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 A664F1A1E1E for ; Fri, 14 Aug 2015 00:13:08 +1000 (AEST) Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 7ECCF1401B5 for ; Fri, 14 Aug 2015 00:13:08 +1000 (AEST) Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 14 Aug 2015 00:13:07 +1000 Received: from d23relay10.au.ibm.com (d23relay10.au.ibm.com [9.190.26.77]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 0E2A22CE8052 for ; Fri, 14 Aug 2015 00:13:05 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t7DECv7c62783674 for ; Fri, 14 Aug 2015 00:13:05 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t7DECWXq031793 for ; Fri, 14 Aug 2015 00:12:32 +1000 From: Wei Yang To: aik@ozlabs.ru, gwshan@linux.vnet.ibm.com, benh@kernel.crashing.org Cc: linuxppc-dev@ozlabs.org, Wei Yang Subject: [PATCH v3 4/6] powerpc/powernv: replace the hard coded boundary with gate Date: Thu, 13 Aug 2015 22:11:09 +0800 Message-Id: <1439475071-7001-5-git-send-email-weiyang@linux.vnet.ibm.com> In-Reply-To: <1439475071-7001-1-git-send-email-weiyang@linux.vnet.ibm.com> References: <1439475071-7001-1-git-send-email-weiyang@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , At the moment 64bit-prefetchable window can be maximum 64GB, which is currently got from device tree. This means that in shared mode the maximum supported VF BAR size is 64GB/256=256MB. While this size could exhaust the whole 64bit-prefetchable window. This is a design decision to set a boundary to 64MB of the VF BAR size. Since VF BAR size with 64MB would occupy a quarter of the 64bit-prefetchable window, this is affordable. This patch replaces magic limit of 64MB with (m64_segsize >> 1) and adds comment to explain the reason for it. Signed-off-by: Wei Yang --- arch/powerpc/platforms/powernv/pci-ioda.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 4da0f50..3e8c0b4 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -2688,7 +2688,7 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) struct pnv_phb *phb; struct resource *res; int i; - resource_size_t size; + resource_size_t size, gate; struct pci_dn *pdn; int mul, total_vfs; @@ -2704,6 +2704,17 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) total_vfs = pci_sriov_get_totalvfs(pdev); mul = phb->ioda.total_pe; + /* + * If bigger than or equal to half of M64 segment size, just round up + * power of two. + * + * Generally, one M64 BAR maps one IOV BAR. To avoid conflict with + * other devices, IOV BAR size is expanded to be (total_pe * + * VF_BAR_size). When VF_BAR_size is half of M64 segment size , the + * expanded size would equal to half of the whole M64 Space size, + * which will exhaust the M64 Space and limit the system flexibility. + */ + gate = phb->ioda.m64_segsize >> 1; for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) { res = &pdev->resource[i + PCI_IOV_RESOURCES]; @@ -2718,10 +2729,11 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev) size = pci_iov_resource_size(pdev, i + PCI_IOV_RESOURCES); - /* bigger than 64M */ - if (size > (1 << 26)) { - dev_info(&pdev->dev, "PowerNV: VF BAR%d: %pR IOV size is bigger than 64M, roundup power2\n", - i, res); + /* bigger than or equal to gate */ + if (size >= gate) { + dev_info(&pdev->dev, "PowerNV: VF BAR%d: %pR IOV size " + "is bigger than %lld, roundup power2\n", + i, res, gate); mul = roundup_pow_of_two(total_vfs); pdn->m64_single_mode = true; break; -- 1.7.9.5