1 /*
2 * Copyright (c) 2011 - 2019, Max Filippov, Open Source and Linux Lab.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of the Open Source and Linux Lab nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "qemu/osdep.h"
29 #include "qemu/log.h"
30 #include "cpu.h"
31 #include "exec/helper-proto.h"
32 #include "qemu/host-utils.h"
33 #include "exec/exec-all.h"
34
copy_window_from_phys(CPUXtensaState * env,uint32_t window,uint32_t phys,uint32_t n)35 static void copy_window_from_phys(CPUXtensaState *env,
36 uint32_t window, uint32_t phys, uint32_t n)
37 {
38 assert(phys < env->config->nareg);
39 if (phys + n <= env->config->nareg) {
40 memcpy(env->regs + window, env->phys_regs + phys,
41 n * sizeof(uint32_t));
42 } else {
43 uint32_t n1 = env->config->nareg - phys;
44 memcpy(env->regs + window, env->phys_regs + phys,
45 n1 * sizeof(uint32_t));
46 memcpy(env->regs + window + n1, env->phys_regs,
47 (n - n1) * sizeof(uint32_t));
48 }
49 }
50
copy_phys_from_window(CPUXtensaState * env,uint32_t phys,uint32_t window,uint32_t n)51 static void copy_phys_from_window(CPUXtensaState *env,
52 uint32_t phys, uint32_t window, uint32_t n)
53 {
54 assert(phys < env->config->nareg);
55 if (phys + n <= env->config->nareg) {
56 memcpy(env->phys_regs + phys, env->regs + window,
57 n * sizeof(uint32_t));
58 } else {
59 uint32_t n1 = env->config->nareg - phys;
60 memcpy(env->phys_regs + phys, env->regs + window,
61 n1 * sizeof(uint32_t));
62 memcpy(env->phys_regs, env->regs + window + n1,
63 (n - n1) * sizeof(uint32_t));
64 }
65 }
66
windowbase_bound(unsigned a,const CPUXtensaState * env)67 static inline unsigned windowbase_bound(unsigned a, const CPUXtensaState *env)
68 {
69 return a & (env->config->nareg / 4 - 1);
70 }
71
windowstart_bit(unsigned a,const CPUXtensaState * env)72 static inline unsigned windowstart_bit(unsigned a, const CPUXtensaState *env)
73 {
74 return 1 << windowbase_bound(a, env);
75 }
76
xtensa_sync_window_from_phys(CPUXtensaState * env)77 void xtensa_sync_window_from_phys(CPUXtensaState *env)
78 {
79 copy_window_from_phys(env, 0, env->sregs[WINDOW_BASE] * 4, 16);
80 }
81
xtensa_sync_phys_from_window(CPUXtensaState * env)82 void xtensa_sync_phys_from_window(CPUXtensaState *env)
83 {
84 copy_phys_from_window(env, env->sregs[WINDOW_BASE] * 4, 0, 16);
85 }
86
xtensa_rotate_window_abs(CPUXtensaState * env,uint32_t position)87 static void xtensa_rotate_window_abs(CPUXtensaState *env, uint32_t position)
88 {
89 xtensa_sync_phys_from_window(env);
90 env->sregs[WINDOW_BASE] = windowbase_bound(position, env);
91 xtensa_sync_window_from_phys(env);
92 }
93
xtensa_rotate_window(CPUXtensaState * env,uint32_t delta)94 void xtensa_rotate_window(CPUXtensaState *env, uint32_t delta)
95 {
96 xtensa_rotate_window_abs(env, env->sregs[WINDOW_BASE] + delta);
97 }
98
HELPER(sync_windowbase)99 void HELPER(sync_windowbase)(CPUXtensaState *env)
100 {
101 xtensa_rotate_window_abs(env, env->windowbase_next);
102 }
103
HELPER(entry)104 void HELPER(entry)(CPUXtensaState *env, uint32_t pc, uint32_t s, uint32_t imm)
105 {
106 int callinc = (env->sregs[PS] & PS_CALLINC) >> PS_CALLINC_SHIFT;
107
108 env->regs[(callinc << 2) | (s & 3)] = env->regs[s] - imm;
109 env->windowbase_next = env->sregs[WINDOW_BASE] + callinc;
110 env->sregs[WINDOW_START] |= windowstart_bit(env->windowbase_next, env);
111 }
112
HELPER(window_check)113 void HELPER(window_check)(CPUXtensaState *env, uint32_t pc, uint32_t w)
114 {
115 uint32_t windowbase = windowbase_bound(env->sregs[WINDOW_BASE], env);
116 uint32_t windowstart = xtensa_replicate_windowstart(env) >>
117 (env->sregs[WINDOW_BASE] + 1);
118 uint32_t n = ctz32(windowstart) + 1;
119
120 assert(n <= w);
121
122 xtensa_rotate_window(env, n);
123 env->sregs[PS] = (env->sregs[PS] & ~PS_OWB) |
124 (windowbase << PS_OWB_SHIFT) | PS_EXCM;
125 env->sregs[EPC1] = env->pc = pc;
126
127 switch (ctz32(windowstart >> n)) {
128 case 0:
129 HELPER(exception)(env, EXC_WINDOW_OVERFLOW4);
130 break;
131 case 1:
132 HELPER(exception)(env, EXC_WINDOW_OVERFLOW8);
133 break;
134 default:
135 HELPER(exception)(env, EXC_WINDOW_OVERFLOW12);
136 break;
137 }
138 }
139
HELPER(test_ill_retw)140 void HELPER(test_ill_retw)(CPUXtensaState *env, uint32_t pc)
141 {
142 int n = (env->regs[0] >> 30) & 0x3;
143 int m = 0;
144 uint32_t windowbase = windowbase_bound(env->sregs[WINDOW_BASE], env);
145 uint32_t windowstart = env->sregs[WINDOW_START];
146
147 if (windowstart & windowstart_bit(windowbase - 1, env)) {
148 m = 1;
149 } else if (windowstart & windowstart_bit(windowbase - 2, env)) {
150 m = 2;
151 } else if (windowstart & windowstart_bit(windowbase - 3, env)) {
152 m = 3;
153 }
154
155 if (n == 0 || (m != 0 && m != n)) {
156 qemu_log_mask(LOG_GUEST_ERROR, "Illegal retw instruction(pc = %08x), "
157 "PS = %08x, m = %d, n = %d\n",
158 pc, env->sregs[PS], m, n);
159 HELPER(exception_cause)(env, pc, ILLEGAL_INSTRUCTION_CAUSE);
160 }
161 }
162
HELPER(test_underflow_retw)163 void HELPER(test_underflow_retw)(CPUXtensaState *env, uint32_t pc)
164 {
165 int n = (env->regs[0] >> 30) & 0x3;
166
167 if (!(env->sregs[WINDOW_START] &
168 windowstart_bit(env->sregs[WINDOW_BASE] - n, env))) {
169 uint32_t windowbase = windowbase_bound(env->sregs[WINDOW_BASE], env);
170
171 xtensa_rotate_window(env, -n);
172 /* window underflow */
173 env->sregs[PS] = (env->sregs[PS] & ~PS_OWB) |
174 (windowbase << PS_OWB_SHIFT) | PS_EXCM;
175 env->sregs[EPC1] = env->pc = pc;
176
177 if (n == 1) {
178 HELPER(exception)(env, EXC_WINDOW_UNDERFLOW4);
179 } else if (n == 2) {
180 HELPER(exception)(env, EXC_WINDOW_UNDERFLOW8);
181 } else if (n == 3) {
182 HELPER(exception)(env, EXC_WINDOW_UNDERFLOW12);
183 }
184 }
185 }
186
HELPER(retw)187 void HELPER(retw)(CPUXtensaState *env, uint32_t a0)
188 {
189 int n = (a0 >> 30) & 0x3;
190
191 xtensa_rotate_window(env, -n);
192 }
193
xtensa_restore_owb(CPUXtensaState * env)194 void xtensa_restore_owb(CPUXtensaState *env)
195 {
196 xtensa_rotate_window_abs(env, (env->sregs[PS] & PS_OWB) >> PS_OWB_SHIFT);
197 }
198
HELPER(restore_owb)199 void HELPER(restore_owb)(CPUXtensaState *env)
200 {
201 xtensa_restore_owb(env);
202 }
203
HELPER(movsp)204 void HELPER(movsp)(CPUXtensaState *env, uint32_t pc)
205 {
206 if ((env->sregs[WINDOW_START] &
207 (windowstart_bit(env->sregs[WINDOW_BASE] - 3, env) |
208 windowstart_bit(env->sregs[WINDOW_BASE] - 2, env) |
209 windowstart_bit(env->sregs[WINDOW_BASE] - 1, env))) == 0) {
210 HELPER(exception_cause)(env, pc, ALLOCA_CAUSE);
211 }
212 }
213