xref: /openbmc/linux/arch/arm64/mm/init.c (revision 5dcb1015)
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 
43 #include "mm.h"
44 
45 phys_addr_t memstart_addr __read_mostly = 0;
46 
47 #ifdef CONFIG_BLK_DEV_INITRD
48 static int __init early_initrd(char *p)
49 {
50 	unsigned long start, size;
51 	char *endp;
52 
53 	start = memparse(p, &endp);
54 	if (*endp == ',') {
55 		size = memparse(endp + 1, NULL);
56 
57 		initrd_start = (unsigned long)__va(start);
58 		initrd_end = (unsigned long)__va(start + size);
59 	}
60 	return 0;
61 }
62 early_param("initrd", early_initrd);
63 #endif
64 
65 /*
66  * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
67  * currently assumes that for memory starting above 4G, 32-bit devices will
68  * use a DMA offset.
69  */
70 static phys_addr_t max_zone_dma_phys(void)
71 {
72 	phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
73 	return min(offset + (1ULL << 32), memblock_end_of_DRAM());
74 }
75 
76 static void __init zone_sizes_init(unsigned long min, unsigned long max)
77 {
78 	struct memblock_region *reg;
79 	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
80 	unsigned long max_dma = min;
81 
82 	memset(zone_size, 0, sizeof(zone_size));
83 
84 	/* 4GB maximum for 32-bit only capable devices */
85 	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
86 		max_dma = PFN_DOWN(max_zone_dma_phys());
87 		zone_size[ZONE_DMA] = max_dma - min;
88 	}
89 	zone_size[ZONE_NORMAL] = max - max_dma;
90 
91 	memcpy(zhole_size, zone_size, sizeof(zhole_size));
92 
93 	for_each_memblock(memory, reg) {
94 		unsigned long start = memblock_region_memory_base_pfn(reg);
95 		unsigned long end = memblock_region_memory_end_pfn(reg);
96 
97 		if (start >= max)
98 			continue;
99 
100 		if (IS_ENABLED(CONFIG_ZONE_DMA) && start < max_dma) {
101 			unsigned long dma_end = min(end, max_dma);
102 			zhole_size[ZONE_DMA] -= dma_end - start;
103 		}
104 
105 		if (end > max_dma) {
106 			unsigned long normal_end = min(end, max);
107 			unsigned long normal_start = max(start, max_dma);
108 			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
109 		}
110 	}
111 
112 	free_area_init_node(0, zone_size, min, zhole_size);
113 }
114 
115 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
116 int pfn_valid(unsigned long pfn)
117 {
118 	return memblock_is_memory(pfn << PAGE_SHIFT);
119 }
120 EXPORT_SYMBOL(pfn_valid);
121 #endif
122 
123 #ifndef CONFIG_SPARSEMEM
124 static void arm64_memory_present(void)
125 {
126 }
127 #else
128 static void arm64_memory_present(void)
129 {
130 	struct memblock_region *reg;
131 
132 	for_each_memblock(memory, reg)
133 		memory_present(0, memblock_region_memory_base_pfn(reg),
134 			       memblock_region_memory_end_pfn(reg));
135 }
136 #endif
137 
138 void __init arm64_memblock_init(void)
139 {
140 	phys_addr_t dma_phys_limit = 0;
141 
142 	/*
143 	 * Register the kernel text, kernel data, initrd, and initial
144 	 * pagetables with memblock.
145 	 */
146 	memblock_reserve(__pa(_text), _end - _text);
147 #ifdef CONFIG_BLK_DEV_INITRD
148 	if (initrd_start)
149 		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
150 #endif
151 
152 	early_init_fdt_scan_reserved_mem();
153 
154 	/* 4GB maximum for 32-bit only capable devices */
155 	if (IS_ENABLED(CONFIG_ZONE_DMA))
156 		dma_phys_limit = max_zone_dma_phys();
157 	dma_contiguous_reserve(dma_phys_limit);
158 
159 	memblock_allow_resize();
160 	memblock_dump_all();
161 }
162 
163 void __init bootmem_init(void)
164 {
165 	unsigned long min, max;
166 
167 	min = PFN_UP(memblock_start_of_DRAM());
168 	max = PFN_DOWN(memblock_end_of_DRAM());
169 
170 	/*
171 	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
172 	 * done after the fixed reservations.
173 	 */
174 	arm64_memory_present();
175 
176 	sparse_init();
177 	zone_sizes_init(min, max);
178 
179 	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
180 	max_pfn = max_low_pfn = max;
181 }
182 
183 #ifndef CONFIG_SPARSEMEM_VMEMMAP
184 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
185 {
186 	struct page *start_pg, *end_pg;
187 	unsigned long pg, pgend;
188 
189 	/*
190 	 * Convert start_pfn/end_pfn to a struct page pointer.
191 	 */
192 	start_pg = pfn_to_page(start_pfn - 1) + 1;
193 	end_pg = pfn_to_page(end_pfn - 1) + 1;
194 
195 	/*
196 	 * Convert to physical addresses, and round start upwards and end
197 	 * downwards.
198 	 */
199 	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
200 	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
201 
202 	/*
203 	 * If there are free pages between these, free the section of the
204 	 * memmap array.
205 	 */
206 	if (pg < pgend)
207 		free_bootmem(pg, pgend - pg);
208 }
209 
210 /*
211  * The mem_map array can get very big. Free the unused area of the memory map.
212  */
213 static void __init free_unused_memmap(void)
214 {
215 	unsigned long start, prev_end = 0;
216 	struct memblock_region *reg;
217 
218 	for_each_memblock(memory, reg) {
219 		start = __phys_to_pfn(reg->base);
220 
221 #ifdef CONFIG_SPARSEMEM
222 		/*
223 		 * Take care not to free memmap entries that don't exist due
224 		 * to SPARSEMEM sections which aren't present.
225 		 */
226 		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
227 #endif
228 		/*
229 		 * If we had a previous bank, and there is a space between the
230 		 * current bank and the previous, free it.
231 		 */
232 		if (prev_end && prev_end < start)
233 			free_memmap(prev_end, start);
234 
235 		/*
236 		 * Align up here since the VM subsystem insists that the
237 		 * memmap entries are valid from the bank end aligned to
238 		 * MAX_ORDER_NR_PAGES.
239 		 */
240 		prev_end = ALIGN(start + __phys_to_pfn(reg->size),
241 				 MAX_ORDER_NR_PAGES);
242 	}
243 
244 #ifdef CONFIG_SPARSEMEM
245 	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
246 		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
247 #endif
248 }
249 #endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
250 
251 /*
252  * mem_init() marks the free areas in the mem_map and tells us how much memory
253  * is free.  This is done after various parts of the system have claimed their
254  * memory after the kernel image.
255  */
256 void __init mem_init(void)
257 {
258 	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
259 
260 #ifndef CONFIG_SPARSEMEM_VMEMMAP
261 	free_unused_memmap();
262 #endif
263 	/* this will put all unused low memory onto the freelists */
264 	free_all_bootmem();
265 
266 	mem_init_print_info(NULL);
267 
268 #define MLK(b, t) b, t, ((t) - (b)) >> 10
269 #define MLM(b, t) b, t, ((t) - (b)) >> 20
270 #define MLG(b, t) b, t, ((t) - (b)) >> 30
271 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
272 
273 	pr_notice("Virtual kernel memory layout:\n"
274 		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld GB)\n"
275 #ifdef CONFIG_SPARSEMEM_VMEMMAP
276 		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld GB maximum)\n"
277 		  "              0x%16lx - 0x%16lx   (%6ld MB actual)\n"
278 #endif
279 		  "    PCI I/O : 0x%16lx - 0x%16lx   (%6ld MB)\n"
280 		  "    fixed   : 0x%16lx - 0x%16lx   (%6ld KB)\n"
281 		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
282 		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
283 		  "      .init : 0x%p" " - 0x%p" "   (%6ld KB)\n"
284 		  "      .text : 0x%p" " - 0x%p" "   (%6ld KB)\n"
285 		  "      .data : 0x%p" " - 0x%p" "   (%6ld KB)\n",
286 		  MLG(VMALLOC_START, VMALLOC_END),
287 #ifdef CONFIG_SPARSEMEM_VMEMMAP
288 		  MLG((unsigned long)vmemmap,
289 		      (unsigned long)vmemmap + VMEMMAP_SIZE),
290 		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
291 		      (unsigned long)virt_to_page(high_memory)),
292 #endif
293 		  MLM((unsigned long)PCI_IOBASE, (unsigned long)PCI_IOBASE + SZ_16M),
294 		  MLK(FIXADDR_START, FIXADDR_TOP),
295 		  MLM(MODULES_VADDR, MODULES_END),
296 		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
297 		  MLK_ROUNDUP(__init_begin, __init_end),
298 		  MLK_ROUNDUP(_text, _etext),
299 		  MLK_ROUNDUP(_sdata, _edata));
300 
301 #undef MLK
302 #undef MLM
303 #undef MLK_ROUNDUP
304 
305 	/*
306 	 * Check boundaries twice: Some fundamental inconsistencies can be
307 	 * detected at build time already.
308 	 */
309 #ifdef CONFIG_COMPAT
310 	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
311 #endif
312 	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
313 	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
314 
315 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
316 		extern int sysctl_overcommit_memory;
317 		/*
318 		 * On a machine this small we won't get anywhere without
319 		 * overcommit, so turn it on by default.
320 		 */
321 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
322 	}
323 }
324 
325 void free_initmem(void)
326 {
327 	free_initmem_default(0);
328 }
329 
330 #ifdef CONFIG_BLK_DEV_INITRD
331 
332 static int keep_initrd;
333 
334 void free_initrd_mem(unsigned long start, unsigned long end)
335 {
336 	if (!keep_initrd) {
337 		if (start == initrd_start)
338 			start = round_down(start, PAGE_SIZE);
339 		if (end == initrd_end)
340 			end = round_up(end, PAGE_SIZE);
341 
342 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
343 	}
344 }
345 
346 static int __init keepinitrd_setup(char *__unused)
347 {
348 	keep_initrd = 1;
349 	return 1;
350 }
351 
352 __setup("keepinitrd", keepinitrd_setup);
353 #endif
354