bnxt_en: Divide a page into 32K buffers for the aggregation ring if necessary.

Orabug: 23221795

If PAGE_SIZE is bigger than BNXT_RX_PAGE_SIZE, that means the native CPU
page is bigger than the maximum length of the RX BD.  Divide the page
into multiple 32K buffers for the aggregation ring.

Add an offset field in the bnxt_sw_rx_agg_bd struct to keep track of the
page offset of each buffer.  Since each page can be referenced by multiple
buffer entries, call get_page() as needed to get the proper reference
count.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 89d0a06c516339c0a2b3d02677f5d6310b3319fb)
Signed-off-by: Brian Maly <brian.maly@oracle.com>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 1784db4299fde1f1d34c9adcd7392fbe0d234c2f..59482568071102b0bcde5338a63971918dd07063 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -584,12 +584,30 @@ static inline int bnxt_alloc_rx_page(struct bnxt *bp,
        struct page *page;
        dma_addr_t mapping;
        u16 sw_prod = rxr->rx_sw_agg_prod;
+       unsigned int offset = 0;
 
-       page = alloc_page(gfp);
-       if (!page)
-               return -ENOMEM;
+       if (PAGE_SIZE > BNXT_RX_PAGE_SIZE) {
+               page = rxr->rx_page;
+               if (!page) {
+                       page = alloc_page(gfp);
+                       if (!page)
+                               return -ENOMEM;
+                       rxr->rx_page = page;
+                       rxr->rx_page_offset = 0;
+               }
+               offset = rxr->rx_page_offset;
+               rxr->rx_page_offset += BNXT_RX_PAGE_SIZE;
+               if (rxr->rx_page_offset == PAGE_SIZE)
+                       rxr->rx_page = NULL;
+               else
+                       get_page(page);
+       } else {
+               page = alloc_page(gfp);
+               if (!page)
+                       return -ENOMEM;
+       }
 
-       mapping = dma_map_page(&pdev->dev, page, 0, BNXT_RX_PAGE_SIZE,
+       mapping = dma_map_page(&pdev->dev, page, offset, BNXT_RX_PAGE_SIZE,
                               PCI_DMA_FROMDEVICE);
        if (dma_mapping_error(&pdev->dev, mapping)) {
                __free_page(page);
@@ -604,6 +622,7 @@ static inline int bnxt_alloc_rx_page(struct bnxt *bp,
        rxr->rx_sw_agg_prod = NEXT_RX_AGG(sw_prod);
 
        rx_agg_buf->page = page;
+       rx_agg_buf->offset = offset;
        rx_agg_buf->mapping = mapping;
        rxbd->rx_bd_haddr = cpu_to_le64(mapping);
        rxbd->rx_bd_opaque = sw_prod;
@@ -645,6 +664,7 @@ static void bnxt_reuse_rx_agg_bufs(struct bnxt_napi *bnapi, u16 cp_cons,
                page = cons_rx_buf->page;
                cons_rx_buf->page = NULL;
                prod_rx_buf->page = page;
+               prod_rx_buf->offset = cons_rx_buf->offset;
 
                prod_rx_buf->mapping = cons_rx_buf->mapping;
 
@@ -712,7 +732,8 @@ static struct sk_buff *bnxt_rx_pages(struct bnxt *bp, struct bnxt_napi *bnapi,
                            RX_AGG_CMP_LEN) >> RX_AGG_CMP_LEN_SHIFT;
 
                cons_rx_buf = &rxr->rx_agg_ring[cons];
-               skb_fill_page_desc(skb, i, cons_rx_buf->page, 0, frag_len);
+               skb_fill_page_desc(skb, i, cons_rx_buf->page,
+                                  cons_rx_buf->offset, frag_len);
                __clear_bit(cons, rxr->rx_agg_bmap);
 
                /* It is possible for bnxt_alloc_rx_page() to allocate
@@ -1594,6 +1615,10 @@ static void bnxt_free_rx_skbs(struct bnxt *bp)
 
                        __free_page(page);
                }
+               if (rxr->rx_page) {
+                       __free_page(rxr->rx_page);
+                       rxr->rx_page = NULL;
+               }
        }
 }
 

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 0cf1e2a73179f08f490111e1e78757376077df75..8b823ff558ffe2ab81422c0ce6bdfa61d3bc2b20 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -515,6 +515,7 @@ struct bnxt_sw_rx_bd {
 
 struct bnxt_sw_rx_agg_bd {
        struct page             *page;
+       unsigned int            offset;
        dma_addr_t              mapping;
 };
 
@@ -595,6 +596,9 @@ struct bnxt_rx_ring_info {
        unsigned long           *rx_agg_bmap;
        u16                     rx_agg_bmap_size;
 
+       struct page             *rx_page;
+       unsigned int            rx_page_offset;
+
        dma_addr_t              rx_desc_mapping[MAX_RX_PAGES];
        dma_addr_t              rx_agg_desc_mapping[MAX_RX_AGG_PAGES];