public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Alexey Kardashevskiy <aik@ozlabs•ru>
To: Wei Yang <weiyang@linux•vnet.ibm.com>,
	gwshan@linux•vnet.ibm.com, benh@kernel•crashing.org
Cc: linuxppc-dev@ozlabs•org
Subject: Re: [PATCH V4 2/6] powerpc/powernv: simplify the calculation of iov resource alignment
Date: Fri, 2 Oct 2015 18:58:09 +1000	[thread overview]
Message-ID: <560E4721.1090007@ozlabs.ru> (raw)
In-Reply-To: <1439949704-8023-3-git-send-email-weiyang@linux.vnet.ibm.com>

On 08/19/2015 12:01 PM, 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 extended with number of
> roundup_pow_of_two(total_vfs) or number of max PE number (256), the total
> size could be calculated by (vfs_expanded * VF_BAR_size).
>
> 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 8c031b5..e3e0acb 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -2988,12 +2988,16 @@ 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.


Out of curiosity - IOV BAR does NOT have to be aligned on other platforms?


> +	 *
> +	 * This function returns the total IOV BAR size if expanded or just the
> +	 * individual size if not.

Expanded vs. non-expanded means "using shared M64" (when it is split by 256 
segments) vs. "using entire M64"?


> +	 */
>   	align = pci_iov_resource_size(pdev, resno);
>   	if (pdn->vfs_expanded)
>   		return pdn->vfs_expanded * align;
>


-- 
Alexey

  reply	other threads:[~2015-10-02  8:58 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-19  2:01 [PATCH V4 0/6] Redesign SR-IOV on PowerNV Wei Yang
2015-08-19  2:01 ` [PATCH V4 1/6] powerpc/powernv: don't enable SRIOV when VF BAR has non 64bit-prefetchable BAR Wei Yang
2015-10-02  8:55   ` Alexey Kardashevskiy
2015-10-08  6:29     ` Wei Yang
2015-08-19  2:01 ` [PATCH V4 2/6] powerpc/powernv: simplify the calculation of iov resource alignment Wei Yang
2015-10-02  8:58   ` Alexey Kardashevskiy [this message]
2015-10-08  6:39     ` Wei Yang
2015-08-19  2:01 ` [PATCH V4 3/6] powerpc/powernv: use one M64 BAR in Single PE mode for one VF BAR Wei Yang
2015-08-19  2:21   ` Gavin Shan
2015-10-02  9:29   ` Alexey Kardashevskiy
2015-10-08  7:06     ` Wei Yang
2015-08-19  2:01 ` [PATCH V4 4/6] powerpc/powernv: replace the hard coded boundary with gate Wei Yang
2015-08-19  2:01 ` [PATCH V4 5/6] powerpc/powernv: boundary the total VF BAR size instead of the individual one Wei Yang
2015-10-02  9:51   ` Alexey Kardashevskiy
2015-10-08  7:13     ` Wei Yang
2015-08-19  2:01 ` [PATCH V4 6/6] powerpc/powernv: allocate sparse PE# when using M64 BAR in Single PE mode Wei Yang
2015-08-19  2:21   ` Gavin Shan
2015-10-02 10:05   ` Alexey Kardashevskiy
2015-10-08  7:19     ` Wei Yang
2015-08-26  5:11 ` [PATCH V4 0/6] Redesign SR-IOV on PowerNV Alexey Kardashevskiy
2015-08-26  8:06   ` Alexey Kardashevskiy
2015-10-02 10:07 ` Alexey Kardashevskiy
2015-10-07  2:43   ` Michael Ellerman

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=560E4721.1090007@ozlabs.ru \
    --to=aik@ozlabs$(echo .)ru \
    --cc=benh@kernel$(echo .)crashing.org \
    --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