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: Wei Fang <wei.fang@nxp.com>
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Link: https://patch.msgid.link/20250910185211.721341-6-shenwei.wang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Shenwei Wang 2025-09-10 13:52:10 -05:00 committed by Jakub Kicinski
parent 5b14ed3ac5
commit 59e9bf037d
2 changed files with 23 additions and 4 deletions

View File

@ -348,10 +348,11 @@ struct bufdesc_ex {
* the skbuffer directly. * 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_XDP_HEADROOM (XDP_PACKET_HEADROOM)
#define FEC_ENET_RX_PAGES 256 #define FEC_ENET_RX_PAGES 256
#define FEC_ENET_RX_FRSIZE (PAGE_SIZE - FEC_ENET_XDP_HEADROOM \ #define FEC_ENET_RX_FRSIZE (PAGE_SIZE - FEC_DRV_RESERVE_SPACE)
- SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
#define FEC_ENET_RX_FRPPG (PAGE_SIZE / FEC_ENET_RX_FRSIZE) #define FEC_ENET_RX_FRPPG (PAGE_SIZE / FEC_ENET_RX_FRSIZE)
#define RX_RING_SIZE (FEC_ENET_RX_FRPPG * FEC_ENET_RX_PAGES) #define RX_RING_SIZE (FEC_ENET_RX_FRPPG * FEC_ENET_RX_PAGES)
#define FEC_ENET_TX_FRSIZE 2048 #define FEC_ENET_TX_FRSIZE 2048

View File

@ -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 bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
struct page_pool_params pp_params = { struct page_pool_params pp_params = {
.order = 0, .order = fep->pagepool_order,
.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV, .flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
.pool_size = size, .pool_size = size,
.nid = dev_to_node(&fep->pdev->dev), .nid = dev_to_node(&fep->pdev->dev),
.dev = &fep->pdev->dev, .dev = &fep->pdev->dev,
.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE, .dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
.offset = FEC_ENET_XDP_HEADROOM, .offset = FEC_ENET_XDP_HEADROOM,
.max_len = FEC_ENET_RX_FRSIZE, .max_len = fep->rx_frame_size,
}; };
int err; int err;
@ -4025,6 +4025,23 @@ static int fec_hwtstamp_set(struct net_device *ndev,
return fec_ptp_set(ndev, config, extack); 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 = { static const struct net_device_ops fec_netdev_ops = {
.ndo_open = fec_enet_open, .ndo_open = fec_enet_open,
.ndo_stop = fec_enet_close, .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_validate_addr = eth_validate_addr,
.ndo_tx_timeout = fec_timeout, .ndo_tx_timeout = fec_timeout,
.ndo_set_mac_address = fec_set_mac_address, .ndo_set_mac_address = fec_set_mac_address,
.ndo_change_mtu = fec_change_mtu,
.ndo_eth_ioctl = phy_do_ioctl_running, .ndo_eth_ioctl = phy_do_ioctl_running,
.ndo_set_features = fec_set_features, .ndo_set_features = fec_set_features,
.ndo_bpf = fec_enet_bpf, .ndo_bpf = fec_enet_bpf,