From: Michael Ellerman <michael@ellerman.id.au>
To: <jgarzik@pobox.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linuxppc64-dev@ozlabs.org
Subject: [PATCH 6/18] iseries_veth: Replace lock-protected atomic with an ordinary variable
Date: Thu, 1 Sep 2005 11:29:06 +1000 (EST) [thread overview]
Message-ID: <20050901012906.9EF9568206@ozlabs.org> (raw)
In-Reply-To: <1125538127.859382.875909607846.qpush@concordia>
The iseries_veth driver uses atomic ops to manipulate the in_use field of
one of its per-connection structures. However all references to the
flag occur while the connection's lock is held, so the atomic ops aren't
necessary.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
drivers/net/iseries_veth.c | 13 +++++++------
1 files changed, 7 insertions(+), 6 deletions(-)
Index: veth-dev2/drivers/net/iseries_veth.c
===================================================================
--- veth-dev2.orig/drivers/net/iseries_veth.c
+++ veth-dev2/drivers/net/iseries_veth.c
@@ -117,7 +117,7 @@ struct veth_msg {
struct veth_msg *next;
struct VethFramesData data;
int token;
- unsigned long in_use;
+ int in_use;
struct sk_buff *skb;
struct device *dev;
};
@@ -957,6 +957,8 @@ static int veth_transmit_to_one(struct s
goto drop;
}
+ msg->in_use = 1;
+
dma_length = skb->len;
dma_address = dma_map_single(port->dev, skb->data,
dma_length, DMA_TO_DEVICE);
@@ -971,7 +973,6 @@ static int veth_transmit_to_one(struct s
msg->data.addr[0] = dma_address;
msg->data.len[0] = dma_length;
msg->data.eofmask = 1 << VETH_EOF_SHIFT;
- set_bit(0, &(msg->in_use));
rc = veth_signaldata(cnx, VethEventTypeFrames, msg->token, &msg->data);
if (rc != HvLpEvent_Rc_Good)
@@ -981,10 +982,8 @@ static int veth_transmit_to_one(struct s
return 0;
recycle_and_drop:
+ /* we free the skb below, so tell veth_recycle_msg() not to. */
msg->skb = NULL;
- /* need to set in use to make veth_recycle_msg in case this
- * was a mapping failure */
- set_bit(0, &msg->in_use);
veth_recycle_msg(cnx, msg);
drop:
port->stats.tx_errors++;
@@ -1066,12 +1065,14 @@ static int veth_start_xmit(struct sk_buf
return 0;
}
+/* You must hold the connection's lock when you call this function. */
static void veth_recycle_msg(struct veth_lpar_connection *cnx,
struct veth_msg *msg)
{
u32 dma_address, dma_length;
- if (test_and_clear_bit(0, &msg->in_use)) {
+ if (msg->in_use) {
+ msg->in_use = 0;
dma_address = msg->data.addr[0];
dma_length = msg->data.len[0];
next prev parent reply other threads:[~2005-09-01 1:29 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-01 1:28 [PATCH 0/18] Updates & bug fixes for iseries_veth network driver Michael Ellerman
2005-09-01 1:28 ` [PATCH 1/18] iseries_veth: Cleanup error and debug messages Michael Ellerman
2005-09-01 1:28 ` [PATCH 2/18] iseries_veth: Remove a FIXME WRT deletion of the ack_timer Michael Ellerman
2005-09-01 1:29 ` [PATCH 3/18] iseries_veth: Try to avoid pathological reset behaviour Michael Ellerman
2005-09-01 1:29 ` [PATCH 4/18] iseries_veth: Fix broken promiscuous handling Michael Ellerman
2005-09-01 1:29 ` [PATCH 5/18] iseries_veth: Remove redundant message stack lock Michael Ellerman
2005-09-01 1:29 ` Michael Ellerman [this message]
2005-09-01 1:29 ` [PATCH 7/18] iseries_veth: Only call dma_unmap_single() if dma_map_single() succeeded Michael Ellerman
2005-09-01 1:29 ` [PATCH 8/18] iseries_veth: Make init_connection() & destroy_connection() symmetrical Michael Ellerman
2005-09-01 1:29 ` [PATCH 9/18] iseries_veth: Use kobjects to track lifecycle of connection structs Michael Ellerman
2005-09-01 1:29 ` [PATCH 10/18] iseries_veth: Remove TX timeout code Michael Ellerman
2005-09-01 1:29 ` [PATCH 11/18] iseries_veth: Add a per-connection ack timer Michael Ellerman
2005-09-01 1:29 ` [PATCH 12/18] iseries_veth: Simplify full-queue handling Michael Ellerman
2005-09-01 1:29 ` [PATCH 13/18] iseries_veth: Fix bogus counting of TX errors Michael Ellerman
2005-09-01 1:29 ` [PATCH 14/18] iseries_veth: Add sysfs support for connection structs Michael Ellerman
2005-09-01 1:29 ` [PATCH 15/18] iseries_veth: Add sysfs support for port structs Michael Ellerman
2005-09-01 1:29 ` [PATCH 16/18] iseries_veth: Incorporate iseries_veth.h in iseries_veth.c Michael Ellerman
2005-09-01 1:29 ` [PATCH 17/18] iseries_veth: Remove studly caps from iseries_veth.c Michael Ellerman
2005-09-01 1:29 ` [PATCH 18/18] iseries_veth: Be consistent about driver name, increment version Michael Ellerman
2005-09-01 2:43 ` [PATCH 0/18] Updates & bug fixes for iseries_veth network driver Jeff Garzik
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