c9ffa5a586
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: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
115 lines
3.0 KiB
C
115 lines
3.0 KiB
C
/*
|
|
* 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();
|
|
}
|