include/net/xsk_buff_pool.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* Copyright(c) 2020 Intel Corporation. */
   3
   4 #ifndef XSK_BUFF_POOL_H_
   5 #define XSK_BUFF_POOL_H_
   6
   7 #include <linux/if_xdp.h>
   8 #include <linux/types.h>
   9 #include <linux/dma-mapping.h>
  10 #include <linux/bpf.h>
  11 #include <net/xdp.h>
  12
  13 struct xsk_buff_pool;
  14 struct xdp_rxq_info;
  15 struct xsk_cb_desc;
  16 struct xsk_queue;
  17 struct xdp_desc;
  18 struct xdp_umem;
  19 struct xdp_sock;
  20 struct device;
  21 struct page;
  22
  23 #define XSK_PRIV_MAX 24
  24
  25 struct xdp_buff_xsk {
  26         struct xdp_buff xdp;
  27         u8 cb[XSK_PRIV_MAX];
  28         dma_addr_t dma;
  29         dma_addr_t frame_dma;
  30         struct xsk_buff_pool *pool;
  31         struct list_head list_node;
  32 };
  33
  34 #define XSK_CHECK_PRIV_TYPE(t) BUILD_BUG_ON(sizeof(t) > offsetofend(struct xdp_buff_xsk, cb))
  35 #define XSK_TX_COMPL_FITS(t) BUILD_BUG_ON(sizeof(struct xsk_tx_metadata_compl) > sizeof(t))
  36
  37 struct xsk_dma_map {
  38         dma_addr_t *dma_pages;
  39         struct device *dev;
  40         struct net_device *netdev;
  41         refcount_t users;
  42         struct list_head list; /* Protected by the RTNL_LOCK */
  43         u32 dma_pages_cnt;
  44 };
  45
  46 struct xsk_buff_pool {
  47         /* Members only used in the control path first. */
  48         struct device *dev;
  49         struct net_device *netdev;
  50         struct list_head xsk_tx_list;
  51         /* Protects modifications to the xsk_tx_list */
  52         spinlock_t xsk_tx_list_lock;
  53         refcount_t users;
  54         struct xdp_umem *umem;
  55         struct work_struct work;
  56         struct list_head free_list;
  57         struct list_head xskb_list;
  58         u32 heads_cnt;
  59         u16 queue_id;
  60
  61         /* Data path members as close to free_heads at the end as possible. */
  62         struct xsk_queue *fq ____cacheline_aligned_in_smp;
  63         struct xsk_queue *cq;
  64         /* For performance reasons, each buff pool has its own array of dma_pages
  65          * even when they are identical.
  66          */
  67         dma_addr_t *dma_pages;
  68         struct xdp_buff_xsk *heads;
  69         struct xdp_desc *tx_descs;
  70         u64 chunk_mask;
  71         u64 addrs_cnt;
  72         u32 free_list_cnt;
  73         u32 dma_pages_cnt;
  74         u32 free_heads_cnt;
  75         u32 headroom;
  76         u32 chunk_size;
  77         u32 chunk_shift;
  78         u32 frame_len;
  79         u32 xdp_zc_max_segs;
  80         u8 tx_metadata_len; /* inherited from umem */
  81         u8 cached_need_wakeup;
  82         bool uses_need_wakeup;
  83         bool unaligned;
  84         bool tx_sw_csum;
  85         void *addrs;
  86         /* Mutual exclusion of the completion ring in the SKB mode. Two cases to protect:
  87          * NAPI TX thread and sendmsg error paths in the SKB destructor callback and when
  88          * sockets share a single cq when the same netdev and queue id is shared.
  89          */
  90         spinlock_t cq_lock;
  91         struct xdp_buff_xsk *free_heads[];
  92 };
  93
  94 /* Masks for xdp_umem_page flags.
  95  * The low 12-bits of the addr will be 0 since this is the page address, so we
  96  * can use them for flags.
  97  */
  98 #define XSK_NEXT_PG_CONTIG_SHIFT 0
  99 #define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
 100
 101 /* AF_XDP core. */
 102 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 103                                                 struct xdp_umem *umem);
 104 int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
 105                   u16 queue_id, u16 flags);
 106 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
 107                          struct net_device *dev, u16 queue_id);
 108 int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs);
 109 void xp_destroy(struct xsk_buff_pool *pool);
 110 void xp_get_pool(struct xsk_buff_pool *pool);
 111 bool xp_put_pool(struct xsk_buff_pool *pool);
 112 void xp_clear_dev(struct xsk_buff_pool *pool);
 113 void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
 114 void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
 115
 116 /* AF_XDP, and XDP core. */
 117 void xp_free(struct xdp_buff_xsk *xskb);
 118
 119 static inline void xp_init_xskb_addr(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
 120                                      u64 addr)
 121 {
 122         xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
 123 }
 124
 125 static inline void xp_init_xskb_dma(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
 126                                     dma_addr_t *dma_pages, u64 addr)
 127 {
 128         xskb->frame_dma = (dma_pages[addr >> PAGE_SHIFT] & ~XSK_NEXT_PG_CONTIG_MASK) +
 129                 (addr & ~PAGE_MASK);
 130         xskb->dma = xskb->frame_dma + pool->headroom + XDP_PACKET_HEADROOM;
 131 }
 132
 133 /* AF_XDP ZC drivers, via xdp_sock_buff.h */
 134 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq);
 135 void xp_fill_cb(struct xsk_buff_pool *pool, struct xsk_cb_desc *desc);
 136 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
 137                unsigned long attrs, struct page **pages, u32 nr_pages);
 138 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs);
 139 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool);
 140 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max);
 141 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count);
 142 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr);
 143 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr);
 144 static inline dma_addr_t xp_get_dma(struct xdp_buff_xsk *xskb)
 145 {
 146         return xskb->dma;
 147 }
 148
 149 static inline dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb)
 150 {
 151         return xskb->frame_dma;
 152 }
 153
 154 static inline void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb)
 155 {
 156         dma_sync_single_for_cpu(xskb->pool->dev, xskb->dma,
 157                                 xskb->pool->frame_len,
 158                                 DMA_BIDIRECTIONAL);
 159 }
 160
 161 static inline void xp_dma_sync_for_device(struct xsk_buff_pool *pool,
 162                                           dma_addr_t dma, size_t size)
 163 {
 164         dma_sync_single_for_device(pool->dev, dma, size, DMA_BIDIRECTIONAL);
 165 }
 166
 167 /* Masks for xdp_umem_page flags.
 168  * The low 12-bits of the addr will be 0 since this is the page address, so we
 169  * can use them for flags.
 170  */
 171 #define XSK_NEXT_PG_CONTIG_SHIFT 0
 172 #define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
 173
 174 static inline bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool,
 175                                                  u64 addr, u32 len)
 176 {
 177         bool cross_pg = (addr & (PAGE_SIZE - 1)) + len > PAGE_SIZE;
 178
 179         if (likely(!cross_pg))
 180                 return false;
 181
 182         return pool->dma_pages &&
 183                !(pool->dma_pages[addr >> PAGE_SHIFT] & XSK_NEXT_PG_CONTIG_MASK);
 184 }
 185
 186 static inline bool xp_mb_desc(struct xdp_desc *desc)
 187 {
 188         return desc->options & XDP_PKT_CONTD;
 189 }
 190
 191 static inline u64 xp_aligned_extract_addr(struct xsk_buff_pool *pool, u64 addr)
 192 {
 193         return addr & pool->chunk_mask;
 194 }
 195
 196 static inline u64 xp_unaligned_extract_addr(u64 addr)
 197 {
 198         return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
 199 }
 200
 201 static inline u64 xp_unaligned_extract_offset(u64 addr)
 202 {
 203         return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
 204 }
 205
 206 static inline u64 xp_unaligned_add_offset_to_addr(u64 addr)
 207 {
 208         return xp_unaligned_extract_addr(addr) +
 209                 xp_unaligned_extract_offset(addr);
 210 }
 211
 212 static inline u32 xp_aligned_extract_idx(struct xsk_buff_pool *pool, u64 addr)
 213 {
 214         return xp_aligned_extract_addr(pool, addr) >> pool->chunk_shift;
 215 }
 216
 217 static inline void xp_release(struct xdp_buff_xsk *xskb)
 218 {
 219         if (xskb->pool->unaligned)
 220                 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
 221 }
 222
 223 static inline u64 xp_get_handle(struct xdp_buff_xsk *xskb,
 224                                 struct xsk_buff_pool *pool)
 225 {
 226         u64 orig_addr = xskb->xdp.data - pool->addrs;
 227         u64 offset;
 228
 229         if (!pool->unaligned)
 230                 return orig_addr;
 231
 232         offset = xskb->xdp.data - xskb->xdp.data_hard_start;
 233         orig_addr -= offset;
 234         offset += pool->headroom;
 235         return orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
 236 }
 237
 238 static inline bool xp_tx_metadata_enabled(const struct xsk_buff_pool *pool)
 239 {
 240         return pool->tx_metadata_len > 0;
 241 }
 242
 243 #endif /* XSK_BUFF_POOL_H_ */