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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * This file contains the routines setting up the linux page tables.
4 * -- paulus
5 *
6 * Derived from arch/ppc/mm/init.c:
7 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
8 *
9 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
10 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
11 * Copyright (C) 1996 Paul Mackerras
12 *
13 * Derived from "arch/i386/mm/init.c"
14 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
15 */
16
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/mm.h>
21#include <linux/vmalloc.h>
22#include <linux/init.h>
23#include <linux/highmem.h>
24#include <linux/memblock.h>
25#include <linux/slab.h>
26#include <linux/set_memory.h>
27
28#include <asm/pgalloc.h>
29#include <asm/fixmap.h>
30#include <asm/setup.h>
31#include <asm/sections.h>
32#include <asm/early_ioremap.h>
33
34#include <mm/mmu_decl.h>
35
36static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data;
37
38notrace void __init early_ioremap_init(void)
39{
40 unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE);
41 pte_t *ptep = (pte_t *)early_fixmap_pagetable;
42 pmd_t *pmdp = pmd_off_k(addr);
43
44 for (; (s32)(FIXADDR_TOP - addr) > 0;
45 addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++)
46 pmd_populate_kernel(&init_mm, pmdp, ptep);
47
48 early_ioremap_setup();
49}
50
51static void __init *early_alloc_pgtable(unsigned long size)
52{
53 void *ptr = memblock_alloc(size, size);
54
55 if (!ptr)
56 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
57 __func__, size, size);
58
59 return ptr;
60}
61
62pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va)
63{
64 if (pmd_none(*pmdp)) {
65 pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
66
67 pmd_populate_kernel(&init_mm, pmdp, ptep);
68 }
69 return pte_offset_kernel(pmdp, va);
70}
71
72
73int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
74{
75 pmd_t *pd;
76 pte_t *pg;
77 int err = -ENOMEM;
78
79 /* Use upper 10 bits of VA to index the first level map */
80 pd = pmd_off_k(va);
81 /* Use middle 10 bits of VA to index the second-level map */
82 if (likely(slab_is_available()))
83 pg = pte_alloc_kernel(pd, va);
84 else
85 pg = early_pte_alloc_kernel(pd, va);
86 if (pg) {
87 err = 0;
88 /* The PTE should never be already set nor present in the
89 * hash table
90 */
91 BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
92 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
93 }
94 smp_wmb();
95 return err;
96}
97
98/*
99 * Map in a chunk of physical memory starting at start.
100 */
101static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
102{
103 unsigned long v, s;
104 phys_addr_t p;
105 bool ktext;
106
107 s = offset;
108 v = PAGE_OFFSET + s;
109 p = memstart_addr + s;
110 for (; s < top; s += PAGE_SIZE) {
111 ktext = core_kernel_text(v);
112 map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
113 v += PAGE_SIZE;
114 p += PAGE_SIZE;
115 }
116}
117
118void __init mapin_ram(void)
119{
120 phys_addr_t base, end;
121 u64 i;
122
123 for_each_mem_range(i, &base, &end) {
124 phys_addr_t top = min(end, total_lowmem);
125
126 if (base >= top)
127 continue;
128 base = mmu_mapin_ram(base, top);
129 __mapin_ram_chunk(base, top);
130 }
131}
132
133void mark_initmem_nx(void)
134{
135 unsigned long numpages = PFN_UP((unsigned long)_einittext) -
136 PFN_DOWN((unsigned long)_sinittext);
137
138 mmu_mark_initmem_nx();
139
140 if (!v_block_mapped((unsigned long)_sinittext)) {
141 set_memory_nx((unsigned long)_sinittext, numpages);
142 set_memory_rw((unsigned long)_sinittext, numpages);
143 }
144}
145
146#ifdef CONFIG_STRICT_KERNEL_RWX
147void mark_rodata_ro(void)
148{
149 unsigned long numpages;
150
151 if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && mmu_has_feature(MMU_FTR_HPTE_TABLE))
152 pr_warn("This platform has HASH MMU, STRICT_MODULE_RWX won't work\n");
153
154 if (v_block_mapped((unsigned long)_stext + 1)) {
155 mmu_mark_rodata_ro();
156 ptdump_check_wx();
157 return;
158 }
159
160 /*
161 * mark text and rodata as read only. __end_rodata is set by
162 * powerpc's linker script and includes tables and data
163 * requiring relocation which are not put in RO_DATA.
164 */
165 numpages = PFN_UP((unsigned long)__end_rodata) -
166 PFN_DOWN((unsigned long)_stext);
167
168 set_memory_ro((unsigned long)_stext, numpages);
169
170 // mark_initmem_nx() should have already run by now
171 ptdump_check_wx();
172}
173#endif
174
175#if defined(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && defined(CONFIG_DEBUG_PAGEALLOC)
176void __kernel_map_pages(struct page *page, int numpages, int enable)
177{
178 unsigned long addr = (unsigned long)page_address(page);
179
180 if (PageHighMem(page))
181 return;
182
183 if (enable)
184 set_memory_p(addr, numpages);
185 else
186 set_memory_np(addr, numpages);
187}
188#endif /* CONFIG_DEBUG_PAGEALLOC */
1/*
2 * This file contains the routines setting up the linux page tables.
3 * -- paulus
4 *
5 * Derived from arch/ppc/mm/init.c:
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 *
8 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
9 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
10 * Copyright (C) 1996 Paul Mackerras
11 *
12 * Derived from "arch/i386/mm/init.c"
13 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 *
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/types.h>
25#include <linux/mm.h>
26#include <linux/vmalloc.h>
27#include <linux/init.h>
28#include <linux/highmem.h>
29#include <linux/memblock.h>
30#include <linux/slab.h>
31
32#include <asm/pgtable.h>
33#include <asm/pgalloc.h>
34#include <asm/fixmap.h>
35#include <asm/io.h>
36#include <asm/setup.h>
37
38#include "mmu_decl.h"
39
40unsigned long ioremap_bot;
41EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
42
43extern char etext[], _stext[], _sinittext[], _einittext[];
44
45#define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT)
46
47#ifndef CONFIG_PPC_4K_PAGES
48static struct kmem_cache *pgtable_cache;
49
50void pgtable_cache_init(void)
51{
52 pgtable_cache = kmem_cache_create("PGDIR cache", 1 << PGDIR_ORDER,
53 1 << PGDIR_ORDER, 0, NULL);
54 if (pgtable_cache == NULL)
55 panic("Couldn't allocate pgtable caches");
56}
57#endif
58
59pgd_t *pgd_alloc(struct mm_struct *mm)
60{
61 pgd_t *ret;
62
63 /* pgdir take page or two with 4K pages and a page fraction otherwise */
64#ifndef CONFIG_PPC_4K_PAGES
65 ret = kmem_cache_alloc(pgtable_cache, GFP_KERNEL | __GFP_ZERO);
66#else
67 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
68 PGDIR_ORDER - PAGE_SHIFT);
69#endif
70 return ret;
71}
72
73void pgd_free(struct mm_struct *mm, pgd_t *pgd)
74{
75#ifndef CONFIG_PPC_4K_PAGES
76 kmem_cache_free(pgtable_cache, (void *)pgd);
77#else
78 free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT);
79#endif
80}
81
82__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
83{
84 pte_t *pte;
85
86 if (slab_is_available()) {
87 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
88 } else {
89 pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
90 if (pte)
91 clear_page(pte);
92 }
93 return pte;
94}
95
96pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
97{
98 struct page *ptepage;
99
100 gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO;
101
102 ptepage = alloc_pages(flags, 0);
103 if (!ptepage)
104 return NULL;
105 if (!pgtable_page_ctor(ptepage)) {
106 __free_page(ptepage);
107 return NULL;
108 }
109 return ptepage;
110}
111
112void __iomem *
113ioremap(phys_addr_t addr, unsigned long size)
114{
115 return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED,
116 __builtin_return_address(0));
117}
118EXPORT_SYMBOL(ioremap);
119
120void __iomem *
121ioremap_wc(phys_addr_t addr, unsigned long size)
122{
123 return __ioremap_caller(addr, size, _PAGE_NO_CACHE,
124 __builtin_return_address(0));
125}
126EXPORT_SYMBOL(ioremap_wc);
127
128void __iomem *
129ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
130{
131 /* writeable implies dirty for kernel addresses */
132 if ((flags & (_PAGE_RW | _PAGE_RO)) != _PAGE_RO)
133 flags |= _PAGE_DIRTY | _PAGE_HWWRITE;
134
135 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
136 flags &= ~(_PAGE_USER | _PAGE_EXEC);
137
138#ifdef _PAGE_BAP_SR
139 /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
140 * which means that we just cleared supervisor access... oops ;-) This
141 * restores it
142 */
143 flags |= _PAGE_BAP_SR;
144#endif
145
146 return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
147}
148EXPORT_SYMBOL(ioremap_prot);
149
150void __iomem *
151__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
152{
153 return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
154}
155
156void __iomem *
157__ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
158 void *caller)
159{
160 unsigned long v, i;
161 phys_addr_t p;
162 int err;
163
164 /* Make sure we have the base flags */
165 if ((flags & _PAGE_PRESENT) == 0)
166 flags |= pgprot_val(PAGE_KERNEL);
167
168 /* Non-cacheable page cannot be coherent */
169 if (flags & _PAGE_NO_CACHE)
170 flags &= ~_PAGE_COHERENT;
171
172 /*
173 * Choose an address to map it to.
174 * Once the vmalloc system is running, we use it.
175 * Before then, we use space going down from IOREMAP_TOP
176 * (ioremap_bot records where we're up to).
177 */
178 p = addr & PAGE_MASK;
179 size = PAGE_ALIGN(addr + size) - p;
180
181 /*
182 * If the address lies within the first 16 MB, assume it's in ISA
183 * memory space
184 */
185 if (p < 16*1024*1024)
186 p += _ISA_MEM_BASE;
187
188#ifndef CONFIG_CRASH_DUMP
189 /*
190 * Don't allow anybody to remap normal RAM that we're using.
191 * mem_init() sets high_memory so only do the check after that.
192 */
193 if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
194 !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
195 printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
196 (unsigned long long)p, __builtin_return_address(0));
197 return NULL;
198 }
199#endif
200
201 if (size == 0)
202 return NULL;
203
204 /*
205 * Is it already mapped? Perhaps overlapped by a previous
206 * mapping.
207 */
208 v = p_block_mapped(p);
209 if (v)
210 goto out;
211
212 if (slab_is_available()) {
213 struct vm_struct *area;
214 area = get_vm_area_caller(size, VM_IOREMAP, caller);
215 if (area == 0)
216 return NULL;
217 area->phys_addr = p;
218 v = (unsigned long) area->addr;
219 } else {
220 v = (ioremap_bot -= size);
221 }
222
223 /*
224 * Should check if it is a candidate for a BAT mapping
225 */
226
227 err = 0;
228 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
229 err = map_page(v+i, p+i, flags);
230 if (err) {
231 if (slab_is_available())
232 vunmap((void *)v);
233 return NULL;
234 }
235
236out:
237 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
238}
239EXPORT_SYMBOL(__ioremap);
240
241void iounmap(volatile void __iomem *addr)
242{
243 /*
244 * If mapped by BATs then there is nothing to do.
245 * Calling vfree() generates a benign warning.
246 */
247 if (v_block_mapped((unsigned long)addr))
248 return;
249
250 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
251 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
252}
253EXPORT_SYMBOL(iounmap);
254
255int map_page(unsigned long va, phys_addr_t pa, int flags)
256{
257 pmd_t *pd;
258 pte_t *pg;
259 int err = -ENOMEM;
260
261 /* Use upper 10 bits of VA to index the first level map */
262 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
263 /* Use middle 10 bits of VA to index the second-level map */
264 pg = pte_alloc_kernel(pd, va);
265 if (pg != 0) {
266 err = 0;
267 /* The PTE should never be already set nor present in the
268 * hash table
269 */
270 BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) &&
271 flags);
272 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
273 __pgprot(flags)));
274 }
275 smp_wmb();
276 return err;
277}
278
279/*
280 * Map in a chunk of physical memory starting at start.
281 */
282void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
283{
284 unsigned long v, s, f;
285 phys_addr_t p;
286 int ktext;
287
288 s = offset;
289 v = PAGE_OFFSET + s;
290 p = memstart_addr + s;
291 for (; s < top; s += PAGE_SIZE) {
292 ktext = ((char *)v >= _stext && (char *)v < etext) ||
293 ((char *)v >= _sinittext && (char *)v < _einittext);
294 f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL);
295 map_page(v, p, f);
296#ifdef CONFIG_PPC_STD_MMU_32
297 if (ktext)
298 hash_preload(&init_mm, v, 0, 0x300);
299#endif
300 v += PAGE_SIZE;
301 p += PAGE_SIZE;
302 }
303}
304
305void __init mapin_ram(void)
306{
307 unsigned long s, top;
308
309#ifndef CONFIG_WII
310 top = total_lowmem;
311 s = mmu_mapin_ram(top);
312 __mapin_ram_chunk(s, top);
313#else
314 if (!wii_hole_size) {
315 s = mmu_mapin_ram(total_lowmem);
316 __mapin_ram_chunk(s, total_lowmem);
317 } else {
318 top = wii_hole_start;
319 s = mmu_mapin_ram(top);
320 __mapin_ram_chunk(s, top);
321
322 top = memblock_end_of_DRAM();
323 s = wii_mmu_mapin_mem2(top);
324 __mapin_ram_chunk(s, top);
325 }
326#endif
327}
328
329/* Scan the real Linux page tables and return a PTE pointer for
330 * a virtual address in a context.
331 * Returns true (1) if PTE was found, zero otherwise. The pointer to
332 * the PTE pointer is unmodified if PTE is not found.
333 */
334int
335get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
336{
337 pgd_t *pgd;
338 pud_t *pud;
339 pmd_t *pmd;
340 pte_t *pte;
341 int retval = 0;
342
343 pgd = pgd_offset(mm, addr & PAGE_MASK);
344 if (pgd) {
345 pud = pud_offset(pgd, addr & PAGE_MASK);
346 if (pud && pud_present(*pud)) {
347 pmd = pmd_offset(pud, addr & PAGE_MASK);
348 if (pmd_present(*pmd)) {
349 pte = pte_offset_map(pmd, addr & PAGE_MASK);
350 if (pte) {
351 retval = 1;
352 *ptep = pte;
353 if (pmdp)
354 *pmdp = pmd;
355 /* XXX caller needs to do pte_unmap, yuck */
356 }
357 }
358 }
359 }
360 return(retval);
361}
362
363#ifdef CONFIG_DEBUG_PAGEALLOC
364
365static int __change_page_attr(struct page *page, pgprot_t prot)
366{
367 pte_t *kpte;
368 pmd_t *kpmd;
369 unsigned long address;
370
371 BUG_ON(PageHighMem(page));
372 address = (unsigned long)page_address(page);
373
374 if (v_block_mapped(address))
375 return 0;
376 if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
377 return -EINVAL;
378 __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
379 wmb();
380 flush_tlb_page(NULL, address);
381 pte_unmap(kpte);
382
383 return 0;
384}
385
386/*
387 * Change the page attributes of an page in the linear mapping.
388 *
389 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
390 */
391static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
392{
393 int i, err = 0;
394 unsigned long flags;
395
396 local_irq_save(flags);
397 for (i = 0; i < numpages; i++, page++) {
398 err = __change_page_attr(page, prot);
399 if (err)
400 break;
401 }
402 local_irq_restore(flags);
403 return err;
404}
405
406
407void __kernel_map_pages(struct page *page, int numpages, int enable)
408{
409 if (PageHighMem(page))
410 return;
411
412 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
413}
414#endif /* CONFIG_DEBUG_PAGEALLOC */
415
416static int fixmaps;
417
418void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
419{
420 unsigned long address = __fix_to_virt(idx);
421
422 if (idx >= __end_of_fixed_addresses) {
423 BUG();
424 return;
425 }
426
427 map_page(address, phys, pgprot_val(flags));
428 fixmaps++;
429}
430
431void __this_fixmap_does_not_exist(void)
432{
433 WARN_ON(1);
434}