[PATCH 17/30] rapidio/rionet: add locking into add/remove device

From: Alexandre Bounine
Date: Fri Feb 05 2016 - 18:38:14 EST

Next message: David Daney: "[PATCH v5 0/3] Add host controller drivers for Cavium ThunderX PCI"
Previous message: Alexey Khoroshilov: "[PATCH] mmc: mmc_spi: add checks for dma mapping error"
In reply to: Alexandre Bounine: "[PATCH 27/30] rapidio/tsi721_dma: update error reporting from prep_sg callback"
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Add spinlock protection when handling list of connected peers and ability
to handle new peer device addition after the RIONET device was open.
Before his update RIONET was sending JOIN requests only when it have been
opened, peer devices added later have been missing from this process.

Signed-off-by: Alexandre Bounine <alexandre.bounine@xxxxxxx>
Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
Cc: Aurelien Jacquiot <a-jacquiot@xxxxxx>
Cc: Andre van Herk <andre.van.herk@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
---
drivers/net/rionet.c | 152 +++++++++++++++++++++++++++++++++----------------
1 files changed, 102 insertions(+), 50 deletions(-)

diff --git a/drivers/net/rionet.c b/drivers/net/rionet.c
index f994fa1..c15d958 100644
--- a/drivers/net/rionet.c
+++ b/drivers/net/rionet.c
@@ -63,6 +63,7 @@ struct rionet_private {
spinlock_t lock;
spinlock_t tx_lock;
u32 msg_enable;
+ bool open;
};

struct rionet_peer {
@@ -74,6 +75,7 @@ struct rionet_peer {
struct rionet_net {
struct net_device *ndev;
struct list_head peers;
+ spinlock_t lock; /* net info access lock */
struct rio_dev **active;
int nact; /* number of active peers */
};
@@ -235,26 +237,32 @@ static void rionet_dbell_event(struct rio_mport *mport, void *dev_id, u16 sid, u
struct net_device *ndev = dev_id;
struct rionet_private *rnet = netdev_priv(ndev);
struct rionet_peer *peer;
+ unsigned char netid = rnet->mport->id;

if (netif_msg_intr(rnet))
printk(KERN_INFO "%s: doorbell sid %4.4x tid %4.4x info %4.4x",
DRV_NAME, sid, tid, info);
if (info == RIONET_DOORBELL_JOIN) {
- if (!nets[rnet->mport->id].active[sid]) {
- list_for_each_entry(peer,
- &nets[rnet->mport->id].peers, node) {
+ if (!nets[netid].active[sid]) {
+ spin_lock(&nets[netid].lock);
+ list_for_each_entry(peer, &nets[netid].peers, node) {
if (peer->rdev->destid == sid) {
- nets[rnet->mport->id].active[sid] =
- peer->rdev;
- nets[rnet->mport->id].nact++;
+ nets[netid].active[sid] = peer->rdev;
+ nets[netid].nact++;
}
}
+ spin_unlock(&nets[netid].lock);
+
rio_mport_send_doorbell(mport, sid,
RIONET_DOORBELL_JOIN);
}
} else if (info == RIONET_DOORBELL_LEAVE) {
- nets[rnet->mport->id].active[sid] = NULL;
- nets[rnet->mport->id].nact--;
+ spin_lock(&nets[netid].lock);
+ if (nets[netid].active[sid]) {
+ nets[netid].active[sid] = NULL;
+ nets[netid].nact--;
+ }
+ spin_unlock(&nets[netid].lock);
} else {
if (netif_msg_intr(rnet))
printk(KERN_WARNING "%s: unhandled doorbell\n",
@@ -308,8 +316,10 @@ static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbo
static int rionet_open(struct net_device *ndev)
{
int i, rc = 0;
- struct rionet_peer *peer, *tmp;
+ struct rionet_peer *peer;
struct rionet_private *rnet = netdev_priv(ndev);
+ unsigned char netid = rnet->mport->id;
+ unsigned long flags;

if (netif_msg_ifup(rnet))
printk(KERN_INFO "%s: open\n", DRV_NAME);
@@ -348,20 +358,13 @@ static int rionet_open(struct net_device *ndev)
netif_carrier_on(ndev);
netif_start_queue(ndev);

- list_for_each_entry_safe(peer, tmp,
- &nets[rnet->mport->id].peers, node) {
- if (!(peer->res = rio_request_outb_dbell(peer->rdev,
- RIONET_DOORBELL_JOIN,
- RIONET_DOORBELL_LEAVE)))
- {
- printk(KERN_ERR "%s: error requesting doorbells\n",
- DRV_NAME);
- continue;
- }
-
+ spin_lock_irqsave(&nets[netid].lock, flags);
+ list_for_each_entry(peer, &nets[netid].peers, node) {
/* Send a join message */
rio_send_doorbell(peer->rdev, RIONET_DOORBELL_JOIN);
}
+ spin_unlock_irqrestore(&nets[netid].lock, flags);
+ rnet->open = true;

out:
return rc;
@@ -370,7 +373,9 @@ static int rionet_open(struct net_device *ndev)
static int rionet_close(struct net_device *ndev)
{
struct rionet_private *rnet = netdev_priv(ndev);
- struct rionet_peer *peer, *tmp;
+ struct rionet_peer *peer;
+ unsigned char netid = rnet->mport->id;
+ unsigned long flags;
int i;

if (netif_msg_ifup(rnet))
@@ -378,18 +383,21 @@ static int rionet_close(struct net_device *ndev)

netif_stop_queue(ndev);
netif_carrier_off(ndev);
+ rnet->open = false;

for (i = 0; i < RIONET_RX_RING_SIZE; i++)
kfree_skb(rnet->rx_skb[i]);

- list_for_each_entry_safe(peer, tmp,
- &nets[rnet->mport->id].peers, node) {
- if (nets[rnet->mport->id].active[peer->rdev->destid]) {
+ spin_lock_irqsave(&nets[netid].lock, flags);
+ list_for_each_entry(peer, &nets[netid].peers, node) {
+ if (nets[netid].active[peer->rdev->destid]) {
rio_send_doorbell(peer->rdev, RIONET_DOORBELL_LEAVE);
- nets[rnet->mport->id].active[peer->rdev->destid] = NULL;
+ nets[netid].active[peer->rdev->destid] = NULL;
}
- rio_release_outb_dbell(peer->rdev, peer->res);
+ if (peer->res)
+ rio_release_outb_dbell(peer->rdev, peer->res);
}
+ spin_unlock_irqrestore(&nets[netid].lock, flags);

rio_release_inb_dbell(rnet->mport, RIONET_DOORBELL_JOIN,
RIONET_DOORBELL_LEAVE);
@@ -403,22 +411,38 @@ static void rionet_remove_dev(struct device *dev, struct subsys_interface *sif)
{
struct rio_dev *rdev = to_rio_dev(dev);
unsigned char netid = rdev->net->hport->id;
- struct rionet_peer *peer, *tmp;
+ struct rionet_peer *peer;
+ int state, found = 0;
+ unsigned long flags;

- if (dev_rionet_capable(rdev)) {
- list_for_each_entry_safe(peer, tmp, &nets[netid].peers, node) {
- if (peer->rdev == rdev) {
- if (nets[netid].active[rdev->destid]) {
- nets[netid].active[rdev->destid] = NULL;
- nets[netid].nact--;
+ if (!dev_rionet_capable(rdev))
+ return;
+
+ spin_lock_irqsave(&nets[netid].lock, flags);
+ list_for_each_entry(peer, &nets[netid].peers, node) {
+ if (peer->rdev == rdev) {
+ list_del(&peer->node);
+ if (nets[netid].active[rdev->destid]) {
+ state = atomic_read(&rdev->state);
+ if (state != RIO_DEVICE_GONE &&
+ state != RIO_DEVICE_INITIALIZING) {
+ rio_send_doorbell(rdev,
+ RIONET_DOORBELL_LEAVE);
}
-
- list_del(&peer->node);
- kfree(peer);
- break;
+ nets[netid].active[rdev->destid] = NULL;
+ nets[netid].nact--;
}
+ found = 1;
+ break;
}
}
+ spin_unlock_irqrestore(&nets[netid].lock, flags);
+
+ if (found) {
+ if (peer->res)
+ rio_release_outb_dbell(rdev, peer->res);
+ kfree(peer);
+ }
}

static void rionet_get_drvinfo(struct net_device *ndev,
@@ -492,6 +516,7 @@ static int rionet_setup_netdev(struct rio_mport *mport, struct net_device *ndev)
/* Set up private area */
rnet = netdev_priv(ndev);
rnet->mport = mport;
+ rnet->open = false;

/* Set the default MAC address */
device_id = rio_local_get_device_id(mport);
@@ -514,8 +539,11 @@ static int rionet_setup_netdev(struct rio_mport *mport, struct net_device *ndev)
rnet->msg_enable = RIONET_DEFAULT_MSGLEVEL;

rc = register_netdev(ndev);
- if (rc != 0)
+ if (rc != 0) {
+ free_pages((unsigned long)nets[mport->id].active,
+ get_order(rionet_active_bytes));
goto out;
+ }

printk(KERN_INFO "%s: %s %s Version %s, MAC %pM, %s\n",
ndev->name,
@@ -529,8 +557,6 @@ static int rionet_setup_netdev(struct rio_mport *mport, struct net_device *ndev)
return rc;
}

-static unsigned long net_table[RIONET_MAX_NETS/sizeof(unsigned long) + 1];
-
static int rionet_add_dev(struct device *dev, struct subsys_interface *sif)
{
int rc = -ENODEV;
@@ -539,19 +565,16 @@ static int rionet_add_dev(struct device *dev, struct subsys_interface *sif)
struct net_device *ndev = NULL;
struct rio_dev *rdev = to_rio_dev(dev);
unsigned char netid = rdev->net->hport->id;
- int oldnet;

if (netid >= RIONET_MAX_NETS)
return rc;

- oldnet = test_and_set_bit(netid, net_table);
-
/*
* If first time through this net, make sure local device is rionet
* capable and setup netdev (this step will be skipped in later probes
* on the same net).
*/
- if (!oldnet) {
+ if (!nets[netid].ndev) {
rio_local_read_config_32(rdev->net->hport, RIO_SRC_OPS_CAR,
&lsrc_ops);
rio_local_read_config_32(rdev->net->hport, RIO_DST_OPS_CAR,
@@ -569,30 +592,56 @@ static int rionet_add_dev(struct device *dev, struct subsys_interface *sif)
rc = -ENOMEM;
goto out;
}
- nets[netid].ndev = ndev;
+
rc = rionet_setup_netdev(rdev->net->hport, ndev);
if (rc) {
printk(KERN_ERR "%s: failed to setup netdev (rc=%d)\n",
DRV_NAME, rc);
+ free_netdev(ndev);
goto out;
}

INIT_LIST_HEAD(&nets[netid].peers);
+ spin_lock_init(&nets[netid].lock);
nets[netid].nact = 0;
- } else if (nets[netid].ndev == NULL)
- goto out;
+ nets[netid].ndev = ndev;
+ }

/*
* If the remote device has mailbox/doorbell capabilities,
* add it to the peer list.
*/
if (dev_rionet_capable(rdev)) {
- if (!(peer = kmalloc(sizeof(struct rionet_peer), GFP_KERNEL))) {
+ struct rionet_private *rnet;
+ unsigned long flags;
+
+ rnet = netdev_priv(nets[netid].ndev);
+
+ peer = kzalloc(sizeof(*peer), GFP_KERNEL);
+ if (!peer) {
rc = -ENOMEM;
goto out;
}
peer->rdev = rdev;
+ peer->res = rio_request_outb_dbell(peer->rdev,
+ RIONET_DOORBELL_JOIN,
+ RIONET_DOORBELL_LEAVE);
+ if (!peer->res) {
+ pr_err("%s: error requesting doorbells\n", DRV_NAME);
+ kfree(peer);
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ spin_lock_irqsave(&nets[netid].lock, flags);
list_add_tail(&peer->node, &nets[netid].peers);
+ spin_unlock_irqrestore(&nets[netid].lock, flags);
+ pr_debug("%s: %s add peer %s\n",
+ DRV_NAME, __func__, rio_name(rdev));
+
+ /* If netdev is already opened, send join request to new peer */
+ if (rnet->open)
+ rio_send_doorbell(peer->rdev, RIONET_DOORBELL_JOIN);
}

return 0;
@@ -603,7 +652,8 @@ out:
static int rionet_shutdown(struct notifier_block *nb, unsigned long code,
void *unused)
{
- struct rionet_peer *peer, *tmp;
+ struct rionet_peer *peer;
+ unsigned long flags;
int i;

pr_debug("%s: %s\n", DRV_NAME, __func__);
@@ -612,13 +662,15 @@ static int rionet_shutdown(struct notifier_block *nb, unsigned long code,
if (!nets[i].ndev)
continue;

- list_for_each_entry_safe(peer, tmp, &nets[i].peers, node) {
+ spin_lock_irqsave(&nets[i].lock, flags);
+ list_for_each_entry(peer, &nets[i].peers, node) {
if (nets[i].active[peer->rdev->destid]) {
rio_send_doorbell(peer->rdev,
RIONET_DOORBELL_LEAVE);
nets[i].active[peer->rdev->destid] = NULL;
}
}
+ spin_unlock_irqrestore(&nets[i].lock, flags);
}

return NOTIFY_DONE;
--
1.7.8.4

Next message: David Daney: "[PATCH v5 0/3] Add host controller drivers for Cavium ThunderX PCI"
Previous message: Alexey Khoroshilov: "[PATCH] mmc: mmc_spi: add checks for dma mapping error"
In reply to: Alexandre Bounine: "[PATCH 27/30] rapidio/tsi721_dma: update error reporting from prep_sg callback"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]