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/initrd.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 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 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 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 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 } 102 103 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 */ 112 113 void __ref free_initmem(void) 114 { 115 free_initmem_default(POISON_FREE_INITMEM); 116 } 117 118 #ifdef CONFIG_MEMORY_HOTPLUG 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 } 133 134 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 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 static pte_t *fixmap_pte(unsigned long addr) 156 { 157 pgd_t *pgd; 158 p4d_t *p4d; 159 pud_t *pud; 160 pmd_t *pmd; 161 162 pgd = pgd_offset_k(addr); 163 p4d = p4d_offset(pgd, addr); 164 165 if (pgd_none(*pgd)) { 166 pud_t *new __maybe_unused; 167 168 new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); 169 pgd_populate(&init_mm, pgd, new); 170 #ifndef __PAGETABLE_PUD_FOLDED 171 pud_init((unsigned long)new, (unsigned long)invalid_pmd_table); 172 #endif 173 } 174 175 pud = pud_offset(p4d, addr); 176 if (pud_none(*pud)) { 177 pmd_t *new __maybe_unused; 178 179 new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); 180 pud_populate(&init_mm, pud, new); 181 #ifndef __PAGETABLE_PMD_FOLDED 182 pmd_init((unsigned long)new, (unsigned long)invalid_pte_table); 183 #endif 184 } 185 186 pmd = pmd_offset(pud, addr); 187 if (pmd_none(*pmd)) { 188 pte_t *new __maybe_unused; 189 190 new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); 191 pmd_populate_kernel(&init_mm, pmd, new); 192 } 193 194 return pte_offset_kernel(pmd, addr); 195 } 196 197 void __init __set_fixmap(enum fixed_addresses idx, 198 phys_addr_t phys, pgprot_t flags) 199 { 200 unsigned long addr = __fix_to_virt(idx); 201 pte_t *ptep; 202 203 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 204 205 ptep = fixmap_pte(addr); 206 if (!pte_none(*ptep)) { 207 pte_ERROR(*ptep); 208 return; 209 } 210 211 if (pgprot_val(flags)) 212 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags)); 213 else { 214 pte_clear(&init_mm, addr, ptep); 215 flush_tlb_kernel_range(addr, addr + PAGE_SIZE); 216 } 217 } 218 219 /* 220 * Align swapper_pg_dir in to 64K, allows its address to be loaded 221 * with a single LUI instruction in the TLB handlers. If we used 222 * __aligned(64K), its size would get rounded up to the alignment 223 * size, and waste space. So we place it in its own section and align 224 * it in the linker script. 225 */ 226 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(".bss..swapper_pg_dir"); 227 228 pgd_t invalid_pg_dir[_PTRS_PER_PGD] __page_aligned_bss; 229 #ifndef __PAGETABLE_PUD_FOLDED 230 pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss; 231 #endif 232 #ifndef __PAGETABLE_PMD_FOLDED 233 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss; 234 EXPORT_SYMBOL_GPL(invalid_pmd_table); 235 #endif 236 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss; 237 EXPORT_SYMBOL(invalid_pte_table); 238