sfc: Move all TX DMA length limiting into tx.c
Replace the duplicated logic in efx_enqueue_skb() and
efx_tx_queue_insert() with an inline function, efx_max_tx_len().
Remove the failed attempt at abstracting hardware-specifics and put
all the magic numbers in efx_max_tx_len().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c
index ae554ee..303919a 100644
--- a/drivers/net/sfc/tx.c
+++ b/drivers/net/sfc/tx.c
@@ -124,6 +124,24 @@
}
+static inline unsigned
+efx_max_tx_len(struct efx_nic *efx, dma_addr_t dma_addr)
+{
+ /* Depending on the NIC revision, we can use descriptor
+ * lengths up to 8K or 8K-1. However, since PCI Express
+ * devices must split read requests at 4K boundaries, there is
+ * little benefit from using descriptors that cross those
+ * boundaries and we keep things simple by not doing so.
+ */
+ unsigned len = (~dma_addr & 0xfff) + 1;
+
+ /* Work around hardware bug for unaligned buffers. */
+ if (EFX_WORKAROUND_5391(efx) && (dma_addr & 0xf))
+ len = min_t(unsigned, len, 512 - (dma_addr & 0xf));
+
+ return len;
+}
+
/*
* Add a socket buffer to a TX queue
*
@@ -146,7 +164,7 @@
skb_frag_t *fragment;
struct page *page;
int page_offset;
- unsigned int len, unmap_len = 0, fill_level, insert_ptr, misalign;
+ unsigned int len, unmap_len = 0, fill_level, insert_ptr;
dma_addr_t dma_addr, unmap_addr = 0;
unsigned int dma_len;
bool unmap_single;
@@ -223,14 +241,10 @@
EFX_BUG_ON_PARANOID(!buffer->continuation);
EFX_BUG_ON_PARANOID(buffer->unmap_len);
- dma_len = (((~dma_addr) & efx->type->tx_dma_mask) + 1);
- if (likely(dma_len > len))
+ dma_len = efx_max_tx_len(efx, dma_addr);
+ if (likely(dma_len >= len))
dma_len = len;
- misalign = (unsigned)dma_addr & efx->type->bug5391_mask;
- if (misalign && dma_len + misalign > 512)
- dma_len = 512 - misalign;
-
/* Fill out per descriptor fields */
buffer->len = dma_len;
buffer->dma_addr = dma_addr;
@@ -703,7 +717,7 @@
{
struct efx_tx_buffer *buffer;
struct efx_nic *efx = tx_queue->efx;
- unsigned dma_len, fill_level, insert_ptr, misalign;
+ unsigned dma_len, fill_level, insert_ptr;
int q_space;
EFX_BUG_ON_PARANOID(len <= 0);
@@ -752,12 +766,7 @@
buffer->dma_addr = dma_addr;
- /* Ensure we do not cross a boundary unsupported by H/W */
- dma_len = (~dma_addr & efx->type->tx_dma_mask) + 1;
-
- misalign = (unsigned)dma_addr & efx->type->bug5391_mask;
- if (misalign && dma_len + misalign > 512)
- dma_len = 512 - misalign;
+ dma_len = efx_max_tx_len(efx, dma_addr);
/* If there is enough space to send then do so */
if (dma_len >= len)