1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * OpenRISC idle.c 4 * 5 * Linux architectural port borrowing liberally from similar works of 6 * others. All original copyrights apply as per the original source 7 * declaration. 8 * 9 * Modifications for the OpenRISC architecture: 10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 12 */ 13 14 #include <linux/signal.h> 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/errno.h> 18 #include <linux/string.h> 19 #include <linux/types.h> 20 #include <linux/ptrace.h> 21 #include <linux/mman.h> 22 #include <linux/mm.h> 23 #include <linux/swap.h> 24 #include <linux/smp.h> 25 #include <linux/memblock.h> 26 #include <linux/init.h> 27 #include <linux/delay.h> 28 #include <linux/pagemap.h> 29 30 #include <asm/pgalloc.h> 31 #include <asm/dma.h> 32 #include <asm/io.h> 33 #include <asm/tlb.h> 34 #include <asm/mmu_context.h> 35 #include <asm/fixmap.h> 36 #include <asm/tlbflush.h> 37 #include <asm/sections.h> 38 39 int mem_init_done; 40 41 static void __init zone_sizes_init(void) 42 { 43 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 }; 44 45 /* 46 * We use only ZONE_NORMAL 47 */ 48 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 49 50 free_area_init(max_zone_pfn); 51 } 52 53 extern const char _s_kernel_ro[], _e_kernel_ro[]; 54 55 /* 56 * Map all physical memory into kernel's address space. 57 * 58 * This is explicitly coded for two-level page tables, so if you need 59 * something else then this needs to change. 60 */ 61 static void __init map_ram(void) 62 { 63 phys_addr_t start, end; 64 unsigned long v, p, e; 65 pgprot_t prot; 66 pgd_t *pge; 67 p4d_t *p4e; 68 pud_t *pue; 69 pmd_t *pme; 70 pte_t *pte; 71 u64 i; 72 /* These mark extents of read-only kernel pages... 73 * ...from vmlinux.lds.S 74 */ 75 76 v = PAGE_OFFSET; 77 78 for_each_mem_range(i, &start, &end) { 79 p = (u32) start & PAGE_MASK; 80 e = (u32) end; 81 82 v = (u32) __va(p); 83 pge = pgd_offset_k(v); 84 85 while (p < e) { 86 int j; 87 p4e = p4d_offset(pge, v); 88 pue = pud_offset(p4e, v); 89 pme = pmd_offset(pue, v); 90 91 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) { 92 panic("%s: OR1K kernel hardcoded for " 93 "two-level page tables", 94 __func__); 95 } 96 97 /* Alloc one page for holding PTE's... */ 98 pte = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE); 99 if (!pte) 100 panic("%s: Failed to allocate page for PTEs\n", 101 __func__); 102 set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte))); 103 104 /* Fill the newly allocated page with PTE'S */ 105 for (j = 0; p < e && j < PTRS_PER_PTE; 106 v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) { 107 if (v >= (u32) _e_kernel_ro || 108 v < (u32) _s_kernel_ro) 109 prot = PAGE_KERNEL; 110 else 111 prot = PAGE_KERNEL_RO; 112 113 set_pte(pte, mk_pte_phys(p, prot)); 114 } 115 116 pge++; 117 } 118 119 printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__, 120 start, end); 121 } 122 } 123 124 void __init paging_init(void) 125 { 126 int i; 127 128 printk(KERN_INFO "Setting up paging and PTEs.\n"); 129 130 /* clear out the init_mm.pgd that will contain the kernel's mappings */ 131 132 for (i = 0; i < PTRS_PER_PGD; i++) 133 swapper_pg_dir[i] = __pgd(0); 134 135 /* make sure the current pgd table points to something sane 136 * (even if it is most probably not used until the next 137 * switch_mm) 138 */ 139 current_pgd[smp_processor_id()] = init_mm.pgd; 140 141 map_ram(); 142 143 zone_sizes_init(); 144 145 /* self modifying code ;) */ 146 /* Since the old TLB miss handler has been running up until now, 147 * the kernel pages are still all RW, so we can still modify the 148 * text directly... after this change and a TLB flush, the kernel 149 * pages will become RO. 150 */ 151 { 152 extern unsigned long dtlb_miss_handler; 153 extern unsigned long itlb_miss_handler; 154 155 unsigned long *dtlb_vector = __va(0x900); 156 unsigned long *itlb_vector = __va(0xa00); 157 158 printk(KERN_INFO "itlb_miss_handler %p\n", &itlb_miss_handler); 159 *itlb_vector = ((unsigned long)&itlb_miss_handler - 160 (unsigned long)itlb_vector) >> 2; 161 162 /* Soft ordering constraint to ensure that dtlb_vector is 163 * the last thing updated 164 */ 165 barrier(); 166 167 printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler); 168 *dtlb_vector = ((unsigned long)&dtlb_miss_handler - 169 (unsigned long)dtlb_vector) >> 2; 170 171 } 172 173 /* Soft ordering constraint to ensure that cache invalidation and 174 * TLB flush really happen _after_ code has been modified. 175 */ 176 barrier(); 177 178 /* Invalidate instruction caches after code modification */ 179 mtspr(SPR_ICBIR, 0x900); 180 mtspr(SPR_ICBIR, 0xa00); 181 182 /* New TLB miss handlers and kernel page tables are in now place. 183 * Make sure that page flags get updated for all pages in TLB by 184 * flushing the TLB and forcing all TLB entries to be recreated 185 * from their page table flags. 186 */ 187 flush_tlb_all(); 188 } 189 190 /* References to section boundaries */ 191 192 void __init mem_init(void) 193 { 194 BUG_ON(!mem_map); 195 196 max_mapnr = max_low_pfn; 197 high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); 198 199 /* clear the zero-page */ 200 memset((void *)empty_zero_page, 0, PAGE_SIZE); 201 202 /* this will put all low memory onto the freelists */ 203 memblock_free_all(); 204 205 printk("mem_init_done ...........................................\n"); 206 mem_init_done = 1; 207 return; 208 } 209 210 static const pgprot_t protection_map[16] = { 211 [VM_NONE] = PAGE_NONE, 212 [VM_READ] = PAGE_READONLY_X, 213 [VM_WRITE] = PAGE_COPY, 214 [VM_WRITE | VM_READ] = PAGE_COPY_X, 215 [VM_EXEC] = PAGE_READONLY, 216 [VM_EXEC | VM_READ] = PAGE_READONLY_X, 217 [VM_EXEC | VM_WRITE] = PAGE_COPY, 218 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_X, 219 [VM_SHARED] = PAGE_NONE, 220 [VM_SHARED | VM_READ] = PAGE_READONLY_X, 221 [VM_SHARED | VM_WRITE] = PAGE_SHARED, 222 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_X, 223 [VM_SHARED | VM_EXEC] = PAGE_READONLY, 224 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_X, 225 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED, 226 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_X 227 }; 228 DECLARE_VM_GET_PAGE_PROT 229