mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-26 17:01:14 +00:00
68 lines
2.5 KiB
Diff
68 lines
2.5 KiB
Diff
|
From 2d7b6e7daf076b63f461ce9c4ec6022ddc3d15bb Mon Sep 17 00:00:00 2001
|
||
|
|
From: Camelia Groza <camelia.groza@nxp.com>
|
||
|
|
Date: Mon, 15 Jan 2018 17:42:42 +0200
|
||
|
|
Subject: [PATCH] sdk_dpaa: update comments about recycling and back-pointer
|
||
|
|
storage
|
||
|
|
|
||
|
|
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
|
||
|
|
---
|
||
|
|
drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 18 ++++++++++++++++--
|
||
|
|
1 file changed, 16 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
|
||
|
|
+++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
|
||
|
|
@@ -121,6 +121,10 @@ static int _dpa_bp_add_8_bufs(const stru
|
||
|
|
put_page(virt_to_head_page(new_buf));
|
||
|
|
goto build_skb_failed;
|
||
|
|
}
|
||
|
|
+
|
||
|
|
+ /* Store the skb back-pointer before the start of the buffer.
|
||
|
|
+ * Otherwise it will be overwritten by the FMan.
|
||
|
|
+ */
|
||
|
|
DPA_WRITE_SKB_PTR(skb, skbh, new_buf, -1);
|
||
|
|
|
||
|
|
addr = dma_map_single(dev, new_buf,
|
||
|
|
@@ -344,7 +348,10 @@ bool dpa_buf_is_recyclable(struct sk_buf
|
||
|
|
* - buffer address aligned to cacheline bytes
|
||
|
|
* - offset of data from start of buffer no lower than a minimum value
|
||
|
|
* - offset of data from start of buffer no higher than a maximum value
|
||
|
|
+ * - the skb back-pointer is stored safely
|
||
|
|
*/
|
||
|
|
+
|
||
|
|
+ /* guarantee both the minimum size and the minimum data offset */
|
||
|
|
new = min(skb_end_pointer(skb) - min_size, skb->data - min_offset);
|
||
|
|
|
||
|
|
/* left align to the nearest cacheline */
|
||
|
|
@@ -694,6 +701,9 @@ int __hot skb_to_contig_fd(struct dpa_pr
|
||
|
|
dma_dir = DMA_BIDIRECTIONAL;
|
||
|
|
dma_map_size = dpa_bp->size;
|
||
|
|
|
||
|
|
+ /* Store the skb back-pointer before the start of the buffer.
|
||
|
|
+ * Otherwise it will be overwritten by the FMan.
|
||
|
|
+ */
|
||
|
|
DPA_WRITE_SKB_PTR(skb, skbh, buffer_start, -1);
|
||
|
|
*offset = skb_headroom(skb) - fd->offset;
|
||
|
|
} else
|
||
|
|
@@ -711,7 +721,7 @@ int __hot skb_to_contig_fd(struct dpa_pr
|
||
|
|
|
||
|
|
/* The buffer will be Tx-confirmed, but the TxConf cb must
|
||
|
|
* necessarily look at our Tx private data to retrieve the
|
||
|
|
- * skbuff. (In short: can't use DPA_WRITE_SKB_PTR() here.)
|
||
|
|
+ * skbuff. Store the back-pointer inside the buffer.
|
||
|
|
*/
|
||
|
|
DPA_WRITE_SKB_PTR(skb, skbh, buffer_start, 0);
|
||
|
|
}
|
||
|
|
@@ -975,7 +985,11 @@ int __hot skb_to_sg_fd(struct dpa_priv_s
|
||
|
|
fd->length20 = skb->len;
|
||
|
|
fd->offset = priv->tx_headroom;
|
||
|
|
|
||
|
|
- /* DMA map the SGT page */
|
||
|
|
+ /* DMA map the SGT page
|
||
|
|
+ *
|
||
|
|
+ * It's safe to store the skb back-pointer inside the buffer since
|
||
|
|
+ * S/G frames are non-recyclable.
|
||
|
|
+ */
|
||
|
|
DPA_WRITE_SKB_PTR(skb, skbh, sgt_buf, 0);
|
||
|
|
addr = dma_map_single(dpa_bp->dev, sgt_buf,
|
||
|
|
priv->tx_headroom + sgt_size,
|