1 files changed, 67 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 08a95b369d85..0ce67423a0a3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -77,6 +77,8 @@ unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
 unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
 unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
 
+enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PERFORMANCE;
+
 /*
  * The default CLS is used if arch didn't set CLS explicitly and not
  * all pci devices agree on the same value.  Arch can override either
@@ -3223,6 +3225,67 @@ out:
 EXPORT_SYMBOL(pcie_set_readrq);
 
 /**
+ * pcie_get_mps - get PCI Express maximum payload size
+ * @dev: PCI device to query
+ *
+ * Returns maximum payload size in bytes
+ *    or appropriate error value.
+ */
+int pcie_get_mps(struct pci_dev *dev)
+{
+        int ret, cap;
+        u16 ctl;
+
+        cap = pci_pcie_cap(dev);
+        if (!cap)
+                return -EINVAL;
+
+        ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
+        if (!ret)
+                ret = 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
+
+        return ret;
+}
+
+/**
+ * pcie_set_mps - set PCI Express maximum payload size
+ * @dev: PCI device to query
+ * @mps: maximum payload size in bytes
+ *    valid values are 128, 256, 512, 1024, 2048, 4096
+ *
+ * If possible sets maximum payload size
+ */
+int pcie_set_mps(struct pci_dev *dev, int mps)
+{
+        int cap, err = -EINVAL;
+        u16 ctl, v;
+
+        if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
+                goto out;
+
+        v = ffs(mps) - 8;
+        if (v > dev->pcie_mpss) 
+                goto out;
+        v <<= 5;
+
+        cap = pci_pcie_cap(dev);
+        if (!cap)
+                goto out;
+
+        err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
+        if (err)
+                goto out;
+
+        if ((ctl & PCI_EXP_DEVCTL_PAYLOAD) != v) {
+                ctl &= ~PCI_EXP_DEVCTL_PAYLOAD;
+                ctl |= v;
+                err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl);
+        }
+out:
+        return err;
+}
+
+/**
  * pci_select_bars - Make BAR mask from the type of resource
  * @dev: the PCI device for which BAR mask is made
  * @flags: resource type mask to be selected
@@ -3505,6 +3568,10 @@ static int __init pci_setup(char *str)
                                 pci_hotplug_io_size = memparse(str + 9, &str);
                         } else if (!strncmp(str, "hpmemsize=", 10)) {
                                 pci_hotplug_mem_size = memparse(str + 10, &str);
+                        } else if (!strncmp(str, "pcie_bus_safe", 13)) {
+                                pcie_bus_config = PCIE_BUS_SAFE;
+                        } else if (!strncmp(str, "pcie_bus_perf", 13)) {
+                                pcie_bus_config = PCIE_BUS_PERFORMANCE;
                         } else {
                                 printk(KERN_ERR "PCI: Unknown option `%s'\n",
                                                 str);