ice: Move common functions to ice_txrx_lib.c

In preparation of AF XDP, move functions that will be used both by skb and
zero-copy paths to a new file called ice_txrx_lib.c.  This allows us to
avoid using ifdefs to control the staticness of said functions.

Move other functions (ice_rx_csum, ice_rx_hash and ice_ptype_to_htype)
called only by the moved ones to the new file as well.

Signed-off-by: Krzysztof Kazimierczak <krzysztof.kazimierczak@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 273 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
new file mode 100644
index 000000000000..35bbc4ff603c
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
@@ -0,0 +1,273 @@
+// 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, u32 val)
+{
+	u16 prev_ntu = rx_ring->next_to_use;
+
+	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 a hash type to be used by skb_set_hash
+ */
+static enum pkt_hash_types ice_ptype_to_htype(u8 __always_unused ptype)
+{
+	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, u8 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, u8 ptype)
+{
+	struct ice_rx_ptype_decoded decoded;
+	u32 rx_error, rx_status;
+	bool ipv4, ipv6;
+
+	rx_status = le16_to_cpu(rx_desc->wb.status_error0);
+	rx_error = rx_status;
+
+	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_status & 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_error & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
+				 BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
+		goto checksum_fail;
+	else if (ipv6 && (rx_status &
+		 (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_error & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
+		goto checksum_fail;
+
+	/* 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;
+	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, u8 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);
+}
+
+/**
+ * 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 = 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 = convert_to_xdp_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);
+	}
+}