xsk_buff_pool.h (6610B)
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 13struct xsk_buff_pool; 14struct xdp_rxq_info; 15struct xsk_queue; 16struct xdp_desc; 17struct xdp_umem; 18struct xdp_sock; 19struct device; 20struct page; 21 22struct xdp_buff_xsk { 23 struct xdp_buff xdp; 24 dma_addr_t dma; 25 dma_addr_t frame_dma; 26 struct xsk_buff_pool *pool; 27 u64 orig_addr; 28 struct list_head free_list_node; 29}; 30 31struct xsk_dma_map { 32 dma_addr_t *dma_pages; 33 struct device *dev; 34 struct net_device *netdev; 35 refcount_t users; 36 struct list_head list; /* Protected by the RTNL_LOCK */ 37 u32 dma_pages_cnt; 38 bool dma_need_sync; 39}; 40 41struct xsk_buff_pool { 42 /* Members only used in the control path first. */ 43 struct device *dev; 44 struct net_device *netdev; 45 struct list_head xsk_tx_list; 46 /* Protects modifications to the xsk_tx_list */ 47 spinlock_t xsk_tx_list_lock; 48 refcount_t users; 49 struct xdp_umem *umem; 50 struct work_struct work; 51 struct list_head free_list; 52 u32 heads_cnt; 53 u16 queue_id; 54 55 /* Data path members as close to free_heads at the end as possible. */ 56 struct xsk_queue *fq ____cacheline_aligned_in_smp; 57 struct xsk_queue *cq; 58 /* For performance reasons, each buff pool has its own array of dma_pages 59 * even when they are identical. 60 */ 61 dma_addr_t *dma_pages; 62 struct xdp_buff_xsk *heads; 63 struct xdp_desc *tx_descs; 64 u64 chunk_mask; 65 u64 addrs_cnt; 66 u32 free_list_cnt; 67 u32 dma_pages_cnt; 68 u32 free_heads_cnt; 69 u32 headroom; 70 u32 chunk_size; 71 u32 chunk_shift; 72 u32 frame_len; 73 u8 cached_need_wakeup; 74 bool uses_need_wakeup; 75 bool dma_need_sync; 76 bool unaligned; 77 void *addrs; 78 /* Mutual exclusion of the completion ring in the SKB mode. Two cases to protect: 79 * NAPI TX thread and sendmsg error paths in the SKB destructor callback and when 80 * sockets share a single cq when the same netdev and queue id is shared. 81 */ 82 spinlock_t cq_lock; 83 struct xdp_buff_xsk *free_heads[]; 84}; 85 86/* Masks for xdp_umem_page flags. 87 * The low 12-bits of the addr will be 0 since this is the page address, so we 88 * can use them for flags. 89 */ 90#define XSK_NEXT_PG_CONTIG_SHIFT 0 91#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT) 92 93/* AF_XDP core. */ 94struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, 95 struct xdp_umem *umem); 96int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev, 97 u16 queue_id, u16 flags); 98int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, 99 struct net_device *dev, u16 queue_id); 100int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs); 101void xp_destroy(struct xsk_buff_pool *pool); 102void xp_get_pool(struct xsk_buff_pool *pool); 103bool xp_put_pool(struct xsk_buff_pool *pool); 104void xp_clear_dev(struct xsk_buff_pool *pool); 105void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs); 106void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs); 107 108/* AF_XDP, and XDP core. */ 109void xp_free(struct xdp_buff_xsk *xskb); 110 111static inline void xp_init_xskb_addr(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool, 112 u64 addr) 113{ 114 xskb->orig_addr = addr; 115 xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom; 116} 117 118static inline void xp_init_xskb_dma(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool, 119 dma_addr_t *dma_pages, u64 addr) 120{ 121 xskb->frame_dma = (dma_pages[addr >> PAGE_SHIFT] & ~XSK_NEXT_PG_CONTIG_MASK) + 122 (addr & ~PAGE_MASK); 123 xskb->dma = xskb->frame_dma + pool->headroom + XDP_PACKET_HEADROOM; 124} 125 126/* AF_XDP ZC drivers, via xdp_sock_buff.h */ 127void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq); 128int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, 129 unsigned long attrs, struct page **pages, u32 nr_pages); 130void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs); 131struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool); 132u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max); 133bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count); 134void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr); 135dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr); 136static inline dma_addr_t xp_get_dma(struct xdp_buff_xsk *xskb) 137{ 138 return xskb->dma; 139} 140 141static inline dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb) 142{ 143 return xskb->frame_dma; 144} 145 146void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb); 147static inline void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb) 148{ 149 xp_dma_sync_for_cpu_slow(xskb); 150} 151 152void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma, 153 size_t size); 154static inline void xp_dma_sync_for_device(struct xsk_buff_pool *pool, 155 dma_addr_t dma, size_t size) 156{ 157 if (!pool->dma_need_sync) 158 return; 159 160 xp_dma_sync_for_device_slow(pool, dma, size); 161} 162 163/* Masks for xdp_umem_page flags. 164 * The low 12-bits of the addr will be 0 since this is the page address, so we 165 * can use them for flags. 166 */ 167#define XSK_NEXT_PG_CONTIG_SHIFT 0 168#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT) 169 170static inline bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool, 171 u64 addr, u32 len) 172{ 173 bool cross_pg = (addr & (PAGE_SIZE - 1)) + len > PAGE_SIZE; 174 175 if (likely(!cross_pg)) 176 return false; 177 178 if (pool->dma_pages_cnt) { 179 return !(pool->dma_pages[addr >> PAGE_SHIFT] & 180 XSK_NEXT_PG_CONTIG_MASK); 181 } 182 183 /* skb path */ 184 return addr + len > pool->addrs_cnt; 185} 186 187static inline u64 xp_aligned_extract_addr(struct xsk_buff_pool *pool, u64 addr) 188{ 189 return addr & pool->chunk_mask; 190} 191 192static inline u64 xp_unaligned_extract_addr(u64 addr) 193{ 194 return addr & XSK_UNALIGNED_BUF_ADDR_MASK; 195} 196 197static inline u64 xp_unaligned_extract_offset(u64 addr) 198{ 199 return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT; 200} 201 202static inline u64 xp_unaligned_add_offset_to_addr(u64 addr) 203{ 204 return xp_unaligned_extract_addr(addr) + 205 xp_unaligned_extract_offset(addr); 206} 207 208static inline u32 xp_aligned_extract_idx(struct xsk_buff_pool *pool, u64 addr) 209{ 210 return xp_aligned_extract_addr(pool, addr) >> pool->chunk_shift; 211} 212 213static inline void xp_release(struct xdp_buff_xsk *xskb) 214{ 215 if (xskb->pool->unaligned) 216 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb; 217} 218 219static inline u64 xp_get_handle(struct xdp_buff_xsk *xskb) 220{ 221 u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start; 222 223 offset += xskb->pool->headroom; 224 if (!xskb->pool->unaligned) 225 return xskb->orig_addr + offset; 226 return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT); 227} 228 229#endif /* XSK_BUFF_POOL_H_ */