From: Dave Jiang <dave.jiang@intel.com>
To: dan.j.williams@intel.com, linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org, davem@davemloft.net,
Dave Jiang <dave.jiang@intel.com>
Subject: [PATCH 3/3] netdma: adding alignment check for NETDMA ops
Date: Wed, 04 Apr 2012 16:10:46 -0700 [thread overview]
Message-ID: <20120404231046.20605.13918.stgit@djiang5-linux.ch.intel.com> (raw)
In-Reply-To: <20120404230749.20605.7000.stgit@djiang5-linux.ch.intel.com>
This is the fallout from adding memcpy alignment workaround for certain
IOATDMA hardware. NetDMA will only use DMA engine that can handle byte align
ops.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
drivers/dma/dmaengine.c | 14 ++++++++++++++
include/linux/dmaengine.h | 1 +
net/ipv4/tcp.c | 4 ++--
net/ipv4/tcp_input.c | 2 +-
net/ipv4/tcp_ipv4.c | 2 +-
net/ipv6/tcp_ipv6.c | 2 +-
6 files changed, 20 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index a6c6051..0f1ca74 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -332,6 +332,20 @@ struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
}
EXPORT_SYMBOL(dma_find_channel);
+/*
+ * net_dma_find_channel - find a channel for net_dma
+ * net_dma has alignment requirements
+ */
+struct dma_chan *net_dma_find_channel(void)
+{
+ struct dma_chan *chan = dma_find_channel(DMA_MEMCPY);
+ if (chan && !is_dma_copy_aligned(chan->device, 1, 1, 1))
+ return NULL;
+
+ return chan;
+}
+EXPORT_SYMBOL(net_dma_find_channel);
+
/**
* dma_issue_pending_all - flush all pending operations across all channels
*/
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 679b349..a5bb3ad 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -948,6 +948,7 @@ int dma_async_device_register(struct dma_device *device);
void dma_async_device_unregister(struct dma_device *device);
void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
+struct dma_chan *net_dma_find_channel(void);
#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
/* --- Helper iov-locking functions --- */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 22ef5f9..8712c5d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1450,7 +1450,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
if ((available < target) &&
(len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
!sysctl_tcp_low_latency &&
- dma_find_channel(DMA_MEMCPY)) {
+ net_dma_find_channel()) {
preempt_enable_no_resched();
tp->ucopy.pinned_list =
dma_pin_iovec_pages(msg->msg_iov, len);
@@ -1665,7 +1665,7 @@ do_prequeue:
if (!(flags & MSG_TRUNC)) {
#ifdef CONFIG_NET_DMA
if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
- tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
+ tp->ucopy.dma_chan = net_dma_find_channel();
if (tp->ucopy.dma_chan) {
tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b5e315f..27c676d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5190,7 +5190,7 @@ static int tcp_dma_try_early_copy(struct sock *sk, struct sk_buff *skb,
return 0;
if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
- tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
+ tp->ucopy.dma_chan = net_dma_find_channel();
if (tp->ucopy.dma_chan && skb_csum_unnecessary(skb)) {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index fd54c5f..3810b6f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1727,7 +1727,7 @@ process:
#ifdef CONFIG_NET_DMA
struct tcp_sock *tp = tcp_sk(sk);
if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
- tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
+ tp->ucopy.dma_chan = net_dma_find_channel();
if (tp->ucopy.dma_chan)
ret = tcp_v4_do_rcv(sk, skb);
else
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 3edd05a..fcb3e4f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1755,7 +1755,7 @@ process:
#ifdef CONFIG_NET_DMA
struct tcp_sock *tp = tcp_sk(sk);
if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
- tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
+ tp->ucopy.dma_chan = net_dma_find_channel();
if (tp->ucopy.dma_chan)
ret = tcp_v6_do_rcv(sk, skb);
else
next prev parent reply other threads:[~2012-04-04 23:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-04 23:10 [PATCH 0/3] Series short description Dave Jiang
2012-04-04 23:10 ` [PATCH 1/3] ioat: ring size variables need to be 32bit to avoid overflow Dave Jiang
2012-04-04 23:10 ` [PATCH 2/3] ioatdma: DMA copy alignment needed to address IOAT DMA silicon errata Dave Jiang
2012-04-04 23:10 ` Dave Jiang [this message]
2012-04-05 0:18 ` [PATCH 3/3] netdma: adding alignment check for NETDMA ops David Miller
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