diff mbox series

[v5,03/11] powerpc/pseries/iommu: Add iommu_pseries_alloc_table() helper

Message ID 20210716082755.428187-4-leobras.c@gmail.com (mailing list archive)
State Superseded, archived
Headers show
Series DDW + Indirect Mapping | expand
Related show

Commit Message

Leonardo Brás July 16, 2021, 8:27 a.m. UTC 
Creates a helper to allow allocating a new iommu_table without the need
to reallocate the iommu_group.

This will be helpful for replacing the iommu_table for the new DMA window,
after we remove the old one with iommu_tce_table_put().

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/platforms/pseries/iommu.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

Comments

Frederic Barrat July 19, 2021, 2:04 p.m. UTC | #1 
On 16/07/2021 10:27, Leonardo Bras wrote:
> Creates a helper to allow allocating a new iommu_table without the need
> to reallocate the iommu_group.
> 
> This will be helpful for replacing the iommu_table for the new DMA window,
> after we remove the old one with iommu_tce_table_put().
> 
> Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>   arch/powerpc/platforms/pseries/iommu.c | 25 ++++++++++++++-----------
>   1 file changed, 14 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
> index b1b8d12bab39..33d82865d6e6 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -53,28 +53,31 @@ enum {
>   	DDW_EXT_QUERY_OUT_SIZE = 2
>   };
>   
> -static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> +static struct iommu_table *iommu_pseries_alloc_table(int node)
>   {
> -	struct iommu_table_group *table_group;
>   	struct iommu_table *tbl;
>   
> -	table_group = kzalloc_node(sizeof(struct iommu_table_group), GFP_KERNEL,
> -			   node);
> -	if (!table_group)
> -		return NULL;
> -
>   	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL, node);
>   	if (!tbl)
> -		goto free_group;
> +		return NULL;
>   
>   	INIT_LIST_HEAD_RCU(&tbl->it_group_list);
>   	kref_init(&tbl->it_kref);
> +	return tbl;
> +}
>   
> -	table_group->tables[0] = tbl;
> +static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> +{
> +	struct iommu_table_group *table_group;
> +
> +	table_group = kzalloc_node(sizeof(*table_group), GFP_KERNEL, node);
> +	if (!table_group)
> +		return NULL;
>   
> -	return table_group;
> +	table_group->tables[0] = iommu_pseries_alloc_table(node);
> +	if (table_group->tables[0])
> +		return table_group;


Nitpick: for readability, we'd usually expect the error path to be 
detected with the if statement and keep going on the good path, and here 
the code does the opposite. No big deal though, so

Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>


>   
> -free_group:
>   	kfree(table_group);
>   	return NULL;
>   }
>
Leonardo Brás July 19, 2021, 6:47 p.m. UTC | #2 
On Mon, 2021-07-19 at 16:04 +0200, Frederic Barrat wrote:
> 
> 
> On 16/07/2021 10:27, Leonardo Bras wrote:
> > Creates a helper to allow allocating a new iommu_table without the
> > need
> > to reallocate the iommu_group.
> > 
> > This will be helpful for replacing the iommu_table for the new DMA
> > window,
> > after we remove the old one with iommu_tce_table_put().
> > 
> > Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
> > Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> > ---
> >   arch/powerpc/platforms/pseries/iommu.c | 25 ++++++++++++++-------
> > ----
> >   1 file changed, 14 insertions(+), 11 deletions(-)
> > 
> > diff --git a/arch/powerpc/platforms/pseries/iommu.c
> > b/arch/powerpc/platforms/pseries/iommu.c
> > index b1b8d12bab39..33d82865d6e6 100644
> > --- a/arch/powerpc/platforms/pseries/iommu.c
> > +++ b/arch/powerpc/platforms/pseries/iommu.c
> > @@ -53,28 +53,31 @@ enum {
> >         DDW_EXT_QUERY_OUT_SIZE = 2
> >   };
> >   
> > -static struct iommu_table_group *iommu_pseries_alloc_group(int
> > node)
> > +static struct iommu_table *iommu_pseries_alloc_table(int node)
> >   {
> > -       struct iommu_table_group *table_group;
> >         struct iommu_table *tbl;
> >   
> > -       table_group = kzalloc_node(sizeof(struct
> > iommu_table_group), GFP_KERNEL,
> > -                          node);
> > -       if (!table_group)
> > -               return NULL;
> > -
> >         tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
> > node);
> >         if (!tbl)
> > -               goto free_group;
> > +               return NULL;
> >   
> >         INIT_LIST_HEAD_RCU(&tbl->it_group_list);
> >         kref_init(&tbl->it_kref);
> > +       return tbl;
> > +}
> >   
> > -       table_group->tables[0] = tbl;
> > +static struct iommu_table_group *iommu_pseries_alloc_group(int
> > node)
> > +{
> > +       struct iommu_table_group *table_group;
> > +
> > +       table_group = kzalloc_node(sizeof(*table_group),
> > GFP_KERNEL, node);
> > +       if (!table_group)
> > +               return NULL;
> >   
> > -       return table_group;
> > +       table_group->tables[0] = iommu_pseries_alloc_table(node);
> > +       if (table_group->tables[0])
> > +               return table_group;
> 
> 
> Nitpick: for readability, we'd usually expect the error path to be 
> detected with the if statement and keep going on the good path, and
> here 
> the code does the opposite. No big deal though, so
> 
> Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
> 
> 

Thanks for the tip and review!

Best regards,
Leonardo Bras


> >   
> > -free_group:
> >         kfree(table_group);
> >         return NULL;
> >   }
> >
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index b1b8d12bab39..33d82865d6e6 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -53,28 +53,31 @@  enum {
 	DDW_EXT_QUERY_OUT_SIZE = 2
 };
 
-static struct iommu_table_group *iommu_pseries_alloc_group(int node)
+static struct iommu_table *iommu_pseries_alloc_table(int node)
 {
-	struct iommu_table_group *table_group;
 	struct iommu_table *tbl;
 
-	table_group = kzalloc_node(sizeof(struct iommu_table_group), GFP_KERNEL,
-			   node);
-	if (!table_group)
-		return NULL;
-
 	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL, node);
 	if (!tbl)
-		goto free_group;
+		return NULL;
 
 	INIT_LIST_HEAD_RCU(&tbl->it_group_list);
 	kref_init(&tbl->it_kref);
+	return tbl;
+}
 
-	table_group->tables[0] = tbl;
+static struct iommu_table_group *iommu_pseries_alloc_group(int node)
+{
+	struct iommu_table_group *table_group;
+
+	table_group = kzalloc_node(sizeof(*table_group), GFP_KERNEL, node);
+	if (!table_group)
+		return NULL;
 
-	return table_group;
+	table_group->tables[0] = iommu_pseries_alloc_table(node);
+	if (table_group->tables[0])
+		return table_group;
 
-free_group:
 	kfree(table_group);
 	return NULL;
 }