Openwrt/target/linux/layerscape/patches-5.4/701-net-0080-sdk_dpaa-store-the-skb-backpointer-in-the-skb-headro.patch
Yangbo Lu cddd459140 layerscape: add patches-5.4
Add patches for linux-5.4. The patches are from NXP LSDK-20.04 release
which was tagged LSDK-20.04-V5.4.
https://source.codeaurora.org/external/qoriq/qoriq-components/linux/

For boards LS1021A-IOT, and Traverse-LS1043 which are not involved in
LSDK, port the dts patches from 4.14.

The patches are sorted into the following categories:
  301-arch-xxxx
  302-dts-xxxx
  303-core-xxxx
  701-net-xxxx
  801-audio-xxxx
  802-can-xxxx
  803-clock-xxxx
  804-crypto-xxxx
  805-display-xxxx
  806-dma-xxxx
  807-gpio-xxxx
  808-i2c-xxxx
  809-jailhouse-xxxx
  810-keys-xxxx
  811-kvm-xxxx
  812-pcie-xxxx
  813-pm-xxxx
  814-qe-xxxx
  815-sata-xxxx
  816-sdhc-xxxx
  817-spi-xxxx
  818-thermal-xxxx
  819-uart-xxxx
  820-usb-xxxx
  821-vfio-xxxx

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
2020-05-07 12:53:06 +02:00

85 lines
3.2 KiB
Diff

From 1f00fa355829b510beb900ce1136f40802e6076e Mon Sep 17 00:00:00 2001
From: Camelia Groza <camelia.groza@nxp.com>
Date: Mon, 10 Sep 2018 14:31:05 +0300
Subject: [PATCH] sdk_dpaa: store the skb backpointer in the skb headroom
The skb backpointer is stored right before the FMan buffer, in order to
avoid overwriting. The memory area storing the backpointer was outside of
the skb. This made it hard to guarantee its size.
This patch changes the layout of the skb at buffer seed time: the area
reserved for storing the skb backpointer is part of the skb's headroom.
This makes it easier to track if the backpointer can be safely stored
when recycling the buffer.
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
---
.../net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 33 ++++++++++++++++------
1 file changed, 24 insertions(+), 9 deletions(-)
--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
+++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
@@ -82,8 +82,8 @@ static void dpa_bp_recycle_frag(struct d
static int _dpa_bp_add_8_bufs(const struct dpa_bp *dpa_bp)
{
+ void *new_buf, *fman_buf;
struct bm_buffer bmb[8];
- void *new_buf;
dma_addr_t addr;
uint8_t i;
struct device *dev = dpa_bp->dev;
@@ -113,21 +113,37 @@ static int _dpa_bp_add_8_bufs(const stru
if (unlikely(!new_buf))
goto netdev_alloc_failed;
- new_buf = PTR_ALIGN(new_buf + SMP_CACHE_BYTES, SMP_CACHE_BYTES);
+ new_buf = PTR_ALIGN(new_buf, SMP_CACHE_BYTES);
- skb = build_skb(new_buf, DPA_SKB_SIZE(dpa_bp->size) +
- SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
+ /* Apart from the buffer that will be used by the FMan, the
+ * skb also guarantees enough space to hold the backpointer
+ * in the headroom and the shared info at the end.
+ */
+ skb = build_skb(new_buf,
+ SMP_CACHE_BYTES + DPA_SKB_SIZE(dpa_bp->size) +
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
if (unlikely(!skb)) {
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.
+ /* Reserve SMP_CACHE_BYTES in the skb's headroom to store the
+ * backpointer. This area will not be synced to, or
+ * overwritten by, the FMan.
+ */
+ skb_reserve(skb, SMP_CACHE_BYTES);
+
+ /* We don't sync the first SMP_CACHE_BYTES of the buffer to
+ * the FMan. The skb backpointer is stored at the end of the
+ * reserved headroom. Otherwise it will be overwritten by the
+ * FMan.
+ * The buffer synced with the FMan starts right after the
+ * reserved headroom.
*/
- DPA_WRITE_SKB_PTR(skb, skbh, new_buf, -1);
+ fman_buf = new_buf + SMP_CACHE_BYTES;
+ DPA_WRITE_SKB_PTR(skb, skbh, fman_buf, -1);
- addr = dma_map_single(dev, new_buf,
+ addr = dma_map_single(dev, fman_buf,
dpa_bp->size, DMA_BIDIRECTIONAL);
if (unlikely(dma_mapping_error(dev, addr)))
goto dma_map_failed;
@@ -477,7 +493,6 @@ static struct sk_buff *__hot sg_fd_to_sk
DMA_BIDIRECTIONAL);
if (i == 0) {
DPA_READ_SKB_PTR(skb, skbh, sg_vaddr, -1);
- DPA_BUG_ON(skb->head != sg_vaddr);
#ifdef CONFIG_FSL_DPAA_1588
if (priv->tsu && priv->tsu->valid &&
priv->tsu->hwts_rx_en_ioctl)