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 32 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 33 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss; 34 EXPORT_SYMBOL(invalid_pte_table); 35 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] 36 __page_aligned_bss; 37 EXPORT_SYMBOL(empty_zero_page); 38 39 #ifdef CONFIG_BLK_DEV_INITRD 40 static void __init setup_initrd(void) 41 { 42 unsigned long size; 43 44 if (initrd_start >= initrd_end) { 45 pr_err("initrd not found or empty"); 46 goto disable; 47 } 48 49 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { 50 pr_err("initrd extends beyond end of memory"); 51 goto disable; 52 } 53 54 size = initrd_end - initrd_start; 55 56 if (memblock_is_region_reserved(__pa(initrd_start), size)) { 57 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region", 58 __pa(initrd_start), size); 59 goto disable; 60 } 61 62 memblock_reserve(__pa(initrd_start), size); 63 64 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 65 (void *)(initrd_start), size); 66 67 initrd_below_start_ok = 1; 68 69 return; 70 71 disable: 72 initrd_start = initrd_end = 0; 73 74 pr_err(" - disabling initrd\n"); 75 } 76 #endif 77 78 void __init mem_init(void) 79 { 80 #ifdef CONFIG_HIGHMEM 81 unsigned long tmp; 82 83 max_mapnr = highend_pfn; 84 #else 85 max_mapnr = max_low_pfn; 86 #endif 87 high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); 88 89 #ifdef CONFIG_BLK_DEV_INITRD 90 setup_initrd(); 91 #endif 92 93 memblock_free_all(); 94 95 #ifdef CONFIG_HIGHMEM 96 for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) { 97 struct page *page = pfn_to_page(tmp); 98 99 /* FIXME not sure about */ 100 if (!memblock_is_reserved(tmp << PAGE_SHIFT)) 101 free_highmem_page(page); 102 } 103 #endif 104 mem_init_print_info(NULL); 105 } 106 107 extern char __init_begin[], __init_end[]; 108 109 void free_initmem(void) 110 { 111 unsigned long addr; 112 113 addr = (unsigned long) &__init_begin; 114 115 while (addr < (unsigned long) &__init_end) { 116 ClearPageReserved(virt_to_page(addr)); 117 init_page_count(virt_to_page(addr)); 118 free_page(addr); 119 totalram_pages_inc(); 120 addr += PAGE_SIZE; 121 } 122 123 pr_info("Freeing unused kernel memory: %dk freed\n", 124 ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10); 125 } 126 127 void pgd_init(unsigned long *p) 128 { 129 int i; 130 131 for (i = 0; i < PTRS_PER_PGD; i++) 132 p[i] = __pa(invalid_pte_table); 133 } 134 135 void __init pre_mmu_init(void) 136 { 137 /* 138 * Setup page-table and enable TLB-hardrefill 139 */ 140 flush_tlb_all(); 141 pgd_init((unsigned long *)swapper_pg_dir); 142 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); 143 TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir); 144 145 /* Setup page mask to 4k */ 146 write_mmu_pagemask(0); 147 } 148 149 void __init fixrange_init(unsigned long start, unsigned long end, 150 pgd_t *pgd_base) 151 { 152 pgd_t *pgd; 153 pud_t *pud; 154 pmd_t *pmd; 155 pte_t *pte; 156 int i, j, k; 157 unsigned long vaddr; 158 159 vaddr = start; 160 i = pgd_index(vaddr); 161 j = pud_index(vaddr); 162 k = pmd_index(vaddr); 163 pgd = pgd_base + i; 164 165 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) { 166 pud = (pud_t *)pgd; 167 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) { 168 pmd = (pmd_t *)pud; 169 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) { 170 if (pmd_none(*pmd)) { 171 pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); 172 if (!pte) 173 panic("%s: Failed to allocate %lu bytes align=%lx\n", 174 __func__, PAGE_SIZE, 175 PAGE_SIZE); 176 177 set_pmd(pmd, __pmd(__pa(pte))); 178 BUG_ON(pte != pte_offset_kernel(pmd, 0)); 179 } 180 vaddr += PMD_SIZE; 181 } 182 k = 0; 183 } 184 j = 0; 185 } 186 } 187 188 void __init fixaddr_init(void) 189 { 190 unsigned long vaddr; 191 192 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 193 fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir); 194 } 195