RE: [PATCH 2/3] iommu/fsl: Fix the device domain attach condition.

2014-07-04 Thread Varun Sethi


> -Original Message-
> From: Joerg Roedel [mailto:j...@8bytes.org]
> Sent: Friday, July 04, 2014 4:25 PM
> To: Sethi Varun-B16395
> Cc: io...@lists.linux-foundation.org; linux-ker...@vger.kernel.org;
> linuxppc-dev@lists.ozlabs.org; alex.william...@redhat.com
> Subject: Re: [PATCH 2/3] iommu/fsl: Fix the device domain attach
> condition.
> 
> Hmm,
> 
> On Tue, Jun 24, 2014 at 07:27:16PM +0530, Varun Sethi wrote:
> > -   old_domain_info = find_domain(dev);
> > +   old_domain_info = dev->archdata.iommu_domain;
> > if (old_domain_info && old_domain_info->domain != dma_domain) {
> > spin_unlock_irqrestore(&device_domain_lock, flags);
> > detach_device(dev, old_domain_info->domain);
> 
> Wouldn't this set dev->archdata.iommu_domain to NULL anyway, so that ...
> 
Not for the case where device has multiple LIODNs.

> > @@ -399,7 +394,7 @@ static void attach_device(struct fsl_dma_domain
> *dma_domain, int liodn, struct d
> >  * the info for the first LIODN as all
> >  * LIODNs share the same domain
> >  */
> > -   if (!old_domain_info)
> > +   if (!dev->archdata.iommu_domain)
> > dev->archdata.iommu_domain = info;
> 
> We already know that it _must_ be NULL here?
> 

That won't be true for devices having multiple LIODNs

> > spin_unlock_irqrestore(&device_domain_lock, flags);
> 
> This would shrink down the patch to:
> 
> diff --git a/drivers/iommu/fsl_pamu_domain.c
> b/drivers/iommu/fsl_pamu_domain.c index 93072ba..d21b554 100644
> --- a/drivers/iommu/fsl_pamu_domain.c
> +++ b/drivers/iommu/fsl_pamu_domain.c
> @@ -399,8 +399,7 @@ static void attach_device(struct fsl_dma_domain
> *dma_domain, int liodn, struct d
>* the info for the first LIODN as all
>* LIODNs share the same domain
>*/
> - if (!old_domain_info)
> - dev->archdata.iommu_domain = info;
> + dev->archdata.iommu_domain = info;

For devices having multiple LIODNs, we don't want to overwrite the info.

-Varun

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Re: [PATCH 2/3] iommu/fsl: Fix the device domain attach condition.

2014-07-04 Thread Joerg Roedel
Hmm,

On Tue, Jun 24, 2014 at 07:27:16PM +0530, Varun Sethi wrote:
> - old_domain_info = find_domain(dev);
> + old_domain_info = dev->archdata.iommu_domain;
>   if (old_domain_info && old_domain_info->domain != dma_domain) {
>   spin_unlock_irqrestore(&device_domain_lock, flags);
>   detach_device(dev, old_domain_info->domain);

Wouldn't this set dev->archdata.iommu_domain to NULL anyway, so that ...

> @@ -399,7 +394,7 @@ static void attach_device(struct fsl_dma_domain 
> *dma_domain, int liodn, struct d
>* the info for the first LIODN as all
>* LIODNs share the same domain
>*/
> - if (!old_domain_info)
> + if (!dev->archdata.iommu_domain)
>   dev->archdata.iommu_domain = info;

We already know that it _must_ be NULL here?

>   spin_unlock_irqrestore(&device_domain_lock, flags);

This would shrink down the patch to:

diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 93072ba..d21b554 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -399,8 +399,7 @@ static void attach_device(struct fsl_dma_domain 
*dma_domain, int liodn, struct d
 * the info for the first LIODN as all
 * LIODNs share the same domain
 */
-   if (!old_domain_info)
-   dev->archdata.iommu_domain = info;
+   dev->archdata.iommu_domain = info;
spin_unlock_irqrestore(&device_domain_lock, flags);
 
 }


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[PATCH 2/3] iommu/fsl: Fix the device domain attach condition.

2014-06-24 Thread Varun Sethi

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