1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2019, Intel Corporation. */
3 
4 #include <linux/filter.h>
5 
6 #include "ice_txrx_lib.h"
7 #include "ice_eswitch.h"
8 #include "ice_lib.h"
9 
10 /**
11  * ice_release_rx_desc - Store the new tail and head values
12  * @rx_ring: ring to bump
13  * @val: new head index
14  */
15 void ice_release_rx_desc(struct ice_rx_ring *rx_ring, u16 val)
16 {
17 	u16 prev_ntu = rx_ring->next_to_use & ~0x7;
18 
19 	rx_ring->next_to_use = val;
20 
21 	/* update next to alloc since we have filled the ring */
22 	rx_ring->next_to_alloc = val;
23 
24 	/* QRX_TAIL will be updated with any tail value, but hardware ignores
25 	 * the lower 3 bits. This makes it so we only bump tail on meaningful
26 	 * boundaries. Also, this allows us to bump tail on intervals of 8 up to
27 	 * the budget depending on the current traffic load.
28 	 */
29 	val &= ~0x7;
30 	if (prev_ntu != val) {
31 		/* Force memory writes to complete before letting h/w
32 		 * know there are new descriptors to fetch. (Only
33 		 * applicable for weak-ordered memory model archs,
34 		 * such as IA-64).
35 		 */
36 		wmb();
37 		writel(val, rx_ring->tail);
38 	}
39 }
40 
41 /**
42  * ice_ptype_to_htype - get a hash type
43  * @ptype: the ptype value from the descriptor
44  *
45  * Returns appropriate hash type (such as PKT_HASH_TYPE_L2/L3/L4) to be used by
46  * skb_set_hash based on PTYPE as parsed by HW Rx pipeline and is part of
47  * Rx desc.
48  */
49 static enum pkt_hash_types ice_ptype_to_htype(u16 ptype)
50 {
51 	struct ice_rx_ptype_decoded decoded = ice_decode_rx_desc_ptype(ptype);
52 
53 	if (!decoded.known)
54 		return PKT_HASH_TYPE_NONE;
55 	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY4)
56 		return PKT_HASH_TYPE_L4;
57 	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY3)
58 		return PKT_HASH_TYPE_L3;
59 	if (decoded.outer_ip == ICE_RX_PTYPE_OUTER_L2)
60 		return PKT_HASH_TYPE_L2;
61 
62 	return PKT_HASH_TYPE_NONE;
63 }
64 
65 /**
66  * ice_rx_hash - set the hash value in the skb
67  * @rx_ring: descriptor ring
68  * @rx_desc: specific descriptor
69  * @skb: pointer to current skb
70  * @rx_ptype: the ptype value from the descriptor
71  */
72 static void
73 ice_rx_hash(struct ice_rx_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
74 	    struct sk_buff *skb, u16 rx_ptype)
75 {
76 	struct ice_32b_rx_flex_desc_nic *nic_mdid;
77 	u32 hash;
78 
79 	if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
80 		return;
81 
82 	if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
83 		return;
84 
85 	nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
86 	hash = le32_to_cpu(nic_mdid->rss_hash);
87 	skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
88 }
89 
90 /**
91  * ice_rx_csum - Indicate in skb if checksum is good
92  * @ring: the ring we care about
93  * @skb: skb currently being received and modified
94  * @rx_desc: the receive descriptor
95  * @ptype: the packet type decoded by hardware
96  *
97  * skb->protocol must be set before this function is called
98  */
99 static void
100 ice_rx_csum(struct ice_rx_ring *ring, struct sk_buff *skb,
101 	    union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
102 {
103 	struct ice_rx_ptype_decoded decoded;
104 	u16 rx_status0, rx_status1;
105 	bool ipv4, ipv6;
106 
107 	rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
108 	rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);
109 
110 	decoded = ice_decode_rx_desc_ptype(ptype);
111 
112 	/* Start with CHECKSUM_NONE and by default csum_level = 0 */
113 	skb->ip_summed = CHECKSUM_NONE;
114 	skb_checksum_none_assert(skb);
115 
116 	/* check if Rx checksum is enabled */
117 	if (!(ring->netdev->features & NETIF_F_RXCSUM))
118 		return;
119 
120 	/* check if HW has decoded the packet and checksum */
121 	if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
122 		return;
123 
124 	if (!(decoded.known && decoded.outer_ip))
125 		return;
126 
127 	ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
128 	       (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
129 	ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
130 	       (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);
131 
132 	if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
133 				   BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
134 		goto checksum_fail;
135 
136 	if (ipv6 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
137 		goto checksum_fail;
138 
139 	/* check for L4 errors and handle packets that were not able to be
140 	 * checksummed due to arrival speed
141 	 */
142 	if (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
143 		goto checksum_fail;
144 
145 	/* check for outer UDP checksum error in tunneled packets */
146 	if ((rx_status1 & BIT(ICE_RX_FLEX_DESC_STATUS1_NAT_S)) &&
147 	    (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S)))
148 		goto checksum_fail;
149 
150 	/* If there is an outer header present that might contain a checksum
151 	 * we need to bump the checksum level by 1 to reflect the fact that
152 	 * we are indicating we validated the inner checksum.
153 	 */
154 	if (decoded.tunnel_type >= ICE_RX_PTYPE_TUNNEL_IP_GRENAT)
155 		skb->csum_level = 1;
156 
157 	/* Only report checksum unnecessary for TCP, UDP, or SCTP */
158 	switch (decoded.inner_prot) {
159 	case ICE_RX_PTYPE_INNER_PROT_TCP:
160 	case ICE_RX_PTYPE_INNER_PROT_UDP:
161 	case ICE_RX_PTYPE_INNER_PROT_SCTP:
162 		skb->ip_summed = CHECKSUM_UNNECESSARY;
163 		break;
164 	default:
165 		break;
166 	}
167 	return;
168 
169 checksum_fail:
170 	ring->vsi->back->hw_csum_rx_error++;
171 }
172 
173 /**
174  * ice_process_skb_fields - Populate skb header fields from Rx descriptor
175  * @rx_ring: Rx descriptor ring packet is being transacted on
176  * @rx_desc: pointer to the EOP Rx descriptor
177  * @skb: pointer to current skb being populated
178  * @ptype: the packet type decoded by hardware
179  *
180  * This function checks the ring, descriptor, and packet information in
181  * order to populate the hash, checksum, VLAN, protocol, and
182  * other fields within the skb.
183  */
184 void
185 ice_process_skb_fields(struct ice_rx_ring *rx_ring,
186 		       union ice_32b_rx_flex_desc *rx_desc,
187 		       struct sk_buff *skb, u16 ptype)
188 {
189 	ice_rx_hash(rx_ring, rx_desc, skb, ptype);
190 
191 	/* modifies the skb - consumes the enet header */
192 	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
193 
194 	ice_rx_csum(rx_ring, skb, rx_desc, ptype);
195 
196 	if (rx_ring->ptp_rx)
197 		ice_ptp_rx_hwtstamp(rx_ring, rx_desc, skb);
198 }
199 
200 /**
201  * ice_receive_skb - Send a completed packet up the stack
202  * @rx_ring: Rx ring in play
203  * @skb: packet to send up
204  * @vlan_tag: VLAN tag for packet
205  *
206  * This function sends the completed packet (via. skb) up the stack using
207  * gro receive functions (with/without VLAN tag)
208  */
209 void
210 ice_receive_skb(struct ice_rx_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
211 {
212 	netdev_features_t features = rx_ring->netdev->features;
213 	bool non_zero_vlan = !!(vlan_tag & VLAN_VID_MASK);
214 
215 	if ((features & NETIF_F_HW_VLAN_CTAG_RX) && non_zero_vlan)
216 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
217 	else if ((features & NETIF_F_HW_VLAN_STAG_RX) && non_zero_vlan)
218 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021AD), vlan_tag);
219 
220 	napi_gro_receive(&rx_ring->q_vector->napi, skb);
221 }
222 
223 /**
224  * ice_clean_xdp_tx_buf - Free and unmap XDP Tx buffer
225  * @dev: device for DMA mapping
226  * @tx_buf: Tx buffer to clean
227  * @bq: XDP bulk flush struct
228  */
229 static void
230 ice_clean_xdp_tx_buf(struct device *dev, struct ice_tx_buf *tx_buf,
231 		     struct xdp_frame_bulk *bq)
232 {
233 	dma_unmap_single(dev, dma_unmap_addr(tx_buf, dma),
234 			 dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);
235 	dma_unmap_len_set(tx_buf, len, 0);
236 
237 	switch (tx_buf->type) {
238 	case ICE_TX_BUF_XDP_TX:
239 		page_frag_free(tx_buf->raw_buf);
240 		break;
241 	case ICE_TX_BUF_XDP_XMIT:
242 		xdp_return_frame_bulk(tx_buf->xdpf, bq);
243 		break;
244 	}
245 
246 	tx_buf->type = ICE_TX_BUF_EMPTY;
247 }
248 
249 /**
250  * ice_clean_xdp_irq - Reclaim resources after transmit completes on XDP ring
251  * @xdp_ring: XDP ring to clean
252  */
253 static u32 ice_clean_xdp_irq(struct ice_tx_ring *xdp_ring)
254 {
255 	int total_bytes = 0, total_pkts = 0;
256 	struct device *dev = xdp_ring->dev;
257 	u32 ntc = xdp_ring->next_to_clean;
258 	struct ice_tx_desc *tx_desc;
259 	u32 cnt = xdp_ring->count;
260 	struct xdp_frame_bulk bq;
261 	u32 frags, xdp_tx = 0;
262 	u32 ready_frames = 0;
263 	u32 idx;
264 	u32 ret;
265 
266 	idx = xdp_ring->tx_buf[ntc].rs_idx;
267 	tx_desc = ICE_TX_DESC(xdp_ring, idx);
268 	if (tx_desc->cmd_type_offset_bsz &
269 	    cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE)) {
270 		if (idx >= ntc)
271 			ready_frames = idx - ntc + 1;
272 		else
273 			ready_frames = idx + cnt - ntc + 1;
274 	}
275 
276 	if (unlikely(!ready_frames))
277 		return 0;
278 	ret = ready_frames;
279 
280 	xdp_frame_bulk_init(&bq);
281 	rcu_read_lock(); /* xdp_return_frame_bulk() */
282 
283 	while (ready_frames) {
284 		struct ice_tx_buf *tx_buf = &xdp_ring->tx_buf[ntc];
285 		struct ice_tx_buf *head = tx_buf;
286 
287 		/* bytecount holds size of head + frags */
288 		total_bytes += tx_buf->bytecount;
289 		frags = tx_buf->nr_frags;
290 		total_pkts++;
291 		/* count head + frags */
292 		ready_frames -= frags + 1;
293 		xdp_tx++;
294 
295 		ntc++;
296 		if (ntc == cnt)
297 			ntc = 0;
298 
299 		for (int i = 0; i < frags; i++) {
300 			tx_buf = &xdp_ring->tx_buf[ntc];
301 
302 			ice_clean_xdp_tx_buf(dev, tx_buf, &bq);
303 			ntc++;
304 			if (ntc == cnt)
305 				ntc = 0;
306 		}
307 
308 		ice_clean_xdp_tx_buf(dev, head, &bq);
309 	}
310 
311 	xdp_flush_frame_bulk(&bq);
312 	rcu_read_unlock();
313 
314 	tx_desc->cmd_type_offset_bsz = 0;
315 	xdp_ring->next_to_clean = ntc;
316 	xdp_ring->xdp_tx_active -= xdp_tx;
317 	ice_update_tx_ring_stats(xdp_ring, total_pkts, total_bytes);
318 
319 	return ret;
320 }
321 
322 /**
323  * __ice_xmit_xdp_ring - submit frame to XDP ring for transmission
324  * @xdp: XDP buffer to be placed onto Tx descriptors
325  * @xdp_ring: XDP ring for transmission
326  * @frame: whether this comes from .ndo_xdp_xmit()
327  */
328 int __ice_xmit_xdp_ring(struct xdp_buff *xdp, struct ice_tx_ring *xdp_ring,
329 			bool frame)
330 {
331 	struct skb_shared_info *sinfo = NULL;
332 	u32 size = xdp->data_end - xdp->data;
333 	struct device *dev = xdp_ring->dev;
334 	u32 ntu = xdp_ring->next_to_use;
335 	struct ice_tx_desc *tx_desc;
336 	struct ice_tx_buf *tx_head;
337 	struct ice_tx_buf *tx_buf;
338 	u32 cnt = xdp_ring->count;
339 	void *data = xdp->data;
340 	u32 nr_frags = 0;
341 	u32 free_space;
342 	u32 frag = 0;
343 
344 	free_space = ICE_DESC_UNUSED(xdp_ring);
345 	if (free_space < ICE_RING_QUARTER(xdp_ring))
346 		free_space += ice_clean_xdp_irq(xdp_ring);
347 
348 	if (unlikely(!free_space))
349 		goto busy;
350 
351 	if (unlikely(xdp_buff_has_frags(xdp))) {
352 		sinfo = xdp_get_shared_info_from_buff(xdp);
353 		nr_frags = sinfo->nr_frags;
354 		if (free_space < nr_frags + 1)
355 			goto busy;
356 	}
357 
358 	tx_desc = ICE_TX_DESC(xdp_ring, ntu);
359 	tx_head = &xdp_ring->tx_buf[ntu];
360 	tx_buf = tx_head;
361 
362 	for (;;) {
363 		dma_addr_t dma;
364 
365 		dma = dma_map_single(dev, data, size, DMA_TO_DEVICE);
366 		if (dma_mapping_error(dev, dma))
367 			goto dma_unmap;
368 
369 		/* record length, and DMA address */
370 		dma_unmap_len_set(tx_buf, len, size);
371 		dma_unmap_addr_set(tx_buf, dma, dma);
372 
373 		if (frame) {
374 			tx_buf->type = ICE_TX_BUF_FRAG;
375 		} else {
376 			tx_buf->type = ICE_TX_BUF_XDP_TX;
377 			tx_buf->raw_buf = data;
378 		}
379 
380 		tx_desc->buf_addr = cpu_to_le64(dma);
381 		tx_desc->cmd_type_offset_bsz = ice_build_ctob(0, 0, size, 0);
382 
383 		ntu++;
384 		if (ntu == cnt)
385 			ntu = 0;
386 
387 		if (frag == nr_frags)
388 			break;
389 
390 		tx_desc = ICE_TX_DESC(xdp_ring, ntu);
391 		tx_buf = &xdp_ring->tx_buf[ntu];
392 
393 		data = skb_frag_address(&sinfo->frags[frag]);
394 		size = skb_frag_size(&sinfo->frags[frag]);
395 		frag++;
396 	}
397 
398 	/* store info about bytecount and frag count in first desc */
399 	tx_head->bytecount = xdp_get_buff_len(xdp);
400 	tx_head->nr_frags = nr_frags;
401 
402 	if (frame) {
403 		tx_head->type = ICE_TX_BUF_XDP_XMIT;
404 		tx_head->xdpf = xdp->data_hard_start;
405 	}
406 
407 	/* update last descriptor from a frame with EOP */
408 	tx_desc->cmd_type_offset_bsz |=
409 		cpu_to_le64(ICE_TX_DESC_CMD_EOP << ICE_TXD_QW1_CMD_S);
410 
411 	xdp_ring->xdp_tx_active++;
412 	xdp_ring->next_to_use = ntu;
413 
414 	return ICE_XDP_TX;
415 
416 dma_unmap:
417 	for (;;) {
418 		tx_buf = &xdp_ring->tx_buf[ntu];
419 		dma_unmap_page(dev, dma_unmap_addr(tx_buf, dma),
420 			       dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);
421 		dma_unmap_len_set(tx_buf, len, 0);
422 		if (tx_buf == tx_head)
423 			break;
424 
425 		if (!ntu)
426 			ntu += cnt;
427 		ntu--;
428 	}
429 	return ICE_XDP_CONSUMED;
430 
431 busy:
432 	xdp_ring->ring_stats->tx_stats.tx_busy++;
433 
434 	return ICE_XDP_CONSUMED;
435 }
436 
437 /**
438  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
439  * @xdp_ring: XDP ring
440  * @xdp_res: Result of the receive batch
441  *
442  * This function bumps XDP Tx tail and/or flush redirect map, and
443  * should be called when a batch of packets has been processed in the
444  * napi loop.
445  */
446 void ice_finalize_xdp_rx(struct ice_tx_ring *xdp_ring, unsigned int xdp_res,
447 			 u32 first_idx)
448 {
449 	struct ice_tx_buf *tx_buf = &xdp_ring->tx_buf[first_idx];
450 
451 	if (xdp_res & ICE_XDP_REDIR)
452 		xdp_do_flush_map();
453 
454 	if (xdp_res & ICE_XDP_TX) {
455 		if (static_branch_unlikely(&ice_xdp_locking_key))
456 			spin_lock(&xdp_ring->tx_lock);
457 		/* store index of descriptor with RS bit set in the first
458 		 * ice_tx_buf of given NAPI batch
459 		 */
460 		tx_buf->rs_idx = ice_set_rs_bit(xdp_ring);
461 		ice_xdp_ring_update_tail(xdp_ring);
462 		if (static_branch_unlikely(&ice_xdp_locking_key))
463 			spin_unlock(&xdp_ring->tx_lock);
464 	}
465 }
466