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| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-05-14 12:38:15 -0700 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-05-17 20:43:14 -0400 |
| commit | 50432cb534b566c4fd9e371fb37464a65ccd2391 (patch) | |
| tree | b9967313ebf46d37650fbbc66fb35240be1825c0 /drivers/net/sky2.c | |
| parent | 84787e3fc38a4847e5d75388d5a7fb3cf6bd7834 (diff) | |
| download | lwn-50432cb534b566c4fd9e371fb37464a65ccd2391.tar.gz lwn-50432cb534b566c4fd9e371fb37464a65ccd2391.zip | |
sky2: memory barriers change
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>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/net/sky2.c')
| -rw-r--r-- | drivers/net/sky2.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index ccbd8c2674b0..832fd69a0e59 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -844,10 +844,12 @@ static inline struct tx_ring_info *tx_le_re(struct sky2_port *sky2, /* 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(); } @@ -979,6 +981,7 @@ 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 */ @@ -1198,7 +1201,7 @@ static int sky2_rx_start(struct sky2_port *sky2) } /* 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); @@ -1540,6 +1543,8 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done) } sky2->tx_cons = idx; + smp_mb(); + if (tx_avail(sky2) > MAX_SKB_TX_LE + 4) netif_wake_queue(dev); } @@ -2218,6 +2223,7 @@ 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]) { @@ -2442,6 +2448,7 @@ static int sky2_poll(struct net_device *dev0, int *budget) 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 { |