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From: tn@semihalf•com (Tomasz Nowicki)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus domain number.
Date: Mon, 2 May 2016 14:43:56 +0200	[thread overview]
Message-ID: <57274B8C.5030304@semihalf.com> (raw)
In-Reply-To: <20160427111758.GA6234@red-moon>

On 04/27/2016 01:17 PM, Lorenzo Pieralisi wrote:
> On Tue, Apr 26, 2016 at 09:26:49PM -0500, Bjorn Helgaas wrote:
>> On Fri, Apr 15, 2016 at 07:06:37PM +0200, Tomasz Nowicki wrote:
[...]
>>   
>> +int acpi_pci_bus_domain_nr(struct device *parent)
>> +{
>> +	struct acpi_device *acpi_dev = to_acpi_device(parent);
>> +	unsigned long long segment = 0;
>> +	acpi_status status;
>> +
>> +	/*
>> +	 * If _SEG method does not exist, following ACPI spec (6.5.6)
>> +	 * all PCI buses belong to domain 0.
>> +	 */
>> +	status = acpi_evaluate_integer(acpi_dev->handle, METHOD_NAME__SEG, NULL,
>> +				       &segment);
>> We already have code in acpi_pci_root_add() to evaluate _SEG.  We
>> don't want to evaluate it *twice*, do we?
>>
>> I was sort of expecting that if you added it here, we'd remove the
>> existing call, but it looks like you're keeping both?
> We can't remove the existing call, since it is used on X86 and IA64
> to store the segment number that, in the process, is used in their
> pci_domain_nr() arch specific callback to retrieve the domain nr.
>
> On ARM64, that selects PCI_DOMAINS_GENERIC, we have to find a way
> to retrieve the domain number that is not arch dependent, since
> this is generic code, we can't rely on any bus->sysdata format (unless
> we do something like JC did below), therefore the only way is to call
> the _SEG method *again* here, which also forced Tomasz to go through
> the ACPI_COMPANION setting song and dance and pass the parent pointer
> to pci_create_root_bus() (see patch 1), which BTW is a source of
> trouble on its own as you noticed.
What trouble in patch 1 do you mean? I may miss something.

I agree that patch 1 is not necessary if we decide to use sysdata or 
rework root bus scanning to move domain to host bridge. Nevertheless, 
patch 1 is still a cleanup IMO.

Thanks,
Tomasz

  parent reply	other threads:[~2016-05-02 12:43 UTC|newest]

Thread overview: 105+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-15 17:06 [PATCH V6 00/13] Support for generic ACPI based PCI host controller Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge device companion assignment to core code Tomasz Nowicki
2016-04-15 20:41   ` kbuild test robot
2016-04-26 22:36     ` Bjorn Helgaas
2016-04-27 10:12       ` Tomasz Nowicki
2016-04-27  2:45   ` Bjorn Helgaas
2016-05-04  8:10     ` Tomasz Nowicki
2016-05-09 22:18       ` Rafael J. Wysocki
2016-05-10 10:27         ` Lorenzo Pieralisi
2016-05-09 22:56   ` Rafael J. Wysocki
2016-05-10  1:53     ` Bjorn Helgaas
2016-05-10 10:07       ` Lorenzo Pieralisi
2016-04-15 17:06 ` [PATCH V6 02/13] pci, acpi: Provide generic way to assign bus domain number Tomasz Nowicki
2016-04-27  2:26   ` Bjorn Helgaas
2016-04-27 11:17     ` Lorenzo Pieralisi
2016-04-27 16:44       ` Bjorn Helgaas
2016-04-27 17:31         ` Lorenzo Pieralisi
2016-04-28  8:13           ` Liviu.Dudau at arm.com
2016-04-28 15:12           ` Bjorn Helgaas
2016-04-28 15:34             ` Arnd Bergmann
2016-04-29 22:50               ` Arnd Bergmann
2016-05-02 12:43       ` Tomasz Nowicki [this message]
2016-05-02 13:26         ` Jayachandran C
2016-05-03 11:02           ` Lorenzo Pieralisi
2016-05-03 14:22             ` Jayachandran C
2016-05-03 14:55               ` Lorenzo Pieralisi
2016-04-27 11:59     ` Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 03/13] x86, ia64: Include acpi_pci_{add|remove}_bus to the default pcibios_{add|remove}_bus implementation Tomasz Nowicki
2016-04-27  2:34   ` Bjorn Helgaas
2016-04-27 13:19     ` Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 04/13] pci, of: Move the PCI I/O space management to PCI core code Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 05/13] acpi, pci: Support IO resources when parsing PCI host bridge resources Tomasz Nowicki
2016-04-27  2:39   ` Bjorn Helgaas
2016-04-27  5:36     ` Jon Masters
2016-04-28 21:53       ` Jon Masters
2016-04-27 14:26     ` Lorenzo Pieralisi
2016-04-27 15:10       ` Liviu.Dudau at arm.com
2016-04-27 16:09         ` Lorenzo Pieralisi
2016-04-28 15:45       ` Bjorn Helgaas
2016-04-15 17:06 ` [PATCH V6 06/13] arm64, pci, acpi: ACPI support for legacy IRQs parsing and consolidation with DT code Tomasz Nowicki
2016-04-27  2:44   ` Bjorn Helgaas
2016-04-27 11:46     ` Lorenzo Pieralisi
2016-04-15 17:06 ` [PATCH V6 07/13] PCI: Provide common functions for ECAM mapping Tomasz Nowicki
2016-04-15 18:41   ` Arnd Bergmann
2016-04-28 21:47   ` Bjorn Helgaas
2016-04-29  8:01     ` Jayachandran C
2016-05-05  9:24       ` Jayachandran C
2016-05-05 10:38         ` Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 08/13] PCI: generic, thunder: update to use generic ECAM API Tomasz Nowicki
2016-04-15 18:39   ` Arnd Bergmann
2016-04-16  7:20     ` Jayachandran C
2016-04-16  7:31       ` Arnd Bergmann
2016-04-16 14:36         ` Jayachandran C
2016-04-18 13:03           ` Tomasz Nowicki
2016-04-18 14:44             ` Arnd Bergmann
2016-04-18 19:31               ` Tomasz Nowicki
2016-04-19 13:06                 ` Arnd Bergmann
2016-04-21  9:28                   ` Tomasz Nowicki
2016-04-21  9:36                     ` Arnd Bergmann
2016-04-21 10:08                       ` Tomasz Nowicki
2016-04-22 14:30                         ` Jon Masters
2016-04-22 16:00                           ` David Daney
2016-04-28 20:14                       ` Bjorn Helgaas
2016-04-28 20:40                         ` Arnd Bergmann
2016-04-28 21:18                           ` Bjorn Helgaas
2016-04-28 21:47                             ` Jon Masters
2016-04-29  9:41                               ` Lorenzo Pieralisi
2016-04-19 21:40   ` Arnd Bergmann
2016-04-20  0:22     ` Jayachandran C
2016-04-15 17:06 ` [PATCH V6 09/13] pci, acpi: Support for ACPI based generic PCI host controller Tomasz Nowicki
2016-04-20 19:12   ` Jayachandran C
2016-04-21  9:06     ` Tomasz Nowicki
2016-04-22 12:49       ` Jayachandran C
2016-04-22 14:40       ` Jon Masters
2016-04-23 15:23         ` Jon Masters
2016-04-28 21:48   ` Bjorn Helgaas
2016-04-29  8:37     ` Lorenzo Pieralisi
2016-04-29 17:35       ` Jayachandran C
2016-05-02 11:31         ` Tomasz Nowicki
2016-05-03  8:46         ` Lorenzo Pieralisi
2016-05-02 11:03     ` Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 10/13] arm64, pci, acpi: Start using ACPI based PCI host controller driver for ARM64 Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 11/13] pci, acpi: Match PCI config space accessors against platfrom specific quirks Tomasz Nowicki
2016-04-18 11:37   ` liudongdong (C)
2016-04-18 12:21     ` Tomasz Nowicki
2016-04-15 17:06 ` [PATCH V6 12/13] pci, pci-thunder-ecam: Add ACPI support for ThunderX ECAM Tomasz Nowicki
2016-04-19 10:26   ` Tomasz Nowicki
2016-04-19 10:41     ` [Linaro-acpi] " G Gregory
2016-04-19 11:12       ` Graeme Gregory
2016-04-19 11:22         ` Tomasz Nowicki
2016-04-19 12:29           ` G Gregory
2016-04-15 17:06 ` [PATCH V6 13/13] pci, pci-thunder-pem: Add ACPI support for ThunderX PEM Tomasz Nowicki
2016-04-15 18:19 ` [PATCH V6 00/13] Support for generic ACPI based PCI host controller Jon Masters
2016-04-16 15:31   ` Jayachandran C
2016-04-18 13:33     ` Tomasz Nowicki
2016-04-18 14:38       ` Arnd Bergmann
2016-04-18 15:26         ` Tomasz Nowicki
2016-04-18 16:14           ` Mark Langsdorf
2016-04-17  9:23   ` Martinez Kristofer
2016-04-16 18:30 ` Duc Dang
2016-04-17  4:18 ` Sinan Kaya
2016-04-22 16:08 ` Robert Richter
2016-04-22 20:46 ` Suravee Suthikulpanit
2016-04-25 17:23 ` Jeremy Linton
2016-04-26  9:07 ` liudongdong (C)

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