1 /* Broadcom NetXtreme-C/E network driver. 2 * 3 * Copyright (c) 2016-2017 Broadcom Limited 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation. 8 */ 9 #include <linux/kernel.h> 10 #include <linux/errno.h> 11 #include <linux/pci.h> 12 #include <linux/netdevice.h> 13 #include <linux/etherdevice.h> 14 #include <linux/if_vlan.h> 15 #include <linux/bpf.h> 16 #include <linux/bpf_trace.h> 17 #include <linux/filter.h> 18 #include <net/page_pool.h> 19 #include "bnxt_hsi.h" 20 #include "bnxt.h" 21 #include "bnxt_xdp.h" 22 23 struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp, 24 struct bnxt_tx_ring_info *txr, 25 dma_addr_t mapping, u32 len) 26 { 27 struct bnxt_sw_tx_bd *tx_buf; 28 struct tx_bd *txbd; 29 u32 flags; 30 u16 prod; 31 32 prod = txr->tx_prod; 33 tx_buf = &txr->tx_buf_ring[prod]; 34 35 txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)]; 36 flags = (len << TX_BD_LEN_SHIFT) | (1 << TX_BD_FLAGS_BD_CNT_SHIFT) | 37 TX_BD_FLAGS_PACKET_END | bnxt_lhint_arr[len >> 9]; 38 txbd->tx_bd_len_flags_type = cpu_to_le32(flags); 39 txbd->tx_bd_opaque = prod; 40 txbd->tx_bd_haddr = cpu_to_le64(mapping); 41 42 prod = NEXT_TX(prod); 43 txr->tx_prod = prod; 44 return tx_buf; 45 } 46 47 static void __bnxt_xmit_xdp(struct bnxt *bp, struct bnxt_tx_ring_info *txr, 48 dma_addr_t mapping, u32 len, u16 rx_prod) 49 { 50 struct bnxt_sw_tx_bd *tx_buf; 51 52 tx_buf = bnxt_xmit_bd(bp, txr, mapping, len); 53 tx_buf->rx_prod = rx_prod; 54 tx_buf->action = XDP_TX; 55 } 56 57 static void __bnxt_xmit_xdp_redirect(struct bnxt *bp, 58 struct bnxt_tx_ring_info *txr, 59 dma_addr_t mapping, u32 len, 60 struct xdp_frame *xdpf) 61 { 62 struct bnxt_sw_tx_bd *tx_buf; 63 64 tx_buf = bnxt_xmit_bd(bp, txr, mapping, len); 65 tx_buf->action = XDP_REDIRECT; 66 tx_buf->xdpf = xdpf; 67 dma_unmap_addr_set(tx_buf, mapping, mapping); 68 dma_unmap_len_set(tx_buf, len, 0); 69 } 70 71 void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) 72 { 73 struct bnxt_tx_ring_info *txr = bnapi->tx_ring; 74 struct bnxt_rx_ring_info *rxr = bnapi->rx_ring; 75 bool rx_doorbell_needed = false; 76 struct bnxt_sw_tx_bd *tx_buf; 77 u16 tx_cons = txr->tx_cons; 78 u16 last_tx_cons = tx_cons; 79 int i; 80 81 for (i = 0; i < nr_pkts; i++) { 82 tx_buf = &txr->tx_buf_ring[tx_cons]; 83 84 if (tx_buf->action == XDP_REDIRECT) { 85 struct pci_dev *pdev = bp->pdev; 86 87 dma_unmap_single(&pdev->dev, 88 dma_unmap_addr(tx_buf, mapping), 89 dma_unmap_len(tx_buf, len), 90 PCI_DMA_TODEVICE); 91 xdp_return_frame(tx_buf->xdpf); 92 tx_buf->action = 0; 93 tx_buf->xdpf = NULL; 94 } else if (tx_buf->action == XDP_TX) { 95 rx_doorbell_needed = true; 96 last_tx_cons = tx_cons; 97 } 98 tx_cons = NEXT_TX(tx_cons); 99 } 100 txr->tx_cons = tx_cons; 101 if (rx_doorbell_needed) { 102 tx_buf = &txr->tx_buf_ring[last_tx_cons]; 103 bnxt_db_write(bp, &rxr->rx_db, tx_buf->rx_prod); 104 } 105 } 106 107 /* returns the following: 108 * true - packet consumed by XDP and new buffer is allocated. 109 * false - packet should be passed to the stack. 110 */ 111 bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons, 112 struct page *page, u8 **data_ptr, unsigned int *len, u8 *event) 113 { 114 struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog); 115 struct bnxt_tx_ring_info *txr; 116 struct bnxt_sw_rx_bd *rx_buf; 117 struct pci_dev *pdev; 118 struct xdp_buff xdp; 119 dma_addr_t mapping; 120 void *orig_data; 121 u32 tx_avail; 122 u32 offset; 123 u32 act; 124 125 if (!xdp_prog) 126 return false; 127 128 pdev = bp->pdev; 129 rx_buf = &rxr->rx_buf_ring[cons]; 130 offset = bp->rx_offset; 131 132 mapping = rx_buf->mapping - bp->rx_dma_offset; 133 dma_sync_single_for_cpu(&pdev->dev, mapping + offset, *len, bp->rx_dir); 134 135 txr = rxr->bnapi->tx_ring; 136 /* BNXT_RX_PAGE_MODE(bp) when XDP enabled */ 137 xdp_init_buff(&xdp, PAGE_SIZE, &rxr->xdp_rxq); 138 xdp_prepare_buff(&xdp, *data_ptr - offset, offset, *len, false); 139 orig_data = xdp.data; 140 141 rcu_read_lock(); 142 act = bpf_prog_run_xdp(xdp_prog, &xdp); 143 rcu_read_unlock(); 144 145 tx_avail = bnxt_tx_avail(bp, txr); 146 /* If the tx ring is not full, we must not update the rx producer yet 147 * because we may still be transmitting on some BDs. 148 */ 149 if (tx_avail != bp->tx_ring_size) 150 *event &= ~BNXT_RX_EVENT; 151 152 *len = xdp.data_end - xdp.data; 153 if (orig_data != xdp.data) { 154 offset = xdp.data - xdp.data_hard_start; 155 *data_ptr = xdp.data_hard_start + offset; 156 } 157 switch (act) { 158 case XDP_PASS: 159 return false; 160 161 case XDP_TX: 162 if (tx_avail < 1) { 163 trace_xdp_exception(bp->dev, xdp_prog, act); 164 bnxt_reuse_rx_data(rxr, cons, page); 165 return true; 166 } 167 168 *event = BNXT_TX_EVENT; 169 dma_sync_single_for_device(&pdev->dev, mapping + offset, *len, 170 bp->rx_dir); 171 __bnxt_xmit_xdp(bp, txr, mapping + offset, *len, 172 NEXT_RX(rxr->rx_prod)); 173 bnxt_reuse_rx_data(rxr, cons, page); 174 return true; 175 case XDP_REDIRECT: 176 /* if we are calling this here then we know that the 177 * redirect is coming from a frame received by the 178 * bnxt_en driver. 179 */ 180 dma_unmap_page_attrs(&pdev->dev, mapping, 181 PAGE_SIZE, bp->rx_dir, 182 DMA_ATTR_WEAK_ORDERING); 183 184 /* if we are unable to allocate a new buffer, abort and reuse */ 185 if (bnxt_alloc_rx_data(bp, rxr, rxr->rx_prod, GFP_ATOMIC)) { 186 trace_xdp_exception(bp->dev, xdp_prog, act); 187 bnxt_reuse_rx_data(rxr, cons, page); 188 return true; 189 } 190 191 if (xdp_do_redirect(bp->dev, &xdp, xdp_prog)) { 192 trace_xdp_exception(bp->dev, xdp_prog, act); 193 page_pool_recycle_direct(rxr->page_pool, page); 194 return true; 195 } 196 197 *event |= BNXT_REDIRECT_EVENT; 198 break; 199 default: 200 bpf_warn_invalid_xdp_action(act); 201 fallthrough; 202 case XDP_ABORTED: 203 trace_xdp_exception(bp->dev, xdp_prog, act); 204 fallthrough; 205 case XDP_DROP: 206 bnxt_reuse_rx_data(rxr, cons, page); 207 break; 208 } 209 return true; 210 } 211 212 int bnxt_xdp_xmit(struct net_device *dev, int num_frames, 213 struct xdp_frame **frames, u32 flags) 214 { 215 struct bnxt *bp = netdev_priv(dev); 216 struct bpf_prog *xdp_prog = READ_ONCE(bp->xdp_prog); 217 struct pci_dev *pdev = bp->pdev; 218 struct bnxt_tx_ring_info *txr; 219 dma_addr_t mapping; 220 int nxmit = 0; 221 int ring; 222 int i; 223 224 if (!test_bit(BNXT_STATE_OPEN, &bp->state) || 225 !bp->tx_nr_rings_xdp || 226 !xdp_prog) 227 return -EINVAL; 228 229 ring = smp_processor_id() % bp->tx_nr_rings_xdp; 230 txr = &bp->tx_ring[ring]; 231 232 for (i = 0; i < num_frames; i++) { 233 struct xdp_frame *xdp = frames[i]; 234 235 if (!txr || !bnxt_tx_avail(bp, txr) || 236 !(bp->bnapi[ring]->flags & BNXT_NAPI_FLAG_XDP)) 237 break; 238 239 mapping = dma_map_single(&pdev->dev, xdp->data, xdp->len, 240 DMA_TO_DEVICE); 241 242 if (dma_mapping_error(&pdev->dev, mapping)) 243 break; 244 245 __bnxt_xmit_xdp_redirect(bp, txr, mapping, xdp->len, xdp); 246 nxmit++; 247 } 248 249 if (flags & XDP_XMIT_FLUSH) { 250 /* Sync BD data before updating doorbell */ 251 wmb(); 252 bnxt_db_write(bp, &txr->tx_db, txr->tx_prod); 253 } 254 255 return nxmit; 256 } 257 258 /* Under rtnl_lock */ 259 static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog) 260 { 261 struct net_device *dev = bp->dev; 262 int tx_xdp = 0, rc, tc; 263 struct bpf_prog *old; 264 265 if (prog && bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) { 266 netdev_warn(dev, "MTU %d larger than largest XDP supported MTU %d.\n", 267 bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU); 268 return -EOPNOTSUPP; 269 } 270 if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) { 271 netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n"); 272 return -EOPNOTSUPP; 273 } 274 if (prog) 275 tx_xdp = bp->rx_nr_rings; 276 277 tc = netdev_get_num_tc(dev); 278 if (!tc) 279 tc = 1; 280 rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings, 281 true, tc, tx_xdp); 282 if (rc) { 283 netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n"); 284 return rc; 285 } 286 if (netif_running(dev)) 287 bnxt_close_nic(bp, true, false); 288 289 old = xchg(&bp->xdp_prog, prog); 290 if (old) 291 bpf_prog_put(old); 292 293 if (prog) { 294 bnxt_set_rx_skb_mode(bp, true); 295 } else { 296 int rx, tx; 297 298 bnxt_set_rx_skb_mode(bp, false); 299 bnxt_get_max_rings(bp, &rx, &tx, true); 300 if (rx > 1) { 301 bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS; 302 bp->dev->hw_features |= NETIF_F_LRO; 303 } 304 } 305 bp->tx_nr_rings_xdp = tx_xdp; 306 bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp; 307 bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings); 308 bnxt_set_tpa_flags(bp); 309 bnxt_set_ring_params(bp); 310 311 if (netif_running(dev)) 312 return bnxt_open_nic(bp, true, false); 313 314 return 0; 315 } 316 317 int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp) 318 { 319 struct bnxt *bp = netdev_priv(dev); 320 int rc; 321 322 switch (xdp->command) { 323 case XDP_SETUP_PROG: 324 rc = bnxt_xdp_set(bp, xdp->prog); 325 break; 326 default: 327 rc = -EINVAL; 328 break; 329 } 330 return rc; 331 } 332