diff options
Diffstat (limited to 'kernel/drivers/pci/hotplug/pciehp_acpi.c')
| -rw-r--r-- | kernel/drivers/pci/hotplug/pciehp_acpi.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/kernel/drivers/pci/hotplug/pciehp_acpi.c b/kernel/drivers/pci/hotplug/pciehp_acpi.c new file mode 100644 index 000000000..93cc9266e --- /dev/null +++ b/kernel/drivers/pci/hotplug/pciehp_acpi.c @@ -0,0 +1,137 @@ +/* + * 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 <linux/pci.h> +#include <linux/pci_hotplug.h> +#include <linux/slab.h> +#include <linux/module.h> +#include "pciehp.h" + +#define PCIEHP_DETECT_PCIE (0) +#define PCIEHP_DETECT_ACPI (1) +#define PCIEHP_DETECT_AUTO (2) +#define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_AUTO + +struct dummy_slot { + u32 number; + struct list_head list; +}; + +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, auto\n" + " pcie - Use PCIe based slot detection\n" + " acpi - Use ACPI for slot detection\n" + " auto(default) - Auto select mode. Use acpi option if duplicate\n" + " slot ids are found. Otherwise, use pcie option\n"); + +int pciehp_acpi_slot_detection_check(struct pci_dev *dev) +{ + if (slot_detection_mode != PCIEHP_DETECT_ACPI) + return 0; + if (acpi_pci_detect_ejectable(ACPI_HANDLE(&dev->dev))) + 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; + if (!strcmp(pciehp_detect_mode, "auto")) + return PCIEHP_DETECT_AUTO; + warn("bad specifier '%s' for pciehp_detect_mode. Use default\n", + pciehp_detect_mode); + return PCIEHP_DETECT_DEFAULT; +} + +static int __initdata dup_slot_id; +static int __initdata acpi_slot_detected; +static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots); + +/* Dummy driver for duplicate name detection */ +static int __init dummy_probe(struct pcie_device *dev) +{ + u32 slot_cap; + acpi_handle handle; + struct dummy_slot *slot, *tmp; + struct pci_dev *pdev = dev->port; + + pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap); + slot = kzalloc(sizeof(*slot), GFP_KERNEL); + if (!slot) + return -ENOMEM; + slot->number = (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19; + list_for_each_entry(tmp, &dummy_slots, list) { + if (tmp->number == slot->number) + dup_slot_id++; + } + list_add_tail(&slot->list, &dummy_slots); + handle = ACPI_HANDLE(&pdev->dev); + if (!acpi_slot_detected && acpi_pci_detect_ejectable(handle)) + acpi_slot_detected = 1; + return -ENODEV; /* dummy driver always returns error */ +} + +static struct pcie_port_service_driver __initdata dummy_driver = { + .name = "pciehp_dummy", + .port_type = PCIE_ANY_PORT, + .service = PCIE_PORT_SERVICE_HP, + .probe = dummy_probe, +}; + +static int __init select_detection_mode(void) +{ + struct dummy_slot *slot, *tmp; + + if (pcie_port_service_register(&dummy_driver)) + return PCIEHP_DETECT_ACPI; + pcie_port_service_unregister(&dummy_driver); + list_for_each_entry_safe(slot, tmp, &dummy_slots, list) { + list_del(&slot->list); + kfree(slot); + } + if (acpi_slot_detected && dup_slot_id) + return PCIEHP_DETECT_ACPI; + return PCIEHP_DETECT_PCIE; +} + +void __init pciehp_acpi_slot_detection_init(void) +{ + slot_detection_mode = parse_detect_mode(); + if (slot_detection_mode != PCIEHP_DETECT_AUTO) + goto out; + slot_detection_mode = select_detection_mode(); +out: + if (slot_detection_mode == PCIEHP_DETECT_ACPI) + info("Using ACPI for slot detection.\n"); +} |