From 9d4e7a24d77a05fb5c4e4121051a8d80501c74d3 Mon Sep 17 00:00:00 2001 From: Cho KyongHo Date: Mon, 12 May 2014 11:44:57 +0530 Subject: [PATCH] iommu/exynos: Change rwlock to spinlock 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 Signed-off-by: Cho KyongHo Signed-off-by: Shaik Ameer Basha Signed-off-by: Joerg Roedel --- drivers/iommu/exynos-iommu.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index c1be65fd0af5..d89ad5f8747c 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -164,7 +164,7 @@ struct sysmmu_drvdata { struct clk *clk; struct clk *clk_master; int activations; - rwlock_t lock; + spinlock_t lock; struct iommu_domain *domain; phys_addr_t pgtable; }; @@ -263,12 +263,13 @@ 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)))) @@ -302,7 +303,7 @@ 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; } @@ -312,7 +313,7 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data) unsigned long flags; bool disabled = false; - write_lock_irqsave(&data->lock, flags); + spin_lock_irqsave(&data->lock, flags); if (!set_sysmmu_inactive(data)) goto finish; @@ -330,7 +331,7 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data) data->pgtable = 0; data->domain = NULL; finish: - write_unlock_irqrestore(&data->lock, flags); + spin_unlock_irqrestore(&data->lock, flags); if (disabled) dev_dbg(data->sysmmu, "Disabled\n"); @@ -353,7 +354,7 @@ static int __exynos_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)) { if (WARN_ON(pgtable != data->pgtable)) { @@ -384,7 +385,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data, dev_dbg(data->sysmmu, "Enabled\n"); finish: - write_unlock_irqrestore(&data->lock, flags); + spin_unlock_irqrestore(&data->lock, flags); return ret; } @@ -431,7 +432,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova, unsigned long flags; struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu); - read_lock_irqsave(&data->lock, flags); + spin_lock_irqsave(&data->lock, flags); if (is_sysmmu_active(data)) { unsigned int maj; @@ -465,7 +466,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova, dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n"); } - read_unlock_irqrestore(&data->lock, flags); + spin_unlock_irqrestore(&data->lock, flags); } void exynos_sysmmu_tlb_invalidate(struct device *dev) @@ -473,7 +474,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev) unsigned long flags; struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu); - read_lock_irqsave(&data->lock, flags); + spin_lock_irqsave(&data->lock, flags); if (is_sysmmu_active(data)) { if (!IS_ERR(data->clk_master)) @@ -488,7 +489,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev) dev_dbg(data->sysmmu, "Disabled. Skipping invalidating TLB.\n"); } - read_unlock_irqrestore(&data->lock, flags); + spin_unlock_irqrestore(&data->lock, flags); } static int exynos_sysmmu_probe(struct platform_device *pdev) @@ -543,7 +544,7 @@ static int exynos_sysmmu_probe(struct platform_device *pdev) } data->sysmmu = dev; - rwlock_init(&data->lock); + spin_lock_init(&data->lock); INIT_LIST_HEAD(&data->node); platform_set_drvdata(pdev, data); -- 2.34.1