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 66 struct busdma_bufalloc { 67 bus_size_t min_size; 68 size_t num_zones; 69 struct busdma_bufzone buf_zones[12]; 70 }; 71 72 busdma_bufalloc_t 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) 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 } 115 116 void 117 busdma_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 } 131 132 struct busdma_bufzone * 133 busdma_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 } 148 149 void * 150 busdma_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 } 167 168 void 169 busdma_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