Hi Keqian,

On 2/1/21 1:26 PM, Keqian Zhu wrote:
> Hi Eric,
> 
> On 2020/11/18 19:21, Eric Auger wrote:
>> From: Jean-Philippe Brucker <jean-phili...@linaro.org>
>>
>> When handling faults from the event or PRI queue, we need to find the
>> struct device associated to a SID. Add a rb_tree to keep track of SIDs.
>>
>> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
> [...]
> 
>>  }
>>  
>> +static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
>> +                              struct arm_smmu_master *master)
>> +{
>> +    int i;
>> +    int ret = 0;
>> +    struct arm_smmu_stream *new_stream, *cur_stream;
>> +    struct rb_node **new_node, *parent_node = NULL;
>> +    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(master->dev);
>> +
>> +    master->streams = kcalloc(fwspec->num_ids,
>> +                              sizeof(struct arm_smmu_stream), GFP_KERNEL);
>> +    if (!master->streams)
>> +            return -ENOMEM;
>> +    master->num_streams = fwspec->num_ids;
> This is not roll-backed when fail.
> 
>> +
>> +    mutex_lock(&smmu->streams_mutex);
>> +    for (i = 0; i < fwspec->num_ids && !ret; i++) {
> Check ret at here, makes it hard to decide the start index of rollback.
> 
> If we fail at here, then start index is (i-2).
> If we fail in the loop, then start index is (i-1).
> 
>> +            u32 sid = fwspec->ids[i];
>> +
>> +            new_stream = &master->streams[i];
>> +            new_stream->id = sid;
>> +            new_stream->master = master;
>> +
>> +            /*
>> +             * Check the SIDs are in range of the SMMU and our stream table
>> +             */
>> +            if (!arm_smmu_sid_in_range(smmu, sid)) {
>> +                    ret = -ERANGE;
>> +                    break;
>> +            }
>> +
>> +            /* Ensure l2 strtab is initialised */
>> +            if (smmu->features & ARM_SMMU_FEAT_2_LVL_STRTAB) {
>> +                    ret = arm_smmu_init_l2_strtab(smmu, sid);
>> +                    if (ret)
>> +                            break;
>> +            }
>> +
>> +            /* Insert into SID tree */
>> +            new_node = &(smmu->streams.rb_node);
>> +            while (*new_node) {
>> +                    cur_stream = rb_entry(*new_node, struct arm_smmu_stream,
>> +                                          node);
>> +                    parent_node = *new_node;
>> +                    if (cur_stream->id > new_stream->id) {
>> +                            new_node = &((*new_node)->rb_left);
>> +                    } else if (cur_stream->id < new_stream->id) {
>> +                            new_node = &((*new_node)->rb_right);
>> +                    } else {
>> +                            dev_warn(master->dev,
>> +                                     "stream %u already in tree\n",
>> +                                     cur_stream->id);
>> +                            ret = -EINVAL;
>> +                            break;
>> +                    }
>> +            }
>> +
>> +            if (!ret) {
>> +                    rb_link_node(&new_stream->node, parent_node, new_node);
>> +                    rb_insert_color(&new_stream->node, &smmu->streams);
>> +            }
>> +    }
>> +
>> +    if (ret) {
>> +            for (; i > 0; i--)
> should be (i >= 0)?
> And the start index seems not correct.
> 
>> +                    rb_erase(&master->streams[i].node, &smmu->streams);
>> +            kfree(master->streams);
>> +    }
>> +    mutex_unlock(&smmu->streams_mutex);
>> +
>> +    return ret;
>> +}
>> +
>> +static void arm_smmu_remove_master(struct arm_smmu_master *master)
>> +{
>> +    int i;
>> +    struct arm_smmu_device *smmu = master->smmu;
>> +    struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(master->dev);
>> +
>> +    if (!smmu || !master->streams)
>> +            return;
>> +
>> +    mutex_lock(&smmu->streams_mutex);
>> +    for (i = 0; i < fwspec->num_ids; i++)
>> +            rb_erase(&master->streams[i].node, &smmu->streams);
>> +    mutex_unlock(&smmu->streams_mutex);
>> +
>> +    kfree(master->streams);
>> +}
>> +
>>  static struct iommu_ops arm_smmu_ops;
>>  
>>  static struct iommu_device *arm_smmu_probe_device(struct device *dev)
>>  {
>> -    int i, ret;
>> +    int ret;
>>      struct arm_smmu_device *smmu;
>>      struct arm_smmu_master *master;
>>      struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
>> @@ -2331,27 +2447,12 @@ static struct iommu_device 
>> *arm_smmu_probe_device(struct device *dev)
>>  
>>      master->dev = dev;
>>      master->smmu = smmu;
>> -    master->sids = fwspec->ids;
>> -    master->num_sids = fwspec->num_ids;
>>      INIT_LIST_HEAD(&master->bonds);
>>      dev_iommu_priv_set(dev, master);
>>  
>> -    /* Check the SIDs are in range of the SMMU and our stream table */
>> -    for (i = 0; i < master->num_sids; i++) {
>> -            u32 sid = master->sids[i];
>> -
>> -            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)
>> -                            goto err_free_master;
>> -            }
>> -    }
>> +    ret = arm_smmu_insert_master(smmu, master);
>> +    if (ret)
>> +            goto err_free_master;
>>  
>>      master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits);
>>  
>> @@ -2389,6 +2490,7 @@ static void arm_smmu_release_device(struct device *dev)
>>      WARN_ON(arm_smmu_master_sva_enabled(master));
>>      arm_smmu_detach_dev(master);
>>      arm_smmu_disable_pasid(master);
>> +    arm_smmu_remove_master(master);
>>      kfree(master);
> 
> Thanks,
> Keqian
> 
Thank you for the review. Jean will address this issues in his own
series and on my end I will rebase on this latter.

Best Regards

Eric


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