xref: /openbmc/linux/arch/arm64/mm/init.c (revision c819e2cf)
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 #include <linux/efi.h>
36 
37 #include <asm/fixmap.h>
38 #include <asm/sections.h>
39 #include <asm/setup.h>
40 #include <asm/sizes.h>
41 #include <asm/tlb.h>
42 #include <asm/alternative.h>
43 
44 #include "mm.h"
45 
46 phys_addr_t memstart_addr __read_mostly = 0;
47 
48 #ifdef CONFIG_BLK_DEV_INITRD
49 static int __init early_initrd(char *p)
50 {
51 	unsigned long start, size;
52 	char *endp;
53 
54 	start = memparse(p, &endp);
55 	if (*endp == ',') {
56 		size = memparse(endp + 1, NULL);
57 
58 		initrd_start = (unsigned long)__va(start);
59 		initrd_end = (unsigned long)__va(start + size);
60 	}
61 	return 0;
62 }
63 early_param("initrd", early_initrd);
64 #endif
65 
66 /*
67  * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
68  * currently assumes that for memory starting above 4G, 32-bit devices will
69  * use a DMA offset.
70  */
71 static phys_addr_t max_zone_dma_phys(void)
72 {
73 	phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
74 	return min(offset + (1ULL << 32), memblock_end_of_DRAM());
75 }
76 
77 static void __init zone_sizes_init(unsigned long min, unsigned long max)
78 {
79 	struct memblock_region *reg;
80 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
81 	unsigned long max_dma = min;
82 
83 	memset(zone_size, 0, sizeof(zone_size));
84 
85 	/* 4GB maximum for 32-bit only capable devices */
86 	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
87 		max_dma = PFN_DOWN(max_zone_dma_phys());
88 		zone_size[ZONE_DMA] = max_dma - min;
89 	}
90 	zone_size[ZONE_NORMAL] = max - max_dma;
91 
92 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
93 
94 	for_each_memblock(memory, reg) {
95 		unsigned long start = memblock_region_memory_base_pfn(reg);
96 		unsigned long end = memblock_region_memory_end_pfn(reg);
97 
98 		if (start >= max)
99 			continue;
100 
101 		if (IS_ENABLED(CONFIG_ZONE_DMA) && start < max_dma) {
102 			unsigned long dma_end = min(end, max_dma);
103 			zhole_size[ZONE_DMA] -= dma_end - start;
104 		}
105 
106 		if (end > max_dma) {
107 			unsigned long normal_end = min(end, max);
108 			unsigned long normal_start = max(start, max_dma);
109 			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
110 		}
111 	}
112 
113 	free_area_init_node(0, zone_size, min, zhole_size);
114 }
115 
116 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
117 int pfn_valid(unsigned long pfn)
118 {
119 	return memblock_is_memory(pfn << PAGE_SHIFT);
120 }
121 EXPORT_SYMBOL(pfn_valid);
122 #endif
123 
124 #ifndef CONFIG_SPARSEMEM
125 static void arm64_memory_present(void)
126 {
127 }
128 #else
129 static void arm64_memory_present(void)
130 {
131 	struct memblock_region *reg;
132 
133 	for_each_memblock(memory, reg)
134 		memory_present(0, memblock_region_memory_base_pfn(reg),
135 			       memblock_region_memory_end_pfn(reg));
136 }
137 #endif
138 
139 void __init arm64_memblock_init(void)
140 {
141 	phys_addr_t dma_phys_limit = 0;
142 
143 	/*
144 	 * Register the kernel text, kernel data, initrd, and initial
145 	 * pagetables with memblock.
146 	 */
147 	memblock_reserve(__pa(_text), _end - _text);
148 #ifdef CONFIG_BLK_DEV_INITRD
149 	if (initrd_start)
150 		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
151 #endif
152 
153 	early_init_fdt_scan_reserved_mem();
154 
155 	/* 4GB maximum for 32-bit only capable devices */
156 	if (IS_ENABLED(CONFIG_ZONE_DMA))
157 		dma_phys_limit = max_zone_dma_phys();
158 	dma_contiguous_reserve(dma_phys_limit);
159 
160 	memblock_allow_resize();
161 	memblock_dump_all();
162 }
163 
164 void __init bootmem_init(void)
165 {
166 	unsigned long min, max;
167 
168 	min = PFN_UP(memblock_start_of_DRAM());
169 	max = PFN_DOWN(memblock_end_of_DRAM());
170 
171 	/*
172 	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
173 	 * done after the fixed reservations.
174 	 */
175 	arm64_memory_present();
176 
177 	sparse_init();
178 	zone_sizes_init(min, max);
179 
180 	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
181 	max_pfn = max_low_pfn = max;
182 }
183 
184 #ifndef CONFIG_SPARSEMEM_VMEMMAP
185 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
186 {
187 	struct page *start_pg, *end_pg;
188 	unsigned long pg, pgend;
189 
190 	/*
191 	 * Convert start_pfn/end_pfn to a struct page pointer.
192 	 */
193 	start_pg = pfn_to_page(start_pfn - 1) + 1;
194 	end_pg = pfn_to_page(end_pfn - 1) + 1;
195 
196 	/*
197 	 * Convert to physical addresses, and round start upwards and end
198 	 * downwards.
199 	 */
200 	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
201 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
202 
203 	/*
204 	 * If there are free pages between these, free the section of the
205 	 * memmap array.
206 	 */
207 	if (pg < pgend)
208 		free_bootmem(pg, pgend - pg);
209 }
210 
211 /*
212  * The mem_map array can get very big. Free the unused area of the memory map.
213  */
214 static void __init free_unused_memmap(void)
215 {
216 	unsigned long start, prev_end = 0;
217 	struct memblock_region *reg;
218 
219 	for_each_memblock(memory, reg) {
220 		start = __phys_to_pfn(reg->base);
221 
222 #ifdef CONFIG_SPARSEMEM
223 		/*
224 		 * Take care not to free memmap entries that don't exist due
225 		 * to SPARSEMEM sections which aren't present.
226 		 */
227 		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
228 #endif
229 		/*
230 		 * If we had a previous bank, and there is a space between the
231 		 * current bank and the previous, free it.
232 		 */
233 		if (prev_end && prev_end < start)
234 			free_memmap(prev_end, start);
235 
236 		/*
237 		 * Align up here since the VM subsystem insists that the
238 		 * memmap entries are valid from the bank end aligned to
239 		 * MAX_ORDER_NR_PAGES.
240 		 */
241 		prev_end = ALIGN(start + __phys_to_pfn(reg->size),
242 				 MAX_ORDER_NR_PAGES);
243 	}
244 
245 #ifdef CONFIG_SPARSEMEM
246 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
247 		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
248 #endif
249 }
250 #endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
251 
252 /*
253  * mem_init() marks the free areas in the mem_map and tells us how much memory
254  * is free.  This is done after various parts of the system have claimed their
255  * memory after the kernel image.
256  */
257 void __init mem_init(void)
258 {
259 	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
260 
261 #ifndef CONFIG_SPARSEMEM_VMEMMAP
262 	free_unused_memmap();
263 #endif
264 	/* this will put all unused low memory onto the freelists */
265 	free_all_bootmem();
266 
267 	mem_init_print_info(NULL);
268 
269 #define MLK(b, t) b, t, ((t) - (b)) >> 10
270 #define MLM(b, t) b, t, ((t) - (b)) >> 20
271 #define MLG(b, t) b, t, ((t) - (b)) >> 30
272 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
273 
274 	pr_notice("Virtual kernel memory layout:\n"
275 		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld GB)\n"
276 #ifdef CONFIG_SPARSEMEM_VMEMMAP
277 		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld GB maximum)\n"
278 		  "              0x%16lx - 0x%16lx   (%6ld MB actual)\n"
279 #endif
280 		  "    PCI I/O : 0x%16lx - 0x%16lx   (%6ld MB)\n"
281 		  "    fixed   : 0x%16lx - 0x%16lx   (%6ld KB)\n"
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 		  MLG(VMALLOC_START, VMALLOC_END),
288 #ifdef CONFIG_SPARSEMEM_VMEMMAP
289 		  MLG((unsigned long)vmemmap,
290 		      (unsigned long)vmemmap + VMEMMAP_SIZE),
291 		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
292 		      (unsigned long)virt_to_page(high_memory)),
293 #endif
294 		  MLM((unsigned long)PCI_IOBASE, (unsigned long)PCI_IOBASE + SZ_16M),
295 		  MLK(FIXADDR_START, FIXADDR_TOP),
296 		  MLM(MODULES_VADDR, MODULES_END),
297 		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
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 	free_alternatives_memory();
330 }
331 
332 #ifdef CONFIG_BLK_DEV_INITRD
333 
334 static int keep_initrd;
335 
336 void free_initrd_mem(unsigned long start, unsigned long end)
337 {
338 	if (!keep_initrd)
339 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
340 }
341 
342 static int __init keepinitrd_setup(char *__unused)
343 {
344 	keep_initrd = 1;
345 	return 1;
346 }
347 
348 __setup("keepinitrd", keepinitrd_setup);
349 #endif
350