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    SubjectRe: [PATCH 4/4] ACPI PCI slot detection driver
    Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

    Thanks,
    Kenji Kaneshige


    Alex Chiang wrote:
    > Detect all physical PCI slots as described by ACPI, and create
    > entries in /sys/bus/pci/slots/.
    >
    > Not all physical slots are hotpluggable, and the acpiphp module
    > does not detect them. Now we know the physical PCI geography of
    > our system, without caring about hotplug.
    >
    > v10 -> v11:
    > Thanks to Kenji Kanishige for the following updates:
    > - Fix dmi table for Fujitsu PRIMEQUEST
    > - Fix _STA evaluation
    > - Use list_head for pci slot list
    > - Fix slot removal path
    >
    > v9 -> v10:
    > Allow an hp driver to override the pci_slot kobject name.
    >
    > v8 -> v9:
    > Add DMI quirk for Fujitsu machines; eval _STA before _SUN
    >
    > v6 -> v8:
    > No change
    >
    > v5 -> v6:
    > Add debugging information.
    >
    > v4 -> v5:
    > Convert to a tristate module.
    >
    > Remove #ifdef CONFIG_ACPI_PCI_SLOT, as struct pci_slot
    > objects are properly refcounted, and multiple calls to
    > pci_create/destroy_slot work just fine.
    >
    > Remove prior -EBUSY changes, as they have been folded
    > into the Introduce pci_slot patch.
    >
    > v3 -> v4:
    > Always attempt to call pci_create_slot from pcihp_core to
    > cover cases of
    > a) user did not say Y to Kconfig option ACPI_PCI_SLOT
    > b) native PCIe hotplug driver registering on a
    > non-ACPI system.
    >
    > Return -EBUSY if an hp driver attempts to register a slot
    > that is already registered to another driver. Do not
    > consider that to be an error condition in acpiphp and pciehp.
    >
    > v2 -> v3:
    > Add Kconfig option to driver, allowing users to [de]config
    > this driver. If configured, take slightly different code
    > paths in pci_hp_register and pci_hp_deregister.
    >
    > v1 -> v2:
    > Now recursively discovering p2p bridges and slots
    > underneath them. Hopefully, this will prevent us
    > from trying to register the same slot multiple times.
    >
    > Signed-off-by: Alex Chiang <achiang@hp.com>
    > ---
    > drivers/acpi/Kconfig | 9 +
    > drivers/acpi/Makefile | 1 +
    > drivers/acpi/pci_slot.c | 370 ++++++++++++++++++++++++++++++++
    > drivers/pci/hotplug/pci_hotplug_core.c | 16 ++
    > drivers/pci/hotplug/pciehp_core.c | 2 +-
    > drivers/pci/hotplug/sgi_hotplug.c | 2 +-
    > 6 files changed, 398 insertions(+), 2 deletions(-)
    > create mode 100644 drivers/acpi/pci_slot.c
    >
    > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
    > index b4f5e85..4ccb0e7 100644
    > --- a/drivers/acpi/Kconfig
    > +++ b/drivers/acpi/Kconfig
    > @@ -335,6 +335,15 @@ config ACPI_EC
    > the battery and thermal drivers. If you are compiling for a
    > mobile system, say Y.
    >
    > +config ACPI_PCI_SLOT
    > + tristate "PCI slot detection driver"
    > + default n
    > + help
    > + This driver will attempt to discover all PCI slots in your system,
    > + and creates entries in /sys/bus/pci/slots/. This feature can
    > + help you correlate PCI bus addresses with the physical geography
    > + of your slots. If you are unsure, say N.
    > +
    > config ACPI_POWER
    > bool
    > default y
    > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
    > index 40b0fca..579c29c 100644
    > --- a/drivers/acpi/Makefile
    > +++ b/drivers/acpi/Makefile
    > @@ -48,6 +48,7 @@ obj-$(CONFIG_ACPI_DOCK) += dock.o
    > obj-$(CONFIG_ACPI_BAY) += bay.o
    > obj-$(CONFIG_ACPI_VIDEO) += video.o
    > obj-y += pci_root.o pci_link.o pci_irq.o pci_bind.o
    > +obj-$(CONFIG_ACPI_PCI_SLOT) += pci_slot.o
    > obj-$(CONFIG_ACPI_POWER) += power.o
    > obj-$(CONFIG_ACPI_PROCESSOR) += processor.o
    > obj-$(CONFIG_ACPI_CONTAINER) += container.o
    > diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c
    > new file mode 100644
    > index 0000000..2b48ea7
    > --- /dev/null
    > +++ b/drivers/acpi/pci_slot.c
    > @@ -0,0 +1,370 @@
    > +/*
    > + * 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 Alex Chiang <achiang@hp.com>
    > + * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
    > + *
    > + * 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)
    > +
    > +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, int *device, unsigned long *sun)
    > +{
    > + int retval = 0;
    > + 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)) {
    > + retval = -1;
    > + 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);
    > + retval = -1;
    > + goto out;
    > + }
    > +
    > + *device = (adr >> 16) & 0xffff;
    > +
    > + /* 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);
    > + retval = -1;
    > + goto out;
    > + }
    > +
    > +out:
    > + kfree(buffer.pointer);
    > + return retval;
    > +}
    > +
    > +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[KOBJ_NAME_LEN];
    > + 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;
    > +
    > + if (check_slot(handle, &device, &sun))
    > + 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);
    > + }
    > +
    > + 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: %#lx, pci_bus: %x, device: %d, name: %s\n",
    > + (uint64_t)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;
    > +}
    > +
    > +#define ACPI_STA_FUNCTIONING (0x00000008)
    > +
    > +/*
    > + * 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_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);
    > +}
    > +
    > +#ifdef CONFIG_DMI
    > +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"),
    > + },
    > + },
    > + {}
    > +};
    > +#endif /* CONFIG_DMI */
    > +
    > +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);
    > diff --git a/drivers/pci/hotplug/pci_hotplug_core.c b/drivers/pci/hotplug/pci_hotplug_core.c
    > index 5208786..8181bf6 100644
    > --- a/drivers/pci/hotplug/pci_hotplug_core.c
    > +++ b/drivers/pci/hotplug/pci_hotplug_core.c
    > @@ -566,6 +566,11 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr)
    > return -EINVAL;
    > }
    >
    > + /*
    > + * No problems if we call this interface from both ACPI_PCI_SLOT
    > + * driver and call it here again. If we've already created the
    > + * pci_slot, the interface will simply bump the refcount.
    > + */
    > pci_slot = pci_create_slot(bus, slot_nr, slot->name);
    > if (IS_ERR(pci_slot))
    > return PTR_ERR(pci_slot);
    > @@ -579,6 +584,17 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr)
    > slot->pci_slot = pci_slot;
    > pci_slot->hotplug = slot;
    >
    > + /*
    > + * Allow pcihp drivers to override the ACPI_PCI_SLOT name.
    > + */
    > + if (strcmp(kobject_name(&pci_slot->kobj), slot->name)) {
    > + result = kobject_rename(&pci_slot->kobj, slot->name);
    > + if (result) {
    > + pci_destroy_slot(pci_slot);
    > + return result;
    > + }
    > + }
    > +
    > spin_lock(&pci_hotplug_slot_list_lock);
    > list_add(&slot->slot_list, &pci_hotplug_slot_list);
    > spin_unlock(&pci_hotplug_slot_list_lock);
    > diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
    > index e6d3d4d..7561d17 100644
    > --- a/drivers/pci/hotplug/pciehp_core.c
    > +++ b/drivers/pci/hotplug/pciehp_core.c
    > @@ -249,7 +249,7 @@ static int init_slots(struct controller *ctrl)
    > if (retval == -EBUSY)
    > goto error_info;
    > if (retval) {
    > - err ("pci_hp_register failed with error %d\n", retval);
    > + err("pci_hp_register failed with error %d\n", retval);
    > goto error_info;
    > }
    > /* create additional sysfs entries */
    > diff --git a/drivers/pci/hotplug/sgi_hotplug.c b/drivers/pci/hotplug/sgi_hotplug.c
    > index 8908834..5fd6887 100644
    > --- a/drivers/pci/hotplug/sgi_hotplug.c
    > +++ b/drivers/pci/hotplug/sgi_hotplug.c
    > @@ -668,7 +668,7 @@ static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
    >
    > register_err:
    > dev_dbg(&pci_bus->self->dev, "bus failed to register with err = %d\n",
    > - rc);
    > + rc);
    >
    > alloc_err:
    > if (rc == -ENOMEM)




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