summaryrefslogtreecommitdiff
path: root/net/xdp/xsk_buff_pool.c
blob: a2044c2452152a4f040801c161bfb27a21a11bf3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
// SPDX-License-Identifier: GPL-2.0

#include <net/xsk_buff_pool.h>
#include <net/xdp_sock.h>

#include "xsk_queue.h"

static void xp_addr_unmap(struct xsk_buff_pool *pool)
{
	vunmap(pool->addrs);
}

static int xp_addr_map(struct xsk_buff_pool *pool,
		       struct page **pages, u32 nr_pages)
{
	pool->addrs = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
	if (!pool->addrs)
		return -ENOMEM;
	return 0;
}

void xp_destroy(struct xsk_buff_pool *pool)
{
	if (!pool)
		return;

	xp_addr_unmap(pool);
	kvfree(pool->heads);
	kvfree(pool);
}

struct xsk_buff_pool *xp_create(struct page **pages, u32 nr_pages, u32 chunks,
				u32 chunk_size, u32 headroom, u64 size,
				bool unaligned)
{
	struct xsk_buff_pool *pool;
	struct xdp_buff_xsk *xskb;
	int err;
	u32 i;

	pool = kvzalloc(struct_size(pool, free_heads, chunks), GFP_KERNEL);
	if (!pool)
		goto out;

	pool->heads = kvcalloc(chunks, sizeof(*pool->heads), GFP_KERNEL);
	if (!pool->heads)
		goto out;

	pool->chunk_mask = ~((u64)chunk_size - 1);
	pool->addrs_cnt = size;
	pool->heads_cnt = chunks;
	pool->free_heads_cnt = chunks;
	pool->headroom = headroom;
	pool->chunk_size = chunk_size;
	pool->unaligned = unaligned;
	pool->frame_len = chunk_size - headroom - XDP_PACKET_HEADROOM;
	INIT_LIST_HEAD(&pool->free_list);

	for (i = 0; i < pool->free_heads_cnt; i++) {
		xskb = &pool->heads[i];
		xskb->pool = pool;
		xskb->xdp.frame_sz = chunk_size - headroom;
		pool->free_heads[i] = xskb;
	}

	err = xp_addr_map(pool, pages, nr_pages);
	if (!err)
		return pool;

out:
	xp_destroy(pool);
	return NULL;
}

void xp_set_fq(struct xsk_buff_pool *pool, struct xsk_queue *fq)
{
	pool->fq = fq;
}

void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
{
	u32 i;

	for (i = 0; i < pool->heads_cnt; i++)
		pool->heads[i].xdp.rxq = rxq;
}
EXPORT_SYMBOL(xp_set_rxq_info);

void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
{
	dma_addr_t *dma;
	u32 i;

	if (pool->dma_pages_cnt == 0)
		return;

	for (i = 0; i < pool->dma_pages_cnt; i++) {
		dma = &pool->dma_pages[i];
		if (*dma) {
			dma_unmap_page_attrs(pool->dev, *dma, PAGE_SIZE,
					     DMA_BIDIRECTIONAL, attrs);
			*dma = 0;
		}
	}

	kvfree(pool->dma_pages);
	pool->dma_pages_cnt = 0;
	pool->dev = NULL;
}
EXPORT_SYMBOL(xp_dma_unmap);

static void xp_check_dma_contiguity(struct xsk_buff_pool *pool)
{
	u32 i;

	for (i = 0; i < pool->dma_pages_cnt - 1; i++) {
		if (pool->dma_pages[i] + PAGE_SIZE == pool->dma_pages[i + 1])
			pool->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
		else
			pool->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
	}
}

int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
	       unsigned long attrs, struct page **pages, u32 nr_pages)
{
	dma_addr_t dma;
	u32 i;

	pool->dma_pages = kvcalloc(nr_pages, sizeof(*pool->dma_pages),
				   GFP_KERNEL);
	if (!pool->dma_pages)
		return -ENOMEM;

	pool->dev = dev;
	pool->dma_pages_cnt = nr_pages;
	pool->dma_need_sync = false;

	for (i = 0; i < pool->dma_pages_cnt; i++) {
		dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
					 DMA_BIDIRECTIONAL, attrs);
		if (dma_mapping_error(dev, dma)) {
			xp_dma_unmap(pool, attrs);
			return -ENOMEM;
		}
		if (dma_need_sync(dev, dma))
			pool->dma_need_sync = true;
		pool->dma_pages[i] = dma;
	}

	if (pool->unaligned)
		xp_check_dma_contiguity(pool);
	return 0;
}
EXPORT_SYMBOL(xp_dma_map);

static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
					  u64 addr)
{
	return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
}

static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
{
	*addr = xp_unaligned_extract_addr(*addr);
	if (*addr >= pool->addrs_cnt ||
	    *addr + pool->chunk_size > pool->addrs_cnt ||
	    xp_addr_crosses_non_contig_pg(pool, *addr))
		return false;
	return true;
}

static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
{
	*addr = xp_aligned_extract_addr(pool, *addr);
	return *addr < pool->addrs_cnt;
}

static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
{
	struct xdp_buff_xsk *xskb;
	u64 addr;
	bool ok;

	if (pool->free_heads_cnt == 0)
		return NULL;

	xskb = pool->free_heads[--pool->free_heads_cnt];

	for (;;) {
		if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
			pool->fq->queue_empty_descs++;
			xp_release(xskb);
			return NULL;
		}

		ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
		     xp_check_aligned(pool, &addr);
		if (!ok) {
			pool->fq->invalid_descs++;
			xskq_cons_release(pool->fq);
			continue;
		}
		break;
	}
	xskq_cons_release(pool->fq);

	xskb->orig_addr = addr;
	xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
	if (pool->dma_pages_cnt) {
		xskb->frame_dma = (pool->dma_pages[addr >> PAGE_SHIFT] &
				   ~XSK_NEXT_PG_CONTIG_MASK) +
				  (addr & ~PAGE_MASK);
		xskb->dma = xskb->frame_dma + pool->headroom +
			    XDP_PACKET_HEADROOM;
	}
	return xskb;
}

struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
{
	struct xdp_buff_xsk *xskb;

	if (!pool->free_list_cnt) {
		xskb = __xp_alloc(pool);
		if (!xskb)
			return NULL;
	} else {
		pool->free_list_cnt--;
		xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
					free_list_node);
		list_del(&xskb->free_list_node);
	}

	xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
	xskb->xdp.data_meta = xskb->xdp.data;

	if (pool->dma_need_sync) {
		dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
						 pool->frame_len,
						 DMA_BIDIRECTIONAL);
	}
	return &xskb->xdp;
}
EXPORT_SYMBOL(xp_alloc);

bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
{
	if (pool->free_list_cnt >= count)
		return true;
	return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
}
EXPORT_SYMBOL(xp_can_alloc);

void xp_free(struct xdp_buff_xsk *xskb)
{
	xskb->pool->free_list_cnt++;
	list_add(&xskb->free_list_node, &xskb->pool->free_list);
}
EXPORT_SYMBOL(xp_free);

void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
{
	addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
	return pool->addrs + addr;
}
EXPORT_SYMBOL(xp_raw_get_data);

dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
{
	addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
	return (pool->dma_pages[addr >> PAGE_SHIFT] &
		~XSK_NEXT_PG_CONTIG_MASK) +
		(addr & ~PAGE_MASK);
}
EXPORT_SYMBOL(xp_raw_get_dma);

void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
{
	dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
				      xskb->pool->frame_len, DMA_BIDIRECTIONAL);
}
EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);

void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
				 size_t size)
{
	dma_sync_single_range_for_device(pool->dev, dma, 0,
					 size, DMA_BIDIRECTIONAL);
}
EXPORT_SYMBOL(xp_dma_sync_for_device_slow);