Please ignore this patch, wrong author name. Have reposted V4 with correct author name. Sorry.
Regards, Peng. On Fri, Nov 20, 2015 at 04:54:10PM +0800, Freenix wrote: >The basic flow for add a device: > arm_smmu_add_device > |->iommu_group_get_for_dev > |->iommu_group_get > return group; (1) > |->ops->device_group : Init/increase reference count to/by 1. > |->iommu_group_add_device : Increase reference count by 1. > return group (2) > |->return 0; > >Since we are adding one device, the flow is (2) and the group reference >count will be increased by 2. So, we need to add iommu_group_put at the >end of arm_smmu_add_device to decrease the count by 1. > >Also take the failure path into consideration when fail to add a device. > >Signed-off-by: Peng Fan <[email protected]> >Cc: Will Deacon <[email protected]> >--- > >V3 thread: https://lkml.org/lkml/2015/11/9/842 >Changes V4: > Follow Will's comments and code diff, add the failure path when failed > to add a device. > >V2 thread: https://lkml.org/lkml/2015/11/9/39 >Changes V3: > This patch version is wrong to fix the group reference issue. > >V1 thread: https://lkml.org/lkml/2015/11/3/304 >Changes V2: > I did not see the update about device_group when I worked out V1. So > redo the patch and refine commit msg and rebased to latest linus' > linux master tree. > > drivers/iommu/arm-smmu-v3.c | 18 +++++++++++------- > drivers/iommu/arm-smmu.c | 2 ++ > 2 files changed, 13 insertions(+), 7 deletions(-) > >diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c >index 4e5118a..42d30ef 100644 >--- a/drivers/iommu/arm-smmu-v3.c >+++ b/drivers/iommu/arm-smmu-v3.c >@@ -1804,13 +1804,13 @@ static int arm_smmu_add_device(struct device *dev) > smmu = arm_smmu_get_for_pci_dev(pdev); > if (!smmu) { > ret = -ENOENT; >- goto out_put_group; >+ goto out_remove_dev; > } > > smmu_group = kzalloc(sizeof(*smmu_group), GFP_KERNEL); > if (!smmu_group) { > ret = -ENOMEM; >- goto out_put_group; >+ goto out_remove_dev; > } > > smmu_group->ste.valid = true; >@@ -1826,20 +1826,20 @@ static int arm_smmu_add_device(struct device *dev) > for (i = 0; i < smmu_group->num_sids; ++i) { > /* If we already know about this SID, then we're done */ > if (smmu_group->sids[i] == sid) >- return 0; >+ goto out_put_group; > } > > /* Check the SID is in range of the SMMU and our stream table */ > if (!arm_smmu_sid_in_range(smmu, sid)) { > ret = -ERANGE; >- goto out_put_group; >+ goto out_remove_dev; > } > > /* Ensure l2 strtab is initialised */ > if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) { > ret = arm_smmu_init_l2_strtab(smmu, sid); > if (ret) >- goto out_put_group; >+ goto out_remove_dev; > } > > /* Resize the SID array for the group */ >@@ -1849,16 +1849,20 @@ static int arm_smmu_add_device(struct device *dev) > if (!sids) { > smmu_group->num_sids--; > ret = -ENOMEM; >- goto out_put_group; >+ goto out_remove_dev; > } > > /* Add the new SID */ > sids[smmu_group->num_sids - 1] = sid; > smmu_group->sids = sids; >- return 0; > > out_put_group: > iommu_group_put(group); >+ return 0; >+ >+out_remove_dev: >+ iommu_group_remove_device(dev); >+ iommu_group_put(group); > return ret; > } > >diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >index 47dc7a7..af6afce 100644 >--- a/drivers/iommu/arm-smmu.c >+++ b/drivers/iommu/arm-smmu.c >@@ -1357,6 +1357,8 @@ static int arm_smmu_add_device(struct device *dev) > if (IS_ERR(group)) > return PTR_ERR(group); > >+ iommu_group_put(group); >+ > return 0; > } > >-- >2.6.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
