From: Ben Hutchings <ben@decadent.org.uk>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org,
Chase Douglas <chase.douglas@canonical.com>,
Arne Nordmark <nordmark@mech.kth.se>
Subject: [PATCH net-next-2.6 2/2] 3c59x: Use fine-grained locks for MII and windowed register access
Date: Thu, 24 Jun 2010 00:55:41 +0100 [thread overview]
Message-ID: <1277337341.26161.18.camel@localhost> (raw)
In-Reply-To: <1277337161.26161.14.camel@localhost>
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>
Tested-by: Arne Nordmark <nordmark@mech.kth.se> [against 2.6.32]
---
drivers/net/3c59x.c | 66 ++++++++++++++++++++++++++++++---------------------
1 files changed, 39 insertions(+), 27 deletions(-)
diff --git a/drivers/net/3c59x.c b/drivers/net/3c59x.c
index beddef9..f4a3fb1 100644
--- a/drivers/net/3c59x.c
+++ b/drivers/net/3c59x.c
@@ -644,9 +644,15 @@ struct vortex_private {
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 void window_set(struct vortex_private *vp, int window)
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)
@@ -1784,7 +1798,6 @@ vortex_timer(unsigned long data)
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 +1818,7 @@ vortex_timer(unsigned long data)
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 +1837,8 @@ vortex_timer(unsigned long data)
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 +1867,8 @@ vortex_timer(unsigned long data)
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 +1876,6 @@ leave_media_alone:
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 +2064,11 @@ vortex_start_xmit(struct sk_buff *skb, struct net_device *dev)
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 +2240,7 @@ vortex_interrupt(int irq, void *dev_id)
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 +2301,8 @@ vortex_interrupt(int irq, void *dev_id)
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 +2824,22 @@ static void update_stats(void __iomem *ioaddr, struct net_device *dev)
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 +3062,8 @@ static int mdio_read(struct net_device *dev, int phy_id, int location)
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 +3087,9 @@ static int mdio_read(struct net_device *dev, int phy_id, int location)
4, Wn4_PhysicalMgmt);
mdio_delay(vp);
}
+
+ spin_unlock_bh(&vp->mii_lock);
+
return retval & 0x20000 ? 0xffff : retval>>1 & 0xffff;
}
@@ -3091,6 +3099,8 @@ static void mdio_write(struct net_device *dev, int phy_id, int location, int val
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 +3121,8 @@ static void mdio_write(struct net_device *dev, int phy_id, int location, int val
4, Wn4_PhysicalMgmt);
mdio_delay(vp);
}
+
+ spin_unlock_bh(&vp->mii_lock);
}
/* ACPI: Advanced Configuration and Power Interface. */
--
1.7.1
next prev parent reply other threads:[~2010-06-23 23:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-23 23:52 [PATCH net-next-2.6 0/2] 3c59x: Locking fixes Ben Hutchings
2010-06-23 23:54 ` [PATCH net-next-2.6 1/2] 3c59x: Specify window explicitly for access to windowed registers Ben Hutchings
2010-06-29 6:20 ` David Miller
2010-06-23 23:55 ` Ben Hutchings [this message]
2010-06-24 12:05 ` [PATCH net-next-2.6 2/2] 3c59x: Use fine-grained locks for MII and windowed register access Steffen Klassert
2010-06-24 12:57 ` Ben Hutchings
2010-06-24 14:00 ` Steffen Klassert
2010-06-25 0:45 ` Ben Hutchings
2010-06-25 8:24 ` Steffen Klassert
2010-06-29 6:18 ` David Miller
2010-06-29 6:39 ` Steffen Klassert
2010-06-30 1:26 ` [PATCHv2 net-next-2.6] " Ben Hutchings
2010-06-30 6:15 ` David Miller
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