From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by ozlabs.org (Postfix) with ESMTP id 4980E2C009B for ; Wed, 30 Jan 2013 19:09:18 +1100 (EST) Date: Tue, 29 Jan 2013 23:48:59 -0500 From: Greg KH To: Toshi Kani Subject: Re: [RFC PATCH v2 01/12] Add sys_hotplug.h for system device hotplug framework Message-ID: <20130130044859.GD30002@kroah.com> References: <1357861230-29549-1-git-send-email-toshi.kani@hp.com> <5036592.TuXAnGzk4M@vostro.rjw.lan> <1358177628.14145.49.camel@misato.fc.hp.com> <2154272.qDAyBlTr8z@vostro.rjw.lan> <1358190124.14145.79.camel@misato.fc.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1358190124.14145.79.camel@misato.fc.hp.com> Cc: linux-s390@vger.kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, linux-mm@kvack.org, yinghai@kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, isimatu.yasuaki@jp.fujitsu.com, srivatsa.bhat@linux.vnet.ibm.com, guohanjun@huawei.com, bhelgaas@google.com, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, lenb@kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Jan 14, 2013 at 12:02:04PM -0700, Toshi Kani wrote: > On Mon, 2013-01-14 at 19:48 +0100, Rafael J. Wysocki wrote: > > On Monday, January 14, 2013 08:33:48 AM Toshi Kani wrote: > > > On Fri, 2013-01-11 at 22:23 +0100, Rafael J. Wysocki wrote: > > > > On Thursday, January 10, 2013 04:40:19 PM Toshi Kani wrote: > > > > > Added include/linux/sys_hotplug.h, which defines the system device > > > > > hotplug framework interfaces used by the framework itself and > > > > > handlers. > > > > > > > > > > The order values define the calling sequence of handlers. For add > > > > > execute, the ordering is ACPI->MEM->CPU. Memory is onlined before > > > > > CPU so that threads on new CPUs can start using their local memory. > > > > > The ordering of the delete execute is symmetric to the add execute. > > > > > > > > > > struct shp_request defines a hot-plug request information. The > > > > > device resource information is managed with a list so that a single > > > > > request may target to multiple devices. > > > > > > > > : > > > > > + > > > > > +struct shp_device { > > > > > + struct list_head list; > > > > > + struct device *device; > > > > > + enum shp_class class; > > > > > + union shp_dev_info info; > > > > > +}; > > > > > + > > > > > +/* > > > > > + * Hot-plug request > > > > > + */ > > > > > +struct shp_request { > > > > > + /* common info */ > > > > > + enum shp_operation operation; /* operation */ > > > > > + > > > > > + /* hot-plug event info: only valid for hot-plug operations */ > > > > > + void *handle; /* FW handle */ > > > > > > > > What's the role of handle here? > > > > > > On ACPI-based platforms, the handle keeps a notified ACPI handle when a > > > hot-plug request is made. ACPI bus handlers, acpi_add_execute() / > > > acpi_del_execute(), then scans / trims ACPI devices from the handle. > > > > OK, so this is ACPI-specific and should be described as such. > > Other FW interface I know is parisc, which has mod_index (module index) > to identify a unique object, just like what ACPI handle does. The > handle can keep the mod_index as an opaque value as well. But as you > said, I do not know if the handle works for all other FWs. So, I will > add descriptions, such that the hot-plug event info is modeled after > ACPI and may need to be revisited when supporting other FW. Please make it a "real" pointer, and not a void *, those shouldn't be used at all if possible. thanks, greg k-h