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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 unflatten_and_copy_device_tree();
199
200 setup_cpuinfo();
201
202 copy_exception_handler(cpuinfo.exception_addr);
203
204 mmu_init();
205
206 copy_fast_tlb_miss_handler(cpuinfo.fast_tlb_miss_exc_addr);
207
208 /*
209 * Initialize MMU context handling here because data from cpuinfo is
210 * needed for this.
211 */
212 mmu_context_init();
213
214 /*
215 * get kmalloc into gear
216 */
217 paging_init();
218
219#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
220 conswitchp = &dummy_con;
221#endif
222}
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
28unsigned long memory_start;
29EXPORT_SYMBOL(memory_start);
30
31unsigned long memory_end;
32EXPORT_SYMBOL(memory_end);
33
34static 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 */
39static 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 */
72static 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 */
102asmlinkage 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
137static 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
145void __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(_stext, _etext, _edata, _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_low_pfn, &max_low_pfn, &max_pfn);
159 max_mapnr = max_low_pfn;
160
161 memblock_reserve(__pa_symbol(_stext), _end - _stext);
162#ifdef CONFIG_BLK_DEV_INITRD
163 if (initrd_start) {
164 memblock_reserve(virt_to_phys((void *)initrd_start),
165 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(cpuinfo.exception_addr);
177
178 mmu_init();
179
180 copy_fast_tlb_miss_handler(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}