/*
* 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/types.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
static int 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 20 /* 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 *sun)
{
int device = -1;
unsigned 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 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), "%u", (u32)sun);
pci_slot = pci_create_slot(pci_bus, device, name);
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);
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 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, &child_context, NULL);
if (ACPI_FAILURE(status))
goto out;
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
walk_p2p_bridge, &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 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, &context, NULL);
if (ACPI_FAILURE(status))
return status;
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
walk_p2p_bridge, &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;
mutex_lock(&slot_list_lock);
list_for_each_entry_safe(slot, tmp, &slot_list, list) {
if (slot->root_handle == handle) {
list_del(&slot->list);
pci_destroy_slot(slot->pci_slot);
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);
