From 6a878e5085fe97bd1e222b7883a1b815fcbbe4ed Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Wed, 28 Jan 2015 09:52:17 +0800 Subject: 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 Tested-by: Zhang Jukuo Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas --- drivers/pci/msi.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/pci') diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index fd60806d3fd0..c3e7dfcf9ff5 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; -- cgit v1.2.3