octeontx2-pf: AF_XDP zero copy receive support

This patch adds support to AF_XDP zero copy for CN10K.
This patch specifically adds receive side support. In this approach once
a xdp program with zero copy support on a specific rx queue is enabled,
then that receive quse is disabled/detached from the existing kernel
queue and re-assigned to the umem memory.

Signed-off-by: Suman Ghosh <sumang@marvell.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: sumang-mrvl

drivers/net/ethernet/marvell/octeontx2/nic/Makefile

@@ -9,7 +9,7 @@ obj-$(CONFIG_RVU_ESWITCH) += rvu_rep.o
 
 rvu_nicpf-y := otx2_pf.o otx2_common.o otx2_txrx.o otx2_ethtool.o \
                otx2_flows.o otx2_tc.o cn10k.o otx2_dmac_flt.o \
-               otx2_devlink.o qos_sq.o qos.o
+               otx2_devlink.o qos_sq.o qos.o otx2_xsk.o
 rvu_nicvf-y := otx2_vf.o
 rvu_rep-y := rep.o
 

drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c

@@ -112,9 +112,12 @@ int cn10k_refill_pool_ptrs(void *dev, struct otx2_cq_queue *cq)
 	struct otx2_nic *pfvf = dev;
 	int cnt = cq->pool_ptrs;
 	u64 ptrs[NPA_MAX_BURST];
+	struct otx2_pool *pool;
 	dma_addr_t bufptr;
 	int num_ptrs = 1;
 
+	pool = &pfvf->qset.pool[cq->cq_idx];
+
 	/* Refill pool with new buffers */
 	while (cq->pool_ptrs) {
 		if (otx2_alloc_buffer(pfvf, cq, &bufptr)) {
@@ -124,7 +127,9 @@ int cn10k_refill_pool_ptrs(void *dev, struct otx2_cq_queue *cq)
 			break;
 		}
 		cq->pool_ptrs--;
-		ptrs[num_ptrs] = (u64)bufptr + OTX2_HEAD_ROOM;
+		ptrs[num_ptrs] = pool->xsk_pool ?
+				 (u64)bufptr : (u64)bufptr + OTX2_HEAD_ROOM;
+
 		num_ptrs++;
 		if (num_ptrs == NPA_MAX_BURST || cq->pool_ptrs == 0) {
 			__cn10k_aura_freeptr(pfvf, cq->cq_idx, ptrs,

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c

@@ -17,6 +17,7 @@
 #include "otx2_common.h"
 #include "otx2_struct.h"
 #include "cn10k.h"
+#include "otx2_xsk.h"
 
 static bool otx2_is_pfc_enabled(struct otx2_nic *pfvf)
 {
@@ -549,10 +550,13 @@ static int otx2_alloc_pool_buf(struct otx2_nic *pfvf, struct otx2_pool *pool,
 }
 
 static int __otx2_alloc_rbuf(struct otx2_nic *pfvf, struct otx2_pool *pool,
-			     dma_addr_t *dma)
+			     dma_addr_t *dma, int qidx, int idx)
 {
 	u8 *buf;
 
+	if (pool->xsk_pool)
+		return otx2_xsk_pool_alloc_buf(pfvf, pool, dma, idx);
+
 	if (pool->page_pool)
 		return otx2_alloc_pool_buf(pfvf, pool, dma);
 
@@ -571,20 +575,21 @@ static int __otx2_alloc_rbuf(struct otx2_nic *pfvf, struct otx2_pool *pool,
 }
 
 int otx2_alloc_rbuf(struct otx2_nic *pfvf, struct otx2_pool *pool,
-		    dma_addr_t *dma)
+		    dma_addr_t *dma, int qidx, int idx)
 {
 	int ret;
 
 	local_bh_disable();
-	ret = __otx2_alloc_rbuf(pfvf, pool, dma);
+	ret = __otx2_alloc_rbuf(pfvf, pool, dma, qidx, idx);
 	local_bh_enable();
 	return ret;
 }
 
 int otx2_alloc_buffer(struct otx2_nic *pfvf, struct otx2_cq_queue *cq,
 		      dma_addr_t *dma)
 {
-	if (unlikely(__otx2_alloc_rbuf(pfvf, cq->rbpool, dma)))
+	if (unlikely(__otx2_alloc_rbuf(pfvf, cq->rbpool, dma,
+				       cq->cq_idx, cq->pool_ptrs - 1)))
 		return -ENOMEM;
 	return 0;
 }
@@ -884,7 +889,7 @@ void otx2_sqb_flush(struct otx2_nic *pfvf)
 #define RQ_PASS_LVL_AURA (255 - ((95 * 256) / 100)) /* RED when 95% is full */
 #define RQ_DROP_LVL_AURA (255 - ((99 * 256) / 100)) /* Drop when 99% is full */
 
-static int otx2_rq_init(struct otx2_nic *pfvf, u16 qidx, u16 lpb_aura)
+int otx2_rq_init(struct otx2_nic *pfvf, u16 qidx, u16 lpb_aura)
 {
 	struct otx2_qset *qset = &pfvf->qset;
 	struct nix_aq_enq_req *aq;
@@ -1041,7 +1046,7 @@ int otx2_sq_init(struct otx2_nic *pfvf, u16 qidx, u16 sqb_aura)
 
 }
 
-static int otx2_cq_init(struct otx2_nic *pfvf, u16 qidx)
+int otx2_cq_init(struct otx2_nic *pfvf, u16 qidx)
 {
 	struct otx2_qset *qset = &pfvf->qset;
 	int err, pool_id, non_xdp_queues;
@@ -1057,11 +1062,18 @@ static int otx2_cq_init(struct otx2_nic *pfvf, u16 qidx)
 		cq->cint_idx = qidx;
 		cq->cqe_cnt = qset->rqe_cnt;
 		if (pfvf->xdp_prog) {
-			pool = &qset->pool[qidx];
 			xdp_rxq_info_reg(&cq->xdp_rxq, pfvf->netdev, qidx, 0);
-			xdp_rxq_info_reg_mem_model(&cq->xdp_rxq,
-						   MEM_TYPE_PAGE_POOL,
-						   pool->page_pool);
+			pool = &qset->pool[qidx];
+			if (pool->xsk_pool) {
+				xdp_rxq_info_reg_mem_model(&cq->xdp_rxq,
+							   MEM_TYPE_XSK_BUFF_POOL,
+							   NULL);
+				xsk_pool_set_rxq_info(pool->xsk_pool, &cq->xdp_rxq);
+			} else if (pool->page_pool) {
+				xdp_rxq_info_reg_mem_model(&cq->xdp_rxq,
+							   MEM_TYPE_PAGE_POOL,
+							   pool->page_pool);
+			}
 		}
 	} else if (qidx < non_xdp_queues) {
 		cq->cq_type = CQ_TX;
@@ -1281,9 +1293,10 @@ void otx2_free_bufs(struct otx2_nic *pfvf, struct otx2_pool *pool,
 
 	pa = otx2_iova_to_phys(pfvf->iommu_domain, iova);
 	page = virt_to_head_page(phys_to_virt(pa));
-
 	if (pool->page_pool) {
 		page_pool_put_full_page(pool->page_pool, page, true);
+	} else if (pool->xsk_pool) {
+		/* Note: No way of identifying xdp_buff */
 	} else {
 		dma_unmap_page_attrs(pfvf->dev, iova, size,
 				     DMA_FROM_DEVICE,
@@ -1298,6 +1311,7 @@ void otx2_free_aura_ptr(struct otx2_nic *pfvf, int type)
 	int pool_id, pool_start = 0, pool_end = 0, size = 0;
 	struct otx2_pool *pool;
 	u64 iova;
+	int idx;
 
 	if (type == AURA_NIX_SQ) {
 		pool_start = otx2_get_pool_idx(pfvf, type, 0);
@@ -1312,16 +1326,21 @@ void otx2_free_aura_ptr(struct otx2_nic *pfvf, int type)
 
 	/* Free SQB and RQB pointers from the aura pool */
 	for (pool_id = pool_start; pool_id < pool_end; pool_id++) {
-		iova = otx2_aura_allocptr(pfvf, pool_id);
 		pool = &pfvf->qset.pool[pool_id];
+		iova = otx2_aura_allocptr(pfvf, pool_id);
 		while (iova) {
 			if (type == AURA_NIX_RQ)
 				iova -= OTX2_HEAD_ROOM;
-
 			otx2_free_bufs(pfvf, pool, iova, size);
-
 			iova = otx2_aura_allocptr(pfvf, pool_id);
 		}
+
+		for (idx = 0 ; idx < pool->xdp_cnt; idx++) {
+			if (!pool->xdp[idx])
+				continue;
+
+			xsk_buff_free(pool->xdp[idx]);
+		}
 	}
 }
 
@@ -1338,7 +1357,8 @@ void otx2_aura_pool_free(struct otx2_nic *pfvf)
 		qmem_free(pfvf->dev, pool->stack);
 		qmem_free(pfvf->dev, pool->fc_addr);
 		page_pool_destroy(pool->page_pool);
-		pool->page_pool = NULL;
+		devm_kfree(pfvf->dev, pool->xdp);
+		pool->xsk_pool = NULL;
 	}
 	devm_kfree(pfvf->dev, pfvf->qset.pool);
 	pfvf->qset.pool = NULL;
@@ -1425,6 +1445,7 @@ int otx2_pool_init(struct otx2_nic *pfvf, u16 pool_id,
 		   int stack_pages, int numptrs, int buf_size, int type)
 {
 	struct page_pool_params pp_params = { 0 };
+	struct xsk_buff_pool *xsk_pool;
 	struct npa_aq_enq_req *aq;
 	struct otx2_pool *pool;
 	int err;
@@ -1468,21 +1489,35 @@ int otx2_pool_init(struct otx2_nic *pfvf, u16 pool_id,
 	aq->ctype = NPA_AQ_CTYPE_POOL;
 	aq->op = NPA_AQ_INSTOP_INIT;
 
-	if (type != AURA_NIX_RQ) {
-		pool->page_pool = NULL;
+	if (type != AURA_NIX_RQ)
+		return 0;
+
+	if (!test_bit(pool_id, pfvf->af_xdp_zc_qidx)) {
+		pp_params.order = get_order(buf_size);
+		pp_params.flags = PP_FLAG_DMA_MAP;
+		pp_params.pool_size = min(OTX2_PAGE_POOL_SZ, numptrs);
+		pp_params.nid = NUMA_NO_NODE;
+		pp_params.dev = pfvf->dev;
+		pp_params.dma_dir = DMA_FROM_DEVICE;
+		pool->page_pool = page_pool_create(&pp_params);
+		if (IS_ERR(pool->page_pool)) {
+			netdev_err(pfvf->netdev, "Creation of page pool failed\n");
+			return PTR_ERR(pool->page_pool);
+		}
 		return 0;
 	}
 
-	pp_params.order = get_order(buf_size);
-	pp_params.flags = PP_FLAG_DMA_MAP;
-	pp_params.pool_size = min(OTX2_PAGE_POOL_SZ, numptrs);
-	pp_params.nid = NUMA_NO_NODE;
-	pp_params.dev = pfvf->dev;
-	pp_params.dma_dir = DMA_FROM_DEVICE;
-	pool->page_pool = page_pool_create(&pp_params);
-	if (IS_ERR(pool->page_pool)) {
-		netdev_err(pfvf->netdev, "Creation of page pool failed\n");
-		return PTR_ERR(pool->page_pool);
+	/* Set XSK pool to support AF_XDP zero-copy */
+	xsk_pool = xsk_get_pool_from_qid(pfvf->netdev, pool_id);
+	if (xsk_pool) {
+		pool->xsk_pool = xsk_pool;
+		pool->xdp_cnt = numptrs;
+		pool->xdp = devm_kcalloc(pfvf->dev,
+					 numptrs, sizeof(struct xdp_buff *), GFP_KERNEL);
+		if (IS_ERR(pool->xdp)) {
+			netdev_err(pfvf->netdev, "Creation of xsk pool failed\n");
+			return PTR_ERR(pool->xdp);
+		}
 	}
 
 	return 0;
@@ -1543,9 +1578,18 @@ int otx2_sq_aura_pool_init(struct otx2_nic *pfvf)
 		}
 
 		for (ptr = 0; ptr < num_sqbs; ptr++) {
-			err = otx2_alloc_rbuf(pfvf, pool, &bufptr);
-			if (err)
+			err = otx2_alloc_rbuf(pfvf, pool, &bufptr, pool_id, ptr);
+			if (err) {
+				if (pool->xsk_pool) {
+					ptr--;
+					while (ptr >= 0) {
+						xsk_buff_free(pool->xdp[ptr]);
+						ptr--;
+					}
+				}
 				goto err_mem;
+			}
+
 			pfvf->hw_ops->aura_freeptr(pfvf, pool_id, bufptr);
 			sq->sqb_ptrs[sq->sqb_count++] = (u64)bufptr;
 		}
@@ -1595,11 +1639,19 @@ int otx2_rq_aura_pool_init(struct otx2_nic *pfvf)
 	/* Allocate pointers and free them to aura/pool */
 	for (pool_id = 0; pool_id < hw->rqpool_cnt; pool_id++) {
 		pool = &pfvf->qset.pool[pool_id];
+
 		for (ptr = 0; ptr < num_ptrs; ptr++) {
-			err = otx2_alloc_rbuf(pfvf, pool, &bufptr);
-			if (err)
+			err = otx2_alloc_rbuf(pfvf, pool, &bufptr, pool_id, ptr);
+			if (err) {
+				if (pool->xsk_pool) {
+					while (ptr)
+						xsk_buff_free(pool->xdp[--ptr]);
+				}
 				return -ENOMEM;
+			}
+
 			pfvf->hw_ops->aura_freeptr(pfvf, pool_id,
+						   pool->xsk_pool ? bufptr :
 						   bufptr + OTX2_HEAD_ROOM);
 		}
 	}

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h

@@ -532,6 +532,8 @@ struct otx2_nic {
 
 	/* Inline ipsec */
 	struct cn10k_ipsec	ipsec;
+	/* af_xdp zero-copy */
+	unsigned long		*af_xdp_zc_qidx;
 };
 
 static inline bool is_otx2_lbkvf(struct pci_dev *pdev)
@@ -1003,7 +1005,7 @@ void otx2_txschq_free_one(struct otx2_nic *pfvf, u16 lvl, u16 schq);
 void otx2_free_pending_sqe(struct otx2_nic *pfvf);
 void otx2_sqb_flush(struct otx2_nic *pfvf);
 int otx2_alloc_rbuf(struct otx2_nic *pfvf, struct otx2_pool *pool,
-		    dma_addr_t *dma);
+		    dma_addr_t *dma, int qidx, int idx);
 int otx2_rxtx_enable(struct otx2_nic *pfvf, bool enable);
 void otx2_ctx_disable(struct mbox *mbox, int type, bool npa);
 int otx2_nix_config_bp(struct otx2_nic *pfvf, bool enable);
@@ -1033,6 +1035,8 @@ void otx2_pfaf_mbox_destroy(struct otx2_nic *pf);
 void otx2_disable_mbox_intr(struct otx2_nic *pf);
 void otx2_disable_napi(struct otx2_nic *pf);
 irqreturn_t otx2_cq_intr_handler(int irq, void *cq_irq);
+int otx2_rq_init(struct otx2_nic *pfvf, u16 qidx, u16 lpb_aura);
+int otx2_cq_init(struct otx2_nic *pfvf, u16 qidx);
 
 /* RSS configuration APIs*/
 int otx2_rss_init(struct otx2_nic *pfvf);

drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c

@@ -27,6 +27,7 @@
 #include "qos.h"
 #include <rvu_trace.h>
 #include "cn10k_ipsec.h"
+#include "otx2_xsk.h"
 
 #define DRV_NAME	"rvu_nicpf"
 #define DRV_STRING	"Marvell RVU NIC Physical Function Driver"
@@ -1662,9 +1663,7 @@ void otx2_free_hw_resources(struct otx2_nic *pf)
 	struct nix_lf_free_req *free_req;
 	struct mbox *mbox = &pf->mbox;
 	struct otx2_cq_queue *cq;
-	struct otx2_pool *pool;
 	struct msg_req *req;
-	int pool_id;
 	int qidx;
 
 	/* Ensure all SQE are processed */
@@ -1705,13 +1704,6 @@ void otx2_free_hw_resources(struct otx2_nic *pf)
 	/* Free RQ buffer pointers*/
 	otx2_free_aura_ptr(pf, AURA_NIX_RQ);
 
-	for (qidx = 0; qidx < pf->hw.rx_queues; qidx++) {
-		pool_id = otx2_get_pool_idx(pf, AURA_NIX_RQ, qidx);
-		pool = &pf->qset.pool[pool_id];
-		page_pool_destroy(pool->page_pool);
-		pool->page_pool = NULL;
-	}
-
 	otx2_free_cq_res(pf);
 
 	/* Free all ingress bandwidth profiles allocated */
@@ -2788,6 +2780,8 @@ static int otx2_xdp(struct net_device *netdev, struct netdev_bpf *xdp)
 	switch (xdp->command) {
 	case XDP_SETUP_PROG:
 		return otx2_xdp_setup(pf, xdp->prog);
+	case XDP_SETUP_XSK_POOL:
+		return otx2_xsk_pool_setup(pf, xdp->xsk.pool, xdp->xsk.queue_id);
 	default:
 		return -EINVAL;
 	}
@@ -2865,6 +2859,7 @@ static const struct net_device_ops otx2_netdev_ops = {
 	.ndo_set_vf_vlan	= otx2_set_vf_vlan,
 	.ndo_get_vf_config	= otx2_get_vf_config,
 	.ndo_bpf		= otx2_xdp,
+	.ndo_xsk_wakeup		= otx2_xsk_wakeup,
 	.ndo_xdp_xmit           = otx2_xdp_xmit,
 	.ndo_setup_tc		= otx2_setup_tc,
 	.ndo_set_vf_trust	= otx2_ndo_set_vf_trust,
@@ -3203,16 +3198,26 @@ static int otx2_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	/* Enable link notifications */
 	otx2_cgx_config_linkevents(pf, true);
 
+	pf->af_xdp_zc_qidx = bitmap_zalloc(qcount, GFP_KERNEL);
+	if (!pf->af_xdp_zc_qidx) {
+		err = -ENOMEM;
+		goto err_sriov_cleannup;
+	}
+
 #ifdef CONFIG_DCB
 	err = otx2_dcbnl_set_ops(netdev);
 	if (err)
-		goto err_pf_sriov_init;
+		goto err_free_zc_bmap;
 #endif
 
 	otx2_qos_init(pf, qos_txqs);
 
 	return 0;
 
+err_free_zc_bmap:
+	bitmap_free(pf->af_xdp_zc_qidx);
+err_sriov_cleannup:
+	otx2_sriov_vfcfg_cleanup(pf);
 err_pf_sriov_init:
 	otx2_shutdown_tc(pf);
 err_mcam_flow_del: