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#include <linux/swiotlb.h>
37
38#include <asm/fixmap.h>
39#include <asm/memory.h>
40#include <asm/sections.h>
41#include <asm/setup.h>
42#include <asm/sizes.h>
43#include <asm/tlb.h>
44#include <asm/alternative.h>
45
46#include "mm.h"
47
48phys_addr_t memstart_addr __read_mostly = 0;
49phys_addr_t arm64_dma_phys_limit __read_mostly;
50
51#ifdef CONFIG_BLK_DEV_INITRD
52static int __init early_initrd(char *p)
53{
54	unsigned long start, size;
55	char *endp;
56
57	start = memparse(p, &endp);
58	if (*endp == ',') {
59		size = memparse(endp + 1, NULL);
60
61		initrd_start = (unsigned long)__va(start);
62		initrd_end = (unsigned long)__va(start + size);
63	}
64	return 0;
65}
66early_param("initrd", early_initrd);
67#endif
68
69/*
70 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
71 * currently assumes that for memory starting above 4G, 32-bit devices will
72 * use a DMA offset.
73 */
74static phys_addr_t max_zone_dma_phys(void)
75{
76	phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
77	return min(offset + (1ULL << 32), memblock_end_of_DRAM());
78}
79
80static void __init zone_sizes_init(unsigned long min, unsigned long max)
81{
82	struct memblock_region *reg;
83	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
84	unsigned long max_dma = min;
85
86	memset(zone_size, 0, sizeof(zone_size));
87
88	/* 4GB maximum for 32-bit only capable devices */
89#ifdef CONFIG_ZONE_DMA
90	max_dma = PFN_DOWN(arm64_dma_phys_limit);
91	zone_size[ZONE_DMA] = max_dma - min;
92#endif
93	zone_size[ZONE_NORMAL] = max - max_dma;
94
95	memcpy(zhole_size, zone_size, sizeof(zhole_size));
96
97	for_each_memblock(memory, reg) {
98		unsigned long start = memblock_region_memory_base_pfn(reg);
99		unsigned long end = memblock_region_memory_end_pfn(reg);
100
101		if (start >= max)
102			continue;
103
104#ifdef CONFIG_ZONE_DMA
105		if (start < max_dma) {
106			unsigned long dma_end = min(end, max_dma);
107			zhole_size[ZONE_DMA] -= dma_end - start;
108		}
109#endif
110		if (end > max_dma) {
111			unsigned long normal_end = min(end, max);
112			unsigned long normal_start = max(start, max_dma);
113			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
114		}
115	}
116
117	free_area_init_node(0, zone_size, min, zhole_size);
118}
119
120#ifdef CONFIG_HAVE_ARCH_PFN_VALID
121int pfn_valid(unsigned long pfn)
122{
123	return memblock_is_memory(pfn << PAGE_SHIFT);
124}
125EXPORT_SYMBOL(pfn_valid);
126#endif
127
128#ifndef CONFIG_SPARSEMEM
129static void arm64_memory_present(void)
130{
131}
132#else
133static void arm64_memory_present(void)
134{
135	struct memblock_region *reg;
136
137	for_each_memblock(memory, reg)
138		memory_present(0, memblock_region_memory_base_pfn(reg),
139			       memblock_region_memory_end_pfn(reg));
140}
141#endif
142
143static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
144
145/*
146 * Limit the memory size that was specified via FDT.
147 */
148static int __init early_mem(char *p)
149{
150	if (!p)
151		return 1;
152
153	memory_limit = memparse(p, &p) & PAGE_MASK;
154	pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
155
156	return 0;
157}
158early_param("mem", early_mem);
159
160void __init arm64_memblock_init(void)
161{
162	memblock_enforce_memory_limit(memory_limit);
163
164	/*
165	 * Register the kernel text, kernel data, initrd, and initial
166	 * pagetables with memblock.
167	 */
168	memblock_reserve(__pa(_text), _end - _text);
169#ifdef CONFIG_BLK_DEV_INITRD
170	if (initrd_start)
171		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
172#endif
173
174	early_init_fdt_scan_reserved_mem();
175
176	/* 4GB maximum for 32-bit only capable devices */
177	if (IS_ENABLED(CONFIG_ZONE_DMA))
178		arm64_dma_phys_limit = max_zone_dma_phys();
179	else
180		arm64_dma_phys_limit = PHYS_MASK + 1;
181	dma_contiguous_reserve(arm64_dma_phys_limit);
182
183	memblock_allow_resize();
184	memblock_dump_all();
185}
186
187void __init bootmem_init(void)
188{
189	unsigned long min, max;
190
191	min = PFN_UP(memblock_start_of_DRAM());
192	max = PFN_DOWN(memblock_end_of_DRAM());
193
194	early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
195
196	/*
197	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
198	 * done after the fixed reservations.
199	 */
200	arm64_memory_present();
201
202	sparse_init();
203	zone_sizes_init(min, max);
204
205	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
206	max_pfn = max_low_pfn = max;
207}
208
209#ifndef CONFIG_SPARSEMEM_VMEMMAP
210static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
211{
212	struct page *start_pg, *end_pg;
213	unsigned long pg, pgend;
214
215	/*
216	 * Convert start_pfn/end_pfn to a struct page pointer.
217	 */
218	start_pg = pfn_to_page(start_pfn - 1) + 1;
219	end_pg = pfn_to_page(end_pfn - 1) + 1;
220
221	/*
222	 * Convert to physical addresses, and round start upwards and end
223	 * downwards.
224	 */
225	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
226	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
227
228	/*
229	 * If there are free pages between these, free the section of the
230	 * memmap array.
231	 */
232	if (pg < pgend)
233		free_bootmem(pg, pgend - pg);
234}
235
236/*
237 * The mem_map array can get very big. Free the unused area of the memory map.
238 */
239static void __init free_unused_memmap(void)
240{
241	unsigned long start, prev_end = 0;
242	struct memblock_region *reg;
243
244	for_each_memblock(memory, reg) {
245		start = __phys_to_pfn(reg->base);
246
247#ifdef CONFIG_SPARSEMEM
248		/*
249		 * Take care not to free memmap entries that don't exist due
250		 * to SPARSEMEM sections which aren't present.
251		 */
252		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
253#endif
254		/*
255		 * If we had a previous bank, and there is a space between the
256		 * current bank and the previous, free it.
257		 */
258		if (prev_end && prev_end < start)
259			free_memmap(prev_end, start);
260
261		/*
262		 * Align up here since the VM subsystem insists that the
263		 * memmap entries are valid from the bank end aligned to
264		 * MAX_ORDER_NR_PAGES.
265		 */
266		prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
267				 MAX_ORDER_NR_PAGES);
268	}
269
270#ifdef CONFIG_SPARSEMEM
271	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
272		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
273#endif
274}
275#endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
276
277/*
278 * mem_init() marks the free areas in the mem_map and tells us how much memory
279 * is free.  This is done after various parts of the system have claimed their
280 * memory after the kernel image.
281 */
282void __init mem_init(void)
283{
284	swiotlb_init(1);
285
286	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
287
288#ifndef CONFIG_SPARSEMEM_VMEMMAP
289	free_unused_memmap();
290#endif
291	/* this will put all unused low memory onto the freelists */
292	free_all_bootmem();
293
294	mem_init_print_info(NULL);
295
296#define MLK(b, t) b, t, ((t) - (b)) >> 10
297#define MLM(b, t) b, t, ((t) - (b)) >> 20
298#define MLG(b, t) b, t, ((t) - (b)) >> 30
299#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
300
301	pr_notice("Virtual kernel memory layout:\n"
302#ifdef CONFIG_KASAN
303		  "    kasan   : 0x%16lx - 0x%16lx   (%6ld GB)\n"
304#endif
305		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld GB)\n"
306#ifdef CONFIG_SPARSEMEM_VMEMMAP
307		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld GB maximum)\n"
308		  "              0x%16lx - 0x%16lx   (%6ld MB actual)\n"
309#endif
310		  "    fixed   : 0x%16lx - 0x%16lx   (%6ld KB)\n"
311		  "    PCI I/O : 0x%16lx - 0x%16lx   (%6ld MB)\n"
312		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
313		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
314		  "      .init : 0x%p" " - 0x%p" "   (%6ld KB)\n"
315		  "      .text : 0x%p" " - 0x%p" "   (%6ld KB)\n"
316		  "      .data : 0x%p" " - 0x%p" "   (%6ld KB)\n",
317#ifdef CONFIG_KASAN
318		  MLG(KASAN_SHADOW_START, KASAN_SHADOW_END),
319#endif
320		  MLG(VMALLOC_START, VMALLOC_END),
321#ifdef CONFIG_SPARSEMEM_VMEMMAP
322		  MLG(VMEMMAP_START,
323		      VMEMMAP_START + VMEMMAP_SIZE),
324		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
325		      (unsigned long)virt_to_page(high_memory)),
326#endif
327		  MLK(FIXADDR_START, FIXADDR_TOP),
328		  MLM(PCI_IO_START, PCI_IO_END),
329		  MLM(MODULES_VADDR, MODULES_END),
330		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
331		  MLK_ROUNDUP(__init_begin, __init_end),
332		  MLK_ROUNDUP(_text, _etext),
333		  MLK_ROUNDUP(_sdata, _edata));
334
335#undef MLK
336#undef MLM
337#undef MLK_ROUNDUP
338
339	/*
340	 * Check boundaries twice: Some fundamental inconsistencies can be
341	 * detected at build time already.
342	 */
343#ifdef CONFIG_COMPAT
344	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
345#endif
346	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
347	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
348
349	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
350		extern int sysctl_overcommit_memory;
351		/*
352		 * On a machine this small we won't get anywhere without
353		 * overcommit, so turn it on by default.
354		 */
355		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
356	}
357}
358
359void free_initmem(void)
360{
361	fixup_init();
362	free_initmem_default(0);
363	free_alternatives_memory();
364}
365
366#ifdef CONFIG_BLK_DEV_INITRD
367
368static int keep_initrd __initdata;
369
370void __init free_initrd_mem(unsigned long start, unsigned long end)
371{
372	if (!keep_initrd)
373		free_reserved_area((void *)start, (void *)end, 0, "initrd");
374}
375
376static int __init keepinitrd_setup(char *__unused)
377{
378	keep_initrd = 1;
379	return 1;
380}
381
382__setup("keepinitrd", keepinitrd_setup);
383#endif
384