blogic pushed a commit to source.git, branch master:
https://git.lede-project.org/a154a3d8bec45339c5f4f20b9dc6987652c63e41
commit a154a3d8bec45339c5f4f20b9dc6987652c63e41
Author: Pavel Kubelun <be.dissent at gmail.com>
AuthorDate: Wed Nov 2 22:32:36 2016 +0300
ipq806x: add opp patches for voltage scaling
Preparing for cpufreq driver switch to generic cpufreq-dt
Signed-off-by: Pavel Kubelun <be.dissent at gmail.com>
---
...Support-adjusting-OPP-voltages-at-runtime.patch | 145 +++++++++++++++++++++
...call-dev_pm_opp_get_voltage-freq-RCU-free.patch | 114 ++++++++++++++++
2 files changed, 259 insertions(+)
diff --git a/target/linux/ipq806x/patches-4.4/169-OPP-Support-adjusting-OPP-voltages-at-runtime.patch b/target/linux/ipq806x/patches-4.4/169-OPP-Support-adjusting-OPP-voltages-at-runtime.patch
new file mode 100644
index 0000000..8f0afb5
--- /dev/null
+++ b/target/linux/ipq806x/patches-4.4/169-OPP-Support-adjusting-OPP-voltages-at-runtime.patch
@@ -0,0 +1,145 @@
+From 111139c943a082364fbbcd9e0cc94cd442481340 Mon Sep 17 00:00:00 2001
+From: Stephen Boyd <sboyd at codeaurora.org>
+Date: Mon, 1 Jun 2015 18:47:56 -0700
+Subject: PM / OPP: Support adjusting OPP voltages at runtime
+
+On some SoCs the Adaptive Voltage Scaling (AVS) technique is
+employed to optimize the operating voltage of a device. At a
+given frequency, the hardware monitors dynamic factors and either
+makes a suggestion for how much to adjust a voltage for the
+current frequency, or it automatically adjusts the voltage
+without software intervention. Add an API to the OPP library for
+the former case, so that AVS type devices can update the voltages
+for an OPP when the hardware determines the voltage should
+change. The assumption is that drivers like CPUfreq or devfreq
+will register for the OPP notifiers and adjust the voltage
+according to suggestions that AVS makes.
+
+Cc: Nishanth Menon <nm at ti.com>
+Cc: Viresh Kumar <viresh.kumar at linaro.org>
+Signed-off-by: Stephen Boyd <sboyd at codeaurora.org>
+Acked-by: Viresh Kumar <viresh.kumar at linaro.org>
+---
+ drivers/base/power/opp/core.c | 77 +++++++++++++++++++++++++++++++++++++++++++
+ include/linux/pm_opp.h | 10 ++++++
+ 2 files changed, 87 insertions(+)
+
+--- a/drivers/base/power/opp/core.c
++++ b/drivers/base/power/opp/core.c
+@@ -1039,6 +1039,83 @@ unlock:
+ }
+
+ /**
++ * dev_pm_opp_adjust_voltage() - helper to change the voltage of an opp
++ * @dev: device for which we do this operation
++ * @freq: OPP frequency to adjust voltage of
++ * @u_volt: new OPP voltage
++ *
++ * Change the voltage of an OPP with an RCU operation.
++ *
++ * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
++ * copy operation, returns 0 if no modifcation was done OR modification was
++ * successful.
++ *
++ * Locking: The internal device_opp and opp structures are RCU protected.
++ * Hence this function internally uses RCU updater strategy with mutex locks to
++ * keep the integrity of the internal data structures. Callers should ensure
++ * that this function is *NOT* called under RCU protection or in contexts where
++ * mutex locking or synchronize_rcu() blocking calls cannot be used.
++ */
++int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
++ unsigned long u_volt)
++{
++ struct device_opp *dev_opp;
++ struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV);
++ int r = 0;
++
++ /* keep the node allocated */
++ new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL);
++ if (!new_opp)
++ return -ENOMEM;
++
++ mutex_lock(&dev_opp_list_lock);
++
++ /* Find the device_opp */
++ dev_opp = _find_device_opp(dev);
++ if (IS_ERR(dev_opp)) {
++ r = PTR_ERR(dev_opp);
++ dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
++ goto unlock;
++ }
++
++ /* Do we have the frequency? */
++ list_for_each_entry(tmp_opp, &dev_opp->opp_list, node) {
++ if (tmp_opp->rate == freq) {
++ opp = tmp_opp;
++ break;
++ }
++ }
++ if (IS_ERR(opp)) {
++ r = PTR_ERR(opp);
++ goto unlock;
++ }
++
++ /* Is update really needed? */
++ if (opp->u_volt == u_volt)
++ goto unlock;
++ /* copy the old data over */
++ *new_opp = *opp;
++
++ /* plug in new node */
++ new_opp->u_volt = u_volt;
++
++ list_replace_rcu(&opp->node, &new_opp->node);
++ mutex_unlock(&dev_opp_list_lock);
++ call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
++
++ /* Notify the change of the OPP */
++ srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_ADJUST_VOLTAGE,
++ new_opp);
++
++ return 0;
++
++unlock:
++ mutex_unlock(&dev_opp_list_lock);
++ kfree(new_opp);
++ return r;
++}
++
++/**
+ * dev_pm_opp_enable() - Enable a specific OPP
+ * @dev: device for which we do this operation
+ * @freq: OPP frequency to enable
+--- a/include/linux/pm_opp.h
++++ b/include/linux/pm_opp.h
+@@ -22,6 +22,7 @@ struct device;
+
+ enum dev_pm_opp_event {
+ OPP_EVENT_ADD, OPP_EVENT_REMOVE, OPP_EVENT_ENABLE, OPP_EVENT_DISABLE,
++ OPP_EVENT_ADJUST_VOLTAGE,
+ };
+
+ #if defined(CONFIG_PM_OPP)
+@@ -50,6 +51,9 @@ int dev_pm_opp_add(struct device *dev, u
+ unsigned long u_volt);
+ void dev_pm_opp_remove(struct device *dev, unsigned long freq);
+
++int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
++ unsigned long u_volt);
++
+ int dev_pm_opp_enable(struct device *dev, unsigned long freq);
+
+ int dev_pm_opp_disable(struct device *dev, unsigned long freq);
+@@ -114,6 +118,12 @@ static inline void dev_pm_opp_remove(str
+ {
+ }
+
++static inline int dev_pm_opp_adjust_voltage(struct device *dev,
++ unsigned long freq, unsigned long u_volt)
++{
++ return 0;
++}
++
+ static inline int dev_pm_opp_enable(struct device *dev, unsigned long freq)
+ {
+ return 0;
diff --git a/target/linux/ipq806x/patches-4.4/170-OPP-Allow-notifiers-to-call-dev_pm_opp_get_voltage-freq-RCU-free.patch b/target/linux/ipq806x/patches-4.4/170-OPP-Allow-notifiers-to-call-dev_pm_opp_get_voltage-freq-RCU-free.patch
new file mode 100644
index 0000000..7be47a3
--- /dev/null
+++ b/target/linux/ipq806x/patches-4.4/170-OPP-Allow-notifiers-to-call-dev_pm_opp_get_voltage-freq-RCU-free.patch
@@ -0,0 +1,114 @@
+From d330eae026b4a73e77ca0422f5cae5207d80f738 Mon Sep 17 00:00:00 2001
+From: Stephen Boyd <sboyd at codeaurora.org>
+Date: Mon, 1 Jun 2015 18:47:57 -0700
+Subject: OPP: Allow notifiers to call dev_pm_opp_get_{voltage, freq} RCU-free
+
+We pass the dev_pm_opp structure to OPP notifiers but the users
+of the notifier need to surround calls to dev_pm_opp_get_*() with
+RCU read locks to avoid lockdep warnings. The notifier is already
+called with the dev_opp's srcu lock held, so it should be safe to
+assume the devm_pm_opp structure is already protected inside the
+notifier. Update the lockdep check for this.
+
+Cc: Krzysztof Kozlowski <k.kozlowski at samsung.com>
+Signed-off-by: Stephen Boyd <sboyd at codeaurora.org>
+---
+ drivers/base/power/opp/core.c | 27 +++++++++++++++------------
+ 1 file changed, 15 insertions(+), 12 deletions(-)
+
+--- a/drivers/base/power/opp/core.c
++++ b/drivers/base/power/opp/core.c
+@@ -31,9 +31,10 @@ static LIST_HEAD(dev_opp_list);
+ /* Lock to allow exclusive modification to the device and opp lists */
+ DEFINE_MUTEX(dev_opp_list_lock);
+
+-#define opp_rcu_lockdep_assert() \
++#define opp_rcu_lockdep_assert(s) \
+ do { \
+ RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
++ !(s && srcu_read_lock_held(s)) && \
+ !lockdep_is_held(&dev_opp_list_lock), \
+ "Missing rcu_read_lock() or " \
+ "dev_opp_list_lock protection"); \
+@@ -91,7 +92,7 @@ struct device_opp *_find_device_opp(stru
+ {
+ struct device_opp *dev_opp;
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(NULL);
+
+ if (IS_ERR_OR_NULL(dev)) {
+ pr_err("%s: Invalid parameters\n", __func__);
+@@ -125,10 +126,11 @@ unsigned long dev_pm_opp_get_voltage(str
+ struct dev_pm_opp *tmp_opp;
+ unsigned long v = 0;
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(&opp->dev_opp->srcu_head.srcu);
+
+- tmp_opp = rcu_dereference(opp);
+- if (IS_ERR_OR_NULL(tmp_opp))
++ tmp_opp = srcu_dereference_check(opp, &opp->dev_opp->srcu_head.srcu,
++ rcu_read_lock_held());
++ if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available)
+ pr_err("%s: Invalid parameters\n", __func__);
+ else
+ v = tmp_opp->u_volt;
+@@ -157,9 +159,10 @@ unsigned long dev_pm_opp_get_freq(struct
+ struct dev_pm_opp *tmp_opp;
+ unsigned long f = 0;
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(&opp->dev_opp->srcu_head.srcu);
+
+- tmp_opp = rcu_dereference(opp);
++ tmp_opp = srcu_dereference_check(opp, &opp->dev_opp->srcu_head.srcu,
++ rcu_read_lock_held());
+ if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available)
+ pr_err("%s: Invalid parameters\n", __func__);
+ else
+@@ -191,7 +194,7 @@ bool dev_pm_opp_is_turbo(struct dev_pm_o
+ {
+ struct dev_pm_opp *tmp_opp;
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(&opp->dev_opp->srcu_head.srcu);
+
+ tmp_opp = rcu_dereference(opp);
+ if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) {
+@@ -246,7 +249,7 @@ struct dev_pm_opp *dev_pm_opp_get_suspen
+ {
+ struct device_opp *dev_opp;
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(NULL);
+
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp) || !dev_opp->suspend_opp ||
+@@ -326,7 +329,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
+ struct device_opp *dev_opp;
+ struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(NULL);
+
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp)) {
+@@ -374,7 +377,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
+ struct device_opp *dev_opp;
+ struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(NULL);
+
+ if (!dev || !freq) {
+ dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
+@@ -424,7 +427,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_
+ struct device_opp *dev_opp;
+ struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+- opp_rcu_lockdep_assert();
++ opp_rcu_lockdep_assert(NULL);
+
+ if (!dev || !freq) {
+ dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);