OMAP2+: clockdomain: Add per clkdm lock to prevent concurrent state programming

Since the clkdm state programming is now done from within the hwmod
framework (which uses a per-hwmod lock) instead of the being done
from the clock framework (which used a global lock), there is now a
need to have per-clkdm locking to prevent races between different
hwmods/modules belonging to the same clock domain concurrently
programming the clkdm state.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 40 insertions, 7 deletions

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 239b558853f..ab7db083f97 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -92,6 +92,8 @@ static int _clkdm_register(struct clockdomain *clkdm)
 
 	pwrdm_add_clkdm(pwrdm, clkdm);
 
+	spin_lock_init(&clkdm->lock);
+
 	pr_debug("clockdomain: registered %s\n", clkdm->name);
 
 	return 0;
@@ -690,6 +692,9 @@ int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
  */
 int clkdm_sleep(struct clockdomain *clkdm)
 {
+	int ret;
+	unsigned long flags;
+
 	if (!clkdm)
 		return -EINVAL;
 
@@ -704,9 +709,11 @@ int clkdm_sleep(struct clockdomain *clkdm)
 
 	pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
 
+	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
-
-	return arch_clkdm->clkdm_sleep(clkdm);
+	ret = arch_clkdm->clkdm_sleep(clkdm);
+	spin_unlock_irqrestore(&clkdm->lock, flags);
+	return ret;
 }
 
 /**
@@ -720,6 +727,9 @@ int clkdm_sleep(struct clockdomain *clkdm)
  */
 int clkdm_wakeup(struct clockdomain *clkdm)
 {
+	int ret;
+	unsigned long flags;
+
 	if (!clkdm)
 		return -EINVAL;
 
@@ -734,9 +744,11 @@ int clkdm_wakeup(struct clockdomain *clkdm)
 
 	pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
 
+	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
-
-	return arch_clkdm->clkdm_wakeup(clkdm);
+	ret = arch_clkdm->clkdm_wakeup(clkdm);
+	spin_unlock_irqrestore(&clkdm->lock, flags);
+	return ret;
 }
 
 /**
@@ -751,6 +763,8 @@ int clkdm_wakeup(struct clockdomain *clkdm)
  */
 void clkdm_allow_idle(struct clockdomain *clkdm)
 {
+	unsigned long flags;
+
 	if (!clkdm)
 		return;
 
@@ -766,10 +780,11 @@ void clkdm_allow_idle(struct clockdomain *clkdm)
 	pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
 		 clkdm->name);
 
+	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags |= _CLKDM_FLAG_HWSUP_ENABLED;
-
 	arch_clkdm->clkdm_allow_idle(clkdm);
 	pwrdm_clkdm_state_switch(clkdm);
+	spin_unlock_irqrestore(&clkdm->lock, flags);
 }
 
 /**
@@ -783,6 +798,8 @@ void clkdm_allow_idle(struct clockdomain *clkdm)
  */
 void clkdm_deny_idle(struct clockdomain *clkdm)
 {
+	unsigned long flags;
+
 	if (!clkdm)
 		return;
 
@@ -798,9 +815,10 @@ void clkdm_deny_idle(struct clockdomain *clkdm)
 	pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
 		 clkdm->name);
 
+	spin_lock_irqsave(&clkdm->lock, flags);
 	clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
-
 	arch_clkdm->clkdm_deny_idle(clkdm);
+	spin_unlock_irqrestore(&clkdm->lock, flags);
 }
 
 /**
@@ -816,16 +834,25 @@ void clkdm_deny_idle(struct clockdomain *clkdm)
  */
 bool clkdm_in_hwsup(struct clockdomain *clkdm)
 {
+	bool ret;
+	unsigned long flags;
+
 	if (!clkdm)
 		return false;
 
-	return (clkdm->_flags & _CLKDM_FLAG_HWSUP_ENABLED) ? true : false;
+	spin_lock_irqsave(&clkdm->lock, flags);
+	ret = (clkdm->_flags & _CLKDM_FLAG_HWSUP_ENABLED) ? true : false;
+	spin_unlock_irqrestore(&clkdm->lock, flags);
+
+	return ret;
 }
 
 /* Clockdomain-to-clock/hwmod framework interface code */
 
 static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
 {
+	unsigned long flags;
+
 	if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable)
 		return -EINVAL;
 
@@ -837,9 +864,11 @@ static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
 	if ((atomic_inc_return(&clkdm->usecount) > 1) && autodeps)
 		return 0;
 
+	spin_lock_irqsave(&clkdm->lock, flags);
 	arch_clkdm->clkdm_clk_enable(clkdm);
 	pwrdm_wait_transition(clkdm->pwrdm.ptr);
 	pwrdm_clkdm_state_switch(clkdm);
+	spin_unlock_irqrestore(&clkdm->lock, flags);
 
 	pr_debug("clockdomain: clkdm %s: enabled\n", clkdm->name);
 
@@ -848,6 +877,8 @@ static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
 
 static int _clkdm_clk_hwmod_disable(struct clockdomain *clkdm)
 {
+	unsigned long flags;
+
 	if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
 		return -EINVAL;
 
@@ -859,8 +890,10 @@ static int _clkdm_clk_hwmod_disable(struct clockdomain *clkdm)
 	if (atomic_dec_return(&clkdm->usecount) > 0)
 		return 0;
 
+	spin_lock_irqsave(&clkdm->lock, flags);
 	arch_clkdm->clkdm_clk_disable(clkdm);
 	pwrdm_clkdm_state_switch(clkdm);
+	spin_unlock_irqrestore(&clkdm->lock, flags);
 
 	pr_debug("clockdomain: clkdm %s: disabled\n", clkdm->name);