xref: /freebsd/sys/dev/netmap/netmap_mem2.h (revision 96190b4fef3b4a0cc3ca0606b0c4e3e69a5e6717)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (C) 2012-2014 Matteo Landi
5  * Copyright (C) 2012-2016 Luigi Rizzo
6  * Copyright (C) 2012-2016 Giuseppe Lettieri
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *   1. Redistributions of source code must retain the above copyright
13  *      notice, this list of conditions and the following disclaimer.
14  *   2. Redistributions in binary form must reproduce the above copyright
15  *      notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  *
33  * (New) memory allocator for netmap
34  */
35 
36 /*
37  * This allocator creates three memory pools:
38  *	nm_if_pool	for the struct netmap_if
39  *	nm_ring_pool	for the struct netmap_ring
40  *	nm_buf_pool	for the packet buffers.
41  *
42  * that contain netmap objects. Each pool is made of a number of clusters,
43  * multiple of a page size, each containing an integer number of objects.
44  * The clusters are contiguous in user space but not in the kernel.
45  * Only nm_buf_pool needs to be dma-able,
46  * but for convenience use the same type of allocator for all.
47  *
48  * Once mapped, the three pools are exported to userspace
49  * as a contiguous block, starting from nm_if_pool. Each
50  * cluster (and pool) is an integral number of pages.
51  *   [ . . . ][ . . . . . .][ . . . . . . . . . .]
52  *    nm_if     nm_ring            nm_buf
53  *
54  * The userspace areas contain offsets of the objects in userspace.
55  * When (at init time) we write these offsets, we find out the index
56  * of the object, and from there locate the offset from the beginning
57  * of the region.
58  *
59  * The individual allocators manage a pool of memory for objects of
60  * the same size.
61  * The pool is split into smaller clusters, whose size is a
62  * multiple of the page size. The cluster size is chosen
63  * to minimize the waste for a given max cluster size
64  * (we do it by brute force, as we have relatively few objects
65  * per cluster).
66  *
67  * Objects are aligned to the cache line (64 bytes) rounding up object
68  * sizes when needed. A bitmap contains the state of each object.
69  * Allocation scans the bitmap; this is done only on attach, so we are not
70  * too worried about performance
71  *
72  * For each allocator we can define (through sysctl) the size and
73  * number of each object. Memory is allocated at the first use of a
74  * netmap file descriptor, and can be freed when all such descriptors
75  * have been released (including unmapping the memory).
76  * If memory is scarce, the system tries to get as much as possible
77  * and the sysctl values reflect the actual allocation.
78  * Together with desired values, the sysctl export also absolute
79  * min and maximum values that cannot be overridden.
80  *
81  * struct netmap_if:
82  *	variable size, max 16 bytes per ring pair plus some fixed amount.
83  *	1024 bytes should be large enough in practice.
84  *
85  *	In the worst case we have one netmap_if per ring in the system.
86  *
87  * struct netmap_ring
88  *	variable size, 8 byte per slot plus some fixed amount.
89  *	Rings can be large (e.g. 4k slots, or >32Kbytes).
90  *	We default to 36 KB (9 pages), and a few hundred rings.
91  *
92  * struct netmap_buffer
93  *	The more the better, both because fast interfaces tend to have
94  *	many slots, and because we may want to use buffers to store
95  *	packets in userspace avoiding copies.
96  *	Must contain a full frame (eg 1518, or more for vlans, jumbo
97  *	frames etc.) plus be nicely aligned, plus some NICs restrict
98  *	the size to multiple of 1K or so. Default to 2K
99  */
100 #ifndef _NET_NETMAP_MEM2_H_
101 #define _NET_NETMAP_MEM2_H_
102 
103 
104 
105 /* We implement two kinds of netmap_mem_d structures:
106  *
107  * - global: used by hardware NICS;
108  *
109  * - private: used by VALE ports.
110  *
111  * In both cases, the netmap_mem_d structure has the same lifetime as the
112  * netmap_adapter of the corresponding NIC or port. It is the responsibility of
113  * the client code to delete the private allocator when the associated
114  * netmap_adapter is freed (this is implemented by the NAF_MEM_OWNER flag in
115  * netmap.c).  The 'refcount' field counts the number of active users of the
116  * structure. The global allocator uses this information to prevent/allow
117  * reconfiguration. The private allocators release all their memory when there
118  * are no active users.  By 'active user' we mean an existing netmap_priv
119  * structure holding a reference to the allocator.
120  */
121 
122 extern struct netmap_mem_d nm_mem;
123 typedef uint16_t nm_memid_t;
124 
125 int	   netmap_mem_get_lut(struct netmap_mem_d *, struct netmap_lut *);
126 nm_memid_t netmap_mem_get_id(struct netmap_mem_d *);
127 vm_paddr_t netmap_mem_ofstophys(struct netmap_mem_d *, vm_ooffset_t);
128 #ifdef _WIN32
129 PMDL win32_build_user_vm_map(struct netmap_mem_d* nmd);
130 #endif
131 int	   netmap_mem_finalize(struct netmap_mem_d *, struct netmap_adapter *);
132 int 	   netmap_mem_init(void);
133 void 	   netmap_mem_fini(void);
134 struct netmap_if * netmap_mem_if_new(struct netmap_adapter *, struct netmap_priv_d *);
135 void 	   netmap_mem_if_delete(struct netmap_adapter *, struct netmap_if *);
136 int	   netmap_mem_rings_create(struct netmap_adapter *);
137 void	   netmap_mem_rings_delete(struct netmap_adapter *);
138 int 	   netmap_mem_deref(struct netmap_mem_d *, struct netmap_adapter *);
139 int	   netmap_mem2_get_pool_info(struct netmap_mem_d *, u_int, u_int *, u_int *);
140 int	   netmap_mem_get_info(struct netmap_mem_d *, uint64_t *size,
141 				u_int *memflags, nm_memid_t *id);
142 ssize_t    netmap_mem_if_offset(struct netmap_mem_d *, const void *vaddr);
143 struct netmap_mem_d* netmap_mem_private_new( u_int txr, u_int txd, u_int rxr, u_int rxd,
144 		u_int extra_bufs, u_int npipes, int* error);
145 
146 #define netmap_mem_get(d) __netmap_mem_get(d, __FUNCTION__, __LINE__)
147 #define netmap_mem_put(d) __netmap_mem_put(d, __FUNCTION__, __LINE__)
148 struct netmap_mem_d* __netmap_mem_get(struct netmap_mem_d *, const char *, int);
149 struct netmap_mem_d* netmap_mem_get_allocator(struct netmap_adapter *);
150 void __netmap_mem_put(struct netmap_mem_d *, const char *, int);
151 struct netmap_mem_d* netmap_mem_find(nm_memid_t);
152 unsigned netmap_mem_bufsize(struct netmap_mem_d *nmd);
153 
154 #ifdef WITH_EXTMEM
155 struct netmap_mem_d* netmap_mem_ext_create(uint64_t, struct nmreq_pools_info *, int *);
156 #else /* !WITH_EXTMEM */
157 #define netmap_mem_ext_create(nmr, _perr) \
158 	({ int *perr = _perr; if (perr) *(perr) = EOPNOTSUPP; NULL; })
159 #endif /* WITH_EXTMEM */
160 
161 #ifdef WITH_PTNETMAP
162 struct netmap_mem_d* netmap_mem_pt_guest_new(if_t,
163 					     unsigned int nifp_offset,
164 					     unsigned int memid);
165 struct ptnetmap_memdev;
166 struct netmap_mem_d* netmap_mem_pt_guest_attach(struct ptnetmap_memdev *, uint16_t);
167 int netmap_mem_pt_guest_ifp_del(struct netmap_mem_d *, if_t);
168 #endif /* WITH_PTNETMAP */
169 
170 int netmap_mem_pools_info_get(struct nmreq_pools_info *,
171 				struct netmap_mem_d *);
172 
173 #define NETMAP_MEM_PRIVATE	0x2	/* allocator uses private address space */
174 #define NETMAP_MEM_IO		0x4	/* the underlying memory is mmapped I/O */
175 
176 uint32_t netmap_extra_alloc(struct netmap_adapter *, uint32_t *, uint32_t n);
177 
178 #ifdef WITH_EXTMEM
179 #include <net/netmap_virt.h>
180 struct nm_os_extmem; /* opaque */
181 struct nm_os_extmem *nm_os_extmem_create(unsigned long, struct nmreq_pools_info *, int *perror);
182 char *nm_os_extmem_nextpage(struct nm_os_extmem *);
183 int nm_os_extmem_nr_pages(struct nm_os_extmem *);
184 int nm_os_extmem_isequal(struct nm_os_extmem *, struct nm_os_extmem *);
185 void nm_os_extmem_delete(struct nm_os_extmem *);
186 #endif /* WITH_EXTMEM */
187 
188 #endif
189