Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757762Ab2JJDVZ (ORCPT ); Tue, 9 Oct 2012 23:21:25 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:55049 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751278Ab2JJDVX (ORCPT ); Tue, 9 Oct 2012 23:21:23 -0400 Date: Tue, 9 Oct 2012 20:21:20 -0700 From: mark gross To: "Rafael J. Wysocki" Cc: Linux PM list , ACPI Devel Mailing List , Alan Stern , Huang Ying , Sarah Sharp , Lan Tianyu , Aaron Lu , Jean Pihet , linux-pci@vger.kernel.org, Greg Kroah-Hartman , mark gross , LKML Subject: Re: [PATCH 2/7] PM / QoS: Introduce request and constraint data types for PM QoS flags Message-ID: <20121010032120.GB21067@MGROSS-X220VM> Reply-To: markgross@thegnar.org References: <201209282351.10663.rjw@sisk.pl> <1413438.1MkXj8vjQK@vostro.rjw.lan> <5257738.DZvocH2moA@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5257738.DZvocH2moA@vostro.rjw.lan> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5673 Lines: 161 On Mon, Oct 08, 2012 at 10:05:07AM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Introduce struct pm_qos_flags_request and struct pm_qos_flags > representing PM QoS flags request type and PM QoS flags constraint > type, respectively. With these definitions the data structures > will be arranged so that the list member of a struct pm_qos_flags > object will contain the head of a list of struct pm_qos_flags_request > objects representing all of the "flags" requests present for the > given device. Then, the effective_flags member of a struct > pm_qos_flags object will contain the bitwise OR of the flags members > of all the struct pm_qos_flags_request objects in the list. > > Additionally, introduce helper function pm_qos_update_flags() > allowing the caller to manage the list of struct pm_qos_flags_request > pointed to by the list member of struct pm_qos_flags. > > The flags are of type s32 so that the request's "value" field > is always of the same type regardless of what kind of request it > is (latency requests already have value fields of type s32). > > Signed-off-by: Rafael J. Wysocki > Reviewed-by: Jean Pihet > --- > include/linux/pm_qos.h | 17 +++++++++++-- > kernel/power/qos.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 78 insertions(+), 2 deletions(-) > > Index: linux/include/linux/pm_qos.h > =================================================================== > --- linux.orig/include/linux/pm_qos.h > +++ linux/include/linux/pm_qos.h > @@ -33,6 +33,11 @@ struct pm_qos_request { > struct delayed_work work; /* for pm_qos_update_request_timeout */ > }; > > +struct pm_qos_flags_request { > + struct list_head node; > + s32 flags; /* Do not change to 64 bit */ > +}; > + > struct dev_pm_qos_request { > struct plist_node node; > struct device *dev; > @@ -45,8 +50,8 @@ enum pm_qos_type { > }; > > /* > - * Note: The lockless read path depends on the CPU accessing > - * target_value atomically. Atomic access is only guaranteed on all CPU > + * Note: The lockless read path depends on the CPU accessing target_value > + * or effective_flags atomically. Atomic access is only guaranteed on all CPU > * types linux supports for 32 bit quantites > */ > struct pm_qos_constraints { > @@ -57,6 +62,11 @@ struct pm_qos_constraints { > struct blocking_notifier_head *notifiers; > }; > > +struct pm_qos_flags { > + struct list_head list; > + s32 effective_flags; /* Do not change to 64 bit */ > +}; > + > struct dev_pm_qos { > struct pm_qos_constraints latency; > }; > @@ -75,6 +85,9 @@ static inline int dev_pm_qos_request_act > > int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, > enum pm_qos_req_action action, int value); > +bool pm_qos_update_flags(struct pm_qos_flags *pqf, > + struct pm_qos_flags_request *req, > + enum pm_qos_req_action action, s32 val); > void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, > s32 value); > void pm_qos_update_request(struct pm_qos_request *req, > Index: linux/kernel/power/qos.c > =================================================================== > --- linux.orig/kernel/power/qos.c > +++ linux/kernel/power/qos.c > @@ -213,6 +213,69 @@ int pm_qos_update_target(struct pm_qos_c > } > > /** > + * pm_qos_flags_remove_req - Remove device PM QoS flags request. > + * @pqf: Device PM QoS flags set to remove the request from. > + * @req: Request to remove from the set. > + */ > +static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, > + struct pm_qos_flags_request *req) > +{ > + s32 val = 0; > + > + list_del(&req->node); > + list_for_each_entry(req, &pqf->list, node) > + val |= req->flags; > + > + pqf->effective_flags = val; > +} > + > +/** > + * pm_qos_update_flags - Update a set of PM QoS flags. > + * @pqf: Set of flags to update. > + * @req: Request to add to the set, to modify, or to remove from the set. > + * @action: Action to take on the set. > + * @val: Value of the request to add or modify. > + * > + * Update the given set of PM QoS flags and call notifiers if the aggregate > + * value has changed. Returns 1 if the aggregate constraint value has changed, > + * 0 otherwise. > + */ > +bool pm_qos_update_flags(struct pm_qos_flags *pqf, > + struct pm_qos_flags_request *req, > + enum pm_qos_req_action action, s32 val) > +{ > + unsigned long irqflags; > + s32 prev_value, curr_value; > + > + spin_lock_irqsave(&pm_qos_lock, irqflags); > + > + prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; > + > + switch (action) { > + case PM_QOS_REMOVE_REQ: > + pm_qos_flags_remove_req(pqf, req); > + break; > + case PM_QOS_UPDATE_REQ: > + pm_qos_flags_remove_req(pqf, req); > + case PM_QOS_ADD_REQ: > + req->flags = val; > + INIT_LIST_HEAD(&req->node); > + list_add_tail(&req->node, &pqf->list); > + pqf->effective_flags |= val; > + break; > + default: > + /* no action */ > + ; > + } > + > + curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; > + > + spin_unlock_irqrestore(&pm_qos_lock, irqflags); > + > + return prev_value != curr_value; > +} > + > +/** > * pm_qos_request - returns current system wide qos expectation > * @pm_qos_class: identification of which qos value is requested > * > acked-by: mark gross --mark -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/