On Tue, Mar 02, 2021 at 10:26:43AM +0100, Jean-Philippe Brucker wrote:
> When handling faults from the event or PRI queue, we need to find the
> struct device associated with a SID. Add a rb_tree to keep track of
> SIDs.
>
> Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 13 +-
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 157 ++++++++++++++++----
> 2 files changed, 140 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> index f985817c967a..7b15b7580c6e 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -639,6 +639,15 @@ struct arm_smmu_device {
>
> /* IOMMU core code handle */
> struct iommu_device iommu;
> +
> + struct rb_root streams;
> + struct mutex streams_mutex;
> +};
> +
> +struct arm_smmu_stream {
> + u32 id;
> + struct arm_smmu_master *master;
> + struct rb_node node;
> };
>
> /* SMMU private data for each master */
> @@ -647,8 +656,8 @@ struct arm_smmu_master {
> struct device *dev;
> struct arm_smmu_domain *domain;
> struct list_head domain_head;
> - u32 *sids;
> - unsigned int num_sids;
> + struct arm_smmu_stream *streams;
> + unsigned int num_streams;
> bool ats_enabled;
> bool sva_enabled;
> struct list_head bonds;
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 7edce914c45e..d148bb6d4289 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -909,8 +909,8 @@ static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain,
>
> spin_lock_irqsave(&smmu_domain->devices_lock, flags);
> list_for_each_entry(master, &smmu_domain->devices, domain_head) {
> - for (i = 0; i < master->num_sids; i++) {
> - cmd.cfgi.sid = master->sids[i];
> + for (i = 0; i < master->num_streams; i++) {
> + cmd.cfgi.sid = master->streams[i].id;
> arm_smmu_cmdq_batch_add(smmu, &cmds, &cmd);
> }
> }
> @@ -1355,6 +1355,28 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid)
> return 0;
> }
>
> +/* smmu->streams_mutex must be held */
Can you add a lockdep assertion for that?
> +__maybe_unused
> +static struct arm_smmu_master *
> +arm_smmu_find_master(struct arm_smmu_device *smmu, u32 sid)
> +{
> + struct rb_node *node;
> + struct arm_smmu_stream *stream;
> +
> + node = smmu->streams.rb_node;
> + while (node) {
> + stream = rb_entry(node, struct arm_smmu_stream, node);
> + if (stream->id < sid)
> + node = node->rb_right;
> + else if (stream->id > sid)
> + node = node->rb_left;
> + else
> + return stream->master;
> + }
> +
> + return NULL;
> +}
[...]
> +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(*master->streams),
> + GFP_KERNEL);
> + if (!master->streams)
> + return -ENOMEM;
> + master->num_streams = fwspec->num_ids;
> +
> + mutex_lock(&smmu->streams_mutex);
> + for (i = 0; i < fwspec->num_ids; i++) {
> + 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)
> + break;
> +
> + rb_link_node(&new_stream->node, parent_node, new_node);
> + rb_insert_color(&new_stream->node, &smmu->streams);
> + }
> +
> + if (ret) {
> + for (i--; i >= 0; i--)
Is 'i--' really what you want for the initial value? Doesn't that correspond
to the ID you *didn't* add to the tree?
> + rb_erase(&master->streams[i].node, &smmu->streams);
> + kfree(master->streams);
Do you need to NULLify master->streams and/or reset master->num_streams
after this? Seems like they're left dangling.
Will
