Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 673 insertions, 0 deletions

diff --git a/kernel/power/qos.c b/kernel/power/qos.c
new file mode 100644
index 000000000..ec7e1e859
--- /dev/null
+++ b/kernel/power/qos.c
@@ -0,0 +1,673 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Power Management Quality of Service (PM QoS) support base.
+ *
+ * Copyright (C) 2020 Intel Corporation
+ *
+ * Authors:
+ *	Mark Gross <mgross@linux.intel.com>
+ *	Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * Provided here is an interface for specifying PM QoS dependencies.  It allows
+ * entities depending on QoS constraints to register their requests which are
+ * aggregated as appropriate to produce effective constraints (target values)
+ * that can be monitored by entities needing to respect them, either by polling
+ * or through a built-in notification mechanism.
+ *
+ * In addition to the basic functionality, more specific interfaces for managing
+ * global CPU latency QoS requests and frequency QoS requests are provided.
+ */
+
+/*#define DEBUG*/
+
+#include <linux/pm_qos.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/string.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <trace/events/power.h>
+
+/*
+ * locking rule: all changes to constraints 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
+ */
+static DEFINE_SPINLOCK(pm_qos_lock);
+
+/**
+ * pm_qos_read_value - Return the current effective constraint value.
+ * @c: List of PM QoS constraint requests.
+ */
+s32 pm_qos_read_value(struct pm_qos_constraints *c)
+{
+	return READ_ONCE(c->target_value);
+}
+
+static int pm_qos_get_value(struct pm_qos_constraints *c)
+{
+	if (plist_head_empty(&c->list))
+		return c->no_constraint_value;
+
+	switch (c->type) {
+	case PM_QOS_MIN:
+		return plist_first(&c->list)->prio;
+
+	case PM_QOS_MAX:
+		return plist_last(&c->list)->prio;
+
+	default:
+		WARN(1, "Unknown PM QoS type in %s\n", __func__);
+		return PM_QOS_DEFAULT_VALUE;
+	}
+}
+
+static void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
+{
+	WRITE_ONCE(c->target_value, value);
+}
+
+/**
+ * pm_qos_update_target - Update a list of PM QoS constraint requests.
+ * @c: List of PM QoS requests.
+ * @node: Target list entry.
+ * @action: Action to carry out (add, update or remove).
+ * @value: New request value for the target list entry.
+ *
+ * Update the given list of PM QoS constraint requests, @c, by carrying an
+ * @action involving the @node list entry and @value on it.
+ *
+ * The recognized values of @action are PM_QOS_ADD_REQ (store @value in @node
+ * and add it to the list), PM_QOS_UPDATE_REQ (remove @node from the list, store
+ * @value in it and add it to the list again), and PM_QOS_REMOVE_REQ (remove
+ * @node from the list, ignore @value).
+ *
+ * Return: 1 if the aggregate constraint value has changed, 0  otherwise.
+ */
+int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
+			 enum pm_qos_req_action action, int value)
+{
+	int prev_value, curr_value, new_value;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pm_qos_lock, flags);
+
+	prev_value = pm_qos_get_value(c);
+	if (value == PM_QOS_DEFAULT_VALUE)
+		new_value = c->default_value;
+	else
+		new_value = value;
+
+	switch (action) {
+	case PM_QOS_REMOVE_REQ:
+		plist_del(node, &c->list);
+		break;
+	case PM_QOS_UPDATE_REQ:
+		/*
+		 * To change the list, atomically remove, reinit with new value
+		 * and add, then see if the aggregate has changed.
+		 */
+		plist_del(node, &c->list);
+		fallthrough;
+	case PM_QOS_ADD_REQ:
+		plist_node_init(node, new_value);
+		plist_add(node, &c->list);
+		break;
+	default:
+		/* no action */
+		;
+	}
+
+	curr_value = pm_qos_get_value(c);
+	pm_qos_set_value(c, curr_value);
+
+	spin_unlock_irqrestore(&pm_qos_lock, flags);
+
+	trace_pm_qos_update_target(action, prev_value, curr_value);
+
+	if (prev_value == curr_value)
+		return 0;
+
+	if (c->notifiers)
+		blocking_notifier_call_chain(c->notifiers, curr_value, NULL);
+
+	return 1;
+}
+
+/**
+ * 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 PM QoS 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.
+ *
+ * Return: 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);
+		fallthrough;
+	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);
+
+	trace_pm_qos_update_flags(action, prev_value, curr_value);
+
+	return prev_value != curr_value;
+}
+
+#ifdef CONFIG_CPU_IDLE
+/* Definitions related to the CPU latency QoS. */
+
+static struct pm_qos_constraints cpu_latency_constraints = {
+	.list = PLIST_HEAD_INIT(cpu_latency_constraints.list),
+	.target_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.default_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.no_constraint_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE,
+	.type = PM_QOS_MIN,
+};
+
+/**
+ * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit.
+ */
+s32 cpu_latency_qos_limit(void)
+{
+	return pm_qos_read_value(&cpu_latency_constraints);
+}
+
+/**
+ * cpu_latency_qos_request_active - Check the given PM QoS request.
+ * @req: PM QoS request to check.
+ *
+ * Return: 'true' if @req has been added to the CPU latency QoS list, 'false'
+ * otherwise.
+ */
+bool cpu_latency_qos_request_active(struct pm_qos_request *req)
+{
+	return req->qos == &cpu_latency_constraints;
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_request_active);
+
+static void cpu_latency_qos_apply(struct pm_qos_request *req,
+				  enum pm_qos_req_action action, s32 value)
+{
+	int ret = pm_qos_update_target(req->qos, &req->node, action, value);
+	if (ret > 0)
+		wake_up_all_idle_cpus();
+}
+
+/**
+ * cpu_latency_qos_add_request - Add new CPU latency QoS request.
+ * @req: Pointer to a preallocated handle.
+ * @value: Requested constraint value.
+ *
+ * Use @value to initialize the request handle pointed to by @req, insert it as
+ * a new entry to the CPU latency QoS list and recompute the effective QoS
+ * constraint for that list.
+ *
+ * Callers need to save the handle for later use in updates and removal of the
+ * QoS request represented by it.
+ */
+void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value)
+{
+	if (!req)
+		return;
+
+	if (cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for already added request\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_add_request(value);
+
+	req->qos = &cpu_latency_constraints;
+	cpu_latency_qos_apply(req, PM_QOS_ADD_REQ, value);
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_add_request);
+
+/**
+ * cpu_latency_qos_update_request - Modify existing CPU latency QoS request.
+ * @req : QoS request to update.
+ * @new_value: New requested constraint value.
+ *
+ * Use @new_value to update the QoS request represented by @req in the CPU
+ * latency QoS list along with updating the effective constraint value for that
+ * list.
+ */
+void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value)
+{
+	if (!req)
+		return;
+
+	if (!cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for unknown object\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_update_request(new_value);
+
+	if (new_value == req->node.prio)
+		return;
+
+	cpu_latency_qos_apply(req, PM_QOS_UPDATE_REQ, new_value);
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_update_request);
+
+/**
+ * cpu_latency_qos_remove_request - Remove existing CPU latency QoS request.
+ * @req: QoS request to remove.
+ *
+ * Remove the CPU latency QoS request represented by @req from the CPU latency
+ * QoS list along with updating the effective constraint value for that list.
+ */
+void cpu_latency_qos_remove_request(struct pm_qos_request *req)
+{
+	if (!req)
+		return;
+
+	if (!cpu_latency_qos_request_active(req)) {
+		WARN(1, KERN_ERR "%s called for unknown object\n", __func__);
+		return;
+	}
+
+	trace_pm_qos_remove_request(PM_QOS_DEFAULT_VALUE);
+
+	cpu_latency_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
+	memset(req, 0, sizeof(*req));
+}
+EXPORT_SYMBOL_GPL(cpu_latency_qos_remove_request);
+
+/* User space interface to the CPU latency QoS via misc device. */
+
+static int cpu_latency_qos_open(struct inode *inode, struct file *filp)
+{
+	struct pm_qos_request *req;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	cpu_latency_qos_add_request(req, PM_QOS_DEFAULT_VALUE);
+	filp->private_data = req;
+
+	return 0;
+}
+
+static int cpu_latency_qos_release(struct inode *inode, struct file *filp)
+{
+	struct pm_qos_request *req = filp->private_data;
+
+	filp->private_data = NULL;
+
+	cpu_latency_qos_remove_request(req);
+	kfree(req);
+
+	return 0;
+}
+
+static ssize_t cpu_latency_qos_read(struct file *filp, char __user *buf,
+				    size_t count, loff_t *f_pos)
+{
+	struct pm_qos_request *req = filp->private_data;
+	unsigned long flags;
+	s32 value;
+
+	if (!req || !cpu_latency_qos_request_active(req))
+		return -EINVAL;
+
+	spin_lock_irqsave(&pm_qos_lock, flags);
+	value = pm_qos_get_value(&cpu_latency_constraints);
+	spin_unlock_irqrestore(&pm_qos_lock, flags);
+
+	return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32));
+}
+
+static ssize_t cpu_latency_qos_write(struct file *filp, const char __user *buf,
+				     size_t count, loff_t *f_pos)
+{
+	s32 value;
+
+	if (count == sizeof(s32)) {
+		if (copy_from_user(&value, buf, sizeof(s32)))
+			return -EFAULT;
+	} else {
+		int ret;
+
+		ret = kstrtos32_from_user(buf, count, 16, &value);
+		if (ret)
+			return ret;
+	}
+
+	cpu_latency_qos_update_request(filp->private_data, value);
+
+	return count;
+}
+
+static const struct file_operations cpu_latency_qos_fops = {
+	.write = cpu_latency_qos_write,
+	.read = cpu_latency_qos_read,
+	.open = cpu_latency_qos_open,
+	.release = cpu_latency_qos_release,
+	.llseek = noop_llseek,
+};
+
+static struct miscdevice cpu_latency_qos_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "cpu_dma_latency",
+	.fops = &cpu_latency_qos_fops,
+};
+
+static int __init cpu_latency_qos_init(void)
+{
+	int ret;
+
+	ret = misc_register(&cpu_latency_qos_miscdev);
+	if (ret < 0)
+		pr_err("%s: %s setup failed\n", __func__,
+		       cpu_latency_qos_miscdev.name);
+
+	return ret;
+}
+late_initcall(cpu_latency_qos_init);
+#endif /* CONFIG_CPU_IDLE */
+
+/* Definitions related to the frequency QoS below. */
+
+/**
+ * freq_constraints_init - Initialize frequency QoS constraints.
+ * @qos: Frequency QoS constraints to initialize.
+ */
+void freq_constraints_init(struct freq_constraints *qos)
+{
+	struct pm_qos_constraints *c;
+
+	c = &qos->min_freq;
+	plist_head_init(&c->list);
+	c->target_value = FREQ_QOS_MIN_DEFAULT_VALUE;
+	c->default_value = FREQ_QOS_MIN_DEFAULT_VALUE;
+	c->no_constraint_value = FREQ_QOS_MIN_DEFAULT_VALUE;
+	c->type = PM_QOS_MAX;
+	c->notifiers = &qos->min_freq_notifiers;
+	BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);
+
+	c = &qos->max_freq;
+	plist_head_init(&c->list);
+	c->target_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	c->default_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	c->no_constraint_value = FREQ_QOS_MAX_DEFAULT_VALUE;
+	c->type = PM_QOS_MIN;
+	c->notifiers = &qos->max_freq_notifiers;
+	BLOCKING_INIT_NOTIFIER_HEAD(c->notifiers);
+}
+
+/**
+ * freq_qos_read_value - Get frequency QoS constraint for a given list.
+ * @qos: Constraints to evaluate.
+ * @type: QoS request type.
+ */
+s32 freq_qos_read_value(struct freq_constraints *qos,
+			enum freq_qos_req_type type)
+{
+	s32 ret;
+
+	switch (type) {
+	case FREQ_QOS_MIN:
+		ret = IS_ERR_OR_NULL(qos) ?
+			FREQ_QOS_MIN_DEFAULT_VALUE :
+			pm_qos_read_value(&qos->min_freq);
+		break;
+	case FREQ_QOS_MAX:
+		ret = IS_ERR_OR_NULL(qos) ?
+			FREQ_QOS_MAX_DEFAULT_VALUE :
+			pm_qos_read_value(&qos->max_freq);
+		break;
+	default:
+		WARN_ON(1);
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/**
+ * freq_qos_apply - Add/modify/remove frequency QoS request.
+ * @req: Constraint request to apply.
+ * @action: Action to perform (add/update/remove).
+ * @value: Value to assign to the QoS request.
+ *
+ * This is only meant to be called from inside pm_qos, not drivers.
+ */
+int freq_qos_apply(struct freq_qos_request *req,
+			  enum pm_qos_req_action action, s32 value)
+{
+	int ret;
+
+	switch(req->type) {
+	case FREQ_QOS_MIN:
+		ret = pm_qos_update_target(&req->qos->min_freq, &req->pnode,
+					   action, value);
+		break;
+	case FREQ_QOS_MAX:
+		ret = pm_qos_update_target(&req->qos->max_freq, &req->pnode,
+					   action, value);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/**
+ * freq_qos_add_request - Insert new frequency QoS request into a given list.
+ * @qos: Constraints to update.
+ * @req: Preallocated request object.
+ * @type: Request type.
+ * @value: Request value.
+ *
+ * Insert a new entry into the @qos list of requests, recompute the effective
+ * QoS constraint value for that list and initialize the @req object.  The
+ * caller needs to save that object for later use in updates and removal.
+ *
+ * Return 1 if the effective constraint value has changed, 0 if the effective
+ * constraint value has not changed, or a negative error code on failures.
+ */
+int freq_qos_add_request(struct freq_constraints *qos,
+			 struct freq_qos_request *req,
+			 enum freq_qos_req_type type, s32 value)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(qos) || !req)
+		return -EINVAL;
+
+	if (WARN(freq_qos_request_active(req),
+		 "%s() called for active request\n", __func__))
+		return -EINVAL;
+
+	req->qos = qos;
+	req->type = type;
+	ret = freq_qos_apply(req, PM_QOS_ADD_REQ, value);
+	if (ret < 0) {
+		req->qos = NULL;
+		req->type = 0;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_add_request);
+
+/**
+ * freq_qos_update_request - Modify existing frequency QoS request.
+ * @req: Request to modify.
+ * @new_value: New request value.
+ *
+ * Update an existing frequency QoS request along with the effective constraint
+ * value for the list of requests it belongs to.
+ *
+ * Return 1 if the effective constraint value has changed, 0 if the effective
+ * constraint value has not changed, or a negative error code on failures.
+ */
+int freq_qos_update_request(struct freq_qos_request *req, s32 new_value)
+{
+	if (!req)
+		return -EINVAL;
+
+	if (WARN(!freq_qos_request_active(req),
+		 "%s() called for unknown object\n", __func__))
+		return -EINVAL;
+
+	if (req->pnode.prio == new_value)
+		return 0;
+
+	return freq_qos_apply(req, PM_QOS_UPDATE_REQ, new_value);
+}
+EXPORT_SYMBOL_GPL(freq_qos_update_request);
+
+/**
+ * freq_qos_remove_request - Remove frequency QoS request from its list.
+ * @req: Request to remove.
+ *
+ * Remove the given frequency QoS request from the list of constraints it
+ * belongs to and recompute the effective constraint value for that list.
+ *
+ * Return 1 if the effective constraint value has changed, 0 if the effective
+ * constraint value has not changed, or a negative error code on failures.
+ */
+int freq_qos_remove_request(struct freq_qos_request *req)
+{
+	int ret;
+
+	if (!req)
+		return -EINVAL;
+
+	if (WARN(!freq_qos_request_active(req),
+		 "%s() called for unknown object\n", __func__))
+		return -EINVAL;
+
+	ret = freq_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE);
+	req->qos = NULL;
+	req->type = 0;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_remove_request);
+
+/**
+ * freq_qos_add_notifier - Add frequency QoS change notifier.
+ * @qos: List of requests to add the notifier to.
+ * @type: Request type.
+ * @notifier: Notifier block to add.
+ */
+int freq_qos_add_notifier(struct freq_constraints *qos,
+			  enum freq_qos_req_type type,
+			  struct notifier_block *notifier)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(qos) || !notifier)
+		return -EINVAL;
+
+	switch (type) {
+	case FREQ_QOS_MIN:
+		ret = blocking_notifier_chain_register(qos->min_freq.notifiers,
+						       notifier);
+		break;
+	case FREQ_QOS_MAX:
+		ret = blocking_notifier_chain_register(qos->max_freq.notifiers,
+						       notifier);
+		break;
+	default:
+		WARN_ON(1);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_add_notifier);
+
+/**
+ * freq_qos_remove_notifier - Remove frequency QoS change notifier.
+ * @qos: List of requests to remove the notifier from.
+ * @type: Request type.
+ * @notifier: Notifier block to remove.
+ */
+int freq_qos_remove_notifier(struct freq_constraints *qos,
+			     enum freq_qos_req_type type,
+			     struct notifier_block *notifier)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(qos) || !notifier)
+		return -EINVAL;
+
+	switch (type) {
+	case FREQ_QOS_MIN:
+		ret = blocking_notifier_chain_unregister(qos->min_freq.notifiers,
+							 notifier);
+		break;
+	case FREQ_QOS_MAX:
+		ret = blocking_notifier_chain_unregister(qos->max_freq.notifiers,
+							 notifier);
+		break;
+	default:
+		WARN_ON(1);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(freq_qos_remove_notifier);