Commit c9ffa5a5 authored by Kenji Kaneshige's avatar Kenji Kaneshige Committed by Jesse Barnes

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
......@@ -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 \
......
......@@ -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 */
......
/*
* 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();
}
......@@ -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");
......
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