Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754663Ab2JJDhY (ORCPT ); Tue, 9 Oct 2012 23:37:24 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:49643 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753344Ab2JJDhS (ORCPT ); Tue, 9 Oct 2012 23:37:18 -0400 Date: Tue, 9 Oct 2012 20:37:16 -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 4/7] PM / QoS: Introduce PM QoS device flags support Message-ID: <20121010033716.GF21067@MGROSS-X220VM> Reply-To: markgross@thegnar.org References: <201209282351.10663.rjw@sisk.pl> <1413438.1MkXj8vjQK@vostro.rjw.lan> <3073514.BL1dL4hrR5@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3073514.BL1dL4hrR5@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: 12218 Lines: 357 On Mon, Oct 08, 2012 at 10:07:10AM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Modify the device PM QoS core code to support PM QoS flags requests. > > First, add a new field of type struct pm_qos_flags called "flags" > to struct dev_pm_qos for representing the list of PM QoS flags > requests for the given device. Accordingly, add a new "type" field > to struct dev_pm_qos_request (along with an enum for representing > request types) and a new member called "flr" to its data union for > representig flags requests. > > Second, modify dev_pm_qos_add_request(), dev_pm_qos_update_request(), > the internal routine apply_constraint() used by them and their > existing callers to cover flags requests as well as latency > requests. In particular, dev_pm_qos_add_request() gets a new > argument called "type" for specifying the type of a request to be > added. > > Finally, introduce two routines, __dev_pm_qos_flags() and > dev_pm_qos_flags(), allowing their callers to check which PM QoS > flags have been requested for the given device (the caller is > supposed to pass the mask of flags to check as the routine's > second argument and examine its return value for the result). > > Signed-off-by: Rafael J. Wysocki > Reviewed-by: Jean Pihet > --- > Documentation/power/pm_qos_interface.txt | 2 > drivers/base/power/qos.c | 124 ++++++++++++++++++++++++------- > drivers/mtd/nand/sh_flctl.c | 4 - > include/linux/pm_qos.h | 26 ++++++ > 4 files changed, 127 insertions(+), 29 deletions(-) > > Index: linux/drivers/base/power/qos.c > =================================================================== > --- linux.orig/drivers/base/power/qos.c > +++ linux/drivers/base/power/qos.c > @@ -48,6 +48,50 @@ static DEFINE_MUTEX(dev_pm_qos_mtx); > static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers); > > /** > + * __dev_pm_qos_flags - Check PM QoS flags for a given device. > + * @dev: Device to check the PM QoS flags for. > + * @mask: Flags to check against. > + * > + * This routine must be called with dev->power.lock held. > + */ > +enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask) > +{ > + struct dev_pm_qos *qos = dev->power.qos; > + struct pm_qos_flags *pqf; > + s32 val; > + > + if (!qos) > + return PM_QOS_FLAGS_UNDEFINED; > + > + pqf = &qos->flags; > + if (list_empty(&pqf->list)) > + return PM_QOS_FLAGS_UNDEFINED; > + > + val = pqf->effective_flags & mask; > + if (val) > + return (val == mask) ? PM_QOS_FLAGS_ALL : PM_QOS_FLAGS_SOME; > + > + return PM_QOS_FLAGS_NONE; > +} > + > +/** > + * dev_pm_qos_flags - Check PM QoS flags for a given device (locked). > + * @dev: Device to check the PM QoS flags for. > + * @mask: Flags to check against. > + */ > +enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask) > +{ > + unsigned long irqflags; > + enum pm_qos_flags_status ret; > + > + spin_lock_irqsave(&dev->power.lock, irqflags); > + ret = __dev_pm_qos_flags(dev, mask); > + spin_unlock_irqrestore(&dev->power.lock, irqflags); > + > + return ret; > +} > + > +/** > * __dev_pm_qos_read_value - Get PM QoS constraint for a given device. > * @dev: Device to get the PM QoS constraint value for. > * > @@ -74,30 +118,39 @@ s32 dev_pm_qos_read_value(struct device > return ret; > } > > -/* > - * apply_constraint > - * @req: constraint request to apply > - * @action: action to perform add/update/remove, of type enum pm_qos_req_action > - * @value: defines the qos request > +/** > + * apply_constraint - Add/modify/remove device PM QoS request. > + * @req: Constraint request to apply > + * @action: Action to perform (add/update/remove). > + * @value: Value to assign to the QoS request. > * > * Internal function to update the constraints list using the PM QoS core > * code and if needed call the per-device and the global notification > * callbacks > */ > static int apply_constraint(struct dev_pm_qos_request *req, > - enum pm_qos_req_action action, int value) > + enum pm_qos_req_action action, s32 value) > { > - int ret, curr_value; > - > - ret = pm_qos_update_target(&req->dev->power.qos->latency, > - &req->data.pnode, action, value); > + struct dev_pm_qos *qos = req->dev->power.qos; > + int ret; > > - if (ret) { > - /* Call the global callbacks if needed */ > - curr_value = pm_qos_read_value(&req->dev->power.qos->latency); > - blocking_notifier_call_chain(&dev_pm_notifiers, > - (unsigned long)curr_value, > - req); > + switch(req->type) { > + case DEV_PM_QOS_LATENCY: > + ret = pm_qos_update_target(&qos->latency, &req->data.pnode, > + action, value); > + if (ret) { > + value = pm_qos_read_value(&qos->latency); > + blocking_notifier_call_chain(&dev_pm_notifiers, > + (unsigned long)value, > + req); > + } > + break; > + case DEV_PM_QOS_FLAGS: > + ret = pm_qos_update_flags(&qos->flags, &req->data.flr, > + action, value); > + break; > + default: > + ret = -EINVAL; > } > > return ret; > @@ -134,6 +187,8 @@ static int dev_pm_qos_constraints_alloca > c->type = PM_QOS_MIN; > c->notifiers = n; > > + INIT_LIST_HEAD(&qos->flags.list); > + > spin_lock_irq(&dev->power.lock); > dev->power.qos = qos; > spin_unlock_irq(&dev->power.lock); > @@ -207,6 +262,7 @@ void dev_pm_qos_constraints_destroy(stru > * dev_pm_qos_add_request - inserts new qos request into the list > * @dev: target device for the constraint > * @req: pointer to a preallocated handle > + * @type: type of the request > * @value: defines the qos request > * > * This function inserts a new entry in the device constraints list of > @@ -222,7 +278,7 @@ void dev_pm_qos_constraints_destroy(stru > * from the system. > */ > int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, > - s32 value) > + enum dev_pm_qos_req_type type, s32 value) > { > int ret = 0; > > @@ -253,8 +309,10 @@ int dev_pm_qos_add_request(struct device > } > } > > - if (!ret) > + if (!ret) { > + req->type = type; > ret = apply_constraint(req, PM_QOS_ADD_REQ, value); > + } > > out: > mutex_unlock(&dev_pm_qos_mtx); > @@ -281,6 +339,7 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_add_request > int dev_pm_qos_update_request(struct dev_pm_qos_request *req, > s32 new_value) > { > + s32 curr_value; > int ret = 0; > > if (!req) /*guard against callers passing in null */ > @@ -292,15 +351,27 @@ int dev_pm_qos_update_request(struct dev > > mutex_lock(&dev_pm_qos_mtx); > > - if (req->dev->power.qos) { > - if (new_value != req->data.pnode.prio) > - ret = apply_constraint(req, PM_QOS_UPDATE_REQ, > - new_value); > - } else { > - /* Return if the device has been removed */ > + if (!req->dev->power.qos) { > ret = -ENODEV; > + goto out; > } > > + switch(req->type) { > + case DEV_PM_QOS_LATENCY: > + curr_value = req->data.pnode.prio; > + break; > + case DEV_PM_QOS_FLAGS: > + curr_value = req->data.flr.flags; > + break; > + default: > + ret = -EINVAL; > + goto out; > + } > + > + if (curr_value != new_value) > + ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value); > + > + out: > mutex_unlock(&dev_pm_qos_mtx); > return ret; > } > @@ -451,7 +522,8 @@ int dev_pm_qos_add_ancestor_request(stru > ancestor = ancestor->parent; > > if (ancestor) > - error = dev_pm_qos_add_request(ancestor, req, value); > + error = dev_pm_qos_add_request(ancestor, req, > + DEV_PM_QOS_LATENCY, value); > > if (error) > req->dev = NULL; > @@ -487,7 +559,7 @@ int dev_pm_qos_expose_latency_limit(stru > if (!req) > return -ENOMEM; > > - ret = dev_pm_qos_add_request(dev, req, value); > + ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_LATENCY, value); > if (ret < 0) > return ret; > > Index: linux/include/linux/pm_qos.h > =================================================================== > --- linux.orig/include/linux/pm_qos.h > +++ linux/include/linux/pm_qos.h > @@ -20,6 +20,13 @@ enum { > PM_QOS_NUM_CLASSES, > }; > > +enum pm_qos_flags_status { > + PM_QOS_FLAGS_UNDEFINED = -1, > + PM_QOS_FLAGS_NONE, > + PM_QOS_FLAGS_SOME, > + PM_QOS_FLAGS_ALL, > +}; > + > #define PM_QOS_DEFAULT_VALUE -1 > > #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) > @@ -38,9 +45,16 @@ struct pm_qos_flags_request { > s32 flags; /* Do not change to 64 bit */ > }; > > +enum dev_pm_qos_req_type { > + DEV_PM_QOS_LATENCY = 1, > + DEV_PM_QOS_FLAGS, > +}; > + > struct dev_pm_qos_request { > + enum dev_pm_qos_req_type type; > union { > struct plist_node pnode; > + struct pm_qos_flags_request flr; > } data; > struct device *dev; > }; > @@ -71,6 +85,7 @@ struct pm_qos_flags { > > struct dev_pm_qos { > struct pm_qos_constraints latency; > + struct pm_qos_flags flags; > }; > > /* Action requested to pm_qos_update_target */ > @@ -105,10 +120,12 @@ int pm_qos_request_active(struct pm_qos_ > s32 pm_qos_read_value(struct pm_qos_constraints *c); > > #ifdef CONFIG_PM > +enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask); > +enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask); > s32 __dev_pm_qos_read_value(struct device *dev); > s32 dev_pm_qos_read_value(struct device *dev); > int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, > - s32 value); > + enum dev_pm_qos_req_type type, s32 value); > int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value); > int dev_pm_qos_remove_request(struct dev_pm_qos_request *req); > int dev_pm_qos_add_notifier(struct device *dev, > @@ -122,12 +139,19 @@ void dev_pm_qos_constraints_destroy(stru > int dev_pm_qos_add_ancestor_request(struct device *dev, > struct dev_pm_qos_request *req, s32 value); > #else > +static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, > + s32 mask) > + { return PM_QOS_FLAGS_UNDEFINED; } > +static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, > + s32 mask) > + { return PM_QOS_FLAGS_UNDEFINED; } > static inline s32 __dev_pm_qos_read_value(struct device *dev) > { return 0; } > static inline s32 dev_pm_qos_read_value(struct device *dev) > { return 0; } > static inline int dev_pm_qos_add_request(struct device *dev, > struct dev_pm_qos_request *req, > + enum dev_pm_qos_req_type type, > s32 value) > { return 0; } > static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req, > Index: linux/drivers/mtd/nand/sh_flctl.c > =================================================================== > --- linux.orig/drivers/mtd/nand/sh_flctl.c > +++ linux/drivers/mtd/nand/sh_flctl.c > @@ -710,7 +710,9 @@ static void flctl_select_chip(struct mtd > > if (!flctl->qos_request) { > ret = dev_pm_qos_add_request(&flctl->pdev->dev, > - &flctl->pm_qos, 100); > + &flctl->pm_qos, > + DEV_PM_QOS_LATENCY, > + 100); > if (ret < 0) > dev_err(&flctl->pdev->dev, > "PM QoS request failed: %d\n", ret); > Index: linux/Documentation/power/pm_qos_interface.txt > =================================================================== > --- linux.orig/Documentation/power/pm_qos_interface.txt > +++ linux/Documentation/power/pm_qos_interface.txt > @@ -99,7 +99,7 @@ reading the aggregated value does not re > > From kernel mode the use of this interface is the following: > > -int dev_pm_qos_add_request(device, handle, value): > +int dev_pm_qos_add_request(device, handle, type, value): > Will insert an element into the list for that identified device with the > target value. Upon change to this list the new target is recomputed and any > registered notifiers are called only if the target value is now different. > Reviewed-by: mark gross -- 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/