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
copy_window_from_phys(CPUXtensaState * env,uint32_t window,uint32_t phys,uint32_t n)34 static void copy_window_from_phys(CPUXtensaState *env,
35 uint32_t window, uint32_t phys, uint32_t n)
36 {
37 assert(phys < env->config->nareg);
38 if (phys + n <= env->config->nareg) {
39 memcpy(env->regs + window, env->phys_regs + phys,
40 n * sizeof(uint32_t));
41 } else {
42 uint32_t n1 = env->config->nareg - phys;
43 memcpy(env->regs + window, env->phys_regs + phys,
44 n1 * sizeof(uint32_t));
45 memcpy(env->regs + window + n1, env->phys_regs,
46 (n - n1) * sizeof(uint32_t));
47 }
48 }
49
copy_phys_from_window(CPUXtensaState * env,uint32_t phys,uint32_t window,uint32_t n)50 static void copy_phys_from_window(CPUXtensaState *env,
51 uint32_t phys, uint32_t window, uint32_t n)
52 {
53 assert(phys < env->config->nareg);
54 if (phys + n <= env->config->nareg) {
55 memcpy(env->phys_regs + phys, env->regs + window,
56 n * sizeof(uint32_t));
57 } else {
58 uint32_t n1 = env->config->nareg - phys;
59 memcpy(env->phys_regs + phys, env->regs + window,
60 n1 * sizeof(uint32_t));
61 memcpy(env->phys_regs, env->regs + window + n1,
62 (n - n1) * sizeof(uint32_t));
63 }
64 }
65
windowbase_bound(unsigned a,const CPUXtensaState * env)66 static inline unsigned windowbase_bound(unsigned a, const CPUXtensaState *env)
67 {
68 return a & (env->config->nareg / 4 - 1);
69 }
70
windowstart_bit(unsigned a,const CPUXtensaState * env)71 static inline unsigned windowstart_bit(unsigned a, const CPUXtensaState *env)
72 {
73 return 1 << windowbase_bound(a, env);
74 }
75
xtensa_sync_window_from_phys(CPUXtensaState * env)76 void xtensa_sync_window_from_phys(CPUXtensaState *env)
77 {
78 copy_window_from_phys(env, 0, env->sregs[WINDOW_BASE] * 4, 16);
79 }
80
xtensa_sync_phys_from_window(CPUXtensaState * env)81 void xtensa_sync_phys_from_window(CPUXtensaState *env)
82 {
83 copy_phys_from_window(env, env->sregs[WINDOW_BASE] * 4, 0, 16);
84 }
85
xtensa_rotate_window_abs(CPUXtensaState * env,uint32_t position)86 static void xtensa_rotate_window_abs(CPUXtensaState *env, uint32_t position)
87 {
88 xtensa_sync_phys_from_window(env);
89 env->sregs[WINDOW_BASE] = windowbase_bound(position, env);
90 xtensa_sync_window_from_phys(env);
91 }
92
xtensa_rotate_window(CPUXtensaState * env,uint32_t delta)93 void xtensa_rotate_window(CPUXtensaState *env, uint32_t delta)
94 {
95 xtensa_rotate_window_abs(env, env->sregs[WINDOW_BASE] + delta);
96 }
97
HELPER(sync_windowbase)98 void HELPER(sync_windowbase)(CPUXtensaState *env)
99 {
100 xtensa_rotate_window_abs(env, env->windowbase_next);
101 }
102
HELPER(entry)103 void HELPER(entry)(CPUXtensaState *env, uint32_t pc, uint32_t s, uint32_t imm)
104 {
105 int callinc = (env->sregs[PS] & PS_CALLINC) >> PS_CALLINC_SHIFT;
106
107 env->regs[(callinc << 2) | (s & 3)] = env->regs[s] - imm;
108 env->windowbase_next = env->sregs[WINDOW_BASE] + callinc;
109 env->sregs[WINDOW_START] |= windowstart_bit(env->windowbase_next, env);
110 }
111
HELPER(window_check)112 void HELPER(window_check)(CPUXtensaState *env, uint32_t pc, uint32_t w)
113 {
114 uint32_t windowbase = windowbase_bound(env->sregs[WINDOW_BASE], env);
115 uint32_t windowstart = xtensa_replicate_windowstart(env) >>
116 (env->sregs[WINDOW_BASE] + 1);
117 uint32_t n = ctz32(windowstart) + 1;
118
119 assert(n <= w);
120
121 xtensa_rotate_window(env, n);
122 env->sregs[PS] = (env->sregs[PS] & ~PS_OWB) |
123 (windowbase << PS_OWB_SHIFT) | PS_EXCM;
124 env->sregs[EPC1] = env->pc = pc;
125
126 switch (ctz32(windowstart >> n)) {
127 case 0:
128 HELPER(exception)(env, EXC_WINDOW_OVERFLOW4);
129 break;
130 case 1:
131 HELPER(exception)(env, EXC_WINDOW_OVERFLOW8);
132 break;
133 default:
134 HELPER(exception)(env, EXC_WINDOW_OVERFLOW12);
135 break;
136 }
137 }
138
HELPER(test_ill_retw)139 void HELPER(test_ill_retw)(CPUXtensaState *env, uint32_t pc)
140 {
141 int n = (env->regs[0] >> 30) & 0x3;
142 int m = 0;
143 uint32_t windowbase = windowbase_bound(env->sregs[WINDOW_BASE], env);
144 uint32_t windowstart = env->sregs[WINDOW_START];
145
146 if (windowstart & windowstart_bit(windowbase - 1, env)) {
147 m = 1;
148 } else if (windowstart & windowstart_bit(windowbase - 2, env)) {
149 m = 2;
150 } else if (windowstart & windowstart_bit(windowbase - 3, env)) {
151 m = 3;
152 }
153
154 if (n == 0 || (m != 0 && m != n)) {
155 qemu_log_mask(LOG_GUEST_ERROR, "Illegal retw instruction(pc = %08x), "
156 "PS = %08x, m = %d, n = %d\n",
157 pc, env->sregs[PS], m, n);
158 HELPER(exception_cause)(env, pc, ILLEGAL_INSTRUCTION_CAUSE);
159 }
160 }
161
HELPER(test_underflow_retw)162 void HELPER(test_underflow_retw)(CPUXtensaState *env, uint32_t pc)
163 {
164 int n = (env->regs[0] >> 30) & 0x3;
165
166 if (!(env->sregs[WINDOW_START] &
167 windowstart_bit(env->sregs[WINDOW_BASE] - n, env))) {
168 uint32_t windowbase = windowbase_bound(env->sregs[WINDOW_BASE], env);
169
170 xtensa_rotate_window(env, -n);
171 /* window underflow */
172 env->sregs[PS] = (env->sregs[PS] & ~PS_OWB) |
173 (windowbase << PS_OWB_SHIFT) | PS_EXCM;
174 env->sregs[EPC1] = env->pc = pc;
175
176 if (n == 1) {
177 HELPER(exception)(env, EXC_WINDOW_UNDERFLOW4);
178 } else if (n == 2) {
179 HELPER(exception)(env, EXC_WINDOW_UNDERFLOW8);
180 } else if (n == 3) {
181 HELPER(exception)(env, EXC_WINDOW_UNDERFLOW12);
182 }
183 }
184 }
185
HELPER(retw)186 void HELPER(retw)(CPUXtensaState *env, uint32_t a0)
187 {
188 int n = (a0 >> 30) & 0x3;
189
190 xtensa_rotate_window(env, -n);
191 }
192
xtensa_restore_owb(CPUXtensaState * env)193 void xtensa_restore_owb(CPUXtensaState *env)
194 {
195 xtensa_rotate_window_abs(env, (env->sregs[PS] & PS_OWB) >> PS_OWB_SHIFT);
196 }
197
HELPER(restore_owb)198 void HELPER(restore_owb)(CPUXtensaState *env)
199 {
200 xtensa_restore_owb(env);
201 }
202
HELPER(movsp)203 void HELPER(movsp)(CPUXtensaState *env, uint32_t pc)
204 {
205 if ((env->sregs[WINDOW_START] &
206 (windowstart_bit(env->sregs[WINDOW_BASE] - 3, env) |
207 windowstart_bit(env->sregs[WINDOW_BASE] - 2, env) |
208 windowstart_bit(env->sregs[WINDOW_BASE] - 1, env))) == 0) {
209 HELPER(exception_cause)(env, pc, ALLOCA_CAUSE);
210 }
211 }
212