linux-kernel - Re: [PATCH 10/11] XEN / PCI: Remove the dependence on arch x86 when PCI

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <556494D9.9090007@oracle.com>
Date:	Tue, 26 May 2015 11:44:25 -0400
From:	Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:	Tomasz Nowicki <tomasz.nowicki@...aro.org>,
	Hanjun Guo <hanjun.guo@...aro.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Arnd Bergmann <arnd@...db.de>,
	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will.deacon@....com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>
CC:	Jiang Liu <jiang.liu@...ux.intel.com>,
	Liviu Dudau <Liviu.Dudau@....com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Yijing Wang <wangyijing@...wei.com>,
	Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>,
	Suravee Suthikulpanit <Suravee.Suthikulpanit@....com>,
	Mark Salter <msalter@...hat.com>, linux-pci@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-acpi@...r.kernel.org,
	linux-kernel@...r.kernel.org, linaro-acpi@...ts.linaro.org,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Stefano Stabellini <Stefano.Stabellini@...citrix.com>
Subject: Re: [PATCH 10/11] XEN / PCI: Remove the dependence on arch x86 when
 PCI_MMCONFIG=y

On 05/26/2015 10:54 AM, Tomasz Nowicki wrote:
> On 26.05.2015 16:00, Boris Ostrovsky wrote:
>> On 05/26/2015 09:54 AM, Boris Ostrovsky wrote:
>>> On 05/26/2015 08:49 AM, Hanjun Guo wrote:
>>>> In drivers/xen/pci.c, there are arch x86 dependent codes when
>>>> CONFIG_PCI_MMCONFIG is enabled, since CONFIG_PCI_MMCONFIG
>>>> depends on ACPI, so this will prevent XEN PCI running on other
>>>> architectures using ACPI with PCI_MMCONFIG enabled (such as ARM64).
>>>>
>>>> Fortunatly, it can be sloved in a simple way. In drivers/xen/pci.c,
>>>> the only x86 dependent code is if ((pci_probe & PCI_PROBE_MMCONF) ==
>>>> 0),
>>>> and it's defined in asm/pci_x86.h, the code means that
>>>> if the PCI resource is not probed in PCI_PROBE_MMCONF way, just
>>>> ingnore the xen mcfg init. Actually this is duplicate, because
>>>> if PCI resource is not probed in PCI_PROBE_MMCONF way, the
>>>> pci_mmconfig_list will be empty, and the if (list_empty())
>>>> after it will do the same job.
>>>>
>>>> So just remove the arch related code and the head file, this
>>>> will be no functional change for x86, and also makes xen/pci.c
>>>> usable for other architectures.
>>>>
>>>> Signed-off-by: Hanjun Guo <hanjun.guo@...aro.org>
>>>> CC: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
>>>> CC: Boris Ostrovsky <boris.ostrovsky@...cle.com>
>>>> ---
>>>>   drivers/xen/pci.c | 6 ------
>>>>   1 file changed, 6 deletions(-)
>>>>
>>>> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
>>>> index 6785ebb..9a8dbe3 100644
>>>> --- a/drivers/xen/pci.c
>>>> +++ b/drivers/xen/pci.c
>>>> @@ -28,9 +28,6 @@
>>>>   #include <asm/xen/hypervisor.h>
>>>>   #include <asm/xen/hypercall.h>
>>>>   #include "../pci/pci.h"
>>>> -#ifdef CONFIG_PCI_MMCONFIG
>>>> -#include <asm/pci_x86.h>
>>>> -#endif
>>>>
>>>>   static bool __read_mostly pci_seg_supported = true;
>>>>
>>>> @@ -222,9 +219,6 @@ static int __init xen_mcfg_late(void)
>>>>       if (!xen_initial_domain())
>>>>           return 0;
>>>>
>>>> -    if ((pci_probe & PCI_PROBE_MMCONF) == 0)
>>>> -        return 0;
>>>> -
>>>>       if (list_empty(&pci_mmcfg_list))
>>>>           return 0;
>>>>
>>>
>>> (+Stefano who is Xen ARM maintainer)
>>>
>>> This will not build on x86 since pci_mmcfg_list since, for example,
>>> pci_mmcfg_list is declared in pci_x86.h.
>>
>>
>> And now really with Stefano and with parsable first sentence, sorry:
>>
>>
>> This will not build on x86 since pci_mmcfg_list, for example, is
>> declared in pci_x86.h.
>
> With this patch set, not any more. Please see preceding patches.


OK, I didn't notice this was part of a series.

Then if not having PCI_PROBE_MMCONF bit set is indeed equivalent to 
list_empty(&pci_mmcfg_list), is there any reason for this flag to 
(continue to) exist? (and also for pci_mmcfg_arch_init_failed.)


-boris



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