xref: /netbsd-src/sys/dev/fdt/fdt_memory.c (revision dd3ee07da436799d8de85f3055253118b76bf345)
1 /* $NetBSD: fdt_memory.c,v 1.4 2022/01/07 07:25:37 mlelstv Exp $ */
2 
3 /*-
4  * Copyright (c) 2018 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jared McNeill <jmcneill@invisible.ca>.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include "opt_fdt.h"
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: fdt_memory.c,v 1.4 2022/01/07 07:25:37 mlelstv Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/queue.h>
39 
40 #include <libfdt.h>
41 #include <dev/fdt/fdtvar.h>
42 #include <dev/fdt/fdt_memory.h>
43 
44 #ifndef FDT_MEMORY_RANGES
45 #define FDT_MEMORY_RANGES	256
46 #endif
47 
48 struct fdt_memory_range {
49 	struct fdt_memory               mr_mem;
50 	bool                            mr_used;
51 	TAILQ_ENTRY(fdt_memory_range)   mr_list;
52 };
53 
54 static TAILQ_HEAD(fdt_memory_rangehead, fdt_memory_range) fdt_memory_ranges =
55     TAILQ_HEAD_INITIALIZER(fdt_memory_ranges);
56 
57 static struct fdt_memory_range fdt_memory_range_pool[FDT_MEMORY_RANGES];
58 
59 static struct fdt_memory_range *
60 fdt_memory_range_alloc(void)
61 {
62 	for (size_t n = 0; n < FDT_MEMORY_RANGES; n++)
63 		if (!fdt_memory_range_pool[n].mr_used) {
64 			fdt_memory_range_pool[n].mr_used = true;
65 			return &fdt_memory_range_pool[n];
66 		}
67 
68 	printf("%s: no free memory ranges, increase FDT_MEMORY_RANGES!\n", __func__);
69 	return NULL;
70 }
71 
72 static void
73 fdt_memory_range_free(struct fdt_memory_range *mr)
74 {
75 	mr->mr_used = false;
76 }
77 
78 /*
79  * Get all of physical memory, including holes.
80  */
81 void
82 fdt_memory_get(uint64_t *pstart, uint64_t *pend)
83 {
84 	const int memory = OF_finddevice("/memory");
85 	uint64_t cur_addr, cur_size;
86 	int index;
87 
88 	for (index = 0;
89 	     fdtbus_get_reg64(memory, index, &cur_addr, &cur_size) == 0;
90 	     index++) {
91 		fdt_memory_add_range(cur_addr, cur_size);
92 
93 		if (index == 0) {
94 			*pstart = cur_addr;
95 			*pend = cur_addr + cur_size;
96 			continue;
97 		}
98 		if (cur_addr < *pstart)
99 			*pstart = cur_addr;
100 		if (cur_addr + cur_size > *pend)
101 			*pend = cur_addr + cur_size;
102 	}
103 	if (index == 0)
104 		panic("Cannot determine memory size");
105 }
106 
107 /*
108  * Exclude memory ranges from memory config from the device tree
109  */
110 void
111 fdt_memory_remove_reserved(uint64_t min_addr, uint64_t max_addr)
112 {
113 	uint64_t lstart = 0, lend = 0;
114 	int index, error, phandle, child;
115 
116 	const int num = fdt_num_mem_rsv(fdtbus_get_data());
117 	for (index = 0; index <= num; index++) {
118 		uint64_t addr, size;
119 
120 		error = fdt_get_mem_rsv(fdtbus_get_data(), index,
121 		    &addr, &size);
122 		if (error != 0)
123 			continue;
124 		if (lstart <= addr && addr <= lend) {
125 			size -= (lend - addr);
126 			addr = lend;
127 		}
128 		if (size == 0)
129 			continue;
130 		if (addr + size <= min_addr)
131 			continue;
132 		if (addr >= max_addr)
133 			continue;
134 		if (addr < min_addr) {
135 			size -= (min_addr - addr);
136 			addr = min_addr;
137 		}
138 		if (addr + size > max_addr)
139 			size = max_addr - addr;
140 		fdt_memory_remove_range(addr, size);
141 		lstart = addr;
142 		lend = addr + size;
143 	}
144 
145 	/*
146 	 * "no-map" ranges defined in the /reserved-memory node
147 	 * must also be excluded.
148 	 */
149 	phandle = OF_finddevice("/reserved-memory");
150 	if (phandle != -1) {
151 		for (child = OF_child(phandle); child; child = OF_peer(child)) {
152 			bus_addr_t addr;
153 			bus_size_t size;
154 
155 			if (!of_hasprop(child, "no-map"))
156 				continue;
157 
158 			if (fdtbus_get_reg(child, 0, &addr, &size) != 0)
159 				continue;
160 			if (size == 0)
161 				continue;
162 			fdt_memory_remove_range(addr, size);
163 		}
164 	}
165 }
166 
167 void
168 fdt_memory_add_range(uint64_t start, uint64_t size)
169 {
170 	struct fdt_memory_range *mr, *prev, *cur, *tmp;
171 	bool inserted = false;
172 
173 	mr = fdt_memory_range_alloc();
174 	if (mr == NULL)
175 		return;
176 
177 	mr->mr_mem.start = start;
178 	mr->mr_mem.end = start + size;
179 
180 	/*
181 	 * Add the new range to the list of sorted ranges.
182 	 */
183 	TAILQ_FOREACH(cur, &fdt_memory_ranges, mr_list)
184 		if (mr->mr_mem.start <= cur->mr_mem.start) {
185 			TAILQ_INSERT_BEFORE(cur, mr, mr_list);
186 			inserted = true;
187 			break;
188 		}
189 	if (!inserted)
190 		TAILQ_INSERT_TAIL(&fdt_memory_ranges, mr, mr_list);
191 
192 	/*
193 	 * Remove overlaps.
194 	 */
195 	TAILQ_FOREACH_SAFE(mr, &fdt_memory_ranges, mr_list, tmp) {
196 		prev = TAILQ_PREV(mr, fdt_memory_rangehead, mr_list);
197 		if (prev && prev->mr_mem.end > mr->mr_mem.start) {
198 			mr->mr_mem.start = prev->mr_mem.end;
199 			if (mr->mr_mem.start >= mr->mr_mem.end) {
200 				TAILQ_REMOVE(&fdt_memory_ranges, mr, mr_list);
201 				fdt_memory_range_free(mr);
202 			}
203 		}
204 	}
205 
206 	/*
207 	 * Combine adjacent ranges.
208 	 */
209 	TAILQ_FOREACH_SAFE(mr, &fdt_memory_ranges, mr_list, tmp) {
210 		prev = TAILQ_PREV(mr, fdt_memory_rangehead, mr_list);
211 		if (prev && prev->mr_mem.end == mr->mr_mem.start) {
212 			prev->mr_mem.end = mr->mr_mem.end;
213 			TAILQ_REMOVE(&fdt_memory_ranges, mr, mr_list);
214 			fdt_memory_range_free(mr);
215 		}
216 	}
217 }
218 
219 void
220 fdt_memory_remove_range(uint64_t start, uint64_t size)
221 {
222 	struct fdt_memory_range *mr, *next, *tmp;
223 	const uint64_t end = start + size;
224 
225 	TAILQ_FOREACH_SAFE(mr, &fdt_memory_ranges, mr_list, tmp) {
226 		if (start <= mr->mr_mem.start && end >= mr->mr_mem.end) {
227 			/*
228 			 * Removed range completely covers this range,
229 			 * just remove it.
230 			 */
231 			TAILQ_REMOVE(&fdt_memory_ranges, mr, mr_list);
232 			fdt_memory_range_free(mr);
233 		} else if (start > mr->mr_mem.start && end < mr->mr_mem.end) {
234 			/*
235 			 * Removed range is completely contained by this range,
236 			 * split it.
237 			 */
238 			next = fdt_memory_range_alloc();
239 			if (next == NULL)
240 				panic("fdt_memory_remove_range");
241 			next->mr_mem.start = end;
242 			next->mr_mem.end = mr->mr_mem.end;
243 			mr->mr_mem.end = start;
244 			TAILQ_INSERT_AFTER(&fdt_memory_ranges, mr, next, mr_list);
245 		} else if (start <= mr->mr_mem.start && end > mr->mr_mem.start && end < mr->mr_mem.end) {
246 			/*
247 			 * Partial overlap at the beginning of the range.
248 			 */
249 			mr->mr_mem.start = end;
250 		} else if (start > mr->mr_mem.start && start < mr->mr_mem.end && end >= mr->mr_mem.end) {
251 			/*
252 			 * Partial overlap at the end of the range.
253 			 */
254 			mr->mr_mem.end = start;
255 		}
256 		KASSERT(mr->mr_mem.start < mr->mr_mem.end);
257 	}
258 }
259 
260 void
261 fdt_memory_foreach(void (*fn)(const struct fdt_memory *, void *), void *arg)
262 {
263 	struct fdt_memory_range *mr;
264 
265 	TAILQ_FOREACH(mr, &fdt_memory_ranges, mr_list)
266 		fn(&mr->mr_mem, arg);
267 }
268