PCI: designware: Require config accesses to be naturally aligned

Add sanity checks on "addr" input parameter in dw_pcie_cfg_read() and
dw_pcie_cfg_write().  These checks make sure that accesses are aligned on
their size, e.g., a 4-byte config access is aligned on a 4-byte boundary.

[bhelgaas: changelog, set *val = 0 in failure case]
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Pratyush Anand <pratyush.anand@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 759cd0a50910..b77535f3967b 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -82,6 +82,11 @@ static inline struct pcie_port *sys_to_pcie(struct pci_sys_data *sys)
 
 int dw_pcie_cfg_read(void __iomem *addr, int size, u32 *val)
 {
+        if ((uintptr_t)addr & (size - 1)) {
+                *val = 0;
+                return PCIBIOS_BAD_REGISTER_NUMBER;
+        }
+
         if (size == 4)
                 *val = readl(addr);
         else if (size == 2)
@@ -98,6 +103,9 @@ int dw_pcie_cfg_read(void __iomem *addr, int size, u32 *val)
 
 int dw_pcie_cfg_write(void __iomem *addr, int size, u32 val)
 {
+        if ((uintptr_t)addr & (size - 1))
+                return PCIBIOS_BAD_REGISTER_NUMBER;
+
         if (size == 4)
                 writel(val, addr);
         else if (size == 2)