drivers/net/ethernet/intel/ice/ice_xsk.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019, Intel Corporation. */

#include <linux/bpf_trace.h>
#include <net/xdp_sock.h>
#include <net/xdp.h>
#include "ice.h"
#include "ice_base.h"
#include "ice_type.h"
#include "ice_xsk.h"
#include "ice_txrx.h"
#include "ice_txrx_lib.h"
#include "ice_lib.h"

/**
 * ice_qp_reset_stats - Resets all stats for rings of given index
 * @vsi: VSI that contains rings of interest
 * @q_idx: ring index in array
 */
static void ice_qp_reset_stats(struct ice_vsi *vsi, u16 q_idx)
{
	memset(&vsi->rx_rings[q_idx]->rx_stats, 0,
	       sizeof(vsi->rx_rings[q_idx]->rx_stats));
	memset(&vsi->tx_rings[q_idx]->stats, 0,
	       sizeof(vsi->tx_rings[q_idx]->stats));
	if (ice_is_xdp_ena_vsi(vsi))
		memset(&vsi->xdp_rings[q_idx]->stats, 0,
		       sizeof(vsi->xdp_rings[q_idx]->stats));
}

/**
 * ice_qp_clean_rings - Cleans all the rings of a given index
 * @vsi: VSI that contains rings of interest
 * @q_idx: ring index in array
 */
static void ice_qp_clean_rings(struct ice_vsi *vsi, u16 q_idx)
{
	ice_clean_tx_ring(vsi->tx_rings[q_idx]);
	if (ice_is_xdp_ena_vsi(vsi))
		ice_clean_tx_ring(vsi->xdp_rings[q_idx]);
	ice_clean_rx_ring(vsi->rx_rings[q_idx]);
}

/**
 * ice_qvec_toggle_napi - Enables/disables NAPI for a given q_vector
 * @vsi: VSI that has netdev
 * @q_vector: q_vector that has NAPI context
 * @enable: true for enable, false for disable
 */
static void
ice_qvec_toggle_napi(struct ice_vsi *vsi, struct ice_q_vector *q_vector,
		     bool enable)
{
	if (!vsi->netdev || !q_vector)
		return;

	if (enable)
		napi_enable(&q_vector->napi);
	else
		napi_disable(&q_vector->napi);
}

/**
 * ice_qvec_dis_irq - Mask off queue interrupt generation on given ring
 * @vsi: the VSI that contains queue vector being un-configured
 * @rx_ring: Rx ring that will have its IRQ disabled
 * @q_vector: queue vector
 */
static void
ice_qvec_dis_irq(struct ice_vsi *vsi, struct ice_ring *rx_ring,
		 struct ice_q_vector *q_vector)
{
	struct ice_pf *pf = vsi->back;
	struct ice_hw *hw = &pf->hw;
	int base = vsi->base_vector;
	u16 reg;
	u32 val;

	/* QINT_TQCTL is being cleared in ice_vsi_stop_tx_ring, so handle
	 * here only QINT_RQCTL
	 */
	reg = rx_ring->reg_idx;
	val = rd32(hw, QINT_RQCTL(reg));
	val &= ~QINT_RQCTL_CAUSE_ENA_M;
	wr32(hw, QINT_RQCTL(reg), val);

	if (q_vector) {
		u16 v_idx = q_vector->v_idx;

		wr32(hw, GLINT_DYN_CTL(q_vector->reg_idx), 0);
		ice_flush(hw);
		synchronize_irq(pf->msix_entries[v_idx + base].vector);
	}
}

/**
 * ice_qvec_cfg_msix - Enable IRQ for given queue vector
 * @vsi: the VSI that contains queue vector
 * @q_vector: queue vector
 */
static void
ice_qvec_cfg_msix(struct ice_vsi *vsi, struct ice_q_vector *q_vector)
{
	u16 reg_idx = q_vector->reg_idx;
	struct ice_pf *pf = vsi->back;
	struct ice_hw *hw = &pf->hw;
	struct ice_ring *ring;

	ice_cfg_itr(hw, q_vector);

	wr32(hw, GLINT_RATE(reg_idx),
	     ice_intrl_usec_to_reg(q_vector->intrl, hw->intrl_gran));

	ice_for_each_ring(ring, q_vector->tx)
		ice_cfg_txq_interrupt(vsi, ring->reg_idx, reg_idx,
				      q_vector->tx.itr_idx);

	ice_for_each_ring(ring, q_vector->rx)
		ice_cfg_rxq_interrupt(vsi, ring->reg_idx, reg_idx,
				      q_vector->rx.itr_idx);

	ice_flush(hw);
}

/**
 * ice_qvec_ena_irq - Enable IRQ for given queue vector
 * @vsi: the VSI that contains queue vector
 * @q_vector: queue vector
 */
static void ice_qvec_ena_irq(struct ice_vsi *vsi, struct ice_q_vector *q_vector)
{
	struct ice_pf *pf = vsi->back;
	struct ice_hw *hw = &pf->hw;

	ice_irq_dynamic_ena(hw, vsi, q_vector);

	ice_flush(hw);
}

/**
 * ice_qp_dis - Disables a queue pair
 * @vsi: VSI of interest
 * @q_idx: ring index in array
 *
 * Returns 0 on success, negative on failure.
 */
static int ice_qp_dis(struct ice_vsi *vsi, u16 q_idx)
{
	struct ice_txq_meta txq_meta = { };
	struct ice_ring *tx_ring, *rx_ring;
	struct ice_q_vector *q_vector;
	int timeout = 50;
	int err;

	if (q_idx >= vsi->num_rxq || q_idx >= vsi->num_txq)
		return -EINVAL;

	tx_ring = vsi->tx_rings[q_idx];
	rx_ring = vsi->rx_rings[q_idx];
	q_vector = rx_ring->q_vector;

	while (test_and_set_bit(__ICE_CFG_BUSY, vsi->state)) {
		timeout--;
		if (!timeout)
			return -EBUSY;
		usleep_range(1000, 2000);
	}
	netif_tx_stop_queue(netdev_get_tx_queue(vsi->netdev, q_idx));

	ice_qvec_dis_irq(vsi, rx_ring, q_vector);

	ice_fill_txq_meta(vsi, tx_ring, &txq_meta);
	err = ice_vsi_stop_tx_ring(vsi, ICE_NO_RESET, 0, tx_ring, &txq_meta);
	if (err)
		return err;
	if (ice_is_xdp_ena_vsi(vsi)) {
		struct ice_ring *xdp_ring = vsi->xdp_rings[q_idx];

		memset(&txq_meta, 0, sizeof(txq_meta));
		ice_fill_txq_meta(vsi, xdp_ring, &txq_meta);
		err = ice_vsi_stop_tx_ring(vsi, ICE_NO_RESET, 0, xdp_ring,
					   &txq_meta);
		if (err)
			return err;
	}
	err = ice_vsi_ctrl_rx_ring(vsi, false, q_idx);
	if (err)
		return err;

	ice_qvec_toggle_napi(vsi, q_vector, false);
	ice_qp_clean_rings(vsi, q_idx);
	ice_qp_reset_stats(vsi, q_idx);

	return 0;
}

/**
 * ice_qp_ena - Enables a queue pair
 * @vsi: VSI of interest
 * @q_idx: ring index in array
 *
 * Returns 0 on success, negative on failure.
 */
static int ice_qp_ena(struct ice_vsi *vsi, u16 q_idx)
{
	struct ice_aqc_add_tx_qgrp *qg_buf;
	struct ice_ring *tx_ring, *rx_ring;
	struct ice_q_vector *q_vector;
	int err;

	if (q_idx >= vsi->num_rxq || q_idx >= vsi->num_txq)
		return -EINVAL;

	qg_buf = kzalloc(sizeof(*qg_buf), GFP_KERNEL);
	if (!qg_buf)
		return -ENOMEM;

	qg_buf->num_txqs = 1;

	tx_ring = vsi->tx_rings[q_idx];
	rx_ring = vsi->rx_rings[q_idx];
	q_vector = rx_ring->q_vector;

	err = ice_vsi_cfg_txq(vsi, tx_ring, qg_buf);
	if (err)
		goto free_buf;

	if (ice_is_xdp_ena_vsi(vsi)) {
		struct ice_ring *xdp_ring = vsi->xdp_rings[q_idx];

		memset(qg_buf, 0, sizeof(*qg_buf));
		qg_buf->num_txqs = 1;
		err = ice_vsi_cfg_txq(vsi, xdp_ring, qg_buf);
		if (err)
			goto free_buf;
		ice_set_ring_xdp(xdp_ring);
		xdp_ring->xsk_umem = ice_xsk_umem(xdp_ring);
	}

	err = ice_setup_rx_ctx(rx_ring);
	if (err)
		goto free_buf;

	ice_qvec_cfg_msix(vsi, q_vector);

	err = ice_vsi_ctrl_rx_ring(vsi, true, q_idx);
	if (err)
		goto free_buf;

	clear_bit(__ICE_CFG_BUSY, vsi->state);
	ice_qvec_toggle_napi(vsi, q_vector, true);
	ice_qvec_ena_irq(vsi, q_vector);

	netif_tx_start_queue(netdev_get_tx_queue(vsi->netdev, q_idx));
free_buf:
	kfree(qg_buf);
	return err;
}

/**
 * ice_xsk_alloc_umems - allocate a UMEM region for an XDP socket
 * @vsi: VSI to allocate the UMEM on
 *
 * Returns 0 on success, negative on error
 */
static int ice_xsk_alloc_umems(struct ice_vsi *vsi)
{
	if (vsi->xsk_umems)
		return 0;

	vsi->xsk_umems = kcalloc(vsi->num_xsk_umems, sizeof(*vsi->xsk_umems),
				 GFP_KERNEL);

	if (!vsi->xsk_umems) {
		vsi->num_xsk_umems = 0;
		return -ENOMEM;
	}

	return 0;
}

/**
 * ice_xsk_add_umem - add a UMEM region for XDP sockets
 * @vsi: VSI to which the UMEM will be added
 * @umem: pointer to a requested UMEM region
 * @qid: queue ID
 *
 * Returns 0 on success, negative on error
 */
static int ice_xsk_add_umem(struct ice_vsi *vsi, struct xdp_umem *umem, u16 qid)
{
	int err;

	err = ice_xsk_alloc_umems(vsi);
	if (err)
		return err;

	vsi->xsk_umems[qid] = umem;
	vsi->num_xsk_umems_used++;

	return 0;
}

/**
 * ice_xsk_remove_umem - Remove an UMEM for a certain ring/qid
 * @vsi: VSI from which the VSI will be removed
 * @qid: Ring/qid associated with the UMEM
 */
static void ice_xsk_remove_umem(struct ice_vsi *vsi, u16 qid)
{
	vsi->xsk_umems[qid] = NULL;
	vsi->num_xsk_umems_used--;

	if (vsi->num_xsk_umems_used == 0) {
		kfree(vsi->xsk_umems);
		vsi->xsk_umems = NULL;
		vsi->num_xsk_umems = 0;
	}
}

/**
 * ice_xsk_umem_dma_map - DMA map UMEM region for XDP sockets
 * @vsi: VSI to map the UMEM region
 * @umem: UMEM to map
 *
 * Returns 0 on success, negative on error
 */
static int ice_xsk_umem_dma_map(struct ice_vsi *vsi, struct xdp_umem *umem)
{
	struct ice_pf *pf = vsi->back;
	struct device *dev;
	unsigned int i;

	dev = ice_pf_to_dev(pf);
	for (i = 0; i < umem->npgs; i++) {
		dma_addr_t dma = dma_map_page_attrs(dev, umem->pgs[i], 0,
						    PAGE_SIZE,
						    DMA_BIDIRECTIONAL,
						    ICE_RX_DMA_ATTR);
		if (dma_mapping_error(dev, dma)) {
			dev_dbg(dev,
				"XSK UMEM DMA mapping error on page num %d", i);
			goto out_unmap;
		}

		umem->pages[i].dma = dma;
	}

	return 0;

out_unmap:
	for (; i > 0; i--) {
		dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE,
				     DMA_BIDIRECTIONAL, ICE_RX_DMA_ATTR);
		umem->pages[i].dma = 0;
	}

	return -EFAULT;
}

/**
 * ice_xsk_umem_dma_unmap - DMA unmap UMEM region for XDP sockets
 * @vsi: VSI from which the UMEM will be unmapped
 * @umem: UMEM to unmap
 */
static void ice_xsk_umem_dma_unmap(struct ice_vsi *vsi, struct xdp_umem *umem)
{
	struct ice_pf *pf = vsi->back;
	struct device *dev;
	unsigned int i;

	dev = ice_pf_to_dev(pf);
	for (i = 0; i < umem->npgs; i++) {
		dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE,
				     DMA_BIDIRECTIONAL, ICE_RX_DMA_ATTR);

		umem->pages[i].dma = 0;
	}
}

/**
 * ice_xsk_umem_disable - disable a UMEM region
 * @vsi: Current VSI
 * @qid: queue ID
 *
 * Returns 0 on success, negative on failure
 */
static int ice_xsk_umem_disable(struct ice_vsi *vsi, u16 qid)
{
	if (!vsi->xsk_umems || qid >= vsi->num_xsk_umems ||
	    !vsi->xsk_umems[qid])
		return -EINVAL;

	ice_xsk_umem_dma_unmap(vsi, vsi->xsk_umems[qid]);
	ice_xsk_remove_umem(vsi, qid);

	return 0;
}

/**
 * ice_xsk_umem_enable - enable a UMEM region
 * @vsi: Current VSI
 * @umem: pointer to a requested UMEM region
 * @qid: queue ID
 *
 * Returns 0 on success, negative on failure
 */
static int
ice_xsk_umem_enable(struct ice_vsi *vsi, struct xdp_umem *umem, u16 qid)
{
	struct xdp_umem_fq_reuse *reuseq;
	int err;

	if (vsi->type != ICE_VSI_PF)
		return -EINVAL;

	vsi->num_xsk_umems = min_t(u16, vsi->num_rxq, vsi->num_txq);
	if (qid >= vsi->num_xsk_umems)
		return -EINVAL;

	if (vsi->xsk_umems && vsi->xsk_umems[qid])
		return -EBUSY;

	reuseq = xsk_reuseq_prepare(vsi->rx_rings[0]->count);
	if (!reuseq)
		return -ENOMEM;

	xsk_reuseq_free(xsk_reuseq_swap(umem, reuseq));

	err = ice_xsk_umem_dma_map(vsi, umem);
	if (err)
		return err;

	err = ice_xsk_add_umem(vsi, umem, qid);
	if (err)
		return err;

	return 0;
}

/**
 * ice_xsk_umem_setup - enable/disable a UMEM region depending on its state
 * @vsi: Current VSI
 * @umem: UMEM to enable/associate to a ring, NULL to disable
 * @qid: queue ID
 *
 * Returns 0 on success, negative on failure
 */
int ice_xsk_umem_setup(struct ice_vsi *vsi, struct xdp_umem *umem, u16 qid)
{
	bool if_running, umem_present = !!umem;
	int ret = 0, umem_failure = 0;

	if_running = netif_running(vsi->netdev) && ice_is_xdp_ena_vsi(vsi);

	if (if_running) {
		ret = ice_qp_dis(vsi, qid);
		if (ret) {
			netdev_err(vsi->netdev, "ice_qp_dis error = %d", ret);
			goto xsk_umem_if_up;
		}
	}

	umem_failure = umem_present ? ice_xsk_umem_enable(vsi, umem, qid) :
				      ice_xsk_umem_disable(vsi, qid);

xsk_umem_if_up:
	if (if_running) {
		ret = ice_qp_ena(vsi, qid);
		if (!ret && umem_present)
			napi_schedule(&vsi->xdp_rings[qid]->q_vector->napi);
		else if (ret)
			netdev_err(vsi->netdev, "ice_qp_ena error = %d", ret);
	}

	if (umem_failure) {
		netdev_err(vsi->netdev, "Could not %sable UMEM, error = %d",
			   umem_present ? "en" : "dis", umem_failure);
		return umem_failure;
	}

	return ret;
}

/**
 * ice_zca_free - Callback for MEM_TYPE_ZERO_COPY allocations
 * @zca: zero-cpoy allocator
 * @handle: Buffer handle
 */
void ice_zca_free(struct zero_copy_allocator *zca, unsigned long handle)
{
	struct ice_rx_buf *rx_buf;
	struct ice_ring *rx_ring;
	struct xdp_umem *umem;
	u64 hr, mask;
	u16 nta;

	rx_ring = container_of(zca, struct ice_ring, zca);
	umem = rx_ring->xsk_umem;
	hr = umem->headroom + XDP_PACKET_HEADROOM;

	mask = umem->chunk_mask;

	nta = rx_ring->next_to_alloc;
	rx_buf = &rx_ring->rx_buf[nta];

	nta++;
	rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;

	handle &= mask;

	rx_buf->dma = xdp_umem_get_dma(umem, handle);
	rx_buf->dma += hr;

	rx_buf->addr = xdp_umem_get_data(umem, handle);
	rx_buf->addr += hr;

	rx_buf->handle = (u64)handle + umem->headroom;
}

/**
 * ice_alloc_buf_fast_zc - Retrieve buffer address from XDP umem
 * @rx_ring: ring with an xdp_umem bound to it
 * @rx_buf: buffer to which xsk page address will be assigned
 *
 * This function allocates an Rx buffer in the hot path.
 * The buffer can come from fill queue or recycle queue.
 *
 * Returns true if an assignment was successful, false if not.
 */
static __always_inline bool
ice_alloc_buf_fast_zc(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf)
{
	struct xdp_umem *umem = rx_ring->xsk_umem;
	void *addr = rx_buf->addr;
	u64 handle, hr;

	if (addr) {
		rx_ring->rx_stats.page_reuse_count++;
		return true;
	}

	if (!xsk_umem_peek_addr(umem, &handle)) {
		rx_ring->rx_stats.alloc_page_failed++;
		return false;
	}

	hr = umem->headroom + XDP_PACKET_HEADROOM;

	rx_buf->dma = xdp_umem_get_dma(umem, handle);
	rx_buf->dma += hr;

	rx_buf->addr = xdp_umem_get_data(umem, handle);
	rx_buf->addr += hr;

	rx_buf->handle = handle + umem->headroom;

	xsk_umem_discard_addr(umem);
	return true;
}

/**
 * ice_alloc_buf_slow_zc - Retrieve buffer address from XDP umem
 * @rx_ring: ring with an xdp_umem bound to it
 * @rx_buf: buffer to which xsk page address will be assigned
 *
 * This function allocates an Rx buffer in the slow path.
 * The buffer can come from fill queue or recycle queue.
 *
 * Returns true if an assignment was successful, false if not.
 */
static __always_inline bool
ice_alloc_buf_slow_zc(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf)
{
	struct xdp_umem *umem = rx_ring->xsk_umem;
	u64 handle, headroom;

	if (!xsk_umem_peek_addr_rq(umem, &handle)) {
		rx_ring->rx_stats.alloc_page_failed++;
		return false;
	}

	handle &= umem->chunk_mask;
	headroom = umem->headroom + XDP_PACKET_HEADROOM;

	rx_buf->dma = xdp_umem_get_dma(umem, handle);
	rx_buf->dma += headroom;

	rx_buf->addr = xdp_umem_get_data(umem, handle);
	rx_buf->addr += headroom;

	rx_buf->handle = handle + umem->headroom;

	xsk_umem_discard_addr_rq(umem);
	return true;
}

/**
 * ice_alloc_rx_bufs_zc - allocate a number of Rx buffers
 * @rx_ring: Rx ring
 * @count: The number of buffers to allocate
 * @alloc: the function pointer to call for allocation
 *
 * This function allocates a number of Rx buffers from the fill ring
 * or the internal recycle mechanism and places them on the Rx ring.
 *
 * Returns false if all allocations were successful, true if any fail.
 */
static bool
ice_alloc_rx_bufs_zc(struct ice_ring *rx_ring, int count,
		     bool alloc(struct ice_ring *, struct ice_rx_buf *))
{
	union ice_32b_rx_flex_desc *rx_desc;
	u16 ntu = rx_ring->next_to_use;
	struct ice_rx_buf *rx_buf;
	bool ret = false;

	if (!count)
		return false;

	rx_desc = ICE_RX_DESC(rx_ring, ntu);
	rx_buf = &rx_ring->rx_buf[ntu];

	do {
		if (!alloc(rx_ring, rx_buf)) {
			ret = true;
			break;
		}

		dma_sync_single_range_for_device(rx_ring->dev, rx_buf->dma, 0,
						 rx_ring->rx_buf_len,
						 DMA_BIDIRECTIONAL);

		rx_desc->read.pkt_addr = cpu_to_le64(rx_buf->dma);
		rx_desc->wb.status_error0 = 0;

		rx_desc++;
		rx_buf++;
		ntu++;

		if (unlikely(ntu == rx_ring->count)) {
			rx_desc = ICE_RX_DESC(rx_ring, 0);
			rx_buf = rx_ring->rx_buf;
			ntu = 0;
		}
	} while (--count);

	if (rx_ring->next_to_use != ntu)
		ice_release_rx_desc(rx_ring, ntu);

	return ret;
}

/**
 * ice_alloc_rx_bufs_fast_zc - allocate zero copy bufs in the hot path
 * @rx_ring: Rx ring
 * @count: number of bufs to allocate
 *
 * Returns false on success, true on failure.
 */
static bool ice_alloc_rx_bufs_fast_zc(struct ice_ring *rx_ring, u16 count)
{
	return ice_alloc_rx_bufs_zc(rx_ring, count,
				    ice_alloc_buf_fast_zc);
}

/**
 * ice_alloc_rx_bufs_slow_zc - allocate zero copy bufs in the slow path
 * @rx_ring: Rx ring
 * @count: number of bufs to allocate
 *
 * Returns false on success, true on failure.
 */
bool ice_alloc_rx_bufs_slow_zc(struct ice_ring *rx_ring, u16 count)
{
	return ice_alloc_rx_bufs_zc(rx_ring, count,
				    ice_alloc_buf_slow_zc);
}

/**
 * ice_bump_ntc - Bump the next_to_clean counter of an Rx ring
 * @rx_ring: Rx ring
 */
static void ice_bump_ntc(struct ice_ring *rx_ring)
{
	int ntc = rx_ring->next_to_clean + 1;

	ntc = (ntc < rx_ring->count) ? ntc : 0;
	rx_ring->next_to_clean = ntc;
	prefetch(ICE_RX_DESC(rx_ring, ntc));
}

/**
 * ice_get_rx_buf_zc - Fetch the current Rx buffer
 * @rx_ring: Rx ring
 * @size: size of a buffer
 *
 * This function returns the current, received Rx buffer and does
 * DMA synchronization.
 *
 * Returns a pointer to the received Rx buffer.
 */
static struct ice_rx_buf *ice_get_rx_buf_zc(struct ice_ring *rx_ring, int size)
{
	struct ice_rx_buf *rx_buf;

	rx_buf = &rx_ring->rx_buf[rx_ring->next_to_clean];

	dma_sync_single_range_for_cpu(rx_ring->dev, rx_buf->dma, 0,
				      size, DMA_BIDIRECTIONAL);

	return rx_buf;
}

/**
 * ice_reuse_rx_buf_zc - reuse an Rx buffer
 * @rx_ring: Rx ring
 * @old_buf: The buffer to recycle
 *
 * This function recycles a finished Rx buffer, and places it on the recycle
 * queue (next_to_alloc).
 */
static void
ice_reuse_rx_buf_zc(struct ice_ring *rx_ring, struct ice_rx_buf *old_buf)
{
	unsigned long mask = (unsigned long)rx_ring->xsk_umem->chunk_mask;
	u64 hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM;
	u16 nta = rx_ring->next_to_alloc;
	struct ice_rx_buf *new_buf;

	new_buf = &rx_ring->rx_buf[nta++];
	rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;

	new_buf->dma = old_buf->dma & mask;
	new_buf->dma += hr;

	new_buf->addr = (void *)((unsigned long)old_buf->addr & mask);
	new_buf->addr += hr;

	new_buf->handle = old_buf->handle & mask;
	new_buf->handle += rx_ring->xsk_umem->headroom;

	old_buf->addr = NULL;
}

/**
 * ice_construct_skb_zc - Create an sk_buff from zero-copy buffer
 * @rx_ring: Rx ring
 * @rx_buf: zero-copy Rx buffer
 * @xdp: XDP buffer
 *
 * This function allocates a new skb from a zero-copy Rx buffer.
 *
 * Returns the skb on success, NULL on failure.
 */
static struct sk_buff *
ice_construct_skb_zc(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf,
		     struct xdp_buff *xdp)
{
	unsigned int metasize = xdp->data - xdp->data_meta;
	unsigned int datasize = xdp->data_end - xdp->data;
	unsigned int datasize_hard = xdp->data_end -
				     xdp->data_hard_start;
	struct sk_buff *skb;

	skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize_hard,
			       GFP_ATOMIC | __GFP_NOWARN);
	if (unlikely(!skb))
		return NULL;

	skb_reserve(skb, xdp->data - xdp->data_hard_start);
	memcpy(__skb_put(skb, datasize), xdp->data, datasize);
	if (metasize)
		skb_metadata_set(skb, metasize);

	ice_reuse_rx_buf_zc(rx_ring, rx_buf);

	return skb;
}

/**
 * ice_run_xdp_zc - Executes an XDP program in zero-copy path
 * @rx_ring: Rx ring
 * @xdp: xdp_buff used as input to the XDP program
 *
 * Returns any of ICE_XDP_{PASS, CONSUMED, TX, REDIR}
 */
static int
ice_run_xdp_zc(struct ice_ring *rx_ring, struct xdp_buff *xdp)
{
	int err, result = ICE_XDP_PASS;
	struct bpf_prog *xdp_prog;
	struct ice_ring *xdp_ring;
	u32 act;

	rcu_read_lock();
	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
	if (!xdp_prog) {
		rcu_read_unlock();
		return ICE_XDP_PASS;
	}

	act = bpf_prog_run_xdp(xdp_prog, xdp);
	xdp->handle += xdp->data - xdp->data_hard_start;
	switch (act) {
	case XDP_PASS:
		break;
	case XDP_TX:
		xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->q_index];
		result = ice_xmit_xdp_buff(xdp, xdp_ring);
		break;
	case XDP_REDIRECT:
		err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
		result = !err ? ICE_XDP_REDIR : ICE_XDP_CONSUMED;
		break;
	default:
		bpf_warn_invalid_xdp_action(act);
		/* fallthrough -- not supported action */
	case XDP_ABORTED:
		trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
		/* fallthrough -- handle aborts by dropping frame */
	case XDP_DROP:
		result = ICE_XDP_CONSUMED;
		break;
	}

	rcu_read_unlock();
	return result;
}

/**
 * ice_clean_rx_irq_zc - consumes packets from the hardware ring
 * @rx_ring: AF_XDP Rx ring
 * @budget: NAPI budget
 *
 * Returns number of processed packets on success, remaining budget on failure.
 */
int ice_clean_rx_irq_zc(struct ice_ring *rx_ring, int budget)
{
	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
	u16 cleaned_count = ICE_DESC_UNUSED(rx_ring);
	unsigned int xdp_xmit = 0;
	struct xdp_buff xdp;
	bool failure = 0;

	xdp.rxq = &rx_ring->xdp_rxq;

	while (likely(total_rx_packets < (unsigned int)budget)) {
		union ice_32b_rx_flex_desc *rx_desc;
		unsigned int size, xdp_res = 0;
		struct ice_rx_buf *rx_buf;
		struct sk_buff *skb;
		u16 stat_err_bits;
		u16 vlan_tag = 0;
		u8 rx_ptype;

		if (cleaned_count >= ICE_RX_BUF_WRITE) {
			failure |= ice_alloc_rx_bufs_fast_zc(rx_ring,
							     cleaned_count);
			cleaned_count = 0;
		}

		rx_desc = ICE_RX_DESC(rx_ring, rx_ring->next_to_clean);

		stat_err_bits = BIT(ICE_RX_FLEX_DESC_STATUS0_DD_S);
		if (!ice_test_staterr(rx_desc, stat_err_bits))
			break;

		/* This memory barrier is needed to keep us from reading
		 * any other fields out of the rx_desc until we have
		 * verified the descriptor has been written back.
		 */
		dma_rmb();

		size = le16_to_cpu(rx_desc->wb.pkt_len) &
				   ICE_RX_FLX_DESC_PKT_LEN_M;
		if (!size)
			break;

		rx_buf = ice_get_rx_buf_zc(rx_ring, size);
		if (!rx_buf->addr)
			break;

		xdp.data = rx_buf->addr;
		xdp.data_meta = xdp.data;
		xdp.data_hard_start = xdp.data - XDP_PACKET_HEADROOM;
		xdp.data_end = xdp.data + size;
		xdp.handle = rx_buf->handle;

		xdp_res = ice_run_xdp_zc(rx_ring, &xdp);
		if (xdp_res) {
			if (xdp_res & (ICE_XDP_TX | ICE_XDP_REDIR)) {
				xdp_xmit |= xdp_res;
				rx_buf->addr = NULL;
			} else {
				ice_reuse_rx_buf_zc(rx_ring, rx_buf);
			}

			total_rx_bytes += size;
			total_rx_packets++;
			cleaned_count++;

			ice_bump_ntc(rx_ring);
			continue;
		}

		/* XDP_PASS path */
		skb = ice_construct_skb_zc(rx_ring, rx_buf, &xdp);
		if (!skb) {
			rx_ring->rx_stats.alloc_buf_failed++;
			break;
		}

		cleaned_count++;
		ice_bump_ntc(rx_ring);

		if (eth_skb_pad(skb)) {
			skb = NULL;
			continue;
		}

		total_rx_bytes += skb->len;
		total_rx_packets++;

		stat_err_bits = BIT(ICE_RX_FLEX_DESC_STATUS0_L2TAG1P_S);
		if (ice_test_staterr(rx_desc, stat_err_bits))
			vlan_tag = le16_to_cpu(rx_desc->wb.l2tag1);

		rx_ptype = le16_to_cpu(rx_desc->wb.ptype_flex_flags0) &
				       ICE_RX_FLEX_DESC_PTYPE_M;

		ice_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype);
		ice_receive_skb(rx_ring, skb, vlan_tag);
	}

	ice_finalize_xdp_rx(rx_ring, xdp_xmit);
	ice_update_rx_ring_stats(rx_ring, total_rx_packets, total_rx_bytes);

	return failure ? budget : (int)total_rx_packets;
}

/**
 * ice_xmit_zc - Completes AF_XDP entries, and cleans XDP entries
 * @xdp_ring: XDP Tx ring
 * @budget: max number of frames to xmit
 *
 * Returns true if cleanup/transmission is done.
 */
static bool ice_xmit_zc(struct ice_ring *xdp_ring, int budget)
{
	struct ice_tx_desc *tx_desc = NULL;
	bool work_done = true;
	struct xdp_desc desc;
	dma_addr_t dma;

	while (likely(budget-- > 0)) {
		struct ice_tx_buf *tx_buf;

		if (unlikely(!ICE_DESC_UNUSED(xdp_ring))) {
			xdp_ring->tx_stats.tx_busy++;
			work_done = false;
			break;
		}

		tx_buf = &xdp_ring->tx_buf[xdp_ring->next_to_use];

		if (!xsk_umem_consume_tx(xdp_ring->xsk_umem, &desc))
			break;

		dma = xdp_umem_get_dma(xdp_ring->xsk_umem, desc.addr);

		dma_sync_single_for_device(xdp_ring->dev, dma, desc.len,
					   DMA_BIDIRECTIONAL);

		tx_buf->bytecount = desc.len;

		tx_desc = ICE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
		tx_desc->buf_addr = cpu_to_le64(dma);
		tx_desc->cmd_type_offset_bsz = build_ctob(ICE_TXD_LAST_DESC_CMD,
							  0, desc.len, 0);

		xdp_ring->next_to_use++;
		if (xdp_ring->next_to_use == xdp_ring->count)
			xdp_ring->next_to_use = 0;
	}

	if (tx_desc) {
		ice_xdp_ring_update_tail(xdp_ring);
		xsk_umem_consume_tx_done(xdp_ring->xsk_umem);
	}

	return budget > 0 && work_done;
}

/**
 * ice_clean_xdp_tx_buf - Free and unmap XDP Tx buffer
 * @xdp_ring: XDP Tx ring
 * @tx_buf: Tx buffer to clean
 */
static void
ice_clean_xdp_tx_buf(struct ice_ring *xdp_ring, struct ice_tx_buf *tx_buf)
{
	xdp_return_frame((struct xdp_frame *)tx_buf->raw_buf);
	dma_unmap_single(xdp_ring->dev, dma_unmap_addr(tx_buf, dma),
			 dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);
	dma_unmap_len_set(tx_buf, len, 0);
}

/**
 * ice_clean_tx_irq_zc - Completes AF_XDP entries, and cleans XDP entries
 * @xdp_ring: XDP Tx ring
 * @budget: NAPI budget
 *
 * Returns true if cleanup/tranmission is done.
 */
bool ice_clean_tx_irq_zc(struct ice_ring *xdp_ring, int budget)
{
	int total_packets = 0, total_bytes = 0;
	s16 ntc = xdp_ring->next_to_clean;
	struct ice_tx_desc *tx_desc;
	struct ice_tx_buf *tx_buf;
	bool xmit_done = true;
	u32 xsk_frames = 0;

	tx_desc = ICE_TX_DESC(xdp_ring, ntc);
	tx_buf = &xdp_ring->tx_buf[ntc];
	ntc -= xdp_ring->count;

	do {
		if (!(tx_desc->cmd_type_offset_bsz &
		      cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE)))
			break;

		total_bytes += tx_buf->bytecount;
		total_packets++;

		if (tx_buf->raw_buf) {
			ice_clean_xdp_tx_buf(xdp_ring, tx_buf);
			tx_buf->raw_buf = NULL;
		} else {
			xsk_frames++;
		}

		tx_desc->cmd_type_offset_bsz = 0;
		tx_buf++;
		tx_desc++;
		ntc++;

		if (unlikely(!ntc)) {
			ntc -= xdp_ring->count;
			tx_buf = xdp_ring->tx_buf;
			tx_desc = ICE_TX_DESC(xdp_ring, 0);
		}

		prefetch(tx_desc);

	} while (likely(--budget));

	ntc += xdp_ring->count;
	xdp_ring->next_to_clean = ntc;

	if (xsk_frames)
		xsk_umem_complete_tx(xdp_ring->xsk_umem, xsk_frames);

	ice_update_tx_ring_stats(xdp_ring, total_packets, total_bytes);
	xmit_done = ice_xmit_zc(xdp_ring, ICE_DFLT_IRQ_WORK);

	return budget > 0 && xmit_done;
}

/**
 * ice_xsk_wakeup - Implements ndo_xsk_wakeup
 * @netdev: net_device
 * @queue_id: queue to wake up
 * @flags: ignored in our case, since we have Rx and Tx in the same NAPI
 *
 * Returns negative on error, zero otherwise.
 */
int
ice_xsk_wakeup(struct net_device *netdev, u32 queue_id,
	       u32 __always_unused flags)
{
	struct ice_netdev_priv *np = netdev_priv(netdev);
	struct ice_q_vector *q_vector;
	struct ice_vsi *vsi = np->vsi;
	struct ice_ring *ring;

	if (test_bit(__ICE_DOWN, vsi->state))
		return -ENETDOWN;

	if (!ice_is_xdp_ena_vsi(vsi))
		return -ENXIO;

	if (queue_id >= vsi->num_txq)
		return -ENXIO;

	if (!vsi->xdp_rings[queue_id]->xsk_umem)
		return -ENXIO;

	ring = vsi->xdp_rings[queue_id];

	/* The idea here is that if NAPI is running, mark a miss, so
	 * it will run again. If not, trigger an interrupt and
	 * schedule the NAPI from interrupt context. If NAPI would be
	 * scheduled here, the interrupt affinity would not be
	 * honored.
	 */
	q_vector = ring->q_vector;
	if (!napi_if_scheduled_mark_missed(&q_vector->napi))
		ice_trigger_sw_intr(&vsi->back->hw, q_vector);

	return 0;
}

/**
 * ice_xsk_any_rx_ring_ena - Checks if Rx rings have AF_XDP UMEM attached
 * @vsi: VSI to be checked
 *
 * Returns true if any of the Rx rings has an AF_XDP UMEM attached
 */
bool ice_xsk_any_rx_ring_ena(struct ice_vsi *vsi)
{
	int i;

	if (!vsi->xsk_umems)
		return false;

	for (i = 0; i < vsi->num_xsk_umems; i++) {
		if (vsi->xsk_umems[i])
			return true;
	}

	return false;
}

/**
 * ice_xsk_clean_rx_ring - clean UMEM queues connected to a given Rx ring
 * @rx_ring: ring to be cleaned
 */
void ice_xsk_clean_rx_ring(struct ice_ring *rx_ring)
{
	u16 i;

	for (i = 0; i < rx_ring->count; i++) {
		struct ice_rx_buf *rx_buf = &rx_ring->rx_buf[i];

		if (!rx_buf->addr)
			continue;

		xsk_umem_fq_reuse(rx_ring->xsk_umem, rx_buf->handle);
		rx_buf->addr = NULL;
	}
}

/**
 * ice_xsk_clean_xdp_ring - Clean the XDP Tx ring and its UMEM queues
 * @xdp_ring: XDP_Tx ring
 */
void ice_xsk_clean_xdp_ring(struct ice_ring *xdp_ring)
{
	u16 ntc = xdp_ring->next_to_clean, ntu = xdp_ring->next_to_use;
	u32 xsk_frames = 0;

	while (ntc != ntu) {
		struct ice_tx_buf *tx_buf = &xdp_ring->tx_buf[ntc];

		if (tx_buf->raw_buf)
			ice_clean_xdp_tx_buf(xdp_ring, tx_buf);
		else
			xsk_frames++;

		tx_buf->raw_buf = NULL;

		ntc++;
		if (ntc >= xdp_ring->count)
			ntc = 0;
	}

	if (xsk_frames)
		xsk_umem_complete_tx(xdp_ring->xsk_umem, xsk_frames);
}