xref: /openbmc/linux/arch/xtensa/mm/init.c (revision 8585b316) 
1 /*
2  * arch/xtensa/mm/init.c
3  *
4  * Derived from MIPS, PPC.
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  *
10  * Copyright (C) 2001 - 2005 Tensilica Inc.
11  * Copyright (C) 2014 Cadence Design Systems Inc.
12  *
13  * Chris Zankel	<chris@zankel.net>
14  * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
15  * Marc Gauthier
16  * Kevin Chea
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/bootmem.h>
22 #include <linux/gfp.h>
23 #include <linux/swap.h>
24 #include <linux/mman.h>
25 #include <linux/nodemask.h>
26 #include <linux/mm.h>
27 
28 #include <asm/bootparam.h>
29 #include <asm/page.h>
30 #include <asm/sections.h>
31 #include <asm/sysmem.h>
32 
33 struct sysmem_info sysmem __initdata;
34 
35 static void __init sysmem_dump(void)
36 {
37 	unsigned i;
38 
39 	pr_debug("Sysmem:\n");
40 	for (i = 0; i < sysmem.nr_banks; ++i)
41 		pr_debug("  0x%08lx - 0x%08lx (%ldK)\n",
42 			 sysmem.bank[i].start, sysmem.bank[i].end,
43 			 (sysmem.bank[i].end - sysmem.bank[i].start) >> 10);
44 }
45 
46 /*
47  * Find bank with maximal .start such that bank.start <= start
48  */
49 static inline struct meminfo * __init find_bank(unsigned long start)
50 {
51 	unsigned i;
52 	struct meminfo *it = NULL;
53 
54 	for (i = 0; i < sysmem.nr_banks; ++i)
55 		if (sysmem.bank[i].start <= start)
56 			it = sysmem.bank + i;
57 		else
58 			break;
59 	return it;
60 }
61 
62 /*
63  * Move all memory banks starting at 'from' to a new place at 'to',
64  * adjust nr_banks accordingly.
65  * Both 'from' and 'to' must be inside the sysmem.bank.
66  *
67  * Returns: 0 (success), -ENOMEM (not enough space in the sysmem.bank).
68  */
69 static int __init move_banks(struct meminfo *to, struct meminfo *from)
70 {
71 	unsigned n = sysmem.nr_banks - (from - sysmem.bank);
72 
73 	if (to > from && to - from + sysmem.nr_banks > SYSMEM_BANKS_MAX)
74 		return -ENOMEM;
75 	if (to != from)
76 		memmove(to, from, n * sizeof(struct meminfo));
77 	sysmem.nr_banks += to - from;
78 	return 0;
79 }
80 
81 /*
82  * Add new bank to sysmem. Resulting sysmem is the union of bytes of the
83  * original sysmem and the new bank.
84  *
85  * Returns: 0 (success), < 0 (error)
86  */
87 int __init add_sysmem_bank(unsigned long start, unsigned long end)
88 {
89 	unsigned i;
90 	struct meminfo *it = NULL;
91 	unsigned long sz;
92 	unsigned long bank_sz = 0;
93 
94 	if (start == end ||
95 	    (start < end) != (PAGE_ALIGN(start) < (end & PAGE_MASK))) {
96 		pr_warn("Ignoring small memory bank 0x%08lx size: %ld bytes\n",
97 			start, end - start);
98 		return -EINVAL;
99 	}
100 
101 	start = PAGE_ALIGN(start);
102 	end &= PAGE_MASK;
103 	sz = end - start;
104 
105 	it = find_bank(start);
106 
107 	if (it)
108 		bank_sz = it->end - it->start;
109 
110 	if (it && bank_sz >= start - it->start) {
111 		if (end - it->start > bank_sz)
112 			it->end = end;
113 		else
114 			return 0;
115 	} else {
116 		if (!it)
117 			it = sysmem.bank;
118 		else
119 			++it;
120 
121 		if (it - sysmem.bank < sysmem.nr_banks &&
122 		    it->start - start <= sz) {
123 			it->start = start;
124 			if (it->end - it->start < sz)
125 				it->end = end;
126 			else
127 				return 0;
128 		} else {
129 			if (move_banks(it + 1, it) < 0) {
130 				pr_warn("Ignoring memory bank 0x%08lx size %ld bytes\n",
131 					start, end - start);
132 				return -EINVAL;
133 			}
134 			it->start = start;
135 			it->end = end;
136 			return 0;
137 		}
138 	}
139 	sz = it->end - it->start;
140 	for (i = it + 1 - sysmem.bank; i < sysmem.nr_banks; ++i)
141 		if (sysmem.bank[i].start - it->start <= sz) {
142 			if (sz < sysmem.bank[i].end - it->start)
143 				it->end = sysmem.bank[i].end;
144 		} else {
145 			break;
146 		}
147 
148 	move_banks(it + 1, sysmem.bank + i);
149 	return 0;
150 }
151 
152 /*
153  * mem_reserve(start, end, must_exist)
154  *
155  * Reserve some memory from the memory pool.
156  * If must_exist is set and a part of the region being reserved does not exist
157  * memory map is not altered.
158  *
159  * Parameters:
160  *  start	Start of region,
161  *  end		End of region,
162  *  must_exist	Must exist in memory pool.
163  *
164  * Returns:
165  *  0 (success)
166  *  < 0 (error)
167  */
168 
169 int __init mem_reserve(unsigned long start, unsigned long end, int must_exist)
170 {
171 	struct meminfo *it;
172 	struct meminfo *rm = NULL;
173 	unsigned long sz;
174 	unsigned long bank_sz = 0;
175 
176 	start = start & PAGE_MASK;
177 	end = PAGE_ALIGN(end);
178 	sz = end - start;
179 	if (!sz)
180 		return -EINVAL;
181 
182 	it = find_bank(start);
183 
184 	if (it)
185 		bank_sz = it->end - it->start;
186 
187 	if ((!it || end - it->start > bank_sz) && must_exist) {
188 		pr_warn("mem_reserve: [0x%0lx, 0x%0lx) not in any region!\n",
189 			start, end);
190 		return -EINVAL;
191 	}
192 
193 	if (it && start - it->start < bank_sz) {
194 		if (start == it->start) {
195 			if (end - it->start < bank_sz) {
196 				it->start = end;
197 				return 0;
198 			} else {
199 				rm = it;
200 			}
201 		} else {
202 			it->end = start;
203 			if (end - it->start < bank_sz)
204 				return add_sysmem_bank(end,
205 						       it->start + bank_sz);
206 			++it;
207 		}
208 	}
209 
210 	if (!it)
211 		it = sysmem.bank;
212 
213 	for (; it < sysmem.bank + sysmem.nr_banks; ++it) {
214 		if (it->end - start <= sz) {
215 			if (!rm)
216 				rm = it;
217 		} else {
218 			if (it->start - start < sz)
219 				it->start = end;
220 			break;
221 		}
222 	}
223 
224 	if (rm)
225 		move_banks(rm, it);
226 
227 	return 0;
228 }
229 
230 
231 /*
232  * Initialize the bootmem system and give it all low memory we have available.
233  */
234 
235 void __init bootmem_init(void)
236 {
237 	unsigned long pfn;
238 	unsigned long bootmap_start, bootmap_size;
239 	int i;
240 
241 	sysmem_dump();
242 	max_low_pfn = max_pfn = 0;
243 	min_low_pfn = ~0;
244 
245 	for (i=0; i < sysmem.nr_banks; i++) {
246 		pfn = PAGE_ALIGN(sysmem.bank[i].start) >> PAGE_SHIFT;
247 		if (pfn < min_low_pfn)
248 			min_low_pfn = pfn;
249 		pfn = PAGE_ALIGN(sysmem.bank[i].end - 1) >> PAGE_SHIFT;
250 		if (pfn > max_pfn)
251 			max_pfn = pfn;
252 	}
253 
254 	if (min_low_pfn > max_pfn)
255 		panic("No memory found!\n");
256 
257 	max_low_pfn = max_pfn < MAX_MEM_PFN >> PAGE_SHIFT ?
258 		max_pfn : MAX_MEM_PFN >> PAGE_SHIFT;
259 
260 	/* Find an area to use for the bootmem bitmap. */
261 
262 	bootmap_size = bootmem_bootmap_pages(max_low_pfn - min_low_pfn);
263 	bootmap_size <<= PAGE_SHIFT;
264 	bootmap_start = ~0;
265 
266 	for (i=0; i<sysmem.nr_banks; i++)
267 		if (sysmem.bank[i].end - sysmem.bank[i].start >= bootmap_size) {
268 			bootmap_start = sysmem.bank[i].start;
269 			break;
270 		}
271 
272 	if (bootmap_start == ~0UL)
273 		panic("Cannot find %ld bytes for bootmap\n", bootmap_size);
274 
275 	/* Reserve the bootmem bitmap area */
276 
277 	mem_reserve(bootmap_start, bootmap_start + bootmap_size, 1);
278 	bootmap_size = init_bootmem_node(NODE_DATA(0),
279 					 bootmap_start >> PAGE_SHIFT,
280 					 min_low_pfn,
281 					 max_low_pfn);
282 
283 	/* Add all remaining memory pieces into the bootmem map */
284 
285 	for (i = 0; i < sysmem.nr_banks; i++) {
286 		if (sysmem.bank[i].start >> PAGE_SHIFT < max_low_pfn) {
287 			unsigned long end = min(max_low_pfn << PAGE_SHIFT,
288 						sysmem.bank[i].end);
289 			free_bootmem(sysmem.bank[i].start,
290 				     end - sysmem.bank[i].start);
291 		}
292 	}
293 
294 }
295 
296 
297 void __init zones_init(void)
298 {
299 	unsigned long zones_size[MAX_NR_ZONES];
300 	int i;
301 
302 	/* All pages are DMA-able, so we put them all in the DMA zone. */
303 
304 	zones_size[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET;
305 	for (i = 1; i < MAX_NR_ZONES; i++)
306 		zones_size[i] = 0;
307 
308 #ifdef CONFIG_HIGHMEM
309 	zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
310 #endif
311 
312 	free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
313 }
314 
315 /*
316  * Initialize memory pages.
317  */
318 
319 void __init mem_init(void)
320 {
321 	max_mapnr = max_low_pfn - ARCH_PFN_OFFSET;
322 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
323 
324 #ifdef CONFIG_HIGHMEM
325 #error HIGHGMEM not implemented in init.c
326 #endif
327 
328 	free_all_bootmem();
329 
330 	mem_init_print_info(NULL);
331 }
332 
333 #ifdef CONFIG_BLK_DEV_INITRD
334 extern int initrd_is_mapped;
335 
336 void free_initrd_mem(unsigned long start, unsigned long end)
337 {
338 	if (initrd_is_mapped)
339 		free_reserved_area((void *)start, (void *)end, -1, "initrd");
340 }
341 #endif
342 
343 void free_initmem(void)
344 {
345 	free_initmem_default(-1);
346 }
347 
348 static void __init parse_memmap_one(char *p)
349 {
350 	char *oldp;
351 	unsigned long start_at, mem_size;
352 
353 	if (!p)
354 		return;
355 
356 	oldp = p;
357 	mem_size = memparse(p, &p);
358 	if (p == oldp)
359 		return;
360 
361 	switch (*p) {
362 	case '@':
363 		start_at = memparse(p + 1, &p);
364 		add_sysmem_bank(start_at, start_at + mem_size);
365 		break;
366 
367 	case '$':
368 		start_at = memparse(p + 1, &p);
369 		mem_reserve(start_at, start_at + mem_size, 0);
370 		break;
371 
372 	case 0:
373 		mem_reserve(mem_size, 0, 0);
374 		break;
375 
376 	default:
377 		pr_warn("Unrecognized memmap syntax: %s\n", p);
378 		break;
379 	}
380 }
381 
382 static int __init parse_memmap_opt(char *str)
383 {
384 	while (str) {
385 		char *k = strchr(str, ',');
386 
387 		if (k)
388 			*k++ = 0;
389 
390 		parse_memmap_one(str);
391 		str = k;
392 	}
393 
394 	return 0;
395 }
396 early_param("memmap", parse_memmap_opt);
397