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v6.8
  1// SPDX-License-Identifier: GPL-2.0-only
  2/****************************************************************************
  3 * Driver for Solarflare network controllers and boards
  4 * Copyright 2005-2006 Fen Systems Ltd.
  5 * Copyright 2005-2013 Solarflare Communications Inc.
 
 
 
 
  6 */
  7
  8#include <linux/socket.h>
  9#include <linux/in.h>
 10#include <linux/slab.h>
 11#include <linux/ip.h>
 12#include <linux/ipv6.h>
 13#include <linux/tcp.h>
 14#include <linux/udp.h>
 15#include <linux/prefetch.h>
 16#include <linux/moduleparam.h>
 17#include <linux/iommu.h>
 18#include <net/ip.h>
 19#include <net/checksum.h>
 20#include <net/xdp.h>
 21#include <linux/bpf_trace.h>
 22#include "net_driver.h"
 23#include "efx.h"
 24#include "rx_common.h"
 25#include "filter.h"
 26#include "nic.h"
 27#include "selftest.h"
 28#include "workarounds.h"
 29
 30/* Preferred number of descriptors to fill at once */
 31#define EFX_RX_PREFERRED_BATCH 8U
 32
 33/* Maximum rx prefix used by any architecture. */
 34#define EFX_MAX_RX_PREFIX_SIZE 16
 
 
 
 
 35
 36/* Size of buffer allocated for skb header area. */
 37#define EFX_SKB_HEADERS  128u
 38
 
 
 
 
 
 39/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
 40#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
 41				      EFX_RX_USR_BUF_SIZE)
 42
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 43static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
 44				     struct efx_rx_buffer *rx_buf,
 45				     int len)
 46{
 47	struct efx_nic *efx = rx_queue->efx;
 48	unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
 49
 50	if (likely(len <= max_len))
 51		return;
 52
 53	/* The packet must be discarded, but this is only a fatal error
 54	 * if the caller indicated it was
 55	 */
 56	rx_buf->flags |= EFX_RX_PKT_DISCARD;
 57
 58	if (net_ratelimit())
 59		netif_err(efx, rx_err, efx->net_dev,
 60			  "RX queue %d overlength RX event (%#x > %#x)\n",
 61			  efx_rx_queue_index(rx_queue), len, max_len);
 
 
 
 
 
 
 
 
 
 
 
 62
 63	efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
 64}
 65
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 66/* Allocate and construct an SKB around page fragments */
 67static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
 68				     struct efx_rx_buffer *rx_buf,
 69				     unsigned int n_frags,
 70				     u8 *eh, int hdr_len)
 71{
 72	struct efx_nic *efx = channel->efx;
 73	struct sk_buff *skb;
 74
 75	/* Allocate an SKB to store the headers */
 76	skb = netdev_alloc_skb(efx->net_dev,
 77			       efx->rx_ip_align + efx->rx_prefix_size +
 78			       hdr_len);
 79	if (unlikely(skb == NULL)) {
 80		atomic_inc(&efx->n_rx_noskb_drops);
 81		return NULL;
 82	}
 83
 84	EFX_WARN_ON_ONCE_PARANOID(rx_buf->len < hdr_len);
 85
 86	memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
 87	       efx->rx_prefix_size + hdr_len);
 88	skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
 89	__skb_put(skb, hdr_len);
 90
 91	/* Append the remaining page(s) onto the frag list */
 92	if (rx_buf->len > hdr_len) {
 93		rx_buf->page_offset += hdr_len;
 94		rx_buf->len -= hdr_len;
 95
 96		for (;;) {
 97			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 98					rx_buf->page, rx_buf->page_offset,
 99					rx_buf->len, efx->rx_buffer_truesize);
100			rx_buf->page = NULL;
101
 
102			if (skb_shinfo(skb)->nr_frags == n_frags)
103				break;
104
105			rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
106		}
107	} else {
108		__free_pages(rx_buf->page, efx->rx_buffer_order);
109		rx_buf->page = NULL;
110		n_frags = 0;
111	}
112
 
 
113	/* Move past the ethernet header */
114	skb->protocol = eth_type_trans(skb, efx->net_dev);
115
116	skb_mark_napi_id(skb, &channel->napi_str);
117
118	return skb;
119}
120
121void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
122		   unsigned int n_frags, unsigned int len, u16 flags)
123{
124	struct efx_nic *efx = rx_queue->efx;
125	struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
126	struct efx_rx_buffer *rx_buf;
127
128	rx_queue->rx_packets++;
129
130	rx_buf = efx_rx_buffer(rx_queue, index);
131	rx_buf->flags |= flags;
132
133	/* Validate the number of fragments and completed length */
134	if (n_frags == 1) {
135		if (!(flags & EFX_RX_PKT_PREFIX_LEN))
136			efx_rx_packet__check_len(rx_queue, rx_buf, len);
137	} else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
138		   unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
139		   unlikely(len > n_frags * efx->rx_dma_len) ||
140		   unlikely(!efx->rx_scatter)) {
141		/* If this isn't an explicit discard request, either
142		 * the hardware or the driver is broken.
143		 */
144		WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
145		rx_buf->flags |= EFX_RX_PKT_DISCARD;
146	}
147
148	netif_vdbg(efx, rx_status, efx->net_dev,
149		   "RX queue %d received ids %x-%x len %d %s%s\n",
150		   efx_rx_queue_index(rx_queue), index,
151		   (index + n_frags - 1) & rx_queue->ptr_mask, len,
152		   (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
153		   (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
154
155	/* Discard packet, if instructed to do so.  Process the
156	 * previous receive first.
157	 */
158	if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
159		efx_rx_flush_packet(channel);
160		efx_discard_rx_packet(channel, rx_buf, n_frags);
161		return;
162	}
163
164	if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))
165		rx_buf->len = len;
166
167	/* Release and/or sync the DMA mapping - assumes all RX buffers
168	 * consumed in-order per RX queue.
169	 */
170	efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
171
172	/* Prefetch nice and early so data will (hopefully) be in cache by
173	 * the time we look at it.
174	 */
175	prefetch(efx_rx_buf_va(rx_buf));
176
177	rx_buf->page_offset += efx->rx_prefix_size;
178	rx_buf->len -= efx->rx_prefix_size;
179
180	if (n_frags > 1) {
181		/* Release/sync DMA mapping for additional fragments.
182		 * Fix length for last fragment.
183		 */
184		unsigned int tail_frags = n_frags - 1;
185
186		for (;;) {
187			rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
188			if (--tail_frags == 0)
189				break;
190			efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
191		}
192		rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
193		efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
194	}
195
196	/* All fragments have been DMA-synced, so recycle pages. */
197	rx_buf = efx_rx_buffer(rx_queue, index);
198	efx_recycle_rx_pages(channel, rx_buf, n_frags);
199
200	/* Pipeline receives so that we give time for packet headers to be
201	 * prefetched into cache.
202	 */
203	efx_rx_flush_packet(channel);
204	channel->rx_pkt_n_frags = n_frags;
205	channel->rx_pkt_index = index;
206}
207
208static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
209			   struct efx_rx_buffer *rx_buf,
210			   unsigned int n_frags)
211{
212	struct sk_buff *skb;
213	u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
214
215	skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
216	if (unlikely(skb == NULL)) {
217		struct efx_rx_queue *rx_queue;
218
219		rx_queue = efx_channel_get_rx_queue(channel);
220		efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
221		return;
222	}
223	skb_record_rx_queue(skb, channel->rx_queue.core_index);
224
225	/* Set the SKB flags */
226	skb_checksum_none_assert(skb);
227	if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED)) {
228		skb->ip_summed = CHECKSUM_UNNECESSARY;
229		skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
230	}
231
232	efx_rx_skb_attach_timestamp(channel, skb);
233
234	if (channel->type->receive_skb)
235		if (channel->type->receive_skb(channel, skb))
236			return;
237
238	/* Pass the packet up */
239	if (channel->rx_list != NULL)
240		/* Add to list, will pass up later */
241		list_add_tail(&skb->list, channel->rx_list);
242	else
243		/* No list, so pass it up now */
244		netif_receive_skb(skb);
245}
246
247/** efx_do_xdp: perform XDP processing on a received packet
248 *
249 * Returns true if packet should still be delivered.
250 */
251static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
252		       struct efx_rx_buffer *rx_buf, u8 **ehp)
253{
254	u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE];
255	struct efx_rx_queue *rx_queue;
256	struct bpf_prog *xdp_prog;
257	struct xdp_frame *xdpf;
258	struct xdp_buff xdp;
259	u32 xdp_act;
260	s16 offset;
261	int err;
262
263	xdp_prog = rcu_dereference_bh(efx->xdp_prog);
264	if (!xdp_prog)
265		return true;
266
267	rx_queue = efx_channel_get_rx_queue(channel);
268
269	if (unlikely(channel->rx_pkt_n_frags > 1)) {
270		/* We can't do XDP on fragmented packets - drop. */
271		efx_free_rx_buffers(rx_queue, rx_buf,
272				    channel->rx_pkt_n_frags);
273		if (net_ratelimit())
274			netif_err(efx, rx_err, efx->net_dev,
275				  "XDP is not possible with multiple receive fragments (%d)\n",
276				  channel->rx_pkt_n_frags);
277		channel->n_rx_xdp_bad_drops++;
278		return false;
279	}
280
281	dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr,
282				rx_buf->len, DMA_FROM_DEVICE);
283
284	/* Save the rx prefix. */
285	EFX_WARN_ON_PARANOID(efx->rx_prefix_size > EFX_MAX_RX_PREFIX_SIZE);
286	memcpy(rx_prefix, *ehp - efx->rx_prefix_size,
287	       efx->rx_prefix_size);
288
289	xdp_init_buff(&xdp, efx->rx_page_buf_step, &rx_queue->xdp_rxq_info);
290	/* No support yet for XDP metadata */
291	xdp_prepare_buff(&xdp, *ehp - EFX_XDP_HEADROOM, EFX_XDP_HEADROOM,
292			 rx_buf->len, false);
293
294	xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp);
295
296	offset = (u8 *)xdp.data - *ehp;
297
298	switch (xdp_act) {
299	case XDP_PASS:
300		/* Fix up rx prefix. */
301		if (offset) {
302			*ehp += offset;
303			rx_buf->page_offset += offset;
304			rx_buf->len -= offset;
305			memcpy(*ehp - efx->rx_prefix_size, rx_prefix,
306			       efx->rx_prefix_size);
307		}
308		break;
309
310	case XDP_TX:
311		/* Buffer ownership passes to tx on success. */
312		xdpf = xdp_convert_buff_to_frame(&xdp);
313		err = efx_xdp_tx_buffers(efx, 1, &xdpf, true);
314		if (unlikely(err != 1)) {
315			efx_free_rx_buffers(rx_queue, rx_buf, 1);
316			if (net_ratelimit())
317				netif_err(efx, rx_err, efx->net_dev,
318					  "XDP TX failed (%d)\n", err);
319			channel->n_rx_xdp_bad_drops++;
320			trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
321		} else {
322			channel->n_rx_xdp_tx++;
323		}
324		break;
325
326	case XDP_REDIRECT:
327		err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog);
328		if (unlikely(err)) {
329			efx_free_rx_buffers(rx_queue, rx_buf, 1);
330			if (net_ratelimit())
331				netif_err(efx, rx_err, efx->net_dev,
332					  "XDP redirect failed (%d)\n", err);
333			channel->n_rx_xdp_bad_drops++;
334			trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
335		} else {
336			channel->n_rx_xdp_redirect++;
337		}
338		break;
339
340	default:
341		bpf_warn_invalid_xdp_action(efx->net_dev, xdp_prog, xdp_act);
342		efx_free_rx_buffers(rx_queue, rx_buf, 1);
343		channel->n_rx_xdp_bad_drops++;
344		trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
345		break;
346
347	case XDP_ABORTED:
348		trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
349		fallthrough;
350	case XDP_DROP:
351		efx_free_rx_buffers(rx_queue, rx_buf, 1);
352		channel->n_rx_xdp_drops++;
353		break;
354	}
355
356	return xdp_act == XDP_PASS;
357}
358
359/* Handle a received packet.  Second half: Touches packet payload. */
360void __efx_rx_packet(struct efx_channel *channel)
361{
362	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
363	struct efx_nic *efx = channel->efx;
364	struct efx_rx_buffer *rx_buf =
365		efx_rx_buffer(rx_queue, channel->rx_pkt_index);
366	u8 *eh = efx_rx_buf_va(rx_buf);
367
368	/* Read length from the prefix if necessary.  This already
369	 * excludes the length of the prefix itself.
370	 */
371	if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN) {
372		rx_buf->len = le16_to_cpup((__le16 *)
373					   (eh + efx->rx_packet_len_offset));
374		/* A known issue may prevent this being filled in;
375		 * if that happens, just drop the packet.
376		 * Must do that in the driver since passing a zero-length
377		 * packet up to the stack may cause a crash.
378		 */
379		if (unlikely(!rx_buf->len)) {
380			efx_free_rx_buffers(rx_queue, rx_buf,
381					    channel->rx_pkt_n_frags);
382			channel->n_rx_frm_trunc++;
383			goto out;
384		}
385	}
386
387	/* If we're in loopback test, then pass the packet directly to the
388	 * loopback layer, and free the rx_buf here
389	 */
390	if (unlikely(efx->loopback_selftest)) {
391		efx_loopback_rx_packet(efx, eh, rx_buf->len);
392		efx_free_rx_buffers(rx_queue, rx_buf,
393				    channel->rx_pkt_n_frags);
394		goto out;
395	}
396
397	if (!efx_do_xdp(efx, channel, rx_buf, &eh))
398		goto out;
399
400	if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
401		rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
402
403	if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)
404		efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh, 0);
405	else
406		efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
407out:
408	channel->rx_pkt_n_frags = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
409}
v3.15
 
  1/****************************************************************************
  2 * Driver for Solarflare network controllers and boards
  3 * Copyright 2005-2006 Fen Systems Ltd.
  4 * Copyright 2005-2013 Solarflare Communications Inc.
  5 *
  6 * This program is free software; you can redistribute it and/or modify it
  7 * under the terms of the GNU General Public License version 2 as published
  8 * by the Free Software Foundation, incorporated herein by reference.
  9 */
 10
 11#include <linux/socket.h>
 12#include <linux/in.h>
 13#include <linux/slab.h>
 14#include <linux/ip.h>
 15#include <linux/ipv6.h>
 16#include <linux/tcp.h>
 17#include <linux/udp.h>
 18#include <linux/prefetch.h>
 19#include <linux/moduleparam.h>
 20#include <linux/iommu.h>
 21#include <net/ip.h>
 22#include <net/checksum.h>
 
 
 23#include "net_driver.h"
 24#include "efx.h"
 
 25#include "filter.h"
 26#include "nic.h"
 27#include "selftest.h"
 28#include "workarounds.h"
 29
 30/* Preferred number of descriptors to fill at once */
 31#define EFX_RX_PREFERRED_BATCH 8U
 32
 33/* Number of RX buffers to recycle pages for.  When creating the RX page recycle
 34 * ring, this number is divided by the number of buffers per page to calculate
 35 * the number of pages to store in the RX page recycle ring.
 36 */
 37#define EFX_RECYCLE_RING_SIZE_IOMMU 4096
 38#define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH)
 39
 40/* Size of buffer allocated for skb header area. */
 41#define EFX_SKB_HEADERS  128u
 42
 43/* This is the percentage fill level below which new RX descriptors
 44 * will be added to the RX descriptor ring.
 45 */
 46static unsigned int rx_refill_threshold;
 47
 48/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
 49#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
 50				      EFX_RX_USR_BUF_SIZE)
 51
 52/*
 53 * RX maximum head room required.
 54 *
 55 * This must be at least 1 to prevent overflow, plus one packet-worth
 56 * to allow pipelined receives.
 57 */
 58#define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
 59
 60static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf)
 61{
 62	return page_address(buf->page) + buf->page_offset;
 63}
 64
 65static inline u32 efx_rx_buf_hash(struct efx_nic *efx, const u8 *eh)
 66{
 67#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 68	return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_hash_offset));
 69#else
 70	const u8 *data = eh + efx->rx_packet_hash_offset;
 71	return (u32)data[0]	  |
 72	       (u32)data[1] << 8  |
 73	       (u32)data[2] << 16 |
 74	       (u32)data[3] << 24;
 75#endif
 76}
 77
 78static inline struct efx_rx_buffer *
 79efx_rx_buf_next(struct efx_rx_queue *rx_queue, struct efx_rx_buffer *rx_buf)
 80{
 81	if (unlikely(rx_buf == efx_rx_buffer(rx_queue, rx_queue->ptr_mask)))
 82		return efx_rx_buffer(rx_queue, 0);
 83	else
 84		return rx_buf + 1;
 85}
 86
 87static inline void efx_sync_rx_buffer(struct efx_nic *efx,
 88				      struct efx_rx_buffer *rx_buf,
 89				      unsigned int len)
 90{
 91	dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, len,
 92				DMA_FROM_DEVICE);
 93}
 94
 95void efx_rx_config_page_split(struct efx_nic *efx)
 96{
 97	efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
 98				      EFX_RX_BUF_ALIGNMENT);
 99	efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
100		((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
101		 efx->rx_page_buf_step);
102	efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
103		efx->rx_bufs_per_page;
104	efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
105					       efx->rx_bufs_per_page);
106}
107
108/* Check the RX page recycle ring for a page that can be reused. */
109static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
110{
111	struct efx_nic *efx = rx_queue->efx;
112	struct page *page;
113	struct efx_rx_page_state *state;
114	unsigned index;
115
116	index = rx_queue->page_remove & rx_queue->page_ptr_mask;
117	page = rx_queue->page_ring[index];
118	if (page == NULL)
119		return NULL;
120
121	rx_queue->page_ring[index] = NULL;
122	/* page_remove cannot exceed page_add. */
123	if (rx_queue->page_remove != rx_queue->page_add)
124		++rx_queue->page_remove;
125
126	/* If page_count is 1 then we hold the only reference to this page. */
127	if (page_count(page) == 1) {
128		++rx_queue->page_recycle_count;
129		return page;
130	} else {
131		state = page_address(page);
132		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
133			       PAGE_SIZE << efx->rx_buffer_order,
134			       DMA_FROM_DEVICE);
135		put_page(page);
136		++rx_queue->page_recycle_failed;
137	}
138
139	return NULL;
140}
141
142/**
143 * efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
144 *
145 * @rx_queue:		Efx RX queue
146 *
147 * This allocates a batch of pages, maps them for DMA, and populates
148 * struct efx_rx_buffers for each one. Return a negative error code or
149 * 0 on success. If a single page can be used for multiple buffers,
150 * then the page will either be inserted fully, or not at all.
151 */
152static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
153{
154	struct efx_nic *efx = rx_queue->efx;
155	struct efx_rx_buffer *rx_buf;
156	struct page *page;
157	unsigned int page_offset;
158	struct efx_rx_page_state *state;
159	dma_addr_t dma_addr;
160	unsigned index, count;
161
162	count = 0;
163	do {
164		page = efx_reuse_page(rx_queue);
165		if (page == NULL) {
166			page = alloc_pages(__GFP_COLD | __GFP_COMP |
167					   (atomic ? GFP_ATOMIC : GFP_KERNEL),
168					   efx->rx_buffer_order);
169			if (unlikely(page == NULL))
170				return -ENOMEM;
171			dma_addr =
172				dma_map_page(&efx->pci_dev->dev, page, 0,
173					     PAGE_SIZE << efx->rx_buffer_order,
174					     DMA_FROM_DEVICE);
175			if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
176						       dma_addr))) {
177				__free_pages(page, efx->rx_buffer_order);
178				return -EIO;
179			}
180			state = page_address(page);
181			state->dma_addr = dma_addr;
182		} else {
183			state = page_address(page);
184			dma_addr = state->dma_addr;
185		}
186
187		dma_addr += sizeof(struct efx_rx_page_state);
188		page_offset = sizeof(struct efx_rx_page_state);
189
190		do {
191			index = rx_queue->added_count & rx_queue->ptr_mask;
192			rx_buf = efx_rx_buffer(rx_queue, index);
193			rx_buf->dma_addr = dma_addr + efx->rx_ip_align;
194			rx_buf->page = page;
195			rx_buf->page_offset = page_offset + efx->rx_ip_align;
196			rx_buf->len = efx->rx_dma_len;
197			rx_buf->flags = 0;
198			++rx_queue->added_count;
199			get_page(page);
200			dma_addr += efx->rx_page_buf_step;
201			page_offset += efx->rx_page_buf_step;
202		} while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
203
204		rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
205	} while (++count < efx->rx_pages_per_batch);
206
207	return 0;
208}
209
210/* Unmap a DMA-mapped page.  This function is only called for the final RX
211 * buffer in a page.
212 */
213static void efx_unmap_rx_buffer(struct efx_nic *efx,
214				struct efx_rx_buffer *rx_buf)
215{
216	struct page *page = rx_buf->page;
217
218	if (page) {
219		struct efx_rx_page_state *state = page_address(page);
220		dma_unmap_page(&efx->pci_dev->dev,
221			       state->dma_addr,
222			       PAGE_SIZE << efx->rx_buffer_order,
223			       DMA_FROM_DEVICE);
224	}
225}
226
227static void efx_free_rx_buffer(struct efx_rx_buffer *rx_buf)
228{
229	if (rx_buf->page) {
230		put_page(rx_buf->page);
231		rx_buf->page = NULL;
232	}
233}
234
235/* Attempt to recycle the page if there is an RX recycle ring; the page can
236 * only be added if this is the final RX buffer, to prevent pages being used in
237 * the descriptor ring and appearing in the recycle ring simultaneously.
238 */
239static void efx_recycle_rx_page(struct efx_channel *channel,
240				struct efx_rx_buffer *rx_buf)
241{
242	struct page *page = rx_buf->page;
243	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
244	struct efx_nic *efx = rx_queue->efx;
245	unsigned index;
246
247	/* Only recycle the page after processing the final buffer. */
248	if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
249		return;
250
251	index = rx_queue->page_add & rx_queue->page_ptr_mask;
252	if (rx_queue->page_ring[index] == NULL) {
253		unsigned read_index = rx_queue->page_remove &
254			rx_queue->page_ptr_mask;
255
256		/* The next slot in the recycle ring is available, but
257		 * increment page_remove if the read pointer currently
258		 * points here.
259		 */
260		if (read_index == index)
261			++rx_queue->page_remove;
262		rx_queue->page_ring[index] = page;
263		++rx_queue->page_add;
264		return;
265	}
266	++rx_queue->page_recycle_full;
267	efx_unmap_rx_buffer(efx, rx_buf);
268	put_page(rx_buf->page);
269}
270
271static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
272			       struct efx_rx_buffer *rx_buf)
273{
274	/* Release the page reference we hold for the buffer. */
275	if (rx_buf->page)
276		put_page(rx_buf->page);
277
278	/* If this is the last buffer in a page, unmap and free it. */
279	if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
280		efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
281		efx_free_rx_buffer(rx_buf);
282	}
283	rx_buf->page = NULL;
284}
285
286/* Recycle the pages that are used by buffers that have just been received. */
287static void efx_recycle_rx_pages(struct efx_channel *channel,
288				 struct efx_rx_buffer *rx_buf,
289				 unsigned int n_frags)
290{
291	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
292
293	do {
294		efx_recycle_rx_page(channel, rx_buf);
295		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
296	} while (--n_frags);
297}
298
299static void efx_discard_rx_packet(struct efx_channel *channel,
300				  struct efx_rx_buffer *rx_buf,
301				  unsigned int n_frags)
302{
303	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
304
305	efx_recycle_rx_pages(channel, rx_buf, n_frags);
306
307	do {
308		efx_free_rx_buffer(rx_buf);
309		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
310	} while (--n_frags);
311}
312
313/**
314 * efx_fast_push_rx_descriptors - push new RX descriptors quickly
315 * @rx_queue:		RX descriptor queue
316 *
317 * This will aim to fill the RX descriptor queue up to
318 * @rx_queue->@max_fill. If there is insufficient atomic
319 * memory to do so, a slow fill will be scheduled.
320 *
321 * The caller must provide serialisation (none is used here). In practise,
322 * this means this function must run from the NAPI handler, or be called
323 * when NAPI is disabled.
324 */
325void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
326{
327	struct efx_nic *efx = rx_queue->efx;
328	unsigned int fill_level, batch_size;
329	int space, rc = 0;
330
331	if (!rx_queue->refill_enabled)
332		return;
333
334	/* Calculate current fill level, and exit if we don't need to fill */
335	fill_level = (rx_queue->added_count - rx_queue->removed_count);
336	EFX_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries);
337	if (fill_level >= rx_queue->fast_fill_trigger)
338		goto out;
339
340	/* Record minimum fill level */
341	if (unlikely(fill_level < rx_queue->min_fill)) {
342		if (fill_level)
343			rx_queue->min_fill = fill_level;
344	}
345
346	batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
347	space = rx_queue->max_fill - fill_level;
348	EFX_BUG_ON_PARANOID(space < batch_size);
349
350	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
351		   "RX queue %d fast-filling descriptor ring from"
352		   " level %d to level %d\n",
353		   efx_rx_queue_index(rx_queue), fill_level,
354		   rx_queue->max_fill);
355
356
357	do {
358		rc = efx_init_rx_buffers(rx_queue, atomic);
359		if (unlikely(rc)) {
360			/* Ensure that we don't leave the rx queue empty */
361			if (rx_queue->added_count == rx_queue->removed_count)
362				efx_schedule_slow_fill(rx_queue);
363			goto out;
364		}
365	} while ((space -= batch_size) >= batch_size);
366
367	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
368		   "RX queue %d fast-filled descriptor ring "
369		   "to level %d\n", efx_rx_queue_index(rx_queue),
370		   rx_queue->added_count - rx_queue->removed_count);
371
372 out:
373	if (rx_queue->notified_count != rx_queue->added_count)
374		efx_nic_notify_rx_desc(rx_queue);
375}
376
377void efx_rx_slow_fill(unsigned long context)
378{
379	struct efx_rx_queue *rx_queue = (struct efx_rx_queue *)context;
380
381	/* Post an event to cause NAPI to run and refill the queue */
382	efx_nic_generate_fill_event(rx_queue);
383	++rx_queue->slow_fill_count;
384}
385
386static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
387				     struct efx_rx_buffer *rx_buf,
388				     int len)
389{
390	struct efx_nic *efx = rx_queue->efx;
391	unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
392
393	if (likely(len <= max_len))
394		return;
395
396	/* The packet must be discarded, but this is only a fatal error
397	 * if the caller indicated it was
398	 */
399	rx_buf->flags |= EFX_RX_PKT_DISCARD;
400
401	if ((len > rx_buf->len) && EFX_WORKAROUND_8071(efx)) {
402		if (net_ratelimit())
403			netif_err(efx, rx_err, efx->net_dev,
404				  " RX queue %d seriously overlength "
405				  "RX event (0x%x > 0x%x+0x%x). Leaking\n",
406				  efx_rx_queue_index(rx_queue), len, max_len,
407				  efx->type->rx_buffer_padding);
408		efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
409	} else {
410		if (net_ratelimit())
411			netif_err(efx, rx_err, efx->net_dev,
412				  " RX queue %d overlength RX event "
413				  "(0x%x > 0x%x)\n",
414				  efx_rx_queue_index(rx_queue), len, max_len);
415	}
416
417	efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
418}
419
420/* Pass a received packet up through GRO.  GRO can handle pages
421 * regardless of checksum state and skbs with a good checksum.
422 */
423static void
424efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
425		  unsigned int n_frags, u8 *eh)
426{
427	struct napi_struct *napi = &channel->napi_str;
428	gro_result_t gro_result;
429	struct efx_nic *efx = channel->efx;
430	struct sk_buff *skb;
431
432	skb = napi_get_frags(napi);
433	if (unlikely(!skb)) {
434		while (n_frags--) {
435			put_page(rx_buf->page);
436			rx_buf->page = NULL;
437			rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
438		}
439		return;
440	}
441
442	if (efx->net_dev->features & NETIF_F_RXHASH)
443		skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
444			     PKT_HASH_TYPE_L3);
445	skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
446			  CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
447
448	for (;;) {
449		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
450				   rx_buf->page, rx_buf->page_offset,
451				   rx_buf->len);
452		rx_buf->page = NULL;
453		skb->len += rx_buf->len;
454		if (skb_shinfo(skb)->nr_frags == n_frags)
455			break;
456
457		rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
458	}
459
460	skb->data_len = skb->len;
461	skb->truesize += n_frags * efx->rx_buffer_truesize;
462
463	skb_record_rx_queue(skb, channel->rx_queue.core_index);
464
465	gro_result = napi_gro_frags(napi);
466	if (gro_result != GRO_DROP)
467		channel->irq_mod_score += 2;
468}
469
470/* Allocate and construct an SKB around page fragments */
471static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
472				     struct efx_rx_buffer *rx_buf,
473				     unsigned int n_frags,
474				     u8 *eh, int hdr_len)
475{
476	struct efx_nic *efx = channel->efx;
477	struct sk_buff *skb;
478
479	/* Allocate an SKB to store the headers */
480	skb = netdev_alloc_skb(efx->net_dev,
481			       efx->rx_ip_align + efx->rx_prefix_size +
482			       hdr_len);
483	if (unlikely(skb == NULL))
 
484		return NULL;
 
485
486	EFX_BUG_ON_PARANOID(rx_buf->len < hdr_len);
487
488	memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
489	       efx->rx_prefix_size + hdr_len);
490	skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
491	__skb_put(skb, hdr_len);
492
493	/* Append the remaining page(s) onto the frag list */
494	if (rx_buf->len > hdr_len) {
495		rx_buf->page_offset += hdr_len;
496		rx_buf->len -= hdr_len;
497
498		for (;;) {
499			skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
500					   rx_buf->page, rx_buf->page_offset,
501					   rx_buf->len);
502			rx_buf->page = NULL;
503			skb->len += rx_buf->len;
504			skb->data_len += rx_buf->len;
505			if (skb_shinfo(skb)->nr_frags == n_frags)
506				break;
507
508			rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
509		}
510	} else {
511		__free_pages(rx_buf->page, efx->rx_buffer_order);
512		rx_buf->page = NULL;
513		n_frags = 0;
514	}
515
516	skb->truesize += n_frags * efx->rx_buffer_truesize;
517
518	/* Move past the ethernet header */
519	skb->protocol = eth_type_trans(skb, efx->net_dev);
520
 
 
521	return skb;
522}
523
524void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
525		   unsigned int n_frags, unsigned int len, u16 flags)
526{
527	struct efx_nic *efx = rx_queue->efx;
528	struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
529	struct efx_rx_buffer *rx_buf;
530
 
 
531	rx_buf = efx_rx_buffer(rx_queue, index);
532	rx_buf->flags |= flags;
533
534	/* Validate the number of fragments and completed length */
535	if (n_frags == 1) {
536		if (!(flags & EFX_RX_PKT_PREFIX_LEN))
537			efx_rx_packet__check_len(rx_queue, rx_buf, len);
538	} else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
539		   unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
540		   unlikely(len > n_frags * efx->rx_dma_len) ||
541		   unlikely(!efx->rx_scatter)) {
542		/* If this isn't an explicit discard request, either
543		 * the hardware or the driver is broken.
544		 */
545		WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
546		rx_buf->flags |= EFX_RX_PKT_DISCARD;
547	}
548
549	netif_vdbg(efx, rx_status, efx->net_dev,
550		   "RX queue %d received ids %x-%x len %d %s%s\n",
551		   efx_rx_queue_index(rx_queue), index,
552		   (index + n_frags - 1) & rx_queue->ptr_mask, len,
553		   (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
554		   (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
555
556	/* Discard packet, if instructed to do so.  Process the
557	 * previous receive first.
558	 */
559	if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
560		efx_rx_flush_packet(channel);
561		efx_discard_rx_packet(channel, rx_buf, n_frags);
562		return;
563	}
564
565	if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))
566		rx_buf->len = len;
567
568	/* Release and/or sync the DMA mapping - assumes all RX buffers
569	 * consumed in-order per RX queue.
570	 */
571	efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
572
573	/* Prefetch nice and early so data will (hopefully) be in cache by
574	 * the time we look at it.
575	 */
576	prefetch(efx_rx_buf_va(rx_buf));
577
578	rx_buf->page_offset += efx->rx_prefix_size;
579	rx_buf->len -= efx->rx_prefix_size;
580
581	if (n_frags > 1) {
582		/* Release/sync DMA mapping for additional fragments.
583		 * Fix length for last fragment.
584		 */
585		unsigned int tail_frags = n_frags - 1;
586
587		for (;;) {
588			rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
589			if (--tail_frags == 0)
590				break;
591			efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
592		}
593		rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
594		efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
595	}
596
597	/* All fragments have been DMA-synced, so recycle pages. */
598	rx_buf = efx_rx_buffer(rx_queue, index);
599	efx_recycle_rx_pages(channel, rx_buf, n_frags);
600
601	/* Pipeline receives so that we give time for packet headers to be
602	 * prefetched into cache.
603	 */
604	efx_rx_flush_packet(channel);
605	channel->rx_pkt_n_frags = n_frags;
606	channel->rx_pkt_index = index;
607}
608
609static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
610			   struct efx_rx_buffer *rx_buf,
611			   unsigned int n_frags)
612{
613	struct sk_buff *skb;
614	u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
615
616	skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
617	if (unlikely(skb == NULL)) {
618		efx_free_rx_buffer(rx_buf);
 
 
 
619		return;
620	}
621	skb_record_rx_queue(skb, channel->rx_queue.core_index);
622
623	/* Set the SKB flags */
624	skb_checksum_none_assert(skb);
625	if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED))
626		skb->ip_summed = CHECKSUM_UNNECESSARY;
 
 
627
628	efx_rx_skb_attach_timestamp(channel, skb);
629
630	if (channel->type->receive_skb)
631		if (channel->type->receive_skb(channel, skb))
632			return;
633
634	/* Pass the packet up */
635	netif_receive_skb(skb);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
636}
637
638/* Handle a received packet.  Second half: Touches packet payload. */
639void __efx_rx_packet(struct efx_channel *channel)
640{
 
641	struct efx_nic *efx = channel->efx;
642	struct efx_rx_buffer *rx_buf =
643		efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
644	u8 *eh = efx_rx_buf_va(rx_buf);
645
646	/* Read length from the prefix if necessary.  This already
647	 * excludes the length of the prefix itself.
648	 */
649	if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN)
650		rx_buf->len = le16_to_cpup((__le16 *)
651					   (eh + efx->rx_packet_len_offset));
 
 
 
 
 
 
 
 
 
 
 
 
652
653	/* If we're in loopback test, then pass the packet directly to the
654	 * loopback layer, and free the rx_buf here
655	 */
656	if (unlikely(efx->loopback_selftest)) {
657		efx_loopback_rx_packet(efx, eh, rx_buf->len);
658		efx_free_rx_buffer(rx_buf);
 
659		goto out;
660	}
661
 
 
 
662	if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
663		rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
664
665	if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)
666		efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
667	else
668		efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
669out:
670	channel->rx_pkt_n_frags = 0;
671}
672
673int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
674{
675	struct efx_nic *efx = rx_queue->efx;
676	unsigned int entries;
677	int rc;
678
679	/* Create the smallest power-of-two aligned ring */
680	entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
681	EFX_BUG_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
682	rx_queue->ptr_mask = entries - 1;
683
684	netif_dbg(efx, probe, efx->net_dev,
685		  "creating RX queue %d size %#x mask %#x\n",
686		  efx_rx_queue_index(rx_queue), efx->rxq_entries,
687		  rx_queue->ptr_mask);
688
689	/* Allocate RX buffers */
690	rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
691				   GFP_KERNEL);
692	if (!rx_queue->buffer)
693		return -ENOMEM;
694
695	rc = efx_nic_probe_rx(rx_queue);
696	if (rc) {
697		kfree(rx_queue->buffer);
698		rx_queue->buffer = NULL;
699	}
700
701	return rc;
702}
703
704static void efx_init_rx_recycle_ring(struct efx_nic *efx,
705				     struct efx_rx_queue *rx_queue)
706{
707	unsigned int bufs_in_recycle_ring, page_ring_size;
708
709	/* Set the RX recycle ring size */
710#ifdef CONFIG_PPC64
711	bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
712#else
713	if (iommu_present(&pci_bus_type))
714		bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
715	else
716		bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU;
717#endif /* CONFIG_PPC64 */
718
719	page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
720					    efx->rx_bufs_per_page);
721	rx_queue->page_ring = kcalloc(page_ring_size,
722				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
723	rx_queue->page_ptr_mask = page_ring_size - 1;
724}
725
726void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
727{
728	struct efx_nic *efx = rx_queue->efx;
729	unsigned int max_fill, trigger, max_trigger;
730
731	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
732		  "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
733
734	/* Initialise ptr fields */
735	rx_queue->added_count = 0;
736	rx_queue->notified_count = 0;
737	rx_queue->removed_count = 0;
738	rx_queue->min_fill = -1U;
739	efx_init_rx_recycle_ring(efx, rx_queue);
740
741	rx_queue->page_remove = 0;
742	rx_queue->page_add = rx_queue->page_ptr_mask + 1;
743	rx_queue->page_recycle_count = 0;
744	rx_queue->page_recycle_failed = 0;
745	rx_queue->page_recycle_full = 0;
746
747	/* Initialise limit fields */
748	max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
749	max_trigger =
750		max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
751	if (rx_refill_threshold != 0) {
752		trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
753		if (trigger > max_trigger)
754			trigger = max_trigger;
755	} else {
756		trigger = max_trigger;
757	}
758
759	rx_queue->max_fill = max_fill;
760	rx_queue->fast_fill_trigger = trigger;
761	rx_queue->refill_enabled = true;
762
763	/* Set up RX descriptor ring */
764	efx_nic_init_rx(rx_queue);
765}
766
767void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
768{
769	int i;
770	struct efx_nic *efx = rx_queue->efx;
771	struct efx_rx_buffer *rx_buf;
772
773	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
774		  "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
775
776	del_timer_sync(&rx_queue->slow_fill);
777
778	/* Release RX buffers from the current read ptr to the write ptr */
779	if (rx_queue->buffer) {
780		for (i = rx_queue->removed_count; i < rx_queue->added_count;
781		     i++) {
782			unsigned index = i & rx_queue->ptr_mask;
783			rx_buf = efx_rx_buffer(rx_queue, index);
784			efx_fini_rx_buffer(rx_queue, rx_buf);
785		}
786	}
787
788	/* Unmap and release the pages in the recycle ring. Remove the ring. */
789	for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
790		struct page *page = rx_queue->page_ring[i];
791		struct efx_rx_page_state *state;
792
793		if (page == NULL)
794			continue;
795
796		state = page_address(page);
797		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
798			       PAGE_SIZE << efx->rx_buffer_order,
799			       DMA_FROM_DEVICE);
800		put_page(page);
801	}
802	kfree(rx_queue->page_ring);
803	rx_queue->page_ring = NULL;
804}
805
806void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
807{
808	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
809		  "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
810
811	efx_nic_remove_rx(rx_queue);
812
813	kfree(rx_queue->buffer);
814	rx_queue->buffer = NULL;
815}
816
817
818module_param(rx_refill_threshold, uint, 0444);
819MODULE_PARM_DESC(rx_refill_threshold,
820		 "RX descriptor ring refill threshold (%)");
821
822#ifdef CONFIG_RFS_ACCEL
823
824int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
825		   u16 rxq_index, u32 flow_id)
826{
827	struct efx_nic *efx = netdev_priv(net_dev);
828	struct efx_channel *channel;
829	struct efx_filter_spec spec;
830	const __be16 *ports;
831	__be16 ether_type;
832	int nhoff;
833	int rc;
834
835	/* The core RPS/RFS code has already parsed and validated
836	 * VLAN, IP and transport headers.  We assume they are in the
837	 * header area.
838	 */
839
840	if (skb->protocol == htons(ETH_P_8021Q)) {
841		const struct vlan_hdr *vh =
842			(const struct vlan_hdr *)skb->data;
843
844		/* We can't filter on the IP 5-tuple and the vlan
845		 * together, so just strip the vlan header and filter
846		 * on the IP part.
847		 */
848		EFX_BUG_ON_PARANOID(skb_headlen(skb) < sizeof(*vh));
849		ether_type = vh->h_vlan_encapsulated_proto;
850		nhoff = sizeof(struct vlan_hdr);
851	} else {
852		ether_type = skb->protocol;
853		nhoff = 0;
854	}
855
856	if (ether_type != htons(ETH_P_IP) && ether_type != htons(ETH_P_IPV6))
857		return -EPROTONOSUPPORT;
858
859	efx_filter_init_rx(&spec, EFX_FILTER_PRI_HINT,
860			   efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
861			   rxq_index);
862	spec.match_flags =
863		EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
864		EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
865		EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
866	spec.ether_type = ether_type;
867
868	if (ether_type == htons(ETH_P_IP)) {
869		const struct iphdr *ip =
870			(const struct iphdr *)(skb->data + nhoff);
871
872		EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + sizeof(*ip));
873		if (ip_is_fragment(ip))
874			return -EPROTONOSUPPORT;
875		spec.ip_proto = ip->protocol;
876		spec.rem_host[0] = ip->saddr;
877		spec.loc_host[0] = ip->daddr;
878		EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + 4 * ip->ihl + 4);
879		ports = (const __be16 *)(skb->data + nhoff + 4 * ip->ihl);
880	} else {
881		const struct ipv6hdr *ip6 =
882			(const struct ipv6hdr *)(skb->data + nhoff);
883
884		EFX_BUG_ON_PARANOID(skb_headlen(skb) <
885				    nhoff + sizeof(*ip6) + 4);
886		spec.ip_proto = ip6->nexthdr;
887		memcpy(spec.rem_host, &ip6->saddr, sizeof(ip6->saddr));
888		memcpy(spec.loc_host, &ip6->daddr, sizeof(ip6->daddr));
889		ports = (const __be16 *)(ip6 + 1);
890	}
891
892	spec.rem_port = ports[0];
893	spec.loc_port = ports[1];
894
895	rc = efx->type->filter_rfs_insert(efx, &spec);
896	if (rc < 0)
897		return rc;
898
899	/* Remember this so we can check whether to expire the filter later */
900	efx->rps_flow_id[rc] = flow_id;
901	channel = efx_get_channel(efx, skb_get_rx_queue(skb));
902	++channel->rfs_filters_added;
903
904	if (ether_type == htons(ETH_P_IP))
905		netif_info(efx, rx_status, efx->net_dev,
906			   "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d]\n",
907			   (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
908			   spec.rem_host, ntohs(ports[0]), spec.loc_host,
909			   ntohs(ports[1]), rxq_index, flow_id, rc);
910	else
911		netif_info(efx, rx_status, efx->net_dev,
912			   "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
913			   (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
914			   spec.rem_host, ntohs(ports[0]), spec.loc_host,
915			   ntohs(ports[1]), rxq_index, flow_id, rc);
916
917	return rc;
918}
919
920bool __efx_filter_rfs_expire(struct efx_nic *efx, unsigned int quota)
921{
922	bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
923	unsigned int index, size;
924	u32 flow_id;
925
926	if (!spin_trylock_bh(&efx->filter_lock))
927		return false;
928
929	expire_one = efx->type->filter_rfs_expire_one;
930	index = efx->rps_expire_index;
931	size = efx->type->max_rx_ip_filters;
932	while (quota--) {
933		flow_id = efx->rps_flow_id[index];
934		if (expire_one(efx, flow_id, index))
935			netif_info(efx, rx_status, efx->net_dev,
936				   "expired filter %d [flow %u]\n",
937				   index, flow_id);
938		if (++index == size)
939			index = 0;
940	}
941	efx->rps_expire_index = index;
942
943	spin_unlock_bh(&efx->filter_lock);
944	return true;
945}
946
947#endif /* CONFIG_RFS_ACCEL */
948
949/**
950 * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
951 * @spec: Specification to test
952 *
953 * Return: %true if the specification is a non-drop RX filter that
954 * matches a local MAC address I/G bit value of 1 or matches a local
955 * IPv4 or IPv6 address value in the respective multicast address
956 * range.  Otherwise %false.
957 */
958bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
959{
960	if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
961	    spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
962		return false;
963
964	if (spec->match_flags &
965	    (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
966	    is_multicast_ether_addr(spec->loc_mac))
967		return true;
968
969	if ((spec->match_flags &
970	     (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
971	    (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
972		if (spec->ether_type == htons(ETH_P_IP) &&
973		    ipv4_is_multicast(spec->loc_host[0]))
974			return true;
975		if (spec->ether_type == htons(ETH_P_IPV6) &&
976		    ((const u8 *)spec->loc_host)[0] == 0xff)
977			return true;
978	}
979
980	return false;
981}