Commit 3e034725 authored by Ursula Braun's avatar Ursula Braun Committed by David S. Miller
Browse files

net/smc: common functions for RMBs and send buffers 



Creation and deletion of SMC receive and send buffers shares a high
amount of common code . This patch introduces common functions to get
rid of duplicate code.

Signed-off-by: default avatarUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9d8fb617

net/smc/af_smc.c

+4 −12
Original line number Diff line number Diff line
@@ -436,12 +436,8 @@ static int smc_connect_rdma(struct smc_sock *smc) 


	smc_conn_save_peer_info(smc, &aclc);



	rc = smc_sndbuf_create(smc);

	if (rc) {

		reason_code = SMC_CLC_DECL_MEM;

		goto decline_rdma_unlock;

	}

	rc = smc_rmb_create(smc);

	/* create send buffer and rmb */

	rc = smc_buf_create(smc);

	if (rc) {

		reason_code = SMC_CLC_DECL_MEM;

		goto decline_rdma_unlock;
@@ -813,12 +809,8 @@ static void smc_listen_work(struct work_struct *work) 
	}

	link = &new_smc->conn.lgr->lnk[SMC_SINGLE_LINK];



	rc = smc_sndbuf_create(new_smc);

	if (rc) {

		reason_code = SMC_CLC_DECL_MEM;

		goto decline_rdma;

	}

	rc = smc_rmb_create(new_smc);

	/* create send buffer and rmb */

	rc = smc_buf_create(new_smc);

	if (rc) {

		reason_code = SMC_CLC_DECL_MEM;

		goto decline_rdma;

net/smc/smc_core.c

+143 −205
Original line number Diff line number Diff line
@@ -206,16 +206,12 @@ out: 
	return rc;

}



static void smc_sndbuf_unuse(struct smc_connection *conn)

static void smc_buf_unuse(struct smc_connection *conn)

{

	if (conn->sndbuf_desc) {

		conn->sndbuf_desc->used = 0;

		conn->sndbuf_size = 0;

	}

}



static void smc_rmb_unuse(struct smc_connection *conn)

{

	if (conn->rmb_desc) {

		conn->rmb_desc->reused = true;

		conn->rmb_desc->used = 0;
@@ -232,8 +228,7 @@ void smc_conn_free(struct smc_connection *conn) 
		return;

	smc_cdc_tx_dismiss_slots(conn);

	smc_lgr_unregister_conn(conn);

	smc_rmb_unuse(conn);

	smc_sndbuf_unuse(conn);

	smc_buf_unuse(conn);

}



static void smc_link_clear(struct smc_link *lnk)
@@ -246,51 +241,57 @@ static void smc_link_clear(struct smc_link *lnk) 
	smc_wr_free_link_mem(lnk);

}



static void smc_lgr_free_sndbufs(struct smc_link_group *lgr)

static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk,

			 bool is_rmb)

{

	struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];

	struct smc_buf_desc *sndbuf_desc, *bf_desc;

	int i;



	for (i = 0; i < SMC_RMBE_SIZES; i++) {

		list_for_each_entry_safe(sndbuf_desc, bf_desc, &lgr->sndbufs[i],

					 list) {

			list_del(&sndbuf_desc->list);

			smc_ib_buf_unmap_sg(lnk->smcibdev, sndbuf_desc,

	if (is_rmb) {

		if (buf_desc->mr_rx[SMC_SINGLE_LINK])

			smc_ib_put_memory_region(

					buf_desc->mr_rx[SMC_SINGLE_LINK]);

		smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,

				    DMA_FROM_DEVICE);

	} else {

		smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,

				    DMA_TO_DEVICE);

			sg_free_table(&sndbuf_desc->sgt[SMC_SINGLE_LINK]);

			free_pages((unsigned long)sndbuf_desc->cpu_addr,

				   sndbuf_desc->order);

			kfree(sndbuf_desc);

		}

	}

	sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);

	if (buf_desc->cpu_addr)

		free_pages((unsigned long)buf_desc->cpu_addr, buf_desc->order);

	kfree(buf_desc);

}



static void smc_lgr_free_rmbs(struct smc_link_group *lgr)

static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)

{

	struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];

	struct smc_buf_desc *rmb_desc, *bf_desc;

	struct smc_buf_desc *buf_desc, *bf_desc;

	struct list_head *buf_list;

	int i;



	for (i = 0; i < SMC_RMBE_SIZES; i++) {

		list_for_each_entry_safe(rmb_desc, bf_desc, &lgr->rmbs[i],

		if (is_rmb)

			buf_list = &lgr->rmbs[i];

		else

			buf_list = &lgr->sndbufs[i];

		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,

					 list) {

			list_del(&rmb_desc->list);

			smc_ib_put_memory_region(

					rmb_desc->mr_rx[SMC_SINGLE_LINK]);

			smc_ib_buf_unmap_sg(lnk->smcibdev, rmb_desc,

					    DMA_FROM_DEVICE);

			kfree(rmb_desc->cpu_addr);

			kfree(rmb_desc);

			list_del(&buf_desc->list);

			smc_buf_free(buf_desc, lnk, is_rmb);

		}

	}

}



static void smc_lgr_free_bufs(struct smc_link_group *lgr)

{

	/* free send buffers */

	__smc_lgr_free_bufs(lgr, false);

	/* free rmbs */

	__smc_lgr_free_bufs(lgr, true);

}



/* remove a link group */

void smc_lgr_free(struct smc_link_group *lgr)

{

	smc_lgr_free_rmbs(lgr);

	smc_lgr_free_sndbufs(lgr);

	smc_lgr_free_bufs(lgr);

	smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);

	kfree(lgr);

}
@@ -455,45 +456,25 @@ out: 
	return rc ? rc : local_contact;

}



/* try to reuse a sndbuf description slot of the sndbufs list for a certain

 * buf_size; if not available, return NULL

 */

static inline

struct smc_buf_desc *smc_sndbuf_get_slot(struct smc_link_group *lgr,

					 int compressed_bufsize)

{

	struct smc_buf_desc *sndbuf_slot;



	read_lock_bh(&lgr->sndbufs_lock);

	list_for_each_entry(sndbuf_slot, &lgr->sndbufs[compressed_bufsize],

			    list) {

		if (cmpxchg(&sndbuf_slot->used, 0, 1) == 0) {

			read_unlock_bh(&lgr->sndbufs_lock);

			return sndbuf_slot;

		}

	}

	read_unlock_bh(&lgr->sndbufs_lock);

	return NULL;

}



/* try to reuse an rmb description slot of the rmbs list for a certain

 * rmbe_size; if not available, return NULL

/* try to reuse a sndbuf or rmb description slot for a certain

 * buffer size; if not available, return NULL

 */

static inline

struct smc_buf_desc *smc_rmb_get_slot(struct smc_link_group *lgr,

				      int compressed_bufsize)

struct smc_buf_desc *smc_buf_get_slot(struct smc_link_group *lgr,

				      int compressed_bufsize,

				      rwlock_t *lock,

				      struct list_head *buf_list)

{

	struct smc_buf_desc *rmb_slot;

	struct smc_buf_desc *buf_slot;



	read_lock_bh(&lgr->rmbs_lock);

	list_for_each_entry(rmb_slot, &lgr->rmbs[compressed_bufsize],

			    list) {

		if (cmpxchg(&rmb_slot->used, 0, 1) == 0) {

			read_unlock_bh(&lgr->rmbs_lock);

			return rmb_slot;

	read_lock_bh(lock);

	list_for_each_entry(buf_slot, buf_list, list) {

		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {

			read_unlock_bh(lock);

			return buf_slot;

		}

	}

	read_unlock_bh(&lgr->rmbs_lock);

	read_unlock_bh(lock);

	return NULL;

}
@@ -506,185 +487,142 @@ static inline int smc_rmb_wnd_update_limit(int rmbe_size) 
	return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);

}



/* create the tx buffer for an SMC socket */

int smc_sndbuf_create(struct smc_sock *smc)

static int __smc_buf_create(struct smc_sock *smc, bool is_rmb)

{

	struct smc_connection *conn = &smc->conn;

	struct smc_link_group *lgr = conn->lgr;

	struct smc_buf_desc *sndbuf_desc;

	struct smc_buf_desc *buf_desc = NULL;

	struct list_head *buf_list;

	int bufsize, bufsize_short;

	struct smc_link *lnk;

	int sk_buf_size;

	rwlock_t *lock;

	int rc;



	lnk = &lgr->lnk[SMC_SINGLE_LINK];

	if (is_rmb)

		/* use socket recv buffer size (w/o overhead) as start value */

		sk_buf_size = smc->sk.sk_rcvbuf / 2;

	else

		/* use socket send buffer size (w/o overhead) as start value */

		sk_buf_size = smc->sk.sk_sndbuf / 2;



	for (bufsize_short = smc_compress_bufsize(smc->sk.sk_sndbuf / 2);

	     bufsize_short >= 0; bufsize_short--) {

		bufsize = smc_uncompress_bufsize(bufsize_short);

		if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)

			continue;



		/* check for reusable sndbuf_slot in the link group */

		sndbuf_desc = smc_sndbuf_get_slot(lgr, bufsize_short);

		if (sndbuf_desc) {

			memset(sndbuf_desc->cpu_addr, 0, bufsize);

			break; /* found reusable slot */

		}

		/* try to alloc a new send buffer */

		sndbuf_desc = kzalloc(sizeof(*sndbuf_desc), GFP_KERNEL);

		if (!sndbuf_desc)

			break; /* give up with -ENOMEM */



		sndbuf_desc->cpu_addr =

			(void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN |

						 __GFP_NOMEMALLOC |

						 __GFP_NORETRY | __GFP_ZERO,

						 get_order(bufsize));

		if (!sndbuf_desc->cpu_addr) {

			kfree(sndbuf_desc);

			sndbuf_desc = NULL;

			/* if send buffer allocation has failed,

			 * try a smaller one

			 */

			continue;

		}

		sndbuf_desc->order = get_order(bufsize);



		rc = sg_alloc_table(&sndbuf_desc->sgt[SMC_SINGLE_LINK], 1,

				    GFP_KERNEL);

		if (rc) {

			free_pages((unsigned long)sndbuf_desc->cpu_addr,

				   sndbuf_desc->order);

			kfree(sndbuf_desc);

			sndbuf_desc = NULL;

			continue;

		}

		sg_set_buf(sndbuf_desc->sgt[SMC_SINGLE_LINK].sgl,

			   sndbuf_desc->cpu_addr, bufsize);



		rc = smc_ib_buf_map_sg(lgr->lnk[SMC_SINGLE_LINK].smcibdev,

				       sndbuf_desc, DMA_TO_DEVICE);

		if (rc != 1) {

			sg_free_table(&sndbuf_desc->sgt[SMC_SINGLE_LINK]);

			free_pages((unsigned long)sndbuf_desc->cpu_addr,

				   sndbuf_desc->order);

			kfree(sndbuf_desc);

			sndbuf_desc = NULL;

			continue; /* if mapping failed, try smaller one */

		}



		sndbuf_desc->used = 1;

		write_lock_bh(&lgr->sndbufs_lock);

		list_add(&sndbuf_desc->list, &lgr->sndbufs[bufsize_short]);

		write_unlock_bh(&lgr->sndbufs_lock);

		break;

	}

	if (sndbuf_desc && sndbuf_desc->cpu_addr) {

		conn->sndbuf_desc = sndbuf_desc;

		conn->sndbuf_size = bufsize;

		smc->sk.sk_sndbuf = bufsize * 2;

		atomic_set(&conn->sndbuf_space, bufsize);

		return 0;

		if (is_rmb) {

			lock = &lgr->rmbs_lock;

			buf_list = &lgr->rmbs[bufsize_short];

		} else {

		return -ENOMEM;

	}

			lock = &lgr->sndbufs_lock;

			buf_list = &lgr->sndbufs[bufsize_short];

		}



/* create the RMB for an SMC socket (even though the SMC protocol

 * allows more than one RMB-element per RMB, the Linux implementation

 * uses just one RMB-element per RMB, i.e. uses an extra RMB for every

 * connection in a link group

 */

int smc_rmb_create(struct smc_sock *smc)

{

	struct smc_connection *conn = &smc->conn;

	struct smc_link_group *lgr = conn->lgr;

	struct smc_buf_desc *rmb_desc;

	int bufsize, bufsize_short;

	int rc;



	/* use socket recv buffer size (w/o overhead) as start value */

	for (bufsize_short = smc_compress_bufsize(smc->sk.sk_rcvbuf / 2);

	     bufsize_short >= 0; bufsize_short--) {

		bufsize = smc_uncompress_bufsize(bufsize_short);

		if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)

			continue;



		/* check for reusable rmb_slot in the link group */

		rmb_desc = smc_rmb_get_slot(lgr, bufsize_short);

		if (rmb_desc) {

			memset(rmb_desc->cpu_addr, 0, bufsize);

		/* check for reusable slot in the link group */

		buf_desc = smc_buf_get_slot(lgr, bufsize_short, lock, buf_list);

		if (buf_desc) {

			memset(buf_desc->cpu_addr, 0, bufsize);

			break; /* found reusable slot */

		}



		/* try to alloc a new RMB */

		rmb_desc = kzalloc(sizeof(*rmb_desc), GFP_KERNEL);

		if (!rmb_desc)

		/* try to allocate the determined number of pages */

		buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);

		if (!buf_desc)

			break; /* give up with -ENOMEM */

		rmb_desc->cpu_addr =



		buf_desc->cpu_addr =

			(void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN |

						 __GFP_NOMEMALLOC |

						 __GFP_NORETRY | __GFP_ZERO,

						 get_order(bufsize));

		if (!rmb_desc->cpu_addr) {

			kfree(rmb_desc);

			rmb_desc = NULL;

		if (!buf_desc->cpu_addr) {

			kfree(buf_desc);

			buf_desc = NULL;

			continue;

		}

		rmb_desc->order = get_order(bufsize);



		rc = sg_alloc_table(&rmb_desc->sgt[SMC_SINGLE_LINK], 1,

		rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,

				    GFP_KERNEL);

		if (rc) {

			free_pages((unsigned long)rmb_desc->cpu_addr,

				   rmb_desc->order);

			kfree(rmb_desc);

			rmb_desc = NULL;

			smc_buf_free(buf_desc, lnk, is_rmb);

			buf_desc = NULL;

			continue;

		}

		sg_set_buf(rmb_desc->sgt[SMC_SINGLE_LINK].sgl,

			   rmb_desc->cpu_addr, bufsize);

		sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,

			   buf_desc->cpu_addr, bufsize);



		rc = smc_ib_buf_map_sg(lgr->lnk[SMC_SINGLE_LINK].smcibdev,

				       rmb_desc, DMA_FROM_DEVICE);

		/* map sg table to DMA address */

		rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc, is_rmb ?

				       DMA_FROM_DEVICE : DMA_TO_DEVICE);

		/* SMC protocol depends on mapping to one DMA address only */

		if (rc != 1)  {

			sg_free_table(&rmb_desc->sgt[SMC_SINGLE_LINK]);

			free_pages((unsigned long)rmb_desc->cpu_addr,

				   rmb_desc->order);

			kfree(rmb_desc);

			rmb_desc = NULL;

			smc_buf_free(buf_desc, lnk, is_rmb);

			buf_desc = NULL;

		continue; /* if mapping failed, try smaller one */

		}

		rc = smc_ib_get_memory_region(lgr->lnk[SMC_SINGLE_LINK].roce_pd,



		/* create a new memory region for the RMB */

		if (is_rmb) {

			rc = smc_ib_get_memory_region(lnk->roce_pd,

						      IB_ACCESS_REMOTE_WRITE |

						      IB_ACCESS_LOCAL_WRITE,

					      rmb_desc);

						      buf_desc);

			if (rc) {

			smc_ib_buf_unmap_sg(lgr->lnk[SMC_SINGLE_LINK].smcibdev,

					    rmb_desc, DMA_FROM_DEVICE);

			sg_free_table(&rmb_desc->sgt[SMC_SINGLE_LINK]);

			free_pages((unsigned long)rmb_desc->cpu_addr,

				   rmb_desc->order);

			kfree(rmb_desc);

			rmb_desc = NULL;

				smc_buf_free(buf_desc, lnk, is_rmb);

				buf_desc = NULL;

				continue;

			}

		}



		rmb_desc->used = 1;

		write_lock_bh(&lgr->rmbs_lock);

		list_add(&rmb_desc->list, &lgr->rmbs[bufsize_short]);

		write_unlock_bh(&lgr->rmbs_lock);

		break;

		buf_desc->used = 1;

		write_lock_bh(lock);

		list_add(&buf_desc->list, buf_list);

		write_unlock_bh(lock);

		break; /* found */

	}

	if (rmb_desc && rmb_desc->cpu_addr) {

		conn->rmb_desc = rmb_desc;



	if (!buf_desc || !buf_desc->cpu_addr)

		return -ENOMEM;



	if (is_rmb) {

		conn->rmb_desc = buf_desc;

		conn->rmbe_size = bufsize;

		conn->rmbe_size_short = bufsize_short;

		smc->sk.sk_rcvbuf = bufsize * 2;

		atomic_set(&conn->bytes_to_rcv, 0);

		conn->rmbe_update_limit = smc_rmb_wnd_update_limit(bufsize);

		return 0;

	} else {

		return -ENOMEM;

		conn->sndbuf_desc = buf_desc;

		conn->sndbuf_size = bufsize;

		smc->sk.sk_sndbuf = bufsize * 2;

		atomic_set(&conn->sndbuf_space, bufsize);

	}

	return 0;

}



/* create the send and receive buffer for an SMC socket;

 * receive buffers are called RMBs;

 * (even though the SMC protocol allows more than one RMB-element per RMB,

 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an

 * extra RMB for every connection in a link group

 */

int smc_buf_create(struct smc_sock *smc)

{

	int rc;



	/* create send buffer */

	rc = __smc_buf_create(smc, false);

	if (rc)

		return rc;

	/* create rmb */

	rc = __smc_buf_create(smc, true);

	if (rc)

		smc_buf_free(smc->conn.sndbuf_desc,

			     &smc->conn.lgr->lnk[SMC_SINGLE_LINK], false);

	return rc;

}



static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)

net/smc/smc_core.h

+1 −2
Original line number Diff line number Diff line
@@ -186,8 +186,7 @@ struct smc_clc_msg_accept_confirm; 


void smc_lgr_free(struct smc_link_group *lgr);

void smc_lgr_terminate(struct smc_link_group *lgr);

int smc_sndbuf_create(struct smc_sock *smc);

int smc_rmb_create(struct smc_sock *smc);

int smc_buf_create(struct smc_sock *smc);

int smc_rmb_rtoken_handling(struct smc_connection *conn,

			    struct smc_clc_msg_accept_confirm *clc);

#endif