3c59x: Use fine-grained locks for MII and windowed register access
This avoids scheduling in atomic context and also means that IRQs
will only be deferred for relatively short periods of time.
Previously discussed in:
http://article.gmane.org/gmane.linux.network/155024
Reported-by: Arne Nordmark <nordmark@mech.kth.se>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/3c59x.c b/drivers/net/3c59x.c
index beddef9..069a03f 100644
--- a/drivers/net/3c59x.c
+++ b/drivers/net/3c59x.c
@@ -644,9 +644,15 @@
u16 deferred; /* Resend these interrupts when we
* bale from the ISR */
u16 io_size; /* Size of PCI region (for release_region) */
- spinlock_t lock; /* Serialise access to device & its vortex_private */
- struct mii_if_info mii; /* MII lib hooks/info */
- int window; /* Register window */
+
+ /* Serialises access to hardware other than MII and variables below.
+ * The lock hierarchy is rtnl_lock > lock > mii_lock > window_lock. */
+ spinlock_t lock;
+
+ spinlock_t mii_lock; /* Serialises access to MII */
+ struct mii_if_info mii; /* MII lib hooks/info */
+ spinlock_t window_lock; /* Serialises access to windowed regs */
+ int window; /* Register window */
};
static void window_set(struct vortex_private *vp, int window)
@@ -661,15 +667,23 @@
static u ## size \
window_read ## size(struct vortex_private *vp, int window, int addr) \
{ \
+ unsigned long flags; \
+ u ## size ret; \
+ spin_lock_irqsave(&vp->window_lock, flags); \
window_set(vp, window); \
- return ioread ## size(vp->ioaddr + addr); \
+ ret = ioread ## size(vp->ioaddr + addr); \
+ spin_unlock_irqrestore(&vp->window_lock, flags); \
+ return ret; \
} \
static void \
window_write ## size(struct vortex_private *vp, u ## size value, \
int window, int addr) \
{ \
+ unsigned long flags; \
+ spin_lock_irqsave(&vp->window_lock, flags); \
window_set(vp, window); \
iowrite ## size(value, vp->ioaddr + addr); \
+ spin_unlock_irqrestore(&vp->window_lock, flags); \
}
DEFINE_WINDOW_IO(8)
DEFINE_WINDOW_IO(16)
@@ -1181,6 +1195,8 @@
}
spin_lock_init(&vp->lock);
+ spin_lock_init(&vp->mii_lock);
+ spin_lock_init(&vp->window_lock);
vp->gendev = gendev;
vp->mii.dev = dev;
vp->mii.mdio_read = mdio_read;
@@ -1784,7 +1800,6 @@
pr_debug("dev->watchdog_timeo=%d\n", dev->watchdog_timeo);
}
- disable_irq_lockdep(dev->irq);
media_status = window_read16(vp, 4, Wn4_Media);
switch (dev->if_port) {
case XCVR_10baseT: case XCVR_100baseTx: case XCVR_100baseFx:
@@ -1805,10 +1820,7 @@
case XCVR_MII: case XCVR_NWAY:
{
ok = 1;
- /* Interrupts are already disabled */
- spin_lock(&vp->lock);
vortex_check_media(dev, 0);
- spin_unlock(&vp->lock);
}
break;
default: /* Other media types handled by Tx timeouts. */
@@ -1827,6 +1839,8 @@
if (!ok) {
unsigned int config;
+ spin_lock_irq(&vp->lock);
+
do {
dev->if_port = media_tbl[dev->if_port].next;
} while ( ! (vp->available_media & media_tbl[dev->if_port].mask));
@@ -1855,6 +1869,8 @@
if (vortex_debug > 1)
pr_debug("wrote 0x%08x to Wn3_Config\n", config);
/* AKPM: FIXME: Should reset Rx & Tx here. P60 of 3c90xc.pdf */
+
+ spin_unlock_irq(&vp->lock);
}
leave_media_alone:
@@ -1862,7 +1878,6 @@
pr_debug("%s: Media selection timer finished, %s.\n",
dev->name, media_tbl[dev->if_port].name);
- enable_irq_lockdep(dev->irq);
mod_timer(&vp->timer, RUN_AT(next_tick));
if (vp->deferred)
iowrite16(FakeIntr, ioaddr + EL3_CMD);
@@ -2051,9 +2066,11 @@
int len = (skb->len + 3) & ~3;
vp->tx_skb_dma = pci_map_single(VORTEX_PCI(vp), skb->data, len,
PCI_DMA_TODEVICE);
+ spin_lock_irq(&vp->window_lock);
window_set(vp, 7);
iowrite32(vp->tx_skb_dma, ioaddr + Wn7_MasterAddr);
iowrite16(len, ioaddr + Wn7_MasterLen);
+ spin_unlock_irq(&vp->window_lock);
vp->tx_skb = skb;
iowrite16(StartDMADown, ioaddr + EL3_CMD);
/* netif_wake_queue() will be called at the DMADone interrupt. */
@@ -2225,6 +2242,7 @@
pr_debug("%s: interrupt, status %4.4x, latency %d ticks.\n",
dev->name, status, ioread8(ioaddr + Timer));
+ spin_lock(&vp->window_lock);
window_set(vp, 7);
do {
@@ -2285,6 +2303,8 @@
iowrite16(AckIntr | IntReq | IntLatch, ioaddr + EL3_CMD);
} while ((status = ioread16(ioaddr + EL3_STATUS)) & (IntLatch | RxComplete));
+ spin_unlock(&vp->window_lock);
+
if (vortex_debug > 4)
pr_debug("%s: exiting interrupt, status %4.4x.\n",
dev->name, status);
@@ -2806,37 +2826,22 @@
static int vortex_nway_reset(struct net_device *dev)
{
struct vortex_private *vp = netdev_priv(dev);
- unsigned long flags;
- int rc;
- spin_lock_irqsave(&vp->lock, flags);
- rc = mii_nway_restart(&vp->mii);
- spin_unlock_irqrestore(&vp->lock, flags);
- return rc;
+ return mii_nway_restart(&vp->mii);
}
static int vortex_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
struct vortex_private *vp = netdev_priv(dev);
- unsigned long flags;
- int rc;
- spin_lock_irqsave(&vp->lock, flags);
- rc = mii_ethtool_gset(&vp->mii, cmd);
- spin_unlock_irqrestore(&vp->lock, flags);
- return rc;
+ return mii_ethtool_gset(&vp->mii, cmd);
}
static int vortex_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
struct vortex_private *vp = netdev_priv(dev);
- unsigned long flags;
- int rc;
- spin_lock_irqsave(&vp->lock, flags);
- rc = mii_ethtool_sset(&vp->mii, cmd);
- spin_unlock_irqrestore(&vp->lock, flags);
- return rc;
+ return mii_ethtool_sset(&vp->mii, cmd);
}
static u32 vortex_get_msglevel(struct net_device *dev)
@@ -3059,6 +3064,8 @@
int read_cmd = (0xf6 << 10) | (phy_id << 5) | location;
unsigned int retval = 0;
+ spin_lock_bh(&vp->mii_lock);
+
if (mii_preamble_required)
mdio_sync(vp, 32);
@@ -3082,6 +3089,9 @@
4, Wn4_PhysicalMgmt);
mdio_delay(vp);
}
+
+ spin_unlock_bh(&vp->mii_lock);
+
return retval & 0x20000 ? 0xffff : retval>>1 & 0xffff;
}
@@ -3091,6 +3101,8 @@
int write_cmd = 0x50020000 | (phy_id << 23) | (location << 18) | value;
int i;
+ spin_lock_bh(&vp->mii_lock);
+
if (mii_preamble_required)
mdio_sync(vp, 32);
@@ -3111,6 +3123,8 @@
4, Wn4_PhysicalMgmt);
mdio_delay(vp);
}
+
+ spin_unlock_bh(&vp->mii_lock);
}
/* ACPI: Advanced Configuration and Power Interface. */