From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB8944A8FF5 for ; Wed, 2 Sep 2026 15:34:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788363279; cv=none; b=lsTH4/O38JQkbkTRJz89HiAWy0YzLh92KUru/Wu9C8Ga/kn018xh8eWvJmR+wERyVvb9vGVuLHfYEVM3r7mBFvIgsdh8ADPLeS/LaIVOVsJQSCkk6JihNZQPrPGb9UwlThkhV7Rtz5Rp3P/viNTROLuF8at5qq+zU637SLJJUuU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788363279; c=relaxed/simple; bh=ioFSQLuHXnoqonY/mNTRe2D7gsjT6CZyV92GMFjQ8ys=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aXmCrk5Yt/pyldFvRYFYUrckniXIH508PbTKvk59VeacF/wcF/6Qp39umOMDwtWZXO2+WmpwDxI7V2BoHqw3AM9zn/x8Gk+zMZI/JmYvo3W/AoEsI5Lry5vwO3huXX2yUlYV8vmnXdWSyX7ZcEz9yyGH5KxX0zZyx0lrNXdOqZQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=MFbe8eiw; arc=none smtp.client-ip=192.198.163.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="MFbe8eiw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1788363274; x=1819899274; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=ioFSQLuHXnoqonY/mNTRe2D7gsjT6CZyV92GMFjQ8ys=; b=MFbe8eiwPvil/W/I8v8v9D7OdmOm9wUONXaQ+Gp39vDyzcb0mfHQZpCw 4L036NKYq/ddcTEyo8MtCkgR+vNUYHcSsEo6kCr+K3kMBYLMaFUB50Ubh YkuCc3RDsjSwiTh9qP37Q9z2PBsV0nn0iDaSp06Qp+x+dDpuBP8JnSjb7 hiH18RDhVjl/SIsUK5uuN1sB2JnpgjvrEilzny5cbPHLqLY4zUz5pMg6G PJO4crwk/bu9YzWyXyPWFJznX6400MJtxEST00wmVTYE38OIcnXO0bK9W sOtINMqf3ZQBLiu4TwVdkCsXMuCGHwRm0InVJ1PEr1X1njP3ZBEhcdp5m Q==; X-CSE-ConnectionGUID: /78ne3tmQ365trROWfCb3g== X-CSE-MsgGUID: wj9LjQuhSYmF2CG6nZw/Xw== X-IronPort-AV: E=McAfee;i="6800,10657,11894"; a="92646699" X-IronPort-AV: E=Sophos;i="6.25,258,1779174000"; d="scan'208";a="92646699" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Sep 2026 08:34:33 -0700 X-CSE-ConnectionGUID: rGXoxqq5RO+TpuZLpB+0Dw== X-CSE-MsgGUID: wYY/nW2dSBmO17yuSXxhAQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,258,1779174000"; d="scan'208";a="271406892" Received: from ubuntu.igk.intel.com ([10.102.114.174]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Sep 2026 08:34:31 -0700 From: Szymon Durawa To: helgaas@kernel.org, nirmal.patel@linux.intel.com, szymon.durawa@linux.intel.com, djbw@kernel.org, linux-pci@vger.kernel.org, lukas@wunner.de Subject: [PATCH v7 8/8] PCI: vmd: Add workaround for bus number hardwired to fixed non-zero value Date: Wed, 2 Sep 2026 17:58:44 +0000 Message-ID: <20260902175846.3497854-9-szymon.durawa@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260902175846.3497854-1-szymon.durawa@linux.intel.com> References: <20260902175846.3497854-1-szymon.durawa@linux.intel.com> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The VMD BUS1 root bus number is fixed in hardware to 0x80. It marks bridge invalid configuration when detecting a non-zero (0x80) the VMD BUS1 root bus number. Thus root bus number is deconfigured in the first pass of pci_scan_bridge() to be re-assigned to 0x0 in the second pass. As a result no subordinate bus number behind VMD BUS1 is found. To avoid bus number reconfiguration, BUS1 number has to be the same as BUS1 primary number. Log snippet without workaround: [ 3.752507] vmd 0000:00:0e.0: PCI host bridge to bus 10000:e1 [ 3.752510] pci_bus 10000:e1: busn_res: can not insert [bus e1-ff] under domain [bus 00-ff] (conflicts with (null) [bus e0-f0]) [ 3.752515] pci_bus 10000:e1: root bus resource [bus f1-ff] [ 3.752517] pci_bus 10000:e1: root bus resource [mem 0x8c800000-0x8cffffff] [ 3.752519] pci_bus 10000:e1: root bus resource [mem 0x701b802000-0x701bffffff 64bit] [ 3.752523] pci_bus 10000:e1: scanning bus [ 3.752732] pci (null): Looking for ACPI companion (address 0x80e0ffff) [ 3.752745] pci 10000:e1:1c.0: [8086:7f38] type 01 class 0x060400 PCIe Root Port [ 3.752779] pci 10000:e1:1c.0: PCI bridge to [bus f1] [ 3.752861] pci 10000:e1:1c.0: PME# supported from D0 D3hot D3cold [ 3.752864] pci 10000:e1:1c.0: PME# disabled [ 3.752909] pci 10000:e1:1c.0: PTM enabled (root), 4ns granularity [ 3.752981] pci 10000:e1:1c.0: vgaarb: pci_notify [ 3.752987] pci_bus 10000:e1: fixups for bus [ 3.752992] pci 10000:e1:1c.0: scanning [bus f1-f1] behind bridge, pass 0 [ 3.752993] pci 10000:e1:1c.0: primary 80, bus->number e1. [ 3.752994] pci 10000:e1:1c.0: bridge configuration invalid ([bus f1-f1]), reconfiguring [ 3.753003] pci 10000:e1:1c.0: scanning [bus 00-00] behind bridge, pass 1 [ 3.753004] pci 10000:e1:1c.0: primary 00, bus->number e1. Suggested-by: Nirmal Patel Signed-off-by: Szymon Durawa --- drivers/pci/controller/vmd.c | 66 ++++++++++++++++++++++++++++++++---- 1 file changed, 60 insertions(+), 6 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 7e76ef3d7ec8..f4c6a16e8473 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -467,10 +467,23 @@ static unsigned int vmd_bus_to_ecam(struct vmd_dev *vmd, unsigned int busnr) static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus, unsigned int devfn, int reg, int len) { + unsigned char bus_number; unsigned int busnr_ecam; u32 offset; - busnr_ecam = vmd_bus_to_ecam(vmd, bus->number); + /* + * Remap ONLY the virtual BUS1 root bus number (0x80) to its physical + * CFGBAR start aperture (0xE1). Downstream subordinate buses behind + * the root port are assigned physical numbers (0xF1..0xFF per + * VMD_BUSRANGE1) and must NOT be remapped, otherwise child endpoint + * accesses would target the root port rather than their own ECAM space. + */ + if (vmd->bus1_rootbus && bus->number == VMD_PRIMARY_BUS1) + bus_number = vmd->busn_start[VMD_BUS_1]; + else + bus_number = bus->number; + + busnr_ecam = vmd_bus_to_ecam(vmd, bus_number); offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg); if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR])) @@ -550,18 +563,39 @@ static struct pci_ops vmd_ops = { static struct acpi_device *vmd_acpi_find_companion(struct pci_dev *pci_dev) { struct pci_host_bridge *bridge; - u32 busnr, addr; + struct vmd_dev *vmd; + u32 addr; + int busnr; + u8 pci_bus_number; + u8 bridge_bus_number; if (pci_dev->bus->ops != &vmd_ops) return NULL; + vmd = vmd_from_bus(pci_dev->bus); bridge = pci_find_host_bridge(pci_dev->bus); - busnr = pci_dev->bus->number - bridge->bus->number; + pci_bus_number = pci_dev->bus->number; + bridge_bus_number = bridge->bus->number; + + /* + * BUS1 is registered with logical root number 0x80. For ACPI companion + * matching, map only the logical root bus (0x80) to the physical + * BUS1 start base (0xE1). Downstream child buses (0xF1..0xFF) already + * reflect their physical bus numbers and must remain untranslated to + * produce the correct relative depth against bridge_bus_number. + */ + if (vmd->bus1_rootbus && bridge->bus == vmd->bus[VMD_BUS_1]) { + bridge_bus_number = vmd->busn_start[VMD_BUS_1]; + if (pci_bus_number == VMD_PRIMARY_BUS1) + pci_bus_number = vmd->busn_start[VMD_BUS_1]; + } + + busnr = pci_bus_number - bridge_bus_number; /* * The address computation below is only applicable to relative bus * numbers below 32. */ - if (busnr > 31) + if (busnr < 0 || busnr > 31) return NULL; addr = (busnr << 24) | ((u32)pci_dev->devfn << 16) | 0x8000FFFFU; @@ -1186,6 +1220,7 @@ static int vmd_create_bus(struct vmd_dev *vmd, enum vmd_rootbus bus_number, struct pci_sysdata *sd, resource_size_t *offset, u8 primary) { + u8 root_busnr; u8 cfgbar = bus_number * 3; u8 membar1 = cfgbar + 1; u8 membar2 = cfgbar + 2; @@ -1198,8 +1233,27 @@ static int vmd_create_bus(struct vmd_dev *vmd, enum vmd_rootbus bus_number, pci_add_resource_offset(&resources, &vmd->resources[membar2], offset[1]); - vmd_bus = pci_create_root_bus(&vmd->dev->dev, - vmd->busn_start[bus_number], &vmd_ops, sd, + /* + * Register BUS1 with its logical root number (0x80) up front so PCI core + * bridge scanning does not see a post-registration bus-number mutation. + * + * This is a workaround for pci_scan_bridge_extend() code. + * It marks bridge invalid configuration when detecting a + * non-zero (0x80) the VMD BUS1 root bus number. Thus Primary Bus Number + * of Root Ports on BUS1 is deconfigured in the first pass of + * pci_scan_bridge() to be re-assigned to 0x0 in the second pass. + * As a result no subordinate bus number behind VMD BUS1 is found. + * Workaround: VMD_BUS_1 bus number shall be set to VMD_PRIMARY_BUS1 so it has + * the same value as vmd->bus[VMD_BUS_1]->primary, it will bypass bus number + * reconfiguration. + */ + + if (bus_number == VMD_BUS_1 && vmd->bus1_rootbus) + root_busnr = VMD_PRIMARY_BUS1; + else + root_busnr = vmd->busn_start[bus_number]; + + vmd_bus = pci_create_root_bus(&vmd->dev->dev, root_busnr, &vmd_ops, sd, &resources); if (!vmd_bus) { -- 2.43.0