xref: /openbmc/linux/arch/arm64/mm/init.c (revision d2999e1b)
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-mapping.h>
34 #include <linux/dma-contiguous.h>
35 
36 #include <asm/sections.h>
37 #include <asm/setup.h>
38 #include <asm/sizes.h>
39 #include <asm/tlb.h>
40 
41 #include "mm.h"
42 
43 phys_addr_t memstart_addr __read_mostly = 0;
44 
45 #ifdef CONFIG_BLK_DEV_INITRD
46 static int __init early_initrd(char *p)
47 {
48 	unsigned long start, size;
49 	char *endp;
50 
51 	start = memparse(p, &endp);
52 	if (*endp == ',') {
53 		size = memparse(endp + 1, NULL);
54 
55 		initrd_start = (unsigned long)__va(start);
56 		initrd_end = (unsigned long)__va(start + size);
57 	}
58 	return 0;
59 }
60 early_param("initrd", early_initrd);
61 #endif
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_dma = min;
68 
69 	memset(zone_size, 0, sizeof(zone_size));
70 
71 	/* 4GB maximum for 32-bit only capable devices */
72 	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
73 		unsigned long max_dma_phys =
74 			(unsigned long)(dma_to_phys(NULL, DMA_BIT_MASK(32)) + 1);
75 		max_dma = max(min, min(max, max_dma_phys >> PAGE_SHIFT));
76 		zone_size[ZONE_DMA] = max_dma - min;
77 	}
78 	zone_size[ZONE_NORMAL] = max - max_dma;
79 
80 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
81 
82 	for_each_memblock(memory, reg) {
83 		unsigned long start = memblock_region_memory_base_pfn(reg);
84 		unsigned long end = memblock_region_memory_end_pfn(reg);
85 
86 		if (start >= max)
87 			continue;
88 
89 		if (IS_ENABLED(CONFIG_ZONE_DMA) && start < max_dma) {
90 			unsigned long dma_end = min(end, max_dma);
91 			zhole_size[ZONE_DMA] -= dma_end - start;
92 		}
93 
94 		if (end > max_dma) {
95 			unsigned long normal_end = min(end, max);
96 			unsigned long normal_start = max(start, max_dma);
97 			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
98 		}
99 	}
100 
101 	free_area_init_node(0, zone_size, min, zhole_size);
102 }
103 
104 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
105 int pfn_valid(unsigned long pfn)
106 {
107 	return memblock_is_memory(pfn << PAGE_SHIFT);
108 }
109 EXPORT_SYMBOL(pfn_valid);
110 #endif
111 
112 #ifndef CONFIG_SPARSEMEM
113 static void arm64_memory_present(void)
114 {
115 }
116 #else
117 static void arm64_memory_present(void)
118 {
119 	struct memblock_region *reg;
120 
121 	for_each_memblock(memory, reg)
122 		memory_present(0, memblock_region_memory_base_pfn(reg),
123 			       memblock_region_memory_end_pfn(reg));
124 }
125 #endif
126 
127 void __init arm64_memblock_init(void)
128 {
129 	phys_addr_t dma_phys_limit = 0;
130 
131 	/* Register the kernel text, kernel data and initrd with memblock */
132 	memblock_reserve(__pa(_text), _end - _text);
133 #ifdef CONFIG_BLK_DEV_INITRD
134 	if (initrd_start)
135 		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
136 #endif
137 
138 	/*
139 	 * Reserve the page tables.  These are already in use,
140 	 * and can only be in node 0.
141 	 */
142 	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
143 	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
144 
145 	early_init_fdt_scan_reserved_mem();
146 
147 	/* 4GB maximum for 32-bit only capable devices */
148 	if (IS_ENABLED(CONFIG_ZONE_DMA))
149 		dma_phys_limit = dma_to_phys(NULL, DMA_BIT_MASK(32)) + 1;
150 	dma_contiguous_reserve(dma_phys_limit);
151 
152 	memblock_allow_resize();
153 	memblock_dump_all();
154 }
155 
156 void __init bootmem_init(void)
157 {
158 	unsigned long min, max;
159 
160 	min = PFN_UP(memblock_start_of_DRAM());
161 	max = PFN_DOWN(memblock_end_of_DRAM());
162 
163 	/*
164 	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
165 	 * done after the fixed reservations.
166 	 */
167 	arm64_memory_present();
168 
169 	sparse_init();
170 	zone_sizes_init(min, max);
171 
172 	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
173 	max_pfn = max_low_pfn = max;
174 }
175 
176 #ifndef CONFIG_SPARSEMEM_VMEMMAP
177 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
178 {
179 	struct page *start_pg, *end_pg;
180 	unsigned long pg, pgend;
181 
182 	/*
183 	 * Convert start_pfn/end_pfn to a struct page pointer.
184 	 */
185 	start_pg = pfn_to_page(start_pfn - 1) + 1;
186 	end_pg = pfn_to_page(end_pfn - 1) + 1;
187 
188 	/*
189 	 * Convert to physical addresses, and round start upwards and end
190 	 * downwards.
191 	 */
192 	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
193 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
194 
195 	/*
196 	 * If there are free pages between these, free the section of the
197 	 * memmap array.
198 	 */
199 	if (pg < pgend)
200 		free_bootmem(pg, pgend - pg);
201 }
202 
203 /*
204  * The mem_map array can get very big. Free the unused area of the memory map.
205  */
206 static void __init free_unused_memmap(void)
207 {
208 	unsigned long start, prev_end = 0;
209 	struct memblock_region *reg;
210 
211 	for_each_memblock(memory, reg) {
212 		start = __phys_to_pfn(reg->base);
213 
214 #ifdef CONFIG_SPARSEMEM
215 		/*
216 		 * Take care not to free memmap entries that don't exist due
217 		 * to SPARSEMEM sections which aren't present.
218 		 */
219 		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
220 #endif
221 		/*
222 		 * If we had a previous bank, and there is a space between the
223 		 * current bank and the previous, free it.
224 		 */
225 		if (prev_end && prev_end < start)
226 			free_memmap(prev_end, start);
227 
228 		/*
229 		 * Align up here since the VM subsystem insists that the
230 		 * memmap entries are valid from the bank end aligned to
231 		 * MAX_ORDER_NR_PAGES.
232 		 */
233 		prev_end = ALIGN(start + __phys_to_pfn(reg->size),
234 				 MAX_ORDER_NR_PAGES);
235 	}
236 
237 #ifdef CONFIG_SPARSEMEM
238 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
239 		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
240 #endif
241 }
242 #endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
243 
244 /*
245  * mem_init() marks the free areas in the mem_map and tells us how much memory
246  * is free.  This is done after various parts of the system have claimed their
247  * memory after the kernel image.
248  */
249 void __init mem_init(void)
250 {
251 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
252 
253 #ifndef CONFIG_SPARSEMEM_VMEMMAP
254 	free_unused_memmap();
255 #endif
256 	/* this will put all unused low memory onto the freelists */
257 	free_all_bootmem();
258 
259 	mem_init_print_info(NULL);
260 
261 #define MLK(b, t) b, t, ((t) - (b)) >> 10
262 #define MLM(b, t) b, t, ((t) - (b)) >> 20
263 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
264 
265 	pr_notice("Virtual kernel memory layout:\n"
266 		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld MB)\n"
267 #ifdef CONFIG_SPARSEMEM_VMEMMAP
268 		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld MB)\n"
269 #endif
270 		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
271 		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
272 		  "      .init : 0x%p" " - 0x%p" "   (%6ld kB)\n"
273 		  "      .text : 0x%p" " - 0x%p" "   (%6ld kB)\n"
274 		  "      .data : 0x%p" " - 0x%p" "   (%6ld kB)\n",
275 		  MLM(VMALLOC_START, VMALLOC_END),
276 #ifdef CONFIG_SPARSEMEM_VMEMMAP
277 		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
278 		      (unsigned long)virt_to_page(high_memory)),
279 #endif
280 		  MLM(MODULES_VADDR, MODULES_END),
281 		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
282 
283 		  MLK_ROUNDUP(__init_begin, __init_end),
284 		  MLK_ROUNDUP(_text, _etext),
285 		  MLK_ROUNDUP(_sdata, _edata));
286 
287 #undef MLK
288 #undef MLM
289 #undef MLK_ROUNDUP
290 
291 	/*
292 	 * Check boundaries twice: Some fundamental inconsistencies can be
293 	 * detected at build time already.
294 	 */
295 #ifdef CONFIG_COMPAT
296 	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
297 #endif
298 	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
299 	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
300 
301 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
302 		extern int sysctl_overcommit_memory;
303 		/*
304 		 * On a machine this small we won't get anywhere without
305 		 * overcommit, so turn it on by default.
306 		 */
307 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
308 	}
309 }
310 
311 void free_initmem(void)
312 {
313 	free_initmem_default(0);
314 }
315 
316 #ifdef CONFIG_BLK_DEV_INITRD
317 
318 static int keep_initrd;
319 
320 void free_initrd_mem(unsigned long start, unsigned long end)
321 {
322 	if (!keep_initrd)
323 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
324 }
325 
326 static int __init keepinitrd_setup(char *__unused)
327 {
328 	keep_initrd = 1;
329 	return 1;
330 }
331 
332 __setup("keepinitrd", keepinitrd_setup);
333 #endif
334