summaryrefslogtreecommitdiff
path: root/arch/riscv/mm/init.c
blob: b55be44ff9bdf3ebad11a952b56b366ab2310ed7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
 */

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/swap.h>
#include <linux/sizes.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <linux/set_memory.h>

#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/io.h>

#include "../kernel/head.h"

unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
							__page_aligned_bss;
EXPORT_SYMBOL(empty_zero_page);

extern char _start[];
void *dtb_early_va;

static void __init zone_sizes_init(void)
{
	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };

#ifdef CONFIG_ZONE_DMA32
	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
			(unsigned long) PFN_PHYS(max_low_pfn)));
#endif
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;

	free_area_init_nodes(max_zone_pfns);
}

static void setup_zero_page(void)
{
	memset((void *)empty_zero_page, 0, PAGE_SIZE);
}

#ifdef CONFIG_DEBUG_VM
static inline void print_mlk(char *name, unsigned long b, unsigned long t)
{
	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
		  (((t) - (b)) >> 10));
}

static inline void print_mlm(char *name, unsigned long b, unsigned long t)
{
	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
		  (((t) - (b)) >> 20));
}

static void print_vm_layout(void)
{
	pr_notice("Virtual kernel memory layout:\n");
	print_mlk("fixmap", (unsigned long)FIXADDR_START,
		  (unsigned long)FIXADDR_TOP);
	print_mlm("pci io", (unsigned long)PCI_IO_START,
		  (unsigned long)PCI_IO_END);
	print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
		  (unsigned long)VMEMMAP_END);
	print_mlm("vmalloc", (unsigned long)VMALLOC_START,
		  (unsigned long)VMALLOC_END);
	print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
		  (unsigned long)high_memory);
}
#else
static void print_vm_layout(void) { }
#endif /* CONFIG_DEBUG_VM */

void __init mem_init(void)
{
#ifdef CONFIG_FLATMEM
	BUG_ON(!mem_map);
#endif /* CONFIG_FLATMEM */

	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
	memblock_free_all();

	mem_init_print_info(NULL);
	print_vm_layout();
}

#ifdef CONFIG_BLK_DEV_INITRD
static void __init setup_initrd(void)
{
	unsigned long size;

	if (initrd_start >= initrd_end) {
		pr_info("initrd not found or empty");
		goto disable;
	}
	if (__pa_symbol(initrd_end) > PFN_PHYS(max_low_pfn)) {
		pr_err("initrd extends beyond end of memory");
		goto disable;
	}

	size = initrd_end - initrd_start;
	memblock_reserve(__pa_symbol(initrd_start), size);
	initrd_below_start_ok = 1;

	pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
		(void *)(initrd_start), size);
	return;
disable:
	pr_cont(" - disabling initrd\n");
	initrd_start = 0;
	initrd_end = 0;
}
#endif /* CONFIG_BLK_DEV_INITRD */

static phys_addr_t dtb_early_pa __initdata;

void __init setup_bootmem(void)
{
	struct memblock_region *reg;
	phys_addr_t mem_size = 0;
	phys_addr_t vmlinux_end = __pa_symbol(&_end);
	phys_addr_t vmlinux_start = __pa_symbol(&_start);

	/* Find the memory region containing the kernel */
	for_each_memblock(memory, reg) {
		phys_addr_t end = reg->base + reg->size;

		if (reg->base <= vmlinux_start && vmlinux_end <= end) {
			mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);

			/*
			 * Remove memblock from the end of usable area to the
			 * end of region
			 */
			if (reg->base + mem_size < end)
				memblock_remove(reg->base + mem_size,
						end - reg->base - mem_size);
		}
	}
	BUG_ON(mem_size == 0);

	/* Reserve from the start of the kernel to the end of the kernel */
	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);

	set_max_mapnr(PFN_DOWN(mem_size));
	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());

#ifdef CONFIG_BLK_DEV_INITRD
	setup_initrd();
#endif /* CONFIG_BLK_DEV_INITRD */

	/*
	 * Avoid using early_init_fdt_reserve_self() since __pa() does
	 * not work for DTB pointers that are fixmap addresses
	 */
	memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));

	early_init_fdt_scan_reserved_mem();
	memblock_allow_resize();
	memblock_dump_all();

	for_each_memblock(memory, reg) {
		unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
		unsigned long end_pfn = memblock_region_memory_end_pfn(reg);

		memblock_set_node(PFN_PHYS(start_pfn),
				  PFN_PHYS(end_pfn - start_pfn),
				  &memblock.memory, 0);
	}
}

#ifdef CONFIG_MMU
unsigned long va_pa_offset;
EXPORT_SYMBOL(va_pa_offset);
unsigned long pfn_base;
EXPORT_SYMBOL(pfn_base);

pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
static bool mmu_enabled;

#define MAX_EARLY_MAPPING_SIZE	SZ_128M

pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);

void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
{
	unsigned long addr = __fix_to_virt(idx);
	pte_t *ptep;

	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);

	ptep = &fixmap_pte[pte_index(addr)];

	if (pgprot_val(prot)) {
		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
	} else {
		pte_clear(&init_mm, addr, ptep);
		local_flush_tlb_page(addr);
	}
}

static pte_t *__init get_pte_virt(phys_addr_t pa)
{
	if (mmu_enabled) {
		clear_fixmap(FIX_PTE);
		return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
	} else {
		return (pte_t *)((uintptr_t)pa);
	}
}

static phys_addr_t __init alloc_pte(uintptr_t va)
{
	/*
	 * We only create PMD or PGD early mappings so we
	 * should never reach here with MMU disabled.
	 */
	BUG_ON(!mmu_enabled);

	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
}

static void __init create_pte_mapping(pte_t *ptep,
				      uintptr_t va, phys_addr_t pa,
				      phys_addr_t sz, pgprot_t prot)
{
	uintptr_t pte_index = pte_index(va);

	BUG_ON(sz != PAGE_SIZE);

	if (pte_none(ptep[pte_index]))
		ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot);
}

#ifndef __PAGETABLE_PMD_FOLDED

pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;

#if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
#define NUM_EARLY_PMDS		1UL
#else
#define NUM_EARLY_PMDS		(1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
#endif
pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);

static pmd_t *__init get_pmd_virt(phys_addr_t pa)
{
	if (mmu_enabled) {
		clear_fixmap(FIX_PMD);
		return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
	} else {
		return (pmd_t *)((uintptr_t)pa);
	}
}

static phys_addr_t __init alloc_pmd(uintptr_t va)
{
	uintptr_t pmd_num;

	if (mmu_enabled)
		return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);

	pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
	BUG_ON(pmd_num >= NUM_EARLY_PMDS);
	return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
}

static void __init create_pmd_mapping(pmd_t *pmdp,
				      uintptr_t va, phys_addr_t pa,
				      phys_addr_t sz, pgprot_t prot)
{
	pte_t *ptep;
	phys_addr_t pte_phys;
	uintptr_t pmd_index = pmd_index(va);

	if (sz == PMD_SIZE) {
		if (pmd_none(pmdp[pmd_index]))
			pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot);
		return;
	}

	if (pmd_none(pmdp[pmd_index])) {
		pte_phys = alloc_pte(va);
		pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
		ptep = get_pte_virt(pte_phys);
		memset(ptep, 0, PAGE_SIZE);
	} else {
		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index]));
		ptep = get_pte_virt(pte_phys);
	}

	create_pte_mapping(ptep, va, pa, sz, prot);
}

#define pgd_next_t		pmd_t
#define alloc_pgd_next(__va)	alloc_pmd(__va)
#define get_pgd_next_virt(__pa)	get_pmd_virt(__pa)
#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
#define fixmap_pgd_next		fixmap_pmd
#else
#define pgd_next_t		pte_t
#define alloc_pgd_next(__va)	alloc_pte(__va)
#define get_pgd_next_virt(__pa)	get_pte_virt(__pa)
#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
#define fixmap_pgd_next		fixmap_pte
#endif

static void __init create_pgd_mapping(pgd_t *pgdp,
				      uintptr_t va, phys_addr_t pa,
				      phys_addr_t sz, pgprot_t prot)
{
	pgd_next_t *nextp;
	phys_addr_t next_phys;
	uintptr_t pgd_index = pgd_index(va);

	if (sz == PGDIR_SIZE) {
		if (pgd_val(pgdp[pgd_index]) == 0)
			pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot);
		return;
	}

	if (pgd_val(pgdp[pgd_index]) == 0) {
		next_phys = alloc_pgd_next(va);
		pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
		nextp = get_pgd_next_virt(next_phys);
		memset(nextp, 0, PAGE_SIZE);
	} else {
		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index]));
		nextp = get_pgd_next_virt(next_phys);
	}

	create_pgd_next_mapping(nextp, va, pa, sz, prot);
}

static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
{
	/* Upgrade to PMD_SIZE mappings whenever possible */
	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
		return PAGE_SIZE;

	return PMD_SIZE;
}

/*
 * setup_vm() is called from head.S with MMU-off.
 *
 * Following requirements should be honoured for setup_vm() to work
 * correctly:
 * 1) It should use PC-relative addressing for accessing kernel symbols.
 *    To achieve this we always use GCC cmodel=medany.
 * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
 *    so disable compiler instrumentation when FTRACE is enabled.
 *
 * Currently, the above requirements are honoured by using custom CFLAGS
 * for init.o in mm/Makefile.
 */

#ifndef __riscv_cmodel_medany
#error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
#endif

asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{
	uintptr_t va, end_va;
	uintptr_t load_pa = (uintptr_t)(&_start);
	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
	uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);

	va_pa_offset = PAGE_OFFSET - load_pa;
	pfn_base = PFN_DOWN(load_pa);

	/*
	 * Enforce boot alignment requirements of RV32 and
	 * RV64 by only allowing PMD or PGD mappings.
	 */
	BUG_ON(map_size == PAGE_SIZE);

	/* Sanity check alignment and size */
	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
	BUG_ON((load_pa % map_size) != 0);
	BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);

	/* Setup early PGD for fixmap */
	create_pgd_mapping(early_pg_dir, FIXADDR_START,
			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);

#ifndef __PAGETABLE_PMD_FOLDED
	/* Setup fixmap PMD */
	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
	/* Setup trampoline PGD and PMD */
	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
	create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
			   load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
#else
	/* Setup trampoline PGD */
	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
			   load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
#endif

	/*
	 * Setup early PGD covering entire kernel which will allows
	 * us to reach paging_init(). We map all memory banks later
	 * in setup_vm_final() below.
	 */
	end_va = PAGE_OFFSET + load_sz;
	for (va = PAGE_OFFSET; va < end_va; va += map_size)
		create_pgd_mapping(early_pg_dir, va,
				   load_pa + (va - PAGE_OFFSET),
				   map_size, PAGE_KERNEL_EXEC);

	/* Create fixed mapping for early FDT parsing */
	end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
	for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
		create_pte_mapping(fixmap_pte, va,
				   dtb_pa + (va - __fix_to_virt(FIX_FDT)),
				   PAGE_SIZE, PAGE_KERNEL);

	/* Save pointer to DTB for early FDT parsing */
	dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
	/* Save physical address for memblock reservation */
	dtb_early_pa = dtb_pa;
}

static void __init setup_vm_final(void)
{
	uintptr_t va, map_size;
	phys_addr_t pa, start, end;
	struct memblock_region *reg;

	/* Set mmu_enabled flag */
	mmu_enabled = true;

	/* Setup swapper PGD for fixmap */
	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
			   __pa_symbol(fixmap_pgd_next),
			   PGDIR_SIZE, PAGE_TABLE);

	/* Map all memory banks */
	for_each_memblock(memory, reg) {
		start = reg->base;
		end = start + reg->size;

		if (start >= end)
			break;
		if (memblock_is_nomap(reg))
			continue;
		if (start <= __pa(PAGE_OFFSET) &&
		    __pa(PAGE_OFFSET) < end)
			start = __pa(PAGE_OFFSET);

		map_size = best_map_size(start, end - start);
		for (pa = start; pa < end; pa += map_size) {
			va = (uintptr_t)__va(pa);
			create_pgd_mapping(swapper_pg_dir, va, pa,
					   map_size, PAGE_KERNEL_EXEC);
		}
	}

	/* Clear fixmap PTE and PMD mappings */
	clear_fixmap(FIX_PTE);
	clear_fixmap(FIX_PMD);

	/* Move to swapper page table */
	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
	local_flush_tlb_all();
}

void free_initmem(void)
{
	unsigned long init_begin = (unsigned long)__init_begin;
	unsigned long init_end = (unsigned long)__init_end;

	/* Make the region as non-execuatble. */
	set_memory_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
	free_initmem_default(POISON_FREE_INITMEM);
}

#else
asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{
	dtb_early_va = (void *)dtb_pa;
}

static inline void setup_vm_final(void)
{
}
#endif /* CONFIG_MMU */

#ifdef CONFIG_STRICT_KERNEL_RWX
void set_kernel_text_rw(void)
{
	unsigned long text_start = (unsigned long)_text;
	unsigned long text_end = (unsigned long)_etext;

	set_memory_rw(text_start, (text_end - text_start) >> PAGE_SHIFT);
}

void set_kernel_text_ro(void)
{
	unsigned long text_start = (unsigned long)_text;
	unsigned long text_end = (unsigned long)_etext;

	set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
}

void mark_rodata_ro(void)
{
	unsigned long text_start = (unsigned long)_text;
	unsigned long text_end = (unsigned long)_etext;
	unsigned long rodata_start = (unsigned long)__start_rodata;
	unsigned long data_start = (unsigned long)_data;
	unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));

	set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
	set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
	set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
	set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
}
#endif

void __init paging_init(void)
{
	setup_vm_final();
	memblocks_present();
	sparse_init();
	setup_zero_page();
	zone_sizes_init();
}

#ifdef CONFIG_SPARSEMEM_VMEMMAP
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
			       struct vmem_altmap *altmap)
{
	return vmemmap_populate_basepages(start, end, node);
}
#endif