PCI: show dma_mask bits in /sys

So we can catch if the driver sets an incorrect dma_mask.

Reviewed-by: Grant Grundler <grundler@google.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 0fa707e2a0f8..c5df94e86678 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -184,6 +184,21 @@ numa_node_show(struct device *dev, struct device_attribute *attr, char *buf)
 #endif
 
 static ssize_t
+dma_mask_bits_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        return sprintf (buf, "%d\n", fls64(pdev->dma_mask));
+}
+
+static ssize_t
+consistent_dma_mask_bits_show(struct device *dev, struct device_attribute *attr,
+                                 char *buf)
+{
+        return sprintf (buf, "%d\n", fls64(dev->coherent_dma_mask));
+}
+
+static ssize_t
 msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
         struct pci_dev *pdev = to_pci_dev(dev);
@@ -314,6 +329,8 @@ struct device_attribute pci_dev_attrs[] = {
 #ifdef CONFIG_NUMA
         __ATTR_RO(numa_node),
 #endif
+        __ATTR_RO(dma_mask_bits),
+        __ATTR_RO(consistent_dma_mask_bits),
         __ATTR(enable, 0600, is_enabled_show, is_enabled_store),
         __ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
                 broken_parity_status_show,broken_parity_status_store),