From nobody Mon Feb 9 23:18:53 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1615148858; cv=none; d=zohomail.com; s=zohoarc; b=ckk0BB0WlcEPiGZkCKVWWohsPVzkoRYK9IEKHm4EOSW/qenvShQeIY971iW69nJPDA+94+vhq6J3gITT+KvsCXlonTdeGX4iHfzJsvTuQeN9MCUlbyZ4vFZQVjPVK1AsXyGXOzd9ioHRYOSEm6jXA4DGyThfx6hZ+Uyi5MOZRlE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1615148858; h=Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=X94fCWW62Anhv8PPDwvY/FpnCRq5nS83FMyL8XYSbEU=; b=V0akUGNqXx9t0SNlhyd8nzMPnhTMOmmb5MGus+fzIKKk7PK8omXF/qd6tq/QaFQC9OEh5a9jYW8Y8fTSXTvgDMBV1YD+u6fsEwUhw2FUiWlniCGDkNlQfAjppHnPiPby3IXUPm913tO5bM3JQPJMph7KKotFpmHuTdPIHMKxuFc= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1615148858708732.4909027557035; Sun, 7 Mar 2021 12:27:38 -0800 (PST) Received: from localhost ([::1]:53234 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJ001-0006ow-3l for importer@patchew.org; Sun, 07 Mar 2021 15:27:37 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56886) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lIzyq-0005WY-Lp for qemu-devel@nongnu.org; Sun, 07 Mar 2021 15:26:24 -0500 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:44128 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 1lIzyp-0006sq-4w for qemu-devel@nongnu.org; Sun, 07 Mar 2021 15:26:24 -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 1lIzyi-0005R9-Nm; Sun, 07 Mar 2021 20:26:22 +0000 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, laurent@vivier.eu Date: Sun, 7 Mar 2021 20:26:06 +0000 Message-Id: <20210307202607.27745-2-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210307202607.27745-1-mark.cave-ayland@ilande.co.uk> References: <20210307202607.27745-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 86.148.34.47 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH 1/2] target/m68k: don't set SSW ATC bit for physical bus errors 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 (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" If a NuBus slot doesn't contain a card, the Quadra hardware generates a phy= sical bus error if the CPU attempts to access the slot address space. Both Linux = and MacOS use a separate bus error handler during NuBus accesses in order to de= tect and recover when addressing empty slots. According to the MC68040 users manual the ATC bit of the SSW is used to distinguish between ATC faults and physical bus errors. MacOS specifically = checks the stack frame generated by a NuBus error and panics if the SSW ATC bit is= set. Update m68k_cpu_transaction_failed() so that the SSW ATC bit is not set if = the memory API returns MEMTX_DECODE_ERROR which will be used to indicate that an access to an empty NuBus slot occurred. Signed-off-by: Mark Cave-Ayland Reviewed-by: Laurent Vivier --- target/m68k/op_helper.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c index 202498deb5..59a6448296 100644 --- a/target/m68k/op_helper.c +++ b/target/m68k/op_helper.c @@ -468,7 +468,17 @@ void m68k_cpu_transaction_failed(CPUState *cs, hwaddr = physaddr, vaddr addr, =20 if (m68k_feature(env, M68K_FEATURE_M68040)) { env->mmu.mmusr =3D 0; - env->mmu.ssw |=3D M68K_ATC_040; + + /* + * According to the MC68040 users manual the ATC bit of the SSW is + * used to distinguish between ATC faults and physical bus errors. + * In the case of a bus error e.g. during nubus read from an empty + * slot this bit should not be set + */ + if (response !=3D MEMTX_DECODE_ERROR) { + env->mmu.ssw |=3D M68K_ATC_040; + } + /* FIXME: manage MMU table access error */ env->mmu.ssw &=3D ~M68K_TM_040; if (env->sr & SR_S) { /* SUPERVISOR */ --=20 2.20.1 From nobody Mon Feb 9 23:18:53 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1615148869; cv=none; d=zohomail.com; s=zohoarc; b=ikykEPwgToCQK2YPMPNjKx8F4UTRccJOjTS8nWD7cDRe+TVoihSHLw3PFMJp6+/ynZ3WKWXEtZx4MUwyxYpiyAdM2zixBRq71Tnf4UKZHLSjHn6JDF+sYUjxwQypREY8TYBfopGEPxAr6Q8+CGDU9T//QhZWTnvHFcbd0k9GEQc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1615148869; h=Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=xvlMdc7+TiXVEX9qWe5hhbbVWDDySCRa7kGZ176FSUY=; b=TcoWaoGF/IV0WWwu8Q1Ag8K6ILG2wX1xNxTRrJFxU346qBEHE/KmD2aeDiaAAdQzlk43dT84ax/CZk+zEXpcg/AzgzvhpVY0unCftDy+K3g/Zcbt+SzTpe/LrcqJ/YvWOmOMxL2uUbuvX91OmA58H39CWnNg95bqqUGtCRv1cyQ= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1615148869718841.4354280110698; Sun, 7 Mar 2021 12:27:49 -0800 (PST) Received: from localhost ([::1]:54190 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJ00C-0007Cy-Jl for importer@patchew.org; Sun, 07 Mar 2021 15:27:48 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56916) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lIzyy-0005ib-2Q for qemu-devel@nongnu.org; Sun, 07 Mar 2021 15:26:32 -0500 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:44132 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 1lIzyw-0006uK-C8 for qemu-devel@nongnu.org; Sun, 07 Mar 2021 15:26:31 -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 1lIzyo-0005R9-WE; Sun, 07 Mar 2021 20:26:29 +0000 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, laurent@vivier.eu Date: Sun, 7 Mar 2021 20:26:07 +0000 Message-Id: <20210307202607.27745-3-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210307202607.27745-1-mark.cave-ayland@ilande.co.uk> References: <20210307202607.27745-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 86.148.34.47 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH 2/2] target/m68k: add M68K_FEATURE_NO_DALIGN 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 (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" 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 t= he 68020 onwards will allow unaligned data accesses but at the cost of being l= ess efficient. Add a new M68K_FEATURE_NO_DALIGN 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 --- target/m68k/cpu.c | 1 + target/m68k/cpu.h | 1 + target/m68k/op_helper.c | 5 ++++- 3 files changed, 6 insertions(+), 1 deletion(-) diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c index 37d2ed9dc7..ea51753eb0 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_NO_DALIGN); } =20 /* diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h index 7c3feeaf8a..1e0876bba8 100644 --- a/target/m68k/cpu.h +++ b/target/m68k/cpu.h @@ -505,6 +505,7 @@ enum m68k_features { M68K_FEATURE_CHK2, /* CHK2 insn. (680[2346]0, and CPU32) */ M68K_FEATURE_MOVEP, /* MOVEP insn. (680[01234]0, and CPU32) */ M68K_FEATURE_MOVEC, /* MOVEC insn. (from 68010) */ + M68K_FEATURE_NO_DALIGN, /* Unaligned data accesses (680[2346]0) */ }; =20 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..71b3df0910 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 =3D env->aregs[7]; =20 - sp &=3D ~1; + if (!m68k_feature(env, M68K_FEATURE_NO_DALIGN)) { + sp &=3D ~1; + } + if (cs->exception_index =3D=3D EXCP_ACCESS) { if (env->mmu.fault) { cpu_abort(cs, "DOUBLE MMU FAULT\n"); --=20 2.20.1