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[RFC PATCH 01/21] xen/arm: smmuv3: Maintain a SID->device structure



From: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>

Backport Linux commit cdf315f907d4. This is the clean backport without
any changes.

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>
Reviewed-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210401154718.307519-8-jean-philippe@xxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 
cdf315f907d4
Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
---
 xen/drivers/passthrough/arm/smmu-v3.c | 131 +++++++++++++++++++++-----
 xen/drivers/passthrough/arm/smmu-v3.h |  13 ++-
 2 files changed, 118 insertions(+), 26 deletions(-)

diff --git a/xen/drivers/passthrough/arm/smmu-v3.c 
b/xen/drivers/passthrough/arm/smmu-v3.c
index 9c9f463009..cbef3f8b36 100644
--- a/xen/drivers/passthrough/arm/smmu-v3.c
+++ b/xen/drivers/passthrough/arm/smmu-v3.c
@@ -810,6 +810,27 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device 
*smmu, u32 sid)
        return 0;
 }
 
+__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;
+}
+
 /* IRQ and event handlers */
 static void arm_smmu_evtq_tasklet(void *dev)
 {
@@ -1047,8 +1068,8 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master 
*master,
        if (!master->ats_enabled)
                return 0;
 
-       for (i = 0; i < master->num_sids; i++) {
-               cmd->atc.sid = master->sids[i];
+       for (i = 0; i < master->num_streams; i++) {
+               cmd->atc.sid = master->streams[i].id;
                arm_smmu_cmdq_issue_cmd(master->smmu, cmd);
        }
 
@@ -1276,13 +1297,13 @@ static void arm_smmu_install_ste_for_dev(struct 
arm_smmu_master *master)
        int i, j;
        struct arm_smmu_device *smmu = master->smmu;
 
-       for (i = 0; i < master->num_sids; ++i) {
-               u32 sid = master->sids[i];
+    for (i = 0; i < master->num_streams; ++i) {
+               u32 sid = master->streams[i].id;
                __le64 *step = arm_smmu_get_step_for_sid(smmu, sid);
 
                /* Bridged PCI devices may end up with duplicated IDs */
                for (j = 0; j < i; j++)
-                       if (master->sids[j] == sid)
+                       if (master->streams[j].id == sid)
                                break;
                if (j < i)
                        continue;
@@ -1489,12 +1510,86 @@ 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 *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 = _xzalloc_array(sizeof(*master->streams), sizeof(void 
*),
+                                       fwspec->num_ids);
+       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--)
+                       rb_erase(&master->streams[i].node, &smmu->streams);
+               xfree(master->streams);
+       }
+       mutex_unlock(&smmu->streams_mutex);
+
+       return ret;
+}
+
 /* Forward declaration */
 static struct arm_smmu_device *arm_smmu_get_by_dev(struct device *dev);
 
 static int arm_smmu_add_device(u8 devfn, 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);
@@ -1512,26 +1607,11 @@ static int arm_smmu_add_device(u8 devfn, struct device 
*dev)
 
        master->dev = dev;
        master->smmu = smmu;
-       master->sids = fwspec->ids;
-       master->num_sids = fwspec->num_ids;
        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;
 
        /*
         * Note that PASID must be enabled before, and disabled after ATS:
@@ -1752,6 +1832,9 @@ 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;
diff --git a/xen/drivers/passthrough/arm/smmu-v3.h 
b/xen/drivers/passthrough/arm/smmu-v3.h
index b381ad3738..b3bc7d64c7 100644
--- a/xen/drivers/passthrough/arm/smmu-v3.h
+++ b/xen/drivers/passthrough/arm/smmu-v3.h
@@ -637,6 +637,15 @@ struct arm_smmu_device {
        struct tasklet          evtq_irq_tasklet;
        struct tasklet          priq_irq_tasklet;
        struct tasklet          combined_irq_tasklet;
+
+       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 */
@@ -645,8 +654,8 @@ 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;
 };
 
-- 
2.25.1




 


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