drivers/net/ethernet/intel/ice/ice_txrx_lib.c - linux - Git at Google

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

 #include "ice_txrx_lib.h"

 /**
  * ice_release_rx_desc - Store the new tail and head values
  * @rx_ring: ring to bump
  * @val: new head index
  */
 void ice_release_rx_desc(struct ice_ring *rx_ring, u16 val)
 {
 	u16 prev_ntu = rx_ring->next_to_use & ~0x7;

 	rx_ring->next_to_use = val;

 	/* update next to alloc since we have filled the ring */
 	rx_ring->next_to_alloc = val;

 	/* QRX_TAIL will be updated with any tail value, but hardware ignores
 	 * the lower 3 bits. This makes it so we only bump tail on meaningful
 	 * boundaries. Also, this allows us to bump tail on intervals of 8 up to
 	 * the budget depending on the current traffic load.
 	 */
 	val &= ~0x7;
 	if (prev_ntu != val) {
 		/* Force memory writes to complete before letting h/w
 		 * know there are new descriptors to fetch. (Only
 		 * applicable for weak-ordered memory model archs,
 		 * such as IA-64).
 		 */
 		wmb();
 		writel(val, rx_ring->tail);
 	}
 }

 /**
  * ice_ptype_to_htype - get a hash type
  * @ptype: the ptype value from the descriptor
  *
  * Returns appropriate hash type (such as PKT_HASH_TYPE_L2/L3/L4) to be used by
  * skb_set_hash based on PTYPE as parsed by HW Rx pipeline and is part of
  * Rx desc.
  */
 static enum pkt_hash_types ice_ptype_to_htype(u16 ptype)
 {
 	struct ice_rx_ptype_decoded decoded = ice_decode_rx_desc_ptype(ptype);

 	if (!decoded.known)
 		return PKT_HASH_TYPE_NONE;
 	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY4)
 		return PKT_HASH_TYPE_L4;
 	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY3)
 		return PKT_HASH_TYPE_L3;
 	if (decoded.outer_ip == ICE_RX_PTYPE_OUTER_L2)
 		return PKT_HASH_TYPE_L2;

 	return PKT_HASH_TYPE_NONE;
 }

 /**
  * ice_rx_hash - set the hash value in the skb
  * @rx_ring: descriptor ring
  * @rx_desc: specific descriptor
  * @skb: pointer to current skb
  * @rx_ptype: the ptype value from the descriptor
  */
 static void
 ice_rx_hash(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
 	    struct sk_buff *skb, u16 rx_ptype)
 {
 	struct ice_32b_rx_flex_desc_nic *nic_mdid;
 	u32 hash;

 	if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
 		return;

 	if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
 		return;

 	nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
 	hash = le32_to_cpu(nic_mdid->rss_hash);
 	skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
 }

 /**
  * ice_rx_csum - Indicate in skb if checksum is good
  * @ring: the ring we care about
  * @skb: skb currently being received and modified
  * @rx_desc: the receive descriptor
  * @ptype: the packet type decoded by hardware
  *
  * skb->protocol must be set before this function is called
  */
 static void
 ice_rx_csum(struct ice_ring *ring, struct sk_buff *skb,
 	    union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
 {
 	struct ice_rx_ptype_decoded decoded;
 	u16 rx_status0, rx_status1;
 	bool ipv4, ipv6;

 	rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
 	rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);

 	decoded = ice_decode_rx_desc_ptype(ptype);

 	/* Start with CHECKSUM_NONE and by default csum_level = 0 */
 	skb->ip_summed = CHECKSUM_NONE;
 	skb_checksum_none_assert(skb);

 	/* check if Rx checksum is enabled */
 	if (!(ring->netdev->features & NETIF_F_RXCSUM))
 		return;

 	/* check if HW has decoded the packet and checksum */
 	if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
 		return;

 	if (!(decoded.known && decoded.outer_ip))
 		return;

 	ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 	       (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
 	ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
 	       (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);

 	if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
 				   BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
 		goto checksum_fail;

 	if (ipv6 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
 		goto checksum_fail;

 	/* check for L4 errors and handle packets that were not able to be
 	 * checksummed due to arrival speed
 	 */
 	if (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
 		goto checksum_fail;

 	/* check for outer UDP checksum error in tunneled packets */
 	if ((rx_status1 & BIT(ICE_RX_FLEX_DESC_STATUS1_NAT_S)) &&
 	    (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S)))
 		goto checksum_fail;

 	/* If there is an outer header present that might contain a checksum
 	 * we need to bump the checksum level by 1 to reflect the fact that
 	 * we are indicating we validated the inner checksum.
 	 */
 	if (decoded.tunnel_type >= ICE_RX_PTYPE_TUNNEL_IP_GRENAT)
 		skb->csum_level = 1;

 	/* Only report checksum unnecessary for TCP, UDP, or SCTP */
 	switch (decoded.inner_prot) {
 	case ICE_RX_PTYPE_INNER_PROT_TCP:
 	case ICE_RX_PTYPE_INNER_PROT_UDP:
 	case ICE_RX_PTYPE_INNER_PROT_SCTP:
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 		break;
 	default:
 		break;
 	}
 	return;

 checksum_fail:
 	ring->vsi->back->hw_csum_rx_error++;
 }

 /**
  * ice_process_skb_fields - Populate skb header fields from Rx descriptor
  * @rx_ring: Rx descriptor ring packet is being transacted on
  * @rx_desc: pointer to the EOP Rx descriptor
  * @skb: pointer to current skb being populated
  * @ptype: the packet type decoded by hardware
  *
  * This function checks the ring, descriptor, and packet information in
  * order to populate the hash, checksum, VLAN, protocol, and
  * other fields within the skb.
  */
 void
 ice_process_skb_fields(struct ice_ring *rx_ring,
 		       union ice_32b_rx_flex_desc *rx_desc,
 		       struct sk_buff *skb, u16 ptype)
 {
 	ice_rx_hash(rx_ring, rx_desc, skb, ptype);

 	/* modifies the skb - consumes the enet header */
 	skb->protocol = eth_type_trans(skb, rx_ring->netdev);

 	ice_rx_csum(rx_ring, skb, rx_desc, ptype);

 	if (rx_ring->ptp_rx)
 		ice_ptp_rx_hwtstamp(rx_ring, rx_desc, skb);
 }

 /**
  * ice_receive_skb - Send a completed packet up the stack
  * @rx_ring: Rx ring in play
  * @skb: packet to send up
  * @vlan_tag: VLAN tag for packet
  *
  * This function sends the completed packet (via. skb) up the stack using
  * gro receive functions (with/without VLAN tag)
  */
 void
 ice_receive_skb(struct ice_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
 {
 	if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
 	    (vlan_tag & VLAN_VID_MASK))
 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 	napi_gro_receive(&rx_ring->q_vector->napi, skb);
 }

 /**
  * ice_xmit_xdp_ring - submit single packet to XDP ring for transmission
  * @data: packet data pointer
  * @size: packet data size
  * @xdp_ring: XDP ring for transmission
  */
 int ice_xmit_xdp_ring(void *data, u16 size, struct ice_ring *xdp_ring)
 {
 	u16 i = xdp_ring->next_to_use;
 	struct ice_tx_desc *tx_desc;
 	struct ice_tx_buf *tx_buf;
 	dma_addr_t dma;

 	if (!unlikely(ICE_DESC_UNUSED(xdp_ring))) {
 		xdp_ring->tx_stats.tx_busy++;
 		return ICE_XDP_CONSUMED;
 	}

 	dma = dma_map_single(xdp_ring->dev, data, size, DMA_TO_DEVICE);
 	if (dma_mapping_error(xdp_ring->dev, dma))
 		return ICE_XDP_CONSUMED;

 	tx_buf = &xdp_ring->tx_buf[i];
 	tx_buf->bytecount = size;
 	tx_buf->gso_segs = 1;
 	tx_buf->raw_buf = data;

 	/* record length, and DMA address */
 	dma_unmap_len_set(tx_buf, len, size);
 	dma_unmap_addr_set(tx_buf, dma, dma);

 	tx_desc = ICE_TX_DESC(xdp_ring, i);
 	tx_desc->buf_addr = cpu_to_le64(dma);
 	tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TXD_LAST_DESC_CMD, 0,
 						      size, 0);

 	/* Make certain all of the status bits have been updated
 	 * before next_to_watch is written.
 	 */
 	smp_wmb();

 	i++;
 	if (i == xdp_ring->count)
 		i = 0;

 	tx_buf->next_to_watch = tx_desc;
 	xdp_ring->next_to_use = i;

 	return ICE_XDP_TX;
 }

 /**
  * ice_xmit_xdp_buff - convert an XDP buffer to an XDP frame and send it
  * @xdp: XDP buffer
  * @xdp_ring: XDP Tx ring
  *
  * Returns negative on failure, 0 on success.
  */
 int ice_xmit_xdp_buff(struct xdp_buff *xdp, struct ice_ring *xdp_ring)
 {
 	struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);

 	if (unlikely(!xdpf))
 		return ICE_XDP_CONSUMED;

 	return ice_xmit_xdp_ring(xdpf->data, xdpf->len, xdp_ring);
 }

 /**
  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
  * @rx_ring: Rx ring
  * @xdp_res: Result of the receive batch
  *
  * This function bumps XDP Tx tail and/or flush redirect map, and
  * should be called when a batch of packets has been processed in the
  * napi loop.
  */
 void ice_finalize_xdp_rx(struct ice_ring *rx_ring, unsigned int xdp_res)
 {
 	if (xdp_res & ICE_XDP_REDIR)
 		xdp_do_flush_map();

 	if (xdp_res & ICE_XDP_TX) {
 		struct ice_ring *xdp_ring =
 			rx_ring->vsi->xdp_rings[rx_ring->q_index];

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

	#include "ice_txrx_lib.h"

	/**
	* ice_release_rx_desc - Store the new tail and head values
	* @rx_ring: ring to bump
	* @val: new head index
	*/
	void ice_release_rx_desc(struct ice_ring *rx_ring, u16 val)
	{
	u16 prev_ntu = rx_ring->next_to_use & ~0x7;

	rx_ring->next_to_use = val;

	/* update next to alloc since we have filled the ring */
	rx_ring->next_to_alloc = val;

	/* QRX_TAIL will be updated with any tail value, but hardware ignores
	* the lower 3 bits. This makes it so we only bump tail on meaningful
	* boundaries. Also, this allows us to bump tail on intervals of 8 up to
	* the budget depending on the current traffic load.
	*/
	val &= ~0x7;
	if (prev_ntu != val) {
	/* Force memory writes to complete before letting h/w
	* know there are new descriptors to fetch. (Only
	* applicable for weak-ordered memory model archs,
	* such as IA-64).
	*/
	wmb();
	writel(val, rx_ring->tail);
	}
	}

	/**
	* ice_ptype_to_htype - get a hash type
	* @ptype: the ptype value from the descriptor
	*
	* Returns appropriate hash type (such as PKT_HASH_TYPE_L2/L3/L4) to be used by
	* skb_set_hash based on PTYPE as parsed by HW Rx pipeline and is part of
	* Rx desc.
	*/
	static enum pkt_hash_types ice_ptype_to_htype(u16 ptype)
	{
	struct ice_rx_ptype_decoded decoded = ice_decode_rx_desc_ptype(ptype);

	if (!decoded.known)
	return PKT_HASH_TYPE_NONE;
	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY4)
	return PKT_HASH_TYPE_L4;
	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY3)
	return PKT_HASH_TYPE_L3;
	if (decoded.outer_ip == ICE_RX_PTYPE_OUTER_L2)
	return PKT_HASH_TYPE_L2;

	return PKT_HASH_TYPE_NONE;
	}

	/**
	* ice_rx_hash - set the hash value in the skb
	* @rx_ring: descriptor ring
	* @rx_desc: specific descriptor
	* @skb: pointer to current skb
	* @rx_ptype: the ptype value from the descriptor
	*/
	static void
	ice_rx_hash(struct ice_ring rx_ring, union ice_32b_rx_flex_desc rx_desc,
	struct sk_buff *skb, u16 rx_ptype)
	{
	struct ice_32b_rx_flex_desc_nic *nic_mdid;
	u32 hash;

	if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
	return;

	if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
	return;

	nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
	hash = le32_to_cpu(nic_mdid->rss_hash);
	skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
	}

	/**
	* ice_rx_csum - Indicate in skb if checksum is good
	* @ring: the ring we care about
	* @skb: skb currently being received and modified
	* @rx_desc: the receive descriptor
	* @ptype: the packet type decoded by hardware
	*
	* skb->protocol must be set before this function is called
	*/
	static void
	ice_rx_csum(struct ice_ring ring, struct sk_buff skb,
	union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
	{
	struct ice_rx_ptype_decoded decoded;
	u16 rx_status0, rx_status1;
	bool ipv4, ipv6;

	rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
	rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);

	decoded = ice_decode_rx_desc_ptype(ptype);

	/* Start with CHECKSUM_NONE and by default csum_level = 0 */
	skb->ip_summed = CHECKSUM_NONE;
	skb_checksum_none_assert(skb);

	/* check if Rx checksum is enabled */
	if (!(ring->netdev->features & NETIF_F_RXCSUM))
	return;

	/* check if HW has decoded the packet and checksum */
	if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
	return;

	if (!(decoded.known && decoded.outer_ip))
	return;

	ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
	(decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
	ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
	(decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);

	if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) \|
	BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
	goto checksum_fail;

	if (ipv6 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
	goto checksum_fail;

	/* check for L4 errors and handle packets that were not able to be
	* checksummed due to arrival speed
	*/
	if (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
	goto checksum_fail;

	/* check for outer UDP checksum error in tunneled packets */
	if ((rx_status1 & BIT(ICE_RX_FLEX_DESC_STATUS1_NAT_S)) &&
	(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S)))
	goto checksum_fail;

	/* If there is an outer header present that might contain a checksum
	* we need to bump the checksum level by 1 to reflect the fact that
	* we are indicating we validated the inner checksum.
	*/
	if (decoded.tunnel_type >= ICE_RX_PTYPE_TUNNEL_IP_GRENAT)
	skb->csum_level = 1;

	/* Only report checksum unnecessary for TCP, UDP, or SCTP */
	switch (decoded.inner_prot) {
	case ICE_RX_PTYPE_INNER_PROT_TCP:
	case ICE_RX_PTYPE_INNER_PROT_UDP:
	case ICE_RX_PTYPE_INNER_PROT_SCTP:
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	break;
	default:
	break;
	}
	return;

	checksum_fail:
	ring->vsi->back->hw_csum_rx_error++;
	}

	/**
	* ice_process_skb_fields - Populate skb header fields from Rx descriptor
	* @rx_ring: Rx descriptor ring packet is being transacted on
	* @rx_desc: pointer to the EOP Rx descriptor
	* @skb: pointer to current skb being populated
	* @ptype: the packet type decoded by hardware
	*
	* This function checks the ring, descriptor, and packet information in
	* order to populate the hash, checksum, VLAN, protocol, and
	* other fields within the skb.
	*/
	void
	ice_process_skb_fields(struct ice_ring *rx_ring,
	union ice_32b_rx_flex_desc *rx_desc,
	struct sk_buff *skb, u16 ptype)
	{
	ice_rx_hash(rx_ring, rx_desc, skb, ptype);

	/* modifies the skb - consumes the enet header */
	skb->protocol = eth_type_trans(skb, rx_ring->netdev);

	ice_rx_csum(rx_ring, skb, rx_desc, ptype);

	if (rx_ring->ptp_rx)
	ice_ptp_rx_hwtstamp(rx_ring, rx_desc, skb);
	}

	/**
	* ice_receive_skb - Send a completed packet up the stack
	* @rx_ring: Rx ring in play
	* @skb: packet to send up
	* @vlan_tag: VLAN tag for packet
	*
	* This function sends the completed packet (via. skb) up the stack using
	* gro receive functions (with/without VLAN tag)
	*/
	void
	ice_receive_skb(struct ice_ring rx_ring, struct sk_buff skb, u16 vlan_tag)
	{
	if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
	(vlan_tag & VLAN_VID_MASK))
	__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
	napi_gro_receive(&rx_ring->q_vector->napi, skb);
	}

	/**
	* ice_xmit_xdp_ring - submit single packet to XDP ring for transmission
	* @data: packet data pointer
	* @size: packet data size
	* @xdp_ring: XDP ring for transmission
	*/
	int ice_xmit_xdp_ring(void data, u16 size, struct ice_ring xdp_ring)
	{
	u16 i = xdp_ring->next_to_use;
	struct ice_tx_desc *tx_desc;
	struct ice_tx_buf *tx_buf;
	dma_addr_t dma;

	if (!unlikely(ICE_DESC_UNUSED(xdp_ring))) {
	xdp_ring->tx_stats.tx_busy++;
	return ICE_XDP_CONSUMED;
	}

	dma = dma_map_single(xdp_ring->dev, data, size, DMA_TO_DEVICE);
	if (dma_mapping_error(xdp_ring->dev, dma))
	return ICE_XDP_CONSUMED;

	tx_buf = &xdp_ring->tx_buf[i];
	tx_buf->bytecount = size;
	tx_buf->gso_segs = 1;
	tx_buf->raw_buf = data;

	/* record length, and DMA address */
	dma_unmap_len_set(tx_buf, len, size);
	dma_unmap_addr_set(tx_buf, dma, dma);

	tx_desc = ICE_TX_DESC(xdp_ring, i);
	tx_desc->buf_addr = cpu_to_le64(dma);
	tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TXD_LAST_DESC_CMD, 0,
	size, 0);

	/* Make certain all of the status bits have been updated
	* before next_to_watch is written.
	*/
	smp_wmb();

	i++;
	if (i == xdp_ring->count)
	i = 0;

	tx_buf->next_to_watch = tx_desc;
	xdp_ring->next_to_use = i;

	return ICE_XDP_TX;
	}

	/**
	* ice_xmit_xdp_buff - convert an XDP buffer to an XDP frame and send it
	* @xdp: XDP buffer
	* @xdp_ring: XDP Tx ring
	*
	* Returns negative on failure, 0 on success.
	*/
	int ice_xmit_xdp_buff(struct xdp_buff xdp, struct ice_ring xdp_ring)
	{
	struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);

	if (unlikely(!xdpf))
	return ICE_XDP_CONSUMED;

	return ice_xmit_xdp_ring(xdpf->data, xdpf->len, xdp_ring);
	}

	/**
	* ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
	* @rx_ring: Rx ring
	* @xdp_res: Result of the receive batch
	*
	* This function bumps XDP Tx tail and/or flush redirect map, and
	* should be called when a batch of packets has been processed in the
	* napi loop.
	*/
	void ice_finalize_xdp_rx(struct ice_ring *rx_ring, unsigned int xdp_res)
	{
	if (xdp_res & ICE_XDP_REDIR)
	xdp_do_flush_map();

	if (xdp_res & ICE_XDP_TX) {
	struct ice_ring *xdp_ring =
	rx_ring->vsi->xdp_rings[rx_ring->q_index];

	ice_xdp_ring_update_tail(xdp_ring);
	}
	}