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Message-ID: <5248420.dTt3AhzoPf@vostro.rjw.lan>
Date: Fri, 12 Jul 2013 01:40:57 +0200
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: ACPI Devel Maling List <linux-acpi@...r.kernel.org>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>,
LKML <linux-kernel@...r.kernel.org>,
Linux PCI <linux-pci@...r.kernel.org>,
Yinghai Lu <yinghai@...nel.org>, Jiang Liu <liuj97@...il.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: [RFC][PATCH 5/30] ACPI / hotplug / PCI: Unified notify handler for hotplug events
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Using the hotplug context objects introduced previously rework the
ACPI-based PCI hotplug (ACPIPHP) core code so that all notifications
for ACPI device objects corresponding to the hotplug PCI devices are
handled by one function, handle_hotplug_event(), which recognizes
whether it has to handle a bridge or a function.
In addition to code size reduction it allows some ugly pieces of code
where notify handlers have to be uninstalled and installed again to
go away. Moreover, it fixes a theoretically possible race between
handle_hotplug_event() and free_bridge() tearing down data structures
for the same handle.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
drivers/pci/hotplug/acpiphp.h | 1
drivers/pci/hotplug/acpiphp_glue.c | 133 ++++++++++++++-----------------------
2 files changed, 54 insertions(+), 80 deletions(-)
Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c
===================================================================
--- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c
+++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c
@@ -59,11 +59,10 @@ static DEFINE_MUTEX(acpiphp_context_lock
#define MY_NAME "acpiphp_glue"
-static void handle_hotplug_event_bridge (acpi_handle, u32, void *);
+static void handle_hotplug_event(acpi_handle handle, u32 type, void *data);
static void acpiphp_sanitize_bus(struct pci_bus *bus);
static void acpiphp_set_hpp_values(struct pci_bus *bus);
static void hotplug_event_func(acpi_handle handle, u32 type, void *context);
-static void handle_hotplug_event_func(acpi_handle handle, u32 type, void *context);
static void free_bridge(struct kref *kref);
/* callback routine to check for the existence of a pci dock device */
@@ -179,13 +178,13 @@ static void free_bridge(struct kref *kre
kfree(slot);
}
+ context = bridge->context;
/* Release the reference acquired by acpiphp_enumerate_slots(). */
- if ((bridge->flags & BRIDGE_HAS_EJ0) && bridge->func)
+ if (context->handler_for_func)
put_bridge(bridge->func->slot->bridge);
put_device(&bridge->pci_bus->dev);
pci_dev_put(bridge->pci_dev);
- context = bridge->context;
context->bridge = NULL;
acpiphp_put_context(context);
kfree(bridge);
@@ -424,12 +423,12 @@ static acpi_status register_slot(acpi_ha
/* install notify handler */
if (!(newfunc->flags & FUNC_HAS_DCK)) {
- status = acpi_install_notify_handler(handle,
- ACPI_SYSTEM_NOTIFY,
- handle_hotplug_event_func,
- newfunc);
-
- if (ACPI_FAILURE(status))
+ status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+ handle_hotplug_event,
+ context);
+ if (ACPI_SUCCESS(status))
+ context->handler_for_func = true;
+ else
err("failed to register interrupt notify handler\n");
}
@@ -486,23 +485,13 @@ static void cleanup_bridge(struct acpiph
acpi_status status;
acpi_handle handle = bridge->handle;
- if (!pci_is_root_bus(bridge->pci_bus)) {
- status = acpi_remove_notify_handler(handle,
- ACPI_SYSTEM_NOTIFY,
- handle_hotplug_event_bridge);
+ if (!bridge->context->handler_for_func) {
+ status = acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+ handle_hotplug_event);
if (ACPI_FAILURE(status))
err("failed to remove notify handler\n");
}
- if ((bridge->flags & BRIDGE_HAS_EJ0) && bridge->func) {
- status = acpi_install_notify_handler(bridge->func->handle,
- ACPI_SYSTEM_NOTIFY,
- handle_hotplug_event_func,
- bridge->func);
- if (ACPI_FAILURE(status))
- err("failed to install interrupt notify handler\n");
- }
-
list_for_each_entry(slot, &bridge->slots, node) {
list_for_each_entry(func, &slot->funcs, sibling) {
if (is_dock_device(func->handle)) {
@@ -510,9 +499,10 @@ static void cleanup_bridge(struct acpiph
unregister_dock_notifier(&func->nb);
}
if (!(func->flags & FUNC_HAS_DCK)) {
+ func->context->handler_for_func = false;
status = acpi_remove_notify_handler(func->handle,
- ACPI_SYSTEM_NOTIFY,
- handle_hotplug_event_func);
+ ACPI_SYSTEM_NOTIFY,
+ handle_hotplug_event);
if (ACPI_FAILURE(status))
err("failed to remove notify handler\n");
}
@@ -1093,31 +1083,6 @@ static void _handle_hotplug_event_bridge
put_bridge(bridge);
}
-/**
- * handle_hotplug_event_bridge - handle ACPI event on bridges
- * @handle: Notify()'ed acpi_handle
- * @type: Notify code
- * @context: pointer to acpiphp_bridge structure
- *
- * Handles ACPI event notification on {host,p2p} bridges.
- */
-static void handle_hotplug_event_bridge(acpi_handle handle, u32 type,
- void *context)
-{
- struct acpiphp_bridge *bridge = context;
-
- /*
- * Currently the code adds all hotplug events to the kacpid_wq
- * queue when it should add hotplug events to the kacpi_hotplug_wq.
- * The proper way to fix this is to reorganize the code so that
- * drivers (dock, etc.) do not call acpi_os_execute(), etc.
- * For now just re-add this work to the kacpi_hotplug_wq so we
- * don't deadlock on hotplug actions.
- */
- get_bridge(bridge);
- alloc_acpi_hp_work(handle, type, context, _handle_hotplug_event_bridge);
-}
-
static void hotplug_event_func(acpi_handle handle, u32 type, void *context)
{
struct acpiphp_func *func = context;
@@ -1175,17 +1140,33 @@ static void _handle_hotplug_event_func(s
}
/**
- * handle_hotplug_event_func - handle ACPI event on functions (i.e. slots)
+ * handle_hotplug_event - handle ACPI hotplug event
* @handle: Notify()'ed acpi_handle
* @type: Notify code
- * @context: pointer to acpiphp_func structure
+ * @data: pointer to acpiphp_context structure
*
* Handles ACPI event notification on slots.
*/
-static void handle_hotplug_event_func(acpi_handle handle, u32 type,
- void *context)
+static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
{
- struct acpiphp_func *func = context;
+ struct acpiphp_context *context;
+ void (*work_func)(struct work_struct *work) = NULL;
+
+ mutex_lock(&acpiphp_context_lock);
+ context = acpiphp_get_context(handle);
+ if (context) {
+ if (context->bridge) {
+ get_bridge(context->bridge);
+ data = context->bridge;
+ work_func = _handle_hotplug_event_bridge;
+ } else if (context->func) {
+ get_bridge(context->func->slot->bridge);
+ data = context->func;
+ work_func = _handle_hotplug_event_func;
+ }
+ acpiphp_put_context(context);
+ }
+ mutex_unlock(&acpiphp_context_lock);
/*
* Currently the code adds all hotplug events to the kacpid_wq
@@ -1195,8 +1176,8 @@ static void handle_hotplug_event_func(ac
* For now just re-add this work to the kacpi_hotplug_wq so we
* don't deadlock on hotplug actions.
*/
- get_bridge(func->slot->bridge);
- alloc_acpi_hp_work(handle, type, context, _handle_hotplug_event_func);
+ if (work_func)
+ alloc_acpi_hp_work(handle, type, data, work_func);
}
/*
@@ -1267,33 +1248,25 @@ void acpiphp_enumerate_slots(struct pci_
if (pci_is_root_bus(bridge->pci_bus))
return;
+ status = acpi_get_handle(bridge->handle, "_EJ0", &handle);
+ if (ACPI_SUCCESS(status)) {
+ dbg("found ejectable p2p bridge\n");
+ bridge->flags |= BRIDGE_HAS_EJ0;
+ }
+ if (context->handler_for_func) {
+ /* Notify handler already installed. */
+ bridge->func = context->func;
+ get_bridge(context->func->slot->bridge);
+ return;
+ }
+
/* install notify handler for P2P bridges */
status = acpi_install_notify_handler(bridge->handle, ACPI_SYSTEM_NOTIFY,
- handle_hotplug_event_bridge,
- bridge);
- if (ACPI_FAILURE(status)) {
- acpi_handle_err(bridge->handle,
- "failed to register notify handler\n");
- goto err;
- }
- status = acpi_get_handle(bridge->handle, "_EJ0", &handle);
- if (ACPI_FAILURE(status))
+ handle_hotplug_event, NULL);
+ if (ACPI_SUCCESS(status))
return;
- dbg("found ejectable p2p bridge\n");
- bridge->flags |= BRIDGE_HAS_EJ0;
- if (context->func) {
- get_bridge(context->func->slot->bridge);
- bridge->func = context->func;
- handle = context->handle;
- WARN_ON(bridge->handle != handle);
- status = acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
- handle_hotplug_event_func);
- if (ACPI_FAILURE(status))
- acpi_handle_err(handle,
- "failed to remove notify handler\n");
- }
- return;
+ acpi_handle_err(bridge->handle, "failed to register notify handler\n");
err:
cleanup_bridge(bridge);
Index: linux-pm/drivers/pci/hotplug/acpiphp.h
===================================================================
--- linux-pm.orig/drivers/pci/hotplug/acpiphp.h
+++ linux-pm/drivers/pci/hotplug/acpiphp.h
@@ -137,6 +137,7 @@ struct acpiphp_context {
struct acpiphp_func *func;
struct acpiphp_bridge *bridge;
unsigned int refcount;
+ bool handler_for_func;
};
/*
--
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