[PATCH 0/3] iommu/fsl: Fixes for the PAMU driver.

[PATCH 0/3] iommu/fsl: Fixes for the PAMU driver.

[Varun Sethi]

This patch set contains fixes for the PAMU driver. 
The patches are based on 3.16-rc1.

Varun Sethi (3):
  Fix PAMU window size check. 
  Fix the device domain attach condition.
  Fix the error condition during iommu group creation.

 drivers/iommu/fsl_pamu.c        |    8 ++++----
 drivers/iommu/fsl_pamu_domain.c |   19 +++++++++----------
 2 files changed, 13 insertions(+), 14 deletions(-)

-- 
1.7.9.5

[PATCH 1/3] iommu/fsl: Fix PAMU window size check.

[Varun Sethi]

is_power_of_2 requires an unsigned long parameter which would
lead to truncation of 64 bit values on 32 bit architectures.

__ffs also expects an unsigned long parameter thus won't work
for 64 bit values on 32 bit architectures.

Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
---
 drivers/iommu/fsl_pamu.c        |    8 ++++----
 drivers/iommu/fsl_pamu_domain.c |    2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/fsl_pamu.c b/drivers/iommu/fsl_pamu.c
index b99dd88..bb446d7 100644
--- a/drivers/iommu/fsl_pamu.c
+++ b/drivers/iommu/fsl_pamu.c
@@ -170,10 +170,10 @@ int pamu_disable_liodn(int liodn)
 static unsigned int map_addrspace_size_to_wse(phys_addr_t addrspace_size)
 {
 	/* Bug if not a power of 2 */
-	BUG_ON(!is_power_of_2(addrspace_size));
+	BUG_ON((addrspace_size & (addrspace_size - 1)));
 
 	/* window size is 2^(WSE+1) bytes */
-	return __ffs(addrspace_size) - 1;
+	return fls64(addrspace_size) - 2;
 }
 
 /* Derive the PAACE window count encoding for the subwindow count */
@@ -351,7 +351,7 @@ int pamu_config_ppaace(int liodn, phys_addr_t win_addr, phys_addr_t win_size,
 	struct paace *ppaace;
 	unsigned long fspi;
 
-	if (!is_power_of_2(win_size) || win_size < PAMU_PAGE_SIZE) {
+	if ((win_size & (win_size - 1)) || win_size < PAMU_PAGE_SIZE) {
 		pr_debug("window size too small or not a power of two %llx\n", win_size);
 		return -EINVAL;
 	}
@@ -464,7 +464,7 @@ int pamu_config_spaace(int liodn, u32 subwin_cnt, u32 subwin,
 		return -ENOENT;
 	}
 
-	if (!is_power_of_2(subwin_size) || subwin_size < PAMU_PAGE_SIZE) {
+	if ((subwin_size & (subwin_size - 1)) || subwin_size < PAMU_PAGE_SIZE) {
 		pr_debug("subwindow size out of range, or not a power of 2\n");
 		return -EINVAL;
 	}
diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 93072ba..3dd0b8e 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -301,7 +301,7 @@ static int check_size(u64 size, dma_addr_t iova)
 	 * Size must be a power of two and at least be equal
 	 * to PAMU page size.
 	 */
-	if (!is_power_of_2(size) || size < PAMU_PAGE_SIZE) {
+	if ((size & (size - 1)) || size < PAMU_PAGE_SIZE) {
 		pr_debug("%s: size too small or not a power of two\n", __func__);
 		return -EINVAL;
 	}
-- 
1.7.9.5

Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.

[Joerg Roedel]

On Tue, Jun 24, 2014 at 07:27:15PM +0530, Varun Sethi wrote:
>  	/* window size is 2^(WSE+1) bytes */
> -	return __ffs(addrspace_size) - 1;
> +	return fls64(addrspace_size) - 2;

This looks bogus, why do you replace ffs (find-first-bit) by fls
(find-last-bit)?


	Joerg

RE: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.

[Varun Sethi]

> -----Original Message-----
> From: Joerg Roedel [mailto:joro@8bytes.org]
> Sent: Friday, July 04, 2014 4:15 PM
> To: Sethi Varun-B16395
> Cc: iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org;
> linuxppc-dev@lists.ozlabs.org; alex.williamson@redhat.com
> Subject: Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.
>=20
> On Tue, Jun 24, 2014 at 07:27:15PM +0530, Varun Sethi wrote:
> >  	/* window size is 2^(WSE+1) bytes */
> > -	return __ffs(addrspace_size) - 1;
> > +	return fls64(addrspace_size) - 2;
>=20
> This looks bogus, why do you replace ffs (find-first-bit) by fls (find-
> last-bit)?
>=20
Address space size is always a power of 2. This change was required to hand=
le address sizes > 32bit width on 32 bit architectures.

-Varun

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

[Varun Sethi]

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

[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);
 
 }

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

[Varun Sethi]

> -----Original Message-----
> From: Joerg Roedel [mailto:joro@8bytes.org]
> Sent: Friday, July 04, 2014 4:25 PM
> To: Sethi Varun-B16395
> Cc: iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org;
> linuxppc-dev@lists.ozlabs.org; alex.williamson@redhat.com
> Subject: Re: [PATCH 2/3] iommu/fsl: Fix the device domain attach
> condition.
>=20
> Hmm,
>=20
> On Tue, Jun 24, 2014 at 07:27:16PM +0530, Varun Sethi wrote:
> > -	old_domain_info =3D find_domain(dev);
> > +	old_domain_info =3D dev->archdata.iommu_domain;
> >  	if (old_domain_info && old_domain_info->domain !=3D dma_domain) {
> >  		spin_unlock_irqrestore(&device_domain_lock, flags);
> >  		detach_device(dev, old_domain_info->domain);
>=20
> Wouldn't this set dev->archdata.iommu_domain to NULL anyway, so that ...
>=20
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 =3D info;
>=20
> We already know that it _must_ be NULL here?
>=20

That won't be true for devices having multiple LIODNs

> >  	spin_unlock_irqrestore(&device_domain_lock, flags);
>=20
> This would shrink down the patch to:
>=20
> 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 =3D info;
> +	dev->archdata.iommu_domain =3D info;

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

-Varun

[PATCH 3/3] iommu/fsl: Fix the error condition during iommu group

[Varun Sethi]

Earlier PTR_ERR was being returned even if group was set to null.
Now, we explicitly set an ERR_PTR value in case the group  pointer is
NULL.

Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
---
 drivers/iommu/fsl_pamu_domain.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 54060d1..af47648 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -1037,12 +1037,15 @@ root_bus:
 			group = get_shared_pci_device_group(pdev);
 	}
 
+	if (!group)
+		group = ERR_PTR(-ENODEV);
+
 	return group;
 }
 
 static int fsl_pamu_add_device(struct device *dev)
 {
-	struct iommu_group *group = NULL;
+	struct iommu_group *group = ERR_PTR(-ENODEV);
 	struct pci_dev *pdev;
 	const u32 *prop;
 	int ret, len;
@@ -1065,7 +1068,7 @@ static int fsl_pamu_add_device(struct device *dev)
 			group = get_device_iommu_group(dev);
 	}
 
-	if (!group || IS_ERR(group))
+	if (IS_ERR(group))
 		return PTR_ERR(group);
 
 	ret = iommu_group_add_device(group, dev);
-- 
1.7.9.5

Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.

[Emil Medve]

On 06/24/2014 08:57 AM, Varun Sethi wrote:
> is_power_of_2 requires an unsigned long parameter which would
> lead to truncation of 64 bit values on 32 bit architectures.
> 
> __ffs also expects an unsigned long parameter thus won't work
> for 64 bit values on 32 bit architectures.
> 
> Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
> ---
>  drivers/iommu/fsl_pamu.c        |    8 ++++----
>  drivers/iommu/fsl_pamu_domain.c |    2 +-
>  2 files changed, 5 insertions(+), 5 deletions(-)

Tested-by: Emil Medve <Emilian.Medve@Freescale.com>

On a P4080 DS (i.e. 32-bit SoC)


Cheers,

RE: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.

[Varun Sethi]

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Re: [PATCH 0/3] iommu/fsl: Fixes for the PAMU driver.

[Joerg Roedel]

On Tue, Jun 24, 2014 at 07:27:14PM +0530, Varun Sethi wrote:
> This patch set contains fixes for the PAMU driver. 
> The patches are based on 3.16-rc1.
> 
> Varun Sethi (3):
>   Fix PAMU window size check. 
>   Fix the device domain attach condition.
>   Fix the error condition during iommu group creation.
> 
>  drivers/iommu/fsl_pamu.c        |    8 ++++----
>  drivers/iommu/fsl_pamu_domain.c |   19 +++++++++----------
>  2 files changed, 13 insertions(+), 14 deletions(-)

Applied to iommu/fixes, thanks.

RE: [PATCH 0/3] iommu/fsl: Fixes for the PAMU driver.

[Varun Sethi]

Thanks Joerg.

> -----Original Message-----
> From: Joerg Roedel [mailto:joro@8bytes.org]
> Sent: Monday, July 07, 2014 2:02 PM
> To: Sethi Varun-B16395
> Cc: iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org;
> linuxppc-dev@lists.ozlabs.org; alex.williamson@redhat.com
> Subject: Re: [PATCH 0/3] iommu/fsl: Fixes for the PAMU driver.
>=20
> On Tue, Jun 24, 2014 at 07:27:14PM +0530, Varun Sethi wrote:
> > This patch set contains fixes for the PAMU driver.
> > The patches are based on 3.16-rc1.
> >
> > Varun Sethi (3):
> >   Fix PAMU window size check.
> >   Fix the device domain attach condition.
> >   Fix the error condition during iommu group creation.
> >
> >  drivers/iommu/fsl_pamu.c        |    8 ++++----
> >  drivers/iommu/fsl_pamu_domain.c |   19 +++++++++----------
> >  2 files changed, 13 insertions(+), 14 deletions(-)
>=20
> Applied to iommu/fixes, thanks.
>=20