From: Luis R. Rodriguez Date: Tue, 12 Jan 2010 01:26:03 +0000 (-0800) Subject: Synch up pm-qos implementation completely with linux-next next-20100111 X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=08ec0d36c10a745bdf37d72cde73c5e048a23152;p=openwrt%2Fstaging%2Fblogic.git Synch up pm-qos implementation completely with linux-next next-20100111 This should be easier to keep track of and backport now for older kernels. As we move along each new kernel release will get a branch and have its own pm-qos implementation, the master tag will always keep backporting the latest bleedinge edge (from linux-next). Signed-off-by: Luis R. Rodriguez --- diff --git a/compat/pm_qos_params.c b/compat/pm_qos_params.c index 5ce3d0b16374..30aeddf82177 100644 --- a/compat/pm_qos_params.c +++ b/compat/pm_qos_params.c @@ -1,12 +1,53 @@ #include -/* All things not in 2.6.22, 2.6.23 and 2.6.24 */ +/* This is the backport of pm-qos params for kernels <= 2.6.25 */ #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)) +/* + * This module exposes the interface to kernel space for specifying + * QoS dependencies. It provides infrastructure for registration of: + * + * Dependents on a QoS value : register requirements + * Watchers of QoS value : get notified when target QoS value changes + * + * This QoS design is best effort based. Dependents register their QoS needs. + * Watchers register to keep track of the current QoS needs of the system. + * + * There are 3 basic classes of QoS parameter: latency, timeout, throughput + * each have defined units: + * latency: usec + * timeout: usec <-- currently not used. + * throughput: kbs (kilo byte / sec) + * + * There are lists of pm_qos_objects each one wrapping requirements, notifiers + * + * User mode requirements on a QOS parameter register themselves to the + * subsystem by opening the device node /dev/... and writing there request to + * the node. As long as the process holds a file handle open to the node the + * client continues to be accounted for. Upon file release the usermode + * requirement is removed and a new qos target is computed. This way when the + * requirement that the application has is cleaned up when closes the file + * pointer or exits the pm_qos_object will get an opportunity to clean up. + * + * Mark Gross + */ + +#include +#include +#include +#include +#include +#include +#include #include +#include +#include +#include + +#include /* - * locking rule: all changes to target_value or requirements or notifiers lists + * locking rule: all changes to requirements or notifiers lists * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock * held, taken with _irqsave. One lock to rule them all */ @@ -29,7 +70,7 @@ struct pm_qos_object { struct miscdevice pm_qos_power_miscdev; char *name; s32 default_value; - s32 target_value; + atomic_t target_value; s32 (*comparitor)(s32, s32); }; @@ -40,7 +81,7 @@ static struct pm_qos_object cpu_dma_pm_qos = { .notifiers = &cpu_dma_lat_notifier, .name = "cpu_dma_latency", .default_value = 2000 * USEC_PER_SEC, - .target_value = 2000 * USEC_PER_SEC, + .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC), .comparitor = min_compare }; @@ -50,7 +91,7 @@ static struct pm_qos_object network_lat_pm_qos = { .notifiers = &network_lat_notifier, .name = "network_latency", .default_value = 2000 * USEC_PER_SEC, - .target_value = 2000 * USEC_PER_SEC, + .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC), .comparitor = min_compare }; @@ -62,7 +103,7 @@ static struct pm_qos_object network_throughput_pm_qos = { .notifiers = &network_throughput_notifier, .name = "network_throughput", .default_value = 0, - .target_value = 0, + .target_value = ATOMIC_INIT(0), .comparitor = max_compare }; @@ -73,12 +114,12 @@ static struct pm_qos_object system_bus_freq_pm_qos = { .notifiers = &system_bus_freq_notifier, .name = "system_bus_freq", .default_value = 0, - .target_value = 0, + .target_value = ATOMIC_INIT(0), .comparitor = max_compare }; -static struct pm_qos_object *pm_qos_array[] = { +static struct pm_qos_object *pm_qos_array[PM_QOS_NUM_CLASSES] = { [PM_QOS_RESERVED] = &null_pm_qos, [PM_QOS_CPU_DMA_LATENCY] = &cpu_dma_pm_qos, [PM_QOS_NETWORK_LATENCY] = &network_lat_pm_qos, @@ -94,9 +135,9 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp); static int pm_qos_power_release(struct inode *inode, struct file *filp); static const struct file_operations pm_qos_power_fops = { - .write = pm_qos_power_write, - .open = pm_qos_power_open, - .release = pm_qos_power_release, + .write = pm_qos_power_write, + .open = pm_qos_power_open, + .release = pm_qos_power_release, }; /* static helper functions */ @@ -110,6 +151,7 @@ static s32 min_compare(s32 v1, s32 v2) return min(v1, v2); } + static void update_target(int target) { s32 extreme_value; @@ -124,11 +166,11 @@ static void update_target(int target) extreme_value = pm_qos_array[target]->comparitor( extreme_value, node->value); } - if (pm_qos_array[target]->target_value != extreme_value) { + if (atomic_read(&pm_qos_array[target]->target_value) != extreme_value) { call_notifier = 1; - pm_qos_array[target]->target_value = extreme_value; + atomic_set(&pm_qos_array[target]->target_value, extreme_value); pr_debug(KERN_ERR "new target for qos %d is %d\n", target, - pm_qos_array[target]->target_value); + atomic_read(&pm_qos_array[target]->target_value)); } spin_unlock_irqrestore(&pm_qos_lock, flags); @@ -167,14 +209,7 @@ static int find_pm_qos_object_by_minor(int minor) */ int pm_qos_requirement(int pm_qos_class) { - int ret_val; - unsigned long flags; - - spin_lock_irqsave(&pm_qos_lock, flags); - ret_val = pm_qos_array[pm_qos_class]->target_value; - spin_unlock_irqrestore(&pm_qos_lock, flags); - - return ret_val; + return atomic_read(&pm_qos_array[pm_qos_class]->target_value); } EXPORT_SYMBOL_GPL(pm_qos_requirement); @@ -185,8 +220,8 @@ EXPORT_SYMBOL_GPL(pm_qos_requirement); * @value: defines the qos request * * This function inserts a new entry in the pm_qos_class list of requested qos - * performance charactoistics. It recomputes the agregate QoS expectations for - * the pm_qos_class of parrameters. + * performance characteristics. It recomputes the aggregate QoS expectations + * for the pm_qos_class of parameters. */ int pm_qos_add_requirement(int pm_qos_class, char *name, s32 value) { @@ -224,10 +259,10 @@ EXPORT_SYMBOL_GPL(pm_qos_add_requirement); * @name: identifies the request * @value: defines the qos request * - * Updates an existing qos requierement for the pm_qos_class of parameters along + * Updates an existing qos requirement for the pm_qos_class of parameters along * with updating the target pm_qos_class value. * - * If the named request isn't in the lest then no change is made. + * If the named request isn't in the list then no change is made. */ int pm_qos_update_requirement(int pm_qos_class, char *name, s32 new_value) { @@ -261,7 +296,7 @@ EXPORT_SYMBOL_GPL(pm_qos_update_requirement); * @pm_qos_class: identifies which list of qos request to us * @name: identifies the request * - * Will remove named qos request from pm_qos_class list of parrameters and + * Will remove named qos request from pm_qos_class list of parameters and * recompute the current target value for the pm_qos_class. */ void pm_qos_remove_requirement(int pm_qos_class, char *name) @@ -293,9 +328,9 @@ EXPORT_SYMBOL_GPL(pm_qos_remove_requirement); * @notifier: notifier block managed by caller. * * will register the notifier into a notification chain that gets called - * uppon changes to the pm_qos_class target value. + * upon changes to the pm_qos_class target value. */ - int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) +int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) { int retval; @@ -312,7 +347,7 @@ EXPORT_SYMBOL_GPL(pm_qos_add_notifier); * @notifier: notifier block to be removed. * * will remove the notifier from the notification chain that gets called - * uppon changes to the pm_qos_class target value. + * upon changes to the pm_qos_class target value. */ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) { @@ -325,33 +360,33 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) } EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); -#define PID_NAME_LEN sizeof("process_1234567890") -static char name[PID_NAME_LEN]; +#define PID_NAME_LEN 32 static int pm_qos_power_open(struct inode *inode, struct file *filp) { int ret; long pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { filp->private_data = (void *)pm_qos_class; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); ret = pm_qos_add_requirement(pm_qos_class, name, PM_QOS_DEFAULT_VALUE); if (ret >= 0) return 0; } - return -EPERM; } static int pm_qos_power_release(struct inode *inode, struct file *filp) { int pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = (long)filp->private_data; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); pm_qos_remove_requirement(pm_qos_class, name); return 0; @@ -362,18 +397,20 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, { s32 value; int pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = (long)filp->private_data; if (count != sizeof(s32)) return -EINVAL; if (copy_from_user(&value, buf, sizeof(s32))) return -EFAULT; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); pm_qos_update_requirement(pm_qos_class, name, value); return sizeof(s32); } + /* * This initializes pm-qos for older kernels. */ @@ -398,13 +435,10 @@ int compat_pm_qos_power_init(void) return ret; } ret = register_pm_qos_misc(&system_bus_freq_pm_qos); - if (ret < 0) { + if (ret < 0) printk(KERN_ERR - "pm_qos_param: network_throughput setup failed\n"); - return ret; - } + "pm_qos_param: system_bus_freq setup failed\n"); return ret; } - #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25) */