jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
target/xtensa: only rotate window in the retw helper
Move return address calculation and WINDOW_START adjustment out of the
retw helper to simplify logic a bit and avoid using registers directly.
Pass a0 as a parameter to the helper.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+10
-9
+1
-1
target/xtensa/helper.h
+1
-1
target/xtensa/helper.h
···
7
7
DEF_HELPER_4(entry, void, env, i32, i32, i32)
8
8
DEF_HELPER_2(test_ill_retw, void, env, i32)
9
9
DEF_HELPER_2(test_underflow_retw, void, env, i32)
10
-
DEF_HELPER_2(retw, i32, env, i32)
10
+
DEF_HELPER_2(retw, void, env, i32)
11
11
DEF_HELPER_3(window_check, noreturn, env, i32, i32)
12
12
DEF_HELPER_1(restore_owb, void, env)
13
13
DEF_HELPER_2(movsp, void, env, i32)
+7
-2
target/xtensa/translate.c
+7
-2
target/xtensa/translate.c
···
2227
2227
static void translate_retw(DisasContext *dc, const uint32_t arg[],
2228
2228
const uint32_t par[])
2229
2229
{
2230
-
TCGv_i32 tmp = tcg_const_i32(dc->pc);
2231
-
gen_helper_retw(tmp, cpu_env, tmp);
2230
+
TCGv_i32 tmp = tcg_const_i32(1);
2231
+
tcg_gen_shl_i32(tmp, tmp, cpu_SR[WINDOW_BASE]);
2232
+
tcg_gen_andc_i32(cpu_SR[WINDOW_START],
2233
+
cpu_SR[WINDOW_START], tmp);
2234
+
tcg_gen_movi_i32(tmp, dc->pc);
2235
+
tcg_gen_deposit_i32(tmp, tmp, cpu_R[0], 0, 30);
2236
+
gen_helper_retw(cpu_env, cpu_R[0]);
2232
2237
gen_jump(dc, tmp);
2233
2238
tcg_temp_free(tmp);
2234
2239
}
+2
-6
target/xtensa/win_helper.c
+2
-6
target/xtensa/win_helper.c
···
184
184
}
185
185
}
186
186
187
-
uint32_t HELPER(retw)(CPUXtensaState *env, uint32_t pc)
187
+
void HELPER(retw)(CPUXtensaState *env, uint32_t a0)
188
188
{
189
-
int n = (env->regs[0] >> 30) & 0x3;
190
-
uint32_t windowbase = windowbase_bound(env->sregs[WINDOW_BASE], env);
191
-
uint32_t ret_pc = (pc & 0xc0000000) | (env->regs[0] & 0x3fffffff);
189
+
int n = (a0 >> 30) & 0x3;
192
190
193
191
xtensa_rotate_window(env, -n);
194
-
env->sregs[WINDOW_START] &= ~windowstart_bit(windowbase, env);
195
-
return ret_pc;
196
192
}
197
193
198
194
void xtensa_restore_owb(CPUXtensaState *env)