From 6f0d16cc5cb70910d723903e3a85961ca3841479 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@kernel.org>
Date: Tue, 18 Jan 2022 11:22:04 +0100
Subject: [PATCH 18/34] net: cpsw: avoid alignment faults by taking
 NET_IP_ALIGN into account
Git-commit: 1771afd47430f5e95c9c3a2e3a8a63e67402d3fe
References: git-fixes
Patch-mainline: v5.17-rc1

Both versions of the CPSW driver declare a CPSW_HEADROOM_NA macro that
takes NET_IP_ALIGN into account, but fail to use it appropriately when
storing incoming packets in memory. This results in the IPv4 source and
destination addresses to appear misaligned in memory, which causes
aligment faults that need to be fixed up in software.

So let's switch from CPSW_HEADROOM to CPSW_HEADROOM_NA where needed.
This gets rid of any alignment faults on the RX path on a Beaglebone
White.

Fixes: 9ed4050c0d75 ("net: ethernet: ti: cpsw: add XDP support")
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
 drivers/net/ethernet/ti/cpsw.c      | 6 +++---
 drivers/net/ethernet/ti/cpsw_new.c  | 6 +++---
 drivers/net/ethernet/ti/cpsw_priv.c | 2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 1ba39b6cb030..b38619b43255 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -349,7 +349,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
 	struct cpsw_common	*cpsw = ndev_to_cpsw(xmeta->ndev);
 	int			pkt_size = cpsw->rx_packet_max;
 	int			ret = 0, port, ch = xmeta->ch;
-	int			headroom = CPSW_HEADROOM;
+	int			headroom = CPSW_HEADROOM_NA;
 	struct net_device	*ndev = xmeta->ndev;
 	struct cpsw_priv	*priv;
 	struct page_pool	*pool;
@@ -392,7 +392,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
 	}
 
 	if (priv->xdp_prog) {
-		int headroom = CPSW_HEADROOM, size = len;
+		int size = len;
 
 		xdp_init_buff(&xdp, PAGE_SIZE, &priv->xdp_rxq[ch]);
 		if (status & CPDMA_RX_VLAN_ENCAP) {
@@ -442,7 +442,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
 	xmeta->ndev = ndev;
 	xmeta->ch = ch;
 
-	dma = page_pool_get_dma_addr(new_page) + CPSW_HEADROOM;
+	dma = page_pool_get_dma_addr(new_page) + CPSW_HEADROOM_NA;
 	ret = cpdma_chan_submit_mapped(cpsw->rxv[ch].ch, new_page, dma,
 				       pkt_size, 0);
 	if (ret < 0) {
diff --git a/drivers/net/ethernet/ti/cpsw_new.c b/drivers/net/ethernet/ti/cpsw_new.c
index d7f35fc16cc0..73609396d985 100644
--- a/drivers/net/ethernet/ti/cpsw_new.c
+++ b/drivers/net/ethernet/ti/cpsw_new.c
@@ -282,7 +282,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
 {
 	struct page *new_page, *page = token;
 	void *pa = page_address(page);
-	int headroom = CPSW_HEADROOM;
+	int headroom = CPSW_HEADROOM_NA;
 	struct cpsw_meta_xdp *xmeta;
 	struct cpsw_common *cpsw;
 	struct net_device *ndev;
@@ -335,7 +335,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
 	}
 
 	if (priv->xdp_prog) {
-		int headroom = CPSW_HEADROOM, size = len;
+		int size = len;
 
 		xdp_init_buff(&xdp, PAGE_SIZE, &priv->xdp_rxq[ch]);
 		if (status & CPDMA_RX_VLAN_ENCAP) {
@@ -385,7 +385,7 @@ static void cpsw_rx_handler(void *token, int len, int status)
 	xmeta->ndev = ndev;
 	xmeta->ch = ch;
 
-	dma = page_pool_get_dma_addr(new_page) + CPSW_HEADROOM;
+	dma = page_pool_get_dma_addr(new_page) + CPSW_HEADROOM_NA;
 	ret = cpdma_chan_submit_mapped(cpsw->rxv[ch].ch, new_page, dma,
 				       pkt_size, 0);
 	if (ret < 0) {
diff --git a/drivers/net/ethernet/ti/cpsw_priv.c b/drivers/net/ethernet/ti/cpsw_priv.c
index ecc2a6b7e28f..6bb5ac51d23c 100644
--- a/drivers/net/ethernet/ti/cpsw_priv.c
+++ b/drivers/net/ethernet/ti/cpsw_priv.c
@@ -1120,7 +1120,7 @@ int cpsw_fill_rx_channels(struct cpsw_priv *priv)
 			xmeta->ndev = priv->ndev;
 			xmeta->ch = ch;
 
-			dma = page_pool_get_dma_addr(page) + CPSW_HEADROOM;
+			dma = page_pool_get_dma_addr(page) + CPSW_HEADROOM_NA;
 			ret = cpdma_chan_idle_submit_mapped(cpsw->rxv[ch].ch,
 							    page, dma,
 							    cpsw->rx_packet_max,
-- 
2.16.4