1 files changed, 366 insertions, 0 deletions
diff --git a/net/rds/message.c b/net/rds/message.c
new file mode 100644
index 000000000..756c73729
--- /dev/null
+++ b/net/rds/message.c
@@ -0,0 +1,366 @@
+/*
+ * Copyright (c) 2006 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 <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+#include "rds.h"
+
+static unsigned int	rds_exthdr_size[__RDS_EXTHDR_MAX] = {
+[RDS_EXTHDR_NONE]	= 0,
+[RDS_EXTHDR_VERSION]	= sizeof(struct rds_ext_header_version),
+[RDS_EXTHDR_RDMA]	= sizeof(struct rds_ext_header_rdma),
+[RDS_EXTHDR_RDMA_DEST]	= sizeof(struct rds_ext_header_rdma_dest),
+};
+
+
+void rds_message_addref(struct rds_message *rm)
+{
+	rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
+	atomic_inc(&rm->m_refcount);
+}
+EXPORT_SYMBOL_GPL(rds_message_addref);
+
+/*
+ * This relies on dma_map_sg() not touching sg[].page during merging.
+ */
+static void rds_message_purge(struct rds_message *rm)
+{
+	unsigned long i;
+
+	if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
+		return;
+
+	for (i = 0; i < rm->data.op_nents; i++) {
+		rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i]));
+		/* XXX will have to put_page for page refs */
+		__free_page(sg_page(&rm->data.op_sg[i]));
+	}
+	rm->data.op_nents = 0;
+
+	if (rm->rdma.op_active)
+		rds_rdma_free_op(&rm->rdma);
+	if (rm->rdma.op_rdma_mr)
+		rds_mr_put(rm->rdma.op_rdma_mr);
+
+	if (rm->atomic.op_active)
+		rds_atomic_free_op(&rm->atomic);
+	if (rm->atomic.op_rdma_mr)
+		rds_mr_put(rm->atomic.op_rdma_mr);
+}
+
+void rds_message_put(struct rds_message *rm)
+{
+	rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
+	WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
+	if (atomic_dec_and_test(&rm->m_refcount)) {
+		BUG_ON(!list_empty(&rm->m_sock_item));
+		BUG_ON(!list_empty(&rm->m_conn_item));
+		rds_message_purge(rm);
+
+		kfree(rm);
+	}
+}
+EXPORT_SYMBOL_GPL(rds_message_put);
+
+void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
+				 __be16 dport, u64 seq)
+{
+	hdr->h_flags = 0;
+	hdr->h_sport = sport;
+	hdr->h_dport = dport;
+	hdr->h_sequence = cpu_to_be64(seq);
+	hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
+}
+EXPORT_SYMBOL_GPL(rds_message_populate_header);
+
+int rds_message_add_extension(struct rds_header *hdr, unsigned int type,
+			      const void *data, unsigned int len)
+{
+	unsigned int ext_len = sizeof(u8) + len;
+	unsigned char *dst;
+
+	/* For now, refuse to add more than one extension header */
+	if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
+		return 0;
+
+	if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type])
+		return 0;
+
+	if (ext_len >= RDS_HEADER_EXT_SPACE)
+		return 0;
+	dst = hdr->h_exthdr;
+
+	*dst++ = type;
+	memcpy(dst, data, len);
+
+	dst[len] = RDS_EXTHDR_NONE;
+	return 1;
+}
+EXPORT_SYMBOL_GPL(rds_message_add_extension);
+
+/*
+ * If a message has extension headers, retrieve them here.
+ * Call like this:
+ *
+ * unsigned int pos = 0;
+ *
+ * while (1) {
+ *	buflen = sizeof(buffer);
+ *	type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
+ *	if (type == RDS_EXTHDR_NONE)
+ *		break;
+ *	...
+ * }
+ */
+int rds_message_next_extension(struct rds_header *hdr,
+		unsigned int *pos, void *buf, unsigned int *buflen)
+{
+	unsigned int offset, ext_type, ext_len;
+	u8 *src = hdr->h_exthdr;
+
+	offset = *pos;
+	if (offset >= RDS_HEADER_EXT_SPACE)
+		goto none;
+
+	/* Get the extension type and length. For now, the
+	 * length is implied by the extension type. */
+	ext_type = src[offset++];
+
+	if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
+		goto none;
+	ext_len = rds_exthdr_size[ext_type];
+	if (offset + ext_len > RDS_HEADER_EXT_SPACE)
+		goto none;
+
+	*pos = offset + ext_len;
+	if (ext_len < *buflen)
+		*buflen = ext_len;
+	memcpy(buf, src + offset, *buflen);
+	return ext_type;
+
+none:
+	*pos = RDS_HEADER_EXT_SPACE;
+	*buflen = 0;
+	return RDS_EXTHDR_NONE;
+}
+
+int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
+{
+	struct rds_ext_header_rdma_dest ext_hdr;
+
+	ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
+	ext_hdr.h_rdma_offset = cpu_to_be32(offset);
+	return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
+}
+EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
+
+/*
+ * Each rds_message is allocated with extra space for the scatterlist entries
+ * rds ops will need. This is to minimize memory allocation count. Then, each rds op
+ * can grab SGs when initializing its part of the rds_message.
+ */
+struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
+{
+	struct rds_message *rm;
+
+	if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message))
+		return NULL;
+
+	rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
+	if (!rm)
+		goto out;
+
+	rm->m_used_sgs = 0;
+	rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
+
+	atomic_set(&rm->m_refcount, 1);
+	INIT_LIST_HEAD(&rm->m_sock_item);
+	INIT_LIST_HEAD(&rm->m_conn_item);
+	spin_lock_init(&rm->m_rs_lock);
+	init_waitqueue_head(&rm->m_flush_wait);
+
+out:
+	return rm;
+}
+
+/*
+ * RDS ops use this to grab SG entries from the rm's sg pool.
+ */
+struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
+{
+	struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
+	struct scatterlist *sg_ret;
+
+	WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
+	WARN_ON(!nents);
+
+	if (rm->m_used_sgs + nents > rm->m_total_sgs)
+		return NULL;
+
+	sg_ret = &sg_first[rm->m_used_sgs];
+	sg_init_table(sg_ret, nents);
+	rm->m_used_sgs += nents;
+
+	return sg_ret;
+}
+
+struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
+{
+	struct rds_message *rm;
+	unsigned int i;
+	int num_sgs = ceil(total_len, PAGE_SIZE);
+	int extra_bytes = num_sgs * sizeof(struct scatterlist);
+
+	rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
+	if (!rm)
+		return ERR_PTR(-ENOMEM);
+
+	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
+	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
+	rm->data.op_nents = ceil(total_len, PAGE_SIZE);
+	rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
+	if (!rm->data.op_sg) {
+		rds_message_put(rm);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	for (i = 0; i < rm->data.op_nents; ++i) {
+		sg_set_page(&rm->data.op_sg[i],
+				virt_to_page(page_addrs[i]),
+				PAGE_SIZE, 0);
+	}
+
+	return rm;
+}
+
+int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from)
+{
+	unsigned long to_copy, nbytes;
+	unsigned long sg_off;
+	struct scatterlist *sg;
+	int ret = 0;
+
+	rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
+
+	/*
+	 * now allocate and copy in the data payload.
+	 */
+	sg = rm->data.op_sg;
+	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
+
+	while (iov_iter_count(from)) {
+		if (!sg_page(sg)) {
+			ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
+						       GFP_HIGHUSER);
+			if (ret)
+				return ret;
+			rm->data.op_nents++;
+			sg_off = 0;
+		}
+
+		to_copy = min_t(unsigned long, iov_iter_count(from),
+				sg->length - sg_off);
+
+		rds_stats_add(s_copy_from_user, to_copy);
+		nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
+					     to_copy, from);
+		if (nbytes != to_copy)
+			return -EFAULT;
+
+		sg_off += to_copy;
+
+		if (sg_off == sg->length)
+			sg++;
+	}
+
+	return ret;
+}
+
+int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
+{
+	struct rds_message *rm;
+	struct scatterlist *sg;
+	unsigned long to_copy;
+	unsigned long vec_off;
+	int copied;
+	int ret;
+	u32 len;
+
+	rm = container_of(inc, struct rds_message, m_inc);
+	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
+
+	sg = rm->data.op_sg;
+	vec_off = 0;
+	copied = 0;
+
+	while (iov_iter_count(to) && copied < len) {
+		to_copy = min_t(unsigned long, iov_iter_count(to),
+				sg->length - vec_off);
+		to_copy = min_t(unsigned long, to_copy, len - copied);
+
+		rds_stats_add(s_copy_to_user, to_copy);
+		ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
+					to_copy, to);
+		if (ret != to_copy)
+			return -EFAULT;
+
+		vec_off += to_copy;
+		copied += to_copy;
+
+		if (vec_off == sg->length) {
+			vec_off = 0;
+			sg++;
+		}
+	}
+
+	return copied;
+}
+
+/*
+ * If the message is still on the send queue, wait until the transport
+ * is done with it. This is particularly important for RDMA operations.
+ */
+void rds_message_wait(struct rds_message *rm)
+{
+	wait_event_interruptible(rm->m_flush_wait,
+			!test_bit(RDS_MSG_MAPPED, &rm->m_flags));
+}
+
+void rds_message_unmapped(struct rds_message *rm)
+{
+	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
+	wake_up_interruptible(&rm->m_flush_wait);
+}
+EXPORT_SYMBOL_GPL(rds_message_unmapped);
+