[PATCH] IB: Add user-supplied context to userspace CM ABI

- Add user specified context to all uCM events.  Users will not retrieve
  any events associated with the context after destroying the corresponding
  cm_id.
- Provide the ib_cm_init_qp_attr() call to userspace clients of the CM.
  This call may be used to set QP attributes properly before modifying the QP.
- Fixes some error handling synchonization and cleanup issues.
- Performs some minor code cleanup.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 192 insertions, 106 deletions

diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index 79595826ccc7..d0f0b0a2edd3 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -72,7 +72,6 @@ enum {
 
 static struct semaphore ctx_id_mutex;
 static struct idr       ctx_id_table;
-static int              ctx_id_rover = 0;
 
 static struct ib_ucm_context *ib_ucm_ctx_get(struct ib_ucm_file *file, int id)
 {
@@ -97,33 +96,16 @@ static void ib_ucm_ctx_put(struct ib_ucm_context *ctx)
                 wake_up(&ctx->wait);
 }
 
-static ssize_t ib_ucm_destroy_ctx(struct ib_ucm_file *file, int id)
+static inline int ib_ucm_new_cm_id(int event)
 {
-        struct ib_ucm_context *ctx;
-        struct ib_ucm_event *uevent;
-
-        down(&ctx_id_mutex);
-        ctx = idr_find(&ctx_id_table, id);
-        if (!ctx)
-                ctx = ERR_PTR(-ENOENT);
-        else if (ctx->file != file)
-                ctx = ERR_PTR(-EINVAL);
-        else
-                idr_remove(&ctx_id_table, ctx->id);
-        up(&ctx_id_mutex);
-
-        if (IS_ERR(ctx))
-                return PTR_ERR(ctx);
-
-        atomic_dec(&ctx->ref);
-        wait_event(ctx->wait, !atomic_read(&ctx->ref));
+        return event == IB_CM_REQ_RECEIVED || event == IB_CM_SIDR_REQ_RECEIVED;
+}
 
-        /* No new events will be generated after destroying the cm_id. */
-        if (!IS_ERR(ctx->cm_id))
-                ib_destroy_cm_id(ctx->cm_id);
+static void ib_ucm_cleanup_events(struct ib_ucm_context *ctx)
+{
+        struct ib_ucm_event *uevent;
 
-        /* Cleanup events not yet reported to the user. */
-        down(&file->mutex);
+        down(&ctx->file->mutex);
         list_del(&ctx->file_list);
         while (!list_empty(&ctx->events)) {
 
@@ -133,15 +115,12 @@ static ssize_t ib_ucm_destroy_ctx(struct ib_ucm_file *file, int id)
                 list_del(&uevent->ctx_list);
 
                 /* clear incoming connections. */
-                if (uevent->cm_id)
+                if (ib_ucm_new_cm_id(uevent->resp.event))
                         ib_destroy_cm_id(uevent->cm_id);
 
                 kfree(uevent);
         }
-        up(&file->mutex);
-
-        kfree(ctx);
-        return 0;
+        up(&ctx->file->mutex);
 }
 
 static struct ib_ucm_context *ib_ucm_ctx_alloc(struct ib_ucm_file *file)
@@ -153,36 +132,31 @@ static struct ib_ucm_context *ib_ucm_ctx_alloc(struct ib_ucm_file *file)
         if (!ctx)
                 return NULL;
 
+        memset(ctx, 0, sizeof *ctx);
         atomic_set(&ctx->ref, 1);
         init_waitqueue_head(&ctx->wait);
         ctx->file = file;
-
         INIT_LIST_HEAD(&ctx->events);
 
-        list_add_tail(&ctx->file_list, &file->ctxs);
-
-        ctx_id_rover = (ctx_id_rover + 1) & INT_MAX;
-retry:
-        result = idr_pre_get(&ctx_id_table, GFP_KERNEL);
-        if (!result)
-                goto error;
+        do {
+                result = idr_pre_get(&ctx_id_table, GFP_KERNEL);
+                if (!result)
+                        goto error;
 
-        down(&ctx_id_mutex);
-        result = idr_get_new_above(&ctx_id_table, ctx, ctx_id_rover, &ctx->id);
-        up(&ctx_id_mutex);
+                down(&ctx_id_mutex);
+                result = idr_get_new(&ctx_id_table, ctx, &ctx->id);
+                up(&ctx_id_mutex);
+        } while (result == -EAGAIN);
 
-        if (result == -EAGAIN)
-                goto retry;
         if (result)
                 goto error;
 
+        list_add_tail(&ctx->file_list, &file->ctxs);
         ucm_dbg("Allocated CM ID <%d>\n", ctx->id);
-
         return ctx;
+
 error:
-        list_del(&ctx->file_list);
         kfree(ctx);
-
         return NULL;
 }
 /*
@@ -219,12 +193,9 @@ static void ib_ucm_event_path_get(struct ib_ucm_path_rec *upath,
                 kpath->packet_life_time_selector;
 }
 
-static void ib_ucm_event_req_get(struct ib_ucm_context *ctx,
-                                 struct ib_ucm_req_event_resp *ureq,
+static void ib_ucm_event_req_get(struct ib_ucm_req_event_resp *ureq,
                                  struct ib_cm_req_event_param *kreq)
 {
-        ureq->listen_id = ctx->id;
-
         ureq->remote_ca_guid             = kreq->remote_ca_guid;
         ureq->remote_qkey                = kreq->remote_qkey;
         ureq->remote_qpn                 = kreq->remote_qpn;
@@ -259,14 +230,6 @@ static void ib_ucm_event_rep_get(struct ib_ucm_rep_event_resp *urep,
         urep->srq                 = krep->srq;
 }
 
-static void ib_ucm_event_sidr_req_get(struct ib_ucm_context *ctx,
-                                      struct ib_ucm_sidr_req_event_resp *ureq,
-                                      struct ib_cm_sidr_req_event_param *kreq)
-{
-        ureq->listen_id = ctx->id;
-        ureq->pkey      = kreq->pkey;
-}
-
 static void ib_ucm_event_sidr_rep_get(struct ib_ucm_sidr_rep_event_resp *urep,
                                       struct ib_cm_sidr_rep_event_param *krep)
 {
@@ -275,15 +238,14 @@ static void ib_ucm_event_sidr_rep_get(struct ib_ucm_sidr_rep_event_resp *urep,
         urep->qpn    = krep->qpn;
 };
 
-static int ib_ucm_event_process(struct ib_ucm_context *ctx,
-                                struct ib_cm_event *evt,
+static int ib_ucm_event_process(struct ib_cm_event *evt,
                                 struct ib_ucm_event *uvt)
 {
         void *info = NULL;
 
         switch (evt->event) {
         case IB_CM_REQ_RECEIVED:
-                ib_ucm_event_req_get(ctx, &uvt->resp.u.req_resp,
+                ib_ucm_event_req_get(&uvt->resp.u.req_resp,
                                      &evt->param.req_rcvd);
                 uvt->data_len      = IB_CM_REQ_PRIVATE_DATA_SIZE;
                 uvt->resp.present  = IB_UCM_PRES_PRIMARY;
@@ -331,8 +293,8 @@ static int ib_ucm_event_process(struct ib_ucm_context *ctx,
                 info          = evt->param.apr_rcvd.apr_info;
                 break;
         case IB_CM_SIDR_REQ_RECEIVED:
-                ib_ucm_event_sidr_req_get(ctx, &uvt->resp.u.sidr_req_resp,
-                                          &evt->param.sidr_req_rcvd);
+                uvt->resp.u.sidr_req_resp.pkey = 
+                                        evt->param.sidr_req_rcvd.pkey;
                 uvt->data_len = IB_CM_SIDR_REQ_PRIVATE_DATA_SIZE;
                 break;
         case IB_CM_SIDR_REP_RECEIVED:
@@ -378,31 +340,24 @@ static int ib_ucm_event_handler(struct ib_cm_id *cm_id,
         struct ib_ucm_event *uevent;
         struct ib_ucm_context *ctx;
         int result = 0;
-        int id;
 
         ctx = cm_id->context;
 
-        if (event->event == IB_CM_REQ_RECEIVED ||
-            event->event == IB_CM_SIDR_REQ_RECEIVED)
-                id = IB_UCM_CM_ID_INVALID;
-        else
-                id = ctx->id;
-
         uevent = kmalloc(sizeof(*uevent), GFP_KERNEL);
         if (!uevent)
                 goto err1;
 
         memset(uevent, 0, sizeof(*uevent));
-        uevent->resp.id    = id;
+        uevent->ctx = ctx;
+        uevent->cm_id = cm_id;
+        uevent->resp.uid = ctx->uid;
+        uevent->resp.id = ctx->id;
         uevent->resp.event = event->event;
 
-        result = ib_ucm_event_process(ctx, event, uevent);
+        result = ib_ucm_event_process(event, uevent);
         if (result)
                 goto err2;
 
-        uevent->ctx   = ctx;
-        uevent->cm_id = (id == IB_UCM_CM_ID_INVALID) ? cm_id : NULL;
-
         down(&ctx->file->mutex);
         list_add_tail(&uevent->file_list, &ctx->file->events);
         list_add_tail(&uevent->ctx_list, &ctx->events);
@@ -414,7 +369,7 @@ err2:
         kfree(uevent);
 err1:
         /* Destroy new cm_id's */
-        return (id == IB_UCM_CM_ID_INVALID);
+        return ib_ucm_new_cm_id(event->event);
 }
 
 static ssize_t ib_ucm_event(struct ib_ucm_file *file,
@@ -423,7 +378,7 @@ static ssize_t ib_ucm_event(struct ib_ucm_file *file,
 {
         struct ib_ucm_context *ctx;
         struct ib_ucm_event_get cmd;
-        struct ib_ucm_event *uevent = NULL;
+        struct ib_ucm_event *uevent;
         int result = 0;
         DEFINE_WAIT(wait);
 
@@ -436,7 +391,6 @@ static ssize_t ib_ucm_event(struct ib_ucm_file *file,
          * wait
          */
         down(&file->mutex);
-
         while (list_empty(&file->events)) {
 
                 if (file->filp->f_flags & O_NONBLOCK) {
@@ -463,21 +417,18 @@ static ssize_t ib_ucm_event(struct ib_ucm_file *file,
 
         uevent = list_entry(file->events.next, struct ib_ucm_event, file_list);
 
-        if (!uevent->cm_id)
-                goto user;
+        if (ib_ucm_new_cm_id(uevent->resp.event)) {
+                ctx = ib_ucm_ctx_alloc(file);
+                if (!ctx) {
+                        result = -ENOMEM;
+                        goto done;
+                }
 
-        ctx = ib_ucm_ctx_alloc(file);
-        if (!ctx) {
-                result = -ENOMEM;
-                goto done;
+                ctx->cm_id = uevent->cm_id;
+                ctx->cm_id->context = ctx;
+                uevent->resp.id = ctx->id;
         }
 
-        ctx->cm_id          = uevent->cm_id;
-        ctx->cm_id->context = ctx;
-
-        uevent->resp.id = ctx->id;
-
-user:
         if (copy_to_user((void __user *)(unsigned long)cmd.response,
                          &uevent->resp, sizeof(uevent->resp))) {
                 result = -EFAULT;
@@ -485,12 +436,10 @@ user:
         }
 
         if (uevent->data) {
-
                 if (cmd.data_len < uevent->data_len) {
                         result = -ENOMEM;
                         goto done;
                 }
-
                 if (copy_to_user((void __user *)(unsigned long)cmd.data,
                                  uevent->data, uevent->data_len)) {
                         result = -EFAULT;
@@ -499,12 +448,10 @@ user:
         }
 
         if (uevent->info) {
-
                 if (cmd.info_len < uevent->info_len) {
                         result = -ENOMEM;
                         goto done;
                 }
-
                 if (copy_to_user((void __user *)(unsigned long)cmd.info,
                                  uevent->info, uevent->info_len)) {
                         result = -EFAULT;
@@ -514,6 +461,7 @@ user:
 
         list_del(&uevent->file_list);
         list_del(&uevent->ctx_list);
+        uevent->ctx->events_reported++;
 
         kfree(uevent->data);
         kfree(uevent->info);
@@ -545,6 +493,7 @@ static ssize_t ib_ucm_create_id(struct ib_ucm_file *file,
         if (!ctx)
                 return -ENOMEM;
 
+        ctx->uid = cmd.uid;
         ctx->cm_id = ib_create_cm_id(ib_ucm_event_handler, ctx);
         if (IS_ERR(ctx->cm_id)) {
                 result = PTR_ERR(ctx->cm_id);
@@ -561,7 +510,14 @@ static ssize_t ib_ucm_create_id(struct ib_ucm_file *file,
         return 0;
 
 err:
-        ib_ucm_destroy_ctx(file, ctx->id);
+        down(&ctx_id_mutex);
+        idr_remove(&ctx_id_table, ctx->id);
+        up(&ctx_id_mutex);
+
+        if (!IS_ERR(ctx->cm_id))
+                ib_destroy_cm_id(ctx->cm_id);
+
+        kfree(ctx);
         return result;
 }
 
@@ -570,11 +526,44 @@ static ssize_t ib_ucm_destroy_id(struct ib_ucm_file *file,
                                  int in_len, int out_len)
 {
         struct ib_ucm_destroy_id cmd;
+        struct ib_ucm_destroy_id_resp resp;
+        struct ib_ucm_context *ctx;
+        int result = 0;
+
+        if (out_len < sizeof(resp))
+                return -ENOSPC;
 
         if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
                 return -EFAULT;
 
-        return ib_ucm_destroy_ctx(file, cmd.id);
+        down(&ctx_id_mutex);
+        ctx = idr_find(&ctx_id_table, cmd.id);
+        if (!ctx)
+                ctx = ERR_PTR(-ENOENT);
+        else if (ctx->file != file)
+                ctx = ERR_PTR(-EINVAL);
+        else
+                idr_remove(&ctx_id_table, ctx->id);
+        up(&ctx_id_mutex);
+
+        if (IS_ERR(ctx))
+                return PTR_ERR(ctx);
+
+        atomic_dec(&ctx->ref);
+        wait_event(ctx->wait, !atomic_read(&ctx->ref));
+
+        /* No new events will be generated after destroying the cm_id. */
+        ib_destroy_cm_id(ctx->cm_id);
+        /* Cleanup events not yet reported to the user. */
+        ib_ucm_cleanup_events(ctx);
+
+        resp.events_reported = ctx->events_reported;
+        if (copy_to_user((void __user *)(unsigned long)cmd.response,
+                         &resp, sizeof(resp)))
+                result = -EFAULT;
+
+        kfree(ctx);
+        return result;
 }
 
 static ssize_t ib_ucm_attr_id(struct ib_ucm_file *file,
@@ -609,6 +598,98 @@ static ssize_t ib_ucm_attr_id(struct ib_ucm_file *file,
         return result;
 }
 
+static void ib_ucm_copy_ah_attr(struct ib_ucm_ah_attr *dest_attr,
+                                struct ib_ah_attr *src_attr)
+{
+        memcpy(dest_attr->grh_dgid, src_attr->grh.dgid.raw,
+               sizeof src_attr->grh.dgid);
+        dest_attr->grh_flow_label = src_attr->grh.flow_label;
+        dest_attr->grh_sgid_index = src_attr->grh.sgid_index;
+        dest_attr->grh_hop_limit = src_attr->grh.hop_limit;
+        dest_attr->grh_traffic_class = src_attr->grh.traffic_class;
+
+        dest_attr->dlid = src_attr->dlid;
+        dest_attr->sl = src_attr->sl;
+        dest_attr->src_path_bits = src_attr->src_path_bits;
+        dest_attr->static_rate = src_attr->static_rate;
+        dest_attr->is_global = (src_attr->ah_flags & IB_AH_GRH);
+        dest_attr->port_num = src_attr->port_num;
+}
+
+static void ib_ucm_copy_qp_attr(struct ib_ucm_init_qp_attr_resp *dest_attr,
+                                struct ib_qp_attr *src_attr)
+{
+        dest_attr->cur_qp_state = src_attr->cur_qp_state;
+        dest_attr->path_mtu = src_attr->path_mtu;
+        dest_attr->path_mig_state = src_attr->path_mig_state;
+        dest_attr->qkey = src_attr->qkey;
+        dest_attr->rq_psn = src_attr->rq_psn;
+        dest_attr->sq_psn = src_attr->sq_psn;
+        dest_attr->dest_qp_num = src_attr->dest_qp_num;
+        dest_attr->qp_access_flags = src_attr->qp_access_flags;
+
+        dest_attr->max_send_wr = src_attr->cap.max_send_wr;
+        dest_attr->max_recv_wr = src_attr->cap.max_recv_wr;
+        dest_attr->max_send_sge = src_attr->cap.max_send_sge;
+        dest_attr->max_recv_sge = src_attr->cap.max_recv_sge;
+        dest_attr->max_inline_data = src_attr->cap.max_inline_data;
+
+        ib_ucm_copy_ah_attr(&dest_attr->ah_attr, &src_attr->ah_attr);
+        ib_ucm_copy_ah_attr(&dest_attr->alt_ah_attr, &src_attr->alt_ah_attr);
+
+        dest_attr->pkey_index = src_attr->pkey_index;
+        dest_attr->alt_pkey_index = src_attr->alt_pkey_index;
+        dest_attr->en_sqd_async_notify = src_attr->en_sqd_async_notify;
+        dest_attr->sq_draining = src_attr->sq_draining;
+        dest_attr->max_rd_atomic = src_attr->max_rd_atomic;
+        dest_attr->max_dest_rd_atomic = src_attr->max_dest_rd_atomic;
+        dest_attr->min_rnr_timer = src_attr->min_rnr_timer;
+        dest_attr->port_num = src_attr->port_num;
+        dest_attr->timeout = src_attr->timeout;
+        dest_attr->retry_cnt = src_attr->retry_cnt;
+        dest_attr->rnr_retry = src_attr->rnr_retry;
+        dest_attr->alt_port_num = src_attr->alt_port_num;
+        dest_attr->alt_timeout = src_attr->alt_timeout;
+}
+
+static ssize_t ib_ucm_init_qp_attr(struct ib_ucm_file *file,
+                                   const char __user *inbuf,
+                                   int in_len, int out_len)
+{
+        struct ib_ucm_init_qp_attr_resp resp;
+        struct ib_ucm_init_qp_attr cmd;
+        struct ib_ucm_context *ctx;
+        struct ib_qp_attr qp_attr;
+        int result = 0;
+
+        if (out_len < sizeof(resp))
+                return -ENOSPC;
+
+        if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+                return -EFAULT;
+
+        ctx = ib_ucm_ctx_get(file, cmd.id);
+        if (IS_ERR(ctx))
+                return PTR_ERR(ctx);
+
+        resp.qp_attr_mask = 0;
+        memset(&qp_attr, 0, sizeof qp_attr);
+        qp_attr.qp_state = cmd.qp_state;
+        result = ib_cm_init_qp_attr(ctx->cm_id, &qp_attr, &resp.qp_attr_mask);
+        if (result)
+                goto out;
+
+        ib_ucm_copy_qp_attr(&resp, &qp_attr);
+
+        if (copy_to_user((void __user *)(unsigned long)cmd.response,
+                         &resp, sizeof(resp)))
+                result = -EFAULT;
+
+out:
+        ib_ucm_ctx_put(ctx);
+        return result;
+}
+
 static ssize_t ib_ucm_listen(struct ib_ucm_file *file,
                              const char __user *inbuf,
                              int in_len, int out_len)
@@ -808,6 +889,7 @@ static ssize_t ib_ucm_send_rep(struct ib_ucm_file *file,
 
         ctx = ib_ucm_ctx_get(file, cmd.id);
         if (!IS_ERR(ctx)) {
+                ctx->uid = cmd.uid;
                 result = ib_send_cm_rep(ctx->cm_id, &param);
                 ib_ucm_ctx_put(ctx);
         } else
@@ -1086,6 +1168,7 @@ static ssize_t (*ucm_cmd_table[])(struct ib_ucm_file *file,
         [IB_USER_CM_CMD_SEND_SIDR_REQ] = ib_ucm_send_sidr_req,
         [IB_USER_CM_CMD_SEND_SIDR_REP] = ib_ucm_send_sidr_rep,
         [IB_USER_CM_CMD_EVENT]         = ib_ucm_event,
+        [IB_USER_CM_CMD_INIT_QP_ATTR]  = ib_ucm_init_qp_attr,
 };
 
 static ssize_t ib_ucm_write(struct file *filp, const char __user *buf,
@@ -1161,12 +1244,18 @@ static int ib_ucm_close(struct inode *inode, struct file *filp)
 
         down(&file->mutex);
         while (!list_empty(&file->ctxs)) {
-
                 ctx = list_entry(file->ctxs.next,
                                  struct ib_ucm_context, file_list);
-
                 up(&file->mutex);
-                ib_ucm_destroy_ctx(file, ctx->id);
+
+                down(&ctx_id_mutex);
+                idr_remove(&ctx_id_table, ctx->id);
+                up(&ctx_id_mutex);
+
+                ib_destroy_cm_id(ctx->cm_id);
+                ib_ucm_cleanup_events(ctx);
+                kfree(ctx);
+
                 down(&file->mutex);
         }
         up(&file->mutex);
diff --git a/drivers/infiniband/core/ucm.h b/drivers/infiniband/core/ucm.h
index c8819b928a1b..f46f37bc1201 100644
--- a/drivers/infiniband/core/ucm.h
+++ b/drivers/infiniband/core/ucm.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
+ * Copyright (c) 2005 Intel Corporation.  All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -43,8 +44,6 @@
 #include <rdma/ib_cm.h>
 #include <rdma/ib_user_cm.h>
 
-#define IB_UCM_CM_ID_INVALID 0xffffffff
-
 struct ib_ucm_file {
         struct semaphore mutex;
         struct file *filp;
@@ -58,9 +57,11 @@ struct ib_ucm_context {
         int                 id;
         wait_queue_head_t   wait;
         atomic_t            ref;
+        int                 events_reported;
 
         struct ib_ucm_file *file;
         struct ib_cm_id    *cm_id;
+        __u64              uid;
 
         struct list_head    events;    /* list of pending events. */
         struct list_head    file_list; /* member in file ctx list */
@@ -71,16 +72,12 @@ struct ib_ucm_event {
         struct list_head file_list; /* member in file event list */
         struct list_head ctx_list;  /* member in ctx event list */
 
+        struct ib_cm_id *cm_id;
         struct ib_ucm_event_resp resp;
         void *data;
         void *info;
         int data_len;
         int info_len;
-        /*
-         * new connection identifiers needs to be saved until
-         * userspace can get a handle on them.
-         */
-        struct ib_cm_id *cm_id;
 };
 
 #endif /* UCM_H */