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/memblock.h> |
20 | #include <linux/initrd.h> |
21 | #include <linux/of_fdt.h> |
22 | |
23 | #include <asm/mmu_context.h> |
24 | #include <asm/sections.h> |
25 | #include <asm/setup.h> |
26 | #include <asm/cpuinfo.h> |
27 | |
28 | unsigned long memory_start; |
29 | EXPORT_SYMBOL(memory_start); |
30 | |
31 | unsigned long memory_end; |
32 | EXPORT_SYMBOL(memory_end); |
33 | |
34 | static struct pt_regs fake_regs = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
35 | 0, 0, 0, 0, 0, 0, |
36 | 0}; |
37 | |
38 | /* Copy a short hook instruction sequence to the exception address */ |
39 | static inline void copy_exception_handler(unsigned int addr) |
40 | { |
41 | unsigned int start = (unsigned int) exception_handler_hook; |
42 | volatile unsigned int tmp = 0; |
43 | |
44 | if (start == addr) { |
45 | /* The CPU exception address already points to the handler. */ |
46 | return; |
47 | } |
48 | |
49 | __asm__ __volatile__ ( |
50 | "ldw %2,0(%0)\n" |
51 | "stw %2,0(%1)\n" |
52 | "ldw %2,4(%0)\n" |
53 | "stw %2,4(%1)\n" |
54 | "ldw %2,8(%0)\n" |
55 | "stw %2,8(%1)\n" |
56 | "flushd 0(%1)\n" |
57 | "flushd 4(%1)\n" |
58 | "flushd 8(%1)\n" |
59 | "flushi %1\n" |
60 | "addi %1,%1,4\n" |
61 | "flushi %1\n" |
62 | "addi %1,%1,4\n" |
63 | "flushi %1\n" |
64 | "flushp\n" |
65 | : /* no output registers */ |
66 | : "r" (start), "r" (addr), "r" (tmp) |
67 | : "memory" |
68 | ); |
69 | } |
70 | |
71 | /* Copy the fast TLB miss handler */ |
72 | static inline void copy_fast_tlb_miss_handler(unsigned int addr) |
73 | { |
74 | unsigned int start = (unsigned int) fast_handler; |
75 | unsigned int end = (unsigned int) fast_handler_end; |
76 | volatile unsigned int tmp = 0; |
77 | |
78 | __asm__ __volatile__ ( |
79 | "1:\n" |
80 | " ldw %3,0(%0)\n" |
81 | " stw %3,0(%1)\n" |
82 | " flushd 0(%1)\n" |
83 | " flushi %1\n" |
84 | " flushp\n" |
85 | " addi %0,%0,4\n" |
86 | " addi %1,%1,4\n" |
87 | " bne %0,%2,1b\n" |
88 | : /* no output registers */ |
89 | : "r" (start), "r" (addr), "r" (end), "r" (tmp) |
90 | : "memory" |
91 | ); |
92 | } |
93 | |
94 | /* |
95 | * save args passed from u-boot, called from head.S |
96 | * |
97 | * @r4: NIOS magic |
98 | * @r5: initrd start |
99 | * @r6: initrd end or fdt |
100 | * @r7: kernel command line |
101 | */ |
102 | asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6, |
103 | unsigned r7) |
104 | { |
105 | unsigned dtb_passed = 0; |
106 | char cmdline_passed[COMMAND_LINE_SIZE] __maybe_unused = { 0, }; |
107 | |
108 | #if defined(CONFIG_NIOS2_PASS_CMDLINE) |
109 | if (r4 == 0x534f494e) { /* r4 is magic NIOS */ |
110 | #if defined(CONFIG_BLK_DEV_INITRD) |
111 | if (r5) { /* initramfs */ |
112 | initrd_start = r5; |
113 | initrd_end = r6; |
114 | } |
115 | #endif /* CONFIG_BLK_DEV_INITRD */ |
116 | dtb_passed = r6; |
117 | |
118 | if (r7) |
119 | strscpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE); |
120 | } |
121 | #endif |
122 | |
123 | early_init_devtree((void *)dtb_passed); |
124 | |
125 | #ifndef CONFIG_CMDLINE_FORCE |
126 | if (cmdline_passed[0]) |
127 | strscpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE); |
128 | #ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB |
129 | else |
130 | strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE); |
131 | #endif |
132 | #endif |
133 | |
134 | parse_early_param(); |
135 | } |
136 | |
137 | static void __init find_limits(unsigned long *min, unsigned long *max_low, |
138 | unsigned long *max_high) |
139 | { |
140 | *max_low = PFN_DOWN(memblock_get_current_limit()); |
141 | *min = PFN_UP(memblock_start_of_DRAM()); |
142 | *max_high = PFN_DOWN(memblock_end_of_DRAM()); |
143 | } |
144 | |
145 | void __init setup_arch(char **cmdline_p) |
146 | { |
147 | console_verbose(); |
148 | |
149 | memory_start = memblock_start_of_DRAM(); |
150 | memory_end = memblock_end_of_DRAM(); |
151 | |
152 | setup_initial_init_mm(start_code: _stext, end_code: _etext, end_data: _edata, brk: _end); |
153 | init_task.thread.kregs = &fake_regs; |
154 | |
155 | /* Keep a copy of command line */ |
156 | *cmdline_p = boot_command_line; |
157 | |
158 | find_limits(min: &min_low_pfn, max_low: &max_low_pfn, max_high: &max_pfn); |
159 | max_mapnr = max_low_pfn; |
160 | |
161 | memblock_reserve(__pa_symbol(_stext), size: _end - _stext); |
162 | #ifdef CONFIG_BLK_DEV_INITRD |
163 | if (initrd_start) { |
164 | memblock_reserve(virt_to_phys(address: (void *)initrd_start), |
165 | size: initrd_end - initrd_start); |
166 | } |
167 | #endif /* CONFIG_BLK_DEV_INITRD */ |
168 | |
169 | early_init_fdt_reserve_self(); |
170 | early_init_fdt_scan_reserved_mem(); |
171 | |
172 | unflatten_and_copy_device_tree(); |
173 | |
174 | setup_cpuinfo(); |
175 | |
176 | copy_exception_handler(addr: cpuinfo.exception_addr); |
177 | |
178 | mmu_init(); |
179 | |
180 | copy_fast_tlb_miss_handler(addr: cpuinfo.fast_tlb_miss_exc_addr); |
181 | |
182 | /* |
183 | * Initialize MMU context handling here because data from cpuinfo is |
184 | * needed for this. |
185 | */ |
186 | mmu_context_init(); |
187 | |
188 | /* |
189 | * get kmalloc into gear |
190 | */ |
191 | paging_init(); |
192 | } |
193 | |