1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2012 Ian Lepore
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
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.
15 *
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
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
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/domainset.h>
39#include <sys/malloc.h>
40
41#include <vm/vm.h>
42#include <vm/vm_extern.h>
43#include <vm/vm_kern.h>
44#include <vm/uma.h>
45
46/*
47 * We manage buffer zones up to a page in size.  Buffers larger than a page can
48 * be managed by one of the kernel's page-oriented memory allocation routines as
49 * efficiently as what we can do here.  Also, a page is the largest size for
50 * which we can g'tee contiguity when using uma, and contiguity is one of the
51 * requirements we have to fulfill.
52 */
53#define	MIN_ZONE_BUFSIZE	32
54#define	MAX_ZONE_BUFSIZE	PAGE_SIZE
55
56/*
57 * The static array of 12 bufzones is big enough to handle all the zones for the
58 * smallest supported allocation size of 32 through the largest supported page
59 * size of 64K.  If you up the biggest page size number, up the array size too.
60 * Basically the size of the array needs to be log2(maxsize)-log2(minsize)+1,
61 * but I don't know of an easy way to express that as a compile-time constant.
62 */
63#if PAGE_SIZE > 65536
64#error Unsupported page size
65#endif
66
67struct busdma_bufalloc {
68	bus_size_t		min_size;
69	size_t			num_zones;
70	struct busdma_bufzone	buf_zones[12];
71};
72
73busdma_bufalloc_t
74busdma_bufalloc_create(const char *name, bus_size_t minimum_alignment,
75    uma_alloc alloc_func, uma_free free_func, uint32_t zcreate_flags)
76{
77	struct busdma_bufalloc *ba;
78	struct busdma_bufzone *bz;
79	int i;
80	bus_size_t cursize;
81
82	ba = malloc(sizeof(struct busdma_bufalloc), M_DEVBUF,
83	    M_ZERO | M_WAITOK);
84
85	ba->min_size = MAX(MIN_ZONE_BUFSIZE, minimum_alignment);
86
87	/*
88	 * Each uma zone is created with an alignment of size-1, meaning that
89	 * the alignment is equal to the size (I.E., 64 byte buffers are aligned
90	 * to 64 byte boundaries, etc).  This allows for a fast efficient test
91	 * when deciding whether a pool buffer meets the constraints of a given
92	 * tag used for allocation: the buffer is usable if tag->alignment <=
93	 * bufzone->size.
94	 */
95	for (i = 0, bz = ba->buf_zones, cursize = ba->min_size;
96	    i < nitems(ba->buf_zones) && cursize <= MAX_ZONE_BUFSIZE;
97	    ++i, ++bz, cursize <<= 1) {
98		snprintf(bz->name, sizeof(bz->name), "dma %.10s %ju",
99		    name, (uintmax_t)cursize);
100		bz->size = cursize;
101		bz->umazone = uma_zcreate(bz->name, bz->size,
102		    NULL, NULL, NULL, NULL, bz->size - 1, zcreate_flags);
103		if (alloc_func != NULL)
104			uma_zone_set_allocf(bz->umazone, alloc_func);
105		if (free_func != NULL)
106			uma_zone_set_freef(bz->umazone, free_func);
107		++ba->num_zones;
108	}
109
110	return (ba);
111}
112
113void
114busdma_bufalloc_destroy(busdma_bufalloc_t ba)
115{
116	struct busdma_bufzone *bz;
117	int i;
118
119	if (ba == NULL)
120		return;
121
122	for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
123		uma_zdestroy(bz->umazone);
124	}
125
126	free(ba, M_DEVBUF);
127}
128
129struct busdma_bufzone *
130busdma_bufalloc_findzone(busdma_bufalloc_t ba, bus_size_t size)
131{
132	struct busdma_bufzone *bz;
133	int i;
134
135	if (size > MAX_ZONE_BUFSIZE)
136		return (NULL);
137
138	for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
139		if (bz->size >= size)
140			return (bz);
141	}
142
143	panic("Didn't find a buffer zone of the right size");
144}
145
146void *
147busdma_bufalloc_alloc_uncacheable(uma_zone_t zone, vm_size_t size, int domain,
148    uint8_t *pflag, int wait)
149{
150
151#ifdef VM_MEMATTR_UNCACHEABLE
152	/* Inform UMA that this allocator uses kernel_arena/object. */
153	*pflag = UMA_SLAB_KERNEL;
154
155	return (kmem_alloc_attr_domainset(DOMAINSET_FIXED(domain), size,
156	    wait, 0, BUS_SPACE_MAXADDR, VM_MEMATTR_UNCACHEABLE));
157#else
158	panic("VM_MEMATTR_UNCACHEABLE unavailable");
159#endif	/* VM_MEMATTR_UNCACHEABLE */
160}
161
162void
163busdma_bufalloc_free_uncacheable(void *item, vm_size_t size, uint8_t pflag)
164{
165
166	kmem_free(item, size);
167}
168