x86/speculation/mds: Fix documentation typo
[linux/fpc-iii.git] / arch / nios2 / kernel / setup.c
blob926a02b17b31f36df84655176aa5757f3b13a4a9
1 /*
2 * Nios2-specific parts of system setup
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>
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.
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>
24 #include <asm/mmu_context.h>
25 #include <asm/sections.h>
26 #include <asm/setup.h>
27 #include <asm/cpuinfo.h>
29 unsigned long memory_start;
30 EXPORT_SYMBOL(memory_start);
32 unsigned long memory_end;
33 EXPORT_SYMBOL(memory_end);
35 unsigned long memory_size;
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};
41 #ifdef CONFIG_VT
42 struct screen_info screen_info;
43 #endif
45 /* Copy a short hook instruction sequence to the exception address */
46 static inline void copy_exception_handler(unsigned int addr)
48 unsigned int start = (unsigned int) exception_handler_hook;
49 volatile unsigned int tmp = 0;
51 if (start == addr) {
52 /* The CPU exception address already points to the handler. */
53 return;
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"
78 /* Copy the fast TLB miss handler */
79 static inline void copy_fast_tlb_miss_handler(unsigned int addr)
81 unsigned int start = (unsigned int) fast_handler;
82 unsigned int end = (unsigned int) fast_handler_end;
83 volatile unsigned int tmp = 0;
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"
102 * save args passed from u-boot, called from head.S
104 * @r4: NIOS magic
105 * @r5: initrd start
106 * @r6: initrd end or fdt
107 * @r7: kernel command line
109 asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
110 unsigned r7)
112 unsigned dtb_passed = 0;
113 char cmdline_passed[COMMAND_LINE_SIZE] __maybe_unused = { 0, };
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;
122 #endif /* CONFIG_BLK_DEV_INITRD */
123 dtb_passed = r6;
125 if (r7)
126 strncpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
128 #endif
130 early_init_devtree((void *)dtb_passed);
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
141 parse_early_param();
144 void __init setup_arch(char **cmdline_p)
146 int bootmap_size;
148 console_verbose();
150 memory_start = PAGE_ALIGN((unsigned long)__pa(_end));
151 memory_end = (unsigned long) CONFIG_NIOS2_MEM_BASE + memory_size;
153 init_mm.start_code = (unsigned long) _stext;
154 init_mm.end_code = (unsigned long) _etext;
155 init_mm.end_data = (unsigned long) _edata;
156 init_mm.brk = (unsigned long) _end;
157 init_task.thread.kregs = &fake_regs;
159 /* Keep a copy of command line */
160 *cmdline_p = boot_command_line;
162 min_low_pfn = PFN_UP(memory_start);
163 max_low_pfn = PFN_DOWN(memory_end);
164 max_mapnr = max_low_pfn;
167 * give all the memory to the bootmap allocator, tell it to put the
168 * boot mem_map at the start of memory
170 pr_debug("init_bootmem_node(?,%#lx, %#x, %#lx)\n",
171 min_low_pfn, PFN_DOWN(PHYS_OFFSET), max_low_pfn);
172 bootmap_size = init_bootmem_node(NODE_DATA(0),
173 min_low_pfn, PFN_DOWN(PHYS_OFFSET),
174 max_low_pfn);
177 * free the usable memory, we have to make sure we do not free
178 * the bootmem bitmap so we then reserve it after freeing it :-)
180 pr_debug("free_bootmem(%#lx, %#lx)\n",
181 memory_start, memory_end - memory_start);
182 free_bootmem(memory_start, memory_end - memory_start);
185 * Reserve the bootmem bitmap itself as well. We do this in two
186 * steps (first step was init_bootmem()) because this catches
187 * the (very unlikely) case of us accidentally initializing the
188 * bootmem allocator with an invalid RAM area.
190 * Arguments are start, size
192 pr_debug("reserve_bootmem(%#lx, %#x)\n", memory_start, bootmap_size);
193 reserve_bootmem(memory_start, bootmap_size, BOOTMEM_DEFAULT);
195 #ifdef CONFIG_BLK_DEV_INITRD
196 if (initrd_start) {
197 reserve_bootmem(virt_to_phys((void *)initrd_start),
198 initrd_end - initrd_start, BOOTMEM_DEFAULT);
200 #endif /* CONFIG_BLK_DEV_INITRD */
202 early_init_fdt_reserve_self();
203 early_init_fdt_scan_reserved_mem();
205 unflatten_and_copy_device_tree();
207 setup_cpuinfo();
209 copy_exception_handler(cpuinfo.exception_addr);
211 mmu_init();
213 copy_fast_tlb_miss_handler(cpuinfo.fast_tlb_miss_exc_addr);
216 * Initialize MMU context handling here because data from cpuinfo is
217 * needed for this.
219 mmu_context_init();
222 * get kmalloc into gear
224 paging_init();
226 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
227 conswitchp = &dummy_con;
228 #endif