From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id DA20C1A092A for ; Tue, 13 Oct 2015 14:28:53 +1100 (AEDT) Received: from e23smtp06.au.ibm.com (e23smtp06.au.ibm.com [202.81.31.148]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id B2E93140FDB for ; Tue, 13 Oct 2015 14:28:53 +1100 (AEDT) Received: from /spool/local by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 13 Oct 2015 13:28:52 +1000 Received: from d23relay10.au.ibm.com (d23relay10.au.ibm.com [9.190.26.77]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 8859F3578053 for ; Tue, 13 Oct 2015 14:28:49 +1100 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t9D3Sfgw25624792 for ; Tue, 13 Oct 2015 14:28:49 +1100 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t9D3SGS9016516 for ; Tue, 13 Oct 2015 14:28:17 +1100 Date: Tue, 13 Oct 2015 14:27:52 +1100 From: Gavin Shan To: Wei Yang Cc: Gavin Shan , aik@ozlabs.ru, benh@kernel.crashing.org, linuxppc-dev@ozlabs.org, mpe@ellerman.id.au Subject: Re: [PATCH V5 2/6] powerpc/powernv: simplify the calculation of iov resource alignment Message-ID: <20151013032752.GB21017@gwshan> Reply-To: Gavin Shan References: <1444358816-8163-1-git-send-email-weiyang@linux.vnet.ibm.com> <1444358816-8163-3-git-send-email-weiyang@linux.vnet.ibm.com> <20151013001350.GA21778@gwshan> <20151013024545.GC1437@Richards-MacBook-Pro.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20151013024545.GC1437@Richards-MacBook-Pro.local> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Oct 13, 2015 at 10:45:45AM +0800, Wei Yang wrote: >On Tue, Oct 13, 2015 at 11:13:50AM +1100, Gavin Shan wrote: >>On Fri, Oct 09, 2015 at 10:46:52AM +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 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 >>>Reviewed-by: Gavin Shan >>>Acked-by: Alexey Kardashevskiy >>>--- >>> arch/powerpc/platforms/powernv/pci-ioda.c | 20 ++++++++++++-------- >>> 1 file changed, 12 insertions(+), 8 deletions(-) >>> >>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c >>>index 8c031b5..7da476b 100644 >>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c >>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c >>>@@ -2988,17 +2988,21 @@ 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 returns the total IOV BAR size if M64 BAR is in >>>+ * Shared PE mode or just the individual size if not. >>>+ */ >> >>s/the invidial size/VF BAR size >> >>> align = pci_iov_resource_size(pdev, resno); >>>- if (pdn->vfs_expanded) >>>- return pdn->vfs_expanded * align; >>>+ if (!pdn->vfs_expanded) >>>+ return align; >>> >>>- return align; >>>+ return pdn->vfs_expanded * align; >> >>There is no difference before/after the changes. why this change is needed? >> > >After change the logic is more clear. > >Alignment equals to the total size when IOV BAR is expanded or equals to the >VF BAR size. We don't need to check whether IOV BAR is truncated. > I didn't get what you're talking about with "IOV BAR is truncated". I also didn't get what has been really changed from last 3 lines changes. if (pdn->vfs_expanded) if (!pdn->vfs_expanded) return pdn->vfs_expanded * align; return align; return align; return pdn->vfs_expanded * align; >>> } >>> #endif /* CONFIG_PCI_IOV */ >>> >>>-- >>>2.5.0 >>> > >-- >Richard Yang >Help you, Help me