xref: /linux/arch/loongarch/mm/init.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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 #include <linux/execmem.h>
28 
29 #include <asm/asm-offsets.h>
30 #include <asm/bootinfo.h>
31 #include <asm/cpu.h>
32 #include <asm/dma.h>
33 #include <asm/mmu_context.h>
34 #include <asm/sections.h>
35 #include <asm/pgtable.h>
36 #include <asm/pgalloc.h>
37 #include <asm/tlb.h>
38 
39 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
40 EXPORT_SYMBOL(empty_zero_page);
41 
42 void copy_user_highpage(struct page *to, struct page *from,
43 	unsigned long vaddr, struct vm_area_struct *vma)
44 {
45 	void *vfrom, *vto;
46 
47 	vfrom = kmap_local_page(from);
48 	vto = kmap_local_page(to);
49 	copy_page(vto, vfrom);
50 	kunmap_local(vfrom);
51 	kunmap_local(vto);
52 	/* Make sure this page is cleared on other CPU's too before using it */
53 	smp_wmb();
54 }
55 
56 int __ref page_is_ram(unsigned long pfn)
57 {
58 	unsigned long addr = PFN_PHYS(pfn);
59 
60 	return memblock_is_memory(addr) && !memblock_is_reserved(addr);
61 }
62 
63 #ifndef CONFIG_NUMA
64 void __init paging_init(void)
65 {
66 	unsigned long max_zone_pfns[MAX_NR_ZONES];
67 
68 #ifdef CONFIG_ZONE_DMA
69 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
70 #endif
71 #ifdef CONFIG_ZONE_DMA32
72 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
73 #endif
74 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
75 
76 	free_area_init(max_zone_pfns);
77 }
78 
79 void __init mem_init(void)
80 {
81 	max_mapnr = max_low_pfn;
82 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
83 
84 	memblock_free_all();
85 }
86 #endif /* !CONFIG_NUMA */
87 
88 void __ref free_initmem(void)
89 {
90 	free_initmem_default(POISON_FREE_INITMEM);
91 }
92 
93 #ifdef CONFIG_MEMORY_HOTPLUG
94 int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
95 {
96 	unsigned long start_pfn = start >> PAGE_SHIFT;
97 	unsigned long nr_pages = size >> PAGE_SHIFT;
98 	int ret;
99 
100 	ret = __add_pages(nid, start_pfn, nr_pages, params);
101 
102 	if (ret)
103 		pr_warn("%s: Problem encountered in __add_pages() as ret=%d\n",
104 				__func__,  ret);
105 
106 	return ret;
107 }
108 
109 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
110 {
111 	unsigned long start_pfn = start >> PAGE_SHIFT;
112 	unsigned long nr_pages = size >> PAGE_SHIFT;
113 	struct page *page = pfn_to_page(start_pfn);
114 
115 	/* With altmap the first mapped page is offset from @start */
116 	if (altmap)
117 		page += vmem_altmap_offset(altmap);
118 	__remove_pages(start_pfn, nr_pages, altmap);
119 }
120 
121 #ifdef CONFIG_NUMA
122 int memory_add_physaddr_to_nid(u64 start)
123 {
124 	return pa_to_nid(start);
125 }
126 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
127 #endif
128 #endif
129 
130 #ifdef CONFIG_SPARSEMEM_VMEMMAP
131 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
132 			       unsigned long addr, unsigned long next)
133 {
134 	pmd_t entry;
135 
136 	entry = pfn_pmd(virt_to_pfn(p), PAGE_KERNEL);
137 	pmd_val(entry) |= _PAGE_HUGE | _PAGE_HGLOBAL;
138 	set_pmd_at(&init_mm, addr, pmd, entry);
139 }
140 
141 int __meminit vmemmap_check_pmd(pmd_t *pmd, int node,
142 				unsigned long addr, unsigned long next)
143 {
144 	int huge = pmd_val(pmdp_get(pmd)) & _PAGE_HUGE;
145 
146 	if (huge)
147 		vmemmap_verify((pte_t *)pmd, node, addr, next);
148 
149 	return huge;
150 }
151 
152 int __meminit vmemmap_populate(unsigned long start, unsigned long end,
153 			       int node, struct vmem_altmap *altmap)
154 {
155 #if CONFIG_PGTABLE_LEVELS == 2
156 	return vmemmap_populate_basepages(start, end, node, NULL);
157 #else
158 	return vmemmap_populate_hugepages(start, end, node, NULL);
159 #endif
160 }
161 
162 #ifdef CONFIG_MEMORY_HOTPLUG
163 void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
164 {
165 }
166 #endif
167 #endif
168 
169 pte_t * __init populate_kernel_pte(unsigned long addr)
170 {
171 	pgd_t *pgd = pgd_offset_k(addr);
172 	p4d_t *p4d = p4d_offset(pgd, addr);
173 	pud_t *pud;
174 	pmd_t *pmd;
175 
176 	if (p4d_none(p4dp_get(p4d))) {
177 		pud = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
178 		if (!pud)
179 			panic("%s: Failed to allocate memory\n", __func__);
180 		p4d_populate(&init_mm, p4d, pud);
181 #ifndef __PAGETABLE_PUD_FOLDED
182 		pud_init(pud);
183 #endif
184 	}
185 
186 	pud = pud_offset(p4d, addr);
187 	if (pud_none(pudp_get(pud))) {
188 		pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
189 		if (!pmd)
190 			panic("%s: Failed to allocate memory\n", __func__);
191 		pud_populate(&init_mm, pud, pmd);
192 #ifndef __PAGETABLE_PMD_FOLDED
193 		pmd_init(pmd);
194 #endif
195 	}
196 
197 	pmd = pmd_offset(pud, addr);
198 	if (!pmd_present(pmdp_get(pmd))) {
199 		pte_t *pte;
200 
201 		pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
202 		if (!pte)
203 			panic("%s: Failed to allocate memory\n", __func__);
204 		pmd_populate_kernel(&init_mm, pmd, pte);
205 	}
206 
207 	return pte_offset_kernel(pmd, addr);
208 }
209 
210 void __init __set_fixmap(enum fixed_addresses idx,
211 			       phys_addr_t phys, pgprot_t flags)
212 {
213 	unsigned long addr = __fix_to_virt(idx);
214 	pte_t *ptep;
215 
216 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
217 
218 	ptep = populate_kernel_pte(addr);
219 	if (!pte_none(ptep_get(ptep))) {
220 		pte_ERROR(*ptep);
221 		return;
222 	}
223 
224 	if (pgprot_val(flags))
225 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
226 	else {
227 		pte_clear(&init_mm, addr, ptep);
228 		flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
229 	}
230 }
231 
232 /*
233  * Align swapper_pg_dir in to 64K, allows its address to be loaded
234  * with a single LUI instruction in the TLB handlers.  If we used
235  * __aligned(64K), its size would get rounded up to the alignment
236  * size, and waste space.  So we place it in its own section and align
237  * it in the linker script.
238  */
239 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
240 
241 pgd_t invalid_pg_dir[_PTRS_PER_PGD] __page_aligned_bss;
242 #ifndef __PAGETABLE_PUD_FOLDED
243 pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
244 EXPORT_SYMBOL(invalid_pud_table);
245 #endif
246 #ifndef __PAGETABLE_PMD_FOLDED
247 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
248 EXPORT_SYMBOL(invalid_pmd_table);
249 #endif
250 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
251 EXPORT_SYMBOL(invalid_pte_table);
252 
253 #ifdef CONFIG_EXECMEM
254 static struct execmem_info execmem_info __ro_after_init;
255 
256 struct execmem_info __init *execmem_arch_setup(void)
257 {
258 	execmem_info = (struct execmem_info){
259 		.ranges = {
260 			[EXECMEM_DEFAULT] = {
261 				.start	= MODULES_VADDR,
262 				.end	= MODULES_END,
263 				.pgprot	= PAGE_KERNEL,
264 				.alignment = 1,
265 			},
266 		},
267 	};
268 
269 	return &execmem_info;
270 }
271 #endif /* CONFIG_EXECMEM */
272