[PATCH] pciehp: reduce dependence on ACPI

Reduce the PCI Express hotplug driver's dependence on ACPI.
We don't walk the acpi namespace anymore to build a list of
bridges and devices. We go to ACPI only to run the _OSC or
_OSHP methods to transition control of hotplug hardware from
system BIOS to the hotplug driver, and to run the _HPP
method to get hotplug device parameters like cache line size,
latency timer and SERR/PERR enable from BIOS.

Note that one of the side effects of this patch is that pciehp
does not automatically enable the hot-added device or its DMA
bus mastering capability now. It expects the device driver to
do that. This may break some drivers and we will have to fix
them as they are reported.

Signed-off-by: Rajesh Shah <rajesh.shah@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index e9480ddd5abf..e9c09566f851 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -49,6 +49,13 @@ extern int pciehp_debug;
 #define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME , ## arg)
 #define warn(format, arg...) printk(KERN_WARNING "%s: " format, MY_NAME , ## arg)
 
+struct hotplug_params {
+        u8 cache_line_size;
+        u8 latency_timer;
+        u8 enable_serr;
+        u8 enable_perr;
+};
+
 struct pci_func {
         struct pci_func *next;
         u8 bus;
@@ -199,6 +206,10 @@ extern int	pciehp_save_config	 	(struct controller *ctrl, int busnumber, int num
 extern int      pciehp_save_slot_config         (struct controller *ctrl, struct pci_func * new_slot);
 extern int      pciehp_configure_device         (struct slot *ctrl);
 extern int      pciehp_unconfigure_device       (struct pci_func* func);
+extern int      get_hp_hw_control_from_firmware(struct pci_dev *dev);
+extern void     get_hp_params_from_firmware(struct pci_dev *dev,
+                struct hotplug_params *hpp);
+
 
 
 /* Global variables */