Commit 59e9bf03 authored by Shenwei Wang's avatar Shenwei Wang Committed by Jakub Kicinski
Browse files

net: fec: add change_mtu to support dynamic buffer allocation 



Add a fec_change_mtu() handler to recalculate the pagepool_order based on
the new_mtu value. And update the rx_frame_size accordingly when
pagepool_order changes.

MTU changes are only allowed when the adater is not running.

Reviewed-by: default avatarWei Fang <wei.fang@nxp.com>
Signed-off-by: default avatarShenwei Wang <shenwei.wang@nxp.com>
Link: https://patch.msgid.link/20250910185211.721341-6-shenwei.wang@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5b14ed3a

drivers/net/ethernet/freescale/fec.h

+3 −2
Original line number Diff line number Diff line
@@ -348,10 +348,11 @@ struct bufdesc_ex { 
 * the skbuffer directly.

 */



#define FEC_DRV_RESERVE_SPACE (XDP_PACKET_HEADROOM + \

		SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))

#define FEC_ENET_XDP_HEADROOM	(XDP_PACKET_HEADROOM)

#define FEC_ENET_RX_PAGES	256

#define FEC_ENET_RX_FRSIZE	(PAGE_SIZE - FEC_ENET_XDP_HEADROOM \

		- SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))

#define FEC_ENET_RX_FRSIZE	(PAGE_SIZE - FEC_DRV_RESERVE_SPACE)

#define FEC_ENET_RX_FRPPG	(PAGE_SIZE / FEC_ENET_RX_FRSIZE)

#define RX_RING_SIZE		(FEC_ENET_RX_FRPPG * FEC_ENET_RX_PAGES)

#define FEC_ENET_TX_FRSIZE	2048

drivers/net/ethernet/freescale/fec_main.c

+20 −2
Original line number Diff line number Diff line
@@ -470,14 +470,14 @@ fec_enet_create_page_pool(struct fec_enet_private *fep, 
{

	struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);

	struct page_pool_params pp_params = {

		.order = 0,

		.order = fep->pagepool_order,

		.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,

		.pool_size = size,

		.nid = dev_to_node(&fep->pdev->dev),

		.dev = &fep->pdev->dev,

		.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,

		.offset = FEC_ENET_XDP_HEADROOM,

		.max_len = FEC_ENET_RX_FRSIZE,

		.max_len = fep->rx_frame_size,

	};

	int err;
@@ -4025,6 +4025,23 @@ static int fec_hwtstamp_set(struct net_device *ndev, 
	return fec_ptp_set(ndev, config, extack);

}



static int fec_change_mtu(struct net_device *ndev, int new_mtu)

{

	struct fec_enet_private *fep = netdev_priv(ndev);

	int order;



	if (netif_running(ndev))

		return -EBUSY;



	order = get_order(new_mtu + ETH_HLEN + ETH_FCS_LEN

			  + FEC_DRV_RESERVE_SPACE);

	fep->rx_frame_size = (PAGE_SIZE << order) - FEC_DRV_RESERVE_SPACE;

	fep->pagepool_order = order;

	WRITE_ONCE(ndev->mtu, new_mtu);



	return 0;

}



static const struct net_device_ops fec_netdev_ops = {

	.ndo_open		= fec_enet_open,

	.ndo_stop		= fec_enet_close,
@@ -4034,6 +4051,7 @@ static const struct net_device_ops fec_netdev_ops = { 
	.ndo_validate_addr	= eth_validate_addr,

	.ndo_tx_timeout		= fec_timeout,

	.ndo_set_mac_address	= fec_set_mac_address,

	.ndo_change_mtu		= fec_change_mtu,

	.ndo_eth_ioctl		= phy_do_ioctl_running,

	.ndo_set_features	= fec_set_features,

	.ndo_bpf		= fec_enet_bpf,