From patchwork Mon Mar 8 12:11:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Cave-Ayland X-Patchwork-Id: 1449002 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DvHPj5hSlz9sW1 for ; Mon, 8 Mar 2021 23:16:25 +1100 (AEDT) Received: from localhost ([::1]:57896 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJEoB-0006Uf-Su for incoming@patchwork.ozlabs.org; Mon, 08 Mar 2021 07:16:23 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:33962) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJEkG-0002zn-1x for qemu-devel@nongnu.org; Mon, 08 Mar 2021 07:12:20 -0500 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:45218 helo=mail.default.ilande.uk0.bigv.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJEkE-0001w0-Hu for qemu-devel@nongnu.org; Mon, 08 Mar 2021 07:12:19 -0500 Received: from host86-148-34-47.range86-148.btcentralplus.com ([86.148.34.47] helo=kentang.home) by mail.default.ilande.uk0.bigv.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lJEk9-0004B0-6h; Mon, 08 Mar 2021 12:12:18 +0000 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, laurent@vivier.eu Date: Mon, 8 Mar 2021 12:11:55 +0000 Message-Id: <20210308121155.2476-4-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210308121155.2476-1-mark.cave-ayland@ilande.co.uk> References: <20210308121155.2476-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 86.148.34.47 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH v2 3/3] target/m68k: add M68K_FEATURE_UNALIGNED_DATA feature X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.uk0.bigv.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.uk0.bigv.io X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" According to the M68040UM Appendix D the requirement for data accesses to be word aligned is only for the 68000, 68008 and 68010 CPUs. Later CPUs from the 68020 onwards will allow unaligned data accesses but at the cost of being less efficient. Add a new M68K_FEATURE_UNALIGNED_DATA feature to specify that data accesses are not required to be word aligned, and don't perform the alignment on the stack pointer when taking an exception if this feature is not selected. This is required because the MacOS DAFB driver attempts to call an A-trap with a byte-aligned stack pointer during initialisation and without this the stack pointer is off by one when the A-trap returns. Signed-off-by: Mark Cave-Ayland Reviewed-by: Laurent Vivier Reviewed-by: Richard Henderson --- target/m68k/cpu.c | 1 + target/m68k/cpu.h | 2 ++ target/m68k/op_helper.c | 5 ++++- 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c index 37d2ed9dc7..a14874b4da 100644 --- a/target/m68k/cpu.c +++ b/target/m68k/cpu.c @@ -161,6 +161,7 @@ static void m68020_cpu_initfn(Object *obj) m68k_set_feature(env, M68K_FEATURE_CAS); m68k_set_feature(env, M68K_FEATURE_CHK2); m68k_set_feature(env, M68K_FEATURE_MSP); + m68k_set_feature(env, M68K_FEATURE_UNALIGNED_DATA); } /* diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h index ce558e9b03..402c86c876 100644 --- a/target/m68k/cpu.h +++ b/target/m68k/cpu.h @@ -527,6 +527,8 @@ enum m68k_features { M68K_FEATURE_MOVEP, /* MOVEC insn. (from 68010) */ M68K_FEATURE_MOVEC, + /* Unaligned data accesses (680[2346]0) */ + M68K_FEATURE_UNALIGNED_DATA, }; static inline int m68k_feature(CPUM68KState *env, int feature) diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c index 59a6448296..3fa7b7e19e 100644 --- a/target/m68k/op_helper.c +++ b/target/m68k/op_helper.c @@ -348,7 +348,10 @@ static void m68k_interrupt_all(CPUM68KState *env, int is_hw) cpu_m68k_set_sr(env, sr); sp = env->aregs[7]; - sp &= ~1; + if (!m68k_feature(env, M68K_FEATURE_UNALIGNED_DATA)) { + sp &= ~1; + } + if (cs->exception_index == EXCP_ACCESS) { if (env->mmu.fault) { cpu_abort(cs, "DOUBLE MMU FAULT\n");