From: Yongji Xie <xyjxie@linux.vnet.ibm.com>
To: bhelgaas@google.com
Cc: linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
alex.williamson@redhat.com, paulus@samba.org, aik@ozlabs.ru,
gwshan@linux.vnet.ibm.com, benh@kernel.crashing.org,
mpe@ellerman.id.au, zhong@linux.vnet.ibm.com
Subject: [PATCH v6 2/4] PCI: Ignore enforced alignment to VF BARs
Date: Thu, 29 Sep 2016 14:46:19 +0800 [thread overview]
Message-ID: <1475131581-4373-3-git-send-email-xyjxie@linux.vnet.ibm.com> (raw)
In-Reply-To: <1475131581-4373-1-git-send-email-xyjxie@linux.vnet.ibm.com>
VF BARs are read-only zeroes according to SRIOV spec,
the normal way(writing BARs) of allocating resources wouldn't
be applied to VFs. The VFs' resources would be allocated
when we enable SR-IOV capability. So we should not try to
reassign alignment after we enable VFs. It's meaningless
and will release the allocated resources which leads to a bug.
Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com>
---
drivers/pci/pci.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2d85a96..b8357d7 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5048,6 +5048,15 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev)
resource_size_t align, size;
u16 command;
+ /*
+ * VF BARs are RO zero according to SR-IOV spec 3.4.1.11. Their
+ * resources would be allocated when we enable them and not be
+ * re-allocated any more. So we should never try to reassign
+ * VF's alignment here.
+ */
+ if (dev->is_virtfn)
+ return;
+
/* check if specified PCI is target device to reassign */
align = pci_specified_resource_alignment(dev);
if (!align)
--
1.7.9.5
next prev parent reply other threads:[~2016-09-29 6:46 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-29 6:46 [PATCH v6 0/4] PCI: Introduce a way to enforce all MMIO BARs not to share PAGE_SIZE Yongji Xie
2016-09-29 6:46 ` [PATCH v6 1/4] PCI: Ignore enforced alignment when kernel uses existing firmware setup Yongji Xie
2016-09-29 6:46 ` Yongji Xie [this message]
2016-09-29 6:46 ` [PATCH v6 3/4] PCI: Don't change resources' size when using resource_alignment Yongji Xie
2016-09-29 6:46 ` [PATCH v6 4/4] PCI: Add a macro to set default alignment for all PCI devices Yongji Xie
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