1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4 #include <linux/console.h>
5 #include <linux/memblock.h>
6 #include <linux/initrd.h>
7 #include <linux/of.h>
8 #include <linux/of_fdt.h>
9 #include <linux/start_kernel.h>
10 #include <linux/dma-map-ops.h>
11 #include <linux/screen_info.h>
12 #include <asm/sections.h>
13 #include <asm/mmu_context.h>
14 #include <asm/pgalloc.h>
15
16 #ifdef CONFIG_DUMMY_CONSOLE
17 struct screen_info screen_info = {
18 .orig_video_lines = 30,
19 .orig_video_cols = 80,
20 .orig_video_mode = 0,
21 .orig_video_ega_bx = 0,
22 .orig_video_isVGA = 1,
23 .orig_video_points = 8
24 };
25 #endif
26
csky_memblock_init(void)27 static void __init csky_memblock_init(void)
28 {
29 unsigned long lowmem_size = PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
30 unsigned long sseg_size = PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET);
31 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
32 signed long size;
33
34 memblock_reserve(__pa(_start), _end - _start);
35
36 early_init_fdt_reserve_self();
37 early_init_fdt_scan_reserved_mem();
38
39 memblock_dump_all();
40
41 min_low_pfn = PFN_UP(memblock_start_of_DRAM());
42 max_low_pfn = max_pfn = PFN_DOWN(memblock_end_of_DRAM());
43
44 size = max_pfn - min_low_pfn;
45
46 if (size >= lowmem_size) {
47 max_low_pfn = min_low_pfn + lowmem_size;
48 #ifdef CONFIG_PAGE_OFFSET_80000000
49 write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE);
50 #endif
51 } else if (size > sseg_size) {
52 max_low_pfn = min_low_pfn + sseg_size;
53 }
54
55 max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
56
57 mmu_init(min_low_pfn, max_low_pfn);
58
59 #ifdef CONFIG_HIGHMEM
60 max_zone_pfn[ZONE_HIGHMEM] = max_pfn;
61
62 highstart_pfn = max_low_pfn;
63 highend_pfn = max_pfn;
64 #endif
65 memblock_set_current_limit(PFN_PHYS(max_low_pfn));
66
67 dma_contiguous_reserve(0);
68
69 free_area_init(max_zone_pfn);
70 }
71
setup_arch(char ** cmdline_p)72 void __init setup_arch(char **cmdline_p)
73 {
74 *cmdline_p = boot_command_line;
75
76 console_verbose();
77
78 pr_info("Phys. mem: %ldMB\n",
79 (unsigned long) memblock_phys_mem_size()/1024/1024);
80
81 setup_initial_init_mm(_start, _etext, _edata, _end);
82
83 parse_early_param();
84
85 csky_memblock_init();
86
87 unflatten_and_copy_device_tree();
88
89 #ifdef CONFIG_SMP
90 setup_smp();
91 #endif
92
93 sparse_init();
94
95 fixaddr_init();
96
97 #ifdef CONFIG_HIGHMEM
98 kmap_init();
99 #endif
100 }
101
102 unsigned long va_pa_offset;
103 EXPORT_SYMBOL(va_pa_offset);
104
read_mmu_msa(void)105 static inline unsigned long read_mmu_msa(void)
106 {
107 #ifdef CONFIG_PAGE_OFFSET_80000000
108 return read_mmu_msa0();
109 #endif
110
111 #ifdef CONFIG_PAGE_OFFSET_A0000000
112 return read_mmu_msa1();
113 #endif
114 }
115
csky_start(unsigned int unused,void * dtb_start)116 asmlinkage __visible void __init csky_start(unsigned int unused,
117 void *dtb_start)
118 {
119 /* Clean up bss section */
120 memset(__bss_start, 0, __bss_stop - __bss_start);
121
122 va_pa_offset = read_mmu_msa() & ~(SSEG_SIZE - 1);
123
124 pre_trap_init();
125
126 if (dtb_start == NULL)
127 early_init_dt_scan(__dtb_start);
128 else
129 early_init_dt_scan(dtb_start);
130
131 start_kernel();
132
133 asm volatile("br .\n");
134 }
135