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| author | Ben Hutchings <bhutchings@solarflare.com> | 2011-02-22 18:26:10 +0100 |
|---|---|---|
| committer | Ben Hutchings <bhutchings@solarflare.com> | 2011-03-04 18:58:42 +0100 |
| commit | 65f0b417dee94f779ce9b77102b7d73c93723b39 (patch) | |
| tree | 390279203a8c73a986d15be5cc30f9bb2e95c1e8 /drivers/net/sfc/efx.c | |
| parent | sfc: Bump version to 3.1 (diff) | |
| download | linux-65f0b417dee94f779ce9b77102b7d73c93723b39.tar.xz linux-65f0b417dee94f779ce9b77102b7d73c93723b39.zip | |
sfc: Use write-combining to reduce TX latency
Based on work by Neil Turton <nturton@solarflare.com> and
Kieran Mansley <kmansley@solarflare.com>.
The BIU has now been verified to handle 3- and 4-dword writes within a
single 128-bit register correctly. This means we can enable write-
combining and only insert write barriers between writes to distinct
registers.
This has been observed to save about 0.5 us when pushing a TX
descriptor to an empty TX queue.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Diffstat (limited to 'drivers/net/sfc/efx.c')
| -rw-r--r-- | drivers/net/sfc/efx.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c index d563049859a8..b8bd936374f2 100644 --- a/drivers/net/sfc/efx.c +++ b/drivers/net/sfc/efx.c @@ -1104,8 +1104,8 @@ static int efx_init_io(struct efx_nic *efx) rc = -EIO; goto fail3; } - efx->membase = ioremap_nocache(efx->membase_phys, - efx->type->mem_map_size); + efx->membase = ioremap_wc(efx->membase_phys, + efx->type->mem_map_size); if (!efx->membase) { netif_err(efx, probe, efx->net_dev, "could not map memory BAR at %llx+%x\n", |