kernel: backport MediaTek jumbo frame support

Allow MTU up to 2026 on mediatek, ramips/mt7621 targets.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Tested-by: Stijn Tintel <stijn@linux-ipv6.be>

1 files changed, 138 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.10/611-v5.12-net-ethernet-mediatek-support-setting-MTU.patch b/target/linux/generic/backport-5.10/611-v5.12-net-ethernet-mediatek-support-setting-MTU.patch
new file mode 100644
index 0000000000..289d140f34
--- /dev/null
+++ b/target/linux/generic/backport-5.10/611-v5.12-net-ethernet-mediatek-support-setting-MTU.patch
@@ -0,0 +1,138 @@
+From 4fd59792097a6b2fb949d41264386a7ecade469e Mon Sep 17 00:00:00 2001
+From: DENG Qingfang <dqfext@gmail.com>
+Date: Mon, 25 Jan 2021 12:20:46 +0800
+Subject: [PATCH] net: ethernet: mediatek: support setting MTU
+
+MT762x HW, except for MT7628, supports frame length up to 2048
+(maximum length on GDM), so allow setting MTU up to 2030.
+
+Also set the default frame length to the hardware default 1518.
+
+Signed-off-by: DENG Qingfang <dqfext@gmail.com>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Link: https://lore.kernel.org/r/20210125042046.5599-1-dqfext@gmail.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ drivers/net/ethernet/mediatek/mtk_eth_soc.c | 43 ++++++++++++++++++---
+ drivers/net/ethernet/mediatek/mtk_eth_soc.h | 12 ++++--
+ 2 files changed, 47 insertions(+), 8 deletions(-)
+
+--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
++++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+@@ -355,7 +355,7 @@ static void mtk_mac_config(struct phylin
+ 	/* Setup gmac */
+ 	mcr_cur = mtk_r32(mac->hw, MTK_MAC_MCR(mac->id));
+ 	mcr_new = mcr_cur;
+-	mcr_new |= MAC_MCR_MAX_RX_1536 | MAC_MCR_IPG_CFG | MAC_MCR_FORCE_MODE |
++	mcr_new |= MAC_MCR_IPG_CFG | MAC_MCR_FORCE_MODE |
+ 		   MAC_MCR_BACKOFF_EN | MAC_MCR_BACKPR_EN | MAC_MCR_FORCE_LINK;
+ 
+ 	/* Only update control register when needed! */
+@@ -782,8 +782,8 @@ static void mtk_get_stats64(struct net_d
+ static inline int mtk_max_frag_size(int mtu)
+ {
+ 	/* make sure buf_size will be at least MTK_MAX_RX_LENGTH */
+-	if (mtu + MTK_RX_ETH_HLEN < MTK_MAX_RX_LENGTH)
+-		mtu = MTK_MAX_RX_LENGTH - MTK_RX_ETH_HLEN;
++	if (mtu + MTK_RX_ETH_HLEN < MTK_MAX_RX_LENGTH_2K)
++		mtu = MTK_MAX_RX_LENGTH_2K - MTK_RX_ETH_HLEN;
+ 
+ 	return SKB_DATA_ALIGN(MTK_RX_HLEN + mtu) +
+ 		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+@@ -794,7 +794,7 @@ static inline int mtk_max_buf_size(int f
+ 	int buf_size = frag_size - NET_SKB_PAD - NET_IP_ALIGN -
+ 		       SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ 
+-	WARN_ON(buf_size < MTK_MAX_RX_LENGTH);
++	WARN_ON(buf_size < MTK_MAX_RX_LENGTH_2K);
+ 
+ 	return buf_size;
+ }
+@@ -2606,6 +2606,35 @@ static void mtk_uninit(struct net_device
+ 	mtk_rx_irq_disable(eth, ~0);
+ }
+ 
++static int mtk_change_mtu(struct net_device *dev, int new_mtu)
++{
++	int length = new_mtu + MTK_RX_ETH_HLEN;
++	struct mtk_mac *mac = netdev_priv(dev);
++	struct mtk_eth *eth = mac->hw;
++	u32 mcr_cur, mcr_new;
++
++	if (!MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628)) {
++		mcr_cur = mtk_r32(mac->hw, MTK_MAC_MCR(mac->id));
++		mcr_new = mcr_cur & ~MAC_MCR_MAX_RX_MASK;
++
++		if (length <= 1518)
++			mcr_new |= MAC_MCR_MAX_RX(MAC_MCR_MAX_RX_1518);
++		else if (length <= 1536)
++			mcr_new |= MAC_MCR_MAX_RX(MAC_MCR_MAX_RX_1536);
++		else if (length <= 1552)
++			mcr_new |= MAC_MCR_MAX_RX(MAC_MCR_MAX_RX_1552);
++		else
++			mcr_new |= MAC_MCR_MAX_RX(MAC_MCR_MAX_RX_2048);
++
++		if (mcr_new != mcr_cur)
++			mtk_w32(mac->hw, mcr_new, MTK_MAC_MCR(mac->id));
++	}
++
++	dev->mtu = new_mtu;
++
++	return 0;
++}
++
+ static int mtk_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+ {
+ 	struct mtk_mac *mac = netdev_priv(dev);
+@@ -2902,6 +2931,7 @@ static const struct net_device_ops mtk_n
+ 	.ndo_set_mac_address	= mtk_set_mac_address,
+ 	.ndo_validate_addr	= eth_validate_addr,
+ 	.ndo_do_ioctl		= mtk_do_ioctl,
++	.ndo_change_mtu		= mtk_change_mtu,
+ 	.ndo_tx_timeout		= mtk_tx_timeout,
+ 	.ndo_get_stats64        = mtk_get_stats64,
+ 	.ndo_fix_features	= mtk_fix_features,
+@@ -3004,7 +3034,10 @@ static int mtk_add_mac(struct mtk_eth *e
+ 	eth->netdev[id]->irq = eth->irq[0];
+ 	eth->netdev[id]->dev.of_node = np;
+ 
+-	eth->netdev[id]->max_mtu = MTK_MAX_RX_LENGTH - MTK_RX_ETH_HLEN;
++	if (MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628))
++		eth->netdev[id]->max_mtu = MTK_MAX_RX_LENGTH - MTK_RX_ETH_HLEN;
++	else
++		eth->netdev[id]->max_mtu = MTK_MAX_RX_LENGTH_2K - MTK_RX_ETH_HLEN;
+ 
+ 	return 0;
+ 
+--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
++++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+@@ -20,12 +20,13 @@
+ #include "mtk_ppe.h"
+ 
+ #define MTK_QDMA_PAGE_SIZE	2048
+-#define	MTK_MAX_RX_LENGTH	1536
++#define MTK_MAX_RX_LENGTH	1536
++#define MTK_MAX_RX_LENGTH_2K	2048
+ #define MTK_TX_DMA_BUF_LEN	0x3fff
+ #define MTK_DMA_SIZE		512
+ #define MTK_NAPI_WEIGHT		64
+ #define MTK_MAC_COUNT		2
+-#define MTK_RX_ETH_HLEN		(VLAN_ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN)
++#define MTK_RX_ETH_HLEN		(ETH_HLEN + ETH_FCS_LEN)
+ #define MTK_RX_HLEN		(NET_SKB_PAD + MTK_RX_ETH_HLEN + NET_IP_ALIGN)
+ #define MTK_DMA_DUMMY_DESC	0xffffffff
+ #define MTK_DEFAULT_MSG_ENABLE	(NETIF_MSG_DRV | \
+@@ -352,7 +353,12 @@
+ 
+ /* Mac control registers */
+ #define MTK_MAC_MCR(x)		(0x10100 + (x * 0x100))
+-#define MAC_MCR_MAX_RX_1536	BIT(24)
++#define MAC_MCR_MAX_RX_MASK	GENMASK(25, 24)
++#define MAC_MCR_MAX_RX(_x)	(MAC_MCR_MAX_RX_MASK & ((_x) << 24))
++#define MAC_MCR_MAX_RX_1518	0x0
++#define MAC_MCR_MAX_RX_1536	0x1
++#define MAC_MCR_MAX_RX_1552	0x2
++#define MAC_MCR_MAX_RX_2048	0x3
+ #define MAC_MCR_IPG_CFG		(BIT(18) | BIT(16))
+ #define MAC_MCR_FORCE_MODE	BIT(15)
+ #define MAC_MCR_TX_EN		BIT(14)