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/pgtable.h> 28 #include <asm/pgalloc.h> 29 #include <asm/mmu_context.h> 30 #include <asm/sections.h> 31 #include <asm/tlb.h> 32 33 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 34 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss; 35 EXPORT_SYMBOL(invalid_pte_table); 36 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] 37 __page_aligned_bss; 38 EXPORT_SYMBOL(empty_zero_page); 39 40 #ifdef CONFIG_BLK_DEV_INITRD 41 static void __init setup_initrd(void) 42 { 43 unsigned long size; 44 45 if (initrd_start >= initrd_end) { 46 pr_err("initrd not found or empty"); 47 goto disable; 48 } 49 50 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { 51 pr_err("initrd extends beyond end of memory"); 52 goto disable; 53 } 54 55 size = initrd_end - initrd_start; 56 57 if (memblock_is_region_reserved(__pa(initrd_start), size)) { 58 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region", 59 __pa(initrd_start), size); 60 goto disable; 61 } 62 63 memblock_reserve(__pa(initrd_start), size); 64 65 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 66 (void *)(initrd_start), size); 67 68 initrd_below_start_ok = 1; 69 70 return; 71 72 disable: 73 initrd_start = initrd_end = 0; 74 75 pr_err(" - disabling initrd\n"); 76 } 77 #endif 78 79 void __init mem_init(void) 80 { 81 #ifdef CONFIG_HIGHMEM 82 unsigned long tmp; 83 84 max_mapnr = highend_pfn; 85 #else 86 max_mapnr = max_low_pfn; 87 #endif 88 high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); 89 90 #ifdef CONFIG_BLK_DEV_INITRD 91 setup_initrd(); 92 #endif 93 94 memblock_free_all(); 95 96 #ifdef CONFIG_HIGHMEM 97 for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) { 98 struct page *page = pfn_to_page(tmp); 99 100 /* FIXME not sure about */ 101 if (!memblock_is_reserved(tmp << PAGE_SHIFT)) 102 free_highmem_page(page); 103 } 104 #endif 105 mem_init_print_info(NULL); 106 } 107 108 extern char __init_begin[], __init_end[]; 109 110 void free_initmem(void) 111 { 112 unsigned long addr; 113 114 addr = (unsigned long) &__init_begin; 115 116 while (addr < (unsigned long) &__init_end) { 117 ClearPageReserved(virt_to_page(addr)); 118 init_page_count(virt_to_page(addr)); 119 free_page(addr); 120 totalram_pages_inc(); 121 addr += PAGE_SIZE; 122 } 123 124 pr_info("Freeing unused kernel memory: %dk freed\n", 125 ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10); 126 } 127 128 void pgd_init(unsigned long *p) 129 { 130 int i; 131 132 for (i = 0; i < PTRS_PER_PGD; i++) 133 p[i] = __pa(invalid_pte_table); 134 } 135 136 void __init pre_mmu_init(void) 137 { 138 /* 139 * Setup page-table and enable TLB-hardrefill 140 */ 141 flush_tlb_all(); 142 pgd_init((unsigned long *)swapper_pg_dir); 143 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); 144 TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir); 145 146 /* Setup page mask to 4k */ 147 write_mmu_pagemask(0); 148 } 149 150 void __init fixrange_init(unsigned long start, unsigned long end, 151 pgd_t *pgd_base) 152 { 153 pgd_t *pgd; 154 pud_t *pud; 155 pmd_t *pmd; 156 pte_t *pte; 157 int i, j, k; 158 unsigned long vaddr; 159 160 vaddr = start; 161 i = __pgd_offset(vaddr); 162 j = __pud_offset(vaddr); 163 k = __pmd_offset(vaddr); 164 pgd = pgd_base + i; 165 166 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) { 167 pud = (pud_t *)pgd; 168 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) { 169 pmd = (pmd_t *)pud; 170 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) { 171 if (pmd_none(*pmd)) { 172 pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); 173 if (!pte) 174 panic("%s: Failed to allocate %lu bytes align=%lx\n", 175 __func__, PAGE_SIZE, 176 PAGE_SIZE); 177 178 set_pmd(pmd, __pmd(__pa(pte))); 179 BUG_ON(pte != pte_offset_kernel(pmd, 0)); 180 } 181 vaddr += PMD_SIZE; 182 } 183 k = 0; 184 } 185 j = 0; 186 } 187 } 188 189 void __init fixaddr_init(void) 190 { 191 unsigned long vaddr; 192 193 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 194 fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir); 195 } 196