diff mbox series

[v9,2/5] iommu/dma: Add a new dma_map_ops of get_merge_boundary()

Message ID 1564129876-28261-3-git-send-email-yoshihiro.shimoda.uh@renesas.com (mailing list archive)
State New, archived
Headers show
Series treewide: improve R-Car SDHI performance | expand

Commit Message

Yoshihiro Shimoda July 26, 2019, 8:31 a.m. UTC 
This patch adds a new dma_map_ops of get_merge_boundary() to
expose the DMA merge boundary if the domain type is IOMMU_DOMAIN_DMA.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
---
 drivers/iommu/dma-iommu.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Wolfram Sang Aug. 16, 2019, 7:48 p.m. UTC | #1 
On Fri, Jul 26, 2019 at 05:31:13PM +0900, Yoshihiro Shimoda wrote:
> This patch adds a new dma_map_ops of get_merge_boundary() to
> expose the DMA merge boundary if the domain type is IOMMU_DOMAIN_DMA.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

Joerg, can we have your ack for this patch so Christoph can take this
series via his tree?

Thanks,

   Wolfram

> ---
>  drivers/iommu/dma-iommu.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index a7f9c3e..2992ce4 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -1085,6 +1085,16 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
>  	return ret;
>  }
>  
> +static unsigned long iommu_dma_get_merge_boundary(struct device *dev)
> +{
> +	struct iommu_domain *domain = iommu_get_dma_domain(dev);
> +
> +	if (domain->type != IOMMU_DOMAIN_DMA)
> +		return 0;	/* can't merge */
> +
> +	return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
> +}
> +
>  static const struct dma_map_ops iommu_dma_ops = {
>  	.alloc			= iommu_dma_alloc,
>  	.free			= iommu_dma_free,
> @@ -1100,6 +1110,7 @@ static const struct dma_map_ops iommu_dma_ops = {
>  	.sync_sg_for_device	= iommu_dma_sync_sg_for_device,
>  	.map_resource		= iommu_dma_map_resource,
>  	.unmap_resource		= iommu_dma_unmap_resource,
> +	.get_merge_boundary	= iommu_dma_get_merge_boundary,
>  };
>  
>  /*
> -- 
> 2.7.4
>
Joerg Roedel Aug. 19, 2019, 12:45 p.m. UTC | #2 
On Fri, Jul 26, 2019 at 05:31:13PM +0900, Yoshihiro Shimoda wrote:
> This patch adds a new dma_map_ops of get_merge_boundary() to
> expose the DMA merge boundary if the domain type is IOMMU_DOMAIN_DMA.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

Acked-by: Joerg Roedel <jroedel@suse.de>
Robin Murphy Aug. 19, 2019, 12:54 p.m. UTC | #3 
On 26/07/2019 09:31, Yoshihiro Shimoda wrote:
> This patch adds a new dma_map_ops of get_merge_boundary() to
> expose the DMA merge boundary if the domain type is IOMMU_DOMAIN_DMA.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
> ---
>   drivers/iommu/dma-iommu.c | 11 +++++++++++
>   1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index a7f9c3e..2992ce4 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -1085,6 +1085,16 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
>   	return ret;
>   }
>   
> +static unsigned long iommu_dma_get_merge_boundary(struct device *dev)
> +{
> +	struct iommu_domain *domain = iommu_get_dma_domain(dev);
> +
> +	if (domain->type != IOMMU_DOMAIN_DMA)

Did you actually need this check? In principle, if the default domain is 
not of type IOMMU_DOMAIN_DMA then the device should be assigned 
dma_direct_ops rather than iommu_dma_ops, thus it shouldn't be possible 
to get here. If you did manage to hit a case where the domain type 
didn't match the ops it would be interesting to figure out how.

Robin.

> +		return 0;	/* can't merge */
> +
> +	return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
> +}
> +
>   static const struct dma_map_ops iommu_dma_ops = {
>   	.alloc			= iommu_dma_alloc,
>   	.free			= iommu_dma_free,
> @@ -1100,6 +1110,7 @@ static const struct dma_map_ops iommu_dma_ops = {
>   	.sync_sg_for_device	= iommu_dma_sync_sg_for_device,
>   	.map_resource		= iommu_dma_map_resource,
>   	.unmap_resource		= iommu_dma_unmap_resource,
> +	.get_merge_boundary	= iommu_dma_get_merge_boundary,
>   };
>   
>   /*
>
Yoshihiro Shimoda Aug. 20, 2019, 1:42 a.m. UTC | #4 
Hi Robin,

> From: Robin Murphy, Sent: Monday, August 19, 2019 9:55 PM
> 
> On 26/07/2019 09:31, Yoshihiro Shimoda wrote:
> > This patch adds a new dma_map_ops of get_merge_boundary() to
> > expose the DMA merge boundary if the domain type is IOMMU_DOMAIN_DMA.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
> > ---
> >   drivers/iommu/dma-iommu.c | 11 +++++++++++
> >   1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > index a7f9c3e..2992ce4 100644
> > --- a/drivers/iommu/dma-iommu.c
> > +++ b/drivers/iommu/dma-iommu.c
> > @@ -1085,6 +1085,16 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
> >   	return ret;
> >   }
> >
> > +static unsigned long iommu_dma_get_merge_boundary(struct device *dev)
> > +{
> > +	struct iommu_domain *domain = iommu_get_dma_domain(dev);
> > +
> > +	if (domain->type != IOMMU_DOMAIN_DMA)
> 
> Did you actually need this check? In principle, if the default domain is
> not of type IOMMU_DOMAIN_DMA then the device should be assigned
> dma_direct_ops rather than iommu_dma_ops, thus it shouldn't be possible
> to get here. If you did manage to hit a case where the domain type
> didn't match the ops it would be interesting to figure out how.

Thank you for your review! You're correct. The current dma-iommu.c sets
the iommu_dma_ops to the device dma_ops only when the type is IOMMU_DOMAIN_DMA
like below:
---
	if (domain->type == IOMMU_DOMAIN_DMA) {
		if (iommu_dma_init_domain(domain, dma_base, size, dev))
			goto out_err;
		dev->dma_ops = &iommu_dma_ops;
	}
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/iommu/dma-iommu.c#n1118
---

So, I'll remove this check.

Best regards,
Yoshihiro Shimoda

> Robin.
> 
> > +		return 0;	/* can't merge */
> > +
> > +	return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
> > +}
> > +
> >   static const struct dma_map_ops iommu_dma_ops = {
> >   	.alloc			= iommu_dma_alloc,
> >   	.free			= iommu_dma_free,
> > @@ -1100,6 +1110,7 @@ static const struct dma_map_ops iommu_dma_ops = {
> >   	.sync_sg_for_device	= iommu_dma_sync_sg_for_device,
> >   	.map_resource		= iommu_dma_map_resource,
> >   	.unmap_resource		= iommu_dma_unmap_resource,
> > +	.get_merge_boundary	= iommu_dma_get_merge_boundary,
> >   };
> >
> >   /*
> >
diff mbox series

Patch

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index a7f9c3e..2992ce4 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1085,6 +1085,16 @@  static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 	return ret;
 }
 
+static unsigned long iommu_dma_get_merge_boundary(struct device *dev)
+{
+	struct iommu_domain *domain = iommu_get_dma_domain(dev);
+
+	if (domain->type != IOMMU_DOMAIN_DMA)
+		return 0;	/* can't merge */
+
+	return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
+}
+
 static const struct dma_map_ops iommu_dma_ops = {
 	.alloc			= iommu_dma_alloc,
 	.free			= iommu_dma_free,
@@ -1100,6 +1110,7 @@  static const struct dma_map_ops iommu_dma_ops = {
 	.sync_sg_for_device	= iommu_dma_sync_sg_for_device,
 	.map_resource		= iommu_dma_map_resource,
 	.unmap_resource		= iommu_dma_unmap_resource,
+	.get_merge_boundary	= iommu_dma_get_merge_boundary,
 };
 
 /*