[PATCH net-next 2/4] igb: Introduce XSK data structures and helpers

Tony Nguyen
2024-08-08T18:36:05Z

From: Sriram Yagnaraman <sriram.yagnaraman@est.tech>

Add the following ring flags
- IGB_RING_FLAG_TX_DISABLED (when xsk pool is being setup)
- IGB_RING_FLAG_AF_XDP_ZC (xsk pool is active)

Add a xdp_buff array for use with XSK receive batch API, and a pointer
to xsk_pool in igb_adapter.

Add enable/disable functions for TX and RX rings
Add enable/disable functions for XSK pool
Add xsk wakeup function

None of the above functionality will be active until
NETDEV_XDP_ACT_XSK_ZEROCOPY is advertised in netdev->xdp_features.

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
drivers/net/ethernet/intel/igb/Makefile | 2 +-
drivers/net/ethernet/intel/igb/igb.h | 14 +-
drivers/net/ethernet/intel/igb/igb_main.c | 9 +
drivers/net/ethernet/intel/igb/igb_xsk.c | 210 ++++++++++++++++++++++
4 files changed, 233 insertions(+), 2 deletions(-)
create mode 100644 drivers/net/ethernet/intel/igb/igb_xsk.c

diff --git a/drivers/net/ethernet/intel/igb/Makefile b/drivers/net/ethernet/intel/igb/Makefile
index 463c0d26b9d4..6c1b702fd992 100644
--- a/drivers/net/ethernet/intel/igb/Makefile
+++ b/drivers/net/ethernet/intel/igb/Makefile
@@ -8,4 +8,4 @@ obj-$(CONFIG_IGB) += igb.o

igb-y := igb_main.o igb_ethtool.o e1000_82575.o \
e1000_mac.o e1000_nvm.o e1000_phy.o e1000_mbx.o \
- e1000_i210.o igb_ptp.o igb_hwmon.o
+ e1000_i210.o igb_ptp.o igb_hwmon.o igb_xsk.o
diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 0de71ec324ed..053130c01480 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -20,6 +20,7 @@
#include <linux/mdio.h>

#include <net/xdp.h>
+#include <net/xdp_sock_drv.h>

struct igb_adapter;

@@ -320,6 +321,7 @@ struct igb_ring {
union { /* array of buffer info structs */
struct igb_tx_buffer *tx_buffer_info;
struct igb_rx_buffer *rx_buffer_info;
+ struct xdp_buff **rx_buffer_info_zc;
};
void *desc; /* descriptor ring memory */
unsigned long flags; /* ring specific flags */
@@ -357,6 +359,7 @@ struct igb_ring {
};
};
struct xdp_rxq_info xdp_rxq;
+ struct xsk_buff_pool *xsk_pool;
} ____cacheline_internodealigned_in_smp;

struct igb_q_vector {
@@ -384,7 +387,9 @@ enum e1000_ring_flags_t {
IGB_RING_FLAG_RX_SCTP_CSUM,
IGB_RING_FLAG_RX_LB_VLAN_BSWAP,
IGB_RING_FLAG_TX_CTX_IDX,
- IGB_RING_FLAG_TX_DETECT_HANG
+ IGB_RING_FLAG_TX_DETECT_HANG,
+ IGB_RING_FLAG_TX_DISABLED,
+ IGB_RING_FLAG_AF_XDP_ZC
};

#define ring_uses_large_buffer(ring) \
@@ -822,4 +827,11 @@ int igb_add_mac_steering_filter(struct igb_adapter *adapter,
int igb_del_mac_steering_filter(struct igb_adapter *adapter,
const u8 *addr, u8 queue, u8 flags);

+struct xsk_buff_pool *igb_xsk_pool(struct igb_adapter *adapter,
+ struct igb_ring *ring);
+int igb_xsk_pool_setup(struct igb_adapter *adapter,
+ struct xsk_buff_pool *pool,
+ u16 qid);
+int igb_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags);
+
#endif /* _IGB_H_ */
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index bdb7637559b8..b6f23bbeff71 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2904,9 +2904,14 @@ static int igb_xdp_setup(struct net_device *dev, struct netdev_bpf *bpf)

static int igb_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
+ struct igb_adapter *adapter = netdev_priv(dev);
+
switch (xdp->command) {
case XDP_SETUP_PROG:
return igb_xdp_setup(dev, xdp);
+ case XDP_SETUP_XSK_POOL:
+ return igb_xsk_pool_setup(adapter, xdp->xsk.pool,
+ xdp->xsk.queue_id);
default:
return -EINVAL;
}
@@ -3033,6 +3038,7 @@ static const struct net_device_ops igb_netdev_ops = {
.ndo_setup_tc = igb_setup_tc,
.ndo_bpf = igb_xdp,
.ndo_xdp_xmit = igb_xdp_xmit,
+ .ndo_xsk_wakeup = igb_xsk_wakeup,
};

/**
@@ -4355,6 +4361,8 @@ void igb_configure_tx_ring(struct igb_adapter *adapter,
u64 tdba = ring->dma;
int reg_idx = ring->reg_idx;

+ ring->xsk_pool = igb_xsk_pool(adapter, ring);
+
wr32(E1000_TDLEN(reg_idx),
ring->count * sizeof(union e1000_adv_tx_desc));
wr32(E1000_TDBAL(reg_idx),
@@ -4750,6 +4758,7 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
xdp_rxq_info_unreg_mem_model(&ring->xdp_rxq);
WARN_ON(xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
MEM_TYPE_PAGE_SHARED, NULL));
+ ring->xsk_pool = igb_xsk_pool(adapter, ring);

/* disable the queue */
wr32(E1000_RXDCTL(reg_idx), 0);
diff --git a/drivers/net/ethernet/intel/igb/igb_xsk.c b/drivers/net/ethernet/intel/igb/igb_xsk.c
new file mode 100644
index 000000000000..925bf97f7caa
--- /dev/null
+++ b/drivers/net/ethernet/intel/igb/igb_xsk.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2018 Intel Corporation. */
+
+#include <linux/bpf_trace.h>
+#include <net/xdp_sock_drv.h>
+#include <net/xdp.h>
+
+#include "e1000_hw.h"
+#include "igb.h"
+
+static int igb_realloc_rx_buffer_info(struct igb_ring *ring, bool pool_present)
+{
+ int size = pool_present ?
+ sizeof(*ring->rx_buffer_info_zc) * ring->count :
+ sizeof(*ring->rx_buffer_info) * ring->count;
+ void *buff_info = vmalloc(size);
+
+ if (!buff_info)
+ return -ENOMEM;
+
+ if (pool_present) {
+ vfree(ring->rx_buffer_info);
+ ring->rx_buffer_info = NULL;
+ ring->rx_buffer_info_zc = buff_info;
+ } else {
+ vfree(ring->rx_buffer_info_zc);
+ ring->rx_buffer_info_zc = NULL;
+ ring->rx_buffer_info = buff_info;
+ }
+
+ return 0;
+}
+
+static void igb_txrx_ring_disable(struct igb_adapter *adapter, u16 qid)
+{
+ struct igb_ring *tx_ring = adapter->tx_ring[qid];
+ struct igb_ring *rx_ring = adapter->rx_ring[qid];
+ struct e1000_hw *hw = &adapter->hw;
+
+ set_bit(IGB_RING_FLAG_TX_DISABLED, &tx_ring->flags);
+
+ wr32(E1000_TXDCTL(tx_ring->reg_idx), 0);
+ wr32(E1000_RXDCTL(rx_ring->reg_idx), 0);
+
+ /* Rx/Tx share the same napi context. */
+ napi_disable(&rx_ring->q_vector->napi);
+
+ igb_clean_tx_ring(tx_ring);
+ igb_clean_rx_ring(rx_ring);
+
+ memset(&rx_ring->rx_stats, 0, sizeof(rx_ring->rx_stats));
+ memset(&tx_ring->tx_stats, 0, sizeof(tx_ring->tx_stats));
+}
+
+static void igb_txrx_ring_enable(struct igb_adapter *adapter, u16 qid)
+{
+ struct igb_ring *tx_ring = adapter->tx_ring[qid];
+ struct igb_ring *rx_ring = adapter->rx_ring[qid];
+
+ igb_configure_tx_ring(adapter, tx_ring);
+ igb_configure_rx_ring(adapter, rx_ring);
+
+ clear_bit(IGB_RING_FLAG_TX_DISABLED, &tx_ring->flags);
+
+ /* call igb_desc_unused which always leaves
+ * at least 1 descriptor unused to make sure
+ * next_to_use != next_to_clean
+ */
+ igb_alloc_rx_buffers(rx_ring, igb_desc_unused(rx_ring));
+
+ /* Rx/Tx share the same napi context. */
+ napi_enable(&rx_ring->q_vector->napi);
+}
+
+struct xsk_buff_pool *igb_xsk_pool(struct igb_adapter *adapter,
+ struct igb_ring *ring)
+{
+ int qid = ring->queue_index;
+
+ if (!igb_xdp_is_enabled(adapter) ||
+ !test_bit(IGB_RING_FLAG_AF_XDP_ZC, &ring->flags))
+ return NULL;
+
+ return xsk_get_pool_from_qid(adapter->netdev, qid);
+}
+
+static int igb_xsk_pool_enable(struct igb_adapter *adapter,
+ struct xsk_buff_pool *pool,
+ u16 qid)
+{
+ struct net_device *netdev = adapter->netdev;
+ struct igb_ring *tx_ring, *rx_ring;
+ bool if_running;
+ int err;
+
+ if (qid >= adapter->num_rx_queues)
+ return -EINVAL;
+
+ if (qid >= netdev->real_num_rx_queues ||
+ qid >= netdev->real_num_tx_queues)
+ return -EINVAL;
+
+ err = xsk_pool_dma_map(pool, &adapter->pdev->dev, IGB_RX_DMA_ATTR);
+ if (err)
+ return err;
+
+ tx_ring = adapter->tx_ring[qid];
+ rx_ring = adapter->rx_ring[qid];
+ if_running = netif_running(adapter->netdev) && igb_xdp_is_enabled(adapter);
+ if (if_running)
+ igb_txrx_ring_disable(adapter, qid);
+
+ set_bit(IGB_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
+ set_bit(IGB_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
+
+ if (if_running) {
+ err = igb_realloc_rx_buffer_info(rx_ring, true);
+ if (!err) {
+ igb_txrx_ring_enable(adapter, qid);
+ /* Kick start the NAPI context so that receiving will start */
+ err = igb_xsk_wakeup(adapter->netdev, qid, XDP_WAKEUP_RX);
+ }
+
+ if (err) {
+ clear_bit(IGB_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
+ clear_bit(IGB_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
+ xsk_pool_dma_unmap(pool, IGB_RX_DMA_ATTR);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+static int igb_xsk_pool_disable(struct igb_adapter *adapter, u16 qid)
+{
+ struct igb_ring *tx_ring, *rx_ring;
+ struct xsk_buff_pool *pool;
+ bool if_running;
+ int err;
+
+ pool = xsk_get_pool_from_qid(adapter->netdev, qid);
+ if (!pool)
+ return -EINVAL;
+
+ tx_ring = adapter->tx_ring[qid];
+ rx_ring = adapter->rx_ring[qid];
+ if_running = netif_running(adapter->netdev) && igb_xdp_is_enabled(adapter);
+ if (if_running)
+ igb_txrx_ring_disable(adapter, qid);
+
+ xsk_pool_dma_unmap(pool, IGB_RX_DMA_ATTR);
+ clear_bit(IGB_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
+ clear_bit(IGB_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
+
+ if (if_running) {
+ err = igb_realloc_rx_buffer_info(rx_ring, false);
+ if (err)
+ return err;
+
+ igb_txrx_ring_enable(adapter, qid);
+ }
+
+ return 0;
+}
+
+int igb_xsk_pool_setup(struct igb_adapter *adapter,
+ struct xsk_buff_pool *pool,
+ u16 qid)
+{
+ return pool ? igb_xsk_pool_enable(adapter, pool, qid) :
+ igb_xsk_pool_disable(adapter, qid);
+}
+
+int igb_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
+{
+ struct igb_adapter *adapter = netdev_priv(dev);
+ struct e1000_hw *hw = &adapter->hw;
+ struct igb_ring *ring;
+ u32 eics = 0;
+
+ if (test_bit(__IGB_DOWN, &adapter->state))
+ return -ENETDOWN;
+
+ if (!igb_xdp_is_enabled(adapter))
+ return -EINVAL;
+
+ if (qid >= adapter->num_tx_queues)
+ return -EINVAL;
+
+ ring = adapter->tx_ring[qid];
+
+ if (test_bit(IGB_RING_FLAG_TX_DISABLED, &ring->flags))
+ return -ENETDOWN;
+
+ if (!ring->xsk_pool)
+ return -EINVAL;
+
+ if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
+ /* Cause software interrupt to ensure Rx ring is cleaned */
+ if (adapter->flags & IGB_FLAG_HAS_MSIX) {
+ eics |= ring->q_vector->eims_value;
+ wr32(E1000_EICS, eics);
+ } else {
+ wr32(E1000_ICS, E1000_ICS_RXDMT0);
+ }
+ }
+
+ return 0;
+}
--
2.42.0