Thomas Gleixner | ddc64d0 | 2019-05-31 01:09:24 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 2 | /* bpf/cpumap.c |
| 3 | * |
| 4 | * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 5 | */ |
| 6 | |
| 7 | /* The 'cpumap' is primarily used as a backend map for XDP BPF helper |
| 8 | * call bpf_redirect_map() and XDP_REDIRECT action, like 'devmap'. |
| 9 | * |
| 10 | * Unlike devmap which redirects XDP frames out another NIC device, |
| 11 | * this map type redirects raw XDP frames to another CPU. The remote |
| 12 | * CPU will do SKB-allocation and call the normal network stack. |
| 13 | * |
| 14 | * This is a scalability and isolation mechanism, that allow |
| 15 | * separating the early driver network XDP layer, from the rest of the |
| 16 | * netstack, and assigning dedicated CPUs for this stage. This |
| 17 | * basically allows for 10G wirespeed pre-filtering via bpf. |
| 18 | */ |
| 19 | #include <linux/bpf.h> |
| 20 | #include <linux/filter.h> |
| 21 | #include <linux/ptr_ring.h> |
Jesper Dangaard Brouer | 5ab073f | 2018-04-17 16:45:26 +0200 | [diff] [blame] | 22 | #include <net/xdp.h> |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 23 | |
| 24 | #include <linux/sched.h> |
| 25 | #include <linux/workqueue.h> |
| 26 | #include <linux/kthread.h> |
| 27 | #include <linux/capability.h> |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 28 | #include <trace/events/xdp.h> |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 29 | |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 30 | #include <linux/netdevice.h> /* netif_receive_skb_core */ |
| 31 | #include <linux/etherdevice.h> /* eth_type_trans */ |
| 32 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 33 | /* General idea: XDP packets getting XDP redirected to another CPU, |
| 34 | * will maximum be stored/queued for one driver ->poll() call. It is |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 35 | * guaranteed that queueing the frame and the flush operation happen on |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 36 | * same CPU. Thus, cpu_map_flush operation can deduct via this_cpu_ptr() |
| 37 | * which queue in bpf_cpu_map_entry contains packets. |
| 38 | */ |
| 39 | |
| 40 | #define CPU_MAP_BULK_SIZE 8 /* 8 == one cacheline on 64-bit archs */ |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 41 | struct bpf_cpu_map_entry; |
| 42 | struct bpf_cpu_map; |
| 43 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 44 | struct xdp_bulk_queue { |
| 45 | void *q[CPU_MAP_BULK_SIZE]; |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 46 | struct list_head flush_node; |
| 47 | struct bpf_cpu_map_entry *obj; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 48 | unsigned int count; |
| 49 | }; |
| 50 | |
| 51 | /* Struct for every remote "destination" CPU in map */ |
| 52 | struct bpf_cpu_map_entry { |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 53 | u32 cpu; /* kthread CPU and map index */ |
| 54 | int map_id; /* Back reference to map */ |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 55 | u32 qsize; /* Queue size placeholder for map lookup */ |
| 56 | |
| 57 | /* XDP can run multiple RX-ring queues, need __percpu enqueue store */ |
| 58 | struct xdp_bulk_queue __percpu *bulkq; |
| 59 | |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 60 | struct bpf_cpu_map *cmap; |
| 61 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 62 | /* Queue with potential multi-producers, and single-consumer kthread */ |
| 63 | struct ptr_ring *queue; |
| 64 | struct task_struct *kthread; |
| 65 | struct work_struct kthread_stop_wq; |
| 66 | |
| 67 | atomic_t refcnt; /* Control when this struct can be free'ed */ |
| 68 | struct rcu_head rcu; |
| 69 | }; |
| 70 | |
| 71 | struct bpf_cpu_map { |
| 72 | struct bpf_map map; |
| 73 | /* Below members specific for map type */ |
| 74 | struct bpf_cpu_map_entry **cpu_map; |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 75 | struct list_head __percpu *flush_list; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 76 | }; |
| 77 | |
Björn Töpel | 4bc188c | 2019-12-19 07:10:00 +0100 | [diff] [blame^] | 78 | static int bq_flush_to_queue(struct xdp_bulk_queue *bq); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 79 | |
| 80 | static struct bpf_map *cpu_map_alloc(union bpf_attr *attr) |
| 81 | { |
| 82 | struct bpf_cpu_map *cmap; |
| 83 | int err = -ENOMEM; |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 84 | int ret, cpu; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 85 | u64 cost; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 86 | |
| 87 | if (!capable(CAP_SYS_ADMIN)) |
| 88 | return ERR_PTR(-EPERM); |
| 89 | |
| 90 | /* check sanity of attributes */ |
| 91 | if (attr->max_entries == 0 || attr->key_size != 4 || |
| 92 | attr->value_size != 4 || attr->map_flags & ~BPF_F_NUMA_NODE) |
| 93 | return ERR_PTR(-EINVAL); |
| 94 | |
| 95 | cmap = kzalloc(sizeof(*cmap), GFP_USER); |
| 96 | if (!cmap) |
| 97 | return ERR_PTR(-ENOMEM); |
| 98 | |
Jakub Kicinski | bd47564 | 2018-01-11 20:29:06 -0800 | [diff] [blame] | 99 | bpf_map_init_from_attr(&cmap->map, attr); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 100 | |
| 101 | /* Pre-limit array size based on NR_CPUS, not final CPU check */ |
| 102 | if (cmap->map.max_entries > NR_CPUS) { |
| 103 | err = -E2BIG; |
| 104 | goto free_cmap; |
| 105 | } |
| 106 | |
| 107 | /* make sure page count doesn't overflow */ |
| 108 | cost = (u64) cmap->map.max_entries * sizeof(struct bpf_cpu_map_entry *); |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 109 | cost += sizeof(struct list_head) * num_possible_cpus(); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 110 | |
| 111 | /* Notice returns -EPERM on if map size is larger than memlock limit */ |
Roman Gushchin | c85d691 | 2019-05-29 18:03:59 -0700 | [diff] [blame] | 112 | ret = bpf_map_charge_init(&cmap->map.memory, cost); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 113 | if (ret) { |
| 114 | err = ret; |
| 115 | goto free_cmap; |
| 116 | } |
| 117 | |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 118 | cmap->flush_list = alloc_percpu(struct list_head); |
| 119 | if (!cmap->flush_list) |
Roman Gushchin | b936ca6 | 2019-05-29 18:03:58 -0700 | [diff] [blame] | 120 | goto free_charge; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 121 | |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 122 | for_each_possible_cpu(cpu) |
| 123 | INIT_LIST_HEAD(per_cpu_ptr(cmap->flush_list, cpu)); |
| 124 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 125 | /* Alloc array for possible remote "destination" CPUs */ |
| 126 | cmap->cpu_map = bpf_map_area_alloc(cmap->map.max_entries * |
| 127 | sizeof(struct bpf_cpu_map_entry *), |
| 128 | cmap->map.numa_node); |
| 129 | if (!cmap->cpu_map) |
| 130 | goto free_percpu; |
| 131 | |
| 132 | return &cmap->map; |
| 133 | free_percpu: |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 134 | free_percpu(cmap->flush_list); |
Roman Gushchin | b936ca6 | 2019-05-29 18:03:58 -0700 | [diff] [blame] | 135 | free_charge: |
| 136 | bpf_map_charge_finish(&cmap->map.memory); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 137 | free_cmap: |
| 138 | kfree(cmap); |
| 139 | return ERR_PTR(err); |
| 140 | } |
| 141 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 142 | static void get_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) |
| 143 | { |
| 144 | atomic_inc(&rcpu->refcnt); |
| 145 | } |
| 146 | |
| 147 | /* called from workqueue, to workaround syscall using preempt_disable */ |
| 148 | static void cpu_map_kthread_stop(struct work_struct *work) |
| 149 | { |
| 150 | struct bpf_cpu_map_entry *rcpu; |
| 151 | |
| 152 | rcpu = container_of(work, struct bpf_cpu_map_entry, kthread_stop_wq); |
| 153 | |
| 154 | /* Wait for flush in __cpu_map_entry_free(), via full RCU barrier, |
| 155 | * as it waits until all in-flight call_rcu() callbacks complete. |
| 156 | */ |
| 157 | rcu_barrier(); |
| 158 | |
| 159 | /* kthread_stop will wake_up_process and wait for it to complete */ |
| 160 | kthread_stop(rcpu->kthread); |
| 161 | } |
| 162 | |
Wei Yongjun | 0fe875c | 2018-01-16 11:27:05 +0000 | [diff] [blame] | 163 | static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu, |
Jesper Dangaard Brouer | 8f0504a9 | 2019-04-12 17:07:43 +0200 | [diff] [blame] | 164 | struct xdp_frame *xdpf, |
| 165 | struct sk_buff *skb) |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 166 | { |
Jesper Dangaard Brouer | 676e4a6 | 2019-03-29 10:18:00 +0100 | [diff] [blame] | 167 | unsigned int hard_start_headroom; |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 168 | unsigned int frame_size; |
| 169 | void *pkt_data_start; |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 170 | |
Jesper Dangaard Brouer | 676e4a6 | 2019-03-29 10:18:00 +0100 | [diff] [blame] | 171 | /* Part of headroom was reserved to xdpf */ |
| 172 | hard_start_headroom = sizeof(struct xdp_frame) + xdpf->headroom; |
| 173 | |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 174 | /* build_skb need to place skb_shared_info after SKB end, and |
| 175 | * also want to know the memory "truesize". Thus, need to |
| 176 | * know the memory frame size backing xdp_buff. |
| 177 | * |
| 178 | * XDP was designed to have PAGE_SIZE frames, but this |
| 179 | * assumption is not longer true with ixgbe and i40e. It |
| 180 | * would be preferred to set frame_size to 2048 or 4096 |
| 181 | * depending on the driver. |
| 182 | * frame_size = 2048; |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 183 | * frame_len = frame_size - sizeof(*xdp_frame); |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 184 | * |
| 185 | * Instead, with info avail, skb_shared_info in placed after |
| 186 | * packet len. This, unfortunately fakes the truesize. |
| 187 | * Another disadvantage of this approach, the skb_shared_info |
| 188 | * is not at a fixed memory location, with mixed length |
| 189 | * packets, which is bad for cache-line hotness. |
| 190 | */ |
Jesper Dangaard Brouer | 676e4a6 | 2019-03-29 10:18:00 +0100 | [diff] [blame] | 191 | frame_size = SKB_DATA_ALIGN(xdpf->len + hard_start_headroom) + |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 192 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
| 193 | |
Jesper Dangaard Brouer | 676e4a6 | 2019-03-29 10:18:00 +0100 | [diff] [blame] | 194 | pkt_data_start = xdpf->data - hard_start_headroom; |
Jesper Dangaard Brouer | 8f0504a9 | 2019-04-12 17:07:43 +0200 | [diff] [blame] | 195 | skb = build_skb_around(skb, pkt_data_start, frame_size); |
| 196 | if (unlikely(!skb)) |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 197 | return NULL; |
| 198 | |
Jesper Dangaard Brouer | 676e4a6 | 2019-03-29 10:18:00 +0100 | [diff] [blame] | 199 | skb_reserve(skb, hard_start_headroom); |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 200 | __skb_put(skb, xdpf->len); |
| 201 | if (xdpf->metasize) |
| 202 | skb_metadata_set(skb, xdpf->metasize); |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 203 | |
| 204 | /* Essential SKB info: protocol and skb->dev */ |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 205 | skb->protocol = eth_type_trans(skb, xdpf->dev_rx); |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 206 | |
| 207 | /* Optional SKB info, currently missing: |
| 208 | * - HW checksum info (skb->ip_summed) |
| 209 | * - HW RX hash (skb_set_hash) |
| 210 | * - RX ring dev queue index (skb_record_rx_queue) |
| 211 | */ |
| 212 | |
Jesper Dangaard Brouer | 6bf071b | 2019-06-18 15:05:27 +0200 | [diff] [blame] | 213 | /* Until page_pool get SKB return path, release DMA here */ |
| 214 | xdp_release_frame(xdpf); |
| 215 | |
Jesper Dangaard Brouer | 676e4a6 | 2019-03-29 10:18:00 +0100 | [diff] [blame] | 216 | /* Allow SKB to reuse area used by xdp_frame */ |
| 217 | xdp_scrub_frame(xdpf); |
| 218 | |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 219 | return skb; |
| 220 | } |
| 221 | |
Jesper Dangaard Brouer | 5ab073f | 2018-04-17 16:45:26 +0200 | [diff] [blame] | 222 | static void __cpu_map_ring_cleanup(struct ptr_ring *ring) |
| 223 | { |
| 224 | /* The tear-down procedure should have made sure that queue is |
| 225 | * empty. See __cpu_map_entry_replace() and work-queue |
| 226 | * invoked cpu_map_kthread_stop(). Catch any broken behaviour |
| 227 | * gracefully and warn once. |
| 228 | */ |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 229 | struct xdp_frame *xdpf; |
Jesper Dangaard Brouer | 5ab073f | 2018-04-17 16:45:26 +0200 | [diff] [blame] | 230 | |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 231 | while ((xdpf = ptr_ring_consume(ring))) |
| 232 | if (WARN_ON_ONCE(xdpf)) |
Jesper Dangaard Brouer | 0399309 | 2018-04-17 16:46:32 +0200 | [diff] [blame] | 233 | xdp_return_frame(xdpf); |
Jesper Dangaard Brouer | 5ab073f | 2018-04-17 16:45:26 +0200 | [diff] [blame] | 234 | } |
| 235 | |
| 236 | static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) |
| 237 | { |
| 238 | if (atomic_dec_and_test(&rcpu->refcnt)) { |
| 239 | /* The queue should be empty at this point */ |
| 240 | __cpu_map_ring_cleanup(rcpu->queue); |
| 241 | ptr_ring_cleanup(rcpu->queue, NULL); |
| 242 | kfree(rcpu->queue); |
| 243 | kfree(rcpu); |
| 244 | } |
| 245 | } |
| 246 | |
Jesper Dangaard Brouer | 7736182 | 2019-04-12 17:07:32 +0200 | [diff] [blame] | 247 | #define CPUMAP_BATCH 8 |
| 248 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 249 | static int cpu_map_kthread_run(void *data) |
| 250 | { |
| 251 | struct bpf_cpu_map_entry *rcpu = data; |
| 252 | |
| 253 | set_current_state(TASK_INTERRUPTIBLE); |
| 254 | |
| 255 | /* When kthread gives stop order, then rcpu have been disconnected |
| 256 | * from map, thus no new packets can enter. Remaining in-flight |
| 257 | * per CPU stored packets are flushed to this queue. Wait honoring |
| 258 | * kthread_stop signal until queue is empty. |
| 259 | */ |
| 260 | while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) { |
Jesper Dangaard Brouer | 7736182 | 2019-04-12 17:07:32 +0200 | [diff] [blame] | 261 | unsigned int drops = 0, sched = 0; |
| 262 | void *frames[CPUMAP_BATCH]; |
Jesper Dangaard Brouer | 8f0504a9 | 2019-04-12 17:07:43 +0200 | [diff] [blame] | 263 | void *skbs[CPUMAP_BATCH]; |
| 264 | gfp_t gfp = __GFP_ZERO | GFP_ATOMIC; |
| 265 | int i, n, m; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 266 | |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 267 | /* Release CPU reschedule checks */ |
| 268 | if (__ptr_ring_empty(rcpu->queue)) { |
Jesper Dangaard Brouer | 3174946 | 2017-10-23 19:39:28 +0200 | [diff] [blame] | 269 | set_current_state(TASK_INTERRUPTIBLE); |
| 270 | /* Recheck to avoid lost wake-up */ |
| 271 | if (__ptr_ring_empty(rcpu->queue)) { |
| 272 | schedule(); |
| 273 | sched = 1; |
| 274 | } else { |
| 275 | __set_current_state(TASK_RUNNING); |
| 276 | } |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 277 | } else { |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 278 | sched = cond_resched(); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 279 | } |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 280 | |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 281 | /* |
| 282 | * The bpf_cpu_map_entry is single consumer, with this |
| 283 | * kthread CPU pinned. Lockless access to ptr_ring |
| 284 | * consume side valid as no-resize allowed of queue. |
| 285 | */ |
Jesper Dangaard Brouer | 7736182 | 2019-04-12 17:07:32 +0200 | [diff] [blame] | 286 | n = ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH); |
Jesper Dangaard Brouer | 86d2314 | 2019-04-12 17:07:48 +0200 | [diff] [blame] | 287 | |
| 288 | for (i = 0; i < n; i++) { |
| 289 | void *f = frames[i]; |
| 290 | struct page *page = virt_to_page(f); |
| 291 | |
| 292 | /* Bring struct page memory area to curr CPU. Read by |
| 293 | * build_skb_around via page_is_pfmemalloc(), and when |
| 294 | * freed written by page_frag_free call. |
| 295 | */ |
| 296 | prefetchw(page); |
| 297 | } |
| 298 | |
Jesper Dangaard Brouer | 8f0504a9 | 2019-04-12 17:07:43 +0200 | [diff] [blame] | 299 | m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, n, skbs); |
| 300 | if (unlikely(m == 0)) { |
| 301 | for (i = 0; i < n; i++) |
| 302 | skbs[i] = NULL; /* effect: xdp_return_frame */ |
| 303 | drops = n; |
| 304 | } |
Jesper Dangaard Brouer | 7736182 | 2019-04-12 17:07:32 +0200 | [diff] [blame] | 305 | |
| 306 | local_bh_disable(); |
| 307 | for (i = 0; i < n; i++) { |
| 308 | struct xdp_frame *xdpf = frames[i]; |
Jesper Dangaard Brouer | 8f0504a9 | 2019-04-12 17:07:43 +0200 | [diff] [blame] | 309 | struct sk_buff *skb = skbs[i]; |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 310 | int ret; |
| 311 | |
Jesper Dangaard Brouer | 8f0504a9 | 2019-04-12 17:07:43 +0200 | [diff] [blame] | 312 | skb = cpu_map_build_skb(rcpu, xdpf, skb); |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 313 | if (!skb) { |
Jesper Dangaard Brouer | 0399309 | 2018-04-17 16:46:32 +0200 | [diff] [blame] | 314 | xdp_return_frame(xdpf); |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 315 | continue; |
| 316 | } |
| 317 | |
| 318 | /* Inject into network stack */ |
| 319 | ret = netif_receive_skb_core(skb); |
| 320 | if (ret == NET_RX_DROP) |
| 321 | drops++; |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 322 | } |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 323 | /* Feedback loop via tracepoint */ |
Jesper Dangaard Brouer | 7736182 | 2019-04-12 17:07:32 +0200 | [diff] [blame] | 324 | trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched); |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 325 | |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 326 | local_bh_enable(); /* resched point, may call do_softirq() */ |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 327 | } |
| 328 | __set_current_state(TASK_RUNNING); |
| 329 | |
| 330 | put_cpu_map_entry(rcpu); |
| 331 | return 0; |
| 332 | } |
| 333 | |
Wei Yongjun | 0fe875c | 2018-01-16 11:27:05 +0000 | [diff] [blame] | 334 | static struct bpf_cpu_map_entry *__cpu_map_entry_alloc(u32 qsize, u32 cpu, |
| 335 | int map_id) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 336 | { |
Jason Wang | 7fc17e9 | 2018-02-14 22:17:34 +0800 | [diff] [blame] | 337 | gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 338 | struct bpf_cpu_map_entry *rcpu; |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 339 | struct xdp_bulk_queue *bq; |
| 340 | int numa, err, i; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 341 | |
| 342 | /* Have map->numa_node, but choose node of redirect target CPU */ |
| 343 | numa = cpu_to_node(cpu); |
| 344 | |
| 345 | rcpu = kzalloc_node(sizeof(*rcpu), gfp, numa); |
| 346 | if (!rcpu) |
| 347 | return NULL; |
| 348 | |
| 349 | /* Alloc percpu bulkq */ |
| 350 | rcpu->bulkq = __alloc_percpu_gfp(sizeof(*rcpu->bulkq), |
| 351 | sizeof(void *), gfp); |
| 352 | if (!rcpu->bulkq) |
| 353 | goto free_rcu; |
| 354 | |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 355 | for_each_possible_cpu(i) { |
| 356 | bq = per_cpu_ptr(rcpu->bulkq, i); |
| 357 | bq->obj = rcpu; |
| 358 | } |
| 359 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 360 | /* Alloc queue */ |
| 361 | rcpu->queue = kzalloc_node(sizeof(*rcpu->queue), gfp, numa); |
| 362 | if (!rcpu->queue) |
| 363 | goto free_bulkq; |
| 364 | |
| 365 | err = ptr_ring_init(rcpu->queue, qsize, gfp); |
| 366 | if (err) |
| 367 | goto free_queue; |
| 368 | |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 369 | rcpu->cpu = cpu; |
| 370 | rcpu->map_id = map_id; |
| 371 | rcpu->qsize = qsize; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 372 | |
| 373 | /* Setup kthread */ |
| 374 | rcpu->kthread = kthread_create_on_node(cpu_map_kthread_run, rcpu, numa, |
| 375 | "cpumap/%d/map:%d", cpu, map_id); |
| 376 | if (IS_ERR(rcpu->kthread)) |
| 377 | goto free_ptr_ring; |
| 378 | |
| 379 | get_cpu_map_entry(rcpu); /* 1-refcnt for being in cmap->cpu_map[] */ |
| 380 | get_cpu_map_entry(rcpu); /* 1-refcnt for kthread */ |
| 381 | |
| 382 | /* Make sure kthread runs on a single CPU */ |
| 383 | kthread_bind(rcpu->kthread, cpu); |
| 384 | wake_up_process(rcpu->kthread); |
| 385 | |
| 386 | return rcpu; |
| 387 | |
| 388 | free_ptr_ring: |
| 389 | ptr_ring_cleanup(rcpu->queue, NULL); |
| 390 | free_queue: |
| 391 | kfree(rcpu->queue); |
| 392 | free_bulkq: |
| 393 | free_percpu(rcpu->bulkq); |
| 394 | free_rcu: |
| 395 | kfree(rcpu); |
| 396 | return NULL; |
| 397 | } |
| 398 | |
Wei Yongjun | 0fe875c | 2018-01-16 11:27:05 +0000 | [diff] [blame] | 399 | static void __cpu_map_entry_free(struct rcu_head *rcu) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 400 | { |
| 401 | struct bpf_cpu_map_entry *rcpu; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 402 | |
| 403 | /* This cpu_map_entry have been disconnected from map and one |
| 404 | * RCU graze-period have elapsed. Thus, XDP cannot queue any |
| 405 | * new packets and cannot change/set flush_needed that can |
| 406 | * find this entry. |
| 407 | */ |
| 408 | rcpu = container_of(rcu, struct bpf_cpu_map_entry, rcu); |
| 409 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 410 | free_percpu(rcpu->bulkq); |
| 411 | /* Cannot kthread_stop() here, last put free rcpu resources */ |
| 412 | put_cpu_map_entry(rcpu); |
| 413 | } |
| 414 | |
| 415 | /* After xchg pointer to bpf_cpu_map_entry, use the call_rcu() to |
| 416 | * ensure any driver rcu critical sections have completed, but this |
| 417 | * does not guarantee a flush has happened yet. Because driver side |
| 418 | * rcu_read_lock/unlock only protects the running XDP program. The |
| 419 | * atomic xchg and NULL-ptr check in __cpu_map_flush() makes sure a |
| 420 | * pending flush op doesn't fail. |
| 421 | * |
| 422 | * The bpf_cpu_map_entry is still used by the kthread, and there can |
| 423 | * still be pending packets (in queue and percpu bulkq). A refcnt |
| 424 | * makes sure to last user (kthread_stop vs. call_rcu) free memory |
| 425 | * resources. |
| 426 | * |
| 427 | * The rcu callback __cpu_map_entry_free flush remaining packets in |
| 428 | * percpu bulkq to queue. Due to caller map_delete_elem() disable |
| 429 | * preemption, cannot call kthread_stop() to make sure queue is empty. |
| 430 | * Instead a work_queue is started for stopping kthread, |
| 431 | * cpu_map_kthread_stop, which waits for an RCU graze period before |
| 432 | * stopping kthread, emptying the queue. |
| 433 | */ |
Wei Yongjun | 0fe875c | 2018-01-16 11:27:05 +0000 | [diff] [blame] | 434 | static void __cpu_map_entry_replace(struct bpf_cpu_map *cmap, |
| 435 | u32 key_cpu, struct bpf_cpu_map_entry *rcpu) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 436 | { |
| 437 | struct bpf_cpu_map_entry *old_rcpu; |
| 438 | |
| 439 | old_rcpu = xchg(&cmap->cpu_map[key_cpu], rcpu); |
| 440 | if (old_rcpu) { |
| 441 | call_rcu(&old_rcpu->rcu, __cpu_map_entry_free); |
| 442 | INIT_WORK(&old_rcpu->kthread_stop_wq, cpu_map_kthread_stop); |
| 443 | schedule_work(&old_rcpu->kthread_stop_wq); |
| 444 | } |
| 445 | } |
| 446 | |
Wei Yongjun | 0fe875c | 2018-01-16 11:27:05 +0000 | [diff] [blame] | 447 | static int cpu_map_delete_elem(struct bpf_map *map, void *key) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 448 | { |
| 449 | struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); |
| 450 | u32 key_cpu = *(u32 *)key; |
| 451 | |
| 452 | if (key_cpu >= map->max_entries) |
| 453 | return -EINVAL; |
| 454 | |
| 455 | /* notice caller map_delete_elem() use preempt_disable() */ |
| 456 | __cpu_map_entry_replace(cmap, key_cpu, NULL); |
| 457 | return 0; |
| 458 | } |
| 459 | |
Wei Yongjun | 0fe875c | 2018-01-16 11:27:05 +0000 | [diff] [blame] | 460 | static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value, |
| 461 | u64 map_flags) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 462 | { |
| 463 | struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); |
| 464 | struct bpf_cpu_map_entry *rcpu; |
| 465 | |
| 466 | /* Array index key correspond to CPU number */ |
| 467 | u32 key_cpu = *(u32 *)key; |
| 468 | /* Value is the queue size */ |
| 469 | u32 qsize = *(u32 *)value; |
| 470 | |
| 471 | if (unlikely(map_flags > BPF_EXIST)) |
| 472 | return -EINVAL; |
| 473 | if (unlikely(key_cpu >= cmap->map.max_entries)) |
| 474 | return -E2BIG; |
| 475 | if (unlikely(map_flags == BPF_NOEXIST)) |
| 476 | return -EEXIST; |
| 477 | if (unlikely(qsize > 16384)) /* sanity limit on qsize */ |
| 478 | return -EOVERFLOW; |
| 479 | |
| 480 | /* Make sure CPU is a valid possible cpu */ |
| 481 | if (!cpu_possible(key_cpu)) |
| 482 | return -ENODEV; |
| 483 | |
| 484 | if (qsize == 0) { |
| 485 | rcpu = NULL; /* Same as deleting */ |
| 486 | } else { |
| 487 | /* Updating qsize cause re-allocation of bpf_cpu_map_entry */ |
| 488 | rcpu = __cpu_map_entry_alloc(qsize, key_cpu, map->id); |
| 489 | if (!rcpu) |
| 490 | return -ENOMEM; |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 491 | rcpu->cmap = cmap; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 492 | } |
| 493 | rcu_read_lock(); |
| 494 | __cpu_map_entry_replace(cmap, key_cpu, rcpu); |
| 495 | rcu_read_unlock(); |
| 496 | return 0; |
| 497 | } |
| 498 | |
Wei Yongjun | 0fe875c | 2018-01-16 11:27:05 +0000 | [diff] [blame] | 499 | static void cpu_map_free(struct bpf_map *map) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 500 | { |
| 501 | struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 502 | u32 i; |
| 503 | |
| 504 | /* At this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, |
| 505 | * so the bpf programs (can be more than one that used this map) were |
| 506 | * disconnected from events. Wait for outstanding critical sections in |
| 507 | * these programs to complete. The rcu critical section only guarantees |
| 508 | * no further "XDP/bpf-side" reads against bpf_cpu_map->cpu_map. |
| 509 | * It does __not__ ensure pending flush operations (if any) are |
| 510 | * complete. |
| 511 | */ |
Daniel Borkmann | f6069b9 | 2018-08-17 23:26:14 +0200 | [diff] [blame] | 512 | |
| 513 | bpf_clear_redirect_map(map); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 514 | synchronize_rcu(); |
| 515 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 516 | /* For cpu_map the remote CPUs can still be using the entries |
| 517 | * (struct bpf_cpu_map_entry). |
| 518 | */ |
| 519 | for (i = 0; i < cmap->map.max_entries; i++) { |
| 520 | struct bpf_cpu_map_entry *rcpu; |
| 521 | |
| 522 | rcpu = READ_ONCE(cmap->cpu_map[i]); |
| 523 | if (!rcpu) |
| 524 | continue; |
| 525 | |
| 526 | /* bq flush and cleanup happens after RCU graze-period */ |
| 527 | __cpu_map_entry_replace(cmap, i, NULL); /* call_rcu */ |
| 528 | } |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 529 | free_percpu(cmap->flush_list); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 530 | bpf_map_area_free(cmap->cpu_map); |
| 531 | kfree(cmap); |
| 532 | } |
| 533 | |
| 534 | struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key) |
| 535 | { |
| 536 | struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); |
| 537 | struct bpf_cpu_map_entry *rcpu; |
| 538 | |
| 539 | if (key >= map->max_entries) |
| 540 | return NULL; |
| 541 | |
| 542 | rcpu = READ_ONCE(cmap->cpu_map[key]); |
| 543 | return rcpu; |
| 544 | } |
| 545 | |
| 546 | static void *cpu_map_lookup_elem(struct bpf_map *map, void *key) |
| 547 | { |
| 548 | struct bpf_cpu_map_entry *rcpu = |
| 549 | __cpu_map_lookup_elem(map, *(u32 *)key); |
| 550 | |
| 551 | return rcpu ? &rcpu->qsize : NULL; |
| 552 | } |
| 553 | |
| 554 | static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key) |
| 555 | { |
| 556 | struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); |
| 557 | u32 index = key ? *(u32 *)key : U32_MAX; |
| 558 | u32 *next = next_key; |
| 559 | |
| 560 | if (index >= cmap->map.max_entries) { |
| 561 | *next = 0; |
| 562 | return 0; |
| 563 | } |
| 564 | |
| 565 | if (index == cmap->map.max_entries - 1) |
| 566 | return -ENOENT; |
| 567 | *next = index + 1; |
| 568 | return 0; |
| 569 | } |
| 570 | |
| 571 | const struct bpf_map_ops cpu_map_ops = { |
| 572 | .map_alloc = cpu_map_alloc, |
| 573 | .map_free = cpu_map_free, |
| 574 | .map_delete_elem = cpu_map_delete_elem, |
| 575 | .map_update_elem = cpu_map_update_elem, |
| 576 | .map_lookup_elem = cpu_map_lookup_elem, |
| 577 | .map_get_next_key = cpu_map_get_next_key, |
Daniel Borkmann | e8d2bec | 2018-08-12 01:59:17 +0200 | [diff] [blame] | 578 | .map_check_btf = map_check_no_btf, |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 579 | }; |
| 580 | |
Björn Töpel | 4bc188c | 2019-12-19 07:10:00 +0100 | [diff] [blame^] | 581 | static int bq_flush_to_queue(struct xdp_bulk_queue *bq) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 582 | { |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 583 | struct bpf_cpu_map_entry *rcpu = bq->obj; |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 584 | unsigned int processed = 0, drops = 0; |
| 585 | const int to_cpu = rcpu->cpu; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 586 | struct ptr_ring *q; |
| 587 | int i; |
| 588 | |
| 589 | if (unlikely(!bq->count)) |
| 590 | return 0; |
| 591 | |
| 592 | q = rcpu->queue; |
| 593 | spin_lock(&q->producer_lock); |
| 594 | |
| 595 | for (i = 0; i < bq->count; i++) { |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 596 | struct xdp_frame *xdpf = bq->q[i]; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 597 | int err; |
| 598 | |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 599 | err = __ptr_ring_produce(q, xdpf); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 600 | if (err) { |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 601 | drops++; |
Björn Töpel | 4bc188c | 2019-12-19 07:10:00 +0100 | [diff] [blame^] | 602 | xdp_return_frame_rx_napi(xdpf); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 603 | } |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 604 | processed++; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 605 | } |
| 606 | bq->count = 0; |
| 607 | spin_unlock(&q->producer_lock); |
| 608 | |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 609 | __list_del_clearprev(&bq->flush_node); |
| 610 | |
Jesper Dangaard Brouer | f9419f7 | 2017-10-16 12:19:44 +0200 | [diff] [blame] | 611 | /* Feedback loop via tracepoints */ |
| 612 | trace_xdp_cpumap_enqueue(rcpu->map_id, processed, drops, to_cpu); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 613 | return 0; |
| 614 | } |
| 615 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 616 | /* Runs under RCU-read-side, plus in softirq under NAPI protection. |
| 617 | * Thus, safe percpu variable access. |
| 618 | */ |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 619 | static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf) |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 620 | { |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 621 | struct list_head *flush_list = this_cpu_ptr(rcpu->cmap->flush_list); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 622 | struct xdp_bulk_queue *bq = this_cpu_ptr(rcpu->bulkq); |
| 623 | |
| 624 | if (unlikely(bq->count == CPU_MAP_BULK_SIZE)) |
Björn Töpel | 4bc188c | 2019-12-19 07:10:00 +0100 | [diff] [blame^] | 625 | bq_flush_to_queue(bq); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 626 | |
| 627 | /* Notice, xdp_buff/page MUST be queued here, long enough for |
| 628 | * driver to code invoking us to finished, due to driver |
| 629 | * (e.g. ixgbe) recycle tricks based on page-refcnt. |
| 630 | * |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 631 | * Thus, incoming xdp_frame is always queued here (else we race |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 632 | * with another CPU on page-refcnt and remaining driver code). |
| 633 | * Queue time is very short, as driver will invoke flush |
| 634 | * operation, when completing napi->poll call. |
| 635 | */ |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 636 | bq->q[bq->count++] = xdpf; |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 637 | |
| 638 | if (!bq->flush_node.prev) |
| 639 | list_add(&bq->flush_node, flush_list); |
| 640 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 641 | return 0; |
| 642 | } |
| 643 | |
Jesper Dangaard Brouer | 9c270af | 2017-10-16 12:19:34 +0200 | [diff] [blame] | 644 | int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, |
| 645 | struct net_device *dev_rx) |
| 646 | { |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 647 | struct xdp_frame *xdpf; |
Jesper Dangaard Brouer | 9c270af | 2017-10-16 12:19:34 +0200 | [diff] [blame] | 648 | |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 649 | xdpf = convert_to_xdp_frame(xdp); |
| 650 | if (unlikely(!xdpf)) |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 651 | return -EOVERFLOW; |
Jesper Dangaard Brouer | 9c270af | 2017-10-16 12:19:34 +0200 | [diff] [blame] | 652 | |
Jesper Dangaard Brouer | 1c601d8 | 2017-10-16 12:19:39 +0200 | [diff] [blame] | 653 | /* Info needed when constructing SKB on remote CPU */ |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 654 | xdpf->dev_rx = dev_rx; |
Jesper Dangaard Brouer | 9c270af | 2017-10-16 12:19:34 +0200 | [diff] [blame] | 655 | |
Jesper Dangaard Brouer | 70280ed | 2018-04-17 16:45:57 +0200 | [diff] [blame] | 656 | bq_enqueue(rcpu, xdpf); |
Jesper Dangaard Brouer | 9c270af | 2017-10-16 12:19:34 +0200 | [diff] [blame] | 657 | return 0; |
| 658 | } |
| 659 | |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 660 | void __cpu_map_flush(struct bpf_map *map) |
| 661 | { |
| 662 | struct bpf_cpu_map *cmap = container_of(map, struct bpf_cpu_map, map); |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 663 | struct list_head *flush_list = this_cpu_ptr(cmap->flush_list); |
| 664 | struct xdp_bulk_queue *bq, *tmp; |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 665 | |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 666 | list_for_each_entry_safe(bq, tmp, flush_list, flush_node) { |
Björn Töpel | 4bc188c | 2019-12-19 07:10:00 +0100 | [diff] [blame^] | 667 | bq_flush_to_queue(bq); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 668 | |
| 669 | /* If already running, costs spin_lock_irqsave + smb_mb */ |
Toke Høiland-Jørgensen | d5df283 | 2019-06-28 11:12:34 +0200 | [diff] [blame] | 670 | wake_up_process(bq->obj->kthread); |
Jesper Dangaard Brouer | 6710e11 | 2017-10-16 12:19:28 +0200 | [diff] [blame] | 671 | } |
| 672 | } |