qemu/0019-target-sh4-ignore-ocbp...

48 lines
1.5 KiB
Diff

From 37769d27270eff15d878a1c7df23407fc5f09b7f Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Sat, 7 Jan 2012 15:20:12 +0100
Subject: [PATCH 19/25] 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>
(cherry picked from commit 0cdb95549fedc73e13c147ab9dcabcc303426a07)
---
target-sh4/translate.c | 14 +++-----------
1 files changed, 3 insertions(+), 11 deletions(-)
diff --git a/target-sh4/translate.c b/target-sh4/translate.c
index bad3577..e04a6e0 100644
--- a/target-sh4/translate.c
+++ b/target-sh4/translate.c
@@ -1652,18 +1652,10 @@ static void _decode_opc(DisasContext * ctx)
}
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;
--
1.7.7.5