sfc: Replace some literal constants with EFX_PAGE_SIZE/EFX_BUF_SIZE
The 'page size' for PCIe DMA, i.e. the alignment of boundaries at
which DMA must be broken, is 4KB. Name this value as EFX_PAGE_SIZE
and use it in efx_max_tx_len(). Redefine EFX_BUF_SIZE as
EFX_PAGE_SIZE since its value is also a result of that requirement,
and use it in efx_init_special_buffer().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index a43d1ca..dd50c4f 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -54,9 +54,6 @@
#define EFX_FLUSH_INTERVAL 10
#define EFX_FLUSH_POLL_COUNT 100
-/* Size and alignment of special buffers (4KB) */
-#define EFX_BUF_SIZE 4096
-
/* Depth of RX flush request fifo */
#define EFX_RX_FLUSH_COUNT 4
@@ -196,7 +193,7 @@
/* Write buffer descriptors to NIC */
for (i = 0; i < buffer->entries; i++) {
index = buffer->index + i;
- dma_addr = buffer->dma_addr + (i * 4096);
+ dma_addr = buffer->dma_addr + (i * EFX_BUF_SIZE);
netif_dbg(efx, probe, efx->net_dev,
"mapping special buffer %d at %llx\n",
index, (unsigned long long)dma_addr);
diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h
index 905a187..4f9d18a 100644
--- a/drivers/net/ethernet/sfc/nic.h
+++ b/drivers/net/ethernet/sfc/nic.h
@@ -65,6 +65,11 @@
#define FALCON_GMAC_LOOPBACKS \
(1 << LOOPBACK_GMAC)
+/* Alignment of PCIe DMA boundaries (4KB) */
+#define EFX_PAGE_SIZE 4096
+/* Size and alignment of buffer table entries (same) */
+#define EFX_BUF_SIZE EFX_PAGE_SIZE
+
/**
* struct falcon_board_type - board operations and type information
* @id: Board type id, as found in NVRAM
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 5cb81fa..a096e28 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -110,7 +110,7 @@
* little benefit from using descriptors that cross those
* boundaries and we keep things simple by not doing so.
*/
- unsigned len = (~dma_addr & 0xfff) + 1;
+ unsigned len = (~dma_addr & (EFX_PAGE_SIZE - 1)) + 1;
/* Work around hardware bug for unaligned buffers. */
if (EFX_WORKAROUND_5391(efx) && (dma_addr & 0xf))