Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753725AbaAIDMt (ORCPT <rfc822;w@1wt.eu>);
	Wed, 8 Jan 2014 22:12:49 -0500
Received: from szxga01-in.huawei.com ([119.145.14.64]:50585 "EHLO
	szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753338AbaAIDMp (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 8 Jan 2014 22:12:45 -0500
Message-ID: <52CE131A.3020103@huawei.com>
Date: Thu, 9 Jan 2014 11:10:18 +0800
From: Yijing Wang <wangyijing@huawei.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1
MIME-Version: 1.0
To: Jiang Liu <jiang.liu@linux.intel.com>, Joerg Roedel <joro@8bytes.org>,
        David Woodhouse <dwmw2@infradead.org>, Yinghai Lu <yinghai@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Vinod Koul <vinod.koul@intel.com>
CC: Ashok Raj <ashok.raj@intel.com>, Tony Luck <tony.luck@intel.com>,
        <iommu@lists.linux-foundation.org>, <linux-pci@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <dmaengine@vger.kernel.org>
Subject: Re: [Patch Part2 V1 07/14] iommu/vt-d: fix error in detect ATS capability
References: <1389085234-22296-1-git-send-email-jiang.liu@linux.intel.com> <1389085234-22296-8-git-send-email-jiang.liu@linux.intel.com>
In-Reply-To: <1389085234-22296-8-git-send-email-jiang.liu@linux.intel.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Originating-IP: [10.177.27.212]
X-CFilter-Loop: Reflected
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

This is a issue, our BIOS also supports several ATSR which have the same segment.
Good fix :)

On 2014/1/7 17:00, Jiang Liu wrote:
> Current Intel IOMMU driver only matches a PCIe root port with the first
> DRHD unit with the samge segment number. It will report false result
> if there are multiple DRHD units with the same segment number, thus fail
> to detect ATS capability for some PCIe devices.
> 
> This patch refines function dmar_find_matched_atsr_unit() to search all
> DRHD units with the same segment number.
> 
> An example DMAR table entries as below:
> [1D0h 0464  2]                Subtable Type : 0002 <Root Port ATS Capability>
> [1D2h 0466  2]                       Length : 0028
> [1D4h 0468  1]                        Flags : 00
> [1D5h 0469  1]                     Reserved : 00
> [1D6h 0470  2]           PCI Segment Number : 0000
> 
> [1D8h 0472  1]      Device Scope Entry Type : 02
> [1D9h 0473  1]                 Entry Length : 08
> [1DAh 0474  2]                     Reserved : 0000
> [1DCh 0476  1]               Enumeration ID : 00
> [1DDh 0477  1]               PCI Bus Number : 00
> [1DEh 0478  2]                     PCI Path : [02, 00]
> 
> [1E0h 0480  1]      Device Scope Entry Type : 02
> [1E1h 0481  1]                 Entry Length : 08
> [1E2h 0482  2]                     Reserved : 0000
> [1E4h 0484  1]               Enumeration ID : 00
> [1E5h 0485  1]               PCI Bus Number : 00
> [1E6h 0486  2]                     PCI Path : [03, 00]
> 
> [1E8h 0488  1]      Device Scope Entry Type : 02
> [1E9h 0489  1]                 Entry Length : 08
> [1EAh 0490  2]                     Reserved : 0000
> [1ECh 0492  1]               Enumeration ID : 00
> [1EDh 0493  1]               PCI Bus Number : 00
> [1EEh 0494  2]                     PCI Path : [03, 02]
> 
> [1F0h 0496  1]      Device Scope Entry Type : 02
> [1F1h 0497  1]                 Entry Length : 08
> [1F2h 0498  2]                     Reserved : 0000
> [1F4h 0500  1]               Enumeration ID : 00
> [1F5h 0501  1]               PCI Bus Number : 00
> [1F6h 0502  2]                     PCI Path : [03, 03]
> 
> [1F8h 0504  2]                Subtable Type : 0002 <Root Port ATS Capability>
> [1FAh 0506  2]                       Length : 0020
> [1FCh 0508  1]                        Flags : 00
> [1FDh 0509  1]                     Reserved : 00
> [1FEh 0510  2]           PCI Segment Number : 0000
> 
> [200h 0512  1]      Device Scope Entry Type : 02
> [201h 0513  1]                 Entry Length : 08
> [202h 0514  2]                     Reserved : 0000
> [204h 0516  1]               Enumeration ID : 00
> [205h 0517  1]               PCI Bus Number : 40
> [206h 0518  2]                     PCI Path : [02, 00]
> 
> [208h 0520  1]      Device Scope Entry Type : 02
> [209h 0521  1]                 Entry Length : 08
> [20Ah 0522  2]                     Reserved : 0000
> [20Ch 0524  1]               Enumeration ID : 00
> [20Dh 0525  1]               PCI Bus Number : 40
> [20Eh 0526  2]                     PCI Path : [02, 02]
> 
> [210h 0528  1]      Device Scope Entry Type : 02
> [211h 0529  1]                 Entry Length : 08
> [212h 0530  2]                     Reserved : 0000
> [214h 0532  1]               Enumeration ID : 00
> [215h 0533  1]               PCI Bus Number : 40
> [216h 0534  2]                     PCI Path : [03, 00]
> 
> [218h 0536  2]                Subtable Type : 0002 <Root Port ATS Capability>
> [21Ah 0538  2]                       Length : 0020
> [21Ch 0540  1]                        Flags : 00
> [21Dh 0541  1]                     Reserved : 00
> [21Eh 0542  2]           PCI Segment Number : 0000
> 
> [220h 0544  1]      Device Scope Entry Type : 02
> [221h 0545  1]                 Entry Length : 08
> [222h 0546  2]                     Reserved : 0000
> [224h 0548  1]               Enumeration ID : 00
> [225h 0549  1]               PCI Bus Number : 80
> [226h 0550  2]                     PCI Path : [02, 00]
> 
> [228h 0552  1]      Device Scope Entry Type : 02
> [229h 0553  1]                 Entry Length : 08
> [22Ah 0554  2]                     Reserved : 0000
> [22Ch 0556  1]               Enumeration ID : 00
> [22Dh 0557  1]               PCI Bus Number : 80
> [22Eh 0558  2]                     PCI Path : [02, 02]
> 
> [230h 0560  1]      Device Scope Entry Type : 02
> [231h 0561  1]                 Entry Length : 08
> [232h 0562  2]                     Reserved : 0000
> [234h 0564  1]               Enumeration ID : 00
> [235h 0565  1]               PCI Bus Number : 80
> [236h 0566  2]                     PCI Path : [03, 00]
> 
> [238h 0568  2]                Subtable Type : 0002 <Root Port ATS Capability>
> [23Ah 0570  2]                       Length : 0020
> [23Ch 0572  1]                        Flags : 00
> [23Dh 0573  1]                     Reserved : 00
> [23Eh 0574  2]           PCI Segment Number : 0000
> 
> [240h 0576  1]      Device Scope Entry Type : 02
> [241h 0577  1]                 Entry Length : 08
> [242h 0578  2]                     Reserved : 0000
> [244h 0580  1]               Enumeration ID : 00
> [245h 0581  1]               PCI Bus Number : C0
> [246h 0582  2]                     PCI Path : [02, 00]
> 
> [248h 0584  1]      Device Scope Entry Type : 02
> [249h 0585  1]                 Entry Length : 08
> [24Ah 0586  2]                     Reserved : 0000
> [24Ch 0588  1]               Enumeration ID : 00
> [24Dh 0589  1]               PCI Bus Number : C0
> [24Eh 0590  2]                     PCI Path : [02, 02]
> 
> [250h 0592  1]      Device Scope Entry Type : 02
> [251h 0593  1]                 Entry Length : 08
> [252h 0594  2]                     Reserved : 0000
> [254h 0596  1]               Enumeration ID : 00
> [255h 0597  1]               PCI Bus Number : C0
> [256h 0598  2]                     PCI Path : [03, 00]
> 
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> ---
>  drivers/iommu/intel-iommu.c |   37 +++++++++++++++++--------------------
>  1 file changed, 17 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 7038b38..b0028e2 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -3556,37 +3556,34 @@ int dmar_find_matched_atsr_unit(struct pci_dev *dev)
>  {
>  	int i;
>  	struct pci_bus *bus;
> +	struct pci_dev *bridge = NULL;
>  	struct acpi_dmar_atsr *atsr;
>  	struct dmar_atsr_unit *atsru;
>  
>  	dev = pci_physfn(dev);
> -
> -	list_for_each_entry(atsru, &dmar_atsr_units, list) {
> -		atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
> -		if (atsr->segment == pci_domain_nr(dev->bus))
> -			goto found;
> -	}
> -
> -	return 0;
> -
> -found:
>  	for (bus = dev->bus; bus; bus = bus->parent) {
> -		struct pci_dev *bridge = bus->self;
> -
> +		bridge = bus->self;
>  		if (!bridge || !pci_is_pcie(bridge) ||
>  		    pci_pcie_type(bridge) == PCI_EXP_TYPE_PCI_BRIDGE)
>  			return 0;
> -
> -		if (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT) {
> -			for (i = 0; i < atsru->devices_cnt; i++)
> -				if (atsru->devices[i] == bridge)
> -					return 1;
> +		if (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT)
>  			break;
> -		}
>  	}
> +	if (!bridge)
> +		return 0;
>  
> -	if (atsru->include_all)
> -		return 1;
> +	list_for_each_entry_rcu(atsru, &dmar_atsr_units, list) {
> +		atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
> +		if (atsr->segment != pci_domain_nr(dev->bus))
> +			continue;
> +
> +		for (i = 0; i < atsru->devices_cnt; i++)
> +			if (atsru->devices[i] == bridge)
> +				return 1;
> +
> +		if (atsru->include_all)
> +			return 1;
> +	}
>  
>  	return 0;
>  }
> 


-- 
Thanks!
Yijing

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/