Commit 0cdb9554 authored by Aurelien Jarno's avatar Aurelien Jarno
Browse files

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: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 05b922dd

target-sh4/translate.c

+3 −11
Original line number Diff line number Diff line
@@ -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;