1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/bug.h> 5 #include <linux/module.h> 6 #include <linux/init.h> 7 #include <linux/signal.h> 8 #include <linux/sched.h> 9 #include <linux/kernel.h> 10 #include <linux/errno.h> 11 #include <linux/string.h> 12 #include <linux/types.h> 13 #include <linux/pagemap.h> 14 #include <linux/ptrace.h> 15 #include <linux/mman.h> 16 #include <linux/mm.h> 17 #include <linux/highmem.h> 18 #include <linux/memblock.h> 19 #include <linux/swap.h> 20 #include <linux/proc_fs.h> 21 #include <linux/pfn.h> 22 #include <linux/initrd.h> 23 24 #include <asm/setup.h> 25 #include <asm/cachectl.h> 26 #include <asm/dma.h> 27 #include <asm/pgalloc.h> 28 #include <asm/mmu_context.h> 29 #include <asm/sections.h> 30 #include <asm/tlb.h> 31 #include <asm/cacheflush.h> 32 33 #define PTRS_KERN_TABLE \ 34 ((PTRS_PER_PGD - USER_PTRS_PER_PGD) * PTRS_PER_PTE) 35 36 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 37 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss; 38 pte_t kernel_pte_tables[PTRS_KERN_TABLE] __page_aligned_bss; 39 40 EXPORT_SYMBOL(invalid_pte_table); 41 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] 42 __page_aligned_bss; 43 EXPORT_SYMBOL(empty_zero_page); 44 45 #ifdef CONFIG_BLK_DEV_INITRD 46 static void __init setup_initrd(void) 47 { 48 unsigned long size; 49 50 if (initrd_start >= initrd_end) { 51 pr_err("initrd not found or empty"); 52 goto disable; 53 } 54 55 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { 56 pr_err("initrd extends beyond end of memory"); 57 goto disable; 58 } 59 60 size = initrd_end - initrd_start; 61 62 if (memblock_is_region_reserved(__pa(initrd_start), size)) { 63 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region", 64 __pa(initrd_start), size); 65 goto disable; 66 } 67 68 memblock_reserve(__pa(initrd_start), size); 69 70 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 71 (void *)(initrd_start), size); 72 73 initrd_below_start_ok = 1; 74 75 return; 76 77 disable: 78 initrd_start = initrd_end = 0; 79 80 pr_err(" - disabling initrd\n"); 81 } 82 #endif 83 84 void __init mem_init(void) 85 { 86 #ifdef CONFIG_HIGHMEM 87 unsigned long tmp; 88 89 max_mapnr = highend_pfn; 90 #else 91 max_mapnr = max_low_pfn; 92 #endif 93 high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); 94 95 #ifdef CONFIG_BLK_DEV_INITRD 96 setup_initrd(); 97 #endif 98 99 memblock_free_all(); 100 101 #ifdef CONFIG_HIGHMEM 102 for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) { 103 struct page *page = pfn_to_page(tmp); 104 105 /* FIXME not sure about */ 106 if (!memblock_is_reserved(tmp << PAGE_SHIFT)) 107 free_highmem_page(page); 108 } 109 #endif 110 mem_init_print_info(NULL); 111 } 112 113 extern char __init_begin[], __init_end[]; 114 115 void free_initmem(void) 116 { 117 unsigned long addr; 118 119 addr = (unsigned long) &__init_begin; 120 121 while (addr < (unsigned long) &__init_end) { 122 ClearPageReserved(virt_to_page(addr)); 123 init_page_count(virt_to_page(addr)); 124 free_page(addr); 125 totalram_pages_inc(); 126 addr += PAGE_SIZE; 127 } 128 129 pr_info("Freeing unused kernel memory: %dk freed\n", 130 ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10); 131 } 132 133 void pgd_init(unsigned long *p) 134 { 135 int i; 136 137 for (i = 0; i < PTRS_PER_PGD; i++) 138 p[i] = __pa(invalid_pte_table); 139 140 flush_tlb_all(); 141 local_icache_inv_all(NULL); 142 } 143 144 void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn) 145 { 146 int i; 147 148 for (i = 0; i < USER_PTRS_PER_PGD; i++) 149 swapper_pg_dir[i].pgd = __pa(invalid_pte_table); 150 151 for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++) 152 swapper_pg_dir[i].pgd = 153 __pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD))); 154 155 for (i = 0; i < PTRS_KERN_TABLE; i++) 156 set_pte(&kernel_pte_tables[i], __pte(_PAGE_GLOBAL)); 157 158 for (i = min_pfn; i < max_pfn; i++) 159 set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL)); 160 161 flush_tlb_all(); 162 local_icache_inv_all(NULL); 163 164 /* Setup page mask to 4k */ 165 write_mmu_pagemask(0); 166 167 setup_pgd(swapper_pg_dir, 0); 168 } 169 170 void __init fixrange_init(unsigned long start, unsigned long end, 171 pgd_t *pgd_base) 172 { 173 pgd_t *pgd; 174 pud_t *pud; 175 pmd_t *pmd; 176 pte_t *pte; 177 int i, j, k; 178 unsigned long vaddr; 179 180 vaddr = start; 181 i = pgd_index(vaddr); 182 j = pud_index(vaddr); 183 k = pmd_index(vaddr); 184 pgd = pgd_base + i; 185 186 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) { 187 pud = (pud_t *)pgd; 188 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) { 189 pmd = (pmd_t *)pud; 190 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) { 191 if (pmd_none(*pmd)) { 192 pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); 193 if (!pte) 194 panic("%s: Failed to allocate %lu bytes align=%lx\n", 195 __func__, PAGE_SIZE, 196 PAGE_SIZE); 197 198 set_pmd(pmd, __pmd(__pa(pte))); 199 BUG_ON(pte != pte_offset_kernel(pmd, 0)); 200 } 201 vaddr += PMD_SIZE; 202 } 203 k = 0; 204 } 205 j = 0; 206 } 207 } 208 209 void __init fixaddr_init(void) 210 { 211 unsigned long vaddr; 212 213 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 214 fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir); 215 } 216