On Tue, Aug 19, 2014 at 03:44:59PM -0600, Bjorn Helgaas wrote:
>On Thu, Jul 24, 2014 at 02:22:12PM +0800, Wei Yang wrote:
>> Current implementation calculates VF BAR size from dividing the total size of
>> IOV BAR by total VF number. It won't work on PowerNV platform because we're
>> going to expand IOV BAR size for finely alignment.
>>
>> The patch enforces getting IOV BAR size from hardware and then calculate
>> the VF BAR size based on that when platform wants so.
>>
>> Signed-off-by: Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/pci/iov.c | 28 ++++++++++++++++++++++++----
>> include/linux/ioport.h | 1 +
>> 2 files changed, 25 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
>> index 7566238..ef1c546 100644
>> --- a/drivers/pci/iov.c
>> +++ b/drivers/pci/iov.c
>> @@ -55,6 +55,9 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
>> struct resource *res;
>> struct pci_sriov *iov = dev->sriov;
>> struct pci_bus *bus;
>> + struct resource tmp;
>> + enum pci_bar_type type;
>> + int reg;
>>
>> mutex_lock(&iov->dev->sriov->lock);
>> bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id));
>> @@ -80,12 +83,29 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
>> continue;
>> virtfn->resource[i].name = pci_name(virtfn);
>> virtfn->resource[i].flags = res->flags;
>> - size = resource_size(res);
>> - do_div(size, iov->total_VFs);
>> + /* When res has IORESOURCE_ARCH, retrieve the IOV BAR size
>> + * from hardware directly.
>> + */
>> + if (res->flags & IORESOURCE_ARCH) {
>> + reg = pci_iov_resource_bar(dev, i + PCI_IOV_RESOURCES, &type);
>> + __pci_read_base(dev, type, &tmp, reg);
>> + size = resource_size(&tmp);
>> + /* When __pci_read_base fails, flags is set to 0.
>> + * In this case, reset size to 0, which means the VF
>> + * will not be enabled.
>> + */
>> + if (!tmp.flags)
>> + size = 0;
>
>I don't like the IORESOURCE_ARCH flag because it really doesn't have any
>specific meaning. You're using it to enable some arch-specific code here
>for this specific case. But there are any number of other places that
>could do something similar, and there's no way to coordinate them all.
>
>I'd rather have some sort of pcibios_*() hook here where powerpc could
>override the default implementation.
Yep, got it. I will write a pcibios_sriov_resource_size() and override it in
powerpc arch.
>
>> + } else {
>> + size = resource_size(res);
>> + do_div(size, iov->total_VFs);
>> + }
>> virtfn->resource[i].start = res->start + size * id;
>> virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
>> - rc = request_resource(res, &virtfn->resource[i]);
>> - BUG_ON(rc);
>> + if (resource_size(&virtfn->resource[i])) {
>> + rc = request_resource(res, &virtfn->resource[i]);
>> + BUG_ON(rc);
>> + }
>> }
>>
>> if (reset)
>> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
>> index 5e3a906..de8b57c 100644
>> --- a/include/linux/ioport.h
>> +++ b/include/linux/ioport.h
>> @@ -48,6 +48,7 @@ struct resource {
>> #define IORESOURCE_MEM_64 0x00100000
>> #define IORESOURCE_WINDOW 0x00200000 /* forwarded by bridge */
>> #define IORESOURCE_MUXED 0x00400000 /* Resource is software muxed */
>> +#define IORESOURCE_ARCH 0x00800000 /* Resource arch tagged */
>>
>> #define IORESOURCE_EXCLUSIVE 0x08000000 /* Userland may not map this resource */
>> #define IORESOURCE_DISABLED 0x10000000
>> --
>> 1.7.9.5
>>
--
Richard Yang
Help you, Help me
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