target-sh4: ignore ocbp and ocbwb instructions
ocbp and ocbwb controls the writeback of a cache line to memory. They
are supposed to do nothing in case of a cache miss. Given QEMU only
partially emulate caches, it is safe to ignore these instructions.
This fixes a kernel oops when trying to access an rtl8139 NIC with
recent versions.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
diff --git a/target-sh4/translate.c b/target-sh4/translate.c
index 2ecb236..aacf96d 100644
--- a/target-sh4/translate.c
+++ b/target-sh4/translate.c
@@ -1652,18 +1652,10 @@
}
return;
case 0x00a3: /* ocbp @Rn */
- {
- TCGv dummy = tcg_temp_new();
- tcg_gen_qemu_ld32s(dummy, REG(B11_8), ctx->memidx);
- tcg_temp_free(dummy);
- }
- return;
case 0x00b3: /* ocbwb @Rn */
- {
- TCGv dummy = tcg_temp_new();
- tcg_gen_qemu_ld32s(dummy, REG(B11_8), ctx->memidx);
- tcg_temp_free(dummy);
- }
+ /* These instructions are supposed to do nothing in case of
+ a cache miss. Given that we only partially emulate caches
+ it is safe to simply ignore them. */
return;
case 0x0083: /* pref @Rn */
return;
