target/linux/layerscape/patches-5.4/701-net-0025-sdk_dpaa-ls1043a-errata-do-not-recycle-the-realigned.patch

From e8c0a77a831843a66b3ac0048aa6c76bc39b0332 Mon Sep 17 00:00:00 2001
From: Camelia Groza <camelia.groza@nxp.com>
Date: Mon, 4 Sep 2017 14:03:01 +0300
Subject: [PATCH] sdk_dpaa: ls1043a errata: do not recycle the realigned
 buffers

Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
---
 drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h    | 10 ++++++----
 drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c |  9 +++++++++
 2 files changed, 15 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h
+++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth.h
@@ -680,15 +680,17 @@ static inline void _dpa_bp_free_pf(void
 	put_page(virt_to_head_page(addr));
 }
 
-/* TODO: LS1043A SoC has a HW issue regarding FMan DMA transactions; The issue
- * manifests itself at high traffic rates when frames exceed 4K memory
- * boundaries; For the moment, we use a SW workaround to avoid frames larger
- * than 4K or that exceed 4K alignments.
+/* LS1043A SoC has a HW issue regarding FMan DMA transactions; The issue
+ * manifests itself at high traffic rates when frames cross 4K memory
+ * boundaries or when they are not aligned to 16 bytes; For the moment, we
+ * use a SW workaround to avoid frames larger than 4K or that exceed 4K
+ * alignments and to realign the frames to 16 bytes.
  */
 
 #ifndef CONFIG_PPC
 extern bool dpaa_errata_a010022; /* SoC affected by A010022 errata */
 
+#define NONREC_MARK	0x01
 #define HAS_DMA_ISSUE(start, size) \
 	(((u64)(start) + (size)) > (((u64)(start) + 0x1000) & ~0xFFF))
 #define BOUNDARY_4K(start, size) (((u64)(start) + (u64)(size)) & ~0xFFF)
--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
+++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c
@@ -302,6 +302,12 @@ EXPORT_SYMBOL(_dpa_cleanup_tx_fd);
 #ifndef CONFIG_FSL_DPAA_TS
 bool dpa_skb_is_recyclable(struct sk_buff *skb)
 {
+#ifndef CONFIG_PPC
+	/* Do no recycle skbs realigned by the errata workaround */
+	if (unlikely(dpaa_errata_a010022) && skb->mark == NONREC_MARK)
+		return false;
+#endif
+
 	/* No recycling possible if skb buffer is kmalloc'ed  */
 	if (skb->head_frag == 0)
 		return false;
@@ -838,6 +844,9 @@ static struct sk_buff *a010022_realign_s
 	skb_set_network_header(nskb, net_offset);
 	skb_set_transport_header(nskb, trans_offset);
 
+	/* We don't want the buffer to be recycled so we mark it accordingly */
+	nskb->mark = NONREC_MARK;
+
 	dev_kfree_skb(skb);
 	return nskb;