/* * pci_slot.c - ACPI PCI Slot Driver * * The code here is heavily leveraged from the acpiphp module. * Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance. * Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code * review and fixes. * * Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P. * Alex Chiang <achiang@hp.com> * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * 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. 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., * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/types.h> #include <linux/pci.h> #include <linux/acpi.h> #include <acpi/acpi_bus.h> #include <acpi/acpi_drivers.h> #include <linux/dmi.h> static bool debug; static int check_sta_before_sun; #define DRIVER_VERSION "0.1" #define DRIVER_AUTHOR "Alex Chiang <achiang@hp.com>" #define DRIVER_DESC "ACPI PCI Slot Detection Driver" MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL"); MODULE_PARM_DESC(debug, "Debugging mode enabled or not"); module_param(debug, bool, 0644); #define _COMPONENT ACPI_PCI_COMPONENT ACPI_MODULE_NAME("pci_slot"); #define MY_NAME "pci_slot" #define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg) #define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg) #define dbg(format, arg...) \ do { \ if (debug) \ printk(KERN_DEBUG "%s: " format, \ MY_NAME , ## arg); \ } while (0) #define SLOT_NAME_SIZE 21 /* Inspired by #define in acpiphp.h */ struct acpi_pci_slot { acpi_handle root_handle; /* handle of the root bridge */ struct pci_slot *pci_slot; /* corresponding pci_slot */ struct list_head list; /* node in the list of slots */ }; static int acpi_pci_slot_add(acpi_handle handle); static void acpi_pci_slot_remove(acpi_handle handle); static LIST_HEAD(slot_list); static DEFINE_MUTEX(slot_list_lock); static struct acpi_pci_driver acpi_pci_slot_driver = { .add = acpi_pci_slot_add, .remove = acpi_pci_slot_remove, }; static int check_slot(acpi_handle handle, unsigned long long *sun) { int device = -1; unsigned long long adr, sta; acpi_status status; struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); dbg("Checking slot on path: %s\n", (char *)buffer.pointer); if (check_sta_before_sun) { /* If SxFy doesn't have _STA, we just assume it's there */ status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) goto out; } status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr); if (ACPI_FAILURE(status)) { dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer); goto out; } /* No _SUN == not a slot == bail */ status = acpi_evaluate_integer(handle, "_SUN", NULL, sun); if (ACPI_FAILURE(status)) { dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer); goto out; } device = (adr >> 16) & 0xffff; out: kfree(buffer.pointer); return device; } struct callback_args { acpi_walk_callback user_function; /* only for walk_p2p_bridge */ struct pci_bus *pci_bus; acpi_handle root_handle; }; /* * register_slot * * Called once for each SxFy object in the namespace. Don't worry about * calling pci_create_slot multiple times for the same pci_bus:device, * since each subsequent call simply bumps the refcount on the pci_slot. * * The number of calls to pci_destroy_slot from unregister_slot is * symmetrical. */ static acpi_status register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) { int device; unsigned long long sun; char name[SLOT_NAME_SIZE]; struct acpi_pci_slot *slot; struct pci_slot *pci_slot; struct callback_args *parent_context = context; struct pci_bus *pci_bus = parent_context->pci_bus; device = check_slot(handle, &sun); if (device < 0) return AE_OK; slot = kmalloc(sizeof(*slot), GFP_KERNEL); if (!slot) { err("%s: cannot allocate memory\n", __func__); return AE_OK; } snprintf(name, sizeof(name), "%llu", sun); pci_slot = pci_create_slot(pci_bus, device, name, NULL); if (IS_ERR(pci_slot)) { err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot)); kfree(slot); return AE_OK; } slot->root_handle = parent_context->root_handle; slot->pci_slot = pci_slot; INIT_LIST_HEAD(&slot->list); mutex_lock(&slot_list_lock); list_add(&slot->list, &slot_list); mutex_unlock(&slot_list_lock); get_device(&pci_bus->dev); dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n", pci_slot, pci_bus->number, device, name); return AE_OK; } /* * walk_p2p_bridge - discover and walk p2p bridges * @handle: points to an acpi_pci_root * @context: p2p_bridge_context pointer * * Note that when we call ourselves recursively, we pass a different * value of pci_bus in the child_context. */ static acpi_status walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv) { int device, function; unsigned long long adr; acpi_status status; acpi_handle dummy_handle; acpi_walk_callback user_function; struct pci_dev *dev; struct pci_bus *pci_bus; struct callback_args child_context; struct callback_args *parent_context = context; pci_bus = parent_context->pci_bus; user_function = parent_context->user_function; status = acpi_get_handle(handle, "_ADR", &dummy_handle); if (ACPI_FAILURE(status)) return AE_OK; status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr); if (ACPI_FAILURE(status)) return AE_OK; device = (adr >> 16) & 0xffff; function = adr & 0xffff; dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function)); if (!dev || !dev->subordinate) goto out; child_context.pci_bus = dev->subordinate; child_context.user_function = user_function; child_context.root_handle = parent_context->root_handle; dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number); status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, user_function, NULL, &child_context, NULL); if (ACPI_FAILURE(status)) goto out; status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, walk_p2p_bridge, NULL, &child_context, NULL); out: pci_dev_put(dev); return AE_OK; } /* * walk_root_bridge - generic root bridge walker * @handle: points to an acpi_pci_root * @user_function: user callback for slot objects * * Call user_function for all objects underneath this root bridge. * Walk p2p bridges underneath us and call user_function on those too. */ static int walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function) { int seg, bus; unsigned long long tmp; acpi_status status; acpi_handle dummy_handle; struct pci_bus *pci_bus; struct callback_args context; /* If the bridge doesn't have _STA, we assume it is always there */ status = acpi_get_handle(handle, "_STA", &dummy_handle); if (ACPI_SUCCESS(status)) { status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp); if (ACPI_FAILURE(status)) { info("%s: _STA evaluation failure\n", __func__); return 0; } if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0) /* don't register this object */ return 0; } status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp); seg = ACPI_SUCCESS(status) ? tmp : 0; status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp); bus = ACPI_SUCCESS(status) ? tmp : 0; pci_bus = pci_find_bus(seg, bus); if (!pci_bus) return 0; context.pci_bus = pci_bus; context.user_function = user_function; context.root_handle = handle; dbg("root bridge walk, pci_bus = %x\n", pci_bus->number); status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, user_function, NULL, &context, NULL); if (ACPI_FAILURE(status)) return status; status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, walk_p2p_bridge, NULL, &context, NULL); if (ACPI_FAILURE(status)) err("%s: walk_p2p_bridge failure - %d\n", __func__, status); return status; } /* * acpi_pci_slot_add * @handle: points to an acpi_pci_root */ static int acpi_pci_slot_add(acpi_handle handle) { acpi_status status; status = walk_root_bridge(handle, register_slot); if (ACPI_FAILURE(status)) err("%s: register_slot failure - %d\n", __func__, status); return status; } /* * acpi_pci_slot_remove * @handle: points to an acpi_pci_root */ static void acpi_pci_slot_remove(acpi_handle handle) { struct acpi_pci_slot *slot, *tmp; struct pci_bus *pbus; mutex_lock(&slot_list_lock); list_for_each_entry_safe(slot, tmp, &slot_list, list) { if (slot->root_handle == handle) { list_del(&slot->list); pbus = slot->pci_slot->bus; pci_destroy_slot(slot->pci_slot); put_device(&pbus->dev); kfree(slot); } } mutex_unlock(&slot_list_lock); } static int do_sta_before_sun(const struct dmi_system_id *d) { info("%s detected: will evaluate _STA before calling _SUN\n", d->ident); check_sta_before_sun = 1; return 0; } static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = { /* * Fujitsu Primequest machines will return 1023 to indicate an * error if the _SUN method is evaluated on SxFy objects that * are not present (as indicated by _STA), so for those machines, * we want to check _STA before evaluating _SUN. */ { .callback = do_sta_before_sun, .ident = "Fujitsu PRIMEQUEST", .matches = { DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"), DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"), }, }, {} }; static int __init acpi_pci_slot_init(void) { dmi_check_system(acpi_pci_slot_dmi_table); acpi_pci_register_driver(&acpi_pci_slot_driver); return 0; } static void __exit acpi_pci_slot_exit(void) { acpi_pci_unregister_driver(&acpi_pci_slot_driver); } module_init(acpi_pci_slot_init); module_exit(acpi_pci_slot_exit);