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/malloc.h>
43 #include <vm/vm_extern.h>
44 #include <vm/vm_kern.h>
48 * We manage buffer zones up to a page in size. Buffers larger than a page can
49 * be managed by one of the kernel's page-oriented memory allocation routines as
50 * efficiently as what we can do here. Also, a page is the largest size for
51 * which we can g'tee contiguity when using uma, and contiguity is one of the
52 * requirements we have to fulfill.
54 #define MIN_ZONE_BUFSIZE 32
55 #define MAX_ZONE_BUFSIZE PAGE_SIZE
58 * The static array of 12 bufzones is big enough to handle all the zones for the
59 * smallest supported allocation size of 32 through the largest supported page
60 * size of 64K. If you up the biggest page size number, up the array size too.
61 * Basically the size of the array needs to be log2(maxsize)-log2(minsize)+1,
62 * but I don't know of an easy way to express that as a compile-time constant.
65 #error Unsupported page size
68 struct busdma_bufalloc {
71 struct busdma_bufzone buf_zones[12];
75 busdma_bufalloc_create(const char *name, bus_size_t minimum_alignment,
76 uma_alloc alloc_func, uma_free free_func, u_int32_t zcreate_flags)
78 struct busdma_bufalloc *ba;
79 struct busdma_bufzone *bz;
83 ba = malloc(sizeof(struct busdma_bufalloc), M_DEVBUF,
86 ba->min_size = MAX(MIN_ZONE_BUFSIZE, minimum_alignment);
89 * Each uma zone is created with an alignment of size-1, meaning that
90 * the alignment is equal to the size (I.E., 64 byte buffers are aligned
91 * to 64 byte boundaries, etc). This allows for a fast efficient test
92 * when deciding whether a pool buffer meets the constraints of a given
93 * tag used for allocation: the buffer is usable if tag->alignment <=
96 for (i = 0, bz = ba->buf_zones, cursize = ba->min_size;
97 i < nitems(ba->buf_zones) && cursize <= MAX_ZONE_BUFSIZE;
98 ++i, ++bz, cursize <<= 1) {
99 snprintf(bz->name, sizeof(bz->name), "dma %.10s %ju",
100 name, (uintmax_t)cursize);
102 bz->umazone = uma_zcreate(bz->name, bz->size,
103 NULL, NULL, NULL, NULL, bz->size - 1, zcreate_flags);
104 if (bz->umazone == NULL) {
105 busdma_bufalloc_destroy(ba);
108 if (alloc_func != NULL)
109 uma_zone_set_allocf(bz->umazone, alloc_func);
110 if (free_func != NULL)
111 uma_zone_set_freef(bz->umazone, free_func);
119 busdma_bufalloc_destroy(busdma_bufalloc_t ba)
121 struct busdma_bufzone *bz;
127 for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
128 uma_zdestroy(bz->umazone);
134 struct busdma_bufzone *
135 busdma_bufalloc_findzone(busdma_bufalloc_t ba, bus_size_t size)
137 struct busdma_bufzone *bz;
140 if (size > MAX_ZONE_BUFSIZE)
143 for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
144 if (bz->size >= size)
148 panic("Didn't find a buffer zone of the right size");
152 busdma_bufalloc_alloc_uncacheable(uma_zone_t zone, vm_size_t size,
153 uint8_t *pflag, int wait)
155 #ifdef VM_MEMATTR_UNCACHEABLE
157 /* Inform UMA that this allocator uses kernel_arena/object. */
158 *pflag = UMA_SLAB_KERNEL;
160 return ((void *)kmem_alloc_attr(kernel_arena, size, wait, 0,
161 BUS_SPACE_MAXADDR, VM_MEMATTR_UNCACHEABLE));
165 panic("VM_MEMATTR_UNCACHEABLE unavailable");
167 #endif /* VM_MEMATTR_UNCACHEABLE */
171 busdma_bufalloc_free_uncacheable(void *item, vm_size_t size, uint8_t pflag)
174 kmem_free(kernel_arena, (vm_offset_t)item, size);