clients/rdsv3/rdma.c

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * This file contains code imported from the OFED rds source file rdma.c
 * Oracle elects to have and use the contents of rdma.c under and governed
 * by the OpenIB.org BSD license (see below for full license text). However,
 * the following notice accompanied the original version of this file:
 */

/*
 * Copyright (c) 2007 Oracle.  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
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <sys/ib/clients/of/rdma/ib_verbs.h>
#include <sys/ib/clients/of/rdma/ib_addr.h>
#include <sys/ib/clients/of/rdma/rdma_cm.h>

#include <sys/ib/clients/rdsv3/ib.h>
#include <sys/ib/clients/rdsv3/rdma.h>
#include <sys/ib/clients/rdsv3/rdsv3_debug.h>

#define DMA_TO_DEVICE 0
#define DMA_FROM_DEVICE 1
#define RB_CLEAR_NODE(nodep) AVL_SETPARENT(nodep, nodep);

/*
 * XXX
 *  - build with sparse
 *  - should we limit the size of a mr region?  let transport return failure?
 *  - should we detect duplicate keys on a socket?  hmm.
 *  - an rdma is an mlock, apply rlimit?
 */

/*
 * get the number of pages by looking at the page indices that the start and
 * end addresses fall in.
 *
 * Returns 0 if the vec is invalid.  It is invalid if the number of bytes
 * causes the address to wrap or overflows an unsigned int.  This comes
 * from being stored in the 'length' member of 'struct rdsv3_scatterlist'.
 */
static unsigned int
rdsv3_pages_in_vec(struct rds_iovec *vec)
{
    if ((vec->addr + vec->bytes <= vec->addr) ||
        (vec->bytes > (uint64_t)UINT_MAX)) {
        return (0);
    }

    return (((vec->addr + vec->bytes + PAGESIZE - 1) >>
        PAGESHIFT) - (vec->addr >> PAGESHIFT));
}

static struct rdsv3_mr *
rdsv3_mr_tree_walk(struct avl_tree *root, uint32_t key,
    struct rdsv3_mr *insert)
{
    struct rdsv3_mr *mr;
    avl_index_t where;

    mr = avl_find(root, &key, &where);
    if ((mr == NULL) && (insert != NULL)) {
        avl_insert(root, (void *)insert, where);
        atomic_inc_32(&insert->r_refcount);
        return (NULL);
    }

    return (mr);
}

/*
 * Destroy the transport-specific part of a MR.
 */
static void
rdsv3_destroy_mr(struct rdsv3_mr *mr)
{
    struct rdsv3_sock *rs = mr->r_sock;
    void *trans_private = NULL;
    avl_node_t *np;

    RDSV3_DPRINTF5("rdsv3_destroy_mr",
        "RDS: destroy mr key is %x refcnt %u",
        mr->r_key, atomic_get(&mr->r_refcount));

    if (test_and_set_bit(RDSV3_MR_DEAD, &mr->r_state))
        return;

    mutex_enter(&rs->rs_rdma_lock);
    np = &mr->r_rb_node;
    if (AVL_XPARENT(np) != np)
        avl_remove(&rs->rs_rdma_keys, mr);
    trans_private = mr->r_trans_private;
    mr->r_trans_private = NULL;
    mutex_exit(&rs->rs_rdma_lock);

    if (trans_private)
        mr->r_trans->free_mr(trans_private, mr->r_invalidate);
}

void
__rdsv3_put_mr_final(struct rdsv3_mr *mr)
{
    rdsv3_destroy_mr(mr);
    kmem_free(mr, sizeof (*mr));
}

/*
 * By the time this is called we can't have any more ioctls called on
 * the socket so we don't need to worry about racing with others.
 */
void
rdsv3_rdma_drop_keys(struct rdsv3_sock *rs)
{
    struct rdsv3_mr *mr;
    struct avl_node *node;

    /* Release any MRs associated with this socket */
    mutex_enter(&rs->rs_rdma_lock);
    while ((node = avl_first(&rs->rs_rdma_keys))) {
        mr = container_of(node, struct rdsv3_mr, r_rb_node);
        if (mr->r_trans == rs->rs_transport)
            mr->r_invalidate = 0;
        avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
        RB_CLEAR_NODE(&mr->r_rb_node)
        mutex_exit(&rs->rs_rdma_lock);
        rdsv3_destroy_mr(mr);
        rdsv3_mr_put(mr);
        mutex_enter(&rs->rs_rdma_lock);
    }
    mutex_exit(&rs->rs_rdma_lock);

    if (rs->rs_transport && rs->rs_transport->flush_mrs)
        rs->rs_transport->flush_mrs();
}

static int
__rdsv3_rdma_map(struct rdsv3_sock *rs, struct rds_get_mr_args *args,
    uint64_t *cookie_ret, struct rdsv3_mr **mr_ret)
{
    struct rdsv3_mr *mr = NULL, *found;
    void *trans_private;
    rds_rdma_cookie_t cookie;
    unsigned int nents = 0;
    int ret;

    if (rs->rs_bound_addr == 0) {
        ret = -ENOTCONN; /* XXX not a great errno */
        goto out;
    }

    if (!rs->rs_transport->get_mr) {
        ret = -EOPNOTSUPP;
        goto out;
    }

    mr = kmem_zalloc(sizeof (struct rdsv3_mr), KM_NOSLEEP);
    if (!mr) {
        ret = -ENOMEM;
        goto out;
    }

    mr->r_refcount = 1;
    RB_CLEAR_NODE(&mr->r_rb_node);
    mr->r_trans = rs->rs_transport;
    mr->r_sock = rs;

    if (args->flags & RDS_RDMA_USE_ONCE)
        mr->r_use_once = 1;
    if (args->flags & RDS_RDMA_INVALIDATE)
        mr->r_invalidate = 1;
    if (args->flags & RDS_RDMA_READWRITE)
        mr->r_write = 1;

    /*
     * Obtain a transport specific MR. If this succeeds, the
     * s/g list is now owned by the MR.
     * Note that dma_map() implies that pending writes are
     * flushed to RAM, so no dma_sync is needed here.
     */
    trans_private = rs->rs_transport->get_mr(&args->vec, nents, rs,
        &mr->r_key);

    if (IS_ERR(trans_private)) {
        ret = PTR_ERR(trans_private);
        goto out;
    }

    mr->r_trans_private = trans_private;

    /*
     * The user may pass us an unaligned address, but we can only
     * map page aligned regions. So we keep the offset, and build
     * a 64bit cookie containing <R_Key, offset> and pass that
     * around.
     */
    cookie = rdsv3_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGEMASK);
    if (cookie_ret)
        *cookie_ret = cookie;

    /*
     * copy value of cookie to user address at args->cookie_addr
     */
    if (args->cookie_addr) {
        ret = ddi_copyout((void *)&cookie,
            (void *)((intptr_t)args->cookie_addr),
            sizeof (rds_rdma_cookie_t), 0);
        if (ret != 0) {
            ret = -EFAULT;
            goto out;
        }
    }

    RDSV3_DPRINTF5("__rdsv3_rdma_map",
        "RDS: get_mr mr 0x%p addr 0x%llx key 0x%x",
        mr, args->vec.addr, mr->r_key);
    /*
     * Inserting the new MR into the rbtree bumps its
     * reference count.
     */
    mutex_enter(&rs->rs_rdma_lock);
    found = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
    mutex_exit(&rs->rs_rdma_lock);

    ASSERT(!(found && found != mr));

    if (mr_ret) {
        atomic_inc_32(&mr->r_refcount);
        *mr_ret = mr;
    }

    ret = 0;
out:
    if (mr)
        rdsv3_mr_put(mr);
    return (ret);
}

int
rdsv3_get_mr(struct rdsv3_sock *rs, const void *optval, int optlen)
{
    struct rds_get_mr_args args;

    if (optlen != sizeof (struct rds_get_mr_args))
        return (-EINVAL);

#if 1
    bcopy((struct rds_get_mr_args *)optval, &args,
        sizeof (struct rds_get_mr_args));
#else
    if (ddi_copyin(optval, &args, optlen, 0))
        return (-EFAULT);
#endif

    return (__rdsv3_rdma_map(rs, &args, NULL, NULL));
}

int
rdsv3_get_mr_for_dest(struct rdsv3_sock *rs, const void *optval,
    int optlen)
{
    struct rds_get_mr_for_dest_args args;
    struct rds_get_mr_args new_args;

    if (optlen != sizeof (struct rds_get_mr_for_dest_args))
        return (-EINVAL);

#if 1
    bcopy((struct rds_get_mr_for_dest_args *)optval, &args,
        sizeof (struct rds_get_mr_for_dest_args));
#else
    if (ddi_copyin(optval, &args, optlen, 0))
        return (-EFAULT);
#endif

    /*
     * Initially, just behave like get_mr().
     * TODO: Implement get_mr as wrapper around this
     *   and deprecate it.
     */
    new_args.vec = args.vec;
    new_args.cookie_addr = args.cookie_addr;
    new_args.flags = args.flags;

    return (__rdsv3_rdma_map(rs, &new_args, NULL, NULL));
}

/*
 * Free the MR indicated by the given R_Key
 */
int
rdsv3_free_mr(struct rdsv3_sock *rs, const void *optval, int optlen)
{
    struct rds_free_mr_args args;
    struct rdsv3_mr *mr;

    if (optlen != sizeof (struct rds_free_mr_args))
        return (-EINVAL);

#if 1
    bcopy((struct rds_free_mr_args *)optval, &args,
        sizeof (struct rds_free_mr_args));
#else
    if (ddi_copyin((struct rds_free_mr_args *)optval, &args,
        sizeof (struct rds_free_mr_args), 0))
        return (-EFAULT);
#endif

    /* Special case - a null cookie means flush all unused MRs */
    if (args.cookie == 0) {
        if (!rs->rs_transport || !rs->rs_transport->flush_mrs)
            return (-EINVAL);
        rs->rs_transport->flush_mrs();
        return (0);
    }

    /*
     * Look up the MR given its R_key and remove it from the rbtree
     * so nobody else finds it.
     * This should also prevent races with rdsv3_rdma_unuse.
     */
    mutex_enter(&rs->rs_rdma_lock);
    mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys,
        rdsv3_rdma_cookie_key(args.cookie), NULL);
    if (mr) {
        avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
        RB_CLEAR_NODE(&mr->r_rb_node);
        if (args.flags & RDS_RDMA_INVALIDATE)
            mr->r_invalidate = 1;
    }
    mutex_exit(&rs->rs_rdma_lock);

    if (!mr)
        return (-EINVAL);

    /*
     * call rdsv3_destroy_mr() ourselves so that we're sure it's done
     * by time we return.  If we let rdsv3_mr_put() do it it might not
     * happen until someone else drops their ref.
     */
    rdsv3_destroy_mr(mr);
    rdsv3_mr_put(mr);
    return (0);
}

/*
 * This is called when we receive an extension header that
 * tells us this MR was used. It allows us to implement
 * use_once semantics
 */
void
rdsv3_rdma_unuse(struct rdsv3_sock *rs, uint32_t r_key, int force)
{
    struct rdsv3_mr *mr;
    int zot_me = 0;

    RDSV3_DPRINTF4("rdsv3_rdma_unuse", "Enter rkey: 0x%x", r_key);

    mutex_enter(&rs->rs_rdma_lock);
    mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
    if (!mr) {
        RDSV3_DPRINTF4("rdsv3_rdma_unuse",
            "rdsv3: trying to unuse MR with unknown r_key %u!", r_key);
        mutex_exit(&rs->rs_rdma_lock);
        return;
    }

    if (mr->r_use_once || force) {
        avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
        RB_CLEAR_NODE(&mr->r_rb_node);
        zot_me = 1;
    } else {
        atomic_inc_32(&mr->r_refcount);
    }
    mutex_exit(&rs->rs_rdma_lock);

    /*
     * May have to issue a dma_sync on this memory region.
     * Note we could avoid this if the operation was a RDMA READ,
     * but at this point we can't tell.
     */
    if (mr->r_trans->sync_mr)
        mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);

    /*
     * If the MR was marked as invalidate, this will
     * trigger an async flush.
     */
    if (zot_me)
        rdsv3_destroy_mr(mr);
    rdsv3_mr_put(mr);
    RDSV3_DPRINTF4("rdsv3_rdma_unuse", "Return");
}

void
rdsv3_rdma_free_op(struct rdsv3_rdma_op *ro)
{
    unsigned int i;

    /* deallocate RDMA resources on rdsv3_message */
    for (i = 0; i < ro->r_nents; i++) {
        ddi_umem_unlock(ro->r_rdma_sg[i].umem_cookie);
    }

    if (ro->r_notifier)
        kmem_free(ro->r_notifier, sizeof (*ro->r_notifier));
    kmem_free(ro, sizeof (*ro));
}

/*
 * args is a pointer to an in-kernel copy in the sendmsg cmsg.
 */
static struct rdsv3_rdma_op *
rdsv3_rdma_prepare(struct rdsv3_sock *rs, struct rds_rdma_args *args)
{
    struct rds_iovec vec;
    struct rdsv3_rdma_op *op = NULL;
    unsigned int nr_bytes;
    struct rds_iovec *local_vec;
    unsigned int nr;
    unsigned int i;
    ddi_umem_cookie_t umem_cookie;
    size_t umem_len;
    caddr_t umem_addr;
    int ret;

    if (rs->rs_bound_addr == 0) {
        ret = -ENOTCONN; /* XXX not a great errno */
        goto out;
    }

    if (args->nr_local > (uint64_t)UINT_MAX) {
        ret = -EMSGSIZE;
        goto out;
    }

    op = kmem_zalloc(offsetof(struct rdsv3_rdma_op,
        r_rdma_sg[args->nr_local]), KM_NOSLEEP);
    if (op == NULL) {
        ret = -ENOMEM;
        goto out;
    }

    op->r_write = !!(args->flags & RDS_RDMA_READWRITE);
    op->r_fence = !!(args->flags & RDS_RDMA_FENCE);
    op->r_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
    op->r_recverr = rs->rs_recverr;

    if (op->r_notify || op->r_recverr) {
        /*
         * We allocate an uninitialized notifier here, because
         * we don't want to do that in the completion handler. We
         * would have to use GFP_ATOMIC there, and don't want to deal
         * with failed allocations.
         */
        op->r_notifier = kmem_alloc(sizeof (struct rdsv3_notifier),
            KM_NOSLEEP);
        if (!op->r_notifier) {
            ret = -ENOMEM;
            goto out;
        }
        op->r_notifier->n_user_token = args->user_token;
        op->r_notifier->n_status = RDS_RDMA_SUCCESS;
    }

    /*
     * The cookie contains the R_Key of the remote memory region, and
     * optionally an offset into it. This is how we implement RDMA into
     * unaligned memory.
     * When setting up the RDMA, we need to add that offset to the
     * destination address (which is really an offset into the MR)
     * FIXME: We may want to move this into ib_rdma.c
     */
    op->r_key = rdsv3_rdma_cookie_key(args->cookie);
    op->r_remote_addr = args->remote_vec.addr +
        rdsv3_rdma_cookie_offset(args->cookie);

    nr_bytes = 0;

    RDSV3_DPRINTF5("rdsv3_rdma_prepare",
        "RDS: rdma prepare nr_local %llu rva %llx rkey %x",
        (unsigned long long)args->nr_local,
        (unsigned long long)args->remote_vec.addr,
        op->r_key);

    local_vec = (struct rds_iovec *)(unsigned long) args->local_vec_addr;

    /* pin the scatter list of user buffers */
    for (i = 0; i < args->nr_local; i++) {
        if (ddi_copyin(&local_vec[i], &vec,
            sizeof (struct rds_iovec), 0)) {
            ret = -EFAULT;
            goto out;
        }

        nr = rdsv3_pages_in_vec(&vec);
        if (nr == 0) {
            RDSV3_DPRINTF2("rdsv3_rdma_prepare",
                "rdsv3_pages_in_vec returned 0");
            ret = -EINVAL;
            goto out;
        }

        rs->rs_user_addr = vec.addr;
        rs->rs_user_bytes = vec.bytes;

        /* pin user memory pages */
        umem_len = ptob(btopr(vec.bytes +
            ((uintptr_t)vec.addr & PAGEOFFSET)));
        umem_addr = (caddr_t)((uintptr_t)vec.addr & ~PAGEOFFSET);
        ret = umem_lockmemory(umem_addr, umem_len,
            DDI_UMEMLOCK_WRITE | DDI_UMEMLOCK_READ,
            &umem_cookie, NULL, NULL);
        if (ret != 0) {
            RDSV3_DPRINTF2("rdsv3_rdma_prepare",
                "umem_lockmemory() returned %d", ret);
            ret = -EFAULT;
            goto out;
        }
        op->r_rdma_sg[i].umem_cookie = umem_cookie;
        op->r_rdma_sg[i].iovec = vec;
        nr_bytes += vec.bytes;

        RDSV3_DPRINTF5("rdsv3_rdma_prepare",
            "RDS: nr_bytes %u nr %u vec.bytes %llu vec.addr %llx",
            nr_bytes, nr, vec.bytes, vec.addr);
    }
    op->r_nents = i;

    if (nr_bytes > args->remote_vec.bytes) {
        RDSV3_DPRINTF2("rdsv3_rdma_prepare",
            "RDS nr_bytes %u remote_bytes %u do not match",
            nr_bytes, (unsigned int) args->remote_vec.bytes);
        ret = -EINVAL;
        goto out;
    }
    op->r_bytes = nr_bytes;

    ret = 0;
out:
    if (ret) {
        if (op)
            rdsv3_rdma_free_op(op);
        op = ERR_PTR(ret);
    }
    return (op);
}

#define CEIL(x, y)  (((x) + (y) - 1) / (y))

/*
 * The application asks for a RDMA transfer.
 * Extract all arguments and set up the rdma_op
 */
int
rdsv3_cmsg_rdma_args(struct rdsv3_sock *rs, struct rdsv3_message *rm,
    struct cmsghdr *cmsg)
{
    struct rdsv3_rdma_op *op;
    /* uint64_t alignment on the buffer */
    uint64_t buf[CEIL(CMSG_LEN(sizeof (struct rds_rdma_args)),
        sizeof (uint64_t))];

    if (cmsg->cmsg_len != CMSG_LEN(sizeof (struct rds_rdma_args)) ||
        rm->m_rdma_op != NULL)
        return (-EINVAL);

    ASSERT(sizeof (buf) >= cmsg->cmsg_len && ((uintptr_t)buf & 0x7) == 0);

    bcopy(CMSG_DATA(cmsg), (char *)buf, cmsg->cmsg_len);
    op = rdsv3_rdma_prepare(rs, (struct rds_rdma_args *)buf);

    if (IS_ERR(op))
        return (PTR_ERR(op));
    rdsv3_stats_inc(s_send_rdma);
    rm->m_rdma_op = op;
    return (0);
}

/*
 * The application wants us to pass an RDMA destination (aka MR)
 * to the remote
 */
int
rdsv3_cmsg_rdma_dest(struct rdsv3_sock *rs, struct rdsv3_message *rm,
    struct cmsghdr *cmsg)
{
    struct rdsv3_mr *mr;
    uint32_t r_key;
    int err = 0;

    if (cmsg->cmsg_len != CMSG_LEN(sizeof (rds_rdma_cookie_t)) ||
        rm->m_rdma_cookie != 0)
        return (-EINVAL);

    (void) memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg),
        sizeof (rm->m_rdma_cookie));

    /*
     * We are reusing a previously mapped MR here. Most likely, the
     * application has written to the buffer, so we need to explicitly
     * flush those writes to RAM. Otherwise the HCA may not see them
     * when doing a DMA from that buffer.
     */
    r_key = rdsv3_rdma_cookie_key(rm->m_rdma_cookie);

    mutex_enter(&rs->rs_rdma_lock);
    mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
    if (!mr)
        err = -EINVAL;  /* invalid r_key */
    else
        atomic_inc_32(&mr->r_refcount);
    mutex_exit(&rs->rs_rdma_lock);

    if (mr) {
        mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE);
        rm->m_rdma_mr = mr;
    }
    return (err);
}

/*
 * The application passes us an address range it wants to enable RDMA
 * to/from. We map the area, and save the <R_Key,offset> pair
 * in rm->m_rdma_cookie. This causes it to be sent along to the peer
 * in an extension header.
 */
int
rdsv3_cmsg_rdma_map(struct rdsv3_sock *rs, struct rdsv3_message *rm,
    struct cmsghdr *cmsg)
{
    /* uint64_t alignment on the buffer */
    uint64_t buf[CEIL(CMSG_LEN(sizeof (struct rds_get_mr_args)),
        sizeof (uint64_t))];
    int status;

    if (cmsg->cmsg_len != CMSG_LEN(sizeof (struct rds_get_mr_args)) ||
        rm->m_rdma_cookie != 0)
        return (-EINVAL);

    ASSERT(sizeof (buf) >= cmsg->cmsg_len && ((uintptr_t)buf & 0x7) == 0);

    bcopy(CMSG_DATA(cmsg), (char *)buf, cmsg->cmsg_len);
    status = __rdsv3_rdma_map(rs, (struct rds_get_mr_args *)buf,
        &rm->m_rdma_cookie, &rm->m_rdma_mr);

    return (status);
}