From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yinghai Lu Subject: Re: [PATCH 4/30] ACPI / hotplug / PCI: Hotplug context objects for bridges and functions Date: Wed, 17 Jul 2013 19:00:33 -0700 Message-ID: References: <26431283.HJCKsss0rt@vostro.rjw.lan> <3718119.FLASu5DBx8@vostro.rjw.lan> <2366394.4EoP1MXmG2@vostro.rjw.lan> <5282264.ht9aNfCcNl@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: <5282264.ht9aNfCcNl@vostro.rjw.lan> Sender: linux-pci-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: ACPI Devel Maling List , Bjorn Helgaas , LKML , Linux PCI , Jiang Liu , Mika Westerberg , "Kirill A. Shutemov" List-Id: linux-acpi@vger.kernel.org On Wed, Jul 17, 2013 at 4:17 PM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > When either a new hotplug bridge or a new hotplug function is added > by the ACPI-based PCI hotplug (ACPIPHP) code, attach a context object > to its ACPI handle to store hotplug-related information in it. To > start with, put the handle's bridge and function pointers into that > object. Count references to the context objects and drop them when > they are not needed any more. > > First of all, this makes it possible to find out if the given bridge > has been registered as a function already in a much more > straightforward way and acpiphp_bridge_handle_to_function() can be > dropped (Yay!). > > This also will allow some more simplifications to be made going > forward. > > Signed-off-by: Rafael J. Wysocki > --- > drivers/pci/hotplug/acpiphp.h | 10 ++ > drivers/pci/hotplug/acpiphp_glue.c | 179 ++++++++++++++++++++++++++++--------- > 2 files changed, 146 insertions(+), 43 deletions(-) no, more lines are added. > > Index: linux-pm/drivers/pci/hotplug/acpiphp.h > =================================================================== > --- linux-pm.orig/drivers/pci/hotplug/acpiphp.h > +++ linux-pm/drivers/pci/hotplug/acpiphp.h > @@ -49,6 +49,7 @@ > #define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME , ## arg) > #define warn(format, arg...) printk(KERN_WARNING "%s: " format, MY_NAME , ## arg) > > +struct acpiphp_context; > struct acpiphp_bridge; > struct acpiphp_slot; > > @@ -77,6 +78,7 @@ struct acpiphp_bridge { > struct kref ref; > acpi_handle handle; > > + struct acpiphp_context *context; > /* Ejectable PCI-to-PCI bridge (PCI bridge and PCI function) */ > struct acpiphp_func *func; > > @@ -119,6 +121,7 @@ struct acpiphp_slot { > * typically 8 objects per slot (i.e. for each PCI function) > */ > struct acpiphp_func { > + struct acpiphp_context *context; > struct acpiphp_slot *slot; /* parent */ > > struct list_head sibling; > @@ -128,6 +131,13 @@ struct acpiphp_func { > u32 flags; /* see below */ > }; > > +struct acpiphp_context { > + acpi_handle handle; > + struct acpiphp_func *func; > + struct acpiphp_bridge *bridge; > + unsigned int refcount; > +}; > + > /* > * struct acpiphp_attention_info - device specific attention registration > * > 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 > @@ -55,6 +55,7 @@ > > static LIST_HEAD(bridge_list); > static DEFINE_MUTEX(bridge_mutex); > +static DEFINE_MUTEX(acpiphp_context_lock); > > #define MY_NAME "acpiphp_glue" > > @@ -79,6 +80,74 @@ is_pci_dock_device(acpi_handle handle, u > } > } > > +static void acpiphp_context_handler(acpi_handle handle, void *context) > +{ > + /* Intentionally empty. */ > +} > + > +/** > + * acpiphp_init_context - Create hotplug context and grab a reference to it. > + * @handle: ACPI object handle to create the context for. > + * > + * Call under acpiphp_context_lock. > + */ > +static struct acpiphp_context *acpiphp_init_context(acpi_handle handle) > +{ > + struct acpiphp_context *context; > + acpi_status status; > + > + context = kzalloc(sizeof(*context), GFP_KERNEL); > + if (!context) > + return NULL; > + > + context->handle = handle; > + context->refcount = 1; > + status = acpi_attach_data(handle, acpiphp_context_handler, context); > + if (ACPI_FAILURE(status)) { > + kfree(context); > + return NULL; > + } > + return context; > +} > + > +/** > + * acpiphp_get_context - Get hotplug context and grab a reference to it. > + * @handle: ACPI object handle to get the context for. > + * > + * Call under acpiphp_context_lock. > + */ > +static struct acpiphp_context *acpiphp_get_context(acpi_handle handle) > +{ > + struct acpiphp_context *context = NULL; > + acpi_status status; > + void *data; > + > + status = acpi_get_data(handle, acpiphp_context_handler, &data); > + if (ACPI_SUCCESS(status)) { > + context = data; > + context->refcount++; > + } > + return context; > +} > + > +/** > + * acpiphp_put_context - Drop a reference to ACPI hotplug context. > + * @handle: ACPI object handle to put the context for. > + * > + * The context object is removed if there are no more references to it. > + * > + * Call under acpiphp_context_lock. > + */ > +static void acpiphp_put_context(struct acpiphp_context *context) > +{ > + if (--context->refcount) > + return; > + > + WARN_ON(context->func || context->bridge); > + acpi_detach_data(context->handle, acpiphp_context_handler); > + kfree(context); > +} > + > static inline void get_bridge(struct acpiphp_bridge *bridge) > { > kref_get(&bridge->ref); > @@ -91,25 +160,37 @@ static inline void put_bridge(struct acp > > static void free_bridge(struct kref *kref) > { > + struct acpiphp_context *context; > struct acpiphp_bridge *bridge; > struct acpiphp_slot *slot, *next; > struct acpiphp_func *func, *tmp; > > + mutex_lock(&acpiphp_context_lock); > + > bridge = container_of(kref, struct acpiphp_bridge, ref); > > list_for_each_entry_safe(slot, next, &bridge->slots, node) { > list_for_each_entry_safe(func, tmp, &slot->funcs, sibling) { > + context = func->context; > + context->func = NULL; > + acpiphp_put_context(context); > kfree(func); > } > kfree(slot); > } > > - /* Release reference acquired by acpiphp_bridge_handle_to_function() */ > + /* Release the reference acquired by acpiphp_enumerate_slots(). */ > if ((bridge->flags & BRIDGE_HAS_EJ0) && bridge->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); > + > + mutex_unlock(&acpiphp_context_lock); > } > > /* > @@ -194,10 +275,11 @@ static void acpiphp_dock_release(void *d > } > > /* callback routine to register each ACPI PCI slot object */ > -static acpi_status > -register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) > +static acpi_status register_slot(acpi_handle handle, u32 lvl, void *data, > + void **rv) > { > - struct acpiphp_bridge *bridge = (struct acpiphp_bridge *)context; > + struct acpiphp_bridge *bridge = data; > + struct acpiphp_context *context; > struct acpiphp_slot *slot; > struct acpiphp_func *newfunc; > acpi_status status = AE_OK; > @@ -230,6 +312,18 @@ register_slot(acpi_handle handle, u32 lv > newfunc->handle = handle; > newfunc->function = function; > > + mutex_lock(&acpiphp_context_lock); > + context = acpiphp_init_context(handle); > + if (!context) { > + mutex_unlock(&acpiphp_context_lock); > + acpi_handle_err(handle, "No hotplug context\n"); > + kfree(newfunc); > + return AE_NOT_EXIST; > + } > + newfunc->context = context; > + context->func = newfunc; > + mutex_unlock(&acpiphp_context_lock); > + > if (acpi_has_method(handle, "_EJ0")) > newfunc->flags = FUNC_HAS_EJ0; > > @@ -266,8 +360,8 @@ register_slot(acpi_handle handle, u32 lv > if (!found) { > slot = kzalloc(sizeof(struct acpiphp_slot), GFP_KERNEL); > if (!slot) { > - kfree(newfunc); > - return AE_NO_MEMORY; > + status = AE_NO_MEMORY; > + goto err_out; > } > > slot->bridge = bridge; > @@ -291,7 +385,9 @@ register_slot(acpi_handle handle, u32 lv > else > warn("acpiphp_register_hotplug_slot failed " > "(err code = 0x%x)\n", retval); > - goto err_exit; > + > + status = AE_OK; > + goto err; > } > } > > @@ -329,15 +425,20 @@ register_slot(acpi_handle handle, u32 lv > > return AE_OK; > > - err_exit: > + err: > bridge->nr_slots--; > mutex_lock(&bridge_mutex); > list_del(&slot->node); > mutex_unlock(&bridge_mutex); > kfree(slot); > - kfree(newfunc); > > - return AE_OK; > + err_out: > + mutex_lock(&acpiphp_context_lock); > + context->func = NULL; > + acpiphp_put_context(context); > + mutex_unlock(&acpiphp_context_lock); > + kfree(newfunc); > + return status; > } > > > @@ -352,32 +453,6 @@ static int detect_ejectable_slots(acpi_h > return found; > } > > - > -/* find acpiphp_func from acpiphp_bridge */ > -static struct acpiphp_func *acpiphp_bridge_handle_to_function(acpi_handle handle) > -{ > - struct acpiphp_bridge *bridge; > - struct acpiphp_slot *slot; > - struct acpiphp_func *func = NULL; > - > - mutex_lock(&bridge_mutex); > - list_for_each_entry(bridge, &bridge_list, list) { > - list_for_each_entry(slot, &bridge->slots, node) { > - list_for_each_entry(func, &slot->funcs, sibling) { > - if (func->handle == handle) { > - get_bridge(func->slot->bridge); > - mutex_unlock(&bridge_mutex); > - return func; > - } > - } > - } > - } > - mutex_unlock(&bridge_mutex); > - > - return NULL; > -} > - > - > static struct acpiphp_bridge *acpiphp_handle_to_bridge(acpi_handle handle) > { > struct acpiphp_bridge *bridge; > @@ -1108,6 +1183,7 @@ static void handle_hotplug_event_func(ac > */ > void acpiphp_enumerate_slots(struct pci_bus *bus) > { > + struct acpiphp_context *context; > struct acpiphp_bridge *bridge; > acpi_handle handle; > acpi_status status; > @@ -1120,8 +1196,8 @@ void acpiphp_enumerate_slots(struct pci_ > return; > > bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL); > - if (bridge == NULL) { > - err("out of memory\n"); > + if (!bridge) { > + acpi_handle_err(handle, "No memory for bridge object\n"); > return; > } > can you put this change in another patch? > @@ -1131,6 +1207,21 @@ void acpiphp_enumerate_slots(struct pci_ > bridge->pci_dev = pci_dev_get(bus->self); > bridge->pci_bus = bus; > > + mutex_lock(&acpiphp_context_lock); > + context = acpiphp_get_context(handle); > + if (!context) { > + context = acpiphp_init_context(handle); > + if (!context) { > + mutex_unlock(&acpiphp_context_lock); > + acpi_handle_err(handle, "No hotplug context\n"); > + kfree(bridge); > + return; > + } > + } > + bridge->context = context; > + context->bridge = bridge; > + mutex_unlock(&acpiphp_context_lock); > + > /* > * Grab a ref to the subordinate PCI bus in case the bus is > * removed via PCI core logical hotplug. The ref pins the bus > @@ -1169,13 +1260,15 @@ void acpiphp_enumerate_slots(struct pci_ > > dbg("found ejectable p2p bridge\n"); > bridge->flags |= BRIDGE_HAS_EJ0; > - bridge->func = acpiphp_bridge_handle_to_function(bridge->handle); > - if (bridge->func) { > - status = acpi_remove_notify_handler(bridge->func->handle, > - ACPI_SYSTEM_NOTIFY, > + 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(bridge->func->handle, > + acpi_handle_err(handle, > "failed to remove notify handler\n"); > } > return; >