From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4AAFECAAA7 for ; Mon, 29 Aug 2022 18:23:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229488AbiH2SXk (ORCPT ); Mon, 29 Aug 2022 14:23:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229518AbiH2SXh (ORCPT ); Mon, 29 Aug 2022 14:23:37 -0400 Received: from angie.orcam.me.uk (angie.orcam.me.uk [IPv6:2001:4190:8020::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A13B47E32A; Mon, 29 Aug 2022 11:23:35 -0700 (PDT) Received: by angie.orcam.me.uk (Postfix, from userid 500) id 68A6D92009C; Mon, 29 Aug 2022 20:23:32 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 6294B92009B; Mon, 29 Aug 2022 19:23:32 +0100 (BST) Date: Mon, 29 Aug 2022 19:23:32 +0100 (BST) From: "Maciej W. Rozycki" To: Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" cc: x86@kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RESEND^2][PATCH v3] x86/PCI: Add support for the Intel 82378ZB/82379AB (SIO/SIO.A) PIRQ router Message-ID: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The Intel 82378ZB System I/O (SIO) and 82379AB System I/O APIC (SIO.A) ISA bridges implement PCI interrupt steering with a PIRQ router[1][2] that is exactly the same as that of the PIIX and ICH southbridges (or actually the other way round, given that the SIO ASIC was there first). An earlier version of the SIO, the 82378IB[3][4], does not implement PCI interrupt steering however, so we need to exclude it by checking the low nibble of the PCI Revision Identification Register[5][6] for being at least 3. There is a note in the 82379AB specification update[7] saying that the device ID for that chip is 0x7, rather than 0x484 as stated in the datasheet[8]. It looks like a red herring however, for no report has been ever seen with that value quoted and it matches the documented default value of the PCI Command Register, which comes next after the PCI Device Identification Register, so it looks like a copy-&-paste editorial mistake. NB the 82378ZB has been commonly used with smaller DEC Alpha systems with the contents of the Revision Identification Register reported as one of 0x3, 0x43, or 0x84, so the masking of the high nibble seems indeed right by empirical observation. The value in the high nibble might be either random, or depend on the batch, or correspond to some other state such as reset straps. References: [1] "82378 System I/O (SIO)", Intel Corporation, Order Number: 290473-004, December 1994, Section 4.1.26 "PIRQ[3:0]#--PIRQ Route Control Registers" [2] "82378ZB System I/O (SIO) and 82379AB System I/O APIC (SIO.A)", Intel Corporation, Order Number: 290571-001, March 1996, Section 3.1.25. "PIRQ[3:0]#--PIRQ Route Control Registers", p. 48 [3] "82378IB System I/O (SIO)", Intel Corporation, Order Number: 290473-002, April 1993, Section 5.8.7.7 "Edge and Level Triggered Modes" [4] "82378IB to 82378ZB Errata Fix and Feature Enhancement Conversion FOL933002-01", [5] "82378 System I/O (SIO)", Intel Corporation, Order Number: 290473-004, December 1994, Section 4.1.5. "RID--Revision Identification Register" [6] "82378ZB System I/O (SIO) and 82379AB System I/O APIC (SIO.A)", Intel Corporation, Order Number: 290571-001, March 1996, Section 3.1.5. "RID--Revision Identification Register", p. 34 [7] "Intel 82379AB (SIO.A) System I/O Component Specification Update", Intel Corporation, Order Number: 297734-001, May, 1996, "Component Identification via Programming Interface", p. 5 [8] "82378ZB System I/O (SIO) and 82379AB System I/O APIC (SIO.A)", Intel Corporation, Order Number: 290571-001, March 1996, Section 3.1.2. "DID--Device Identification Register", p. 33 Signed-off-by: Maciej W. Rozycki --- Hi, This patch was dropped from x86/irq due to a bug in a follow-up patch and when resent it was not re-picked up along with the other patches for some reason, so resending verbatim again after another re-verification, against 6.0-rc2 as at yesterday (just before Linus's version bump). Please apply. Maciej Changes from v2: - Regenerate for a merge conflict. Changes from v1: - Add [PATCH] annotation (umm...). - Fix RID values listed to include 0x84 rather than 0x83 (braino). --- arch/x86/pci/irq.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) linux-x86-pirq-router-sio.diff Index: linux-macro/arch/x86/pci/irq.c =================================================================== --- linux-macro.orig/arch/x86/pci/irq.c +++ linux-macro/arch/x86/pci/irq.c @@ -974,11 +974,18 @@ static __init int intel_router_probe(str return 0; switch (device) { + u8 rid; case PCI_DEVICE_ID_INTEL_82375: r->name = "PCEB/ESC"; r->get = pirq_esc_get; r->set = pirq_esc_set; return 1; + case PCI_DEVICE_ID_INTEL_82378: + pci_read_config_byte(router, PCI_REVISION_ID, &rid); + /* Tell 82378IB (rev < 3) and 82378ZB/82379AB apart. */ + if ((rid & 0xfu) < 3) + break; + fallthrough; case PCI_DEVICE_ID_INTEL_82371FB_0: case PCI_DEVICE_ID_INTEL_82371SB_0: case PCI_DEVICE_ID_INTEL_82371AB_0: @@ -1020,7 +1027,7 @@ static __init int intel_router_probe(str case PCI_DEVICE_ID_INTEL_ICH10_3: case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_0: case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_1: - r->name = "PIIX/ICH"; + r->name = "SIO/PIIX/ICH"; r->get = pirq_piix_get; r->set = pirq_piix_set; return 1; @@ -1039,7 +1046,7 @@ static __init int intel_router_probe(str device <= PCI_DEVICE_ID_INTEL_DH89XXCC_LPC_MAX) || (device >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN && device <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX)) { - r->name = "PIIX/ICH"; + r->name = "SIO/PIIX/ICH"; r->get = pirq_piix_get; r->set = pirq_piix_set; return 1;