aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/pci/pci.c6
-rw-r--r--drivers/pci/probe.c14
-rw-r--r--include/linux/pci.h3
3 files changed, 20 insertions, 3 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4e84fd4a4312..e9651f0a8817 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -77,7 +77,7 @@ 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_SAFE;
+enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF;
/*
* The default CLS is used if arch didn't set CLS explicitly and not
@@ -3568,10 +3568,14 @@ 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_tune_off", 17)) {
+ pcie_bus_config = PCIE_BUS_TUNE_OFF;
} 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 if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
+ pcie_bus_config = PCIE_BUS_PEER2PEER;
} else {
printk(KERN_ERR "PCI: Unknown option `%s'\n",
str);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index f3f94a5c068f..6ab6bd3df4b2 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1458,12 +1458,24 @@ static int pcie_bus_configure_set(struct pci_dev *dev, void *data)
*/
void pcie_bus_configure_settings(struct pci_bus *bus, u8 mpss)
{
- u8 smpss = mpss;
+ u8 smpss;
if (!pci_is_pcie(bus->self))
return;
+ if (pcie_bus_config == PCIE_BUS_TUNE_OFF)
+ return;
+
+ /* FIXME - Peer to peer DMA is possible, though the endpoint would need
+ * to be aware to the MPS of the destination. To work around this,
+ * simply force the MPS of the entire system to the smallest possible.
+ */
+ if (pcie_bus_config == PCIE_BUS_PEER2PEER)
+ smpss = 0;
+
if (pcie_bus_config == PCIE_BUS_SAFE) {
+ smpss = mpss;
+
pcie_find_smpss(bus->self, &smpss);
pci_walk_bus(bus, pcie_find_smpss, &smpss);
}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8c230cbcbb48..9fc01226055b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -621,8 +621,9 @@ struct pci_driver {
extern void pcie_bus_configure_settings(struct pci_bus *bus, u8 smpss);
enum pcie_bus_config_types {
- PCIE_BUS_PERFORMANCE,
+ PCIE_BUS_TUNE_OFF,
PCIE_BUS_SAFE,
+ PCIE_BUS_PERFORMANCE,
PCIE_BUS_PEER2PEER,
};