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Subject: Re: [PATCH v2 1/3] PCI: endpoint: Handle 64-bit BARs properly
To:     Bjorn Helgaas <helgaas@kernel.org>
References: <20180208123346.20784-1-niklas.cassel@axis.com>
 <20180208123346.20784-2-niklas.cassel@axis.com>
 <da5004d3-c3e8-d9fd-6698-3b12c3ab624a@ti.com>
 <20180208215735.GD98765@bhelgaas-glaptop.roam.corp.google.com>
CC:     Niklas Cassel <niklas.cassel@axis.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Sekhar Nori <nsekhar@ti.com>,
        Cyrille Pitchen <cyrille.pitchen@free-electrons.com>,
        Niklas Cassel <niklass@axis.com>,
        Shawn Lin <shawn.lin@rock-chips.com>,
        John Keeping <john@metanate.com>, <linux-pci@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
From:   Kishon Vijay Abraham I <kishon@ti.com>
Message-ID: <5e54c525-1b78-bef3-7f83-82eb872837da@ti.com>
Date:   Fri, 9 Feb 2018 18:14:49 +0530
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Hi Bjorn,

On Friday 09 February 2018 03:27 AM, Bjorn Helgaas wrote:
> On Thu, Feb 08, 2018 at 06:17:32PM +0530, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Thursday 08 February 2018 06:03 PM, Niklas Cassel wrote:
>>> A 64-bit BAR uses the succeeding BAR for the upper bits, therefore
>>> we cannot call pci_epc_set_bar() on a BAR that follows a 64-bit BAR.
>>>
>>> If pci_epc_set_bar() is called with flag PCI_BASE_ADDRESS_MEM_TYPE_64,
>>
>> Not related to $patch. But I have a query on when
>> PCI_BASE_ADDRESS_MEM_TYPE_64 should be set. Whether if the size is >
>> 4G or if the address can be mapped anywhere in the 64-bit PCIe
>> address space or both?
> 
> In general, PCI_BASE_ADDRESS_MEM_TYPE_64 should be set if the BAR is
> 64 bits wide.  IORESOURCE_MEM_64 is similar.

okay, if the HW support 64bit BAR, 64 bit flag should be set and not based on
size or anything else?

Thanks
Kishon