1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2012 Regents of the University of California
4 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
5 */
6
7 #include <linux/init.h>
8 #include <linux/mm.h>
9 #include <linux/memblock.h>
10 #include <linux/initrd.h>
11 #include <linux/swap.h>
12 #include <linux/sizes.h>
13 #include <linux/of_fdt.h>
14 #include <linux/libfdt.h>
15
16 #include <asm/fixmap.h>
17 #include <asm/tlbflush.h>
18 #include <asm/sections.h>
19 #include <asm/pgtable.h>
20 #include <asm/io.h>
21
22 #include "../kernel/head.h"
23
24 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
25 __page_aligned_bss;
26 EXPORT_SYMBOL(empty_zero_page);
27
28 extern char _start[];
29
zone_sizes_init(void)30 static void __init zone_sizes_init(void)
31 {
32 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
33
34 #ifdef CONFIG_ZONE_DMA32
35 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
36 (unsigned long) PFN_PHYS(max_low_pfn)));
37 #endif
38 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
39
40 free_area_init_nodes(max_zone_pfns);
41 }
42
setup_zero_page(void)43 void setup_zero_page(void)
44 {
45 memset((void *)empty_zero_page, 0, PAGE_SIZE);
46 }
47
mem_init(void)48 void __init mem_init(void)
49 {
50 #ifdef CONFIG_FLATMEM
51 BUG_ON(!mem_map);
52 #endif /* CONFIG_FLATMEM */
53
54 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
55 memblock_free_all();
56
57 mem_init_print_info(NULL);
58 }
59
60 #ifdef CONFIG_BLK_DEV_INITRD
setup_initrd(void)61 static void __init setup_initrd(void)
62 {
63 unsigned long size;
64
65 if (initrd_start >= initrd_end) {
66 pr_info("initrd not found or empty");
67 goto disable;
68 }
69 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
70 pr_err("initrd extends beyond end of memory");
71 goto disable;
72 }
73
74 size = initrd_end - initrd_start;
75 memblock_reserve(__pa(initrd_start), size);
76 initrd_below_start_ok = 1;
77
78 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
79 (void *)(initrd_start), size);
80 return;
81 disable:
82 pr_cont(" - disabling initrd\n");
83 initrd_start = 0;
84 initrd_end = 0;
85 }
86 #endif /* CONFIG_BLK_DEV_INITRD */
87
88 static phys_addr_t dtb_early_pa __initdata;
89
setup_bootmem(void)90 void __init setup_bootmem(void)
91 {
92 struct memblock_region *reg;
93 phys_addr_t mem_size = 0;
94 phys_addr_t vmlinux_end = __pa(&_end);
95 phys_addr_t vmlinux_start = __pa(&_start);
96
97 /* Find the memory region containing the kernel */
98 for_each_memblock(memory, reg) {
99 phys_addr_t end = reg->base + reg->size;
100
101 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
102 mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
103
104 /*
105 * Remove memblock from the end of usable area to the
106 * end of region
107 */
108 if (reg->base + mem_size < end)
109 memblock_remove(reg->base + mem_size,
110 end - reg->base - mem_size);
111 }
112 }
113 BUG_ON(mem_size == 0);
114
115 /* Reserve from the start of the kernel to the end of the kernel */
116 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
117
118 set_max_mapnr(PFN_DOWN(mem_size));
119 max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
120
121 #ifdef CONFIG_BLK_DEV_INITRD
122 setup_initrd();
123 #endif /* CONFIG_BLK_DEV_INITRD */
124
125 /*
126 * Avoid using early_init_fdt_reserve_self() since __pa() does
127 * not work for DTB pointers that are fixmap addresses
128 */
129 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
130
131 early_init_fdt_scan_reserved_mem();
132 memblock_allow_resize();
133 memblock_dump_all();
134
135 for_each_memblock(memory, reg) {
136 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
137 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
138
139 memblock_set_node(PFN_PHYS(start_pfn),
140 PFN_PHYS(end_pfn - start_pfn),
141 &memblock.memory, 0);
142 }
143 }
144
145 unsigned long va_pa_offset;
146 EXPORT_SYMBOL(va_pa_offset);
147 unsigned long pfn_base;
148 EXPORT_SYMBOL(pfn_base);
149
150 void *dtb_early_va;
151 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
152 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
153 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
154 static bool mmu_enabled;
155
156 #define MAX_EARLY_MAPPING_SIZE SZ_128M
157
158 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
159
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t prot)160 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
161 {
162 unsigned long addr = __fix_to_virt(idx);
163 pte_t *ptep;
164
165 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
166
167 ptep = &fixmap_pte[pte_index(addr)];
168
169 if (pgprot_val(prot)) {
170 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
171 } else {
172 pte_clear(&init_mm, addr, ptep);
173 local_flush_tlb_page(addr);
174 }
175 }
176
get_pte_virt(phys_addr_t pa)177 static pte_t *__init get_pte_virt(phys_addr_t pa)
178 {
179 if (mmu_enabled) {
180 clear_fixmap(FIX_PTE);
181 return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
182 } else {
183 return (pte_t *)((uintptr_t)pa);
184 }
185 }
186
alloc_pte(uintptr_t va)187 static phys_addr_t __init alloc_pte(uintptr_t va)
188 {
189 /*
190 * We only create PMD or PGD early mappings so we
191 * should never reach here with MMU disabled.
192 */
193 BUG_ON(!mmu_enabled);
194
195 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
196 }
197
create_pte_mapping(pte_t * ptep,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)198 static void __init create_pte_mapping(pte_t *ptep,
199 uintptr_t va, phys_addr_t pa,
200 phys_addr_t sz, pgprot_t prot)
201 {
202 uintptr_t pte_index = pte_index(va);
203
204 BUG_ON(sz != PAGE_SIZE);
205
206 if (pte_none(ptep[pte_index]))
207 ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot);
208 }
209
210 #ifndef __PAGETABLE_PMD_FOLDED
211
212 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
213 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
214
215 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
216 #define NUM_EARLY_PMDS 1UL
217 #else
218 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
219 #endif
220 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
221
get_pmd_virt(phys_addr_t pa)222 static pmd_t *__init get_pmd_virt(phys_addr_t pa)
223 {
224 if (mmu_enabled) {
225 clear_fixmap(FIX_PMD);
226 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
227 } else {
228 return (pmd_t *)((uintptr_t)pa);
229 }
230 }
231
alloc_pmd(uintptr_t va)232 static phys_addr_t __init alloc_pmd(uintptr_t va)
233 {
234 uintptr_t pmd_num;
235
236 if (mmu_enabled)
237 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
238
239 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
240 BUG_ON(pmd_num >= NUM_EARLY_PMDS);
241 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
242 }
243
create_pmd_mapping(pmd_t * pmdp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)244 static void __init create_pmd_mapping(pmd_t *pmdp,
245 uintptr_t va, phys_addr_t pa,
246 phys_addr_t sz, pgprot_t prot)
247 {
248 pte_t *ptep;
249 phys_addr_t pte_phys;
250 uintptr_t pmd_index = pmd_index(va);
251
252 if (sz == PMD_SIZE) {
253 if (pmd_none(pmdp[pmd_index]))
254 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot);
255 return;
256 }
257
258 if (pmd_none(pmdp[pmd_index])) {
259 pte_phys = alloc_pte(va);
260 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
261 ptep = get_pte_virt(pte_phys);
262 memset(ptep, 0, PAGE_SIZE);
263 } else {
264 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index]));
265 ptep = get_pte_virt(pte_phys);
266 }
267
268 create_pte_mapping(ptep, va, pa, sz, prot);
269 }
270
271 #define pgd_next_t pmd_t
272 #define alloc_pgd_next(__va) alloc_pmd(__va)
273 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa)
274 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
275 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
276 #define PTE_PARENT_SIZE PMD_SIZE
277 #define fixmap_pgd_next fixmap_pmd
278 #else
279 #define pgd_next_t pte_t
280 #define alloc_pgd_next(__va) alloc_pte(__va)
281 #define get_pgd_next_virt(__pa) get_pte_virt(__pa)
282 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
283 create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
284 #define PTE_PARENT_SIZE PGDIR_SIZE
285 #define fixmap_pgd_next fixmap_pte
286 #endif
287
create_pgd_mapping(pgd_t * pgdp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)288 static void __init create_pgd_mapping(pgd_t *pgdp,
289 uintptr_t va, phys_addr_t pa,
290 phys_addr_t sz, pgprot_t prot)
291 {
292 pgd_next_t *nextp;
293 phys_addr_t next_phys;
294 uintptr_t pgd_index = pgd_index(va);
295
296 if (sz == PGDIR_SIZE) {
297 if (pgd_val(pgdp[pgd_index]) == 0)
298 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot);
299 return;
300 }
301
302 if (pgd_val(pgdp[pgd_index]) == 0) {
303 next_phys = alloc_pgd_next(va);
304 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
305 nextp = get_pgd_next_virt(next_phys);
306 memset(nextp, 0, PAGE_SIZE);
307 } else {
308 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index]));
309 nextp = get_pgd_next_virt(next_phys);
310 }
311
312 create_pgd_next_mapping(nextp, va, pa, sz, prot);
313 }
314
best_map_size(phys_addr_t base,phys_addr_t size)315 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
316 {
317 uintptr_t map_size = PAGE_SIZE;
318
319 /* Upgrade to PMD/PGDIR mappings whenever possible */
320 if (!(base & (PTE_PARENT_SIZE - 1)) &&
321 !(size & (PTE_PARENT_SIZE - 1)))
322 map_size = PTE_PARENT_SIZE;
323
324 return map_size;
325 }
326
327 /*
328 * setup_vm() is called from head.S with MMU-off.
329 *
330 * Following requirements should be honoured for setup_vm() to work
331 * correctly:
332 * 1) It should use PC-relative addressing for accessing kernel symbols.
333 * To achieve this we always use GCC cmodel=medany.
334 * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
335 * so disable compiler instrumentation when FTRACE is enabled.
336 *
337 * Currently, the above requirements are honoured by using custom CFLAGS
338 * for init.o in mm/Makefile.
339 */
340
341 #ifndef __riscv_cmodel_medany
342 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
343 #endif
344
setup_vm(uintptr_t dtb_pa)345 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
346 {
347 uintptr_t va, end_va;
348 uintptr_t load_pa = (uintptr_t)(&_start);
349 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
350 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
351
352 va_pa_offset = PAGE_OFFSET - load_pa;
353 pfn_base = PFN_DOWN(load_pa);
354
355 /*
356 * Enforce boot alignment requirements of RV32 and
357 * RV64 by only allowing PMD or PGD mappings.
358 */
359 BUG_ON(map_size == PAGE_SIZE);
360
361 /* Sanity check alignment and size */
362 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
363 BUG_ON((load_pa % map_size) != 0);
364 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
365
366 /* Setup early PGD for fixmap */
367 create_pgd_mapping(early_pg_dir, FIXADDR_START,
368 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
369
370 #ifndef __PAGETABLE_PMD_FOLDED
371 /* Setup fixmap PMD */
372 create_pmd_mapping(fixmap_pmd, FIXADDR_START,
373 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
374 /* Setup trampoline PGD and PMD */
375 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
376 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
377 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
378 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
379 #else
380 /* Setup trampoline PGD */
381 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
382 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
383 #endif
384
385 /*
386 * Setup early PGD covering entire kernel which will allows
387 * us to reach paging_init(). We map all memory banks later
388 * in setup_vm_final() below.
389 */
390 end_va = PAGE_OFFSET + load_sz;
391 for (va = PAGE_OFFSET; va < end_va; va += map_size)
392 create_pgd_mapping(early_pg_dir, va,
393 load_pa + (va - PAGE_OFFSET),
394 map_size, PAGE_KERNEL_EXEC);
395
396 /* Create fixed mapping for early FDT parsing */
397 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
398 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
399 create_pte_mapping(fixmap_pte, va,
400 dtb_pa + (va - __fix_to_virt(FIX_FDT)),
401 PAGE_SIZE, PAGE_KERNEL);
402
403 /* Save pointer to DTB for early FDT parsing */
404 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
405 /* Save physical address for memblock reservation */
406 dtb_early_pa = dtb_pa;
407 }
408
setup_vm_final(void)409 static void __init setup_vm_final(void)
410 {
411 uintptr_t va, map_size;
412 phys_addr_t pa, start, end;
413 struct memblock_region *reg;
414
415 /* Set mmu_enabled flag */
416 mmu_enabled = true;
417
418 /* Setup swapper PGD for fixmap */
419 create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
420 __pa(fixmap_pgd_next),
421 PGDIR_SIZE, PAGE_TABLE);
422
423 /* Map all memory banks */
424 for_each_memblock(memory, reg) {
425 start = reg->base;
426 end = start + reg->size;
427
428 if (start >= end)
429 break;
430 if (memblock_is_nomap(reg))
431 continue;
432 if (start <= __pa(PAGE_OFFSET) &&
433 __pa(PAGE_OFFSET) < end)
434 start = __pa(PAGE_OFFSET);
435
436 map_size = best_map_size(start, end - start);
437 for (pa = start; pa < end; pa += map_size) {
438 va = (uintptr_t)__va(pa);
439 create_pgd_mapping(swapper_pg_dir, va, pa,
440 map_size, PAGE_KERNEL_EXEC);
441 }
442 }
443
444 /* Clear fixmap PTE and PMD mappings */
445 clear_fixmap(FIX_PTE);
446 clear_fixmap(FIX_PMD);
447
448 /* Move to swapper page table */
449 csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE);
450 local_flush_tlb_all();
451 }
452
paging_init(void)453 void __init paging_init(void)
454 {
455 setup_vm_final();
456 memblocks_present();
457 sparse_init();
458 setup_zero_page();
459 zone_sizes_init();
460 }
461
462 #ifdef CONFIG_SPARSEMEM_VMEMMAP
vmemmap_populate(unsigned long start,unsigned long end,int node,struct vmem_altmap * altmap)463 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
464 struct vmem_altmap *altmap)
465 {
466 return vmemmap_populate_basepages(start, end, node);
467 }
468 #endif
469
