1/*-
2 * Copyright (c) 2012 Ian Lepore
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30/*
31 * Buffer allocation support routines for bus_dmamem_alloc implementations.
32 */
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/bus.h>
37#include <sys/busdma_bufalloc.h>
38#include <sys/malloc.h>
39
40#include <vm/vm.h>
41#include <vm/vm_extern.h>
42#include <vm/vm_kern.h>
43#include <vm/uma.h>
44
45/*
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.
51 */
52#define	MIN_ZONE_BUFSIZE	32
53#define	MAX_ZONE_BUFSIZE	PAGE_SIZE
54
55/*
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.
61 */
62#if PAGE_SIZE > 65536
63#error Unsupported page size
64#endif
65
66struct busdma_bufalloc {
67	bus_size_t		min_size;
68	size_t			num_zones;
69	struct busdma_bufzone	buf_zones[12];
70};
71
72busdma_bufalloc_t
73busdma_bufalloc_create(const char *name, bus_size_t minimum_alignment,
74    uma_alloc alloc_func, uma_free free_func, u_int32_t zcreate_flags)
75{
76	struct busdma_bufalloc *ba;
77	struct busdma_bufzone *bz;
78	int i;
79	bus_size_t cursize;
80
81	ba = malloc(sizeof(struct busdma_bufalloc), M_DEVBUF,
82	    M_ZERO | M_WAITOK);
83
84	ba->min_size = MAX(MIN_ZONE_BUFSIZE, minimum_alignment);
85
86	/*
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 <=
92	 * bufzone->size.
93	 */
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 %ju",
98		    name, (uintmax_t)cursize);
99		bz->size = cursize;
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);
104			return (NULL);
105		}
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);
110		++ba->num_zones;
111	}
112
113	return (ba);
114}
115
116void
117busdma_bufalloc_destroy(busdma_bufalloc_t ba)
118{
119	struct busdma_bufzone *bz;
120	int i;
121
122	if (ba == NULL)
123		return;
124
125	for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
126		uma_zdestroy(bz->umazone);
127	}
128
129	free(ba, M_DEVBUF);
130}
131
132struct busdma_bufzone *
133busdma_bufalloc_findzone(busdma_bufalloc_t ba, bus_size_t size)
134{
135	struct busdma_bufzone *bz;
136	int i;
137
138	if (size > MAX_ZONE_BUFSIZE)
139		return (NULL);
140
141	for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
142		if (bz->size >= size)
143			return (bz);
144	}
145
146	panic("Didn't find a buffer zone of the right size");
147}
148
149void *
150busdma_bufalloc_alloc_uncacheable(uma_zone_t zone, vm_size_t size,
151    uint8_t *pflag, int wait)
152{
153#ifdef VM_MEMATTR_UNCACHEABLE
154
155	/* Inform UMA that this allocator uses kernel_arena/object. */
156	*pflag = UMA_SLAB_KERNEL;
157
158	return ((void *)kmem_alloc_attr(kernel_arena, size, wait, 0,
159	    BUS_SPACE_MAXADDR, VM_MEMATTR_UNCACHEABLE));
160
161#else
162
163	panic("VM_MEMATTR_UNCACHEABLE unavailable");
164
165#endif	/* VM_MEMATTR_UNCACHEABLE */
166}
167
168void
169busdma_bufalloc_free_uncacheable(void *item, vm_size_t size, uint8_t pflag)
170{
171
172	kmem_free(kernel_arena, (vm_offset_t)item, size);
173}
174
175