xref: /xnu-11417.121.6/osfmk/arm/io_map.c (revision a1e26a70f38d1d7daa7b49b258e2f8538ad81650)
1 /*
2  * Copyright (c) 2007 Apple Inc. All rights reserved.
3  *
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5  *
6  * This file contains Original Code and/or Modifications of Original Code
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8  * Version 2.0 (the 'License'). You may not use this file except in
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28 /*
29  * @OSF_COPYRIGHT@
30  */
31 /*
32  * Mach Operating System Copyright (c) 1991,1990 Carnegie Mellon University
33  * All Rights Reserved.
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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  *
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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 STARTUP(KMEM, STARTUP_RANK_LAST, io_map_init);
80 
81 /*
82  * Allocate and map memory for devices that may need to be mapped before
83  * Mach VM is running. Allows caller to specify mapping protection
84  */
85 vm_offset_t
io_map(vm_map_offset_t phys_addr,vm_size_t size,unsigned int flags,vm_prot_t prot,bool unmappable)86 io_map(
87 	vm_map_offset_t         phys_addr,
88 	vm_size_t               size,
89 	unsigned int            flags,
90 	vm_prot_t               prot,
91 	bool                    unmappable)
92 {
93 	vm_offset_t start_offset = phys_addr - trunc_page(phys_addr);
94 	vm_offset_t alloc_size   = round_page(size + start_offset);
95 	vm_offset_t start;
96 
97 	phys_addr = trunc_page(phys_addr);
98 	if (startup_phase < STARTUP_SUB_KMEM) {
99 		/*
100 		 * VM is not initialized.  Grab memory.
101 		 *
102 		 * We need to steal address space, not physical memory.  Force
103 		 * alignment of virtual_space_start to support this... but be
104 		 * aware that if it is not already aligned we waste any
105 		 * trailing memory in the last page that was stolen.
106 		 */
107 		virtual_space_start = round_page(virtual_space_start);
108 
109 		start = virtual_space_start;
110 		virtual_space_start += round_page(size);
111 
112 		assert(flags == VM_WIMG_WCOMB || flags == VM_WIMG_IO);
113 
114 		if (flags == VM_WIMG_WCOMB) {
115 			pmap_map_bd_with_options(start, phys_addr,
116 			    phys_addr + alloc_size, prot, PMAP_MAP_BD_WCOMB);
117 		} else {
118 			pmap_map_bd(start, phys_addr, phys_addr + alloc_size, prot);
119 		}
120 #if KASAN
121 		kasan_notify_address(start + start_offset, size);
122 #endif
123 	} else {
124 		kma_flags_t kmaflags = KMA_NOFAIL | KMA_PAGEABLE;
125 
126 		if (unmappable) {
127 			kmaflags |= KMA_DATA;
128 		} else {
129 			kmaflags |= KMA_PERMANENT;
130 		}
131 
132 		kmem_alloc(unmappable ? kernel_map : io_submap,
133 		    &start, alloc_size, kmaflags, VM_KERN_MEMORY_IOKIT);
134 		pmap_map(start, phys_addr, phys_addr + alloc_size, prot, flags);
135 	}
136 	return start + start_offset;
137 }
138