[PATCH v7 11/23] iommu/arm-smmu-v3: Maintain a SID->device structure

Eric Auger
2019-04-08T12:18:59Z

From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>

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-philippe.brucker@arm.com>
---
drivers/iommu/arm-smmu-v3.c | 136 ++++++++++++++++++++++++++++++++++--
1 file changed, 132 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index ff998c967a0a..21d027695181 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -588,6 +588,16 @@ 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_data *master;
+ struct rb_node node;
};

/* SMMU private data for each master */
@@ -597,6 +607,7 @@ struct arm_smmu_master_data {

struct arm_smmu_domain *domain;
struct list_head list; /* domain->devices */
+ struct arm_smmu_stream *streams;

struct device *dev;
};
@@ -1243,6 +1254,32 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid)
return 0;
}

+__maybe_unused
+static struct arm_smmu_master_data *
+arm_smmu_find_master(struct arm_smmu_device *smmu, u32 sid)
+{
+ struct rb_node *node;
+ struct arm_smmu_stream *stream;
+ struct arm_smmu_master_data *master = NULL;
+
+ mutex_lock(&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 {
+ master = stream->master;
+ break;
+ }
+ }
+ mutex_unlock(&smmu->streams_mutex);
+
+ return master;
+}
+
/* IRQ and event handlers */
static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev)
{
@@ -1881,6 +1918,71 @@ static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
return sid < limit;
}

+static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
+ struct arm_smmu_master_data *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 = master->dev->iommu_fwspec;
+
+ master->streams = kcalloc(fwspec->num_ids,
+ sizeof(struct arm_smmu_stream), GFP_KERNEL);
+ if (!master->streams)
+ return -ENOMEM;
+
+ mutex_lock(&smmu->streams_mutex);
+ for (i = 0; i < fwspec->num_ids && !ret; i++) {
+ new_stream = &master->streams[i];
+ new_stream->id = fwspec->ids[i];
+ new_stream->master = master;
+
+ 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);
+ }
+ }
+ mutex_unlock(&smmu->streams_mutex);
+
+ return ret;
+}
+
+static void arm_smmu_remove_master(struct arm_smmu_device *smmu,
+ struct arm_smmu_master_data *master)
+{
+ int i;
+ struct iommu_fwspec *fwspec = master->dev->iommu_fwspec;
+
+ if (!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 int arm_smmu_add_device(struct device *dev)
@@ -1929,13 +2031,35 @@ static int arm_smmu_add_device(struct device *dev)
}
}

+ ret = iommu_device_link(&smmu->iommu, dev);
+ if (ret)
+ goto err_free_master;
+
+ ret = arm_smmu_insert_master(smmu, master);
+ if (ret)
+ goto err_unlink;
+
group = iommu_group_get_for_dev(dev);
- if (!IS_ERR(group)) {
- iommu_group_put(group);
- iommu_device_link(&smmu->iommu, dev);
+ if (IS_ERR(group)) {
+ ret = PTR_ERR(group);
+ goto err_remove_master;
}

- return PTR_ERR_OR_ZERO(group);
+ iommu_group_put(group);
+
+ return 0;
+
+err_remove_master:
+ arm_smmu_remove_master(smmu, master);
+
+err_unlink:
+ iommu_device_unlink(&smmu->iommu, dev);
+
+err_free_master:
+ kfree(master);
+ fwspec->iommu_priv = NULL;
+
+ return ret;
}

static void arm_smmu_remove_device(struct device *dev)
@@ -1952,6 +2076,7 @@ static void arm_smmu_remove_device(struct device *dev)
if (master && master->ste.assigned)
arm_smmu_detach_dev(dev);
iommu_group_remove_device(dev);
+ arm_smmu_remove_master(smmu, master);
iommu_device_unlink(&smmu->iommu, dev);
kfree(master);
iommu_fwspec_free(dev);
@@ -2265,6 +2390,9 @@ static int arm_smmu_init_structures(struct arm_smmu_device *smmu)
{
int ret;

+ mutex_init(&smmu->streams_mutex);
+ smmu->streams = RB_ROOT;
+
ret = arm_smmu_init_queues(smmu);
if (ret)
return ret;
--
2.20.1