| Message ID | 20170217100233.2325-2-jszhang@marvell.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
Hi Jisheng, On ven., févr. 17 2017, Jisheng Zhang <jszhang@marvell.com> wrote: > In hot code path mvneta_rx_hwbm(), the rx_desc->status is read twice. > The rx_desc is allocated by dma_alloc_coherent, it's uncacheable if > the device isn't cache-coherent, reading from uncached memory is > fairly slow. So reuse the read out rx_status to avoid the second > reading from uncached memory. > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com> > Suggested-by: Arnd Bergmann <arnd@arndb.de> This one is OK and I didn't see a regression: Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Gregory > --- > drivers/net/ethernet/marvell/mvneta.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c > index 61dd4462411c..06df72b8da85 100644 > --- a/drivers/net/ethernet/marvell/mvneta.c > +++ b/drivers/net/ethernet/marvell/mvneta.c > @@ -313,8 +313,8 @@ > ((addr >= txq->tso_hdrs_phys) && \ > (addr < txq->tso_hdrs_phys + txq->size * TSO_HEADER_SIZE)) > > -#define MVNETA_RX_GET_BM_POOL_ID(rxd) \ > - (((rxd)->status & MVNETA_RXD_BM_POOL_MASK) >> MVNETA_RXD_BM_POOL_SHIFT) > +#define MVNETA_RX_GET_BM_POOL_ID(status) \ > + (((status) & MVNETA_RXD_BM_POOL_MASK) >> MVNETA_RXD_BM_POOL_SHIFT) > > struct mvneta_statistic { > unsigned short offset; > @@ -1900,7 +1900,7 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp, > for (i = 0; i < rx_done; i++) { > struct mvneta_rx_desc *rx_desc = > mvneta_rxq_next_desc_get(rxq); > - u8 pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc); > + u8 pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc->status); > struct mvneta_bm_pool *bm_pool; > > bm_pool = &pp->bm_priv->bm_pools[pool_id]; > @@ -2075,7 +2075,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int rx_todo, > rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE); > data = (u8 *)(uintptr_t)rx_desc->buf_cookie; > phys_addr = rx_desc->buf_phys_addr; > - pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc); > + pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_status); > bm_pool = &pp->bm_priv->bm_pools[pool_id]; > > if (!mvneta_rxq_desc_is_first_last(rx_status) || > -- > 2.11.0 >
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 61dd4462411c..06df72b8da85 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -313,8 +313,8 @@ ((addr >= txq->tso_hdrs_phys) && \ (addr < txq->tso_hdrs_phys + txq->size * TSO_HEADER_SIZE)) -#define MVNETA_RX_GET_BM_POOL_ID(rxd) \ - (((rxd)->status & MVNETA_RXD_BM_POOL_MASK) >> MVNETA_RXD_BM_POOL_SHIFT) +#define MVNETA_RX_GET_BM_POOL_ID(status) \ + (((status) & MVNETA_RXD_BM_POOL_MASK) >> MVNETA_RXD_BM_POOL_SHIFT) struct mvneta_statistic { unsigned short offset; @@ -1900,7 +1900,7 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp, for (i = 0; i < rx_done; i++) { struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq); - u8 pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc); + u8 pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc->status); struct mvneta_bm_pool *bm_pool; bm_pool = &pp->bm_priv->bm_pools[pool_id]; @@ -2075,7 +2075,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int rx_todo, rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE); data = (u8 *)(uintptr_t)rx_desc->buf_cookie; phys_addr = rx_desc->buf_phys_addr; - pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc); + pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_status); bm_pool = &pp->bm_priv->bm_pools[pool_id]; if (!mvneta_rxq_desc_is_first_last(rx_status) ||
In hot code path mvneta_rx_hwbm(), the rx_desc->status is read twice. The rx_desc is allocated by dma_alloc_coherent, it's uncacheable if the device isn't cache-coherent, reading from uncached memory is fairly slow. So reuse the read out rx_status to avoid the second reading from uncached memory. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Suggested-by: Arnd Bergmann <arnd@arndb.de> --- drivers/net/ethernet/marvell/mvneta.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)