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>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 3f3f691be2e7..92386fc4e82a 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -29,6 +29,7 @@ struct rtc_time;
 struct file;
 struct pci_controller;
 struct kimage;
+struct pci_host_bridge;
 
 struct machdep_calls {
         char            *name;
@@ -108,6 +109,8 @@ struct machdep_calls {
         void            (*pcibios_fixup)(void);
         int             (*pci_probe_mode)(struct pci_bus *);
         void            (*pci_irq_fixup)(struct pci_dev *dev);
+        int             (*pcibios_root_bridge_prepare)(struct pci_host_bridge
+                                *bridge);
 
         /* To setup PHBs when using automatic OF platform driver for PCI */
         int             (*pci_setup_phb)(struct pci_controller *host);