[RFC,v6,1/5] iommu: add an exported function to get minimum page size for a domain
diff mbox series

Message ID 1560421215-10750-2-git-send-email-yoshihiro.shimoda.uh@renesas.com
State New
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Series
  • treewide: improve R-Car SDHI performance
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Commit Message

Yoshihiro Shimoda June 13, 2019, 10:20 a.m. UTC
This patch adds an exported function to get minimum page size for
a domain. This patch also modifies similar codes on the iommu.c.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/iommu/iommu.c | 18 +++++++++++++++---
 include/linux/iommu.h |  1 +
 2 files changed, 16 insertions(+), 3 deletions(-)

Comments

Wolfram Sang June 13, 2019, 7:37 p.m. UTC | #1
On Thu, Jun 13, 2019 at 07:20:11PM +0900, Yoshihiro Shimoda wrote:
> This patch adds an exported function to get minimum page size for
> a domain. This patch also modifies similar codes on the iommu.c.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>  drivers/iommu/iommu.c | 18 +++++++++++++++---
>  include/linux/iommu.h |  1 +
>  2 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 2a90638..7ed16af 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -280,6 +280,18 @@ iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
>  	return ret;
>  }
>  
> +/**
> + * iommu_get_minimum_page_size - get minimum page size for a domain
> + * @domain: the domain
> + *
> + * Allow iommu driver to get a minimum page size for a domain.
> + */
> +unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain)
> +{
> +	return 1UL << __ffs(domain->pgsize_bitmap);
> +}
> +EXPORT_SYMBOL_GPL(iommu_get_minimum_page_size);

What about making this a 'static inline' in the iommu header file? I'd
think it is simple enough and would save us the EXPORT symbol.
Christoph Hellwig June 14, 2019, 7:16 a.m. UTC | #2
On Thu, Jun 13, 2019 at 09:37:59PM +0200, Wolfram Sang wrote:
> What about making this a 'static inline' in the iommu header file? I'd
> think it is simple enough and would save us the EXPORT symbol.

Agreed, this seems simple enought for an inline.
Robin Murphy June 14, 2019, 9:41 a.m. UTC | #3
On 13/06/2019 11:20, Yoshihiro Shimoda wrote:
> This patch adds an exported function to get minimum page size for
> a domain. This patch also modifies similar codes on the iommu.c.

Heh, seeing this gave me a genuine déjà vu moment...

...but it turns out I actually *have* reviewed this patch before :)

https://lore.kernel.org/lkml/05eca601-0264-8141-ceeb-7ef7ad5d5650@arm.com/

Robin.

> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>   drivers/iommu/iommu.c | 18 +++++++++++++++---
>   include/linux/iommu.h |  1 +
>   2 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 2a90638..7ed16af 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -280,6 +280,18 @@ iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
>   	return ret;
>   }
>   
> +/**
> + * iommu_get_minimum_page_size - get minimum page size for a domain
> + * @domain: the domain
> + *
> + * Allow iommu driver to get a minimum page size for a domain.
> + */
> +unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain)
> +{
> +	return 1UL << __ffs(domain->pgsize_bitmap);
> +}
> +EXPORT_SYMBOL_GPL(iommu_get_minimum_page_size);
> +
>   int iommu_get_group_resv_regions(struct iommu_group *group,
>   				 struct list_head *head)
>   {
> @@ -558,7 +570,7 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group,
>   
>   	BUG_ON(!domain->pgsize_bitmap);
>   
> -	pg_size = 1UL << __ffs(domain->pgsize_bitmap);
> +	pg_size = iommu_get_minimum_page_size(domain);
>   	INIT_LIST_HEAD(&mappings);
>   
>   	iommu_get_resv_regions(dev, &mappings);
> @@ -1595,7 +1607,7 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova,
>   		return -EINVAL;
>   
>   	/* find out the minimum page size supported */
> -	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
> +	min_pagesz = iommu_get_minimum_page_size(domain);
>   
>   	/*
>   	 * both the virtual address and the physical one, as well as
> @@ -1655,7 +1667,7 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
>   		return 0;
>   
>   	/* find out the minimum page size supported */
> -	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
> +	min_pagesz = iommu_get_minimum_page_size(domain);
>   
>   	/*
>   	 * The virtual address, as well as the size of the mapping, must be
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 91af22a..7e53b43 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -366,6 +366,7 @@ extern int iommu_request_dma_domain_for_dev(struct device *dev);
>   extern struct iommu_resv_region *
>   iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot,
>   			enum iommu_resv_type type);
> +extern unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain);
>   extern int iommu_get_group_resv_regions(struct iommu_group *group,
>   					struct list_head *head);
>   
>
Yoshihiro Shimoda June 17, 2019, 5:08 a.m. UTC | #4
Hi Wolfram-san,

> From: Wolfram Sang, Sent: Friday, June 14, 2019 4:38 AM
> 
> On Thu, Jun 13, 2019 at 07:20:11PM +0900, Yoshihiro Shimoda wrote:
> > This patch adds an exported function to get minimum page size for
> > a domain. This patch also modifies similar codes on the iommu.c.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > ---
> >  drivers/iommu/iommu.c | 18 +++++++++++++++---
> >  include/linux/iommu.h |  1 +
> >  2 files changed, 16 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> > index 2a90638..7ed16af 100644
> > --- a/drivers/iommu/iommu.c
> > +++ b/drivers/iommu/iommu.c
> > @@ -280,6 +280,18 @@ iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
> >  	return ret;
> >  }
> >
> > +/**
> > + * iommu_get_minimum_page_size - get minimum page size for a domain
> > + * @domain: the domain
> > + *
> > + * Allow iommu driver to get a minimum page size for a domain.
> > + */
> > +unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain)
> > +{
> > +	return 1UL << __ffs(domain->pgsize_bitmap);
> > +}
> > +EXPORT_SYMBOL_GPL(iommu_get_minimum_page_size);
> 
> What about making this a 'static inline' in the iommu header file? I'd
> think it is simple enough and would save us the EXPORT symbol.

Thank you for the review. I think so. I'll use 'static inline' instead of
EXPORT symbol.

Best regards,
Yoshihiro Shimoda
Yoshihiro Shimoda June 17, 2019, 5:23 a.m. UTC | #5
Hi Robin,

> From: Robin Murphy, Sent: Friday, June 14, 2019 6:41 PM
> 
> On 13/06/2019 11:20, Yoshihiro Shimoda wrote:
> > This patch adds an exported function to get minimum page size for
> > a domain. This patch also modifies similar codes on the iommu.c.
> 
> Heh, seeing this gave me a genuine déjà vu moment...
> 
> ...but it turns out I actually *have* reviewed this patch before :)
> 
> https://lore.kernel.org/lkml/05eca601-0264-8141-ceeb-7ef7ad5d5650@arm.com/

Thank you for the information :)
I realized my patch should have taken care of the CONFIG_IPMMU_API=n case.

However, the latest patch series doesn't have such a patch. So, I'll keep this
my patch on next patch version.
https://lore.kernel.org/lkml/20190603011620.31999-1-baolu.lu@linux.intel.com/

Best regards,
Yoshihiro Shimoda

> Robin.
> 
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > ---
> >   drivers/iommu/iommu.c | 18 +++++++++++++++---
> >   include/linux/iommu.h |  1 +
> >   2 files changed, 16 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> > index 2a90638..7ed16af 100644
> > --- a/drivers/iommu/iommu.c
> > +++ b/drivers/iommu/iommu.c
> > @@ -280,6 +280,18 @@ iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
> >   	return ret;
> >   }
> >
> > +/**
> > + * iommu_get_minimum_page_size - get minimum page size for a domain
> > + * @domain: the domain
> > + *
> > + * Allow iommu driver to get a minimum page size for a domain.
> > + */
> > +unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain)
> > +{
> > +	return 1UL << __ffs(domain->pgsize_bitmap);
> > +}
> > +EXPORT_SYMBOL_GPL(iommu_get_minimum_page_size);
> > +
> >   int iommu_get_group_resv_regions(struct iommu_group *group,
> >   				 struct list_head *head)
> >   {
> > @@ -558,7 +570,7 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group,
> >
> >   	BUG_ON(!domain->pgsize_bitmap);
> >
> > -	pg_size = 1UL << __ffs(domain->pgsize_bitmap);
> > +	pg_size = iommu_get_minimum_page_size(domain);
> >   	INIT_LIST_HEAD(&mappings);
> >
> >   	iommu_get_resv_regions(dev, &mappings);
> > @@ -1595,7 +1607,7 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova,
> >   		return -EINVAL;
> >
> >   	/* find out the minimum page size supported */
> > -	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
> > +	min_pagesz = iommu_get_minimum_page_size(domain);
> >
> >   	/*
> >   	 * both the virtual address and the physical one, as well as
> > @@ -1655,7 +1667,7 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
> >   		return 0;
> >
> >   	/* find out the minimum page size supported */
> > -	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
> > +	min_pagesz = iommu_get_minimum_page_size(domain);
> >
> >   	/*
> >   	 * The virtual address, as well as the size of the mapping, must be
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index 91af22a..7e53b43 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -366,6 +366,7 @@ extern int iommu_request_dma_domain_for_dev(struct device *dev);
> >   extern struct iommu_resv_region *
> >   iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot,
> >   			enum iommu_resv_type type);
> > +extern unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain);
> >   extern int iommu_get_group_resv_regions(struct iommu_group *group,
> >   					struct list_head *head);
> >
> >

Patch
diff mbox series

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 2a90638..7ed16af 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -280,6 +280,18 @@  iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
 	return ret;
 }
 
+/**
+ * iommu_get_minimum_page_size - get minimum page size for a domain
+ * @domain: the domain
+ *
+ * Allow iommu driver to get a minimum page size for a domain.
+ */
+unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain)
+{
+	return 1UL << __ffs(domain->pgsize_bitmap);
+}
+EXPORT_SYMBOL_GPL(iommu_get_minimum_page_size);
+
 int iommu_get_group_resv_regions(struct iommu_group *group,
 				 struct list_head *head)
 {
@@ -558,7 +570,7 @@  static int iommu_group_create_direct_mappings(struct iommu_group *group,
 
 	BUG_ON(!domain->pgsize_bitmap);
 
-	pg_size = 1UL << __ffs(domain->pgsize_bitmap);
+	pg_size = iommu_get_minimum_page_size(domain);
 	INIT_LIST_HEAD(&mappings);
 
 	iommu_get_resv_regions(dev, &mappings);
@@ -1595,7 +1607,7 @@  int iommu_map(struct iommu_domain *domain, unsigned long iova,
 		return -EINVAL;
 
 	/* find out the minimum page size supported */
-	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
+	min_pagesz = iommu_get_minimum_page_size(domain);
 
 	/*
 	 * both the virtual address and the physical one, as well as
@@ -1655,7 +1667,7 @@  static size_t __iommu_unmap(struct iommu_domain *domain,
 		return 0;
 
 	/* find out the minimum page size supported */
-	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
+	min_pagesz = iommu_get_minimum_page_size(domain);
 
 	/*
 	 * The virtual address, as well as the size of the mapping, must be
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 91af22a..7e53b43 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -366,6 +366,7 @@  extern int iommu_request_dma_domain_for_dev(struct device *dev);
 extern struct iommu_resv_region *
 iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot,
 			enum iommu_resv_type type);
+extern unsigned long iommu_get_minimum_page_size(struct iommu_domain *domain);
 extern int iommu_get_group_resv_regions(struct iommu_group *group,
 					struct list_head *head);