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