Commit 741a49a4 authored by Karsten Graul's avatar Karsten Graul Committed by David S. Miller
Browse files

net/smc: do not call dma sync for unmapped memory 



The dma related ...sync_sg... functions check the link state before the
dma function is actually called. But the check in smc_link_usable()
allows links in ACTIVATING state which are not yet mapped to dma memory.
Under high load it may happen that the sync_sg functions are called for
such a link which results in an debug output like
   DMA-API: mlx5_core 0002:00:00.0: device driver tries to sync
   DMA memory it has not allocated [device address=0x0000000103370000]
   [size=65536 bytes]
To fix that introduce a helper to check for the link state ACTIVE and
use it where appropriate. And move the link state update to ACTIVATING
to the end of smcr_link_init() when most initial setup is done.

Reviewed-by: default avatarUrsula Braun <ubraun@linux.ibm.com>
Fixes: d854fcbf ("net/smc: add new link state and related helpers")
Signed-off-by: default avatarKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b9979c2e

net/smc/af_smc.c

+1 −1
Original line number Diff line number Diff line
@@ -352,7 +352,7 @@ static int smcr_lgr_reg_rmbs(struct smc_link *link, 
	 */

	mutex_lock(&lgr->llc_conf_mutex);

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

		if (lgr->lnk[i].state != SMC_LNK_ACTIVE)

		if (!smc_link_active(&lgr->lnk[i]))

			continue;

		rc = smcr_link_reg_rmb(&lgr->lnk[i], rmb_desc);

		if (rc)

net/smc/smc_core.c

+7 −8
Original line number Diff line number Diff line
@@ -318,7 +318,6 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, 


	get_device(&ini->ib_dev->ibdev->dev);

	atomic_inc(&ini->ib_dev->lnk_cnt);

	lnk->state = SMC_LNK_ACTIVATING;

	lnk->link_id = smcr_next_link_id(lgr);

	lnk->lgr = lgr;

	lnk->link_idx = link_idx;
@@ -354,6 +353,7 @@ int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk, 
	rc = smc_wr_create_link(lnk);

	if (rc)

		goto destroy_qp;

	lnk->state = SMC_LNK_ACTIVATING;

	return 0;



destroy_qp:
@@ -542,8 +542,7 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, 
	smc_wr_wakeup_tx_wait(from_lnk);



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

		if (lgr->lnk[i].state != SMC_LNK_ACTIVE ||

		    i == from_lnk->link_idx)

		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)

			continue;

		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&

		    from_lnk->ibport == lgr->lnk[i].ibport) {
@@ -1269,7 +1268,7 @@ static bool smcr_lgr_match(struct smc_link_group *lgr, 
		return false;



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

		if (lgr->lnk[i].state != SMC_LNK_ACTIVE)

		if (!smc_link_active(&lgr->lnk[i]))

			continue;

		if ((lgr->role == SMC_SERV || lgr->lnk[i].peer_qpn == clcqpn) &&

		    !memcmp(lgr->lnk[i].peer_gid, &lcl->gid, SMC_GID_SIZE) &&
@@ -1717,14 +1716,14 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb) 


void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)

{

	if (!conn->lgr || conn->lgr->is_smcd || !smc_link_usable(conn->lnk))

	if (!conn->lgr || conn->lgr->is_smcd || !smc_link_active(conn->lnk))

		return;

	smc_ib_sync_sg_for_cpu(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);

}



void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)

{

	if (!conn->lgr || conn->lgr->is_smcd || !smc_link_usable(conn->lnk))

	if (!conn->lgr || conn->lgr->is_smcd || !smc_link_active(conn->lnk))

		return;

	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);

}
@@ -1736,7 +1735,7 @@ void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn) 
	if (!conn->lgr || conn->lgr->is_smcd)

		return;

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

		if (!smc_link_usable(&conn->lgr->lnk[i]))

		if (!smc_link_active(&conn->lgr->lnk[i]))

			continue;

		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,

				       DMA_FROM_DEVICE);
@@ -1750,7 +1749,7 @@ void smc_rmb_sync_sg_for_device(struct smc_connection *conn) 
	if (!conn->lgr || conn->lgr->is_smcd)

		return;

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

		if (!smc_link_usable(&conn->lgr->lnk[i]))

		if (!smc_link_active(&conn->lgr->lnk[i]))

			continue;

		smc_ib_sync_sg_for_device(&conn->lgr->lnk[i], conn->rmb_desc,

					  DMA_FROM_DEVICE);

net/smc/smc_core.h

+5 −0
Original line number Diff line number Diff line
@@ -349,6 +349,11 @@ static inline bool smc_link_usable(struct smc_link *lnk) 
	return true;

}



static inline bool smc_link_active(struct smc_link *lnk)

{

	return lnk->state == SMC_LNK_ACTIVE;

}



struct smc_sock;

struct smc_clc_msg_accept_confirm;

struct smc_clc_msg_local;

net/smc/smc_llc.c

+5 −5
Original line number Diff line number Diff line
@@ -428,7 +428,7 @@ static int smc_llc_send_confirm_rkey(struct smc_link *send_link, 
	rtok_ix = 1;

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

		link = &send_link->lgr->lnk[i];

		if (link->state == SMC_LNK_ACTIVE && link != send_link) {

		if (smc_link_active(link) && link != send_link) {

			rkeyllc->rtoken[rtok_ix].link_id = link->link_id;

			rkeyllc->rtoken[rtok_ix].rmb_key =

				htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
@@ -944,7 +944,7 @@ static int smc_llc_active_link_count(struct smc_link_group *lgr) 
	int i, link_count = 0;



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

		if (!smc_link_usable(&lgr->lnk[i]))

		if (!smc_link_active(&lgr->lnk[i]))

			continue;

		link_count++;

	}
@@ -1622,7 +1622,7 @@ static void smc_llc_rx_response(struct smc_link *link, 


	switch (llc_type) {

	case SMC_LLC_TEST_LINK:

		if (link->state == SMC_LNK_ACTIVE)

		if (smc_link_active(link))

			complete(&link->llc_testlink_resp);

		break;

	case SMC_LLC_ADD_LINK:
@@ -1706,7 +1706,7 @@ static void smc_llc_testlink_work(struct work_struct *work) 
	u8 user_data[16] = { 0 };

	int rc;



	if (link->state != SMC_LNK_ACTIVE)

	if (!smc_link_active(link))

		return;		/* don't reschedule worker */

	expire_time = link->wr_rx_tstamp + link->llc_testlink_time;

	if (time_is_after_jiffies(expire_time)) {
@@ -1718,7 +1718,7 @@ static void smc_llc_testlink_work(struct work_struct *work) 
	/* receive TEST LINK response over RoCE fabric */

	rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,

						       SMC_LLC_WAIT_TIME);

	if (link->state != SMC_LNK_ACTIVE)

	if (!smc_link_active(link))

		return;		/* link state changed */

	if (rc <= 0) {

		smcr_link_down_cond_sched(link);

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