37                        | (3 << CP0TCSt_TKSU)
38                        | (0xff << CP0TCSt_TASID));
39 
40     cu = (v >> CP0St_CU0) & 0xf;
41     mx = (v >> CP0St_MX) & 0x1;
42     ksu = (v >> CP0St_KSU) & 0x3;
43     asid = env->CP0_EntryHi & env->CP0_EntryHi_ASID_mask;
44 
45     tcstatus = cu << CP0TCSt_TCU0;
46     tcstatus |= mx << CP0TCSt_TMX;
47     tcstatus |= ksu << CP0TCSt_TKSU;
48     tcstatus |= asid;
49 
50     if (tc == cpu->current_tc) {
51         tcst = &cpu->active_tc.CP0_TCStatus;
52     } else {
53         tcst = &cpu->tcs[tc].CP0_TCStatus;
54     }
55 
56     *tcst &= ~mask;
57     *tcst |= tcstatus;
58     compute_hflags(cpu);
59 }
60 
61 void cpu_mips_store_status(CPUMIPSState *env, target_ulong val)
62 {
63     uint32_t mask = env->CP0_Status_rw_bitmask;
64     target_ulong old = env->CP0_Status;
65 
66     if (env->insn_flags & ISA_MIPS_R6) {
67         bool has_supervisor = extract32(mask, CP0St_KSU, 2) == 0x3;
68 #if defined(TARGET_MIPS64)
69         uint32_t ksux = (1 << CP0St_KX) & val;
70         ksux |= (ksux >> 1) & val; /* KX = 0 forces SX to be 0 */
71         ksux |= (ksux >> 1) & val; /* SX = 0 forces UX to be 0 */
72         val = (val & ~(7 << CP0St_UX)) | ksux;
73 #endif
74         if (has_supervisor && extract32(val, CP0St_KSU, 2) == 0x3) {
75             mask &= ~(3 << CP0St_KSU);
76         }
77         mask &= ~(((1 << CP0St_SR) | (1 << CP0St_NMI)) & val);
78     }
79 
80     env->CP0_Status = (old & ~mask) | (val & mask);
81 #if defined(TARGET_MIPS64)
82     if ((env->CP0_Status ^ old) & (old & (7 << CP0St_UX))) {
83         /* Access to at least one of the 64-bit segments has been disabled */
84         tlb_flush(env_cpu(env));
85     }
86 #endif
87     if (ase_mt_available(env)) {
88         sync_c0_status(env, env, env->current_tc);
89     } else {
90         compute_hflags(env);
91     }
92 }
93 
94 void cpu_mips_store_cause(CPUMIPSState *env, target_ulong val)
95 {
96     uint32_t mask = 0x00C00300;
97     uint32_t old = env->CP0_Cause;
98     int i;
99 
100     if (env->insn_flags & ISA_MIPS_R2) {
101         mask |= 1 << CP0Ca_DC;
102     }
103     if (env->insn_flags & ISA_MIPS_R6) {
104         mask &= ~((1 << CP0Ca_WP) & val);
105     }
106 
107     env->CP0_Cause = (env->CP0_Cause & ~mask) | (val & mask);
108 
109     if ((old ^ env->CP0_Cause) & (1 << CP0Ca_DC)) {
110         if (env->CP0_Cause & (1 << CP0Ca_DC)) {
111             cpu_mips_stop_count(env);
112         } else {
113             cpu_mips_start_count(env);
114         }
115     }
116 
117     /* Set/reset software interrupts */
118     for (i = 0 ; i < 2 ; i++) {
119         if ((old ^ env->CP0_Cause) & (1 << (CP0Ca_IP + i))) {
120             cpu_mips_soft_irq(env, i, env->CP0_Cause & (1 << (CP0Ca_IP + i)));
121         }
122     }
123 }
124