netmap_mem2.h revision 270252 
1/*
2 * Copyright (C) 2012-2014 Matteo Landi, Luigi Rizzo, Giuseppe Lettieri. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *   1. Redistributions of source code must retain the above copyright
8 *      notice, this list of conditions and the following disclaimer.
9 *   2. Redistributions in binary form must reproduce the above copyright
10 *      notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26/*
27 * $FreeBSD: stable/10/sys/dev/netmap/netmap_mem2.h 270252 2014-08-20 23:34:36Z luigi $
28 *
29 * (New) memory allocator for netmap
30 */
31
32/*
33 * This allocator creates three memory pools:
34 *	nm_if_pool	for the struct netmap_if
35 *	nm_ring_pool	for the struct netmap_ring
36 *	nm_buf_pool	for the packet buffers.
37 *
38 * that contain netmap objects. Each pool is made of a number of clusters,
39 * multiple of a page size, each containing an integer number of objects.
40 * The clusters are contiguous in user space but not in the kernel.
41 * Only nm_buf_pool needs to be dma-able,
42 * but for convenience use the same type of allocator for all.
43 *
44 * Once mapped, the three pools are exported to userspace
45 * as a contiguous block, starting from nm_if_pool. Each
46 * cluster (and pool) is an integral number of pages.
47 *   [ . . . ][ . . . . . .][ . . . . . . . . . .]
48 *    nm_if     nm_ring            nm_buf
49 *
50 * The userspace areas contain offsets of the objects in userspace.
51 * When (at init time) we write these offsets, we find out the index
52 * of the object, and from there locate the offset from the beginning
53 * of the region.
54 *
55 * The invididual allocators manage a pool of memory for objects of
56 * the same size.
57 * The pool is split into smaller clusters, whose size is a
58 * multiple of the page size. The cluster size is chosen
59 * to minimize the waste for a given max cluster size
60 * (we do it by brute force, as we have relatively few objects
61 * per cluster).
62 *
63 * Objects are aligned to the cache line (64 bytes) rounding up object
64 * sizes when needed. A bitmap contains the state of each object.
65 * Allocation scans the bitmap; this is done only on attach, so we are not
66 * too worried about performance
67 *
68 * For each allocator we can define (thorugh sysctl) the size and
69 * number of each object. Memory is allocated at the first use of a
70 * netmap file descriptor, and can be freed when all such descriptors
71 * have been released (including unmapping the memory).
72 * If memory is scarce, the system tries to get as much as possible
73 * and the sysctl values reflect the actual allocation.
74 * Together with desired values, the sysctl export also absolute
75 * min and maximum values that cannot be overridden.
76 *
77 * struct netmap_if:
78 *	variable size, max 16 bytes per ring pair plus some fixed amount.
79 *	1024 bytes should be large enough in practice.
80 *
81 *	In the worst case we have one netmap_if per ring in the system.
82 *
83 * struct netmap_ring
84 *	variable size, 8 byte per slot plus some fixed amount.
85 *	Rings can be large (e.g. 4k slots, or >32Kbytes).
86 *	We default to 36 KB (9 pages), and a few hundred rings.
87 *
88 * struct netmap_buffer
89 *	The more the better, both because fast interfaces tend to have
90 *	many slots, and because we may want to use buffers to store
91 *	packets in userspace avoiding copies.
92 *	Must contain a full frame (eg 1518, or more for vlans, jumbo
93 *	frames etc.) plus be nicely aligned, plus some NICs restrict
94 *	the size to multiple of 1K or so. Default to 2K
95 */
96#ifndef _NET_NETMAP_MEM2_H_
97#define _NET_NETMAP_MEM2_H_
98
99
100
101/* We implement two kinds of netmap_mem_d structures:
102 *
103 * - global: used by hardware NICS;
104 *
105 * - private: used by VALE ports.
106 *
107 * In both cases, the netmap_mem_d structure has the same lifetime as the
108 * netmap_adapter of the corresponding NIC or port. It is the responsibility of
109 * the client code to delete the private allocator when the associated
110 * netmap_adapter is freed (this is implemented by the NAF_MEM_OWNER flag in
111 * netmap.c).  The 'refcount' field counts the number of active users of the
112 * structure. The global allocator uses this information to prevent/allow
113 * reconfiguration. The private allocators release all their memory when there
114 * are no active users.  By 'active user' we mean an existing netmap_priv
115 * structure holding a reference to the allocator.
116 */
117
118extern struct netmap_mem_d nm_mem;
119
120struct lut_entry* netmap_mem_get_lut(struct netmap_mem_d *);
121u_int      netmap_mem_get_buftotal(struct netmap_mem_d *);
122size_t     netmap_mem_get_bufsize(struct netmap_mem_d *);
123vm_paddr_t netmap_mem_ofstophys(struct netmap_mem_d *, vm_ooffset_t);
124int	   netmap_mem_finalize(struct netmap_mem_d *, struct netmap_adapter *);
125int 	   netmap_mem_init(void);
126void 	   netmap_mem_fini(void);
127struct netmap_if * netmap_mem_if_new(struct netmap_adapter *);
128void 	   netmap_mem_if_delete(struct netmap_adapter *, struct netmap_if *);
129int	   netmap_mem_rings_create(struct netmap_adapter *);
130void	   netmap_mem_rings_delete(struct netmap_adapter *);
131void 	   netmap_mem_deref(struct netmap_mem_d *, struct netmap_adapter *);
132int	   netmap_mem_get_info(struct netmap_mem_d *, u_int *size, u_int *memflags, uint16_t *id);
133ssize_t    netmap_mem_if_offset(struct netmap_mem_d *, const void *vaddr);
134struct netmap_mem_d* netmap_mem_private_new(const char *name,
135	u_int txr, u_int txd, u_int rxr, u_int rxd, u_int extra_bufs, u_int npipes,
136	int* error);
137void	   netmap_mem_private_delete(struct netmap_mem_d *);
138
139#define NETMAP_MEM_PRIVATE	0x2	/* allocator uses private address space */
140#define NETMAP_MEM_IO		0x4	/* the underlying memory is mmapped I/O */
141
142uint32_t netmap_extra_alloc(struct netmap_adapter *, uint32_t *, uint32_t n);
143
144
145#endif
146