1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5 #include <linux/init.h>
6 #include <linux/export.h>
7 #include <linux/signal.h>
8 #include <linux/sched.h>
9 #include <linux/smp.h>
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/string.h>
13 #include <linux/types.h>
14 #include <linux/pagemap.h>
15 #include <linux/memblock.h>
16 #include <linux/memremap.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/highmem.h>
20 #include <linux/swap.h>
21 #include <linux/proc_fs.h>
22 #include <linux/pfn.h>
23 #include <linux/hardirq.h>
24 #include <linux/gfp.h>
25 #include <linux/hugetlb.h>
26 #include <linux/mmzone.h>
27
28 #include <asm/asm-offsets.h>
29 #include <asm/bootinfo.h>
30 #include <asm/cpu.h>
31 #include <asm/dma.h>
32 #include <asm/mmu_context.h>
33 #include <asm/sections.h>
34 #include <asm/pgtable.h>
35 #include <asm/pgalloc.h>
36 #include <asm/tlb.h>
37
38 /*
39 * We have up to 8 empty zeroed pages so we can map one of the right colour
40 * when needed. Since page is never written to after the initialization we
41 * don't have to care about aliases on other CPUs.
42 */
43 unsigned long empty_zero_page, zero_page_mask;
44 EXPORT_SYMBOL_GPL(empty_zero_page);
45 EXPORT_SYMBOL(zero_page_mask);
46
setup_zero_pages(void)47 void setup_zero_pages(void)
48 {
49 unsigned int order, i;
50 struct page *page;
51
52 order = 0;
53
54 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
55 if (!empty_zero_page)
56 panic("Oh boy, that early out of memory?");
57
58 page = virt_to_page((void *)empty_zero_page);
59 split_page(page, order);
60 for (i = 0; i < (1 << order); i++, page++)
61 mark_page_reserved(page);
62
63 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
64 }
65
copy_user_highpage(struct page * to,struct page * from,unsigned long vaddr,struct vm_area_struct * vma)66 void copy_user_highpage(struct page *to, struct page *from,
67 unsigned long vaddr, struct vm_area_struct *vma)
68 {
69 void *vfrom, *vto;
70
71 vto = kmap_atomic(to);
72 vfrom = kmap_atomic(from);
73 copy_page(vto, vfrom);
74 kunmap_atomic(vfrom);
75 kunmap_atomic(vto);
76 /* Make sure this page is cleared on other CPU's too before using it */
77 smp_wmb();
78 }
79
page_is_ram(unsigned long pfn)80 int __ref page_is_ram(unsigned long pfn)
81 {
82 unsigned long addr = PFN_PHYS(pfn);
83
84 return memblock_is_memory(addr) && !memblock_is_reserved(addr);
85 }
86
87 #ifndef CONFIG_NUMA
paging_init(void)88 void __init paging_init(void)
89 {
90 unsigned long max_zone_pfns[MAX_NR_ZONES];
91
92 #ifdef CONFIG_ZONE_DMA
93 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
94 #endif
95 #ifdef CONFIG_ZONE_DMA32
96 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
97 #endif
98 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
99
100 free_area_init(max_zone_pfns);
101 }
102
mem_init(void)103 void __init mem_init(void)
104 {
105 max_mapnr = max_low_pfn;
106 high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
107
108 memblock_free_all();
109 setup_zero_pages(); /* Setup zeroed pages. */
110 }
111 #endif /* !CONFIG_NUMA */
112
free_initmem(void)113 void __ref free_initmem(void)
114 {
115 free_initmem_default(POISON_FREE_INITMEM);
116 }
117
118 #ifdef CONFIG_MEMORY_HOTPLUG
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)119 int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
120 {
121 unsigned long start_pfn = start >> PAGE_SHIFT;
122 unsigned long nr_pages = size >> PAGE_SHIFT;
123 int ret;
124
125 ret = __add_pages(nid, start_pfn, nr_pages, params);
126
127 if (ret)
128 pr_warn("%s: Problem encountered in __add_pages() as ret=%d\n",
129 __func__, ret);
130
131 return ret;
132 }
133
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap)134 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
135 {
136 unsigned long start_pfn = start >> PAGE_SHIFT;
137 unsigned long nr_pages = size >> PAGE_SHIFT;
138 struct page *page = pfn_to_page(start_pfn);
139
140 /* With altmap the first mapped page is offset from @start */
141 if (altmap)
142 page += vmem_altmap_offset(altmap);
143 __remove_pages(start_pfn, nr_pages, altmap);
144 }
145
146 #ifdef CONFIG_NUMA
memory_add_physaddr_to_nid(u64 start)147 int memory_add_physaddr_to_nid(u64 start)
148 {
149 return pa_to_nid(start);
150 }
151 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
152 #endif
153 #endif
154
155 #ifdef CONFIG_SPARSEMEM_VMEMMAP
vmemmap_set_pmd(pmd_t * pmd,void * p,int node,unsigned long addr,unsigned long next)156 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
157 unsigned long addr, unsigned long next)
158 {
159 pmd_t entry;
160
161 entry = pfn_pmd(virt_to_pfn(p), PAGE_KERNEL);
162 pmd_val(entry) |= _PAGE_HUGE | _PAGE_HGLOBAL;
163 set_pmd_at(&init_mm, addr, pmd, entry);
164 }
165
vmemmap_check_pmd(pmd_t * pmd,int node,unsigned long addr,unsigned long next)166 int __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
167 unsigned long addr, unsigned long next)
168 {
169 int huge = pmd_val(*pmd) & _PAGE_HUGE;
170
171 if (huge)
172 vmemmap_verify((pte_t *)pmd, node, addr, next);
173
174 return huge;
175 }
176
vmemmap_populate(unsigned long start,unsigned long end,int node,struct vmem_altmap * altmap)177 int __meminit vmemmap_populate(unsigned long start, unsigned long end,
178 int node, struct vmem_altmap *altmap)
179 {
180 #if CONFIG_PGTABLE_LEVELS == 2
181 return vmemmap_populate_basepages(start, end, node, NULL);
182 #else
183 return vmemmap_populate_hugepages(start, end, node, NULL);
184 #endif
185 }
186
187 #ifdef CONFIG_MEMORY_HOTPLUG
vmemmap_free(unsigned long start,unsigned long end,struct vmem_altmap * altmap)188 void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
189 {
190 }
191 #endif
192 #endif
193
fixmap_pte(unsigned long addr)194 static pte_t *fixmap_pte(unsigned long addr)
195 {
196 pgd_t *pgd;
197 p4d_t *p4d;
198 pud_t *pud;
199 pmd_t *pmd;
200
201 pgd = pgd_offset_k(addr);
202 p4d = p4d_offset(pgd, addr);
203
204 if (pgd_none(*pgd)) {
205 pud_t *new __maybe_unused;
206
207 new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
208 pgd_populate(&init_mm, pgd, new);
209 #ifndef __PAGETABLE_PUD_FOLDED
210 pud_init(new);
211 #endif
212 }
213
214 pud = pud_offset(p4d, addr);
215 if (pud_none(*pud)) {
216 pmd_t *new __maybe_unused;
217
218 new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
219 pud_populate(&init_mm, pud, new);
220 #ifndef __PAGETABLE_PMD_FOLDED
221 pmd_init(new);
222 #endif
223 }
224
225 pmd = pmd_offset(pud, addr);
226 if (pmd_none(*pmd)) {
227 pte_t *new __maybe_unused;
228
229 new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
230 pmd_populate_kernel(&init_mm, pmd, new);
231 }
232
233 return pte_offset_kernel(pmd, addr);
234 }
235
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t flags)236 void __init __set_fixmap(enum fixed_addresses idx,
237 phys_addr_t phys, pgprot_t flags)
238 {
239 unsigned long addr = __fix_to_virt(idx);
240 pte_t *ptep;
241
242 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
243
244 ptep = fixmap_pte(addr);
245 if (!pte_none(*ptep)) {
246 pte_ERROR(*ptep);
247 return;
248 }
249
250 if (pgprot_val(flags))
251 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
252 else {
253 pte_clear(&init_mm, addr, ptep);
254 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
255 }
256 }
257
258 /*
259 * Align swapper_pg_dir in to 64K, allows its address to be loaded
260 * with a single LUI instruction in the TLB handlers. If we used
261 * __aligned(64K), its size would get rounded up to the alignment
262 * size, and waste space. So we place it in its own section and align
263 * it in the linker script.
264 */
265 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
266
267 pgd_t invalid_pg_dir[_PTRS_PER_PGD] __page_aligned_bss;
268 #ifndef __PAGETABLE_PUD_FOLDED
269 pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
270 #endif
271 #ifndef __PAGETABLE_PMD_FOLDED
272 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
273 EXPORT_SYMBOL_GPL(invalid_pmd_table);
274 #endif
275 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
276 EXPORT_SYMBOL(invalid_pte_table);
277