summaryrefslogtreecommitdiffstats
path: root/net/rds/rdma.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/rds/rdma.c')
-rw-r--r--net/rds/rdma.c891
1 files changed, 891 insertions, 0 deletions
diff --git a/net/rds/rdma.c b/net/rds/rdma.c
new file mode 100644
index 000000000..9882cebfc
--- /dev/null
+++ b/net/rds/rdma.c
@@ -0,0 +1,891 @@
+/*
+ * Copyright (c) 2007, 2017 Oracle and/or its affiliates. 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 <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/rbtree.h>
+#include <linux/dma-mapping.h> /* for DMA_*_DEVICE */
+
+#include "rds.h"
+
+/*
+ * XXX
+ * - build with sparse
+ * - 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 scatterlist'.
+ */
+static unsigned int rds_pages_in_vec(struct rds_iovec *vec)
+{
+ if ((vec->addr + vec->bytes <= vec->addr) ||
+ (vec->bytes > (u64)UINT_MAX))
+ return 0;
+
+ return ((vec->addr + vec->bytes + PAGE_SIZE - 1) >> PAGE_SHIFT) -
+ (vec->addr >> PAGE_SHIFT);
+}
+
+static struct rds_mr *rds_mr_tree_walk(struct rb_root *root, u64 key,
+ struct rds_mr *insert)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct rds_mr *mr;
+
+ while (*p) {
+ parent = *p;
+ mr = rb_entry(parent, struct rds_mr, r_rb_node);
+
+ if (key < mr->r_key)
+ p = &(*p)->rb_left;
+ else if (key > mr->r_key)
+ p = &(*p)->rb_right;
+ else
+ return mr;
+ }
+
+ if (insert) {
+ rb_link_node(&insert->r_rb_node, parent, p);
+ rb_insert_color(&insert->r_rb_node, root);
+ refcount_inc(&insert->r_refcount);
+ }
+ return NULL;
+}
+
+/*
+ * Destroy the transport-specific part of a MR.
+ */
+static void rds_destroy_mr(struct rds_mr *mr)
+{
+ struct rds_sock *rs = mr->r_sock;
+ void *trans_private = NULL;
+ unsigned long flags;
+
+ rdsdebug("RDS: destroy mr key is %x refcnt %u\n",
+ mr->r_key, refcount_read(&mr->r_refcount));
+
+ if (test_and_set_bit(RDS_MR_DEAD, &mr->r_state))
+ return;
+
+ spin_lock_irqsave(&rs->rs_rdma_lock, flags);
+ if (!RB_EMPTY_NODE(&mr->r_rb_node))
+ rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
+ trans_private = mr->r_trans_private;
+ mr->r_trans_private = NULL;
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+
+ if (trans_private)
+ mr->r_trans->free_mr(trans_private, mr->r_invalidate);
+}
+
+void __rds_put_mr_final(struct rds_mr *mr)
+{
+ rds_destroy_mr(mr);
+ kfree(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 rds_rdma_drop_keys(struct rds_sock *rs)
+{
+ struct rds_mr *mr;
+ struct rb_node *node;
+ unsigned long flags;
+
+ /* Release any MRs associated with this socket */
+ spin_lock_irqsave(&rs->rs_rdma_lock, flags);
+ while ((node = rb_first(&rs->rs_rdma_keys))) {
+ mr = rb_entry(node, struct rds_mr, r_rb_node);
+ if (mr->r_trans == rs->rs_transport)
+ mr->r_invalidate = 0;
+ rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
+ RB_CLEAR_NODE(&mr->r_rb_node);
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+ rds_destroy_mr(mr);
+ rds_mr_put(mr);
+ spin_lock_irqsave(&rs->rs_rdma_lock, flags);
+ }
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+
+ if (rs->rs_transport && rs->rs_transport->flush_mrs)
+ rs->rs_transport->flush_mrs();
+}
+
+/*
+ * Helper function to pin user pages.
+ */
+static int rds_pin_pages(unsigned long user_addr, unsigned int nr_pages,
+ struct page **pages, int write)
+{
+ int ret;
+
+ ret = get_user_pages_fast(user_addr, nr_pages, write, pages);
+
+ if (ret >= 0 && ret < nr_pages) {
+ while (ret--)
+ put_page(pages[ret]);
+ ret = -EFAULT;
+ }
+
+ return ret;
+}
+
+static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args,
+ u64 *cookie_ret, struct rds_mr **mr_ret,
+ struct rds_conn_path *cp)
+{
+ struct rds_mr *mr = NULL, *found;
+ unsigned int nr_pages;
+ struct page **pages = NULL;
+ struct scatterlist *sg;
+ void *trans_private;
+ unsigned long flags;
+ rds_rdma_cookie_t cookie;
+ unsigned int nents;
+ long i;
+ int ret;
+
+ if (ipv6_addr_any(&rs->rs_bound_addr) || !rs->rs_transport) {
+ ret = -ENOTCONN; /* XXX not a great errno */
+ goto out;
+ }
+
+ if (!rs->rs_transport->get_mr) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ nr_pages = rds_pages_in_vec(&args->vec);
+ if (nr_pages == 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Restrict the size of mr irrespective of underlying transport
+ * To account for unaligned mr regions, subtract one from nr_pages
+ */
+ if ((nr_pages - 1) > (RDS_MAX_MSG_SIZE >> PAGE_SHIFT)) {
+ ret = -EMSGSIZE;
+ goto out;
+ }
+
+ rdsdebug("RDS: get_mr addr %llx len %llu nr_pages %u\n",
+ args->vec.addr, args->vec.bytes, nr_pages);
+
+ /* XXX clamp nr_pages to limit the size of this alloc? */
+ pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!pages) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ mr = kzalloc(sizeof(struct rds_mr), GFP_KERNEL);
+ if (!mr) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ refcount_set(&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;
+
+ /*
+ * Pin the pages that make up the user buffer and transfer the page
+ * pointers to the mr's sg array. We check to see if we've mapped
+ * the whole region after transferring the partial page references
+ * to the sg array so that we can have one page ref cleanup path.
+ *
+ * For now we have no flag that tells us whether the mapping is
+ * r/o or r/w. We need to assume r/w, or we'll do a lot of RDMA to
+ * the zero page.
+ */
+ ret = rds_pin_pages(args->vec.addr, nr_pages, pages, 1);
+ if (ret < 0)
+ goto out;
+
+ nents = ret;
+ sg = kcalloc(nents, sizeof(*sg), GFP_KERNEL);
+ if (!sg) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ WARN_ON(!nents);
+ sg_init_table(sg, nents);
+
+ /* Stick all pages into the scatterlist */
+ for (i = 0 ; i < nents; i++)
+ sg_set_page(&sg[i], pages[i], PAGE_SIZE, 0);
+
+ rdsdebug("RDS: trans_private nents is %u\n", nents);
+
+ /* 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(sg, nents, rs,
+ &mr->r_key,
+ cp ? cp->cp_conn : NULL);
+
+ if (IS_ERR(trans_private)) {
+ for (i = 0 ; i < nents; i++)
+ put_page(sg_page(&sg[i]));
+ kfree(sg);
+ ret = PTR_ERR(trans_private);
+ goto out;
+ }
+
+ mr->r_trans_private = trans_private;
+
+ rdsdebug("RDS: get_mr put_user key is %x cookie_addr %p\n",
+ mr->r_key, (void *)(unsigned long) args->cookie_addr);
+
+ /* 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 = rds_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGE_MASK);
+ if (cookie_ret)
+ *cookie_ret = cookie;
+
+ if (args->cookie_addr && put_user(cookie, (u64 __user *)(unsigned long) args->cookie_addr)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ /* Inserting the new MR into the rbtree bumps its
+ * reference count. */
+ spin_lock_irqsave(&rs->rs_rdma_lock, flags);
+ found = rds_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+
+ BUG_ON(found && found != mr);
+
+ rdsdebug("RDS: get_mr key is %x\n", mr->r_key);
+ if (mr_ret) {
+ refcount_inc(&mr->r_refcount);
+ *mr_ret = mr;
+ }
+
+ ret = 0;
+out:
+ kfree(pages);
+ if (mr)
+ rds_mr_put(mr);
+ return ret;
+}
+
+int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen)
+{
+ struct rds_get_mr_args args;
+
+ if (optlen != sizeof(struct rds_get_mr_args))
+ return -EINVAL;
+
+ if (copy_from_user(&args, (struct rds_get_mr_args __user *)optval,
+ sizeof(struct rds_get_mr_args)))
+ return -EFAULT;
+
+ return __rds_rdma_map(rs, &args, NULL, NULL, NULL);
+}
+
+int rds_get_mr_for_dest(struct rds_sock *rs, char __user *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 (copy_from_user(&args, (struct rds_get_mr_for_dest_args __user *)optval,
+ sizeof(struct rds_get_mr_for_dest_args)))
+ return -EFAULT;
+
+ /*
+ * 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 __rds_rdma_map(rs, &new_args, NULL, NULL, NULL);
+}
+
+/*
+ * Free the MR indicated by the given R_Key
+ */
+int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen)
+{
+ struct rds_free_mr_args args;
+ struct rds_mr *mr;
+ unsigned long flags;
+
+ if (optlen != sizeof(struct rds_free_mr_args))
+ return -EINVAL;
+
+ if (copy_from_user(&args, (struct rds_free_mr_args __user *)optval,
+ sizeof(struct rds_free_mr_args)))
+ return -EFAULT;
+
+ /* 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 rds_rdma_unuse.
+ */
+ spin_lock_irqsave(&rs->rs_rdma_lock, flags);
+ mr = rds_mr_tree_walk(&rs->rs_rdma_keys, rds_rdma_cookie_key(args.cookie), NULL);
+ if (mr) {
+ rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
+ RB_CLEAR_NODE(&mr->r_rb_node);
+ if (args.flags & RDS_RDMA_INVALIDATE)
+ mr->r_invalidate = 1;
+ }
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+
+ if (!mr)
+ return -EINVAL;
+
+ /*
+ * call rds_destroy_mr() ourselves so that we're sure it's done by the time
+ * we return. If we let rds_mr_put() do it it might not happen until
+ * someone else drops their ref.
+ */
+ rds_destroy_mr(mr);
+ rds_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 rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force)
+{
+ struct rds_mr *mr;
+ unsigned long flags;
+ int zot_me = 0;
+
+ spin_lock_irqsave(&rs->rs_rdma_lock, flags);
+ mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
+ if (!mr) {
+ pr_debug("rds: trying to unuse MR with unknown r_key %u!\n",
+ r_key);
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+ return;
+ }
+
+ if (mr->r_use_once || force) {
+ rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
+ RB_CLEAR_NODE(&mr->r_rb_node);
+ zot_me = 1;
+ }
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+
+ /* 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) {
+ rds_destroy_mr(mr);
+ rds_mr_put(mr);
+ }
+}
+
+void rds_rdma_free_op(struct rm_rdma_op *ro)
+{
+ unsigned int i;
+
+ for (i = 0; i < ro->op_nents; i++) {
+ struct page *page = sg_page(&ro->op_sg[i]);
+
+ /* Mark page dirty if it was possibly modified, which
+ * is the case for a RDMA_READ which copies from remote
+ * to local memory */
+ if (!ro->op_write) {
+ WARN_ON(!page->mapping && irqs_disabled());
+ set_page_dirty(page);
+ }
+ put_page(page);
+ }
+
+ kfree(ro->op_notifier);
+ ro->op_notifier = NULL;
+ ro->op_active = 0;
+}
+
+void rds_atomic_free_op(struct rm_atomic_op *ao)
+{
+ struct page *page = sg_page(ao->op_sg);
+
+ /* Mark page dirty if it was possibly modified, which
+ * is the case for a RDMA_READ which copies from remote
+ * to local memory */
+ set_page_dirty(page);
+ put_page(page);
+
+ kfree(ao->op_notifier);
+ ao->op_notifier = NULL;
+ ao->op_active = 0;
+}
+
+
+/*
+ * Count the number of pages needed to describe an incoming iovec array.
+ */
+static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs)
+{
+ int tot_pages = 0;
+ unsigned int nr_pages;
+ unsigned int i;
+
+ /* figure out the number of pages in the vector */
+ for (i = 0; i < nr_iovecs; i++) {
+ nr_pages = rds_pages_in_vec(&iov[i]);
+ if (nr_pages == 0)
+ return -EINVAL;
+
+ tot_pages += nr_pages;
+
+ /*
+ * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
+ * so tot_pages cannot overflow without first going negative.
+ */
+ if (tot_pages < 0)
+ return -EINVAL;
+ }
+
+ return tot_pages;
+}
+
+int rds_rdma_extra_size(struct rds_rdma_args *args,
+ struct rds_iov_vector *iov)
+{
+ struct rds_iovec *vec;
+ struct rds_iovec __user *local_vec;
+ int tot_pages = 0;
+ unsigned int nr_pages;
+ unsigned int i;
+
+ local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
+
+ if (args->nr_local == 0)
+ return -EINVAL;
+
+ if (args->nr_local > UIO_MAXIOV)
+ return -EMSGSIZE;
+
+ iov->iov = kcalloc(args->nr_local,
+ sizeof(struct rds_iovec),
+ GFP_KERNEL);
+ if (!iov->iov)
+ return -ENOMEM;
+
+ vec = &iov->iov[0];
+
+ if (copy_from_user(vec, local_vec, args->nr_local *
+ sizeof(struct rds_iovec)))
+ return -EFAULT;
+ iov->len = args->nr_local;
+
+ /* figure out the number of pages in the vector */
+ for (i = 0; i < args->nr_local; i++, vec++) {
+
+ nr_pages = rds_pages_in_vec(vec);
+ if (nr_pages == 0)
+ return -EINVAL;
+
+ tot_pages += nr_pages;
+
+ /*
+ * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
+ * so tot_pages cannot overflow without first going negative.
+ */
+ if (tot_pages < 0)
+ return -EINVAL;
+ }
+
+ return tot_pages * sizeof(struct scatterlist);
+}
+
+/*
+ * The application asks for a RDMA transfer.
+ * Extract all arguments and set up the rdma_op
+ */
+int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
+ struct cmsghdr *cmsg,
+ struct rds_iov_vector *vec)
+{
+ struct rds_rdma_args *args;
+ struct rm_rdma_op *op = &rm->rdma;
+ int nr_pages;
+ unsigned int nr_bytes;
+ struct page **pages = NULL;
+ struct rds_iovec *iovs;
+ unsigned int i, j;
+ int ret = 0;
+
+ if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_rdma_args))
+ || rm->rdma.op_active)
+ return -EINVAL;
+
+ args = CMSG_DATA(cmsg);
+
+ if (ipv6_addr_any(&rs->rs_bound_addr)) {
+ ret = -ENOTCONN; /* XXX not a great errno */
+ goto out_ret;
+ }
+
+ if (args->nr_local > UIO_MAXIOV) {
+ ret = -EMSGSIZE;
+ goto out_ret;
+ }
+
+ if (vec->len != args->nr_local) {
+ ret = -EINVAL;
+ goto out_ret;
+ }
+
+ iovs = vec->iov;
+
+ nr_pages = rds_rdma_pages(iovs, args->nr_local);
+ if (nr_pages < 0) {
+ ret = -EINVAL;
+ goto out_ret;
+ }
+
+ pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
+ if (!pages) {
+ ret = -ENOMEM;
+ goto out_ret;
+ }
+
+ op->op_write = !!(args->flags & RDS_RDMA_READWRITE);
+ op->op_fence = !!(args->flags & RDS_RDMA_FENCE);
+ op->op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
+ op->op_silent = !!(args->flags & RDS_RDMA_SILENT);
+ op->op_active = 1;
+ op->op_recverr = rs->rs_recverr;
+ WARN_ON(!nr_pages);
+ op->op_sg = rds_message_alloc_sgs(rm, nr_pages);
+ if (!op->op_sg) {
+ ret = -ENOMEM;
+ goto out_pages;
+ }
+
+ if (op->op_notify || op->op_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->op_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL);
+ if (!op->op_notifier) {
+ ret = -ENOMEM;
+ goto out_pages;
+ }
+ op->op_notifier->n_user_token = args->user_token;
+ op->op_notifier->n_status = RDS_RDMA_SUCCESS;
+
+ /* Enable rmda notification on data operation for composite
+ * rds messages and make sure notification is enabled only
+ * for the data operation which follows it so that application
+ * gets notified only after full message gets delivered.
+ */
+ if (rm->data.op_sg) {
+ rm->rdma.op_notify = 0;
+ rm->data.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
+ }
+ }
+
+ /* 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->op_rkey = rds_rdma_cookie_key(args->cookie);
+ op->op_remote_addr = args->remote_vec.addr + rds_rdma_cookie_offset(args->cookie);
+
+ nr_bytes = 0;
+
+ rdsdebug("RDS: rdma prepare nr_local %llu rva %llx rkey %x\n",
+ (unsigned long long)args->nr_local,
+ (unsigned long long)args->remote_vec.addr,
+ op->op_rkey);
+
+ for (i = 0; i < args->nr_local; i++) {
+ struct rds_iovec *iov = &iovs[i];
+ /* don't need to check, rds_rdma_pages() verified nr will be +nonzero */
+ unsigned int nr = rds_pages_in_vec(iov);
+
+ rs->rs_user_addr = iov->addr;
+ rs->rs_user_bytes = iov->bytes;
+
+ /* If it's a WRITE operation, we want to pin the pages for reading.
+ * If it's a READ operation, we need to pin the pages for writing.
+ */
+ ret = rds_pin_pages(iov->addr, nr, pages, !op->op_write);
+ if (ret < 0)
+ goto out_pages;
+ else
+ ret = 0;
+
+ rdsdebug("RDS: nr_bytes %u nr %u iov->bytes %llu iov->addr %llx\n",
+ nr_bytes, nr, iov->bytes, iov->addr);
+
+ nr_bytes += iov->bytes;
+
+ for (j = 0; j < nr; j++) {
+ unsigned int offset = iov->addr & ~PAGE_MASK;
+ struct scatterlist *sg;
+
+ sg = &op->op_sg[op->op_nents + j];
+ sg_set_page(sg, pages[j],
+ min_t(unsigned int, iov->bytes, PAGE_SIZE - offset),
+ offset);
+
+ rdsdebug("RDS: sg->offset %x sg->len %x iov->addr %llx iov->bytes %llu\n",
+ sg->offset, sg->length, iov->addr, iov->bytes);
+
+ iov->addr += sg->length;
+ iov->bytes -= sg->length;
+ }
+
+ op->op_nents += nr;
+ }
+
+ if (nr_bytes > args->remote_vec.bytes) {
+ rdsdebug("RDS nr_bytes %u remote_bytes %u do not match\n",
+ nr_bytes,
+ (unsigned int) args->remote_vec.bytes);
+ ret = -EINVAL;
+ goto out_pages;
+ }
+ op->op_bytes = nr_bytes;
+
+out_pages:
+ kfree(pages);
+out_ret:
+ if (ret)
+ rds_rdma_free_op(op);
+ else
+ rds_stats_inc(s_send_rdma);
+
+ return ret;
+}
+
+/*
+ * The application wants us to pass an RDMA destination (aka MR)
+ * to the remote
+ */
+int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
+ struct cmsghdr *cmsg)
+{
+ unsigned long flags;
+ struct rds_mr *mr;
+ u32 r_key;
+ int err = 0;
+
+ if (cmsg->cmsg_len < CMSG_LEN(sizeof(rds_rdma_cookie_t)) ||
+ rm->m_rdma_cookie != 0)
+ return -EINVAL;
+
+ 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 = rds_rdma_cookie_key(rm->m_rdma_cookie);
+
+ spin_lock_irqsave(&rs->rs_rdma_lock, flags);
+ mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
+ if (!mr)
+ err = -EINVAL; /* invalid r_key */
+ else
+ refcount_inc(&mr->r_refcount);
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+
+ if (mr) {
+ mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE);
+ rm->rdma.op_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 rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
+ struct cmsghdr *cmsg)
+{
+ if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_get_mr_args)) ||
+ rm->m_rdma_cookie != 0)
+ return -EINVAL;
+
+ return __rds_rdma_map(rs, CMSG_DATA(cmsg), &rm->m_rdma_cookie,
+ &rm->rdma.op_rdma_mr, rm->m_conn_path);
+}
+
+/*
+ * Fill in rds_message for an atomic request.
+ */
+int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
+ struct cmsghdr *cmsg)
+{
+ struct page *page = NULL;
+ struct rds_atomic_args *args;
+ int ret = 0;
+
+ if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_atomic_args))
+ || rm->atomic.op_active)
+ return -EINVAL;
+
+ args = CMSG_DATA(cmsg);
+
+ /* Nonmasked & masked cmsg ops converted to masked hw ops */
+ switch (cmsg->cmsg_type) {
+ case RDS_CMSG_ATOMIC_FADD:
+ rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
+ rm->atomic.op_m_fadd.add = args->fadd.add;
+ rm->atomic.op_m_fadd.nocarry_mask = 0;
+ break;
+ case RDS_CMSG_MASKED_ATOMIC_FADD:
+ rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
+ rm->atomic.op_m_fadd.add = args->m_fadd.add;
+ rm->atomic.op_m_fadd.nocarry_mask = args->m_fadd.nocarry_mask;
+ break;
+ case RDS_CMSG_ATOMIC_CSWP:
+ rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
+ rm->atomic.op_m_cswp.compare = args->cswp.compare;
+ rm->atomic.op_m_cswp.swap = args->cswp.swap;
+ rm->atomic.op_m_cswp.compare_mask = ~0;
+ rm->atomic.op_m_cswp.swap_mask = ~0;
+ break;
+ case RDS_CMSG_MASKED_ATOMIC_CSWP:
+ rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
+ rm->atomic.op_m_cswp.compare = args->m_cswp.compare;
+ rm->atomic.op_m_cswp.swap = args->m_cswp.swap;
+ rm->atomic.op_m_cswp.compare_mask = args->m_cswp.compare_mask;
+ rm->atomic.op_m_cswp.swap_mask = args->m_cswp.swap_mask;
+ break;
+ default:
+ BUG(); /* should never happen */
+ }
+
+ rm->atomic.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
+ rm->atomic.op_silent = !!(args->flags & RDS_RDMA_SILENT);
+ rm->atomic.op_active = 1;
+ rm->atomic.op_recverr = rs->rs_recverr;
+ rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1);
+ if (!rm->atomic.op_sg) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ /* verify 8 byte-aligned */
+ if (args->local_addr & 0x7) {
+ ret = -EFAULT;
+ goto err;
+ }
+
+ ret = rds_pin_pages(args->local_addr, 1, &page, 1);
+ if (ret != 1)
+ goto err;
+ ret = 0;
+
+ sg_set_page(rm->atomic.op_sg, page, 8, offset_in_page(args->local_addr));
+
+ if (rm->atomic.op_notify || rm->atomic.op_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.
+ */
+ rm->atomic.op_notifier = kmalloc(sizeof(*rm->atomic.op_notifier), GFP_KERNEL);
+ if (!rm->atomic.op_notifier) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ rm->atomic.op_notifier->n_user_token = args->user_token;
+ rm->atomic.op_notifier->n_status = RDS_RDMA_SUCCESS;
+ }
+
+ rm->atomic.op_rkey = rds_rdma_cookie_key(args->cookie);
+ rm->atomic.op_remote_addr = args->remote_addr + rds_rdma_cookie_offset(args->cookie);
+
+ return ret;
+err:
+ if (page)
+ put_page(page);
+ rm->atomic.op_active = 0;
+ kfree(rm->atomic.op_notifier);
+
+ return ret;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 04:32:04 +0000