RDMA/cma: Add multicast communication support
Extend rdma_cm to support multicast communication. Multicast support
is added to the existing RDMA_PS_UDP port space, as well as a new
RDMA_PS_IPOIB port space. The latter port space allows joining the
multicast groups used by IPoIB, which enables offloading IPoIB traffic
to a separate QP. The port space determines the signature used in the
MGID when joining the group. The newly added RDMA_PS_IPOIB also
allows for unicast operations, similar to RDMA_PS_UDP.
Supporting the RDMA_PS_IPOIB requires changing how UD QPs are initialized,
since we can no longer assume that the qkey is constant. This requires
saving the Q_Key to use when attaching to a device, so that it is
available when creating the QP. The Q_Key information is exported to
the user through the existing rdma_init_qp_attr() interface.
Multicast support is also exported to userspace through the rdma_ucm.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 6b81b98..b516b93 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -70,10 +70,24 @@
u64 uid;
struct list_head list;
+ struct list_head mc_list;
+};
+
+struct ucma_multicast {
+ struct ucma_context *ctx;
+ int id;
+ int events_reported;
+
+ u64 uid;
+ struct list_head list;
+ struct sockaddr addr;
+ u8 pad[sizeof(struct sockaddr_in6) -
+ sizeof(struct sockaddr)];
};
struct ucma_event {
struct ucma_context *ctx;
+ struct ucma_multicast *mc;
struct list_head list;
struct rdma_cm_id *cm_id;
struct rdma_ucm_event_resp resp;
@@ -81,6 +95,7 @@
static DEFINE_MUTEX(mut);
static DEFINE_IDR(ctx_idr);
+static DEFINE_IDR(multicast_idr);
static inline struct ucma_context *_ucma_find_context(int id,
struct ucma_file *file)
@@ -124,6 +139,7 @@
atomic_set(&ctx->ref, 1);
init_completion(&ctx->comp);
+ INIT_LIST_HEAD(&ctx->mc_list);
ctx->file = file;
do {
@@ -147,6 +163,37 @@
return NULL;
}
+static struct ucma_multicast* ucma_alloc_multicast(struct ucma_context *ctx)
+{
+ struct ucma_multicast *mc;
+ int ret;
+
+ mc = kzalloc(sizeof(*mc), GFP_KERNEL);
+ if (!mc)
+ return NULL;
+
+ do {
+ ret = idr_pre_get(&multicast_idr, GFP_KERNEL);
+ if (!ret)
+ goto error;
+
+ mutex_lock(&mut);
+ ret = idr_get_new(&multicast_idr, mc, &mc->id);
+ mutex_unlock(&mut);
+ } while (ret == -EAGAIN);
+
+ if (ret)
+ goto error;
+
+ mc->ctx = ctx;
+ list_add_tail(&mc->list, &ctx->mc_list);
+ return mc;
+
+error:
+ kfree(mc);
+ return NULL;
+}
+
static void ucma_copy_conn_event(struct rdma_ucm_conn_param *dst,
struct rdma_conn_param *src)
{
@@ -180,8 +227,19 @@
struct ucma_event *uevent)
{
uevent->ctx = ctx;
- uevent->resp.uid = ctx->uid;
- uevent->resp.id = ctx->id;
+ switch (event->event) {
+ case RDMA_CM_EVENT_MULTICAST_JOIN:
+ case RDMA_CM_EVENT_MULTICAST_ERROR:
+ uevent->mc = (struct ucma_multicast *)
+ event->param.ud.private_data;
+ uevent->resp.uid = uevent->mc->uid;
+ uevent->resp.id = uevent->mc->id;
+ break;
+ default:
+ uevent->resp.uid = ctx->uid;
+ uevent->resp.id = ctx->id;
+ break;
+ }
}
static int ucma_event_handler(struct rdma_cm_id *cm_id,
@@ -199,7 +257,7 @@
ucma_set_event_context(ctx, event, uevent);
uevent->resp.event = event->event;
uevent->resp.status = event->status;
- if (cm_id->ps == RDMA_PS_UDP)
+ if (cm_id->ps == RDMA_PS_UDP || cm_id->ps == RDMA_PS_IPOIB)
ucma_copy_ud_event(&uevent->resp.param.ud, &event->param.ud);
else
ucma_copy_conn_event(&uevent->resp.param.conn,
@@ -290,6 +348,8 @@
list_del(&uevent->list);
uevent->ctx->events_reported++;
+ if (uevent->mc)
+ uevent->mc->events_reported++;
kfree(uevent);
done:
mutex_unlock(&file->mut);
@@ -342,6 +402,19 @@
return ret;
}
+static void ucma_cleanup_multicast(struct ucma_context *ctx)
+{
+ struct ucma_multicast *mc, *tmp;
+
+ mutex_lock(&mut);
+ list_for_each_entry_safe(mc, tmp, &ctx->mc_list, list) {
+ list_del(&mc->list);
+ idr_remove(&multicast_idr, mc->id);
+ kfree(mc);
+ }
+ mutex_unlock(&mut);
+}
+
static void ucma_cleanup_events(struct ucma_context *ctx)
{
struct ucma_event *uevent, *tmp;
@@ -360,6 +433,19 @@
}
}
+static void ucma_cleanup_mc_events(struct ucma_multicast *mc)
+{
+ struct ucma_event *uevent, *tmp;
+
+ list_for_each_entry_safe(uevent, tmp, &mc->ctx->file->event_list, list) {
+ if (uevent->mc != mc)
+ continue;
+
+ list_del(&uevent->list);
+ kfree(uevent);
+ }
+}
+
static int ucma_free_ctx(struct ucma_context *ctx)
{
int events_reported;
@@ -367,6 +453,8 @@
/* No new events will be generated after destroying the id. */
rdma_destroy_id(ctx->cm_id);
+ ucma_cleanup_multicast(ctx);
+
/* Cleanup events not yet reported to the user. */
mutex_lock(&ctx->file->mut);
ucma_cleanup_events(ctx);
@@ -731,6 +819,114 @@
return ret;
}
+static ssize_t ucma_join_multicast(struct ucma_file *file,
+ const char __user *inbuf,
+ int in_len, int out_len)
+{
+ struct rdma_ucm_join_mcast cmd;
+ struct rdma_ucm_create_id_resp resp;
+ struct ucma_context *ctx;
+ struct ucma_multicast *mc;
+ int ret;
+
+ if (out_len < sizeof(resp))
+ return -ENOSPC;
+
+ if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+ return -EFAULT;
+
+ ctx = ucma_get_ctx(file, cmd.id);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+
+ mutex_lock(&file->mut);
+ mc = ucma_alloc_multicast(ctx);
+ if (IS_ERR(mc)) {
+ ret = PTR_ERR(mc);
+ goto err1;
+ }
+
+ mc->uid = cmd.uid;
+ memcpy(&mc->addr, &cmd.addr, sizeof cmd.addr);
+ ret = rdma_join_multicast(ctx->cm_id, &mc->addr, mc);
+ if (ret)
+ goto err2;
+
+ resp.id = mc->id;
+ if (copy_to_user((void __user *)(unsigned long)cmd.response,
+ &resp, sizeof(resp))) {
+ ret = -EFAULT;
+ goto err3;
+ }
+
+ mutex_unlock(&file->mut);
+ ucma_put_ctx(ctx);
+ return 0;
+
+err3:
+ rdma_leave_multicast(ctx->cm_id, &mc->addr);
+ ucma_cleanup_mc_events(mc);
+err2:
+ mutex_lock(&mut);
+ idr_remove(&multicast_idr, mc->id);
+ mutex_unlock(&mut);
+ list_del(&mc->list);
+ kfree(mc);
+err1:
+ mutex_unlock(&file->mut);
+ ucma_put_ctx(ctx);
+ return ret;
+}
+
+static ssize_t ucma_leave_multicast(struct ucma_file *file,
+ const char __user *inbuf,
+ int in_len, int out_len)
+{
+ struct rdma_ucm_destroy_id cmd;
+ struct rdma_ucm_destroy_id_resp resp;
+ struct ucma_multicast *mc;
+ int ret = 0;
+
+ if (out_len < sizeof(resp))
+ return -ENOSPC;
+
+ if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+ return -EFAULT;
+
+ mutex_lock(&mut);
+ mc = idr_find(&multicast_idr, cmd.id);
+ if (!mc)
+ mc = ERR_PTR(-ENOENT);
+ else if (mc->ctx->file != file)
+ mc = ERR_PTR(-EINVAL);
+ else {
+ idr_remove(&multicast_idr, mc->id);
+ atomic_inc(&mc->ctx->ref);
+ }
+ mutex_unlock(&mut);
+
+ if (IS_ERR(mc)) {
+ ret = PTR_ERR(mc);
+ goto out;
+ }
+
+ rdma_leave_multicast(mc->ctx->cm_id, &mc->addr);
+ mutex_lock(&mc->ctx->file->mut);
+ ucma_cleanup_mc_events(mc);
+ list_del(&mc->list);
+ mutex_unlock(&mc->ctx->file->mut);
+
+ ucma_put_ctx(mc->ctx);
+ resp.events_reported = mc->events_reported;
+ kfree(mc);
+
+ if (copy_to_user((void __user *)(unsigned long)cmd.response,
+ &resp, sizeof(resp)))
+ ret = -EFAULT;
+out:
+ return ret;
+}
+
static ssize_t (*ucma_cmd_table[])(struct ucma_file *file,
const char __user *inbuf,
int in_len, int out_len) = {
@@ -750,6 +946,8 @@
[RDMA_USER_CM_CMD_GET_OPTION] = NULL,
[RDMA_USER_CM_CMD_SET_OPTION] = NULL,
[RDMA_USER_CM_CMD_NOTIFY] = ucma_notify,
+ [RDMA_USER_CM_CMD_JOIN_MCAST] = ucma_join_multicast,
+ [RDMA_USER_CM_CMD_LEAVE_MCAST] = ucma_leave_multicast,
};
static ssize_t ucma_write(struct file *filp, const char __user *buf,