xref: /openbmc/linux/arch/arm64/mm/init.c (revision 483eb062)
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 #include <linux/dma-contiguous.h>
34 
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 phys_addr_t memstart_addr __read_mostly = 0;
43 
44 #ifdef CONFIG_BLK_DEV_INITRD
45 static int __init early_initrd(char *p)
46 {
47 	unsigned long start, size;
48 	char *endp;
49 
50 	start = memparse(p, &endp);
51 	if (*endp == ',') {
52 		size = memparse(endp + 1, NULL);
53 
54 		initrd_start = (unsigned long)__va(start);
55 		initrd_end = (unsigned long)__va(start + size);
56 	}
57 	return 0;
58 }
59 early_param("initrd", early_initrd);
60 #endif
61 
62 #define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)
63 
64 static void __init zone_sizes_init(unsigned long min, unsigned long max)
65 {
66 	struct memblock_region *reg;
67 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
68 	unsigned long max_dma32 = min;
69 
70 	memset(zone_size, 0, sizeof(zone_size));
71 
72 #ifdef CONFIG_ZONE_DMA32
73 	/* 4GB maximum for 32-bit only capable devices */
74 	max_dma32 = max(min, min(max, MAX_DMA32_PFN));
75 	zone_size[ZONE_DMA32] = max_dma32 - min;
76 #endif
77 	zone_size[ZONE_NORMAL] = max - max_dma32;
78 
79 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
80 
81 	for_each_memblock(memory, reg) {
82 		unsigned long start = memblock_region_memory_base_pfn(reg);
83 		unsigned long end = memblock_region_memory_end_pfn(reg);
84 
85 		if (start >= max)
86 			continue;
87 #ifdef CONFIG_ZONE_DMA32
88 		if (start < max_dma32) {
89 			unsigned long dma_end = min(end, max_dma32);
90 			zhole_size[ZONE_DMA32] -= dma_end - start;
91 		}
92 #endif
93 		if (end > max_dma32) {
94 			unsigned long normal_end = min(end, max);
95 			unsigned long normal_start = max(start, max_dma32);
96 			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
97 		}
98 	}
99 
100 	free_area_init_node(0, zone_size, min, zhole_size);
101 }
102 
103 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
104 int pfn_valid(unsigned long pfn)
105 {
106 	return memblock_is_memory(pfn << PAGE_SHIFT);
107 }
108 EXPORT_SYMBOL(pfn_valid);
109 #endif
110 
111 #ifndef CONFIG_SPARSEMEM
112 static void arm64_memory_present(void)
113 {
114 }
115 #else
116 static void arm64_memory_present(void)
117 {
118 	struct memblock_region *reg;
119 
120 	for_each_memblock(memory, reg)
121 		memory_present(0, memblock_region_memory_base_pfn(reg),
122 			       memblock_region_memory_end_pfn(reg));
123 }
124 #endif
125 
126 void __init arm64_memblock_init(void)
127 {
128 	u64 *reserve_map, base, size;
129 
130 	/* Register the kernel text, kernel data and initrd with memblock */
131 	memblock_reserve(__pa(_text), _end - _text);
132 #ifdef CONFIG_BLK_DEV_INITRD
133 	if (initrd_start)
134 		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
135 #endif
136 
137 	/*
138 	 * Reserve the page tables.  These are already in use,
139 	 * and can only be in node 0.
140 	 */
141 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
142 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
143 
144 	/* Reserve the dtb region */
145 	memblock_reserve(virt_to_phys(initial_boot_params),
146 			 be32_to_cpu(initial_boot_params->totalsize));
147 
148 	/*
149 	 * Process the reserve map.  This will probably overlap the initrd
150 	 * and dtb locations which are already reserved, but overlapping
151 	 * doesn't hurt anything
152 	 */
153 	reserve_map = ((void*)initial_boot_params) +
154 			be32_to_cpu(initial_boot_params->off_mem_rsvmap);
155 	while (1) {
156 		base = be64_to_cpup(reserve_map++);
157 		size = be64_to_cpup(reserve_map++);
158 		if (!size)
159 			break;
160 		memblock_reserve(base, size);
161 	}
162 
163 	dma_contiguous_reserve(0);
164 
165 	memblock_allow_resize();
166 	memblock_dump_all();
167 }
168 
169 void __init bootmem_init(void)
170 {
171 	unsigned long min, max;
172 
173 	min = PFN_UP(memblock_start_of_DRAM());
174 	max = PFN_DOWN(memblock_end_of_DRAM());
175 
176 	/*
177 	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
178 	 * done after the fixed reservations.
179 	 */
180 	arm64_memory_present();
181 
182 	sparse_init();
183 	zone_sizes_init(min, max);
184 
185 	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
186 	max_pfn = max_low_pfn = max;
187 }
188 
189 #ifndef CONFIG_SPARSEMEM_VMEMMAP
190 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
191 {
192 	struct page *start_pg, *end_pg;
193 	unsigned long pg, pgend;
194 
195 	/*
196 	 * Convert start_pfn/end_pfn to a struct page pointer.
197 	 */
198 	start_pg = pfn_to_page(start_pfn - 1) + 1;
199 	end_pg = pfn_to_page(end_pfn - 1) + 1;
200 
201 	/*
202 	 * Convert to physical addresses, and round start upwards and end
203 	 * downwards.
204 	 */
205 	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
206 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
207 
208 	/*
209 	 * If there are free pages between these, free the section of the
210 	 * memmap array.
211 	 */
212 	if (pg < pgend)
213 		free_bootmem(pg, pgend - pg);
214 }
215 
216 /*
217  * The mem_map array can get very big. Free the unused area of the memory map.
218  */
219 static void __init free_unused_memmap(void)
220 {
221 	unsigned long start, prev_end = 0;
222 	struct memblock_region *reg;
223 
224 	for_each_memblock(memory, reg) {
225 		start = __phys_to_pfn(reg->base);
226 
227 #ifdef CONFIG_SPARSEMEM
228 		/*
229 		 * Take care not to free memmap entries that don't exist due
230 		 * to SPARSEMEM sections which aren't present.
231 		 */
232 		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
233 #endif
234 		/*
235 		 * If we had a previous bank, and there is a space between the
236 		 * current bank and the previous, free it.
237 		 */
238 		if (prev_end && prev_end < start)
239 			free_memmap(prev_end, start);
240 
241 		/*
242 		 * Align up here since the VM subsystem insists that the
243 		 * memmap entries are valid from the bank end aligned to
244 		 * MAX_ORDER_NR_PAGES.
245 		 */
246 		prev_end = ALIGN(start + __phys_to_pfn(reg->size),
247 				 MAX_ORDER_NR_PAGES);
248 	}
249 
250 #ifdef CONFIG_SPARSEMEM
251 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
252 		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
253 #endif
254 }
255 #endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
256 
257 /*
258  * mem_init() marks the free areas in the mem_map and tells us how much memory
259  * is free.  This is done after various parts of the system have claimed their
260  * memory after the kernel image.
261  */
262 void __init mem_init(void)
263 {
264 	arm64_swiotlb_init();
265 
266 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
267 
268 #ifndef CONFIG_SPARSEMEM_VMEMMAP
269 	free_unused_memmap();
270 #endif
271 	/* this will put all unused low memory onto the freelists */
272 	free_all_bootmem();
273 
274 	mem_init_print_info(NULL);
275 
276 #define MLK(b, t) b, t, ((t) - (b)) >> 10
277 #define MLM(b, t) b, t, ((t) - (b)) >> 20
278 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
279 
280 	pr_notice("Virtual kernel memory layout:\n"
281 		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld MB)\n"
282 #ifdef CONFIG_SPARSEMEM_VMEMMAP
283 		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld MB)\n"
284 #endif
285 		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
286 		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
287 		  "      .init : 0x%p" " - 0x%p" "   (%6ld kB)\n"
288 		  "      .text : 0x%p" " - 0x%p" "   (%6ld kB)\n"
289 		  "      .data : 0x%p" " - 0x%p" "   (%6ld kB)\n",
290 		  MLM(VMALLOC_START, VMALLOC_END),
291 #ifdef CONFIG_SPARSEMEM_VMEMMAP
292 		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
293 		      (unsigned long)virt_to_page(high_memory)),
294 #endif
295 		  MLM(MODULES_VADDR, MODULES_END),
296 		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
297 
298 		  MLK_ROUNDUP(__init_begin, __init_end),
299 		  MLK_ROUNDUP(_text, _etext),
300 		  MLK_ROUNDUP(_sdata, _edata));
301 
302 #undef MLK
303 #undef MLM
304 #undef MLK_ROUNDUP
305 
306 	/*
307 	 * Check boundaries twice: Some fundamental inconsistencies can be
308 	 * detected at build time already.
309 	 */
310 #ifdef CONFIG_COMPAT
311 	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
312 #endif
313 	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
314 	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
315 
316 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
317 		extern int sysctl_overcommit_memory;
318 		/*
319 		 * On a machine this small we won't get anywhere without
320 		 * overcommit, so turn it on by default.
321 		 */
322 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
323 	}
324 }
325 
326 void free_initmem(void)
327 {
328 	free_initmem_default(0);
329 }
330 
331 #ifdef CONFIG_BLK_DEV_INITRD
332 
333 static int keep_initrd;
334 
335 void free_initrd_mem(unsigned long start, unsigned long end)
336 {
337 	if (!keep_initrd)
338 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
339 }
340 
341 static int __init keepinitrd_setup(char *__unused)
342 {
343 	keep_initrd = 1;
344 	return 1;
345 }
346 
347 __setup("keepinitrd", keepinitrd_setup);
348 #endif
349