1 /* 2 * Nios2-specific parts of system setup 3 * 4 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch> 5 * Copyright (C) 2004 Microtronix Datacom Ltd. 6 * Copyright (C) 2001 Vic Phillips <vic@microtronix.com> 7 * 8 * This file is subject to the terms and conditions of the GNU General Public 9 * License. See the file "COPYING" in the main directory of this archive 10 * for more details. 11 */ 12 13 #include <linux/export.h> 14 #include <linux/kernel.h> 15 #include <linux/mm.h> 16 #include <linux/sched.h> 17 #include <linux/sched/task.h> 18 #include <linux/console.h> 19 #include <linux/bootmem.h> 20 #include <linux/initrd.h> 21 #include <linux/of_fdt.h> 22 #include <linux/screen_info.h> 23 24 #include <asm/mmu_context.h> 25 #include <asm/sections.h> 26 #include <asm/setup.h> 27 #include <asm/cpuinfo.h> 28 29 unsigned long memory_start; 30 EXPORT_SYMBOL(memory_start); 31 32 unsigned long memory_end; 33 EXPORT_SYMBOL(memory_end); 34 35 unsigned long memory_size; 36 37 static struct pt_regs fake_regs = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 38 0, 0, 0, 0, 0, 0, 39 0}; 40 41 #ifdef CONFIG_VT 42 struct screen_info screen_info; 43 #endif 44 45 /* Copy a short hook instruction sequence to the exception address */ 46 static inline void copy_exception_handler(unsigned int addr) 47 { 48 unsigned int start = (unsigned int) exception_handler_hook; 49 volatile unsigned int tmp = 0; 50 51 if (start == addr) { 52 /* The CPU exception address already points to the handler. */ 53 return; 54 } 55 56 __asm__ __volatile__ ( 57 "ldw %2,0(%0)\n" 58 "stw %2,0(%1)\n" 59 "ldw %2,4(%0)\n" 60 "stw %2,4(%1)\n" 61 "ldw %2,8(%0)\n" 62 "stw %2,8(%1)\n" 63 "flushd 0(%1)\n" 64 "flushd 4(%1)\n" 65 "flushd 8(%1)\n" 66 "flushi %1\n" 67 "addi %1,%1,4\n" 68 "flushi %1\n" 69 "addi %1,%1,4\n" 70 "flushi %1\n" 71 "flushp\n" 72 : /* no output registers */ 73 : "r" (start), "r" (addr), "r" (tmp) 74 : "memory" 75 ); 76 } 77 78 /* Copy the fast TLB miss handler */ 79 static inline void copy_fast_tlb_miss_handler(unsigned int addr) 80 { 81 unsigned int start = (unsigned int) fast_handler; 82 unsigned int end = (unsigned int) fast_handler_end; 83 volatile unsigned int tmp = 0; 84 85 __asm__ __volatile__ ( 86 "1:\n" 87 " ldw %3,0(%0)\n" 88 " stw %3,0(%1)\n" 89 " flushd 0(%1)\n" 90 " flushi %1\n" 91 " flushp\n" 92 " addi %0,%0,4\n" 93 " addi %1,%1,4\n" 94 " bne %0,%2,1b\n" 95 : /* no output registers */ 96 : "r" (start), "r" (addr), "r" (end), "r" (tmp) 97 : "memory" 98 ); 99 } 100 101 /* 102 * save args passed from u-boot, called from head.S 103 * 104 * @r4: NIOS magic 105 * @r5: initrd start 106 * @r6: initrd end or fdt 107 * @r7: kernel command line 108 */ 109 asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6, 110 unsigned r7) 111 { 112 unsigned dtb_passed = 0; 113 char cmdline_passed[COMMAND_LINE_SIZE] __maybe_unused = { 0, }; 114 115 #if defined(CONFIG_NIOS2_PASS_CMDLINE) 116 if (r4 == 0x534f494e) { /* r4 is magic NIOS */ 117 #if defined(CONFIG_BLK_DEV_INITRD) 118 if (r5) { /* initramfs */ 119 initrd_start = r5; 120 initrd_end = r6; 121 } 122 #endif /* CONFIG_BLK_DEV_INITRD */ 123 dtb_passed = r6; 124 125 if (r7) 126 strncpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE); 127 } 128 #endif 129 130 early_init_devtree((void *)dtb_passed); 131 132 #ifndef CONFIG_CMDLINE_FORCE 133 if (cmdline_passed[0]) 134 strncpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE); 135 #ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB 136 else 137 strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE); 138 #endif 139 #endif 140 } 141 142 void __init setup_arch(char **cmdline_p) 143 { 144 int bootmap_size; 145 146 console_verbose(); 147 148 #ifdef CONFIG_EARLY_PRINTK 149 setup_early_printk(); 150 #endif 151 152 memory_start = PAGE_ALIGN((unsigned long)__pa(_end)); 153 memory_end = (unsigned long) CONFIG_NIOS2_MEM_BASE + memory_size; 154 155 init_mm.start_code = (unsigned long) _stext; 156 init_mm.end_code = (unsigned long) _etext; 157 init_mm.end_data = (unsigned long) _edata; 158 init_mm.brk = (unsigned long) _end; 159 init_task.thread.kregs = &fake_regs; 160 161 /* Keep a copy of command line */ 162 *cmdline_p = boot_command_line; 163 164 min_low_pfn = PFN_UP(memory_start); 165 max_low_pfn = PFN_DOWN(memory_end); 166 max_mapnr = max_low_pfn; 167 168 /* 169 * give all the memory to the bootmap allocator, tell it to put the 170 * boot mem_map at the start of memory 171 */ 172 pr_debug("init_bootmem_node(?,%#lx, %#x, %#lx)\n", 173 min_low_pfn, PFN_DOWN(PHYS_OFFSET), max_low_pfn); 174 bootmap_size = init_bootmem_node(NODE_DATA(0), 175 min_low_pfn, PFN_DOWN(PHYS_OFFSET), 176 max_low_pfn); 177 178 /* 179 * free the usable memory, we have to make sure we do not free 180 * the bootmem bitmap so we then reserve it after freeing it :-) 181 */ 182 pr_debug("free_bootmem(%#lx, %#lx)\n", 183 memory_start, memory_end - memory_start); 184 free_bootmem(memory_start, memory_end - memory_start); 185 186 /* 187 * Reserve the bootmem bitmap itself as well. We do this in two 188 * steps (first step was init_bootmem()) because this catches 189 * the (very unlikely) case of us accidentally initializing the 190 * bootmem allocator with an invalid RAM area. 191 * 192 * Arguments are start, size 193 */ 194 pr_debug("reserve_bootmem(%#lx, %#x)\n", memory_start, bootmap_size); 195 reserve_bootmem(memory_start, bootmap_size, BOOTMEM_DEFAULT); 196 197 #ifdef CONFIG_BLK_DEV_INITRD 198 if (initrd_start) { 199 reserve_bootmem(virt_to_phys((void *)initrd_start), 200 initrd_end - initrd_start, BOOTMEM_DEFAULT); 201 } 202 #endif /* CONFIG_BLK_DEV_INITRD */ 203 204 early_init_fdt_reserve_self(); 205 early_init_fdt_scan_reserved_mem(); 206 207 unflatten_and_copy_device_tree(); 208 209 setup_cpuinfo(); 210 211 copy_exception_handler(cpuinfo.exception_addr); 212 213 mmu_init(); 214 215 copy_fast_tlb_miss_handler(cpuinfo.fast_tlb_miss_exc_addr); 216 217 /* 218 * Initialize MMU context handling here because data from cpuinfo is 219 * needed for this. 220 */ 221 mmu_context_init(); 222 223 /* 224 * get kmalloc into gear 225 */ 226 paging_init(); 227 228 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE) 229 conswitchp = &dummy_con; 230 #endif 231 } 232