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authorYijing Wang <wangyijing@huawei.com>2015-01-28 09:52:17 +0800
committerBjorn Helgaas <bhelgaas@google.com>2015-01-28 09:25:57 -0600
commit6a878e5085fe97bd1e222b7883a1b815fcbbe4ed (patch)
tree2ffcc34c8799f2c387c46c3441aa8c1072000e03 /drivers/pci/msi.c
parent97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff)
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PCI: Fail MSI-X mappings if there's no space assigned to MSI-X BAR
Unlike MSI, which is configured via registers in the MSI capability in Configuration Space, MSI-X is configured via tables in Memory Space. These MSI-X tables are mapped by a device BAR, and if no Memory Space has been assigned to the BAR, MSI-X cannot be used. Fail MSI-X setup if no space has been assigned for the BAR. Previously, we ioremapped the MSI-X table even if the resource hadn't been assigned. In this case, the resource address is undefined (and is often zero), which may lead to warnings or oopses in this path: pci_enable_msix msix_capability_init msix_map_region ioremap_nocache The PCI core sets resource flags to zero when it can't assign space for the resource (see reset_resource()). There are also some cases where it sets the IORESOURCE_UNSET flag, e.g., pci_reassigndev_resource_alignment(), pci_assign_resource(), etc. So we must check for both cases. [bhelgaas: changelog] Reported-by: Zhang Jukuo <zhangjukuo@huawei.com> Tested-by: Zhang Jukuo <zhangjukuo@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/msi.c')
-rw-r--r--drivers/pci/msi.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index fd60806..c3e7dfc 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -694,11 +694,16 @@ static void __iomem *msix_map_region(struct pci_dev *dev, unsigned nr_entries)
{
resource_size_t phys_addr;
u32 table_offset;
+ unsigned long flags;
u8 bir;
pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
&table_offset);
bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
+ flags = pci_resource_flags(dev, bir);
+ if (!flags || (flags & IORESOURCE_UNSET))
+ return NULL;
+
table_offset &= PCI_MSIX_TABLE_OFFSET;
phys_addr = pci_resource_start(dev, bir) + table_offset;
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