[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>

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 */

drivers/pci/hotplug/pciehp_core.c

@@ -39,7 +39,6 @@
 #include <linux/init.h>
 #include <asm/uaccess.h>
 #include "pciehp.h"
-#include "pciehprm.h"
 #include <linux/interrupt.h>
 
 /* Global variables */
@@ -381,6 +380,7 @@ static int pciehp_probe(struct pcie_device *dev, const struct pcie_port_service_
 	dbg("%s: DRV_thread pid = %d\n", __FUNCTION__, current->pid);
 
 	pdev = dev->port;
+	ctrl->pci_dev = pdev;
 
 	rc = pcie_init(ctrl, dev,
 		(php_intr_callback_t) pciehp_handle_attention_button,
@@ -392,8 +392,6 @@ static int pciehp_probe(struct pcie_device *dev, const struct pcie_port_service_
 		goto err_out_free_ctrl;
 	}
 
-	ctrl->pci_dev = pdev;
-
 	pci_set_drvdata(pdev, ctrl);
 
 	ctrl->pci_bus = kmalloc(sizeof(*ctrl->pci_bus), GFP_KERNEL);
@@ -609,18 +607,14 @@ static int __init pcied_init(void)
 	if (retval)
 		goto error_hpc_init;
 
-	retval = pciehprm_init(PCI);
-	if (!retval) {
- 		retval = pcie_port_service_register(&hpdriver_portdrv);
- 		dbg("pcie_port_service_register = %d\n", retval);
-  		info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
- 		if (retval)
- 		   dbg("%s: Failure to register service\n", __FUNCTION__);
-	}
+	retval = pcie_port_service_register(&hpdriver_portdrv);
+ 	dbg("pcie_port_service_register = %d\n", retval);
+  	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
+ 	if (retval)
+		dbg("%s: Failure to register service\n", __FUNCTION__);
 
 error_hpc_init:
 	if (retval) {
-		pciehprm_cleanup();
 		pciehp_event_stop_thread();
 	};
 
@@ -632,8 +626,6 @@ static void __exit pcied_cleanup(void)
 	dbg("unload_pciehpd()\n");
 	unload_pciehpd();
 
-	pciehprm_cleanup();
-
 	dbg("pcie_port_service_unregister\n");
 	pcie_port_service_unregister(&hpdriver_portdrv);
 

drivers/pci/hotplug/pciehp_ctrl.c

@@ -40,7 +40,6 @@
 #include <linux/pci.h>
 #include "../pci.h"
 #include "pciehp.h"
-#include "pciehprm.h"
 
 static void interrupt_event_handler(struct controller *ctrl);
 

drivers/pci/hotplug/pciehp_hpc.c

@@ -1470,6 +1470,10 @@ int pcie_init(struct controller * ctrl,
 	}
 	dbg("%s: SLOT_STATUS offset %x writes slot_status %x\n", __FUNCTION__, SLOT_STATUS(ctrl->cap_base), temp_word);
 
+	rc = get_hp_hw_control_from_firmware(ctrl->pci_dev);
+	if (rc)
+		goto abort_free_ctlr;
+
 	/*  Add this HPC instance into the HPC list */
 	spin_lock(&list_lock);
 	if (php_ctlr_list_head == 0) {