2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2012 Ian Lepore
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
33 * Buffer allocation support routines for bus_dmamem_alloc implementations.
36 #include <sys/param.h>
37 #include <sys/systm.h>
39 #include <sys/busdma_bufalloc.h>
40 #include <sys/domainset.h>
41 #include <sys/malloc.h>
44 #include <vm/vm_extern.h>
45 #include <vm/vm_kern.h>
49 * We manage buffer zones up to a page in size. Buffers larger than a page can
50 * be managed by one of the kernel's page-oriented memory allocation routines as
51 * efficiently as what we can do here. Also, a page is the largest size for
52 * which we can g'tee contiguity when using uma, and contiguity is one of the
53 * requirements we have to fulfill.
55 #define MIN_ZONE_BUFSIZE 32
56 #define MAX_ZONE_BUFSIZE PAGE_SIZE
59 * The static array of 12 bufzones is big enough to handle all the zones for the
60 * smallest supported allocation size of 32 through the largest supported page
61 * size of 64K. If you up the biggest page size number, up the array size too.
62 * Basically the size of the array needs to be log2(maxsize)-log2(minsize)+1,
63 * but I don't know of an easy way to express that as a compile-time constant.
66 #error Unsupported page size
69 struct busdma_bufalloc {
72 struct busdma_bufzone buf_zones[12];
76 busdma_bufalloc_create(const char *name, bus_size_t minimum_alignment,
77 uma_alloc alloc_func, uma_free free_func, u_int32_t zcreate_flags)
79 struct busdma_bufalloc *ba;
80 struct busdma_bufzone *bz;
84 ba = malloc(sizeof(struct busdma_bufalloc), M_DEVBUF,
87 ba->min_size = MAX(MIN_ZONE_BUFSIZE, minimum_alignment);
90 * Each uma zone is created with an alignment of size-1, meaning that
91 * the alignment is equal to the size (I.E., 64 byte buffers are aligned
92 * to 64 byte boundaries, etc). This allows for a fast efficient test
93 * when deciding whether a pool buffer meets the constraints of a given
94 * tag used for allocation: the buffer is usable if tag->alignment <=
97 for (i = 0, bz = ba->buf_zones, cursize = ba->min_size;
98 i < nitems(ba->buf_zones) && cursize <= MAX_ZONE_BUFSIZE;
99 ++i, ++bz, cursize <<= 1) {
100 snprintf(bz->name, sizeof(bz->name), "dma %.10s %ju",
101 name, (uintmax_t)cursize);
103 bz->umazone = uma_zcreate(bz->name, bz->size,
104 NULL, NULL, NULL, NULL, bz->size - 1, zcreate_flags);
105 if (bz->umazone == NULL) {
106 busdma_bufalloc_destroy(ba);
109 if (alloc_func != NULL)
110 uma_zone_set_allocf(bz->umazone, alloc_func);
111 if (free_func != NULL)
112 uma_zone_set_freef(bz->umazone, free_func);
120 busdma_bufalloc_destroy(busdma_bufalloc_t ba)
122 struct busdma_bufzone *bz;
128 for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
129 uma_zdestroy(bz->umazone);
135 struct busdma_bufzone *
136 busdma_bufalloc_findzone(busdma_bufalloc_t ba, bus_size_t size)
138 struct busdma_bufzone *bz;
141 if (size > MAX_ZONE_BUFSIZE)
144 for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
145 if (bz->size >= size)
149 panic("Didn't find a buffer zone of the right size");
153 busdma_bufalloc_alloc_uncacheable(uma_zone_t zone, vm_size_t size, int domain,
154 uint8_t *pflag, int wait)
157 #ifdef VM_MEMATTR_UNCACHEABLE
158 /* Inform UMA that this allocator uses kernel_arena/object. */
159 *pflag = UMA_SLAB_KERNEL;
161 return ((void *)kmem_alloc_attr_domainset(DOMAINSET_FIXED(domain), size,
162 wait, 0, BUS_SPACE_MAXADDR, VM_MEMATTR_UNCACHEABLE));
164 panic("VM_MEMATTR_UNCACHEABLE unavailable");
165 #endif /* VM_MEMATTR_UNCACHEABLE */
169 busdma_bufalloc_free_uncacheable(void *item, vm_size_t size, uint8_t pflag)
172 kmem_free((vm_offset_t)item, size);