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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/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#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
29unsigned long memory_start;
30EXPORT_SYMBOL(memory_start);
31
32unsigned long memory_end;
33EXPORT_SYMBOL(memory_end);
34
35unsigned long memory_size;
36
37static 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
42struct screen_info screen_info;
43#endif
44
45/* Copy a short hook instruction sequence to the exception address */
46static 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 */
79static 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 */
109asmlinkage 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 strlcpy(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 strlcpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);
135#ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB
136 else
137 strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
138#endif
139#endif
140
141 parse_early_param();
142}
143
144void __init setup_arch(char **cmdline_p)
145{
146 int dram_start;
147
148 console_verbose();
149
150 dram_start = memblock_start_of_DRAM();
151 memory_size = memblock_phys_mem_size();
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 memblock_reserve(dram_start, memory_start - dram_start);
169#ifdef CONFIG_BLK_DEV_INITRD
170 if (initrd_start) {
171 memblock_reserve(virt_to_phys((void *)initrd_start),
172 initrd_end - initrd_start);
173 }
174#endif /* CONFIG_BLK_DEV_INITRD */
175
176 early_init_fdt_reserve_self();
177 early_init_fdt_scan_reserved_mem();
178
179 unflatten_and_copy_device_tree();
180
181 setup_cpuinfo();
182
183 copy_exception_handler(cpuinfo.exception_addr);
184
185 mmu_init();
186
187 copy_fast_tlb_miss_handler(cpuinfo.fast_tlb_miss_exc_addr);
188
189 /*
190 * Initialize MMU context handling here because data from cpuinfo is
191 * needed for this.
192 */
193 mmu_context_init();
194
195 /*
196 * get kmalloc into gear
197 */
198 paging_init();
199
200#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
201 conswitchp = &dummy_con;
202#endif
203}
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}