[PATCH v3 0/7] Improve tlb range flush

[PATCH v3 0/7] Improve tlb range flush

[Yong Wu]

This patchset mainly fixes a tlb flush timeout issue and use the new
iommu_gather to re-implement the tlb flush flow. and several clean up
patches about the tlb_flush.

change note:
v3:
   1. Use the gather to implement the tlb_flush suggested from Tomasz.
   2. add some clean up patches.

v2:
https://lore.kernel.org/linux-iommu/1570627143-29441-1-git-send-email-yong.wu@mediatek.com/T/#t
   1. rebase on v5.4-rc1
   2. only split to several patches.

v1:
https://lore.kernel.org/linux-iommu/CAAFQd5C3U7pZo4SSUJ52Q7E+0FaUoORQFbQC5RhCHBhi=NFYTw@mail.gmail.com/T/#t

Yong Wu (7):
  iommu/mediatek: Correct the flush_iotlb_all callback
  iommu/mediatek: Add pgtlock in the iotlb_sync
  iommu/mediatek: Use gather to achieve the tlb range flush
  iommu/mediatek: Delete the leaf in the tlb flush
  iommu/mediatek: Move the tlb_sync into tlb_flush
  iommu/mediatek: Use writel for TLB range invalidation
  iommu/mediatek: Reduce the tlb flush timeout value

 drivers/iommu/mtk_iommu.c | 77 +++++++++++++++++++++++------------------------
 drivers/iommu/mtk_iommu.h |  2 +-
 2 files changed, 38 insertions(+), 41 deletions(-)

-- 
1.9.1

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[PATCH v3 1/7] iommu/mediatek: Correct the flush_iotlb_all callback

[Yong Wu]

Use the correct tlb_flush_all instead of the original one.

Fixes: 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API TLB sync")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 67a483c..76b9388 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -447,7 +447,7 @@ static size_t mtk_iommu_unmap(struct iommu_domain *domain,
 
 static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
 {
-	mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data());
+	mtk_iommu_tlb_flush_all(mtk_iommu_get_m4u_data());
 }
 
 static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
-- 
1.9.1

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Re: [PATCH v3 1/7] iommu/mediatek: Correct the flush_iotlb_all callback

[Robin Murphy]

On 14/10/2019 07:38, Yong Wu wrote:
> Use the correct tlb_flush_all instead of the original one.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> Fixes: 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API TLB sync")
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
>   drivers/iommu/mtk_iommu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 67a483c..76b9388 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -447,7 +447,7 @@ static size_t mtk_iommu_unmap(struct iommu_domain *domain,
>   
>   static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
>   {
> -	mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data());
> +	mtk_iommu_tlb_flush_all(mtk_iommu_get_m4u_data());
>   }
>   
>   static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
> 
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[PATCH v3 2/7] iommu/mediatek: Add pgtlock in the iotlb_sync

[Yong Wu]

The commit 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API
TLB sync") help move the tlb_sync of unmap from v7s into the iommu
framework. It helps add a new function "mtk_iommu_iotlb_sync", But it
lacked the dom->pgtlock, then it will cause the variable "tlb_flush_active"
may be changed unexpectedly, we could see this warning log randomly:

mtk-iommu 10205000.iommu: Partial TLB flush timed out, falling back to
full flush

This patch adds dom->pgtlock in mtk_iommu_iotlb_sync to fix this issue.

Fixes: 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API TLB sync")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 76b9388..5f594d6 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -453,7 +453,12 @@ static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
 static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
 				 struct iommu_iotlb_gather *gather)
 {
+	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dom->pgtlock, flags);
 	mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data());
+	spin_unlock_irqrestore(&dom->pgtlock, flags);
 }
 
 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
-- 
1.9.1

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[PATCH v3 3/7] iommu/mediatek: Use gather to achieve the tlb range flush

[Yong Wu]

Use the iommu_gather mechanism to achieve the tlb range flush.
Gather the iova range in the "tlb_add_page", then flush the merged iova
range in iotlb_sync.

Note: If iotlb_sync comes from iommu_iotlb_gather_add_page, we have to
avoid retry the lock since the spinlock have already been acquired.

Suggested-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
1) This is the special case backtrace:

 mtk_iommu_iotlb_sync+0x50/0xa0
 mtk_iommu_tlb_flush_page_nosync+0x5c/0xd0
 __arm_v7s_unmap+0x174/0x598
 arm_v7s_unmap+0x30/0x48
 mtk_iommu_unmap+0x50/0x78
 __iommu_unmap+0xa4/0xf8

2) The checking "if (gather->start == ULONG_MAX) return;" also is
necessary. It will happened when unmap only go to _flush_walk, then
enter this tlb_sync.
---
 drivers/iommu/mtk_iommu.c | 29 +++++++++++++++++++++++++----
 drivers/iommu/mtk_iommu.h |  1 +
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 5f594d6..8712afc 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -234,7 +234,12 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
 					    unsigned long iova, size_t granule,
 					    void *cookie)
 {
-	mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie);
+	struct mtk_iommu_data *data = cookie;
+	struct iommu_domain *domain = &data->m4u_dom->domain;
+
+	data->is_in_tlb_gather_add_page = true;
+	iommu_iotlb_gather_add_page(domain, gather, iova, granule);
+	data->is_in_tlb_gather_add_page = false;
 }
 
 static const struct iommu_flush_ops mtk_iommu_flush_ops = {
@@ -453,12 +458,28 @@ static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
 static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
 				 struct iommu_iotlb_gather *gather)
 {
+	struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
+	bool is_in_gather = data->is_in_tlb_gather_add_page;
+	size_t length = gather->end - gather->start;
 	unsigned long flags;
 
-	spin_lock_irqsave(&dom->pgtlock, flags);
-	mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data());
-	spin_unlock_irqrestore(&dom->pgtlock, flags);
+	if (gather->start == ULONG_MAX)
+		return;
+
+	/*
+	 * Avoid acquire the lock when it's in gather_add_page since the lock
+	 * has already been held.
+	 */
+	if (!is_in_gather)
+		spin_lock_irqsave(&dom->pgtlock, flags);
+
+	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
+				       false, data);
+	mtk_iommu_tlb_sync(data);
+
+	if (!is_in_gather)
+		spin_unlock_irqrestore(&dom->pgtlock, flags);
 }
 
 static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index fc0f16e..d29af1d 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -58,6 +58,7 @@ struct mtk_iommu_data {
 	struct iommu_group		*m4u_group;
 	bool                            enable_4GB;
 	bool				tlb_flush_active;
+	bool				is_in_tlb_gather_add_page;
 
 	struct iommu_device		iommu;
 	const struct mtk_iommu_plat_data *plat_data;
-- 
1.9.1

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Re: [PATCH v3 3/7] iommu/mediatek: Use gather to achieve the tlb range flush

[Robin Murphy]

On 14/10/2019 07:38, Yong Wu wrote:
> Use the iommu_gather mechanism to achieve the tlb range flush.
> Gather the iova range in the "tlb_add_page", then flush the merged iova
> range in iotlb_sync.
> 
> Note: If iotlb_sync comes from iommu_iotlb_gather_add_page, we have to
> avoid retry the lock since the spinlock have already been acquired.

I think this could probably be even simpler - once the actual 
register-poking is all confined to mtk_iommu_tlb_sync(), you should be 
able get rid of the per-domain locking in map/unmap and just have a 
single per-IOMMU lock to serialise syncs. The io-pgtable code itself 
hasn't needed external locking for a while now.

Robin.

> Suggested-by: Tomasz Figa <tfiga@chromium.org>
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
> 1) This is the special case backtrace:
> 
>   mtk_iommu_iotlb_sync+0x50/0xa0
>   mtk_iommu_tlb_flush_page_nosync+0x5c/0xd0
>   __arm_v7s_unmap+0x174/0x598
>   arm_v7s_unmap+0x30/0x48
>   mtk_iommu_unmap+0x50/0x78
>   __iommu_unmap+0xa4/0xf8
> 
> 2) The checking "if (gather->start == ULONG_MAX) return;" also is
> necessary. It will happened when unmap only go to _flush_walk, then
> enter this tlb_sync.
> ---
>   drivers/iommu/mtk_iommu.c | 29 +++++++++++++++++++++++++----
>   drivers/iommu/mtk_iommu.h |  1 +
>   2 files changed, 26 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 5f594d6..8712afc 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -234,7 +234,12 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
>   					    unsigned long iova, size_t granule,
>   					    void *cookie)
>   {
> -	mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie);
> +	struct mtk_iommu_data *data = cookie;
> +	struct iommu_domain *domain = &data->m4u_dom->domain;
> +
> +	data->is_in_tlb_gather_add_page = true;
> +	iommu_iotlb_gather_add_page(domain, gather, iova, granule);
> +	data->is_in_tlb_gather_add_page = false;
>   }
>   
>   static const struct iommu_flush_ops mtk_iommu_flush_ops = {
> @@ -453,12 +458,28 @@ static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
>   static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
>   				 struct iommu_iotlb_gather *gather)
>   {
> +	struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
>   	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> +	bool is_in_gather = data->is_in_tlb_gather_add_page;
> +	size_t length = gather->end - gather->start;
>   	unsigned long flags;
>   
> -	spin_lock_irqsave(&dom->pgtlock, flags);
> -	mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data());
> -	spin_unlock_irqrestore(&dom->pgtlock, flags);
> +	if (gather->start == ULONG_MAX)
> +		return;
> +
> +	/*
> +	 * Avoid acquire the lock when it's in gather_add_page since the lock
> +	 * has already been held.
> +	 */
> +	if (!is_in_gather)
> +		spin_lock_irqsave(&dom->pgtlock, flags);
> +
> +	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
> +				       false, data);
> +	mtk_iommu_tlb_sync(data);
> +
> +	if (!is_in_gather)
> +		spin_unlock_irqrestore(&dom->pgtlock, flags);
>   }
>   
>   static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
> diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
> index fc0f16e..d29af1d 100644
> --- a/drivers/iommu/mtk_iommu.h
> +++ b/drivers/iommu/mtk_iommu.h
> @@ -58,6 +58,7 @@ struct mtk_iommu_data {
>   	struct iommu_group		*m4u_group;
>   	bool                            enable_4GB;
>   	bool				tlb_flush_active;
> +	bool				is_in_tlb_gather_add_page;
>   
>   	struct iommu_device		iommu;
>   	const struct mtk_iommu_plat_data *plat_data;
> 
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Re: [PATCH v3 3/7] iommu/mediatek: Use gather to achieve the tlb range flush

[Yong Wu]

On Mon, 2019-10-14 at 15:21 +0100, Robin Murphy wrote:
> On 14/10/2019 07:38, Yong Wu wrote:
> > Use the iommu_gather mechanism to achieve the tlb range flush.
> > Gather the iova range in the "tlb_add_page", then flush the merged iova
> > range in iotlb_sync.
> > 
> > Note: If iotlb_sync comes from iommu_iotlb_gather_add_page, we have to
> > avoid retry the lock since the spinlock have already been acquired.
> 
> I think this could probably be even simpler - once the actual 
> register-poking is all confined to mtk_iommu_tlb_sync(), you should be 
> able get rid of the per-domain locking in map/unmap and just have a 
> single per-IOMMU lock to serialise syncs. The io-pgtable code itself 
> hasn't needed external locking for a while now.

This is more simpler! Thanks very much. I will try this.

The only concern is there is no lock in the iova_to_phys then, maybe use
the new lock instead.

> 
> Robin.
> 
> > Suggested-by: Tomasz Figa <tfiga@chromium.org>
> > Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> > ---
> > 1) This is the special case backtrace:
> > 
> >   mtk_iommu_iotlb_sync+0x50/0xa0
> >   mtk_iommu_tlb_flush_page_nosync+0x5c/0xd0
> >   __arm_v7s_unmap+0x174/0x598
> >   arm_v7s_unmap+0x30/0x48
> >   mtk_iommu_unmap+0x50/0x78
> >   __iommu_unmap+0xa4/0xf8
> > 
> > 2) The checking "if (gather->start == ULONG_MAX) return;" also is
> > necessary. It will happened when unmap only go to _flush_walk, then
> > enter this tlb_sync.
> > ---
> >   drivers/iommu/mtk_iommu.c | 29 +++++++++++++++++++++++++----
> >   drivers/iommu/mtk_iommu.h |  1 +
> >   2 files changed, 26 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index 5f594d6..8712afc 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -234,7 +234,12 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
> >   					    unsigned long iova, size_t granule,
> >   					    void *cookie)
> >   {
> > -	mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie);
> > +	struct mtk_iommu_data *data = cookie;
> > +	struct iommu_domain *domain = &data->m4u_dom->domain;
> > +
> > +	data->is_in_tlb_gather_add_page = true;
> > +	iommu_iotlb_gather_add_page(domain, gather, iova, granule);
> > +	data->is_in_tlb_gather_add_page = false;
> >   }
> >   
> >   static const struct iommu_flush_ops mtk_iommu_flush_ops = {
> > @@ -453,12 +458,28 @@ static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
> >   static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
> >   				 struct iommu_iotlb_gather *gather)
> >   {
> > +	struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
> >   	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> > +	bool is_in_gather = data->is_in_tlb_gather_add_page;
> > +	size_t length = gather->end - gather->start;
> >   	unsigned long flags;
> >   
> > -	spin_lock_irqsave(&dom->pgtlock, flags);
> > -	mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data());
> > -	spin_unlock_irqrestore(&dom->pgtlock, flags);
> > +	if (gather->start == ULONG_MAX)
> > +		return;
> > +
> > +	/*
> > +	 * Avoid acquire the lock when it's in gather_add_page since the lock
> > +	 * has already been held.
> > +	 */
> > +	if (!is_in_gather)
> > +		spin_lock_irqsave(&dom->pgtlock, flags);
> > +
> > +	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
> > +				       false, data);
> > +	mtk_iommu_tlb_sync(data);
> > +
> > +	if (!is_in_gather)
> > +		spin_unlock_irqrestore(&dom->pgtlock, flags);
> >   }
> >   
> >   static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
> > diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
> > index fc0f16e..d29af1d 100644
> > --- a/drivers/iommu/mtk_iommu.h
> > +++ b/drivers/iommu/mtk_iommu.h
> > @@ -58,6 +58,7 @@ struct mtk_iommu_data {
> >   	struct iommu_group		*m4u_group;
> >   	bool                            enable_4GB;
> >   	bool				tlb_flush_active;
> > +	bool				is_in_tlb_gather_add_page;
> >   
> >   	struct iommu_device		iommu;
> >   	const struct mtk_iommu_plat_data *plat_data;
> > 


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Re: [PATCH v3 3/7] iommu/mediatek: Use gather to achieve the tlb range flush

[Robin Murphy]

On 15/10/2019 06:26, Yong Wu wrote:
> On Mon, 2019-10-14 at 15:21 +0100, Robin Murphy wrote:
>> On 14/10/2019 07:38, Yong Wu wrote:
>>> Use the iommu_gather mechanism to achieve the tlb range flush.
>>> Gather the iova range in the "tlb_add_page", then flush the merged iova
>>> range in iotlb_sync.
>>>
>>> Note: If iotlb_sync comes from iommu_iotlb_gather_add_page, we have to
>>> avoid retry the lock since the spinlock have already been acquired.
>>
>> I think this could probably be even simpler - once the actual
>> register-poking is all confined to mtk_iommu_tlb_sync(), you should be
>> able get rid of the per-domain locking in map/unmap and just have a
>> single per-IOMMU lock to serialise syncs. The io-pgtable code itself
>> hasn't needed external locking for a while now.
> 
> This is more simpler! Thanks very much. I will try this.
> 
> The only concern is there is no lock in the iova_to_phys then, maybe use
> the new lock instead.

iova_to_phys isn't issuing any syncs, so you don't need any locking 
there - if anyone calls that in a way which races against the given 
address being unmapped and remapped they can't expect a meaningful 
result anyway.

Robin.

>>> Suggested-by: Tomasz Figa <tfiga@chromium.org>
>>> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
>>> ---
>>> 1) This is the special case backtrace:
>>>
>>>    mtk_iommu_iotlb_sync+0x50/0xa0
>>>    mtk_iommu_tlb_flush_page_nosync+0x5c/0xd0
>>>    __arm_v7s_unmap+0x174/0x598
>>>    arm_v7s_unmap+0x30/0x48
>>>    mtk_iommu_unmap+0x50/0x78
>>>    __iommu_unmap+0xa4/0xf8
>>>
>>> 2) The checking "if (gather->start == ULONG_MAX) return;" also is
>>> necessary. It will happened when unmap only go to _flush_walk, then
>>> enter this tlb_sync.
>>> ---
>>>    drivers/iommu/mtk_iommu.c | 29 +++++++++++++++++++++++++----
>>>    drivers/iommu/mtk_iommu.h |  1 +
>>>    2 files changed, 26 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
>>> index 5f594d6..8712afc 100644
>>> --- a/drivers/iommu/mtk_iommu.c
>>> +++ b/drivers/iommu/mtk_iommu.c
>>> @@ -234,7 +234,12 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
>>>    					    unsigned long iova, size_t granule,
>>>    					    void *cookie)
>>>    {
>>> -	mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie);
>>> +	struct mtk_iommu_data *data = cookie;
>>> +	struct iommu_domain *domain = &data->m4u_dom->domain;
>>> +
>>> +	data->is_in_tlb_gather_add_page = true;
>>> +	iommu_iotlb_gather_add_page(domain, gather, iova, granule);
>>> +	data->is_in_tlb_gather_add_page = false;
>>>    }
>>>    
>>>    static const struct iommu_flush_ops mtk_iommu_flush_ops = {
>>> @@ -453,12 +458,28 @@ static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain)
>>>    static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
>>>    				 struct iommu_iotlb_gather *gather)
>>>    {
>>> +	struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
>>>    	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
>>> +	bool is_in_gather = data->is_in_tlb_gather_add_page;
>>> +	size_t length = gather->end - gather->start;
>>>    	unsigned long flags;
>>>    
>>> -	spin_lock_irqsave(&dom->pgtlock, flags);
>>> -	mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data());
>>> -	spin_unlock_irqrestore(&dom->pgtlock, flags);
>>> +	if (gather->start == ULONG_MAX)
>>> +		return;
>>> +
>>> +	/*
>>> +	 * Avoid acquire the lock when it's in gather_add_page since the lock
>>> +	 * has already been held.
>>> +	 */
>>> +	if (!is_in_gather)
>>> +		spin_lock_irqsave(&dom->pgtlock, flags);
>>> +
>>> +	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
>>> +				       false, data);
>>> +	mtk_iommu_tlb_sync(data);
>>> +
>>> +	if (!is_in_gather)
>>> +		spin_unlock_irqrestore(&dom->pgtlock, flags);
>>>    }
>>>    
>>>    static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
>>> diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
>>> index fc0f16e..d29af1d 100644
>>> --- a/drivers/iommu/mtk_iommu.h
>>> +++ b/drivers/iommu/mtk_iommu.h
>>> @@ -58,6 +58,7 @@ struct mtk_iommu_data {
>>>    	struct iommu_group		*m4u_group;
>>>    	bool                            enable_4GB;
>>>    	bool				tlb_flush_active;
>>> +	bool				is_in_tlb_gather_add_page;
>>>    
>>>    	struct iommu_device		iommu;
>>>    	const struct mtk_iommu_plat_data *plat_data;
>>>
> 
> 
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[PATCH v3 4/7] iommu/mediatek: Delete the leaf in the tlb flush

[Yong Wu]

In our tlb range flush, we don't care the "leaf". Remove it to simplify
the code. no functional change.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 8712afc..19f936c 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -174,8 +174,7 @@ static void mtk_iommu_tlb_flush_all(void *cookie)
 }
 
 static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
-					   size_t granule, bool leaf,
-					   void *cookie)
+					   size_t granule, void *cookie)
 {
 	struct mtk_iommu_data *data = cookie;
 
@@ -219,14 +218,7 @@ static void mtk_iommu_tlb_sync(void *cookie)
 static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size,
 				     size_t granule, void *cookie)
 {
-	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, false, cookie);
-	mtk_iommu_tlb_sync(cookie);
-}
-
-static void mtk_iommu_tlb_flush_leaf(unsigned long iova, size_t size,
-				     size_t granule, void *cookie)
-{
-	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, true, cookie);
+	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, cookie);
 	mtk_iommu_tlb_sync(cookie);
 }
 
@@ -245,7 +237,7 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
 static const struct iommu_flush_ops mtk_iommu_flush_ops = {
 	.tlb_flush_all = mtk_iommu_tlb_flush_all,
 	.tlb_flush_walk = mtk_iommu_tlb_flush_walk,
-	.tlb_flush_leaf = mtk_iommu_tlb_flush_leaf,
+	.tlb_flush_leaf = mtk_iommu_tlb_flush_walk,
 	.tlb_add_page = mtk_iommu_tlb_flush_page_nosync,
 };
 
@@ -475,7 +467,7 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
 		spin_lock_irqsave(&dom->pgtlock, flags);
 
 	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
-				       false, data);
+				       data);
 	mtk_iommu_tlb_sync(data);
 
 	if (!is_in_gather)
-- 
1.9.1

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Re: [PATCH v3 4/7] iommu/mediatek: Delete the leaf in the tlb flush

[Robin Murphy]

On 14/10/2019 07:38, Yong Wu wrote:
> In our tlb range flush, we don't care the "leaf". Remove it to simplify
> the code. no functional change.

Presumably you don't care about the granule either?

Robin.

> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
>   drivers/iommu/mtk_iommu.c | 16 ++++------------
>   1 file changed, 4 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index 8712afc..19f936c 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -174,8 +174,7 @@ static void mtk_iommu_tlb_flush_all(void *cookie)
>   }
>   
>   static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
> -					   size_t granule, bool leaf,
> -					   void *cookie)
> +					   size_t granule, void *cookie)
>   {
>   	struct mtk_iommu_data *data = cookie;
>   
> @@ -219,14 +218,7 @@ static void mtk_iommu_tlb_sync(void *cookie)
>   static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size,
>   				     size_t granule, void *cookie)
>   {
> -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, false, cookie);
> -	mtk_iommu_tlb_sync(cookie);
> -}
> -
> -static void mtk_iommu_tlb_flush_leaf(unsigned long iova, size_t size,
> -				     size_t granule, void *cookie)
> -{
> -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, true, cookie);
> +	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, cookie);
>   	mtk_iommu_tlb_sync(cookie);
>   }
>   
> @@ -245,7 +237,7 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
>   static const struct iommu_flush_ops mtk_iommu_flush_ops = {
>   	.tlb_flush_all = mtk_iommu_tlb_flush_all,
>   	.tlb_flush_walk = mtk_iommu_tlb_flush_walk,
> -	.tlb_flush_leaf = mtk_iommu_tlb_flush_leaf,
> +	.tlb_flush_leaf = mtk_iommu_tlb_flush_walk,
>   	.tlb_add_page = mtk_iommu_tlb_flush_page_nosync,
>   };
>   
> @@ -475,7 +467,7 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
>   		spin_lock_irqsave(&dom->pgtlock, flags);
>   
>   	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
> -				       false, data);
> +				       data);
>   	mtk_iommu_tlb_sync(data);
>   
>   	if (!is_in_gather)
> 
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Re: [PATCH v3 4/7] iommu/mediatek: Delete the leaf in the tlb flush

[Yong Wu]

On Mon, 2019-10-14 at 15:22 +0100, Robin Murphy wrote:
> On 14/10/2019 07:38, Yong Wu wrote:
> > In our tlb range flush, we don't care the "leaf". Remove it to simplify
> > the code. no functional change.
> 
> Presumably you don't care about the granule either?

Yes. I only keep "granule" to satisfy the format of "tlb_flush_walk",
then it's no need add a new helper function.

> 
> Robin.
> 
> > Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> > ---
> >   drivers/iommu/mtk_iommu.c | 16 ++++------------
> >   1 file changed, 4 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index 8712afc..19f936c 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -174,8 +174,7 @@ static void mtk_iommu_tlb_flush_all(void *cookie)
> >   }
> >   
> >   static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
> > -					   size_t granule, bool leaf,
> > -					   void *cookie)
> > +					   size_t granule, void *cookie)
> >   {
> >   	struct mtk_iommu_data *data = cookie;
> >   
> > @@ -219,14 +218,7 @@ static void mtk_iommu_tlb_sync(void *cookie)
> >   static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size,
> >   				     size_t granule, void *cookie)
> >   {
> > -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, false, cookie);
> > -	mtk_iommu_tlb_sync(cookie);
> > -}
> > -
> > -static void mtk_iommu_tlb_flush_leaf(unsigned long iova, size_t size,
> > -				     size_t granule, void *cookie)
> > -{
> > -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, true, cookie);
> > +	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, cookie);
> >   	mtk_iommu_tlb_sync(cookie);
> >   }
> >   
> > @@ -245,7 +237,7 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
> >   static const struct iommu_flush_ops mtk_iommu_flush_ops = {
> >   	.tlb_flush_all = mtk_iommu_tlb_flush_all,
> >   	.tlb_flush_walk = mtk_iommu_tlb_flush_walk,
> > -	.tlb_flush_leaf = mtk_iommu_tlb_flush_leaf,
> > +	.tlb_flush_leaf = mtk_iommu_tlb_flush_walk,
> >   	.tlb_add_page = mtk_iommu_tlb_flush_page_nosync,
> >   };
> >   
> > @@ -475,7 +467,7 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
> >   		spin_lock_irqsave(&dom->pgtlock, flags);
> >   
> >   	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
> > -				       false, data);
> > +				       data);
> >   	mtk_iommu_tlb_sync(data);
> >   
> >   	if (!is_in_gather)
> > 
> 
> _______________________________________________
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> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek


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Re: [PATCH v3 4/7] iommu/mediatek: Delete the leaf in the tlb flush

[Robin Murphy]

On 15/10/2019 06:25, Yong Wu wrote:
> On Mon, 2019-10-14 at 15:22 +0100, Robin Murphy wrote:
>> On 14/10/2019 07:38, Yong Wu wrote:
>>> In our tlb range flush, we don't care the "leaf". Remove it to simplify
>>> the code. no functional change.
>>
>> Presumably you don't care about the granule either?
> 
> Yes. I only keep "granule" to satisfy the format of "tlb_flush_walk",
> then it's no need add a new helper function.

Ah, I'd failed to make the connection that it ends up wired in directly 
to the callbacks in patch #5 - indeed there's no point churning the 
mtk_iommu_tlb_add_flush_nosync() callsites here if they're just getting 
removed later anyway. In that case,

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

>>> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
>>> ---
>>>    drivers/iommu/mtk_iommu.c | 16 ++++------------
>>>    1 file changed, 4 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
>>> index 8712afc..19f936c 100644
>>> --- a/drivers/iommu/mtk_iommu.c
>>> +++ b/drivers/iommu/mtk_iommu.c
>>> @@ -174,8 +174,7 @@ static void mtk_iommu_tlb_flush_all(void *cookie)
>>>    }
>>>    
>>>    static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
>>> -					   size_t granule, bool leaf,
>>> -					   void *cookie)
>>> +					   size_t granule, void *cookie)
>>>    {
>>>    	struct mtk_iommu_data *data = cookie;
>>>    
>>> @@ -219,14 +218,7 @@ static void mtk_iommu_tlb_sync(void *cookie)
>>>    static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size,
>>>    				     size_t granule, void *cookie)
>>>    {
>>> -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, false, cookie);
>>> -	mtk_iommu_tlb_sync(cookie);
>>> -}
>>> -
>>> -static void mtk_iommu_tlb_flush_leaf(unsigned long iova, size_t size,
>>> -				     size_t granule, void *cookie)
>>> -{
>>> -	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, true, cookie);
>>> +	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, cookie);
>>>    	mtk_iommu_tlb_sync(cookie);
>>>    }
>>>    
>>> @@ -245,7 +237,7 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
>>>    static const struct iommu_flush_ops mtk_iommu_flush_ops = {
>>>    	.tlb_flush_all = mtk_iommu_tlb_flush_all,
>>>    	.tlb_flush_walk = mtk_iommu_tlb_flush_walk,
>>> -	.tlb_flush_leaf = mtk_iommu_tlb_flush_leaf,
>>> +	.tlb_flush_leaf = mtk_iommu_tlb_flush_walk,
>>>    	.tlb_add_page = mtk_iommu_tlb_flush_page_nosync,
>>>    };
>>>    
>>> @@ -475,7 +467,7 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
>>>    		spin_lock_irqsave(&dom->pgtlock, flags);
>>>    
>>>    	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
>>> -				       false, data);
>>> +				       data);
>>>    	mtk_iommu_tlb_sync(data);
>>>    
>>>    	if (!is_in_gather)
>>>
>>
>> _______________________________________________
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>> http://lists.infradead.org/mailman/listinfo/linux-mediatek
> 
> 
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[PATCH v3 5/7] iommu/mediatek: Move the tlb_sync into tlb_flush

[Yong Wu]

Right now, the tlb_add_flush_nosync and tlb_sync always appear together.
we merge the two functions into one. No functional change.

mtk_iommu_tlb_add_flush_nosync
mtk_iommu_tlb_sync

Signed-off-by: Chao Hao <chao.hao@mediatek.com>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 36 ++++++++----------------------------
 drivers/iommu/mtk_iommu.h |  1 -
 2 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 19f936c..dbbacc3 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -173,10 +173,12 @@ static void mtk_iommu_tlb_flush_all(void *cookie)
 	}
 }
 
-static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
+static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
 					   size_t granule, void *cookie)
 {
 	struct mtk_iommu_data *data = cookie;
+	int ret;
+	u32 tmp;
 
 	for_each_m4u(data) {
 		writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0,
@@ -187,21 +189,8 @@ static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size,
 			       data->base + REG_MMU_INVLD_END_A);
 		writel_relaxed(F_MMU_INV_RANGE,
 			       data->base + REG_MMU_INVALIDATE);
-		data->tlb_flush_active = true;
-	}
-}
-
-static void mtk_iommu_tlb_sync(void *cookie)
-{
-	struct mtk_iommu_data *data = cookie;
-	int ret;
-	u32 tmp;
-
-	for_each_m4u(data) {
-		/* Avoid timing out if there's nothing to wait for */
-		if (!data->tlb_flush_active)
-			return;
 
+		/* tlb sync */
 		ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
 						tmp, tmp != 0, 10, 100000);
 		if (ret) {
@@ -211,17 +200,9 @@ static void mtk_iommu_tlb_sync(void *cookie)
 		}
 		/* Clear the CPE status */
 		writel_relaxed(0, data->base + REG_MMU_CPE_DONE);
-		data->tlb_flush_active = false;
 	}
 }
 
-static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size,
-				     size_t granule, void *cookie)
-{
-	mtk_iommu_tlb_add_flush_nosync(iova, size, granule, cookie);
-	mtk_iommu_tlb_sync(cookie);
-}
-
 static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
 					    unsigned long iova, size_t granule,
 					    void *cookie)
@@ -236,8 +217,8 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather,
 
 static const struct iommu_flush_ops mtk_iommu_flush_ops = {
 	.tlb_flush_all = mtk_iommu_tlb_flush_all,
-	.tlb_flush_walk = mtk_iommu_tlb_flush_walk,
-	.tlb_flush_leaf = mtk_iommu_tlb_flush_walk,
+	.tlb_flush_walk = mtk_iommu_tlb_flush_range_sync,
+	.tlb_flush_leaf = mtk_iommu_tlb_flush_range_sync,
 	.tlb_add_page = mtk_iommu_tlb_flush_page_nosync,
 };
 
@@ -466,9 +447,8 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain,
 	if (!is_in_gather)
 		spin_lock_irqsave(&dom->pgtlock, flags);
 
-	mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize,
-				       data);
-	mtk_iommu_tlb_sync(data);
+	mtk_iommu_tlb_flush_range_sync(gather->start, length,
+				       gather->pgsize, data);
 
 	if (!is_in_gather)
 		spin_unlock_irqrestore(&dom->pgtlock, flags);
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index d29af1d..9056f73 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -57,7 +57,6 @@ struct mtk_iommu_data {
 	struct mtk_iommu_domain		*m4u_dom;
 	struct iommu_group		*m4u_group;
 	bool                            enable_4GB;
-	bool				tlb_flush_active;
 	bool				is_in_tlb_gather_add_page;
 
 	struct iommu_device		iommu;
-- 
1.9.1

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[PATCH v3 6/7] iommu/mediatek: Use writel for TLB range invalidation

[Yong Wu]

Use writel for the register F_MMU_INV_RANGE which is for triggering the
HW work. We expect all the setting(iova_start/iova_end...) have already
been finished before F_MMU_INV_RANGE.

Signed-off-by: Anan.Sun <anan.sun@mediatek.com>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index dbbacc3..d285457 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -187,8 +187,7 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
 		writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
 		writel_relaxed(iova + size - 1,
 			       data->base + REG_MMU_INVLD_END_A);
-		writel_relaxed(F_MMU_INV_RANGE,
-			       data->base + REG_MMU_INVALIDATE);
+		writel(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
 
 		/* tlb sync */
 		ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
-- 
1.9.1

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Re: [PATCH v3 6/7] iommu/mediatek: Use writel for TLB range invalidation

[Robin Murphy]

On 14/10/2019 07:38, Yong Wu wrote:
> Use writel for the register F_MMU_INV_RANGE which is for triggering the
> HW work. We expect all the setting(iova_start/iova_end...) have already
> been finished before F_MMU_INV_RANGE.

For Arm CPUs, these registers should be mapped as Device memory, 
therefore the same-peripheral rule should implicitly enforce that the 
accesses are made in program order, hence you're unlikely to have seen a 
problem in reality. However, the logical reasoning for the change seems 
valid in general, so I'd argue that it's still worth making if only for 
the sake of good practice:

Acked-by: Robin Murphy <robin.murphy@arm.com>

> Signed-off-by: Anan.Sun <anan.sun@mediatek.com>
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
>   drivers/iommu/mtk_iommu.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index dbbacc3..d285457 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -187,8 +187,7 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
>   		writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
>   		writel_relaxed(iova + size - 1,
>   			       data->base + REG_MMU_INVLD_END_A);
> -		writel_relaxed(F_MMU_INV_RANGE,
> -			       data->base + REG_MMU_INVALIDATE);
> +		writel(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
>   
>   		/* tlb sync */
>   		ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
> 
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Re: [PATCH v3 6/7] iommu/mediatek: Use writel for TLB range invalidation

[Yong Wu]

On Mon, 2019-10-14 at 15:04 +0100, Robin Murphy wrote:
> On 14/10/2019 07:38, Yong Wu wrote:
> > Use writel for the register F_MMU_INV_RANGE which is for triggering the
> > HW work. We expect all the setting(iova_start/iova_end...) have already
> > been finished before F_MMU_INV_RANGE.
> 
> For Arm CPUs, these registers should be mapped as Device memory, 
> therefore the same-peripheral rule should implicitly enforce that the 
> accesses are made in program order, hence you're unlikely to have seen a 
> problem in reality. However, the logical reasoning for the change seems 
> valid in general, so I'd argue that it's still worth making if only for 
> the sake of good practice:
> 
> Acked-by: Robin Murphy <robin.murphy@arm.com>

Thanks very much for the view. If this patch is not so necessary, I will
remove it this time.

> 
> > Signed-off-by: Anan.Sun <anan.sun@mediatek.com>
> > Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> > ---
> >   drivers/iommu/mtk_iommu.c | 3 +--
> >   1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index dbbacc3..d285457 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -187,8 +187,7 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
> >   		writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
> >   		writel_relaxed(iova + size - 1,
> >   			       data->base + REG_MMU_INVLD_END_A);
> > -		writel_relaxed(F_MMU_INV_RANGE,
> > -			       data->base + REG_MMU_INVALIDATE);
> > +		writel(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
> >   
> >   		/* tlb sync */
> >   		ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
> > 
> 
> _______________________________________________
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> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek


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[PATCH v3 7/7] iommu/mediatek: Reduce the tlb flush timeout value

[Yong Wu]

Reduce the tlb timeout value from 100000us to 1000us. the original value
is so long that affect the multimedia performance. This is only a minor
improvement rather than fixing a issue.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index d285457..c9d49af 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -191,7 +191,7 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
 
 		/* tlb sync */
 		ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
-						tmp, tmp != 0, 10, 100000);
+						tmp, tmp != 0, 10, 1000);
 		if (ret) {
 			dev_warn(data->dev,
 				 "Partial TLB flush timed out, falling back to full flush\n");
-- 
1.9.1

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