[RFC PATCH 23/30] iommu/arm-smmu-v3: Bind/unbind device and task

Jean-Philippe Brucker
2017-02-27T19:54:34Z

Now that everything is in place, implement bind and unbind operations.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
---
drivers/iommu/arm-smmu-v3.c | 178 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 175 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 5e0008ac68cb..3ba7f65020f9 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -742,6 +742,7 @@ struct arm_smmu_master_data {

bool can_fault;
u32 avail_contexts;
+ const struct iommu_svm_ops *svm_ops;
};

/* SMMU private data for an IOMMU domain */
@@ -820,6 +821,7 @@ struct arm_smmu_context {

struct arm_smmu_task *task;
struct arm_smmu_master_data *master;
+ void *priv;

struct list_head task_head;
struct rb_node master_node;
@@ -2085,6 +2087,26 @@ static size_t arm_smmu_atc_invalidate_task(struct arm_smmu_task *smmu_task,
return size;
}

+static size_t arm_smmu_atc_invalidate_context(struct arm_smmu_context *smmu_context,
+ unsigned long iova, size_t size)
+{
+ struct arm_smmu_cmdq_ent cmd;
+ struct arm_smmu_device *smmu = smmu_context->master->smmu;
+ struct arm_smmu_cmdq_ent sync_cmd = {
+ .opcode = CMDQ_OP_CMD_SYNC,
+ };
+
+ arm_smmu_atc_invalidate_to_cmd(smmu, iova, size, &cmd);
+
+ cmd.substream_valid = true;
+ cmd.atc.ssid = smmu_context->ssid;
+
+ arm_smmu_atc_invalidate_master(smmu_context->master, &cmd);
+ arm_smmu_cmdq_issue_cmd(smmu, &sync_cmd);
+
+ return size;
+}
+
/* IOMMU API */
static bool arm_smmu_capable(enum iommu_cap cap)
{
@@ -2098,7 +2120,6 @@ static bool arm_smmu_capable(enum iommu_cap cap)
}
}

-__maybe_unused
static struct arm_smmu_context *
arm_smmu_attach_task(struct arm_smmu_task *smmu_task,
struct arm_smmu_master_data *master)
@@ -2444,7 +2465,6 @@ static void arm_smmu_free_task_pgtable(struct arm_smmu_task *smmu_task)
arm_smmu_bitmap_free(smmu->asid_map, smmu_task->s1_cfg.asid);
}

-__maybe_unused
static struct arm_smmu_task *arm_smmu_alloc_task(struct arm_smmu_device *smmu,
struct task_struct *task)
{
@@ -2741,7 +2761,156 @@ static void arm_smmu_handle_fault(struct work_struct *work)

static bool arm_smmu_master_supports_svm(struct arm_smmu_master_data *master)
{
- return false;
+ return dev_is_pci(master->dev) && master->can_fault &&
+ master->avail_contexts;
+}
+
+static int arm_smmu_set_svm_ops(struct device *dev,
+ const struct iommu_svm_ops *svm_ops)
+{
+ struct arm_smmu_master_data *master;
+
+ if (!dev->iommu_fwspec)
+ return -EINVAL;
+
+ master = dev->iommu_fwspec->iommu_priv;
+ if (!master)
+ return -EINVAL;
+
+ master->svm_ops = svm_ops;
+
+ return 0;
+}
+
+static int arm_smmu_bind_task(struct device *dev, struct task_struct *task,
+ int *pasid, int flags, void *priv)
+{
+ int ret = 0;
+ struct pid *pid;
+ struct iommu_group *group;
+ struct arm_smmu_device *smmu;
+ struct arm_smmu_group *smmu_group;
+ struct arm_smmu_domain *smmu_domain;
+ struct arm_smmu_master_data *master;
+ struct arm_smmu_task *smmu_task = NULL, *cur_task;
+ struct arm_smmu_context *smmu_context = NULL, *cur_context;
+
+ if (!dev->iommu_fwspec)
+ return -EINVAL;
+
+ master = dev->iommu_fwspec->iommu_priv;
+ if (!master)
+ return -EINVAL;
+
+ if (!arm_smmu_master_supports_svm(master))
+ return -EINVAL;
+
+ smmu = master->smmu;
+
+ group = iommu_group_get(dev);
+ smmu_group = to_smmu_group(group);
+
+ smmu_domain = smmu_group->domain;
+ if (!smmu_domain) {
+ iommu_group_put(group);
+ return -EINVAL;
+ }
+
+ if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1) {
+ /* We do not support stage-2 SVM yet... */
+ iommu_group_put(group);
+ return -ENOSYS;
+ }
+
+ iommu_group_put(group);
+
+ pid = get_task_pid(task, PIDTYPE_PID);
+
+ spin_lock(&smmu->contexts_lock);
+
+ list_for_each_entry(cur_task, &smmu->tasks, smmu_head) {
+ if (cur_task->pid == pid) {
+ kref_get(&cur_task->kref);
+ smmu_task = cur_task;
+ break;
+ }
+ }
+
+ if (smmu_task) {
+ list_for_each_entry(cur_context, &smmu_task->contexts,
+ task_head) {
+ if (cur_context->master->dev == dev) {
+ smmu_context = cur_context;
+ _arm_smmu_put_task(cur_task);
+ break;
+ }
+ }
+ }
+ spin_unlock(&smmu->contexts_lock);
+
+ put_pid(pid);
+
+ if (smmu_context)
+ /* We don't support nested bind/unbind calls */
+ return -EEXIST;
+
+ if (!smmu_task) {
+ smmu_task = arm_smmu_alloc_task(smmu, task);
+ if (IS_ERR(smmu_task))
+ return -PTR_ERR(smmu_task);
+ }
+
+ smmu_context = arm_smmu_attach_task(smmu_task, master);
+ if (IS_ERR(smmu_context)) {
+ arm_smmu_put_task(smmu, smmu_task);
+ return PTR_ERR(smmu_context);
+ }
+
+ smmu_context->priv = priv;
+
+ *pasid = smmu_context->ssid;
+ dev_dbg(dev, "bound to task %d with PASID %d\n", pid_vnr(pid), *pasid);
+
+ return ret;
+}
+
+static int arm_smmu_unbind_task(struct device *dev, int pasid, int flags)
+{
+ struct arm_smmu_device *smmu;
+ struct arm_smmu_master_data *master;
+ struct arm_smmu_context *smmu_context = NULL;
+
+ if (!dev->iommu_fwspec)
+ return -EINVAL;
+
+ master = dev->iommu_fwspec->iommu_priv;
+ if (!master)
+ return -EINVAL;
+
+ smmu = master->smmu;
+
+ smmu_context = arm_smmu_get_context_by_id(smmu, master, 0, pasid);
+ if (!smmu_context)
+ return -ESRCH;
+
+ dev_dbg(dev, "unbind PASID %d\n", pasid);
+
+ /*
+ * There isn't any "ATC invalidate all by PASID" command. If this isn't
+ * good enough, we'll need fine-grained invalidation for each vma.
+ */
+ arm_smmu_atc_invalidate_context(smmu_context, 0, -1);
+
+ spin_lock(&smmu->contexts_lock);
+ if (smmu_context->task)
+ arm_smmu_detach_task(smmu_context);
+
+ /* Release the ref we got earlier in this function */
+ _arm_smmu_put_context(smmu_context);
+ _arm_smmu_put_context(smmu_context);
+ spin_unlock(&smmu->contexts_lock);
+
+ return 0;
}

static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
@@ -3626,6 +3795,9 @@ static struct iommu_ops arm_smmu_ops = {
.capable = arm_smmu_capable,
.domain_alloc = arm_smmu_domain_alloc,
.domain_free = arm_smmu_domain_free,
+ .set_svm_ops = arm_smmu_set_svm_ops,
+ .bind_task = arm_smmu_bind_task,
+ .unbind_task = arm_smmu_unbind_task,
.attach_dev = arm_smmu_attach_dev,
.map = arm_smmu_map,
.unmap = arm_smmu_unmap,
--
2.11.0