1 // SPDX-License-Identifier: GPL-2.0
2 /* XDP user-space ring structure
3 * Copyright(c) 2018 Intel Corporation.
4 */
5
6 #include <linux/log2.h>
7 #include <linux/slab.h>
8 #include <linux/overflow.h>
9 #include <linux/vmalloc.h>
10 #include <net/xdp_sock_drv.h>
11
12 #include <asm/shmparam.h>
13
14 #include "xsk_queue.h"
15
xskq_get_ring_size(struct xsk_queue * q,bool umem_queue)16 static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
17 {
18 struct xdp_umem_ring *umem_ring;
19 struct xdp_rxtx_ring *rxtx_ring;
20
21 if (umem_queue)
22 return struct_size(umem_ring, desc, q->nentries);
23 return struct_size(rxtx_ring, desc, q->nentries);
24 }
25
xskq_vmalloc_user(unsigned long size)26 static void *xskq_vmalloc_user(unsigned long size)
27 {
28 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
29 GFP_KERNEL_ACCOUNT | __GFP_ZERO, PAGE_KERNEL,
30 VM_USERMAP, NUMA_NO_NODE,
31 __builtin_return_address(0));
32 }
33
xskq_create(u32 nentries,bool umem_queue)34 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
35 {
36 struct xsk_queue *q;
37 size_t size;
38
39 q = kzalloc_obj(*q);
40 if (!q)
41 return NULL;
42
43 q->nentries = nentries;
44 q->ring_mask = nentries - 1;
45
46 size = xskq_get_ring_size(q, umem_queue);
47
48 /* size which is overflowing or close to SIZE_MAX will become 0 in
49 * PAGE_ALIGN(), checking SIZE_MAX is enough due to the previous
50 * is_power_of_2(), the rest will be handled by vmalloc_user()
51 */
52 if (unlikely(size == SIZE_MAX)) {
53 kfree(q);
54 return NULL;
55 }
56
57 size = PAGE_ALIGN(size);
58
59 q->ring = xskq_vmalloc_user(size);
60 if (!q->ring) {
61 kfree(q);
62 return NULL;
63 }
64
65 q->ring_vmalloc_size = size;
66 return q;
67 }
68
xskq_destroy(struct xsk_queue * q)69 void xskq_destroy(struct xsk_queue *q)
70 {
71 if (!q)
72 return;
73
74 vfree(q->ring);
75 kfree(q);
76 }
77