2 * Copyright (c) 2012 Ian Lepore
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 * Buffer allocation support routines for bus_dmamem_alloc implementations.
34 #include <sys/param.h>
35 #include <sys/systm.h>
37 #include <sys/busdma_bufalloc.h>
38 #include <sys/malloc.h>
41 #include <vm/vm_extern.h>
42 #include <vm/vm_kern.h>
46 * We manage buffer zones up to a page in size. Buffers larger than a page can
47 * be managed by one of the kernel's page-oriented memory allocation routines as
48 * efficiently as what we can do here. Also, a page is the largest size for
49 * which we can g'tee contiguity when using uma, and contiguity is one of the
50 * requirements we have to fulfill.
52 #define MIN_ZONE_BUFSIZE 32
53 #define MAX_ZONE_BUFSIZE PAGE_SIZE
56 * The static array of 12 bufzones is big enough to handle all the zones for the
57 * smallest supported allocation size of 32 through the largest supported page
58 * size of 64K. If you up the biggest page size number, up the array size too.
59 * Basically the size of the array needs to be log2(maxsize)-log2(minsize)+1,
60 * but I don't know of an easy way to express that as a compile-time constant.
63 #error Unsupported page size
66 struct busdma_bufalloc {
69 struct busdma_bufzone buf_zones[12];
73 busdma_bufalloc_create(const char *name, bus_size_t minimum_alignment,
74 uma_alloc alloc_func, uma_free free_func, u_int32_t zcreate_flags)
76 struct busdma_bufalloc *ba;
77 struct busdma_bufzone *bz;
81 ba = malloc(sizeof(struct busdma_bufalloc), M_DEVBUF,
84 ba->min_size = MAX(MIN_ZONE_BUFSIZE, minimum_alignment);
87 * Each uma zone is created with an alignment of size-1, meaning that
88 * the alignment is equal to the size (I.E., 64 byte buffers are aligned
89 * to 64 byte boundaries, etc). This allows for a fast efficient test
90 * when deciding whether a pool buffer meets the constraints of a given
91 * tag used for allocation: the buffer is usable if tag->alignment <=
94 for (i = 0, bz = ba->buf_zones, cursize = ba->min_size;
95 i < nitems(ba->buf_zones) && cursize <= MAX_ZONE_BUFSIZE;
96 ++i, ++bz, cursize <<= 1) {
97 snprintf(bz->name, sizeof(bz->name), "dma %.10s %lu",
100 bz->umazone = uma_zcreate(bz->name, bz->size,
101 NULL, NULL, NULL, NULL, bz->size - 1, zcreate_flags);
102 if (bz->umazone == NULL) {
103 busdma_bufalloc_destroy(ba);
106 if (alloc_func != NULL)
107 uma_zone_set_allocf(bz->umazone, alloc_func);
108 if (free_func != NULL)
109 uma_zone_set_freef(bz->umazone, free_func);
117 busdma_bufalloc_destroy(busdma_bufalloc_t ba)
119 struct busdma_bufzone *bz;
125 for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
126 uma_zdestroy(bz->umazone);
132 struct busdma_bufzone *
133 busdma_bufalloc_findzone(busdma_bufalloc_t ba, bus_size_t size)
135 struct busdma_bufzone *bz;
138 if (size > MAX_ZONE_BUFSIZE)
141 for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
142 if (bz->size >= size)
146 panic("Didn't find a buffer zone of the right size");
150 busdma_bufalloc_alloc_uncacheable(uma_zone_t zone, int size, u_int8_t *pflag,
153 #ifdef VM_MEMATTR_UNCACHEABLE
155 /* Inform UMA that this allocator uses kernel_arena/object. */
156 *pflag = UMA_SLAB_KERNEL;
158 return ((void *)kmem_alloc_attr(kernel_arena, size, wait, 0,
159 BUS_SPACE_MAXADDR, VM_MEMATTR_UNCACHEABLE));
163 panic("VM_MEMATTR_UNCACHEABLE unavailable");
165 #endif /* VM_MEMATTR_UNCACHEABLE */
169 busdma_bufalloc_free_uncacheable(void *item, int size, u_int8_t pflag)
172 kmem_free(kernel_arena, (vm_offset_t)item, size);