xref: /xnu-12377.81.4/osfmk/arm/io_map.c (revision 043036a2b3718f7f0be807e2870f8f47d3fa0796)
1 /*
2  * Copyright (c) 2007 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
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15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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27  */
28 /*
29  * @OSF_COPYRIGHT@
30  */
31 /*
32  * Mach Operating System Copyright (c) 1991,1990 Carnegie Mellon University
33  * All Rights Reserved.
34  *
35  * Permission to use, copy, modify and distribute this software and its
36  * documentation is hereby granted, provided that both the copyright notice
37  * and this permission notice appear in all copies of the software,
38  * derivative works or modified versions, and any portions thereof, and that
39  * both notices appear in supporting documentation.
40  *
41  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION.
42  * CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES
43  * WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
44  *
45  * Carnegie Mellon requests users of this software to return to
46  *
47  * Software Distribution Coordinator  or  [email protected]
48  * School of Computer Science Carnegie Mellon University Pittsburgh PA
49  * 15213-3890
50  *
51  * any improvements or extensions that they make and grant Carnegie Mellon the
52  * rights to redistribute these changes.
53  */
54 
55 #include <mach/vm_param.h>
56 #include <vm/vm_kern_xnu.h>
57 #include <vm/vm_map_xnu.h>
58 #include <arm/pmap.h>
59 #include <san/kasan.h>
60 
61 extern vm_offset_t virtual_space_start;     /* Next available kernel VA */
62 
63 #define IO_MAP_SIZE            (8ul << 20)
64 
65 __startup_data static struct mach_vm_range io_range;
66 static SECURITY_READ_ONLY_LATE(vm_map_t) io_submap;
67 KMEM_RANGE_REGISTER_STATIC(io_submap, &io_range, IO_MAP_SIZE);
68 
69 __startup_func
70 static void
io_map_init(void)71 io_map_init(void)
72 {
73 	vm_map_will_allocate_early_map(&io_submap);
74 	io_submap = kmem_suballoc(kernel_map, &io_range.min_address, IO_MAP_SIZE,
75 	    VM_MAP_CREATE_NEVER_FAULTS | VM_MAP_CREATE_DISABLE_HOLELIST,
76 	    VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE, KMS_PERMANENT | KMS_NOFAIL,
77 	    VM_KERN_MEMORY_IOKIT).kmr_submap;
78 }
79 #ifndef __BUILDING_XNU_LIB_UNITTEST__ /* io map is not supported in unit-tests */
80 STARTUP(KMEM, STARTUP_RANK_LAST, io_map_init);
81 #endif /* __BUILDING_XNU_LIB_UNITTEST__ */
82 
83 /*
84  * Allocate and map memory for devices that may need to be mapped before
85  * Mach VM is running. Allows caller to specify mapping protection
86  */
87 vm_offset_t
io_map(vm_map_offset_t phys_addr,vm_size_t size,unsigned int flags,vm_prot_t prot,bool unmappable)88 io_map(
89 	vm_map_offset_t         phys_addr,
90 	vm_size_t               size,
91 	unsigned int            flags,
92 	vm_prot_t               prot,
93 	bool                    unmappable)
94 {
95 	vm_offset_t start_offset = phys_addr - trunc_page(phys_addr);
96 	vm_offset_t alloc_size   = round_page(size + start_offset);
97 	vm_offset_t start;
98 
99 	phys_addr = trunc_page(phys_addr);
100 	if (startup_phase < STARTUP_SUB_KMEM) {
101 		/*
102 		 * VM is not initialized.  Grab memory.
103 		 *
104 		 * We need to steal address space, not physical memory.  Force
105 		 * alignment of virtual_space_start to support this... but be
106 		 * aware that if it is not already aligned we waste any
107 		 * trailing memory in the last page that was stolen.
108 		 */
109 		virtual_space_start = round_page(virtual_space_start);
110 
111 		start = virtual_space_start;
112 		virtual_space_start += round_page(size);
113 
114 		assert(flags == VM_WIMG_WCOMB || flags == VM_WIMG_IO);
115 
116 		if (flags == VM_WIMG_WCOMB) {
117 			pmap_map_bd_with_options(start, phys_addr,
118 			    phys_addr + alloc_size, prot, PMAP_MAP_BD_WCOMB);
119 		} else {
120 			pmap_map_bd(start, phys_addr, phys_addr + alloc_size, prot);
121 		}
122 #if KASAN
123 		kasan_notify_address(start + start_offset, size);
124 #endif
125 	} else {
126 		kma_flags_t kmaflags = KMA_NOFAIL | KMA_PAGEABLE;
127 
128 		if (unmappable) {
129 			kmaflags |= KMA_DATA_SHARED;
130 		} else {
131 			kmaflags |= KMA_PERMANENT;
132 		}
133 
134 		kmem_alloc(unmappable ? kernel_map : io_submap,
135 		    &start, alloc_size, kmaflags, VM_KERN_MEMORY_IOKIT);
136 		pmap_map(start, phys_addr, phys_addr + alloc_size, prot, flags);
137 	}
138 	return start + start_offset;
139 }
140