Hi Shenwei,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on net-next/master]
[also build test WARNING on net/master linus/master v6.1-rc2 next-20221026]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Shenwei-Wang/net-fec-add-initial-XDP-support/20221026-041331
patch link: https://lore.kernel.org/r/20221025201156.776576-1-shenwei.wang%40nxp.com
patch subject: [PATCH 1/1] net: fec: add initial XDP support
config: hexagon-randconfig-r033-20221024 (attached as .config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 791a7ae1ba3efd6bca96338e10ffde557ba83920)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/f601d09cdead68e49ba67efbb904277b697c2f66
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Shenwei-Wang/net-fec-add-initial-XDP-support/20221026-041331
git checkout f601d09cdead68e49ba67efbb904277b697c2f66
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash drivers/net/ethernet/freescale/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from drivers/net/ethernet/freescale/fec_main.c:33:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from drivers/net/ethernet/freescale/fec_main.c:33:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from drivers/net/ethernet/freescale/fec_main.c:33:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
>> drivers/net/ethernet/freescale/fec_main.c:3692:9: warning: variable 'nxmit' set but not used [-Wunused-but-set-variable]
int i, nxmit = 0;
^
7 warnings generated.
vim +/nxmit +3692 drivers/net/ethernet/freescale/fec_main.c
3681
3682 static int fec_enet_xdp_xmit(struct net_device *dev,
3683 int num_frames,
3684 struct xdp_frame **frames,
3685 u32 flags)
3686 {
3687 struct fec_enet_private *fep = netdev_priv(dev);
3688 struct fec_enet_priv_tx_q *txq;
3689 int cpu = smp_processor_id();
3690 struct netdev_queue *nq;
3691 unsigned int queue;
> 3692 int i, nxmit = 0;
3693
3694 queue = fec_enet_xdp_get_tx_queue(fep, cpu);
3695 txq = fep->tx_queue[queue];
3696 nq = netdev_get_tx_queue(fep->netdev, queue);
3697
3698 __netif_tx_lock(nq, cpu);
3699
3700 for (i = 0; i < num_frames; i++) {
3701 fec_enet_txq_xmit_frame(fep, txq, frames[i]);
3702 nxmit++;
3703 }
3704
3705 /* Make sure the update to bdp and tx_skbuff are performed. */
3706 wmb();
3707
3708 /* Trigger transmission start */
3709 writel(0, txq->bd.reg_desc_active);
3710
3711 __netif_tx_unlock(nq);
3712
3713 return num_frames;
3714 }
3715
> -----Original Message-----
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: Tuesday, October 25, 2022 5:09 PM
> To: Shenwei Wang <shenwei.wang@nxp.com>
> Cc: David S. Miller <davem@davemloft.net>; Eric Dumazet
> <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni
> <pabeni@redhat.com>; Alexei Starovoitov <ast@kernel.org>; Daniel Borkmann
> <daniel@iogearbox.net>; Jesper Dangaard Brouer <hawk@kernel.org>; John
> Fastabend <john.fastabend@gmail.com>; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; imx@lists.linux.dev
> Subject: [EXT] Re: [PATCH 1/1] net: fec: add initial XDP support
>
> Caution: EXT Email
>
> > +#define FEC_ENET_XDP_PASS 0
> > +#define FEC_ENET_XDP_CONSUMED BIT(0)
> > +#define FEC_ENET_XDP_TX BIT(1)
> > +#define FEC_ENET_XDP_REDIR BIT(2)
>
> I don't know XDP, so maybe a silly question. Are these action mutually exclusive?
> Are these really bits, or should it be an enum?
> fec_enet_run_xdp() does not combine them as bits.
>
The bit here is to record the states that may required after completing the XDP processing.
As the current implementation for XDP is not full, the other bit like FEC_ENET_XDP_TX is not
used for now. Generally it will require an extra action if a FEC_ENET_XDP_TX is returned.
Because we are processing a batch of packets together, those bits may get combined. It will
then responds to each bit accordingly.
> > +static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf
> > +*bpf) {
> > + struct fec_enet_private *fep = netdev_priv(dev);
> > + bool is_run = netif_running(dev);
>
> You have the space, so maybe call it is_running.
>
> > + struct bpf_prog *old_prog;
> > + unsigned int dsize;
> > + int i;
> > +
> > + switch (bpf->command) {
> > + case XDP_SETUP_PROG:
> > + if (is_run)
> > + fec_enet_close(dev);
>
> fec_net_close() followed by fec_enet_open() is pretty expensive. The PHY is
> stopped and disconnected, and then connected and started. That will probably
> trigger an auto-neg, which takes around 1.5 seconds before the link is up again.
>
> Maybe you should optimise this. I guess the real issue here is you need to resize
> the RX ring. You need to be careful with that anyway. If the machine is under
> memory pressure, you might not be able to allocate the ring, resulting in a
> broken interface. What is recommended for ethtool --set-ring is that you first
> allocate the new ring, and if that is successful, free the old ring. If the allocation
> fails, you still have the old ring, and you can safely return -ENOMEM and still
> have a working interface.
>
> So i think you can split this patch up into a few parts:
>
> XDP using the default ring size. Your benchmarks show it works, its just not
> optimal. But the resulting smaller patch will be easier to review.
>
> Add support for ethtool set-ring, which will allow you to pick apart the bits of
> fec_net_close() and fec_enet_open() which are needed for changing the rings.
> This might actually need a refactoring patch?
>
That sounds good. Let me think about it.
Thanks,
Shenwei
> And then add support for optimal ring size for XDP.
>
> Andrew
@@ -348,6 +348,7 @@ struct bufdesc_ex {
*/
#define FEC_ENET_XDP_HEADROOM (XDP_PACKET_HEADROOM)
+#define XDP_RX_RING_SIZE 16
#define FEC_ENET_RX_PAGES 256
#define FEC_ENET_RX_FRSIZE (PAGE_SIZE - FEC_ENET_XDP_HEADROOM \
@@ -663,6 +664,9 @@ struct fec_enet_private {
struct imx_sc_ipc *ipc_handle;
+ /* XDP BPF Program */
+ struct bpf_prog *xdp_prog;
+
u64 ethtool_stats[];
};
@@ -89,6 +89,11 @@ static const u16 fec_enet_vlan_pri_to_queue[8] = {0, 0, 1, 1, 1, 2, 2, 2};
#define FEC_ENET_OPD_V 0xFFF0
#define FEC_MDIO_PM_TIMEOUT 100 /* ms */
+#define FEC_ENET_XDP_PASS 0
+#define FEC_ENET_XDP_CONSUMED BIT(0)
+#define FEC_ENET_XDP_TX BIT(1)
+#define FEC_ENET_XDP_REDIR BIT(2)
+
struct fec_devinfo {
u32 quirks;
};
@@ -418,13 +423,14 @@ static int
fec_enet_create_page_pool(struct fec_enet_private *fep,
struct fec_enet_priv_rx_q *rxq, int size)
{
+ struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
struct page_pool_params pp_params = {
.order = 0,
.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 = DMA_FROM_DEVICE,
+ .dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
.offset = FEC_ENET_XDP_HEADROOM,
.max_len = FEC_ENET_RX_FRSIZE,
};
@@ -1499,6 +1505,59 @@ static void fec_enet_update_cbd(struct fec_enet_priv_rx_q *rxq,
bdp->cbd_bufaddr = cpu_to_fec32(phys_addr);
}
+static u32
+fec_enet_run_xdp(struct fec_enet_private *fep, struct bpf_prog *prog,
+ struct xdp_buff *xdp, struct fec_enet_priv_rx_q *rxq, int index)
+{
+ unsigned int sync, len = xdp->data_end - xdp->data;
+ u32 ret = FEC_ENET_XDP_PASS;
+ struct page *page;
+ int err;
+ u32 act;
+
+ act = bpf_prog_run_xdp(prog, xdp);
+
+ /* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */
+ sync = xdp->data_end - xdp->data_hard_start - FEC_ENET_XDP_HEADROOM;
+ sync = max(sync, len);
+
+ switch (act) {
+ case XDP_PASS:
+ ret = FEC_ENET_XDP_PASS;
+ break;
+
+ case XDP_REDIRECT:
+ err = xdp_do_redirect(fep->netdev, xdp, prog);
+ if (!err) {
+ ret = FEC_ENET_XDP_REDIR;
+ } else {
+ ret = FEC_ENET_XDP_CONSUMED;
+ page = virt_to_head_page(xdp->data);
+ page_pool_put_page(rxq->page_pool, page, sync, true);
+ }
+ break;
+
+ default:
+ bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
+ fallthrough;
+
+ case XDP_TX:
+ bpf_warn_invalid_xdp_action(fep->netdev, prog, act);
+ fallthrough;
+
+ case XDP_ABORTED:
+ fallthrough; /* handle aborts by dropping packet */
+
+ case XDP_DROP:
+ ret = FEC_ENET_XDP_CONSUMED;
+ page = virt_to_head_page(xdp->data);
+ page_pool_put_page(rxq->page_pool, page, sync, true);
+ break;
+ }
+
+ return ret;
+}
+
/* During a receive, the bd_rx.cur points to the current incoming buffer.
* When we update through the ring, if the next incoming buffer has
* not been given to the system, we just set the empty indicator,
@@ -1520,6 +1579,9 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
u16 vlan_tag;
int index = 0;
bool need_swap = fep->quirks & FEC_QUIRK_SWAP_FRAME;
+ struct bpf_prog *xdp_prog = READ_ONCE(fep->xdp_prog);
+ u32 ret, xdp_result = FEC_ENET_XDP_PASS;
+ struct xdp_buff xdp;
struct page *page;
#ifdef CONFIG_M532x
@@ -1531,6 +1593,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
* These get messed up if we get called due to a busy condition.
*/
bdp = rxq->bd.cur;
+ xdp_init_buff(&xdp, PAGE_SIZE, &rxq->xdp_rxq);
while (!((status = fec16_to_cpu(bdp->cbd_sc)) & BD_ENET_RX_EMPTY)) {
@@ -1580,6 +1643,17 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
prefetch(page_address(page));
fec_enet_update_cbd(rxq, bdp, index);
+ if (xdp_prog) {
+ xdp_buff_clear_frags_flag(&xdp);
+ xdp_prepare_buff(&xdp, page_address(page),
+ FEC_ENET_XDP_HEADROOM, pkt_len, false);
+
+ ret = fec_enet_run_xdp(fep, xdp_prog, &xdp, rxq, index);
+ xdp_result |= ret;
+ if (ret != FEC_ENET_XDP_PASS)
+ goto rx_processing_done;
+ }
+
/* The packet length includes FCS, but we don't want to
* include that when passing upstream as it messes up
* bridging applications.
@@ -1675,6 +1749,10 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
writel(0, rxq->bd.reg_desc_active);
}
rxq->bd.cur = bdp;
+
+ if (xdp_result & FEC_ENET_XDP_REDIR)
+ xdp_do_flush_map();
+
return pkt_received;
}
@@ -3476,6 +3554,165 @@ static u16 fec_enet_select_queue(struct net_device *ndev, struct sk_buff *skb,
return fec_enet_vlan_pri_to_queue[vlan_tag >> 13];
}
+static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf *bpf)
+{
+ struct fec_enet_private *fep = netdev_priv(dev);
+ bool is_run = netif_running(dev);
+ struct bpf_prog *old_prog;
+ unsigned int dsize;
+ int i;
+
+ switch (bpf->command) {
+ case XDP_SETUP_PROG:
+ if (is_run)
+ fec_enet_close(dev);
+
+ old_prog = xchg(&fep->xdp_prog, bpf->prog);
+
+ /* Update RX ring size */
+ dsize = fep->bufdesc_ex ? sizeof(struct bufdesc_ex) :
+ sizeof(struct bufdesc);
+ for (i = 0; i < fep->num_rx_queues; i++) {
+ struct fec_enet_priv_rx_q *rxq = fep->rx_queue[i];
+ struct bufdesc *cbd_base;
+ unsigned int size;
+
+ cbd_base = rxq->bd.base;
+ if (bpf->prog)
+ rxq->bd.ring_size = XDP_RX_RING_SIZE;
+ else
+ rxq->bd.ring_size = RX_RING_SIZE;
+ size = dsize * rxq->bd.ring_size;
+ cbd_base = (struct bufdesc *)(((void *)cbd_base) + size);
+ rxq->bd.last = (struct bufdesc *)(((void *)cbd_base) - dsize);
+ }
+
+ if (is_run)
+ fec_enet_open(dev);
+
+ if (old_prog)
+ bpf_prog_put(old_prog);
+
+ return 0;
+
+ case XDP_SETUP_XSK_POOL:
+ return -EOPNOTSUPP;
+
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int
+fec_enet_xdp_get_tx_queue(struct fec_enet_private *fep, int cpu)
+{
+ int index = cpu;
+
+ if (unlikely(index < 0))
+ index = 0;
+
+ while (index >= fep->num_tx_queues)
+ index -= fep->num_tx_queues;
+
+ return index;
+}
+
+static int fec_enet_txq_xmit_frame(struct fec_enet_private *fep,
+ struct fec_enet_priv_tx_q *txq,
+ struct xdp_frame *frame)
+{
+ unsigned int index, status, estatus;
+ struct bufdesc *bdp, *last_bdp;
+ dma_addr_t dma_addr;
+ int entries_free;
+
+ entries_free = fec_enet_get_free_txdesc_num(txq);
+ if (entries_free < MAX_SKB_FRAGS + 1) {
+ netdev_err(fep->netdev, "NOT enough BD for SG!\n");
+ return NETDEV_TX_OK;
+ }
+
+ /* Fill in a Tx ring entry */
+ bdp = txq->bd.cur;
+ last_bdp = bdp;
+ status = fec16_to_cpu(bdp->cbd_sc);
+ status &= ~BD_ENET_TX_STATS;
+
+ index = fec_enet_get_bd_index(bdp, &txq->bd);
+
+ dma_addr = dma_map_single(&fep->pdev->dev, frame->data,
+ frame->len, DMA_TO_DEVICE);
+ if (dma_mapping_error(&fep->pdev->dev, dma_addr))
+ return FEC_ENET_XDP_CONSUMED;
+
+ status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
+ if (fep->bufdesc_ex)
+ estatus = BD_ENET_TX_INT;
+
+ bdp->cbd_bufaddr = cpu_to_fec32(dma_addr);
+ bdp->cbd_datlen = cpu_to_fec16(frame->len);
+
+ if (fep->bufdesc_ex) {
+ struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
+
+ if (fep->quirks & FEC_QUIRK_HAS_AVB)
+ estatus |= FEC_TX_BD_FTYPE(txq->bd.qid);
+
+ ebdp->cbd_bdu = 0;
+ ebdp->cbd_esc = cpu_to_fec32(estatus);
+ }
+
+ index = fec_enet_get_bd_index(last_bdp, &txq->bd);
+ txq->tx_skbuff[index] = NULL;
+
+ /* Send it on its way. Tell FEC it's ready, interrupt when done,
+ * it's the last BD of the frame, and to put the CRC on the end.
+ */
+ status |= (BD_ENET_TX_READY | BD_ENET_TX_TC);
+ bdp->cbd_sc = cpu_to_fec16(status);
+
+ /* If this was the last BD in the ring, start at the beginning again. */
+ bdp = fec_enet_get_nextdesc(last_bdp, &txq->bd);
+
+ txq->bd.cur = bdp;
+
+ return 0;
+}
+
+static int fec_enet_xdp_xmit(struct net_device *dev,
+ int num_frames,
+ struct xdp_frame **frames,
+ u32 flags)
+{
+ struct fec_enet_private *fep = netdev_priv(dev);
+ struct fec_enet_priv_tx_q *txq;
+ int cpu = smp_processor_id();
+ struct netdev_queue *nq;
+ unsigned int queue;
+ int i, nxmit = 0;
+
+ queue = fec_enet_xdp_get_tx_queue(fep, cpu);
+ txq = fep->tx_queue[queue];
+ nq = netdev_get_tx_queue(fep->netdev, queue);
+
+ __netif_tx_lock(nq, cpu);
+
+ for (i = 0; i < num_frames; i++) {
+ fec_enet_txq_xmit_frame(fep, txq, frames[i]);
+ nxmit++;
+ }
+
+ /* Make sure the update to bdp and tx_skbuff are performed. */
+ wmb();
+
+ /* Trigger transmission start */
+ writel(0, txq->bd.reg_desc_active);
+
+ __netif_tx_unlock(nq);
+
+ return num_frames;
+}
+
static const struct net_device_ops fec_netdev_ops = {
.ndo_open = fec_enet_open,
.ndo_stop = fec_enet_close,
@@ -3490,6 +3727,8 @@ static const struct net_device_ops fec_netdev_ops = {
.ndo_poll_controller = fec_poll_controller,
#endif
.ndo_set_features = fec_set_features,
+ .ndo_bpf = fec_enet_bpf,
+ .ndo_xdp_xmit = fec_enet_xdp_xmit,
};
static const unsigned short offset_des_active_rxq[] = {