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authorKleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>2013-05-03 12:43:12 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-05-06 09:25:38 +1000
commitd82fb31abc46620b7c22758c75707069f2763646 (patch)
tree29a92372ff460db1008565aa027a7fc60f2277e9 /arch/powerpc/platforms/pseries/pci.c
parente61133dda480062d221f09e4fc18f66763f8ecd0 (diff)
downloadlinux-linaro-stable-d82fb31abc46620b7c22758c75707069f2763646.tar.gz
powerpc/pseries: Perform proper max_bus_speed detection
On pseries machines the detection for max_bus_speed should be done through an OpenFirmware property. This patch adds a function to perform this detection and a hook to perform dynamic adding of the function only for pseries. This is done by overwriting the weak pcibios_root_bridge_prepare function which is called by pci_create_root_bus(). From: Lucas Kannebley Tavares <lucaskt@linux.vnet.ibm.com> Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/pseries/pci.c')
-rw-r--r--arch/powerpc/platforms/pseries/pci.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c
index 0b580f413a9a..5f93856cdf47 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c
@@ -108,3 +108,56 @@ static void fixup_winbond_82c105(struct pci_dev* dev)
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_82C105,
fixup_winbond_82c105);
+
+int pseries_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+ struct device_node *dn, *pdn;
+ struct pci_bus *bus;
+ const uint32_t *pcie_link_speed_stats;
+
+ bus = bridge->bus;
+
+ dn = pcibios_get_phb_of_node(bus);
+ if (!dn)
+ return 0;
+
+ for (pdn = dn; pdn != NULL; pdn = of_get_next_parent(pdn)) {
+ pcie_link_speed_stats = (const uint32_t *) of_get_property(pdn,
+ "ibm,pcie-link-speed-stats", NULL);
+ if (pcie_link_speed_stats)
+ break;
+ }
+
+ of_node_put(pdn);
+
+ if (!pcie_link_speed_stats) {
+ pr_err("no ibm,pcie-link-speed-stats property\n");
+ return 0;
+ }
+
+ switch (pcie_link_speed_stats[0]) {
+ case 0x01:
+ bus->max_bus_speed = PCIE_SPEED_2_5GT;
+ break;
+ case 0x02:
+ bus->max_bus_speed = PCIE_SPEED_5_0GT;
+ break;
+ default:
+ bus->max_bus_speed = PCI_SPEED_UNKNOWN;
+ break;
+ }
+
+ switch (pcie_link_speed_stats[1]) {
+ case 0x01:
+ bus->cur_bus_speed = PCIE_SPEED_2_5GT;
+ break;
+ case 0x02:
+ bus->cur_bus_speed = PCIE_SPEED_5_0GT;
+ break;
+ default:
+ bus->cur_bus_speed = PCI_SPEED_UNKNOWN;
+ break;
+ }
+
+ return 0;
+}