From: Stephen Hemminger <shemminger@linux-foundation•org>
To: Jeff Garzik <jgarzik@pobox•com>
Cc: netdev@vger•kernel.org
Cc: Greg KH <greg@kroah•com>
Subject: [PATCH 09/17] sky2: memory barriers change
Date: Tue, 08 May 2007 20:49:58 -0700 [thread overview]
Message-ID: <20070509035029.621237655@linux-foundation.org> (raw)
In-Reply-To: 20070509034949.624934448@linux-foundation.org
[-- Attachment #1: sky2-more-mb.patch --]
[-- Type: text/plain, Size: 2059 bytes --]
Do some memory barrier changes for safety/perfomance:
Don't need read after update to index, mmiowb() followed by read at end
of irq is sufficient.
Signed-off-by: Stephn Hemminger <shemminger@linux-foundation•org>
---
drivers/net/sky2.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
--- sky2-2.6.21.orig/drivers/net/sky2.c 2007-05-08 10:29:09.000000000 -0700
+++ sky2-2.6.21/drivers/net/sky2.c 2007-05-08 10:29:14.000000000 -0700
@@ -836,10 +836,12 @@ static inline struct tx_ring_info *tx_le
/* Update chip's next pointer */
static inline void sky2_put_idx(struct sky2_hw *hw, unsigned q, u16 idx)
{
- q = Y2_QADDR(q, PREF_UNIT_PUT_IDX);
+ /* Make sure write' to descriptors are complete before we tell hardware */
wmb();
- sky2_write16(hw, q, idx);
- sky2_read16(hw, q);
+ sky2_write16(hw, Y2_QADDR(q, PREF_UNIT_PUT_IDX), idx);
+
+ /* Synchronize I/O on since next processor may write to tail */
+ mmiowb();
}
@@ -971,6 +973,7 @@ stopped:
/* reset the Rx prefetch unit */
sky2_write32(hw, Y2_QADDR(rxq, PREF_UNIT_CTRL), PREF_UNIT_RST_SET);
+ mmiowb();
}
/* Clean out receive buffer area, assumes receiver hardware stopped */
@@ -1190,7 +1193,7 @@ static int sky2_rx_start(struct sky2_por
}
/* Tell chip about available buffers */
- sky2_write16(hw, Y2_QADDR(rxq, PREF_UNIT_PUT_IDX), sky2->rx_put);
+ sky2_put_idx(hw, rxq, sky2->rx_put);
return 0;
nomem:
sky2_rx_clean(sky2);
@@ -1532,6 +1535,8 @@ static void sky2_tx_complete(struct sky2
}
sky2->tx_cons = idx;
+ smp_mb();
+
if (tx_avail(sky2) > MAX_SKB_TX_LE + 4)
netif_wake_queue(dev);
}
@@ -2210,6 +2215,7 @@ force_update:
/* Fully processed status ring so clear irq */
sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
+ mmiowb();
exit_loop:
if (buf_write[0]) {
@@ -2436,6 +2442,7 @@ static int sky2_poll(struct net_device *
if (work_done < work_limit) {
netif_rx_complete(dev0);
+ /* end of interrupt, re-enables also acts as I/O synchronization */
sky2_read32(hw, B0_Y2_SP_LISR);
return 0;
} else {
--
next prev parent reply other threads:[~2007-05-09 4:03 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-09 3:49 [PATCH 00/17] sky2 update for 2.6.22 Stephen Hemminger
2007-05-09 3:49 ` [PATCH 01/17] sky2: fix oops on shutdown Stephen Hemminger
2007-05-09 3:49 ` [PATCH 02/17] sky2: dont restrict config space access Stephen Hemminger
2007-05-09 3:49 ` [PATCH 03/17] sky2: keep track of receive alloc failures Stephen Hemminger
2007-05-09 3:49 ` [PATCH 04/17] sky2: remove dual port workaround Stephen Hemminger
2007-05-09 3:49 ` [PATCH 05/17] pci: advanced error reporting stub return values Stephen Hemminger
2007-05-10 15:48 ` Stephen Hemminger
2007-05-09 3:49 ` [PATCH 06/17] sky2: advanced error reporting Stephen Hemminger
2007-05-09 17:05 ` Linas Vepstas
2007-05-09 22:35 ` Stephen Hemminger
2007-05-09 3:49 ` [PATCH 07/17] sky2: use pci_config access functions Stephen Hemminger
2007-05-09 3:49 ` [PATCH 08/17] sky2: MIB counter overflow handling Stephen Hemminger
2007-05-09 3:49 ` Stephen Hemminger [this message]
2007-05-09 3:49 ` [PATCH 10/17] sky2: add prefetch for next skb on receive Stephen Hemminger
2007-05-09 3:50 ` [PATCH 11/17] sky2: use MII defines Stephen Hemminger
2007-05-09 3:50 ` [PATCH 12/17] sky2: chip id enum Stephen Hemminger
2007-05-09 3:50 ` [PATCH 13/17] sky2: whitespace cleanups Stephen Hemminger
2007-05-09 3:50 ` [PATCH 14/17] pci_wake_enabled function Stephen Hemminger
2007-05-09 3:50 ` [PATCH 15/17] sky2: only disable 88e8056 on some boards Stephen Hemminger
2007-05-09 3:50 ` [PATCH 16/17] sky2: make sure high DMA bits set Stephen Hemminger
2007-05-09 3:50 ` [PATCH 17/17] sky2: version 1.15 Stephen Hemminger
2007-05-09 4:16 ` [PATCH 00/17] sky2 update for 2.6.22 Jeff Garzik
2007-05-09 14:48 ` Stephen Hemminger
2007-05-09 23:27 ` Jeff Garzik
2007-05-10 5:08 ` Stephen Hemminger
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