[PATCH v8 09/13] PCI, ACPI: handle PCI slot devices when creating/destroying PCI busses

From: Jiang Liu
Date: Tue Feb 26 2013 - 10:32:15 EST


Currently the pci_slot driver doesn't update PCI slot devices when PCI
device hotplug event happens, which may cause memory leak and returning
stale information to user.

Now the pci_slot driver has been changed as built-in driver, so invoke
PCI slot enumeration and destroy routines directly from the PCI core.
And remove ACPI PCI sub-driver related code because it isn't needed
any more.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/acpi/internal.h | 5 --
drivers/acpi/pci_slot.c | 177 +++++++---------------------------------------
drivers/acpi/scan.c | 1 -
drivers/pci/pci-acpi.c | 7 +-
include/linux/pci-acpi.h | 12 ++++
5 files changed, 44 insertions(+), 158 deletions(-)

diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index e09ce03..0f24148 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -67,11 +67,6 @@ struct acpi_ec {

extern struct acpi_ec *first_ec;

-#ifdef CONFIG_ACPI_PCI_SLOT
-void acpi_pci_slot_init(void);
-#else
-static inline void acpi_pci_slot_init(void) { }
-#endif
int acpi_pci_root_init(void);
void acpi_pci_root_hp_init(void);
int acpi_ec_init(void);
diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c
index a7d7e77..35d7227 100644
--- a/drivers/acpi/pci_slot.c
+++ b/drivers/acpi/pci_slot.c
@@ -9,6 +9,9 @@
* Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P.
* Alex Chiang <achiang@xxxxxx>
*
+ * Copyright (C) 2013 Huawei Tech. Co., Ltd.
+ * Jiang Liu <jiang.liu@xxxxxxxxxx>
+ *
* 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.
@@ -28,10 +31,9 @@
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
+#include <linux/list.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;
@@ -50,32 +52,23 @@ module_param(debug, bool, 0644);
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 err(format, arg...) pr_err("%s: " format , MY_NAME , ## arg)
+#define info(format, arg...) pr_info("%s: " format , MY_NAME , ## arg)
#define dbg(format, arg...) \
do { \
if (debug) \
- printk(KERN_DEBUG "%s: " format, \
- MY_NAME , ## arg); \
+ pr_debug(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(struct acpi_pci_root *root);
-static void acpi_pci_slot_remove(struct acpi_pci_root *root);
-
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)
@@ -114,21 +107,8 @@ out:
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.
+ * Check whether handle has an associated slot and create PCI slot if it has.
*/
static acpi_status
register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
@@ -138,13 +118,22 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
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;
+ struct pci_bus *pci_bus = context;

device = check_slot(handle, &sun);
if (device < 0)
return AE_OK;

+ /*
+ * There may be multiple PCI functions associated with the same slot.
+ * Check whether PCI slot has already been created for this PCI device.
+ */
+ list_for_each_entry(slot, &slot_list, list) {
+ pci_slot = slot->pci_slot;
+ if (pci_slot->bus == pci_bus && pci_slot->number == device)
+ return AE_OK;
+ }
+
slot = kmalloc(sizeof(*slot), GFP_KERNEL);
if (!slot) {
err("%s: cannot allocate memory\n", __func__);
@@ -159,12 +148,8 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
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);

@@ -174,131 +159,24 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
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
- * @root: poiner of 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(struct acpi_pci_root *root, acpi_walk_callback user_function)
-{
- acpi_status status;
- acpi_handle handle = root->device->handle;
- struct pci_bus *pci_bus = root->bus;
- struct callback_args context;
-
- 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(struct acpi_pci_root *root)
+void acpi_pci_slot_enumerate(struct pci_bus *bus, acpi_handle handle)
{
- acpi_status status;
-
- status = walk_root_bridge(root, register_slot);
- if (ACPI_FAILURE(status))
- err("%s: register_slot failure - %d\n", __func__, status);
-
- return status;
+ mutex_lock(&slot_list_lock);
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+ register_slot, NULL, bus, NULL);
+ mutex_unlock(&slot_list_lock);
}

-/*
- * acpi_pci_slot_remove
- * @handle: points to an acpi_pci_root
- */
-static void
-acpi_pci_slot_remove(struct acpi_pci_root *root)
+void acpi_pci_slot_remove(struct pci_bus *bus)
{
struct acpi_pci_slot *slot, *tmp;
- struct pci_bus *pbus;
- acpi_handle handle = root->device->handle;

mutex_lock(&slot_list_lock);
list_for_each_entry_safe(slot, tmp, &slot_list, list) {
- if (slot->root_handle == handle) {
+ if (slot->pci_slot->bus == bus) {
list_del(&slot->list);
- pbus = slot->pci_slot->bus;
pci_destroy_slot(slot->pci_slot);
- put_device(&pbus->dev);
+ put_device(&bus->dev);
kfree(slot);
}
}
@@ -333,5 +211,4 @@ static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
void __init acpi_pci_slot_init(void)
{
dmi_check_system(acpi_pci_slot_dmi_table);
- acpi_pci_register_driver(&acpi_pci_slot_driver);
}
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index b643aed..bc2f337 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1687,7 +1687,6 @@ int __init acpi_scan_init(void)

acpi_power_init();
acpi_pci_root_init();
- acpi_pci_slot_init();

/*
* Enumerate devices in the ACPI namespace.
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 99878ac..2dbca38 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -296,7 +296,7 @@ void acpi_pci_add_bus(struct pci_bus *bus)
if (acpi_pci_disabled || handle == NULL)
return;

- /* TODO: add PCI slots and acpiphp hotplug slots */
+ acpi_pci_slot_enumerate(bus, handle);
}

void acpi_pci_remove_bus(struct pci_bus *bus)
@@ -308,7 +308,7 @@ void acpi_pci_remove_bus(struct pci_bus *bus)
if (acpi_pci_disabled)
return;

- /* TODO: remove PCI slots and acpiphp hotplug slots */
+ acpi_pci_slot_remove(bus);
}

/* ACPI bus type */
@@ -381,7 +381,10 @@ static int __init acpi_pci_init(void)
ret = register_acpi_bus_type(&acpi_pci_bus);
if (ret)
return 0;
+
pci_set_platform_pm(&acpi_pci_platform_pm);
+ acpi_pci_slot_init();
+
return 0;
}
arch_initcall(acpi_pci_init);
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 2b1743c..1ef126f 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -44,6 +44,18 @@ static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)

void acpi_pci_add_bus(struct pci_bus *bus);
void acpi_pci_remove_bus(struct pci_bus *bus);
+
+#ifdef CONFIG_ACPI_PCI_SLOT
+extern void acpi_pci_slot_init(void);
+extern void acpi_pci_slot_enumerate(struct pci_bus *bus, acpi_handle handle);
+extern void acpi_pci_slot_remove(struct pci_bus *bus);
+#else
+static inline void acpi_pci_slot_init(void) { }
+static inline void acpi_pci_slot_enumerate(struct pci_bus *bus,
+ acpi_handle handle) { }
+static inline void acpi_pci_slot_remove(struct pci_bus *bus) { }
+#endif
+
#else /* CONFIG_ACPI */
static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
--
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/