/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
/* Copyright (C) 2019 Netronome Systems, Inc. */

#ifndef _NFP_DP_NFDK_H_
#define _NFP_DP_NFDK_H_

#include <linux/bitops.h>
#include <linux/types.h>

#define NFDK_TX_DESC_PER_SIMPLE_PKT     2

#define NFDK_TX_MAX_DATA_PER_HEAD       SZ_4K
#define NFDK_TX_MAX_DATA_PER_DESC       SZ_16K
#define NFDK_TX_DESC_BLOCK_SZ           256
#define NFDK_TX_DESC_BLOCK_CNT          (NFDK_TX_DESC_BLOCK_SZ /        \
                                         sizeof(struct nfp_nfdk_tx_desc))
#define NFDK_TX_DESC_STOP_CNT           (NFDK_TX_DESC_BLOCK_CNT *       \
                                         NFDK_TX_DESC_PER_SIMPLE_PKT)
#define NFDK_TX_MAX_DATA_PER_BLOCK      SZ_64K
#define NFDK_TX_DESC_GATHER_MAX         17

/* TX descriptor format */

#define NFDK_DESC_TX_MSS_MASK           GENMASK(13, 0)

#define NFDK_DESC_TX_CHAIN_META         BIT(3)
#define NFDK_DESC_TX_ENCAP              BIT(2)
#define NFDK_DESC_TX_L4_CSUM            BIT(1)
#define NFDK_DESC_TX_L3_CSUM            BIT(0)

#define NFDK_DESC_TX_DMA_LEN_HEAD       GENMASK(11, 0)
#define NFDK_DESC_TX_TYPE_HEAD          GENMASK(15, 12)
#define NFDK_DESC_TX_DMA_LEN            GENMASK(13, 0)
#define NFDK_DESC_TX_TYPE_NOP           0
#define NFDK_DESC_TX_TYPE_GATHER        1
#define NFDK_DESC_TX_TYPE_TSO           2
#define NFDK_DESC_TX_TYPE_SIMPLE        8
#define NFDK_DESC_TX_EOP                BIT(14)

#define NFDK_META_LEN                   GENMASK(7, 0)
#define NFDK_META_FIELDS                GENMASK(31, 8)

#define D_BLOCK_CPL(idx)                (NFDK_TX_DESC_BLOCK_CNT -       \
                                         (idx) % NFDK_TX_DESC_BLOCK_CNT)

struct nfp_nfdk_tx_desc {
        union {
                struct {
                        __le16 dma_addr_hi;  /* High bits of host buf address */
                        __le16 dma_len_type; /* Length to DMA for this desc */
                        __le32 dma_addr_lo;  /* Low 32bit of host buf addr */
                };

                struct {
                        __le16 mss;     /* MSS to be used for LSO */
                        u8 lso_hdrlen;  /* LSO, TCP payload offset */
                        u8 lso_totsegs; /* LSO, total segments */
                        u8 l3_offset;   /* L3 header offset */
                        u8 l4_offset;   /* L4 header offset */
                        __le16 lso_meta_res; /* Rsvd bits in TSO metadata */
                };

                struct {
                        u8 flags;       /* TX Flags, see @NFDK_DESC_TX_* */
                        u8 reserved[7]; /* meta byte placeholder */
                };

                __le32 vals[2];
                __le64 raw;
        };
};

/* The device don't make use of the 2 or 3 least significant bits of the address
 * due to alignment constraints. The driver can make use of those bits to carry
 * information about the buffer before giving it to the device.
 *
 * NOTE: The driver must clear the lower bits before handing the buffer to the
 * device.
 *
 * - NFDK_TX_BUF_INFO_SOP - Start of a packet
 *   Mark the buffer as a start of a packet. This is used in the XDP TX process
 *   to stash virtual and DMA address so that they can be recycled when the TX
 *   operation is completed.
 */
#define NFDK_TX_BUF_PTR(val) ((val) & ~(sizeof(void *) - 1))
#define NFDK_TX_BUF_INFO(val) ((val) & (sizeof(void *) - 1))
#define NFDK_TX_BUF_INFO_SOP BIT(0)

struct nfp_nfdk_tx_buf {
        union {
                /* First slot */
                union {
                        struct sk_buff *skb;
                        void *frag;
                        unsigned long val;
                };

                /* 1 + nr_frags next slots */
                dma_addr_t dma_addr;

                /* TSO (optional) */
                struct {
                        u32 pkt_cnt;
                        u32 real_len;
                };

                u64 raw;
        };
};

static inline int nfp_nfdk_headlen_to_segs(unsigned int headlen)
{
        /* First descriptor fits less data, so adjust for that */
        return DIV_ROUND_UP(headlen +
                            NFDK_TX_MAX_DATA_PER_DESC -
                            NFDK_TX_MAX_DATA_PER_HEAD,
                            NFDK_TX_MAX_DATA_PER_DESC);
}

int nfp_nfdk_poll(struct napi_struct *napi, int budget);
netdev_tx_t nfp_nfdk_tx(struct sk_buff *skb, struct net_device *netdev);
bool
nfp_nfdk_ctrl_tx_one(struct nfp_net *nn, struct nfp_net_r_vector *r_vec,
                     struct sk_buff *skb, bool old);
void nfp_nfdk_ctrl_poll(struct tasklet_struct *t);
void nfp_nfdk_rx_ring_fill_freelist(struct nfp_net_dp *dp,
                                    struct nfp_net_rx_ring *rx_ring);
#ifndef CONFIG_NFP_NET_IPSEC
static inline u64 nfp_nfdk_ipsec_tx(u64 flags, struct sk_buff *skb)
{
        return flags;
}
#else
u64 nfp_nfdk_ipsec_tx(u64 flags, struct sk_buff *skb);
#endif
#endif