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Commit c9ffa5a5 authored by Kenji Kaneshige's avatar Kenji Kaneshige Committed by Jesse Barnes
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PCI: pciehp: add ACPI based slot detection 



There is a problem that some non hot-pluggable PCIe slots are detected
as hot-pluggable by pciehp on some platforms. The immediate cause of
this problem is that hot-plug capable bit in the Slot Capabilities
register is set even for non hot-pluggable slots on those platforms.
It seems a BIOS/hardware problem, but we need workaround about that.

Some of those platforms define hot-pluggable PCIe slots on ACPI
namespace properly, while hot-plug capable bit in the Slot
Capabilities register is set improperly. So using ACPI namespace
information in pciehp to detect PCIe hot-pluggable slots would be a
workaround.

This patch adds 'pciehp_detect_mode' module option. When 'acpi' is
specified, pciehp uses ACPI namespace information to detect PCIe
hot-pluggable slots.

Signed-off-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 873392ca

drivers/pci/hotplug/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -55,6 +55,9 @@ pciehp-objs := pciehp_core.o \ 
				pciehp_ctrl.o	\

				pciehp_pci.o	\

				pciehp_hpc.o

ifdef CONFIG_ACPI

pciehp-objs		+=	pciehp_acpi.o

endif



shpchp-objs		:=	shpchp_core.o	\

				shpchp_ctrl.o	\

drivers/pci/hotplug/pciehp.h

+14 −1
Original line number Diff line number Diff line
@@ -220,11 +220,23 @@ struct hpc_ops { 
#include <acpi/actypes.h>

#include <linux/pci-acpi.h>



extern void __init pciehp_acpi_slot_detection_init(void);

extern int pciehp_acpi_slot_detection_check(struct pci_dev *dev);



static inline void pciehp_firmware_init(void)

{

	pciehp_acpi_slot_detection_init();

}



static inline int pciehp_get_hp_hw_control_from_firmware(struct pci_dev *dev)

{

	int retval;

	u32 flags = (OSC_PCI_EXPRESS_NATIVE_HP_CONTROL |

		     OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);

	return acpi_get_hp_hw_control_from_firmware(dev, flags);

	retval = acpi_get_hp_hw_control_from_firmware(dev, flags);

	if (retval)

		return retval;

	return pciehp_acpi_slot_detection_check(dev);

}



static inline int pciehp_get_hp_params_from_firmware(struct pci_dev *dev,
@@ -235,6 +247,7 @@ static inline int pciehp_get_hp_params_from_firmware(struct pci_dev *dev, 
	return 0;

}

#else

#define pciehp_firmware_init()				do {} while (0)

#define pciehp_get_hp_hw_control_from_firmware(dev) 	0

#define pciehp_get_hp_params_from_firmware(dev, hpp)    (-ENODEV)

#endif 				/* CONFIG_ACPI */

drivers/pci/hotplug/pciehp_acpi.c

0 → 100644
+114 −0
Original line number Diff line number Diff line 
/*

 * ACPI related functions for PCI Express Hot Plug driver.

 *

 * Copyright (C) 2008 Kenji Kaneshige

 * Copyright (C) 2008 Fujitsu Limited.

 *

 * 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.

 *

 */



#include <linux/acpi.h>

#include "pciehp.h"



#define PCIEHP_DETECT_PCIE	(0)

#define PCIEHP_DETECT_ACPI	(1)

#define PCIEHP_DETECT_DEFAULT	PCIEHP_DETECT_PCIE



static int slot_detection_mode;

static char *pciehp_detect_mode;

module_param(pciehp_detect_mode, charp, 0444);

MODULE_PARM_DESC(pciehp_detect_mode,

		 "Slot detection mode: pcie, acpi\n"

		 "  pcie - Use PCIe based slot detection (default)\n"

		 "  acpi - Use ACPI for slot detection\n");



static int is_ejectable(acpi_handle handle)

{

	acpi_status status;

	acpi_handle tmp;

	unsigned long long removable;

	status = acpi_get_handle(handle, "_ADR", &tmp);

	if (ACPI_FAILURE(status))

		return 0;

	status = acpi_get_handle(handle, "_EJ0", &tmp);

	if (ACPI_SUCCESS(status))

		return 1;

	status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);

	if (ACPI_SUCCESS(status) && removable)

		return 1;

	return 0;

}



static acpi_status

check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)

{

	int *found = (int *)context;

	if (is_ejectable(handle)) {

		*found = 1;

		return AE_CTRL_TERMINATE;

	}

	return AE_OK;

}



static int pciehp_detect_acpi_slot(struct pci_bus *pbus)

{

	acpi_handle handle;

	struct pci_dev *pdev = pbus->self;

	int found = 0;



	if (!pdev){

		int seg = pci_domain_nr(pbus), busnr = pbus->number;

		handle = acpi_get_pci_rootbridge_handle(seg, busnr);

	} else

		handle = DEVICE_ACPI_HANDLE(&(pdev->dev));



	if (!handle)

		return 0;



	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,

			    check_hotplug, (void *)&found, NULL);

	return found;

}



int pciehp_acpi_slot_detection_check(struct pci_dev *dev)

{

	if (slot_detection_mode != PCIEHP_DETECT_ACPI)

		return 0;

	if (pciehp_detect_acpi_slot(dev->subordinate))

		return 0;

	return -ENODEV;

}



static int __init parse_detect_mode(void)

{

	if (!pciehp_detect_mode)

		return PCIEHP_DETECT_DEFAULT;

	if (!strcmp(pciehp_detect_mode, "pcie"))

		return PCIEHP_DETECT_PCIE;

	if (!strcmp(pciehp_detect_mode, "acpi"))

		return PCIEHP_DETECT_ACPI;

	warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",

	     pciehp_detect_mode);

	return PCIEHP_DETECT_DEFAULT;

}



void __init pciehp_acpi_slot_detection_init(void)

{

	slot_detection_mode = parse_detect_mode();

}

drivers/pci/hotplug/pciehp_core.c

+1 −0
Original line number Diff line number Diff line
@@ -522,6 +522,7 @@ static int __init pcied_init(void) 
{

	int retval = 0;



	pciehp_firmware_init();

	retval = pcie_port_service_register(&hpdriver_portdrv);

 	dbg("pcie_port_service_register = %d\n", retval);

  	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");