xref: /openbmc/qemu/target/hppa/op_helper.c (revision 36df75a0)
1 /*
2  * Helpers for HPPA 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 "exec/cpu_ldst.h"
26 #include "qemu/timer.h"
27 #include "trace.h"
28 
29 G_NORETURN void HELPER(excp)(CPUHPPAState *env, int excp)
30 {
31     CPUState *cs = env_cpu(env);
32 
33     cs->exception_index = excp;
34     cpu_loop_exit(cs);
35 }
36 
37 G_NORETURN void hppa_dynamic_excp(CPUHPPAState *env, int excp, uintptr_t ra)
38 {
39     CPUState *cs = env_cpu(env);
40 
41     cs->exception_index = excp;
42     cpu_loop_exit_restore(cs, ra);
43 }
44 
45 void HELPER(tsv)(CPUHPPAState *env, target_ureg cond)
46 {
47     if (unlikely((target_sreg)cond < 0)) {
48         hppa_dynamic_excp(env, EXCP_OVERFLOW, GETPC());
49     }
50 }
51 
52 void HELPER(tcond)(CPUHPPAState *env, target_ureg cond)
53 {
54     if (unlikely(cond)) {
55         hppa_dynamic_excp(env, EXCP_COND, GETPC());
56     }
57 }
58 
59 static void atomic_store_3(CPUHPPAState *env, target_ulong addr,
60                            uint32_t val, uintptr_t ra)
61 {
62     int mmu_idx = cpu_mmu_index(env, 0);
63     uint32_t old, new, cmp, mask, *haddr;
64     void *vaddr;
65 
66     vaddr = probe_access(env, addr, 3, MMU_DATA_STORE, mmu_idx, ra);
67     if (vaddr == NULL) {
68         cpu_loop_exit_atomic(env_cpu(env), ra);
69     }
70     haddr = (uint32_t *)((uintptr_t)vaddr & -4);
71     mask = addr & 1 ? 0x00ffffffu : 0xffffff00u;
72 
73     old = *haddr;
74     while (1) {
75         new = be32_to_cpu((cpu_to_be32(old) & ~mask) | (val & mask));
76         cmp = qatomic_cmpxchg(haddr, old, new);
77         if (cmp == old) {
78             return;
79         }
80         old = cmp;
81     }
82 }
83 
84 static void do_stby_b(CPUHPPAState *env, target_ulong addr, target_ureg val,
85                       bool parallel, uintptr_t ra)
86 {
87     switch (addr & 3) {
88     case 3:
89         cpu_stb_data_ra(env, addr, val, ra);
90         break;
91     case 2:
92         cpu_stw_data_ra(env, addr, val, ra);
93         break;
94     case 1:
95         /* The 3 byte store must appear atomic.  */
96         if (parallel) {
97             atomic_store_3(env, addr, val, ra);
98         } else {
99             cpu_stb_data_ra(env, addr, val >> 16, ra);
100             cpu_stw_data_ra(env, addr + 1, val, ra);
101         }
102         break;
103     default:
104         cpu_stl_data_ra(env, addr, val, ra);
105         break;
106     }
107 }
108 
109 void HELPER(stby_b)(CPUHPPAState *env, target_ulong addr, target_ureg val)
110 {
111     do_stby_b(env, addr, val, false, GETPC());
112 }
113 
114 void HELPER(stby_b_parallel)(CPUHPPAState *env, target_ulong addr,
115                              target_ureg val)
116 {
117     do_stby_b(env, addr, val, true, GETPC());
118 }
119 
120 static void do_stby_e(CPUHPPAState *env, target_ulong addr, target_ureg val,
121                       bool parallel, uintptr_t ra)
122 {
123     switch (addr & 3) {
124     case 3:
125         /* The 3 byte store must appear atomic.  */
126         if (parallel) {
127             atomic_store_3(env, addr - 3, val, ra);
128         } else {
129             cpu_stw_data_ra(env, addr - 3, val >> 16, ra);
130             cpu_stb_data_ra(env, addr - 1, val >> 8, ra);
131         }
132         break;
133     case 2:
134         cpu_stw_data_ra(env, addr - 2, val >> 16, ra);
135         break;
136     case 1:
137         cpu_stb_data_ra(env, addr - 1, val >> 24, ra);
138         break;
139     default:
140         /* Nothing is stored, but protection is checked and the
141            cacheline is marked dirty.  */
142         probe_write(env, addr, 0, cpu_mmu_index(env, 0), ra);
143         break;
144     }
145 }
146 
147 void HELPER(stby_e)(CPUHPPAState *env, target_ulong addr, target_ureg val)
148 {
149     do_stby_e(env, addr, val, false, GETPC());
150 }
151 
152 void HELPER(stby_e_parallel)(CPUHPPAState *env, target_ulong addr,
153                              target_ureg val)
154 {
155     do_stby_e(env, addr, val, true, GETPC());
156 }
157 
158 void HELPER(ldc_check)(target_ulong addr)
159 {
160     if (unlikely(addr & 0xf)) {
161         qemu_log_mask(LOG_GUEST_ERROR,
162                       "Undefined ldc to unaligned address mod 16: "
163                       TARGET_FMT_lx "\n", addr);
164     }
165 }
166 
167 target_ureg HELPER(probe)(CPUHPPAState *env, target_ulong addr,
168                           uint32_t level, uint32_t want)
169 {
170 #ifdef CONFIG_USER_ONLY
171     return page_check_range(addr, 1, want);
172 #else
173     int prot, excp;
174     hwaddr phys;
175 
176     trace_hppa_tlb_probe(addr, level, want);
177     /* Fail if the requested privilege level is higher than current.  */
178     if (level < (env->iaoq_f & 3)) {
179         return 0;
180     }
181 
182     excp = hppa_get_physical_address(env, addr, level, 0, &phys, &prot);
183     if (excp >= 0) {
184         if (env->psw & PSW_Q) {
185             /* ??? Needs tweaking for hppa64.  */
186             env->cr[CR_IOR] = addr;
187             env->cr[CR_ISR] = addr >> 32;
188         }
189         if (excp == EXCP_DTLB_MISS) {
190             excp = EXCP_NA_DTLB_MISS;
191         }
192         hppa_dynamic_excp(env, excp, GETPC());
193     }
194     return (want & prot) != 0;
195 #endif
196 }
197 
198 target_ureg HELPER(read_interval_timer)(void)
199 {
200 #ifdef CONFIG_USER_ONLY
201     /* In user-mode, QEMU_CLOCK_VIRTUAL doesn't exist.
202        Just pass through the host cpu clock ticks.  */
203     return cpu_get_host_ticks();
204 #else
205     /* In system mode we have access to a decent high-resolution clock.
206        In order to make OS-level time accounting work with the cr16,
207        present it with a well-timed clock fixed at 250MHz.  */
208     return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) >> 2;
209 #endif
210 }
211