IB/uverbs: Implement memory windows support in uverbs

The existing user/kernel uverbs API has IB_USER_VERBS_CMD_ALLOC/DEALLOC_MW.
Implement these calls, along with destroying user memory windows during
process cleanup.

Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

3 files changed, 134 insertions, 2 deletions

diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index 5bcb2afd3dcb..0fcd7aa26fa2 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -188,6 +188,8 @@ IB_UVERBS_DECLARE_CMD(alloc_pd);
 IB_UVERBS_DECLARE_CMD(dealloc_pd);
 IB_UVERBS_DECLARE_CMD(reg_mr);
 IB_UVERBS_DECLARE_CMD(dereg_mr);
+IB_UVERBS_DECLARE_CMD(alloc_mw);
+IB_UVERBS_DECLARE_CMD(dealloc_mw);
 IB_UVERBS_DECLARE_CMD(create_comp_channel);
 IB_UVERBS_DECLARE_CMD(create_cq);
 IB_UVERBS_DECLARE_CMD(resize_cq);
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 0cb0007724a2..3983a0552775 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -48,6 +48,7 @@ struct uverbs_lock_class {
 
 static struct uverbs_lock_class pd_lock_class   = { .name = "PD-uobj" };
 static struct uverbs_lock_class mr_lock_class   = { .name = "MR-uobj" };
+static struct uverbs_lock_class mw_lock_class   = { .name = "MW-uobj" };
 static struct uverbs_lock_class cq_lock_class   = { .name = "CQ-uobj" };
 static struct uverbs_lock_class qp_lock_class   = { .name = "QP-uobj" };
 static struct uverbs_lock_class ah_lock_class   = { .name = "AH-uobj" };
@@ -1049,6 +1050,126 @@ ssize_t ib_uverbs_dereg_mr(struct ib_uverbs_file *file,
         return in_len;
 }
 
+ssize_t ib_uverbs_alloc_mw(struct ib_uverbs_file *file,
+                         const char __user *buf, int in_len,
+                         int out_len)
+{
+        struct ib_uverbs_alloc_mw      cmd;
+        struct ib_uverbs_alloc_mw_resp resp;
+        struct ib_uobject             *uobj;
+        struct ib_pd                  *pd;
+        struct ib_mw                  *mw;
+        int                            ret;
+
+        if (out_len < sizeof(resp))
+                return -ENOSPC;
+
+        if (copy_from_user(&cmd, buf, sizeof(cmd)))
+                return -EFAULT;
+
+        uobj = kmalloc(sizeof(*uobj), GFP_KERNEL);
+        if (!uobj)
+                return -ENOMEM;
+
+        init_uobj(uobj, 0, file->ucontext, &mw_lock_class);
+        down_write(&uobj->mutex);
+
+        pd = idr_read_pd(cmd.pd_handle, file->ucontext);
+        if (!pd) {
+                ret = -EINVAL;
+                goto err_free;
+        }
+
+        mw = pd->device->alloc_mw(pd, cmd.mw_type);
+        if (IS_ERR(mw)) {
+                ret = PTR_ERR(mw);
+                goto err_put;
+        }
+
+        mw->device  = pd->device;
+        mw->pd      = pd;
+        mw->uobject = uobj;
+        atomic_inc(&pd->usecnt);
+
+        uobj->object = mw;
+        ret = idr_add_uobj(&ib_uverbs_mw_idr, uobj);
+        if (ret)
+                goto err_unalloc;
+
+        memset(&resp, 0, sizeof(resp));
+        resp.rkey      = mw->rkey;
+        resp.mw_handle = uobj->id;
+
+        if (copy_to_user((void __user *)(unsigned long)cmd.response,
+                         &resp, sizeof(resp))) {
+                ret = -EFAULT;
+                goto err_copy;
+        }
+
+        put_pd_read(pd);
+
+        mutex_lock(&file->mutex);
+        list_add_tail(&uobj->list, &file->ucontext->mw_list);
+        mutex_unlock(&file->mutex);
+
+        uobj->live = 1;
+
+        up_write(&uobj->mutex);
+
+        return in_len;
+
+err_copy:
+        idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
+
+err_unalloc:
+        ib_dealloc_mw(mw);
+
+err_put:
+        put_pd_read(pd);
+
+err_free:
+        put_uobj_write(uobj);
+        return ret;
+}
+
+ssize_t ib_uverbs_dealloc_mw(struct ib_uverbs_file *file,
+                           const char __user *buf, int in_len,
+                           int out_len)
+{
+        struct ib_uverbs_dealloc_mw cmd;
+        struct ib_mw               *mw;
+        struct ib_uobject          *uobj;
+        int                         ret = -EINVAL;
+
+        if (copy_from_user(&cmd, buf, sizeof(cmd)))
+                return -EFAULT;
+
+        uobj = idr_write_uobj(&ib_uverbs_mw_idr, cmd.mw_handle, file->ucontext);
+        if (!uobj)
+                return -EINVAL;
+
+        mw = uobj->object;
+
+        ret = ib_dealloc_mw(mw);
+        if (!ret)
+                uobj->live = 0;
+
+        put_uobj_write(uobj);
+
+        if (ret)
+                return ret;
+
+        idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
+
+        mutex_lock(&file->mutex);
+        list_del(&uobj->list);
+        mutex_unlock(&file->mutex);
+
+        put_uobj(uobj);
+
+        return in_len;
+}
+
 ssize_t ib_uverbs_create_comp_channel(struct ib_uverbs_file *file,
                                       const char __user *buf, int in_len,
                                       int out_len)
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 6f2ce6fa98f8..2c6f0f2ecd9d 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -87,6 +87,8 @@ static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
         [IB_USER_VERBS_CMD_DEALLOC_PD]          = ib_uverbs_dealloc_pd,
         [IB_USER_VERBS_CMD_REG_MR]              = ib_uverbs_reg_mr,
         [IB_USER_VERBS_CMD_DEREG_MR]            = ib_uverbs_dereg_mr,
+        [IB_USER_VERBS_CMD_ALLOC_MW]            = ib_uverbs_alloc_mw,
+        [IB_USER_VERBS_CMD_DEALLOC_MW]          = ib_uverbs_dealloc_mw,
         [IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
         [IB_USER_VERBS_CMD_CREATE_CQ]           = ib_uverbs_create_cq,
         [IB_USER_VERBS_CMD_RESIZE_CQ]           = ib_uverbs_resize_cq,
@@ -201,6 +203,15 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
                 kfree(uobj);
         }
 
+        /* Remove MWs before QPs, in order to support type 2A MWs. */
+        list_for_each_entry_safe(uobj, tmp, &context->mw_list, list) {
+                struct ib_mw *mw = uobj->object;
+
+                idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
+                ib_dealloc_mw(mw);
+                kfree(uobj);
+        }
+
         list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
                 struct ib_qp *qp = uobj->object;
                 struct ib_uqp_object *uqp =
@@ -240,8 +251,6 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
                 kfree(uevent);
         }
 
-        /* XXX Free MWs */
-
         list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
                 struct ib_mr *mr = uobj->object;