From: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
Since acquiring read_lock is not more frequent than write_lock, it is
not beneficial to use rwlock, this commit changes rwlock to spinlock.
Reviewed-by: Grant Grundler <grundler@xxxxxxxxxxxx>
Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 39 ++++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index c2e6365..c9076e1 100755
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -200,7 +200,7 @@ struct sysmmu_drvdata {
struct clk *clk;
struct clk *clk_master;
int activations;
- rwlock_t lock;
+ spinlock_t lock;
struct iommu_domain *domain;
bool powered_on;
bool suspended;
@@ -323,12 +323,13 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
unsigned long addr = -1;
int ret = -ENOSYS;
- read_lock(&data->lock);
-
WARN_ON(!is_sysmmu_active(data));
+ spin_lock(&data->lock);
+
if (!IS_ERR(data->clk_master))
clk_enable(data->clk_master);
+
itype = (enum exynos_sysmmu_inttype)
__ffs(__raw_readl(data->sfrbase + REG_INT_STATUS));
if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
@@ -362,7 +363,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
if (!IS_ERR(data->clk_master))
clk_disable(data->clk_master);
- read_unlock(&data->lock);
+ spin_unlock(&data->lock);
return IRQ_HANDLED;
}
@@ -385,7 +386,7 @@ static bool __sysmmu_disable(struct sysmmu_drvdata *data)
bool disabled;
unsigned long flags;
- write_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
disabled = set_sysmmu_inactive(data);
@@ -402,7 +403,7 @@ static bool __sysmmu_disable(struct sysmmu_drvdata *data)
data->activations);
}
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
return disabled;
}
@@ -452,7 +453,7 @@ static int __sysmmu_enable(struct sysmmu_drvdata *data,
int ret = 0;
unsigned long flags;
- write_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (set_sysmmu_active(data)) {
data->pgtable = pgtable;
data->domain = domain;
@@ -470,7 +471,7 @@ static int __sysmmu_enable(struct sysmmu_drvdata *data,
if (WARN_ON(ret < 0))
set_sysmmu_inactive(data); /* decrement count */
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
return ret;
}
@@ -557,7 +558,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
for_each_sysmmu_list(dev, list) {
struct sysmmu_drvdata *data = dev_get_drvdata(list->sysmmu);
- read_lock(&data->lock);
+ spin_lock(&data->lock);
if (is_sysmmu_active(data) && data->powered_on) {
unsigned int num_inv = 1;
@@ -592,7 +593,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
iova);
}
- read_unlock(&data->lock);
+ spin_unlock(&data->lock);
}
spin_unlock_irqrestore(&owner->lock, flags);
@@ -608,7 +609,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
for_each_sysmmu_list(dev, list) {
struct sysmmu_drvdata *data = dev_get_drvdata(list->sysmmu);
- read_lock(&data->lock);
+ spin_lock(&data->lock);
if (is_sysmmu_active(data) && data->powered_on) {
if (!IS_ERR(data->clk_master))
clk_enable(data->clk_master);
@@ -621,7 +622,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
} else {
dev_dbg(dev, "disabled. Skipping TLB invalidation\n");
}
- read_unlock(&data->lock);
+ spin_unlock(&data->lock);
}
spin_unlock_irqrestore(&owner->lock, flags);
@@ -813,7 +814,7 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
if (!ret) {
data->powered_on = !pm_runtime_enabled(dev);
data->sysmmu = dev;
- rwlock_init(&data->lock);
+ spin_lock_init(&data->lock);
platform_set_drvdata(pdev, data);
}
@@ -1264,12 +1265,12 @@ static int sysmmu_pm_genpd_suspend(struct device *dev)
for_each_sysmmu_list(dev, list) {
struct sysmmu_drvdata *data = dev_get_drvdata(list->sysmmu);
unsigned long flags;
- write_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (!data->suspended && is_sysmmu_active(data) &&
(!pm_runtime_enabled(dev) || data->powered_on))
__sysmmu_disable_nocount(data);
data->suspended = true;
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
return 0;
@@ -1282,12 +1283,12 @@ static int sysmmu_pm_genpd_resume(struct device *dev)
for_each_sysmmu_list(dev, list) {
struct sysmmu_drvdata *data = dev_get_drvdata(list->sysmmu);
unsigned long flags;
- write_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (data->suspended && is_sysmmu_active(data) &&
(!pm_runtime_enabled(dev) || data->powered_on))
__sysmmu_enable_nocount(data);
data->suspended = false;
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
return pm_generic_resume(dev);
@@ -1439,12 +1440,12 @@ static int sysmmu_hook_driver_register(struct notifier_block *nb,
dev_get_drvdata(list->sysmmu);
unsigned long flags;
- write_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data) && !data->powered_on)
__sysmmu_enable_nocount(data);
data->powered_on = true;
pm_runtime_disable(data->sysmmu);
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
break;
}
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
