sfc: Replace efx_rx_is_last_buffer() with a flag

This condition is brittle and we have lots of flags to spare.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

2 files changed, 7 insertions, 11 deletions

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 370c5bcebad9..e22e75c8f635 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -228,6 +228,7 @@ struct efx_rx_buffer {
         u16 len;
         u16 flags;
 };
+#define EFX_RX_BUF_LAST_IN_PAGE 0x0001
 #define EFX_RX_PKT_CSUMMED      0x0002
 #define EFX_RX_PKT_DISCARD      0x0004
 
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index eea56f3ec81c..4cc2ba48a912 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -95,14 +95,6 @@ static inline void efx_sync_rx_buffer(struct efx_nic *efx,
                                 DMA_FROM_DEVICE);
 }
 
-/* Return true if this is the last RX buffer using a page. */
-static inline bool efx_rx_is_last_buffer(struct efx_nic *efx,
-                                         struct efx_rx_buffer *rx_buf)
-{
-        return (rx_buf->page_offset >= (PAGE_SIZE >> 1) ||
-                efx->rx_dma_len > EFX_RX_HALF_PAGE);
-}
-
 /* Check the RX page recycle ring for a page that can be reused. */
 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
 {
@@ -199,11 +191,14 @@ static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue)
                 if ((~count & 1) && (efx->rx_dma_len <= EFX_RX_HALF_PAGE)) {
                         /* Use the second half of the page */
                         get_page(page);
+                        rx_buf->flags = 0;
                         dma_addr += (PAGE_SIZE >> 1);
                         page_offset += (PAGE_SIZE >> 1);
                         ++count;
                         goto split;
                 }
+
+                rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
         }
 
         return 0;
@@ -247,7 +242,7 @@ static void efx_recycle_rx_page(struct efx_channel *channel,
         unsigned index;
 
         /* Only recycle the page after processing the final buffer. */
-        if (!efx_rx_is_last_buffer(efx, rx_buf))
+        if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
                 return;
 
         index = rx_queue->page_add & rx_queue->page_ptr_mask;
@@ -278,7 +273,7 @@ static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
                 put_page(rx_buf->page);
 
         /* If this is the last buffer in a page, unmap and free it. */
-        if (efx_rx_is_last_buffer(rx_queue->efx, rx_buf)) {
+        if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
                 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
                 efx_free_rx_buffer(rx_buf);
         }
@@ -507,7 +502,7 @@ void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
         struct efx_rx_buffer *rx_buf;
 
         rx_buf = efx_rx_buffer(rx_queue, index);
-        rx_buf->flags = flags;
+        rx_buf->flags |= flags;
 
         /* Validate the number of fragments and completed length */
         if (n_frags == 1) {