sfc: Properly distinguish RX buffer and DMA lengths

Replace efx_nic::rx_buffer_len with efx_nic::rx_dma_len, the maximum
RX DMA length.

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

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 5e1ddc559b4f0c64d5c07de25e840a17a9fecdf9..34b56ec87fba57179e9498b59aeffcf2c0160e4d 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -639,12 +639,11 @@ static void efx_start_datapath(struct efx_nic *efx)
         * support the current MTU, including padding for header
         * alignment and overruns.
         */
-       efx->rx_buffer_len = (max(EFX_PAGE_IP_ALIGN, NET_IP_ALIGN) +
-                             EFX_MAX_FRAME_LEN(efx->net_dev->mtu) +
-                             efx->type->rx_buffer_hash_size +
-                             efx->type->rx_buffer_padding);
-       efx->rx_buffer_order = get_order(efx->rx_buffer_len +
-                                        sizeof(struct efx_rx_page_state));
+       efx->rx_dma_len = (efx->type->rx_buffer_hash_size +
+                          EFX_MAX_FRAME_LEN(efx->net_dev->mtu) +
+                          efx->type->rx_buffer_padding);
+       efx->rx_buffer_order = get_order(sizeof(struct efx_rx_page_state) +
+                                        EFX_PAGE_IP_ALIGN + efx->rx_dma_len);
 
        /* We must keep at least one descriptor in a TX ring empty.
         * We could avoid this when the queue size does not exactly

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index f74411fc000c51187bd81b68e77dca5217532b0c..fc6770e07d5a37da008630fd85049076d40d5c8d 100644 (file)
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -669,8 +669,7 @@ struct vfdi_status;
  * @n_channels: Number of channels in use
  * @n_rx_channels: Number of channels used for RX (= number of RX queues)
  * @n_tx_channels: Number of channels used for TX
- * @rx_buffer_len: RX buffer length, including start alignment but excluding
- *     any metadata
+ * @rx_dma_len: Current maximum RX DMA length
  * @rx_buffer_order: Order (log2) of number of pages for each RX buffer
  * @rx_hash_key: Toeplitz hash key for RSS
  * @rx_indir_table: Indirection table for RSS
@@ -786,7 +785,7 @@ struct efx_nic {
        unsigned rss_spread;
        unsigned tx_channel_offset;
        unsigned n_tx_channels;
-       unsigned int rx_buffer_len;
+       unsigned int rx_dma_len;
        unsigned int rx_buffer_order;
        u8 rx_hash_key[40];
        u32 rx_indir_table[128];

diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index e7aa28eb932783ffcf6d741d3feaaf65b6d04eec..31361db28f9129111ddc187ec82eb5978c026df5 100644 (file)
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -27,8 +27,9 @@
 /* Number of RX descriptors pushed at once. */
 #define EFX_RX_BATCH  8
 
-/* Maximum size of a buffer sharing a page */
-#define EFX_RX_HALF_PAGE ((PAGE_SIZE >> 1) - sizeof(struct efx_rx_page_state))
+/* Maximum length for an RX descriptor sharing a page */
+#define EFX_RX_HALF_PAGE ((PAGE_SIZE >> 1) - sizeof(struct efx_rx_page_state) \
+                         - EFX_PAGE_IP_ALIGN)
 
 /* Size of buffer allocated for skb header area. */
 #define EFX_SKB_HEADERS  64u
@@ -52,10 +53,6 @@ static inline unsigned int efx_rx_buf_offset(struct efx_nic *efx,
 {
        return buf->page_offset + efx->type->rx_buffer_hash_size;
 }
-static inline unsigned int efx_rx_buf_size(struct efx_nic *efx)
-{
-       return PAGE_SIZE << efx->rx_buffer_order;
-}
 
 static u8 *efx_rx_buf_eh(struct efx_nic *efx, struct efx_rx_buffer *buf)
 {
@@ -105,7 +102,7 @@ static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue)
                if (unlikely(page == NULL))
                        return -ENOMEM;
                dma_addr = dma_map_page(&efx->pci_dev->dev, page, 0,
-                                       efx_rx_buf_size(efx),
+                                       PAGE_SIZE << efx->rx_buffer_order,
                                        DMA_FROM_DEVICE);
                if (unlikely(dma_mapping_error(&efx->pci_dev->dev, dma_addr))) {
                        __free_pages(page, efx->rx_buffer_order);
@@ -124,12 +121,12 @@ static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue)
                rx_buf->dma_addr = dma_addr + EFX_PAGE_IP_ALIGN;
                rx_buf->page = page;
                rx_buf->page_offset = page_offset + EFX_PAGE_IP_ALIGN;
-               rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
+               rx_buf->len = efx->rx_dma_len;
                rx_buf->flags = 0;
                ++rx_queue->added_count;
                ++state->refcnt;
 
-               if ((~count & 1) && (efx->rx_buffer_len <= EFX_RX_HALF_PAGE)) {
+               if ((~count & 1) && (efx->rx_dma_len <= EFX_RX_HALF_PAGE)) {
                        /* Use the second half of the page */
                        get_page(page);
                        dma_addr += (PAGE_SIZE >> 1);
@@ -153,7 +150,7 @@ static void efx_unmap_rx_buffer(struct efx_nic *efx,
                if (--state->refcnt == 0) {
                        dma_unmap_page(&efx->pci_dev->dev,
                                       state->dma_addr,
-                                      efx_rx_buf_size(efx),
+                                      PAGE_SIZE << efx->rx_buffer_order,
                                       DMA_FROM_DEVICE);
                } else if (used_len) {
                        dma_sync_single_for_cpu(&efx->pci_dev->dev,
@@ -221,7 +218,7 @@ static void efx_recycle_rx_buffer(struct efx_channel *channel,
 
        rx_buf->flags = 0;
 
-       if (efx->rx_buffer_len <= EFX_RX_HALF_PAGE &&
+       if (efx->rx_dma_len <= EFX_RX_HALF_PAGE &&
            page_count(rx_buf->page) == 1)
                efx_resurrect_rx_buffer(rx_queue, rx_buf);