@@ -563,63 +563,29 @@ static bool ice_can_reuse_rx_page(struct ice_rx_buf *rx_buf)
}
/**
- * ice_add_rx_frag - Add contents of Rx buffer to sk_buff
+ * ice_add_rx_frag - Add contents of Rx buffer to sk_buff as a frag
* @rx_buf: buffer containing page to add
- * @skb: sk_buf to place the data into
- * @size: the length of the packet
+ * @skb: sk_buff to place the data into
+ * @size: packet length from rx_desc
*
* This function will add the data contained in rx_buf->page to the skb.
- * This is done either through a direct copy if the data in the buffer is
- * less than the skb header size, otherwise it will just attach the page as
- * a frag to the skb.
- *
- * The function will then update the page offset
+ * It will just attach the page as a frag to the skb.
+ * The function will then update the page offset.
*/
static void
ice_add_rx_frag(struct ice_rx_buf *rx_buf, struct sk_buff *skb,
unsigned int size)
{
-#if (PAGE_SIZE < 8192)
- unsigned int truesize = ICE_RXBUF_2048;
+#if (PAGE_SIZE >= 8192)
+ unsigned int truesize = SKB_DATA_ALIGN(size);
#else
- unsigned int truesize = ALIGN(size, L1_CACHE_BYTES);
-#endif /* PAGE_SIZE < 8192) */
- struct page *page = rx_buf->page;
- unsigned int pull_len;
- unsigned char *va;
-
- va = page_address(page) + rx_buf->page_offset;
- if (unlikely(skb_is_nonlinear(skb)))
- goto add_tail_frag;
-
- /* will the data fit in the skb we allocated? if so, just
- * copy it as it is pretty small anyway
- */
- if (size <= ICE_RX_HDR_SIZE) {
- memcpy(__skb_put(skb, size), va, ALIGN(size, sizeof(long)));
-
- rx_buf->pagecnt_bias++;
- return;
- }
-
- /* we need the header to contain the greater of either ETH_HLEN or
- * 60 bytes if the skb->len is less than 60 for skb_pad.
- */
- pull_len = eth_get_headlen(va, ICE_RX_HDR_SIZE);
-
- /* align pull length to size of long to optimize memcpy performance */
- memcpy(__skb_put(skb, pull_len), va, ALIGN(pull_len, sizeof(long)));
+ unsigned int truesize = ICE_RXBUF_2048;
+#endif
- /* the header from the frame that we're adding as a frag was added to
- * linear part of skb so move the pointer past that header and
- * reduce the size of data
- */
- va += pull_len;
- size -= pull_len;
+ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buf->page,
+ rx_buf->page_offset, size, truesize);
-add_tail_frag:
- skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
- (unsigned long)va & ~PAGE_MASK, size, truesize);
+ /* page is being used so we must update the page offset */
ice_rx_buf_adjust_pg_offset(rx_buf, truesize);
}
@@ -642,25 +608,34 @@ ice_reuse_rx_page(struct ice_ring *rx_ring, struct ice_rx_buf *old_buf)
nta++;
rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
- /* transfer page from old buffer to new buffer */
- *new_buf = *old_buf;
+ /* Transfer page from old buffer to new buffer.
+ * Move each member individually to avoid possible store
+ * forwarding stalls and unnecessary copy of skb.
+ */
+ new_buf->dma = old_buf->dma;
+ new_buf->page = old_buf->page;
+ new_buf->page_offset = old_buf->page_offset;
+ new_buf->pagecnt_bias = old_buf->pagecnt_bias;
}
/**
* ice_get_rx_buf - Fetch Rx buffer and synchronize data for use
* @rx_ring: Rx descriptor ring to transact packets on
+ * @skb: skb to be used
* @size: size of buffer to add to skb
*
* This function will pull an Rx buffer from the ring and synchronize it
* for use by the CPU.
*/
static struct ice_rx_buf *
-ice_get_rx_buf(struct ice_ring *rx_ring, const unsigned int size)
+ice_get_rx_buf(struct ice_ring *rx_ring, struct sk_buff **skb,
+ const unsigned int size)
{
struct ice_rx_buf *rx_buf;
rx_buf = &rx_ring->rx_buf[rx_ring->next_to_clean];
prefetchw(rx_buf->page);
+ *skb = rx_buf->skb;
/* we are reusing so sync this buffer for CPU use */
dma_sync_single_range_for_cpu(rx_ring->dev, rx_buf->dma,
@@ -674,50 +649,64 @@ ice_get_rx_buf(struct ice_ring *rx_ring, const unsigned int size)
}
/**
- * ice_fetch_rx_buf - Allocate skb and populate it
+ * ice_construct_skb - Allocate skb and populate it
* @rx_ring: Rx descriptor ring to transact packets on
* @rx_buf: Rx buffer to pull data from
* @size: the length of the packet
*
- * This function allocates an skb on the fly, and populates it with the page
- * data from the current receive descriptor, taking care to set up the skb
- * correctly, as well as handling calling the page recycle function if
- * necessary.
+ * This function allocates an skb. It then populates it with the page
+ * data from the current receive descriptor, taking care to set up the
+ * skb correctly.
*/
static struct sk_buff *
-ice_fetch_rx_buf(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf,
- unsigned int size)
+ice_construct_skb(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf,
+ unsigned int size)
{
- struct sk_buff *skb = rx_buf->skb;
-
- if (likely(!skb)) {
- u8 *page_addr = page_address(rx_buf->page) +
- rx_buf->page_offset;
+ void *va = page_address(rx_buf->page) + rx_buf->page_offset;
+ unsigned int headlen;
+ struct sk_buff *skb;
- /* prefetch first cache line of first page */
- prefetch(page_addr);
+ /* prefetch first cache line of first page */
+ prefetch(va);
#if L1_CACHE_BYTES < 128
- prefetch((void *)(page_addr + L1_CACHE_BYTES));
+ prefetch((u8 *)va + L1_CACHE_BYTES);
#endif /* L1_CACHE_BYTES */
- /* allocate a skb to store the frags */
- skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
- ICE_RX_HDR_SIZE,
- GFP_ATOMIC | __GFP_NOWARN);
- if (unlikely(!skb)) {
- rx_ring->rx_stats.alloc_buf_failed++;
- rx_buf->pagecnt_bias++;
- return NULL;
- }
+ /* allocate a skb to store the frags */
+ skb = __napi_alloc_skb(&rx_ring->q_vector->napi, ICE_RX_HDR_SIZE,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(!skb))
+ return NULL;
+
+ skb_record_rx_queue(skb, rx_ring->q_index);
+ /* Determine available headroom for copy */
+ headlen = size;
+ if (headlen > ICE_RX_HDR_SIZE)
+ headlen = eth_get_headlen(va, ICE_RX_HDR_SIZE);
- skb_record_rx_queue(skb, rx_ring->q_index);
+ /* align pull length to size of long to optimize memcpy performance */
+ memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long)));
+
+ /* if we exhaust the linear part then add what is left as a frag */
+ size -= headlen;
+ if (size) {
+#if (PAGE_SIZE >= 8192)
+ unsigned int truesize = SKB_DATA_ALIGN(size);
+#else
+ unsigned int truesize = ICE_RXBUF_2048;
+#endif
+ skb_add_rx_frag(skb, 0, rx_buf->page,
+ rx_buf->page_offset + headlen, size, truesize);
+ /* buffer is used by skb, update page_offset */
+ ice_rx_buf_adjust_pg_offset(rx_buf, truesize);
} else {
- rx_buf->skb = NULL;
+ /* buffer is unused, reset bias back to rx_buf; data was copied
+ * onto skb's linear part so there's no need for adjusting
+ * page offset and we can reuse this buffer as-is
+ */
+ rx_buf->pagecnt_bias++;
}
- /* pull page into skb */
- ice_add_rx_frag(rx_buf, skb, size);
-
return skb;
}
@@ -744,6 +733,7 @@ static void ice_put_rx_buf(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf)
/* clear contents of buffer_info */
rx_buf->page = NULL;
+ rx_buf->skb = NULL;
}
/**
@@ -1024,11 +1014,19 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
size = le16_to_cpu(rx_desc->wb.pkt_len) &
ICE_RX_FLX_DESC_PKT_LEN_M;
- rx_buf = ice_get_rx_buf(rx_ring, size);
+ rx_buf = ice_get_rx_buf(rx_ring, &skb, size);
/* allocate (if needed) and populate skb */
- skb = ice_fetch_rx_buf(rx_ring, rx_buf, size);
- if (!skb)
+ if (skb)
+ ice_add_rx_frag(rx_buf, skb, size);
+ else
+ skb = ice_construct_skb(rx_ring, rx_buf, size);
+
+ /* exit if we failed to retrieve a buffer */
+ if (!skb) {
+ rx_ring->rx_stats.alloc_buf_failed++;
+ rx_buf->pagecnt_bias++;
break;
+ }
ice_put_rx_buf(rx_ring, rx_buf);
cleaned_count++;