source: src/linux/universal/linux-4.4/arch/nios2/kernel/setup.c @ 31859

Last change on this file since 31859 was 31859, checked in by brainslayer, 11 days ago

kernel update

File size: 5.4 KB
Line 
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/console.h>
18#include <linux/bootmem.h>
19#include <linux/initrd.h>
20#include <linux/of_fdt.h>
21
22#include <asm/mmu_context.h>
23#include <asm/sections.h>
24#include <asm/setup.h>
25#include <asm/cpuinfo.h>
26
27unsigned long memory_start;
28EXPORT_SYMBOL(memory_start);
29
30unsigned long memory_end;
31EXPORT_SYMBOL(memory_end);
32
33unsigned long memory_size;
34
35static struct pt_regs fake_regs = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
36                                        0, 0, 0, 0, 0, 0,
37                                        0};
38
39/* Copy a short hook instruction sequence to the exception address */
40static inline void copy_exception_handler(unsigned int addr)
41{
42        unsigned int start = (unsigned int) exception_handler_hook;
43        volatile unsigned int tmp = 0;
44
45        if (start == addr) {
46                /* The CPU exception address already points to the handler. */
47                return;
48        }
49
50        __asm__ __volatile__ (
51                "ldw    %2,0(%0)\n"
52                "stw    %2,0(%1)\n"
53                "ldw    %2,4(%0)\n"
54                "stw    %2,4(%1)\n"
55                "ldw    %2,8(%0)\n"
56                "stw    %2,8(%1)\n"
57                "flushd 0(%1)\n"
58                "flushd 4(%1)\n"
59                "flushd 8(%1)\n"
60                "flushi %1\n"
61                "addi   %1,%1,4\n"
62                "flushi %1\n"
63                "addi   %1,%1,4\n"
64                "flushi %1\n"
65                "flushp\n"
66                : /* no output registers */
67                : "r" (start), "r" (addr), "r" (tmp)
68                : "memory"
69        );
70}
71
72/* Copy the fast TLB miss handler */
73static inline void copy_fast_tlb_miss_handler(unsigned int addr)
74{
75        unsigned int start = (unsigned int) fast_handler;
76        unsigned int end = (unsigned int) fast_handler_end;
77        volatile unsigned int tmp = 0;
78
79        __asm__ __volatile__ (
80                "1:\n"
81                "       ldw     %3,0(%0)\n"
82                "       stw     %3,0(%1)\n"
83                "       flushd  0(%1)\n"
84                "       flushi  %1\n"
85                "       flushp\n"
86                "       addi    %0,%0,4\n"
87                "       addi    %1,%1,4\n"
88                "       bne     %0,%2,1b\n"
89                : /* no output registers */
90                : "r" (start), "r" (addr), "r" (end), "r" (tmp)
91                : "memory"
92        );
93}
94
95/*
96 * save args passed from u-boot, called from head.S
97 *
98 * @r4: NIOS magic
99 * @r5: initrd start
100 * @r6: initrd end or fdt
101 * @r7: kernel command line
102 */
103asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,
104                                       unsigned r7)
105{
106        unsigned dtb_passed = 0;
107        char cmdline_passed[COMMAND_LINE_SIZE] __maybe_unused = { 0, };
108
109#if defined(CONFIG_NIOS2_PASS_CMDLINE)
110        if (r4 == 0x534f494e) { /* r4 is magic NIOS */
111#if defined(CONFIG_BLK_DEV_INITRD)
112                if (r5) { /* initramfs */
113                        initrd_start = r5;
114                        initrd_end = r6;
115                }
116#endif /* CONFIG_BLK_DEV_INITRD */
117                dtb_passed = r6;
118
119                if (r7)
120                        strncpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);
121        }
122#endif
123
124        early_init_devtree((void *)dtb_passed);
125
126#ifndef CONFIG_CMDLINE_FORCE
127        if (cmdline_passed[0])
128                strncpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
129#ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB
130        else
131                strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
132#endif
133#endif
134}
135
136void __init setup_arch(char **cmdline_p)
137{
138        int bootmap_size;
139
140        console_verbose();
141
142#ifdef CONFIG_EARLY_PRINTK
143        setup_early_printk();
144#endif
145
146        memory_start = PAGE_ALIGN((unsigned long)__pa(_end));
147        memory_end = (unsigned long) CONFIG_NIOS2_MEM_BASE + memory_size;
148
149        init_mm.start_code = (unsigned long) _stext;
150        init_mm.end_code = (unsigned long) _etext;
151        init_mm.end_data = (unsigned long) _edata;
152        init_mm.brk = (unsigned long) _end;
153        init_task.thread.kregs = &fake_regs;
154
155        /* Keep a copy of command line */
156        *cmdline_p = boot_command_line;
157
158        min_low_pfn = PFN_UP(memory_start);
159        max_low_pfn = PFN_DOWN(memory_end);
160        max_mapnr = max_low_pfn;
161
162        /*
163         * give all the memory to the bootmap allocator,  tell it to put the
164         * boot mem_map at the start of memory
165         */
166        pr_debug("init_bootmem_node(?,%#lx, %#x, %#lx)\n",
167                min_low_pfn, PFN_DOWN(PHYS_OFFSET), max_low_pfn);
168        bootmap_size = init_bootmem_node(NODE_DATA(0),
169                                        min_low_pfn, PFN_DOWN(PHYS_OFFSET),
170                                        max_low_pfn);
171
172        /*
173         * free the usable memory,  we have to make sure we do not free
174         * the bootmem bitmap so we then reserve it after freeing it :-)
175         */
176        pr_debug("free_bootmem(%#lx, %#lx)\n",
177                memory_start, memory_end - memory_start);
178        free_bootmem(memory_start, memory_end - memory_start);
179
180        /*
181         * Reserve the bootmem bitmap itself as well. We do this in two
182         * steps (first step was init_bootmem()) because this catches
183         * the (very unlikely) case of us accidentally initializing the
184         * bootmem allocator with an invalid RAM area.
185         *
186         * Arguments are start, size
187         */
188        pr_debug("reserve_bootmem(%#lx, %#x)\n", memory_start, bootmap_size);
189        reserve_bootmem(memory_start, bootmap_size, BOOTMEM_DEFAULT);
190
191#ifdef CONFIG_BLK_DEV_INITRD
192        if (initrd_start) {
193                reserve_bootmem(virt_to_phys((void *)initrd_start),
194                                initrd_end - initrd_start, BOOTMEM_DEFAULT);
195        }
196#endif /* CONFIG_BLK_DEV_INITRD */
197
198        early_init_fdt_reserve_self();
199        early_init_fdt_scan_reserved_mem();
200
201        unflatten_and_copy_device_tree();
202
203        setup_cpuinfo();
204
205        copy_exception_handler(cpuinfo.exception_addr);
206
207        mmu_init();
208
209        copy_fast_tlb_miss_handler(cpuinfo.fast_tlb_miss_exc_addr);
210
211        /*
212         * Initialize MMU context handling here because data from cpuinfo is
213         * needed for this.
214         */
215        mmu_context_init();
216
217        /*
218         * get kmalloc into gear
219         */
220        paging_init();
221
222#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
223        conswitchp = &dummy_con;
224#endif
225}
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