diff options
| -rw-r--r-- | drivers/net/ethernet/sfc/io.h | 7 | ||||
| -rw-r--r-- | drivers/net/ethernet/sfc/tx.c | 22 |
2 files changed, 24 insertions, 5 deletions
diff --git a/drivers/net/ethernet/sfc/io.h b/drivers/net/ethernet/sfc/io.h index 4d3f119b67b3..afb94aa2c15e 100644 --- a/drivers/net/ethernet/sfc/io.h +++ b/drivers/net/ethernet/sfc/io.h @@ -66,10 +66,17 @@ #define EFX_USE_QWORD_IO 1 #endif +/* Hardware issue requires that only 64-bit naturally aligned writes + * are seen by hardware. Its not strictly necessary to restrict to + * x86_64 arch, but done for safety since unusual write combining behaviour + * can break PIO. + */ +#ifdef CONFIG_X86_64 /* PIO is a win only if write-combining is possible */ #ifdef ARCH_HAS_IOREMAP_WC #define EFX_USE_PIO 1 #endif +#endif #ifdef EFX_USE_QWORD_IO static inline void _efx_writeq(struct efx_nic *efx, __le64 value, diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index 75d11fa4eb0a..d79c842680a5 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -189,6 +189,18 @@ struct efx_short_copy_buffer { u8 buf[L1_CACHE_BYTES]; }; +/* Copy in explicit 64-bit writes. */ +static void efx_memcpy_64(void __iomem *dest, void *src, size_t len) +{ + u64 *src64 = src; + u64 __iomem *dest64 = dest; + size_t l64 = len / 8; + size_t i; + + for (i = 0; i < l64; i++) + writeq(src64[i], &dest64[i]); +} + /* Copy to PIO, respecting that writes to PIO buffers must be dword aligned. * Advances piobuf pointer. Leaves additional data in the copy buffer. */ @@ -198,7 +210,7 @@ static void efx_memcpy_toio_aligned(struct efx_nic *efx, u8 __iomem **piobuf, { int block_len = len & ~(sizeof(copy_buf->buf) - 1); - memcpy_toio(*piobuf, data, block_len); + efx_memcpy_64(*piobuf, data, block_len); *piobuf += block_len; len -= block_len; @@ -230,7 +242,7 @@ static void efx_memcpy_toio_aligned_cb(struct efx_nic *efx, u8 __iomem **piobuf, if (copy_buf->used < sizeof(copy_buf->buf)) return; - memcpy_toio(*piobuf, copy_buf->buf, sizeof(copy_buf->buf)); + efx_memcpy_64(*piobuf, copy_buf->buf, sizeof(copy_buf->buf)); *piobuf += sizeof(copy_buf->buf); data += copy_to_buf; len -= copy_to_buf; @@ -245,7 +257,7 @@ static void efx_flush_copy_buffer(struct efx_nic *efx, u8 __iomem *piobuf, { /* if there's anything in it, write the whole buffer, including junk */ if (copy_buf->used) - memcpy_toio(piobuf, copy_buf->buf, sizeof(copy_buf->buf)); + efx_memcpy_64(piobuf, copy_buf->buf, sizeof(copy_buf->buf)); } /* Traverse skb structure and copy fragments in to PIO buffer. @@ -304,8 +316,8 @@ efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue, struct sk_buff *skb) */ BUILD_BUG_ON(L1_CACHE_BYTES > SKB_DATA_ALIGN(sizeof(struct skb_shared_info))); - memcpy_toio(tx_queue->piobuf, skb->data, - ALIGN(skb->len, L1_CACHE_BYTES)); + efx_memcpy_64(tx_queue->piobuf, skb->data, + ALIGN(skb->len, L1_CACHE_BYTES)); } EFX_POPULATE_QWORD_5(buffer->option, |