nfp: add async version of mailbox communication

Some control messages must be sent from atomic context.  The mailbox
takes sleeping locks and uses a waitqueue so add a "posted" version
of communication.

Trylock the semaphore and if that's successful kick of the device
communication.  The device communication will be completed from
a workqueue, which will also release the semaphore.

If locks are taken queue the message and return.  Schedule a
different workqueue to take the semaphore and run the communication.
Note that the there are currently no atomic users which would actually
need the return value, so all replies to posted messages are just
freed.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 35 insertions, 5 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 349678425aed..c9c43abb2427 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -40,6 +40,7 @@
 #include <net/vxlan.h>
 
 #include "nfpcore/nfp_nsp.h"
+#include "ccm.h"
 #include "nfp_app.h"
 #include "nfp_net_ctrl.h"
 #include "nfp_net.h"
@@ -229,6 +230,7 @@ static void nfp_net_reconfig_sync_enter(struct nfp_net *nn)
 
 	spin_lock_bh(&nn->reconfig_lock);
 
+	WARN_ON(nn->reconfig_sync_present);
 	nn->reconfig_sync_present = true;
 
 	if (nn->reconfig_timer_active) {
@@ -341,6 +343,24 @@ int nfp_net_mbox_reconfig(struct nfp_net *nn, u32 mbox_cmd)
 	return -nn_readl(nn, mbox + NFP_NET_CFG_MBOX_SIMPLE_RET);
 }
 
+void nfp_net_mbox_reconfig_post(struct nfp_net *nn, u32 mbox_cmd)
+{
+	u32 mbox = nn->tlv_caps.mbox_off;
+
+	nn_writeq(nn, mbox + NFP_NET_CFG_MBOX_SIMPLE_CMD, mbox_cmd);
+
+	nfp_net_reconfig_post(nn, NFP_NET_CFG_UPDATE_MBOX);
+}
+
+int nfp_net_mbox_reconfig_wait_posted(struct nfp_net *nn)
+{
+	u32 mbox = nn->tlv_caps.mbox_off;
+
+	nfp_net_reconfig_wait_posted(nn);
+
+	return -nn_readl(nn, mbox + NFP_NET_CFG_MBOX_SIMPLE_RET);
+}
+
 int nfp_net_mbox_reconfig_and_unlock(struct nfp_net *nn, u32 mbox_cmd)
 {
 	int ret;
@@ -3814,14 +3834,15 @@ nfp_net_alloc(struct pci_dev *pdev, void __iomem *ctrl_bar, bool needs_netdev,
 
 	timer_setup(&nn->reconfig_timer, nfp_net_reconfig_timer, 0);
 
-	skb_queue_head_init(&nn->mbox_cmsg.queue);
-	init_waitqueue_head(&nn->mbox_cmsg.wq);
-
 	err = nfp_net_tlv_caps_parse(&nn->pdev->dev, nn->dp.ctrl_bar,
 				     &nn->tlv_caps);
 	if (err)
 		goto err_free_nn;
 
+	err = nfp_ccm_mbox_alloc(nn);
+	if (err)
+		goto err_free_nn;
+
 	return nn;
 
 err_free_nn:
@@ -3839,7 +3860,7 @@ err_free_nn:
 void nfp_net_free(struct nfp_net *nn)
 {
 	WARN_ON(timer_pending(&nn->reconfig_timer) || nn->reconfig_posted);
-	WARN_ON(!skb_queue_empty(&nn->mbox_cmsg.queue));
+	nfp_ccm_mbox_free(nn);
 
 	if (nn->dp.netdev)
 		free_netdev(nn->dp.netdev);
@@ -4117,9 +4138,13 @@ int nfp_net_init(struct nfp_net *nn)
 	if (nn->dp.netdev) {
 		nfp_net_netdev_init(nn);
 
-		err = nfp_net_tls_init(nn);
+		err = nfp_ccm_mbox_init(nn);
 		if (err)
 			return err;
+
+		err = nfp_net_tls_init(nn);
+		if (err)
+			goto err_clean_mbox;
 	}
 
 	nfp_net_vecs_init(nn);
@@ -4127,6 +4152,10 @@ int nfp_net_init(struct nfp_net *nn)
 	if (!nn->dp.netdev)
 		return 0;
 	return register_netdev(nn->dp.netdev);
+
+err_clean_mbox:
+	nfp_ccm_mbox_clean(nn);
+	return err;
 }
 
 /**
@@ -4139,5 +4168,6 @@ void nfp_net_clean(struct nfp_net *nn)
 		return;
 
 	unregister_netdev(nn->dp.netdev);
+	nfp_ccm_mbox_clean(nn);
 	nfp_net_reconfig_wait_posted(nn);
 }