PCI: Check for PCI_HEADER_TYPE_BRIDGE equality, not bitmask

Bit 7 of the "Header Type" register indicates a multi-function device when
set.  Bits 0-6 contain encoded values, where 0x1 indicates a PCI-PCI
bridge.  It is incorrect to test this as though it were a mask.

For example, while the PCI 3.0 spec only defines values 0x0, 0x1, and 0x2,
it's conceivable that a future spec could define 0x3 to mean something
else; then tests for "(hdr_type & 0x7f) & PCI_HEADER_TYPE_BRIDGE" would
incorrectly succeed for this new 0x3 header type.

Test bits 0-6 of the Header Type for equality with PCI_HEADER_TYPE_BRIDGE.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 6 insertions, 6 deletions

diff --git a/drivers/pci/hotplug/ibmphp_pci.c b/drivers/pci/hotplug/ibmphp_pci.c
index 814cea22a9fa..5824df538f72 100644
--- a/drivers/pci/hotplug/ibmphp_pci.c
+++ b/drivers/pci/hotplug/ibmphp_pci.c
@@ -1119,7 +1119,7 @@ static struct res_needed *scan_behind_bridge (struct pci_func *func, u8 busno)
                                 pci_bus_read_config_dword (ibmphp_pci_bus, devfn, PCI_CLASS_REVISION, &class);
 
                                 debug ("hdr_type behind the bridge is %x\n", hdr_type);
-                                if (hdr_type & PCI_HEADER_TYPE_BRIDGE) {
+                                if ((hdr_type & 0x7f) == PCI_HEADER_TYPE_BRIDGE) {
                                         err ("embedded bridges not supported for hot-plugging.\n");
                                         amount->not_correct = 1;
                                         return amount;
diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
index fba785e9df75..712392504ed9 100644
--- a/drivers/pci/pcie/aer/aerdrv_core.c
+++ b/drivers/pci/pcie/aer/aerdrv_core.c
@@ -246,7 +246,7 @@ static int report_error_detected(struct pci_dev *dev, void *data)
                 !dev->driver->err_handler ||
                 !dev->driver->err_handler->error_detected) {
                 if (result_data->state == pci_channel_io_frozen &&
-                        !(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE)) {
+                        dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
                         /*
                          * In case of fatal recovery, if one of down-
                          * stream device has no driver. We might be
@@ -269,7 +269,7 @@ static int report_error_detected(struct pci_dev *dev, void *data)
                  * without recovery.
                  */
 
-                if (!(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
+                if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
                         vote = PCI_ERS_RESULT_NO_AER_DRIVER;
                 else
                         vote = PCI_ERS_RESULT_NONE;
@@ -369,7 +369,7 @@ static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
         else
                 result_data.result = PCI_ERS_RESULT_RECOVERED;
 
-        if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
+        if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
                 /*
                  * If the error is reported by a bridge, we think this error
                  * is related to the downstream link of the bridge, so we
@@ -440,7 +440,7 @@ static pci_ers_result_t reset_link(struct pci_dev *dev)
         pci_ers_result_t status;
         struct pcie_port_service_driver *driver;
 
-        if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
+        if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
                 /* Reset this port for all subordinates */
                 udev = dev;
         } else {
@@ -660,7 +660,7 @@ static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
                         &info->mask);
                 if (!(info->status & ~info->mask))
                         return 0;
-        } else if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE ||
+        } else if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
                 info->severity == AER_NONFATAL) {
 
                 /* Link is still healthy for IO reads */