nfp/nfdk/nfdk.h

0001 /* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
0002 /* Copyright (C) 2019 Netronome Systems, Inc. */
0003
0004 #ifndef _NFP_DP_NFDK_H_
0005 #define _NFP_DP_NFDK_H_
0006
0007 #include <linux/bitops.h>
0008 #include <linux/types.h>
0009
0010 #define NFDK_TX_DESC_PER_SIMPLE_PKT 2
0011
0012 #define NFDK_TX_MAX_DATA_PER_HEAD   SZ_4K
0013 #define NFDK_TX_MAX_DATA_PER_DESC   SZ_16K
0014 #define NFDK_TX_DESC_BLOCK_SZ       256
0015 #define NFDK_TX_DESC_BLOCK_CNT      (NFDK_TX_DESC_BLOCK_SZ /    \
0016                      sizeof(struct nfp_nfdk_tx_desc))
0017 #define NFDK_TX_DESC_STOP_CNT       (NFDK_TX_DESC_BLOCK_CNT *   \
0018                      NFDK_TX_DESC_PER_SIMPLE_PKT)
0019 #define NFDK_TX_MAX_DATA_PER_BLOCK  SZ_64K
0020 #define NFDK_TX_DESC_GATHER_MAX     17
0021
0022 /* TX descriptor format */
0023
0024 #define NFDK_DESC_TX_MSS_MASK       GENMASK(13, 0)
0025
0026 #define NFDK_DESC_TX_CHAIN_META     BIT(3)
0027 #define NFDK_DESC_TX_ENCAP      BIT(2)
0028 #define NFDK_DESC_TX_L4_CSUM        BIT(1)
0029 #define NFDK_DESC_TX_L3_CSUM        BIT(0)
0030
0031 #define NFDK_DESC_TX_DMA_LEN_HEAD   GENMASK(11, 0)
0032 #define NFDK_DESC_TX_TYPE_HEAD      GENMASK(15, 12)
0033 #define NFDK_DESC_TX_DMA_LEN        GENMASK(13, 0)
0034 #define NFDK_DESC_TX_TYPE_NOP       0
0035 #define NFDK_DESC_TX_TYPE_GATHER    1
0036 #define NFDK_DESC_TX_TYPE_TSO       2
0037 #define NFDK_DESC_TX_TYPE_SIMPLE    8
0038 #define NFDK_DESC_TX_EOP        BIT(14)
0039
0040 #define NFDK_META_LEN           GENMASK(7, 0)
0041 #define NFDK_META_FIELDS        GENMASK(31, 8)
0042
0043 #define D_BLOCK_CPL(idx)        (NFDK_TX_DESC_BLOCK_CNT -   \
0044                      (idx) % NFDK_TX_DESC_BLOCK_CNT)
0045
0046 struct nfp_nfdk_tx_desc {
0047     union {
0048         struct {
0049             __le16 dma_addr_hi;  /* High bits of host buf address */
0050             __le16 dma_len_type; /* Length to DMA for this desc */
0051             __le32 dma_addr_lo;  /* Low 32bit of host buf addr */
0052         };
0053
0054         struct {
0055             __le16 mss; /* MSS to be used for LSO */
0056             u8 lso_hdrlen;  /* LSO, TCP payload offset */
0057             u8 lso_totsegs; /* LSO, total segments */
0058             u8 l3_offset;   /* L3 header offset */
0059             u8 l4_offset;   /* L4 header offset */
0060             __le16 lso_meta_res; /* Rsvd bits in TSO metadata */
0061         };
0062
0063         struct {
0064             u8 flags;   /* TX Flags, see @NFDK_DESC_TX_* */
0065             u8 reserved[7]; /* meta byte placeholder */
0066         };
0067
0068         __le32 vals[2];
0069         __le64 raw;
0070     };
0071 };
0072
0073 /* The device don't make use of the 2 or 3 least significant bits of the address
0074  * due to alignment constraints. The driver can make use of those bits to carry
0075  * information about the buffer before giving it to the device.
0076  *
0077  * NOTE: The driver must clear the lower bits before handing the buffer to the
0078  * device.
0079  *
0080  * - NFDK_TX_BUF_INFO_SOP - Start of a packet
0081  *   Mark the buffer as a start of a packet. This is used in the XDP TX process
0082  *   to stash virtual and DMA address so that they can be recycled when the TX
0083  *   operation is completed.
0084  */
0085 #define NFDK_TX_BUF_PTR(val) ((val) & ~(sizeof(void *) - 1))
0086 #define NFDK_TX_BUF_INFO(val) ((val) & (sizeof(void *) - 1))
0087 #define NFDK_TX_BUF_INFO_SOP BIT(0)
0088
0089 struct nfp_nfdk_tx_buf {
0090     union {
0091         /* First slot */
0092         union {
0093             struct sk_buff *skb;
0094             void *frag;
0095             unsigned long val;
0096         };
0097
0098         /* 1 + nr_frags next slots */
0099         dma_addr_t dma_addr;
0100
0101         /* TSO (optional) */
0102         struct {
0103             u32 pkt_cnt;
0104             u32 real_len;
0105         };
0106
0107         u64 raw;
0108     };
0109 };
0110
0111 static inline int nfp_nfdk_headlen_to_segs(unsigned int headlen)
0112 {
0113     /* First descriptor fits less data, so adjust for that */
0114     return DIV_ROUND_UP(headlen +
0115                 NFDK_TX_MAX_DATA_PER_DESC -
0116                 NFDK_TX_MAX_DATA_PER_HEAD,
0117                 NFDK_TX_MAX_DATA_PER_DESC);
0118 }
0119
0120 int nfp_nfdk_poll(struct napi_struct *napi, int budget);
0121 netdev_tx_t nfp_nfdk_tx(struct sk_buff *skb, struct net_device *netdev);
0122 bool
0123 nfp_nfdk_ctrl_tx_one(struct nfp_net *nn, struct nfp_net_r_vector *r_vec,
0124              struct sk_buff *skb, bool old);
0125 void nfp_nfdk_ctrl_poll(struct tasklet_struct *t);
0126 void nfp_nfdk_rx_ring_fill_freelist(struct nfp_net_dp *dp,
0127                     struct nfp_net_rx_ring *rx_ring);
0128 #endif