// 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 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;
        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, 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 = 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);
        }
}