From: Alexey Kardashevskiy <aik@ozlabs•ru>
To: Wei Yang <weiyang@linux•vnet.ibm.com>
Cc: Gavin Shan <gwshan@linux•vnet.ibm.com>, linuxppc-dev@ozlabs•org
Subject: Re: [PATCH V2 2/6] powerpc/powernv: simplify the calculation of iov resource
Date: Thu, 6 Aug 2015 20:15:55 +1000 [thread overview]
Message-ID: <55C333DB.4080406@ozlabs.ru> (raw)
In-Reply-To: <20150806094102.GB13055@richard>
On 08/06/2015 07:41 PM, Wei Yang wrote:
> On Thu, Aug 06, 2015 at 07:00:00PM +1000, Alexey Kardashevskiy wrote:
>> On 08/06/2015 02:51 PM, Gavin Shan wrote:
>>> On Wed, Aug 05, 2015 at 09:24:59AM +0800, Wei Yang wrote:
>>>> The alignment of IOV BAR on PowerNV platform is the total size of the IOV
>>>> BAR. No matter whether the IOV BAR is truncated or not, the total size
>>>> could be calculated by (vfs_expanded * VF size).
>>>>
>>>
>>> s/VF size/VF BAR size
>>>
>>> I think the changelog would be more explicit:
>>>
>>> The alignment of IOV BAR on PowerNV platform is the total size of the
>>> IOV BAR, no matter whether the IOV BAR is extended with number of max
>>> VFs or number of max PE number (256). The alignment can be calculated
>>> by (vfs_expaned * VF_BAR_size).
>>
>>
>>
>> Is that really a PowerNV-specific requirement or it is valid for
>> every platform (I suspect this is the case here)?
>>
>
> Currently, it is PowerNV-specific.
How is x86 different on this matter?
Why would we need this extra alignment, not just VF's BAR alignment?
>>
>> Also, what is the exact meaning of "expanded" in @vfs_expanded? It is
>> either 255 (if individual VF BARs are <= 64MB) or
>> roundup_pow_of_two(total_vfs) (which is something like 4 or 16). What
>> is expanded here?
>>
>
> PF's IOV BAR original size is (VF BAR size * total_vfs).
>
> After expanding, the IOV BAR size is (VF BAR size * 256) or (VF BAR size *
> roundup_pow_of_two(total_vfs)).
Ufff, got it now. I'd store just an expanded IOV BAR size (not some magic
VFs number) because this is what it actually is:
pdn->vfs_expanded * align
>>
>>>
>>>> This patch simplifies the pnv_pci_iov_resource_alignment() by removing the
>>>> first case.
>>>>
>>>> Signed-off-by: Wei Yang <weiyang@linux•vnet.ibm.com>
>>>
>>> Reviewed-by: Gavin Shan <gwshan@linux•vnet.ibm.com>
>>>
>>>> ---
>>>> arch/powerpc/platforms/powernv/pci-ioda.c | 14 +++++++++-----
>>>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>> index 9b41dba..7192e62 100644
>>>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>> @@ -2987,12 +2987,16 @@ static resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
>>>> int resno)
>>>> {
>>>> struct pci_dn *pdn = pci_get_pdn(pdev);
>>>> - resource_size_t align, iov_align;
>>>> -
>>>> - iov_align = resource_size(&pdev->resource[resno]);
>>>> - if (iov_align)
>>>> - return iov_align;
>>>> + resource_size_t align;
>>>>
>>>> + /*
>>>> + * On PowerNV platform, IOV BAR is mapped by M64 BAR to enable the
>>>> + * SR-IOV. While from hardware perspective, the range mapped by M64
>>>> + * BAR should be size aligned.
>>>> + *
>>>> + * This function return the total IOV BAR size if expanded or just the
>>>> + * individual size if not.
>>>> + */
>>>> align = pci_iov_resource_size(pdev, resno);
>>>> if (pdn->vfs_expanded)
>>>> return pdn->vfs_expanded * align;
>>>> --
>>>> 1.7.9.5
>>>>
>>>
>>
>>
>> --
>> Alexey
>
--
Alexey
next prev parent reply other threads:[~2015-08-06 10:16 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-29 7:22 [PATCH] powerpc/powernv: use one M64 BAR in Single PE mode for one VF BAR Wei Yang
2015-07-30 1:15 ` Gavin Shan
2015-07-30 5:43 ` Wei Yang
2015-07-31 0:13 ` Gavin Shan
2015-07-31 2:01 ` Wei Yang
2015-08-05 1:24 ` [PATCH V2 0/6] Redesign SR-IOV on PowerNV Wei Yang
2015-08-05 1:24 ` [PATCH V2 1/6] powerpc/powernv: don't enable SRIOV when VF BAR contains non M64 BAR Wei Yang
2015-08-06 4:35 ` Gavin Shan
2015-08-06 6:10 ` Alexey Kardashevskiy
2015-08-06 6:57 ` Gavin Shan
2015-08-06 7:47 ` Alexey Kardashevskiy
2015-08-06 11:07 ` Gavin Shan
2015-08-06 14:13 ` Wei Yang
2015-08-07 1:24 ` Alexey Kardashevskiy
2015-08-06 14:10 ` Wei Yang
2015-08-07 1:20 ` Gavin Shan
2015-08-07 2:24 ` Wei Yang
2015-08-07 3:50 ` Gavin Shan
2015-08-07 7:14 ` Alexey Kardashevskiy
2015-08-10 1:40 ` Wei Yang
2015-08-05 1:24 ` [PATCH V2 2/6] powerpc/powernv: simplify the calculation of iov resource Wei Yang
2015-08-06 4:51 ` Gavin Shan
2015-08-06 9:00 ` Alexey Kardashevskiy
2015-08-06 9:41 ` Wei Yang
2015-08-06 10:15 ` Alexey Kardashevskiy [this message]
2015-08-07 1:36 ` Wei Yang
2015-08-06 13:49 ` Wei Yang
2015-08-07 1:08 ` Gavin Shan
2015-08-05 1:25 ` [PATCH V2 3/6] powerpc/powernv: use one M64 BAR in Single PE mode for one VF BAR Wei Yang
2015-08-06 5:20 ` Gavin Shan
2015-08-06 9:36 ` Wei Yang
2015-08-06 10:07 ` Gavin Shan
2015-08-07 1:48 ` Wei Yang
2015-08-07 8:13 ` Alexey Kardashevskiy
2015-08-06 10:04 ` Alexey Kardashevskiy
2015-08-07 2:01 ` Wei Yang
2015-08-07 8:59 ` Alexey Kardashevskiy
2015-08-10 1:48 ` Wei Yang
2015-08-05 1:25 ` [PATCH V2 4/6] powerpc/powernv: replace the hard coded boundary with gate Wei Yang
2015-08-06 5:26 ` Gavin Shan
2015-08-07 9:11 ` Alexey Kardashevskiy
2015-08-05 1:25 ` [PATCH V2 5/6] powerpc/powernv: boundary the total vf bar size instead of the individual one Wei Yang
2015-08-06 5:28 ` Gavin Shan
2015-08-06 14:03 ` Wei Yang
2015-08-07 1:23 ` Gavin Shan
2015-08-07 2:25 ` Wei Yang
2015-08-05 1:25 ` [PATCH V2 6/6] powerpc/powernv: allocate discrete PE# when using M64 BAR in Single PE mode Wei Yang
2015-08-06 5:36 ` Gavin Shan
2015-08-06 13:41 ` Wei Yang
2015-08-07 1:36 ` Gavin Shan
2015-08-07 2:33 ` Wei Yang
2015-08-07 3:43 ` Gavin Shan
2015-08-07 5:44 ` Wei Yang
2015-08-07 5:54 ` Gavin Shan
2015-08-07 6:25 ` Wei Yang
2015-08-07 10:00 ` Alexey Kardashevskiy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55C333DB.4080406@ozlabs.ru \
--to=aik@ozlabs$(echo .)ru \
--cc=gwshan@linux$(echo .)vnet.ibm.com \
--cc=linuxppc-dev@ozlabs$(echo .)org \
--cc=weiyang@linux$(echo .)vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox