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 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 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); 104 105 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 } 115 116 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