xref: /openbmc/linux/arch/arm64/mm/init.c (revision 9d749629)
1 /*
2  * Based on arch/arm/mm/init.c
3  *
4  * Copyright (C) 1995-2005 Russell King
5  * Copyright (C) 2012 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/export.h>
22 #include <linux/errno.h>
23 #include <linux/swap.h>
24 #include <linux/init.h>
25 #include <linux/bootmem.h>
26 #include <linux/mman.h>
27 #include <linux/nodemask.h>
28 #include <linux/initrd.h>
29 #include <linux/gfp.h>
30 #include <linux/memblock.h>
31 #include <linux/sort.h>
32 #include <linux/of_fdt.h>
33 
34 #include <asm/prom.h>
35 #include <asm/sections.h>
36 #include <asm/setup.h>
37 #include <asm/sizes.h>
38 #include <asm/tlb.h>
39 
40 #include "mm.h"
41 
42 static unsigned long phys_initrd_start __initdata = 0;
43 static unsigned long phys_initrd_size __initdata = 0;
44 
45 phys_addr_t memstart_addr __read_mostly = 0;
46 
47 void __init early_init_dt_setup_initrd_arch(unsigned long start,
48 					    unsigned long end)
49 {
50 	phys_initrd_start = start;
51 	phys_initrd_size = end - start;
52 }
53 
54 static int __init early_initrd(char *p)
55 {
56 	unsigned long start, size;
57 	char *endp;
58 
59 	start = memparse(p, &endp);
60 	if (*endp == ',') {
61 		size = memparse(endp + 1, NULL);
62 
63 		phys_initrd_start = start;
64 		phys_initrd_size = size;
65 	}
66 	return 0;
67 }
68 early_param("initrd", early_initrd);
69 
70 #define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)
71 
72 static void __init zone_sizes_init(unsigned long min, unsigned long max)
73 {
74 	struct memblock_region *reg;
75 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
76 	unsigned long max_dma32 = min;
77 
78 	memset(zone_size, 0, sizeof(zone_size));
79 
80 #ifdef CONFIG_ZONE_DMA32
81 	/* 4GB maximum for 32-bit only capable devices */
82 	max_dma32 = max(min, min(max, MAX_DMA32_PFN));
83 	zone_size[ZONE_DMA32] = max_dma32 - min;
84 #endif
85 	zone_size[ZONE_NORMAL] = max - max_dma32;
86 
87 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
88 
89 	for_each_memblock(memory, reg) {
90 		unsigned long start = memblock_region_memory_base_pfn(reg);
91 		unsigned long end = memblock_region_memory_end_pfn(reg);
92 
93 		if (start >= max)
94 			continue;
95 #ifdef CONFIG_ZONE_DMA32
96 		if (start < max_dma32) {
97 			unsigned long dma_end = min(end, max_dma32);
98 			zhole_size[ZONE_DMA32] -= dma_end - start;
99 		}
100 #endif
101 		if (end > max_dma32) {
102 			unsigned long normal_end = min(end, max);
103 			unsigned long normal_start = max(start, max_dma32);
104 			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
105 		}
106 	}
107 
108 	free_area_init_node(0, zone_size, min, zhole_size);
109 }
110 
111 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
112 int pfn_valid(unsigned long pfn)
113 {
114 	return memblock_is_memory(pfn << PAGE_SHIFT);
115 }
116 EXPORT_SYMBOL(pfn_valid);
117 #endif
118 
119 #ifndef CONFIG_SPARSEMEM
120 static void arm64_memory_present(void)
121 {
122 }
123 #else
124 static void arm64_memory_present(void)
125 {
126 	struct memblock_region *reg;
127 
128 	for_each_memblock(memory, reg)
129 		memory_present(0, memblock_region_memory_base_pfn(reg),
130 			       memblock_region_memory_end_pfn(reg));
131 }
132 #endif
133 
134 void __init arm64_memblock_init(void)
135 {
136 	u64 *reserve_map, base, size;
137 
138 	/* Register the kernel text, kernel data and initrd with memblock */
139 	memblock_reserve(__pa(_text), _end - _text);
140 #ifdef CONFIG_BLK_DEV_INITRD
141 	if (phys_initrd_size) {
142 		memblock_reserve(phys_initrd_start, phys_initrd_size);
143 
144 		/* Now convert initrd to virtual addresses */
145 		initrd_start = __phys_to_virt(phys_initrd_start);
146 		initrd_end = initrd_start + phys_initrd_size;
147 	}
148 #endif
149 
150 	/*
151 	 * Reserve the page tables.  These are already in use,
152 	 * and can only be in node 0.
153 	 */
154 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
155 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
156 
157 	/* Reserve the dtb region */
158 	memblock_reserve(virt_to_phys(initial_boot_params),
159 			 be32_to_cpu(initial_boot_params->totalsize));
160 
161 	/*
162 	 * Process the reserve map.  This will probably overlap the initrd
163 	 * and dtb locations which are already reserved, but overlapping
164 	 * doesn't hurt anything
165 	 */
166 	reserve_map = ((void*)initial_boot_params) +
167 			be32_to_cpu(initial_boot_params->off_mem_rsvmap);
168 	while (1) {
169 		base = be64_to_cpup(reserve_map++);
170 		size = be64_to_cpup(reserve_map++);
171 		if (!size)
172 			break;
173 		memblock_reserve(base, size);
174 	}
175 
176 	memblock_allow_resize();
177 	memblock_dump_all();
178 }
179 
180 void __init bootmem_init(void)
181 {
182 	unsigned long min, max;
183 
184 	min = PFN_UP(memblock_start_of_DRAM());
185 	max = PFN_DOWN(memblock_end_of_DRAM());
186 
187 	/*
188 	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
189 	 * done after the fixed reservations.
190 	 */
191 	arm64_memory_present();
192 
193 	sparse_init();
194 	zone_sizes_init(min, max);
195 
196 	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
197 	max_pfn = max_low_pfn = max;
198 }
199 
200 static inline int free_area(unsigned long pfn, unsigned long end, char *s)
201 {
202 	unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
203 
204 	for (; pfn < end; pfn++) {
205 		struct page *page = pfn_to_page(pfn);
206 		ClearPageReserved(page);
207 		init_page_count(page);
208 		__free_page(page);
209 		pages++;
210 	}
211 
212 	if (size && s)
213 		pr_info("Freeing %s memory: %dK\n", s, size);
214 
215 	return pages;
216 }
217 
218 /*
219  * Poison init memory with an undefined instruction (0x0).
220  */
221 static inline void poison_init_mem(void *s, size_t count)
222 {
223 	memset(s, 0, count);
224 }
225 
226 #ifndef CONFIG_SPARSEMEM_VMEMMAP
227 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
228 {
229 	struct page *start_pg, *end_pg;
230 	unsigned long pg, pgend;
231 
232 	/*
233 	 * Convert start_pfn/end_pfn to a struct page pointer.
234 	 */
235 	start_pg = pfn_to_page(start_pfn - 1) + 1;
236 	end_pg = pfn_to_page(end_pfn - 1) + 1;
237 
238 	/*
239 	 * Convert to physical addresses, and round start upwards and end
240 	 * downwards.
241 	 */
242 	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
243 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
244 
245 	/*
246 	 * If there are free pages between these, free the section of the
247 	 * memmap array.
248 	 */
249 	if (pg < pgend)
250 		free_bootmem(pg, pgend - pg);
251 }
252 
253 /*
254  * The mem_map array can get very big. Free the unused area of the memory map.
255  */
256 static void __init free_unused_memmap(void)
257 {
258 	unsigned long start, prev_end = 0;
259 	struct memblock_region *reg;
260 
261 	for_each_memblock(memory, reg) {
262 		start = __phys_to_pfn(reg->base);
263 
264 #ifdef CONFIG_SPARSEMEM
265 		/*
266 		 * Take care not to free memmap entries that don't exist due
267 		 * to SPARSEMEM sections which aren't present.
268 		 */
269 		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
270 #endif
271 		/*
272 		 * If we had a previous bank, and there is a space between the
273 		 * current bank and the previous, free it.
274 		 */
275 		if (prev_end && prev_end < start)
276 			free_memmap(prev_end, start);
277 
278 		/*
279 		 * Align up here since the VM subsystem insists that the
280 		 * memmap entries are valid from the bank end aligned to
281 		 * MAX_ORDER_NR_PAGES.
282 		 */
283 		prev_end = ALIGN(start + __phys_to_pfn(reg->size),
284 				 MAX_ORDER_NR_PAGES);
285 	}
286 
287 #ifdef CONFIG_SPARSEMEM
288 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
289 		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
290 #endif
291 }
292 #endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
293 
294 /*
295  * mem_init() marks the free areas in the mem_map and tells us how much memory
296  * is free.  This is done after various parts of the system have claimed their
297  * memory after the kernel image.
298  */
299 void __init mem_init(void)
300 {
301 	unsigned long reserved_pages, free_pages;
302 	struct memblock_region *reg;
303 
304 	arm64_swiotlb_init();
305 
306 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
307 
308 #ifndef CONFIG_SPARSEMEM_VMEMMAP
309 	/* this will put all unused low memory onto the freelists */
310 	free_unused_memmap();
311 #endif
312 
313 	totalram_pages += free_all_bootmem();
314 
315 	reserved_pages = free_pages = 0;
316 
317 	for_each_memblock(memory, reg) {
318 		unsigned int pfn1, pfn2;
319 		struct page *page, *end;
320 
321 		pfn1 = __phys_to_pfn(reg->base);
322 		pfn2 = pfn1 + __phys_to_pfn(reg->size);
323 
324 		page = pfn_to_page(pfn1);
325 		end  = pfn_to_page(pfn2 - 1) + 1;
326 
327 		do {
328 			if (PageReserved(page))
329 				reserved_pages++;
330 			else if (!page_count(page))
331 				free_pages++;
332 			page++;
333 		} while (page < end);
334 	}
335 
336 	/*
337 	 * Since our memory may not be contiguous, calculate the real number
338 	 * of pages we have in this system.
339 	 */
340 	pr_info("Memory:");
341 	num_physpages = 0;
342 	for_each_memblock(memory, reg) {
343 		unsigned long pages = memblock_region_memory_end_pfn(reg) -
344 			memblock_region_memory_base_pfn(reg);
345 		num_physpages += pages;
346 		printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
347 	}
348 	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
349 
350 	pr_notice("Memory: %luk/%luk available, %luk reserved\n",
351 		  nr_free_pages() << (PAGE_SHIFT-10),
352 		  free_pages << (PAGE_SHIFT-10),
353 		  reserved_pages << (PAGE_SHIFT-10));
354 
355 #define MLK(b, t) b, t, ((t) - (b)) >> 10
356 #define MLM(b, t) b, t, ((t) - (b)) >> 20
357 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
358 
359 	pr_notice("Virtual kernel memory layout:\n"
360 		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld MB)\n"
361 #ifdef CONFIG_SPARSEMEM_VMEMMAP
362 		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld MB)\n"
363 #endif
364 		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
365 		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
366 		  "      .init : 0x%p" " - 0x%p" "   (%6ld kB)\n"
367 		  "      .text : 0x%p" " - 0x%p" "   (%6ld kB)\n"
368 		  "      .data : 0x%p" " - 0x%p" "   (%6ld kB)\n",
369 		  MLM(VMALLOC_START, VMALLOC_END),
370 #ifdef CONFIG_SPARSEMEM_VMEMMAP
371 		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
372 		      (unsigned long)virt_to_page(high_memory)),
373 #endif
374 		  MLM(MODULES_VADDR, MODULES_END),
375 		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
376 
377 		  MLK_ROUNDUP(__init_begin, __init_end),
378 		  MLK_ROUNDUP(_text, _etext),
379 		  MLK_ROUNDUP(_sdata, _edata));
380 
381 #undef MLK
382 #undef MLM
383 #undef MLK_ROUNDUP
384 
385 	/*
386 	 * Check boundaries twice: Some fundamental inconsistencies can be
387 	 * detected at build time already.
388 	 */
389 #ifdef CONFIG_COMPAT
390 	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
391 #endif
392 	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
393 	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
394 
395 	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
396 		extern int sysctl_overcommit_memory;
397 		/*
398 		 * On a machine this small we won't get anywhere without
399 		 * overcommit, so turn it on by default.
400 		 */
401 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
402 	}
403 }
404 
405 void free_initmem(void)
406 {
407 	poison_init_mem(__init_begin, __init_end - __init_begin);
408 	totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
409 				    __phys_to_pfn(__pa(__init_end)),
410 				    "init");
411 }
412 
413 #ifdef CONFIG_BLK_DEV_INITRD
414 
415 static int keep_initrd;
416 
417 void free_initrd_mem(unsigned long start, unsigned long end)
418 {
419 	if (!keep_initrd) {
420 		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
421 		totalram_pages += free_area(__phys_to_pfn(__pa(start)),
422 					    __phys_to_pfn(__pa(end)),
423 					    "initrd");
424 	}
425 }
426 
427 static int __init keepinitrd_setup(char *__unused)
428 {
429 	keep_initrd = 1;
430 	return 1;
431 }
432 
433 __setup("keepinitrd", keepinitrd_setup);
434 #endif
435