drivers/pci/hotplug/acpi_pcihp.c - kernel/bruno - Git at Google

 /*
  * Common ACPI functions for hot plug platforms
  *
  * Copyright (C) 2006 Intel Corporation
  *
  * All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or (at
  * your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  * NON INFRINGEMENT.  See the GNU General Public License for more
  * details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
  * Send feedback to <kristen.c.accardi@intel.com>
  *
  */

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/pci.h>
 #include <linux/pci_hotplug.h>
 #include <linux/acpi.h>
 #include <linux/pci-acpi.h>
 #include <linux/slab.h>

 #define MY_NAME	"acpi_pcihp"

 #define dbg(fmt, arg...) do { if (debug_acpi) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __func__ , ## arg); } while (0)
 #define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
 #define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
 #define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)

 #define	METHOD_NAME__SUN	"_SUN"
 #define	METHOD_NAME_OSHP	"OSHP"

 static bool debug_acpi;

 /* acpi_run_oshp - get control of hotplug from the firmware
  *
  * @handle - the handle of the hotplug controller.
  */
 static acpi_status acpi_run_oshp(acpi_handle handle)
 {
 	acpi_status		status;
 	struct acpi_buffer	string = { ACPI_ALLOCATE_BUFFER, NULL };

 	acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);

 	/* run OSHP */
 	status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
 	if (ACPI_FAILURE(status))
 		if (status != AE_NOT_FOUND)
 			printk(KERN_ERR "%s:%s OSHP fails=0x%x\n",
 			       __func__, (char *)string.pointer, status);
 		else
 			dbg("%s:%s OSHP not found\n",
 			    __func__, (char *)string.pointer);
 	else
 		pr_debug("%s:%s OSHP passes\n", __func__,
 			(char *)string.pointer);

 	kfree(string.pointer);
 	return status;
 }

 /**
  * acpi_get_hp_hw_control_from_firmware
  * @dev: the pci_dev of the bridge that has a hotplug controller
  * @flags: requested control bits for _OSC
  *
  * Attempt to take hotplug control from firmware.
  */
 int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
 {
 	acpi_status status;
 	acpi_handle chandle, handle;
 	struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };

 	flags &= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
 	if (!flags) {
 		err("Invalid flags %u specified!\n", flags);
 		return -EINVAL;
 	}

 	/*
 	 * Per PCI firmware specification, we should run the ACPI _OSC
 	 * method to get control of hotplug hardware before using it. If
 	 * an _OSC is missing, we look for an OSHP to do the same thing.
 	 * To handle different BIOS behavior, we look for _OSC on a root
 	 * bridge preferentially (according to PCI fw spec). Later for
 	 * OSHP within the scope of the hotplug controller and its parents,
 	 * up to the host bridge under which this controller exists.
 	 */
 	handle = acpi_find_root_bridge_handle(pdev);
 	if (handle) {
 		acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
 		dbg("Trying to get hotplug control for %s\n",
 				(char *)string.pointer);
 		status = acpi_pci_osc_control_set(handle, &flags, flags);
 		if (ACPI_SUCCESS(status))
 			goto got_one;
 		if (status == AE_SUPPORT)
 			goto no_control;
 		kfree(string.pointer);
 		string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
 	}

 	handle = ACPI_HANDLE(&pdev->dev);
 	if (!handle) {
 		/*
 		 * This hotplug controller was not listed in the ACPI name
 		 * space at all. Try to get acpi handle of parent pci bus.
 		 */
 		struct pci_bus *pbus;
 		for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
 			handle = acpi_pci_get_bridge_handle(pbus);
 			if (handle)
 				break;
 		}
 	}

 	while (handle) {
 		acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
 		dbg("Trying to get hotplug control for %s \n",
 		    (char *)string.pointer);
 		status = acpi_run_oshp(handle);
 		if (ACPI_SUCCESS(status))
 			goto got_one;
 		if (acpi_is_root_bridge(handle))
 			break;
 		chandle = handle;
 		status = acpi_get_parent(chandle, &handle);
 		if (ACPI_FAILURE(status))
 			break;
 	}
 no_control:
 	dbg("Cannot get control of hotplug hardware for pci %s\n",
 	    pci_name(pdev));
 	kfree(string.pointer);
 	return -ENODEV;
 got_one:
 	dbg("Gained control for hotplug HW for pci %s (%s)\n",
 	    pci_name(pdev), (char *)string.pointer);
 	kfree(string.pointer);
 	return 0;
 }
 EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);

 static int pcihp_is_ejectable(acpi_handle handle)
 {
 	acpi_status status;
 	unsigned long long removable;
 	if (!acpi_has_method(handle, "_ADR"))
 		return 0;
 	if (acpi_has_method(handle, "_EJ0"))
 		return 1;
 	status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
 	if (ACPI_SUCCESS(status) && removable)
 		return 1;
 	return 0;
 }

 /**
  * acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
  * @pbus: the PCI bus of the PCI slot corresponding to 'handle'
  * @handle: ACPI handle to check
  *
  * Return 1 if handle is ejectable PCI slot, 0 otherwise.
  */
 int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
 {
 	acpi_handle bridge_handle, parent_handle;

 	bridge_handle = acpi_pci_get_bridge_handle(pbus);
 	if (!bridge_handle)
 		return 0;
 	if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
 		return 0;
 	if (bridge_handle != parent_handle)
 		return 0;
 	return pcihp_is_ejectable(handle);
 }
 EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable);

 static acpi_status
 check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
 	int *found = (int *)context;
 	if (pcihp_is_ejectable(handle)) {
 		*found = 1;
 		return AE_CTRL_TERMINATE;
 	}
 	return AE_OK;
 }

 /**
  * acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
  * @handle - handle of the PCI bus to scan
  *
  * Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
  */
 int acpi_pci_detect_ejectable(acpi_handle handle)
 {
 	int found = 0;

 	if (!handle)
 		return found;

 	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 			    check_hotplug, NULL, (void *)&found, NULL);
 	return found;
 }
 EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable);

 module_param(debug_acpi, bool, 0644);
 MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not");
	/*
	* Common ACPI functions for hot plug platforms
	*
	* Copyright (C) 2006 Intel Corporation
	*
	* All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or (at
	* your option) any later version.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	* NON INFRINGEMENT. See the GNU General Public License for more
	* details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*
	* Send feedback to <kristen.c.accardi@intel.com>
	*
	*/

	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/pci.h>
	#include <linux/pci_hotplug.h>
	#include <linux/acpi.h>
	#include <linux/pci-acpi.h>
	#include <linux/slab.h>

	#define MY_NAME "acpi_pcihp"

	#define dbg(fmt, arg...) do { if (debug_acpi) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __func__ , ## arg); } while (0)
	#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
	#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
	#define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)

	#define METHOD_NAME__SUN "_SUN"
	#define METHOD_NAME_OSHP "OSHP"

	static bool debug_acpi;

	/* acpi_run_oshp - get control of hotplug from the firmware
	*
	* @handle - the handle of the hotplug controller.
	*/
	static acpi_status acpi_run_oshp(acpi_handle handle)
	{
	acpi_status status;
	struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };

	acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);

	/* run OSHP */
	status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
	if (ACPI_FAILURE(status))
	if (status != AE_NOT_FOUND)
	printk(KERN_ERR "%s:%s OSHP fails=0x%x\n",
	__func__, (char *)string.pointer, status);
	else
	dbg("%s:%s OSHP not found\n",
	__func__, (char *)string.pointer);
	else
	pr_debug("%s:%s OSHP passes\n", __func__,
	(char *)string.pointer);

	kfree(string.pointer);
	return status;
	}

	/**
	* acpi_get_hp_hw_control_from_firmware
	* @dev: the pci_dev of the bridge that has a hotplug controller
	* @flags: requested control bits for _OSC
	*
	* Attempt to take hotplug control from firmware.
	*/
	int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
	{
	acpi_status status;
	acpi_handle chandle, handle;
	struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };

	flags &= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
	if (!flags) {
	err("Invalid flags %u specified!\n", flags);
	return -EINVAL;
	}

	/*
	* Per PCI firmware specification, we should run the ACPI _OSC
	* method to get control of hotplug hardware before using it. If
	* an _OSC is missing, we look for an OSHP to do the same thing.
	* To handle different BIOS behavior, we look for _OSC on a root
	* bridge preferentially (according to PCI fw spec). Later for
	* OSHP within the scope of the hotplug controller and its parents,
	* up to the host bridge under which this controller exists.
	*/
	handle = acpi_find_root_bridge_handle(pdev);
	if (handle) {
	acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
	dbg("Trying to get hotplug control for %s\n",
	(char *)string.pointer);
	status = acpi_pci_osc_control_set(handle, &flags, flags);
	if (ACPI_SUCCESS(status))
	goto got_one;
	if (status == AE_SUPPORT)
	goto no_control;
	kfree(string.pointer);
	string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
	}

	handle = ACPI_HANDLE(&pdev->dev);
	if (!handle) {
	/*
	* This hotplug controller was not listed in the ACPI name
	* space at all. Try to get acpi handle of parent pci bus.
	*/
	struct pci_bus *pbus;
	for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
	handle = acpi_pci_get_bridge_handle(pbus);
	if (handle)
	break;
	}
	}

	while (handle) {
	acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
	dbg("Trying to get hotplug control for %s \n",
	(char *)string.pointer);
	status = acpi_run_oshp(handle);
	if (ACPI_SUCCESS(status))
	goto got_one;
	if (acpi_is_root_bridge(handle))
	break;
	chandle = handle;
	status = acpi_get_parent(chandle, &handle);
	if (ACPI_FAILURE(status))
	break;
	}
	no_control:
	dbg("Cannot get control of hotplug hardware for pci %s\n",
	pci_name(pdev));
	kfree(string.pointer);
	return -ENODEV;
	got_one:
	dbg("Gained control for hotplug HW for pci %s (%s)\n",
	pci_name(pdev), (char *)string.pointer);
	kfree(string.pointer);
	return 0;
	}
	EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);

	static int pcihp_is_ejectable(acpi_handle handle)
	{
	acpi_status status;
	unsigned long long removable;
	if (!acpi_has_method(handle, "_ADR"))
	return 0;
	if (acpi_has_method(handle, "_EJ0"))
	return 1;
	status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
	if (ACPI_SUCCESS(status) && removable)
	return 1;
	return 0;
	}

	/**
	* acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
	* @pbus: the PCI bus of the PCI slot corresponding to 'handle'
	* @handle: ACPI handle to check
	*
	* Return 1 if handle is ejectable PCI slot, 0 otherwise.
	*/
	int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
	{
	acpi_handle bridge_handle, parent_handle;

	bridge_handle = acpi_pci_get_bridge_handle(pbus);
	if (!bridge_handle)
	return 0;
	if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
	return 0;
	if (bridge_handle != parent_handle)
	return 0;
	return pcihp_is_ejectable(handle);
	}
	EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable);

	static acpi_status
	check_hotplug(acpi_handle handle, u32 lvl, void context, void *rv)
	{
	int found = (int )context;
	if (pcihp_is_ejectable(handle)) {
	*found = 1;
	return AE_CTRL_TERMINATE;
	}
	return AE_OK;
	}

	/**
	* acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
	* @handle - handle of the PCI bus to scan
	*
	* Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
	*/
	int acpi_pci_detect_ejectable(acpi_handle handle)
	{
	int found = 0;

	if (!handle)
	return found;

	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
	check_hotplug, NULL, (void *)&found, NULL);
	return found;
	}
	EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable);

	module_param(debug_acpi, bool, 0644);
	MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not");