Since acquiring read_lock is not more frequent than write_lock, it is
not beneficial to use rwlock, this commit changes rwlock to spinlock.
Signed-off-by: Cho KyongHo <[email protected]>
---
drivers/iommu/exynos-iommu.c | 32 ++++++++++++++++----------------
1 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 390f8b7..6793661 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -175,7 +175,7 @@ struct sysmmu_drvdata {
void __iomem **sfrbases;
struct clk *clk[2];
int activations;
- rwlock_t lock;
+ spinlock_t lock;
struct iommu_domain *domain;
sysmmu_fault_handler_t fault_handler;
unsigned long pgtable;
@@ -259,7 +259,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
BUG_ON((base0 + size0) <= base0);
BUG_ON((size1 > 0) && ((base1 + size1) <= base1));
- read_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (!is_sysmmu_active(data))
goto finish;
@@ -289,7 +289,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
}
}
finish:
- read_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
static void __set_fault_handler(struct sysmmu_drvdata *data,
@@ -297,9 +297,9 @@ static void __set_fault_handler(struct sysmmu_drvdata *data,
{
unsigned long flags;
- write_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
data->fault_handler = handler;
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
void exynos_sysmmu_set_fault_handler(struct device *dev,
@@ -347,7 +347,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
int i, ret = -ENOSYS;
- read_lock(&data->lock);
+ spin_lock(&data->lock);
WARN_ON(!is_sysmmu_active(data));
@@ -391,7 +391,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
if (itype != SYSMMU_FAULT_UNKNOWN)
sysmmu_unblock(data->sfrbases[i]);
- read_unlock(&data->lock);
+ spin_unlock(&data->lock);
return IRQ_HANDLED;
}
@@ -402,7 +402,7 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
bool disabled = false;
int i;
- write_lock_irqsave(&data->lock, flags);
+ spin_lock_irqsave(&data->lock, flags);
if (!set_sysmmu_inactive(data))
goto finish;
@@ -419,7 +419,7 @@ 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, "(%s) Disabled\n", data->dbgname);
@@ -442,7 +442,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
int i, 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)) {
@@ -481,7 +481,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
finish:
- write_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
return ret;
}
@@ -528,7 +528,7 @@ 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)) {
int i;
@@ -545,7 +545,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
data->dbgname);
}
- read_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
void exynos_sysmmu_tlb_invalidate(struct device *dev)
@@ -553,7 +553,7 @@ 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)) {
int i;
@@ -569,7 +569,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
data->dbgname);
}
- read_unlock_irqrestore(&data->lock, flags);
+ spin_unlock_irqrestore(&data->lock, flags);
}
static int exynos_sysmmu_probe(struct platform_device *pdev)
@@ -666,7 +666,7 @@ 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);
__set_fault_handler(data, &default_fault_handler);
--
1.7.2.5
Hi,
On Friday, July 05, 2013 09:29:26 PM Cho KyongHo wrote:
> Since acquiring read_lock is not more frequent than write_lock, it is
> not beneficial to use rwlock, this commit changes rwlock to spinlock.
This change is not of a "fix type" and is not required to make the driver
work so it would probably be best to move it to the end of a patch series
(IOW just making it the last patch in the series).
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
> Signed-off-by: Cho KyongHo <[email protected]>
> ---
> drivers/iommu/exynos-iommu.c | 32 ++++++++++++++++----------------
> 1 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index 390f8b7..6793661 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -175,7 +175,7 @@ struct sysmmu_drvdata {
> void __iomem **sfrbases;
> struct clk *clk[2];
> int activations;
> - rwlock_t lock;
> + spinlock_t lock;
> struct iommu_domain *domain;
> sysmmu_fault_handler_t fault_handler;
> unsigned long pgtable;
> @@ -259,7 +259,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
> BUG_ON((base0 + size0) <= base0);
> BUG_ON((size1 > 0) && ((base1 + size1) <= base1));
>
> - read_lock_irqsave(&data->lock, flags);
> + spin_lock_irqsave(&data->lock, flags);
> if (!is_sysmmu_active(data))
> goto finish;
>
> @@ -289,7 +289,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
> }
> }
> finish:
> - read_unlock_irqrestore(&data->lock, flags);
> + spin_unlock_irqrestore(&data->lock, flags);
> }
>
> static void __set_fault_handler(struct sysmmu_drvdata *data,
> @@ -297,9 +297,9 @@ static void __set_fault_handler(struct sysmmu_drvdata *data,
> {
> unsigned long flags;
>
> - write_lock_irqsave(&data->lock, flags);
> + spin_lock_irqsave(&data->lock, flags);
> data->fault_handler = handler;
> - write_unlock_irqrestore(&data->lock, flags);
> + spin_unlock_irqrestore(&data->lock, flags);
> }
>
> void exynos_sysmmu_set_fault_handler(struct device *dev,
> @@ -347,7 +347,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
>
> int i, ret = -ENOSYS;
>
> - read_lock(&data->lock);
> + spin_lock(&data->lock);
>
> WARN_ON(!is_sysmmu_active(data));
>
> @@ -391,7 +391,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
> if (itype != SYSMMU_FAULT_UNKNOWN)
> sysmmu_unblock(data->sfrbases[i]);
>
> - read_unlock(&data->lock);
> + spin_unlock(&data->lock);
>
> return IRQ_HANDLED;
> }
> @@ -402,7 +402,7 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
> bool disabled = false;
> int i;
>
> - write_lock_irqsave(&data->lock, flags);
> + spin_lock_irqsave(&data->lock, flags);
>
> if (!set_sysmmu_inactive(data))
> goto finish;
> @@ -419,7 +419,7 @@ 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, "(%s) Disabled\n", data->dbgname);
> @@ -442,7 +442,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
> int i, 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)) {
> @@ -481,7 +481,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
>
> dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
> finish:
> - write_unlock_irqrestore(&data->lock, flags);
> + spin_unlock_irqrestore(&data->lock, flags);
>
> return ret;
> }
> @@ -528,7 +528,7 @@ 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)) {
> int i;
> @@ -545,7 +545,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
> data->dbgname);
> }
>
> - read_unlock_irqrestore(&data->lock, flags);
> + spin_unlock_irqrestore(&data->lock, flags);
> }
>
> void exynos_sysmmu_tlb_invalidate(struct device *dev)
> @@ -553,7 +553,7 @@ 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)) {
> int i;
> @@ -569,7 +569,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
> data->dbgname);
> }
>
> - read_unlock_irqrestore(&data->lock, flags);
> + spin_unlock_irqrestore(&data->lock, flags);
> }
>
> static int exynos_sysmmu_probe(struct platform_device *pdev)
> @@ -666,7 +666,7 @@ 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);
>
> __set_fault_handler(data, &default_fault_handler);
> From: Bartlomiej Zolnierkiewicz [mailto:[email protected]]
> Sent: Saturday, July 13, 2013 12:31 AM
>
> Hi,
>
> On Friday, July 05, 2013 09:29:26 PM Cho KyongHo wrote:
> > Since acquiring read_lock is not more frequent than write_lock, it is
> > not beneficial to use rwlock, this commit changes rwlock to spinlock.
>
> This change is not of a "fix type" and is not required to make the driver
> work so it would probably be best to move it to the end of a patch series
> (IOW just making it the last patch in the series).
>
Thank you for advice.
I will do that in the next patchset :)
Cho KyongHo.
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics
>
> > Signed-off-by: Cho KyongHo <[email protected]>
> > ---
> > drivers/iommu/exynos-iommu.c | 32 ++++++++++++++++----------------
> > 1 files changed, 16 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> > index 390f8b7..6793661 100644
> > --- a/drivers/iommu/exynos-iommu.c
> > +++ b/drivers/iommu/exynos-iommu.c
> > @@ -175,7 +175,7 @@ struct sysmmu_drvdata {
> > void __iomem **sfrbases;
> > struct clk *clk[2];
> > int activations;
> > - rwlock_t lock;
> > + spinlock_t lock;
> > struct iommu_domain *domain;
> > sysmmu_fault_handler_t fault_handler;
> > unsigned long pgtable;
> > @@ -259,7 +259,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
> > BUG_ON((base0 + size0) <= base0);
> > BUG_ON((size1 > 0) && ((base1 + size1) <= base1));
> >
> > - read_lock_irqsave(&data->lock, flags);
> > + spin_lock_irqsave(&data->lock, flags);
> > if (!is_sysmmu_active(data))
> > goto finish;
> >
> > @@ -289,7 +289,7 @@ void exynos_sysmmu_set_prefbuf(struct device *dev,
> > }
> > }
> > finish:
> > - read_unlock_irqrestore(&data->lock, flags);
> > + spin_unlock_irqrestore(&data->lock, flags);
> > }
> >
> > static void __set_fault_handler(struct sysmmu_drvdata *data,
> > @@ -297,9 +297,9 @@ static void __set_fault_handler(struct sysmmu_drvdata *data,
> > {
> > unsigned long flags;
> >
> > - write_lock_irqsave(&data->lock, flags);
> > + spin_lock_irqsave(&data->lock, flags);
> > data->fault_handler = handler;
> > - write_unlock_irqrestore(&data->lock, flags);
> > + spin_unlock_irqrestore(&data->lock, flags);
> > }
> >
> > void exynos_sysmmu_set_fault_handler(struct device *dev,
> > @@ -347,7 +347,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
> >
> > int i, ret = -ENOSYS;
> >
> > - read_lock(&data->lock);
> > + spin_lock(&data->lock);
> >
> > WARN_ON(!is_sysmmu_active(data));
> >
> > @@ -391,7 +391,7 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
> > if (itype != SYSMMU_FAULT_UNKNOWN)
> > sysmmu_unblock(data->sfrbases[i]);
> >
> > - read_unlock(&data->lock);
> > + spin_unlock(&data->lock);
> >
> > return IRQ_HANDLED;
> > }
> > @@ -402,7 +402,7 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
> > bool disabled = false;
> > int i;
> >
> > - write_lock_irqsave(&data->lock, flags);
> > + spin_lock_irqsave(&data->lock, flags);
> >
> > if (!set_sysmmu_inactive(data))
> > goto finish;
> > @@ -419,7 +419,7 @@ 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, "(%s) Disabled\n", data->dbgname);
> > @@ -442,7 +442,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
> > int i, 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)) {
> > @@ -481,7 +481,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
> >
> > dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
> > finish:
> > - write_unlock_irqrestore(&data->lock, flags);
> > + spin_unlock_irqrestore(&data->lock, flags);
> >
> > return ret;
> > }
> > @@ -528,7 +528,7 @@ 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)) {
> > int i;
> > @@ -545,7 +545,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
> > data->dbgname);
> > }
> >
> > - read_unlock_irqrestore(&data->lock, flags);
> > + spin_unlock_irqrestore(&data->lock, flags);
> > }
> >
> > void exynos_sysmmu_tlb_invalidate(struct device *dev)
> > @@ -553,7 +553,7 @@ 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)) {
> > int i;
> > @@ -569,7 +569,7 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
> > data->dbgname);
> > }
> >
> > - read_unlock_irqrestore(&data->lock, flags);
> > + spin_unlock_irqrestore(&data->lock, flags);
> > }
> >
> > static int exynos_sysmmu_probe(struct platform_device *pdev)
> > @@ -666,7 +666,7 @@ 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);
> >
> > __set_fault_handler(data, &default_fault_handler);