Re: [PATCH v2 7/8] iommu/arm-smmu-v3: Improve add_device() error handling

2019-11-11 Thread Jonathan Cameron
On Fri, 8 Nov 2019 16:25:07 +0100
Jean-Philippe Brucker  wrote:

> Let add_device() clean up after itself. The iommu_bus_init() function
> does call remove_device() on error, but other sites (e.g. of_iommu) do
> not.
> 
> Don't free level-2 stream tables because we'd have to track if we
> allocated each of them or if they are used by other endpoints. It's not
> worth the hassle since they are managed resources.
> 
> Reviewed-by: Eric Auger 
> Signed-off-by: Jean-Philippe Brucker 

Potentially some fun around reordering of last few actions, but
doesn't seem there is any real connection between them so should be
fine.

Reviewed-by: Jonathan Cameron 

> ---
>  drivers/iommu/arm-smmu-v3.c | 28 +---
>  1 file changed, 21 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 82eac89ee187..88ec0bf33492 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2826,14 +2826,16 @@ static int arm_smmu_add_device(struct device *dev)
>   for (i = 0; i < master->num_sids; i++) {
>   u32 sid = master->sids[i];
>  
> - if (!arm_smmu_sid_in_range(smmu, sid))
> - return -ERANGE;
> + if (!arm_smmu_sid_in_range(smmu, sid)) {
> + ret = -ERANGE;
> + goto err_free_master;
> + }
>  
>   /* Ensure l2 strtab is initialised */
>   if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
>   ret = arm_smmu_init_l2_strtab(smmu, sid);
>   if (ret)
> - return ret;
> + goto err_free_master;
>   }
>   }
>  
> @@ -2843,13 +2845,25 @@ static int arm_smmu_add_device(struct device *dev)
>   master->ssid_bits = min_t(u8, master->ssid_bits,
> CTXDESC_LINEAR_CDMAX);
>  
> + ret = iommu_device_link(>iommu, dev);
> + if (ret)
> + goto err_free_master;
> +
>   group = iommu_group_get_for_dev(dev);
> - if (!IS_ERR(group)) {
> - iommu_group_put(group);
> - iommu_device_link(>iommu, dev);
> + if (IS_ERR(group)) {
> + ret = PTR_ERR(group);
> + goto err_unlink;
>   }
>  
> - return PTR_ERR_OR_ZERO(group);
> + iommu_group_put(group);
> + return 0;
> +
> +err_unlink:
> + iommu_device_unlink(>iommu, dev);
> +err_free_master:
> + kfree(master);
> + fwspec->iommu_priv = NULL;
> + return ret;
>  }
>  
>  static void arm_smmu_remove_device(struct device *dev)


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[PATCH v2 7/8] iommu/arm-smmu-v3: Improve add_device() error handling

2019-11-08 Thread Jean-Philippe Brucker
Let add_device() clean up after itself. The iommu_bus_init() function
does call remove_device() on error, but other sites (e.g. of_iommu) do
not.

Don't free level-2 stream tables because we'd have to track if we
allocated each of them or if they are used by other endpoints. It's not
worth the hassle since they are managed resources.

Reviewed-by: Eric Auger 
Signed-off-by: Jean-Philippe Brucker 
---
 drivers/iommu/arm-smmu-v3.c | 28 +---
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 82eac89ee187..88ec0bf33492 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2826,14 +2826,16 @@ static int arm_smmu_add_device(struct device *dev)
for (i = 0; i < master->num_sids; i++) {
u32 sid = master->sids[i];
 
-   if (!arm_smmu_sid_in_range(smmu, sid))
-   return -ERANGE;
+   if (!arm_smmu_sid_in_range(smmu, sid)) {
+   ret = -ERANGE;
+   goto err_free_master;
+   }
 
/* Ensure l2 strtab is initialised */
if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
ret = arm_smmu_init_l2_strtab(smmu, sid);
if (ret)
-   return ret;
+   goto err_free_master;
}
}
 
@@ -2843,13 +2845,25 @@ static int arm_smmu_add_device(struct device *dev)
master->ssid_bits = min_t(u8, master->ssid_bits,
  CTXDESC_LINEAR_CDMAX);
 
+   ret = iommu_device_link(>iommu, dev);
+   if (ret)
+   goto err_free_master;
+
group = iommu_group_get_for_dev(dev);
-   if (!IS_ERR(group)) {
-   iommu_group_put(group);
-   iommu_device_link(>iommu, dev);
+   if (IS_ERR(group)) {
+   ret = PTR_ERR(group);
+   goto err_unlink;
}
 
-   return PTR_ERR_OR_ZERO(group);
+   iommu_group_put(group);
+   return 0;
+
+err_unlink:
+   iommu_device_unlink(>iommu, dev);
+err_free_master:
+   kfree(master);
+   fwspec->iommu_priv = NULL;
+   return ret;
 }
 
 static void arm_smmu_remove_device(struct device *dev)
-- 
2.23.0

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