1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2019, Intel Corporation. */
3 
4 #include "ice_txrx_lib.h"
5 
6 /**
7  * ice_release_rx_desc - Store the new tail and head values
8  * @rx_ring: ring to bump
9  * @val: new head index
10  */
11 void ice_release_rx_desc(struct ice_ring *rx_ring, u16 val)
12 {
13 	u16 prev_ntu = rx_ring->next_to_use & ~0x7;
14 
15 	rx_ring->next_to_use = val;
16 
17 	/* update next to alloc since we have filled the ring */
18 	rx_ring->next_to_alloc = val;
19 
20 	/* QRX_TAIL will be updated with any tail value, but hardware ignores
21 	 * the lower 3 bits. This makes it so we only bump tail on meaningful
22 	 * boundaries. Also, this allows us to bump tail on intervals of 8 up to
23 	 * the budget depending on the current traffic load.
24 	 */
25 	val &= ~0x7;
26 	if (prev_ntu != val) {
27 		/* Force memory writes to complete before letting h/w
28 		 * know there are new descriptors to fetch. (Only
29 		 * applicable for weak-ordered memory model archs,
30 		 * such as IA-64).
31 		 */
32 		wmb();
33 		writel(val, rx_ring->tail);
34 	}
35 }
36 
37 /**
38  * ice_ptype_to_htype - get a hash type
39  * @ptype: the ptype value from the descriptor
40  *
41  * Returns appropriate hash type (such as PKT_HASH_TYPE_L2/L3/L4) to be used by
42  * skb_set_hash based on PTYPE as parsed by HW Rx pipeline and is part of
43  * Rx desc.
44  */
45 static enum pkt_hash_types ice_ptype_to_htype(u16 ptype)
46 {
47 	struct ice_rx_ptype_decoded decoded = ice_decode_rx_desc_ptype(ptype);
48 
49 	if (!decoded.known)
50 		return PKT_HASH_TYPE_NONE;
51 	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY4)
52 		return PKT_HASH_TYPE_L4;
53 	if (decoded.payload_layer == ICE_RX_PTYPE_PAYLOAD_LAYER_PAY3)
54 		return PKT_HASH_TYPE_L3;
55 	if (decoded.outer_ip == ICE_RX_PTYPE_OUTER_L2)
56 		return PKT_HASH_TYPE_L2;
57 
58 	return PKT_HASH_TYPE_NONE;
59 }
60 
61 /**
62  * ice_rx_hash - set the hash value in the skb
63  * @rx_ring: descriptor ring
64  * @rx_desc: specific descriptor
65  * @skb: pointer to current skb
66  * @rx_ptype: the ptype value from the descriptor
67  */
68 static void
69 ice_rx_hash(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
70 	    struct sk_buff *skb, u16 rx_ptype)
71 {
72 	struct ice_32b_rx_flex_desc_nic *nic_mdid;
73 	u32 hash;
74 
75 	if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
76 		return;
77 
78 	if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
79 		return;
80 
81 	nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
82 	hash = le32_to_cpu(nic_mdid->rss_hash);
83 	skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
84 }
85 
86 /**
87  * ice_rx_csum - Indicate in skb if checksum is good
88  * @ring: the ring we care about
89  * @skb: skb currently being received and modified
90  * @rx_desc: the receive descriptor
91  * @ptype: the packet type decoded by hardware
92  *
93  * skb->protocol must be set before this function is called
94  */
95 static void
96 ice_rx_csum(struct ice_ring *ring, struct sk_buff *skb,
97 	    union ice_32b_rx_flex_desc *rx_desc, u16 ptype)
98 {
99 	struct ice_rx_ptype_decoded decoded;
100 	u16 rx_status0, rx_status1;
101 	bool ipv4, ipv6;
102 
103 	rx_status0 = le16_to_cpu(rx_desc->wb.status_error0);
104 	rx_status1 = le16_to_cpu(rx_desc->wb.status_error1);
105 
106 	decoded = ice_decode_rx_desc_ptype(ptype);
107 
108 	/* Start with CHECKSUM_NONE and by default csum_level = 0 */
109 	skb->ip_summed = CHECKSUM_NONE;
110 	skb_checksum_none_assert(skb);
111 
112 	/* check if Rx checksum is enabled */
113 	if (!(ring->netdev->features & NETIF_F_RXCSUM))
114 		return;
115 
116 	/* check if HW has decoded the packet and checksum */
117 	if (!(rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
118 		return;
119 
120 	if (!(decoded.known && decoded.outer_ip))
121 		return;
122 
123 	ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
124 	       (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
125 	ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
126 	       (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);
127 
128 	if (ipv4 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
129 				   BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
130 		goto checksum_fail;
131 
132 	if (ipv6 && (rx_status0 & (BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
133 		goto checksum_fail;
134 
135 	/* check for L4 errors and handle packets that were not able to be
136 	 * checksummed due to arrival speed
137 	 */
138 	if (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
139 		goto checksum_fail;
140 
141 	/* check for outer UDP checksum error in tunneled packets */
142 	if ((rx_status1 & BIT(ICE_RX_FLEX_DESC_STATUS1_NAT_S)) &&
143 	    (rx_status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S)))
144 		goto checksum_fail;
145 
146 	/* If there is an outer header present that might contain a checksum
147 	 * we need to bump the checksum level by 1 to reflect the fact that
148 	 * we are indicating we validated the inner checksum.
149 	 */
150 	if (decoded.tunnel_type >= ICE_RX_PTYPE_TUNNEL_IP_GRENAT)
151 		skb->csum_level = 1;
152 
153 	/* Only report checksum unnecessary for TCP, UDP, or SCTP */
154 	switch (decoded.inner_prot) {
155 	case ICE_RX_PTYPE_INNER_PROT_TCP:
156 	case ICE_RX_PTYPE_INNER_PROT_UDP:
157 	case ICE_RX_PTYPE_INNER_PROT_SCTP:
158 		skb->ip_summed = CHECKSUM_UNNECESSARY;
159 		break;
160 	default:
161 		break;
162 	}
163 	return;
164 
165 checksum_fail:
166 	ring->vsi->back->hw_csum_rx_error++;
167 }
168 
169 /**
170  * ice_process_skb_fields - Populate skb header fields from Rx descriptor
171  * @rx_ring: Rx descriptor ring packet is being transacted on
172  * @rx_desc: pointer to the EOP Rx descriptor
173  * @skb: pointer to current skb being populated
174  * @ptype: the packet type decoded by hardware
175  *
176  * This function checks the ring, descriptor, and packet information in
177  * order to populate the hash, checksum, VLAN, protocol, and
178  * other fields within the skb.
179  */
180 void
181 ice_process_skb_fields(struct ice_ring *rx_ring,
182 		       union ice_32b_rx_flex_desc *rx_desc,
183 		       struct sk_buff *skb, u16 ptype)
184 {
185 	ice_rx_hash(rx_ring, rx_desc, skb, ptype);
186 
187 	/* modifies the skb - consumes the enet header */
188 	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
189 
190 	ice_rx_csum(rx_ring, skb, rx_desc, ptype);
191 
192 	if (rx_ring->ptp_rx)
193 		ice_ptp_rx_hwtstamp(rx_ring, rx_desc, skb);
194 }
195 
196 /**
197  * ice_receive_skb - Send a completed packet up the stack
198  * @rx_ring: Rx ring in play
199  * @skb: packet to send up
200  * @vlan_tag: VLAN tag for packet
201  *
202  * This function sends the completed packet (via. skb) up the stack using
203  * gro receive functions (with/without VLAN tag)
204  */
205 void
206 ice_receive_skb(struct ice_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
207 {
208 	if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
209 	    (vlan_tag & VLAN_VID_MASK))
210 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
211 	napi_gro_receive(&rx_ring->q_vector->napi, skb);
212 }
213 
214 /**
215  * ice_xmit_xdp_ring - submit single packet to XDP ring for transmission
216  * @data: packet data pointer
217  * @size: packet data size
218  * @xdp_ring: XDP ring for transmission
219  */
220 int ice_xmit_xdp_ring(void *data, u16 size, struct ice_ring *xdp_ring)
221 {
222 	u16 i = xdp_ring->next_to_use;
223 	struct ice_tx_desc *tx_desc;
224 	struct ice_tx_buf *tx_buf;
225 	dma_addr_t dma;
226 
227 	if (!unlikely(ICE_DESC_UNUSED(xdp_ring))) {
228 		xdp_ring->tx_stats.tx_busy++;
229 		return ICE_XDP_CONSUMED;
230 	}
231 
232 	dma = dma_map_single(xdp_ring->dev, data, size, DMA_TO_DEVICE);
233 	if (dma_mapping_error(xdp_ring->dev, dma))
234 		return ICE_XDP_CONSUMED;
235 
236 	tx_buf = &xdp_ring->tx_buf[i];
237 	tx_buf->bytecount = size;
238 	tx_buf->gso_segs = 1;
239 	tx_buf->raw_buf = data;
240 
241 	/* record length, and DMA address */
242 	dma_unmap_len_set(tx_buf, len, size);
243 	dma_unmap_addr_set(tx_buf, dma, dma);
244 
245 	tx_desc = ICE_TX_DESC(xdp_ring, i);
246 	tx_desc->buf_addr = cpu_to_le64(dma);
247 	tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TXD_LAST_DESC_CMD, 0,
248 						      size, 0);
249 
250 	/* Make certain all of the status bits have been updated
251 	 * before next_to_watch is written.
252 	 */
253 	smp_wmb();
254 
255 	i++;
256 	if (i == xdp_ring->count)
257 		i = 0;
258 
259 	tx_buf->next_to_watch = tx_desc;
260 	xdp_ring->next_to_use = i;
261 
262 	return ICE_XDP_TX;
263 }
264 
265 /**
266  * ice_xmit_xdp_buff - convert an XDP buffer to an XDP frame and send it
267  * @xdp: XDP buffer
268  * @xdp_ring: XDP Tx ring
269  *
270  * Returns negative on failure, 0 on success.
271  */
272 int ice_xmit_xdp_buff(struct xdp_buff *xdp, struct ice_ring *xdp_ring)
273 {
274 	struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);
275 
276 	if (unlikely(!xdpf))
277 		return ICE_XDP_CONSUMED;
278 
279 	return ice_xmit_xdp_ring(xdpf->data, xdpf->len, xdp_ring);
280 }
281 
282 /**
283  * ice_finalize_xdp_rx - Bump XDP Tx tail and/or flush redirect map
284  * @rx_ring: Rx ring
285  * @xdp_res: Result of the receive batch
286  *
287  * This function bumps XDP Tx tail and/or flush redirect map, and
288  * should be called when a batch of packets has been processed in the
289  * napi loop.
290  */
291 void ice_finalize_xdp_rx(struct ice_ring *rx_ring, unsigned int xdp_res)
292 {
293 	if (xdp_res & ICE_XDP_REDIR)
294 		xdp_do_flush_map();
295 
296 	if (xdp_res & ICE_XDP_TX) {
297 		struct ice_ring *xdp_ring =
298 			rx_ring->vsi->xdp_rings[rx_ring->q_index];
299 
300 		ice_xdp_ring_update_tail(xdp_ring);
301 	}
302 }
303