From: Cho KyongHo <pullip.cho@samsung.com>
To: Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>,
Linux DeviceTree <devicetree@vger.kernel.org>,
Linux IOMMU <iommu@lists.linux-foundation.org>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Linux Samsung SOC <linux-samsung-soc@vger.kernel.org>
Cc: Antonios Motakis <a.motakis@virtualopensystems.com>,
Grant Grundler <grundler@chromium.org>,
Joerg Roedel <joro@8bytes.org>,
Kukjin Kim <kgene.kim@samsung.com>,
Prathyush <prathyush.k@samsung.com>,
Rahul Sharma <rahul.sharma@samsung.com>,
Sachin Kamat <sachin.kamat@linaro.org>,
Subash Patel <supash.ramaswamy@linaro.org>,
Varun Sethi <Varun.Sethi@freescale.com>,
Sylwester Nawrocki <s.nawrocki@samsung.com>,
Tomasz Figa <t.figa@samsung.com>
Subject: [PATCH v10 18/20] iommu/exynos: change rwlock to spinlock
Date: Mon, 07 Oct 2013 10:58:18 +0900 [thread overview]
Message-ID: <20131007105818.916595496f5fa52c5bf372bf@samsung.com> (raw)
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@chromium.org>
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
---
drivers/iommu/exynos-iommu.c | 35 ++++++++++++++++++-----------------
1 files changed, 18 insertions(+), 17 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index e48c2fb..26ba554 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -183,7 +183,7 @@ struct sysmmu_drvdata {
struct clk *clk;
struct clk *clk_master;
int activations;
- rwlock_t lock;
+ spinlock_t lock;
struct iommu_domain *domain;
bool runtime_active;
unsigned long pgtable;
@@ -298,11 +298,12 @@ 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));
clk_enable(data->clk_master);
+
+ spin_lock(&data->lock);
+
itype = (enum exynos_sysmmu_inttype)
__ffs(__raw_readl(data->sfrbase + REG_INT_STATUS));
if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
@@ -335,7 +336,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
clk_disable(data->clk_master);
- read_unlock(&data->lock);
+ spin_unlock(&data->lock);
return IRQ_HANDLED;
}
@@ -356,7 +357,7 @@ 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);
@@ -373,7 +374,7 @@ static bool __sysmmu_disable(struct sysmmu_drvdata *data)
data->activations);
}
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
return disabled;
}
@@ -421,7 +422,7 @@ 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;
@@ -439,7 +440,7 @@ 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;
}
@@ -503,7 +504,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
data = dev_get_drvdata(client->sysmmu);
- read_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data) && data->runtime_active) {
unsigned int num_inv = 1;
/*
@@ -526,7 +527,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
dev_dbg(dev, "disabled. Skipping TLB invalidation @ %#lx\n",
iova);
}
- read_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
void exynos_sysmmu_tlb_invalidate(struct device *dev)
@@ -537,7 +538,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
data = dev_get_drvdata(client->sysmmu);
- read_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data) && data->runtime_active) {
clk_enable(data->clk_master);
if (sysmmu_block(data->sfrbase)) {
@@ -548,7 +549,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
} else {
dev_dbg(dev, "disabled. Skipping TLB invalidation\n");
}
- read_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
static int __init exynos_sysmmu_probe(struct platform_device *pdev)
@@ -609,7 +610,7 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
}
data->sysmmu = dev;
- rwlock_init(&data->lock);
+ spin_lock_init(&data->lock);
platform_set_drvdata(pdev, data);
@@ -625,11 +626,11 @@ static int sysmmu_suspend(struct device *dev)
{
struct sysmmu_drvdata *data = dev_get_drvdata(dev);
unsigned long flags;
- read_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data) &&
(!pm_runtime_enabled(dev) || data->runtime_active))
__sysmmu_disable_nocount(data);
- read_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
@@ -637,11 +638,11 @@ static int sysmmu_resume(struct device *dev)
{
struct sysmmu_drvdata *data = dev_get_drvdata(dev);
unsigned long flags;
- read_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (is_sysmmu_active(data) &&
(!pm_runtime_enabled(dev) || data->runtime_active))
__sysmmu_enable_nocount(data);
- read_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
#endif
--
1.7.2.5
reply other threads:[~2013-10-07 1:58 UTC|newest]
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