xref: /openbmc/linux/arch/arm64/mm/init.c (revision c4ee0af3)
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/sections.h>
35 #include <asm/setup.h>
36 #include <asm/sizes.h>
37 #include <asm/tlb.h>
38 
39 #include "mm.h"
40 
41 phys_addr_t memstart_addr __read_mostly = 0;
42 
43 #ifdef CONFIG_BLK_DEV_INITRD
44 static int __init early_initrd(char *p)
45 {
46 	unsigned long start, size;
47 	char *endp;
48 
49 	start = memparse(p, &endp);
50 	if (*endp == ',') {
51 		size = memparse(endp + 1, NULL);
52 
53 		initrd_start = (unsigned long)__va(start);
54 		initrd_end = (unsigned long)__va(start + size);
55 	}
56 	return 0;
57 }
58 early_param("initrd", early_initrd);
59 #endif
60 
61 #define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)
62 
63 static void __init zone_sizes_init(unsigned long min, unsigned long max)
64 {
65 	struct memblock_region *reg;
66 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
67 	unsigned long max_dma32 = min;
68 
69 	memset(zone_size, 0, sizeof(zone_size));
70 
71 #ifdef CONFIG_ZONE_DMA32
72 	/* 4GB maximum for 32-bit only capable devices */
73 	max_dma32 = max(min, min(max, MAX_DMA32_PFN));
74 	zone_size[ZONE_DMA32] = max_dma32 - min;
75 #endif
76 	zone_size[ZONE_NORMAL] = max - max_dma32;
77 
78 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
79 
80 	for_each_memblock(memory, reg) {
81 		unsigned long start = memblock_region_memory_base_pfn(reg);
82 		unsigned long end = memblock_region_memory_end_pfn(reg);
83 
84 		if (start >= max)
85 			continue;
86 #ifdef CONFIG_ZONE_DMA32
87 		if (start < max_dma32) {
88 			unsigned long dma_end = min(end, max_dma32);
89 			zhole_size[ZONE_DMA32] -= dma_end - start;
90 		}
91 #endif
92 		if (end > max_dma32) {
93 			unsigned long normal_end = min(end, max);
94 			unsigned long normal_start = max(start, max_dma32);
95 			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
96 		}
97 	}
98 
99 	free_area_init_node(0, zone_size, min, zhole_size);
100 }
101 
102 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
103 int pfn_valid(unsigned long pfn)
104 {
105 	return memblock_is_memory(pfn << PAGE_SHIFT);
106 }
107 EXPORT_SYMBOL(pfn_valid);
108 #endif
109 
110 #ifndef CONFIG_SPARSEMEM
111 static void arm64_memory_present(void)
112 {
113 }
114 #else
115 static void arm64_memory_present(void)
116 {
117 	struct memblock_region *reg;
118 
119 	for_each_memblock(memory, reg)
120 		memory_present(0, memblock_region_memory_base_pfn(reg),
121 			       memblock_region_memory_end_pfn(reg));
122 }
123 #endif
124 
125 void __init arm64_memblock_init(void)
126 {
127 	u64 *reserve_map, base, size;
128 
129 	/* Register the kernel text, kernel data and initrd with memblock */
130 	memblock_reserve(__pa(_text), _end - _text);
131 #ifdef CONFIG_BLK_DEV_INITRD
132 	if (initrd_start)
133 		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
134 #endif
135 
136 	/*
137 	 * Reserve the page tables.  These are already in use,
138 	 * and can only be in node 0.
139 	 */
140 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
141 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
142 
143 	/* Reserve the dtb region */
144 	memblock_reserve(virt_to_phys(initial_boot_params),
145 			 be32_to_cpu(initial_boot_params->totalsize));
146 
147 	/*
148 	 * Process the reserve map.  This will probably overlap the initrd
149 	 * and dtb locations which are already reserved, but overlapping
150 	 * doesn't hurt anything
151 	 */
152 	reserve_map = ((void*)initial_boot_params) +
153 			be32_to_cpu(initial_boot_params->off_mem_rsvmap);
154 	while (1) {
155 		base = be64_to_cpup(reserve_map++);
156 		size = be64_to_cpup(reserve_map++);
157 		if (!size)
158 			break;
159 		memblock_reserve(base, size);
160 	}
161 
162 	memblock_allow_resize();
163 	memblock_dump_all();
164 }
165 
166 void __init bootmem_init(void)
167 {
168 	unsigned long min, max;
169 
170 	min = PFN_UP(memblock_start_of_DRAM());
171 	max = PFN_DOWN(memblock_end_of_DRAM());
172 
173 	/*
174 	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
175 	 * done after the fixed reservations.
176 	 */
177 	arm64_memory_present();
178 
179 	sparse_init();
180 	zone_sizes_init(min, max);
181 
182 	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
183 	max_pfn = max_low_pfn = max;
184 }
185 
186 #ifndef CONFIG_SPARSEMEM_VMEMMAP
187 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
188 {
189 	struct page *start_pg, *end_pg;
190 	unsigned long pg, pgend;
191 
192 	/*
193 	 * Convert start_pfn/end_pfn to a struct page pointer.
194 	 */
195 	start_pg = pfn_to_page(start_pfn - 1) + 1;
196 	end_pg = pfn_to_page(end_pfn - 1) + 1;
197 
198 	/*
199 	 * Convert to physical addresses, and round start upwards and end
200 	 * downwards.
201 	 */
202 	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
203 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
204 
205 	/*
206 	 * If there are free pages between these, free the section of the
207 	 * memmap array.
208 	 */
209 	if (pg < pgend)
210 		free_bootmem(pg, pgend - pg);
211 }
212 
213 /*
214  * The mem_map array can get very big. Free the unused area of the memory map.
215  */
216 static void __init free_unused_memmap(void)
217 {
218 	unsigned long start, prev_end = 0;
219 	struct memblock_region *reg;
220 
221 	for_each_memblock(memory, reg) {
222 		start = __phys_to_pfn(reg->base);
223 
224 #ifdef CONFIG_SPARSEMEM
225 		/*
226 		 * Take care not to free memmap entries that don't exist due
227 		 * to SPARSEMEM sections which aren't present.
228 		 */
229 		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
230 #endif
231 		/*
232 		 * If we had a previous bank, and there is a space between the
233 		 * current bank and the previous, free it.
234 		 */
235 		if (prev_end && prev_end < start)
236 			free_memmap(prev_end, start);
237 
238 		/*
239 		 * Align up here since the VM subsystem insists that the
240 		 * memmap entries are valid from the bank end aligned to
241 		 * MAX_ORDER_NR_PAGES.
242 		 */
243 		prev_end = ALIGN(start + __phys_to_pfn(reg->size),
244 				 MAX_ORDER_NR_PAGES);
245 	}
246 
247 #ifdef CONFIG_SPARSEMEM
248 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
249 		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
250 #endif
251 }
252 #endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
253 
254 /*
255  * mem_init() marks the free areas in the mem_map and tells us how much memory
256  * is free.  This is done after various parts of the system have claimed their
257  * memory after the kernel image.
258  */
259 void __init mem_init(void)
260 {
261 	arm64_swiotlb_init();
262 
263 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
264 
265 #ifndef CONFIG_SPARSEMEM_VMEMMAP
266 	free_unused_memmap();
267 #endif
268 	/* this will put all unused low memory onto the freelists */
269 	free_all_bootmem();
270 
271 	mem_init_print_info(NULL);
272 
273 #define MLK(b, t) b, t, ((t) - (b)) >> 10
274 #define MLM(b, t) b, t, ((t) - (b)) >> 20
275 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
276 
277 	pr_notice("Virtual kernel memory layout:\n"
278 		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld MB)\n"
279 #ifdef CONFIG_SPARSEMEM_VMEMMAP
280 		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld MB)\n"
281 #endif
282 		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
283 		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
284 		  "      .init : 0x%p" " - 0x%p" "   (%6ld kB)\n"
285 		  "      .text : 0x%p" " - 0x%p" "   (%6ld kB)\n"
286 		  "      .data : 0x%p" " - 0x%p" "   (%6ld kB)\n",
287 		  MLM(VMALLOC_START, VMALLOC_END),
288 #ifdef CONFIG_SPARSEMEM_VMEMMAP
289 		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
290 		      (unsigned long)virt_to_page(high_memory)),
291 #endif
292 		  MLM(MODULES_VADDR, MODULES_END),
293 		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
294 
295 		  MLK_ROUNDUP(__init_begin, __init_end),
296 		  MLK_ROUNDUP(_text, _etext),
297 		  MLK_ROUNDUP(_sdata, _edata));
298 
299 #undef MLK
300 #undef MLM
301 #undef MLK_ROUNDUP
302 
303 	/*
304 	 * Check boundaries twice: Some fundamental inconsistencies can be
305 	 * detected at build time already.
306 	 */
307 #ifdef CONFIG_COMPAT
308 	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
309 #endif
310 	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
311 	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
312 
313 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
314 		extern int sysctl_overcommit_memory;
315 		/*
316 		 * On a machine this small we won't get anywhere without
317 		 * overcommit, so turn it on by default.
318 		 */
319 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
320 	}
321 }
322 
323 void free_initmem(void)
324 {
325 	free_initmem_default(0);
326 }
327 
328 #ifdef CONFIG_BLK_DEV_INITRD
329 
330 static int keep_initrd;
331 
332 void free_initrd_mem(unsigned long start, unsigned long end)
333 {
334 	if (!keep_initrd)
335 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
336 }
337 
338 static int __init keepinitrd_setup(char *__unused)
339 {
340 	keep_initrd = 1;
341 	return 1;
342 }
343 
344 __setup("keepinitrd", keepinitrd_setup);
345 #endif
346