1 /* 2 * Copyright (c) 2015-2020 François Tigeot <ftigeot@wolfpond.org> 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 unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #ifndef _LINUX_IOMAPPING_H_ 28 #define _LINUX_IOMAPPING_H_ 29 30 #include <linux/types.h> 31 #include <linux/slab.h> 32 #include <linux/bug.h> 33 #include <linux/io.h> 34 #include <asm/page.h> 35 36 #include <asm/iomap.h> 37 38 struct io_mapping { 39 resource_size_t base; 40 unsigned long size; 41 unsigned long prot; 42 void *vaddr; 43 }; 44 45 static inline struct io_mapping * 46 io_mapping_create_wc(resource_size_t base, unsigned long size) 47 { 48 struct io_mapping *map; 49 50 map = kmalloc(sizeof(struct io_mapping), M_DRM, M_WAITOK); 51 map->base = base; 52 map->size = size; 53 map->prot = VM_MEMATTR_WRITE_COMBINING; 54 55 map->vaddr = pmap_mapdev_attr(base, size, 56 VM_MEMATTR_WRITE_COMBINING); 57 if (map->vaddr == NULL) 58 return NULL; 59 60 return map; 61 } 62 63 static inline void io_mapping_free(struct io_mapping *mapping) 64 { 65 /* Default memory attribute is write-back */ 66 pmap_mapdev_attr(mapping->base, mapping->size, VM_MEMATTR_WRITE_BACK); 67 kfree(mapping); 68 } 69 70 static inline void * 71 io_mapping_map_wc(struct io_mapping *mapping, 72 unsigned long offset, 73 unsigned long size) 74 { 75 BUG_ON(offset >= mapping->size); 76 77 return ioremap_wc(mapping->base + offset, size); 78 } 79 80 static inline void * 81 io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) 82 { 83 return ioremap_wc(mapping->base + offset, PAGE_SIZE); 84 } 85 86 static inline void 87 io_mapping_unmap(void *vaddr) 88 { 89 iounmap(vaddr); 90 } 91 92 static inline void 93 io_mapping_unmap_atomic(void *vaddr) 94 { 95 iounmap(vaddr); 96 } 97 98 static inline struct io_mapping * 99 io_mapping_init_wc(struct io_mapping *iomap, 100 resource_size_t base, 101 unsigned long size) 102 { 103 iomap->base = base; 104 iomap->size = size; 105 iomap->vaddr = ioremap_wc(base, size); 106 iomap->prot = pgprot_writecombine(PAGE_KERNEL_IO); 107 108 return iomap; 109 } 110 111 static inline void 112 io_mapping_fini(struct io_mapping *mapping) 113 { 114 iounmap(mapping->vaddr); 115 } 116 117 #endif /* _LINUX_IOMAPPING_H_ */ 118