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@xxxxxxxxxxxxxx> --- drivers/pci/hotplug/Makefile | 3 + drivers/pci/hotplug/pciehp.h | 15 ++++- drivers/pci/hotplug/pciehp_acpi.c | 114 ++++++++++++++++++++++++++++++++++++++ drivers/pci/hotplug/pciehp_core.c | 1 4 files changed, 132 insertions(+), 1 deletion(-) Index: 20081217/drivers/pci/hotplug/pciehp.h =================================================================== --- 20081217.orig/drivers/pci/hotplug/pciehp.h +++ 20081217/drivers/pci/hotplug/pciehp.h @@ -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_f 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 */ Index: 20081217/drivers/pci/hotplug/pciehp_acpi.c =================================================================== --- /dev/null +++ 20081217/drivers/pci/hotplug/pciehp_acpi.c @@ -0,0 +1,114 @@ +/* + * 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(); +} Index: 20081217/drivers/pci/hotplug/Makefile =================================================================== --- 20081217.orig/drivers/pci/hotplug/Makefile +++ 20081217/drivers/pci/hotplug/Makefile @@ -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 \ Index: 20081217/drivers/pci/hotplug/pciehp_core.c =================================================================== --- 20081217.orig/drivers/pci/hotplug/pciehp_core.c +++ 20081217/drivers/pci/hotplug/pciehp_core.c @@ -521,6 +521,7 @@ 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"); -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html