[PATCH 7/7] iommu/arm-smmu-v3: Use the new rb tree helpers
Mostafa Saleh
smostafa at google.com
Tue Jun 4 09:22:11 PDT 2024
Hi Jason,
On Mon, Jun 03, 2024 at 07:31:33PM -0300, Jason Gunthorpe wrote:
> Since v5.12 the rbtree has gained some simplifying helpers aimed at making
> rb tree users write less convoluted boiler plate code. Instead the caller
> provides a single comparison function and the helpers generate the prior
> open-coded stuff.
>
> Update smmu->streams to use rb_find_add() and rb_find().
>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
Reviewed-by: Mostafa Saleh <smostafa at google.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 68 ++++++++++-----------
> 1 file changed, 31 insertions(+), 37 deletions(-)
>
> 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 7a6c9aac4cd450..25bae0b05a488c 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -1667,26 +1667,37 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid)
> return 0;
> }
>
> +static int arm_smmu_streams_cmp_key(const void *lhs, const struct rb_node *rhs)
> +{
> + struct arm_smmu_stream *stream_rhs =
> + rb_entry(rhs, struct arm_smmu_stream, node);
> + const u32 *sid_lhs = lhs;
> +
> + if (*sid_lhs < stream_rhs->id)
> + return -1;
> + if (*sid_lhs > stream_rhs->id)
> + return 1;
> + return 0;
> +}
> +
> +static int arm_smmu_streams_cmp_node(struct rb_node *lhs,
> + const struct rb_node *rhs)
> +{
> + return arm_smmu_streams_cmp_key(
> + &rb_entry(lhs, struct arm_smmu_stream, node)->id, rhs);
> +}
> +
> 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;
>
> lockdep_assert_held(&smmu->streams_mutex);
>
> - 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;
> + node = rb_find(&sid, &smmu->streams, arm_smmu_streams_cmp_key);
> + if (!node)
> + return NULL;
> + return rb_entry(node, struct arm_smmu_stream, node)->master;
> }
>
> /* IRQ and event handlers */
> @@ -2795,8 +2806,6 @@ static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
> {
> 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),
> @@ -2807,9 +2816,9 @@ static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
>
> mutex_lock(&smmu->streams_mutex);
> for (i = 0; i < fwspec->num_ids; i++) {
> + struct arm_smmu_stream *new_stream = &master->streams[i];
> u32 sid = fwspec->ids[i];
>
> - new_stream = &master->streams[i];
> new_stream->id = sid;
> new_stream->master = master;
>
> @@ -2818,28 +2827,13 @@ static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
> 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)
> + if (rb_find_add(&new_stream->node, &smmu->streams,
> + arm_smmu_streams_cmp_node)) {
> + dev_warn(master->dev, "stream %u already in tree\n",
> + sid);
> + ret = -EINVAL;
> break;
> -
> - rb_link_node(&new_stream->node, parent_node, new_node);
> - rb_insert_color(&new_stream->node, &smmu->streams);
> + }
> }
>
> if (ret) {
> --
> 2.45.2
>
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