arch/csky/kernel/setup.c

   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-contiguous.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 zone_size[MAX_NR_ZONES];
  30         signed long size;
  31
  32         memblock_reserve(__pa(_stext), _end - _stext);
  33 #ifdef CONFIG_BLK_DEV_INITRD
  34         memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
  35 #endif
  36
  37         early_init_fdt_reserve_self();
  38         early_init_fdt_scan_reserved_mem();
  39
  40         memblock_dump_all();
  41
  42         memset(zone_size, 0, sizeof(zone_size));
  43
  44         min_low_pfn = PFN_UP(memblock_start_of_DRAM());
  45         max_low_pfn = max_pfn = PFN_DOWN(memblock_end_of_DRAM());
  46
  47         size = max_pfn - min_low_pfn;
  48
  49         if (size <= PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET))
  50                 zone_size[ZONE_NORMAL] = size;
  51         else if (size < PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET)) {
  52                 zone_size[ZONE_NORMAL] =
  53                                 PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET);
  54                 max_low_pfn = min_low_pfn + zone_size[ZONE_NORMAL];
  55         } else {
  56                 zone_size[ZONE_NORMAL] =
  57                                 PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
  58                 max_low_pfn = min_low_pfn + zone_size[ZONE_NORMAL];
  59                 write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE);
  60         }
  61
  62 #ifdef CONFIG_HIGHMEM
  63         zone_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
  64
  65         highstart_pfn = max_low_pfn;
  66         highend_pfn   = max_pfn;
  67 #endif
  68         memblock_set_current_limit(PFN_PHYS(max_low_pfn));
  69
  70         dma_contiguous_reserve(0);
  71
  72         free_area_init_node(0, zone_size, min_low_pfn, NULL);
  73 }
  74
  75 void __init setup_arch(char **cmdline_p)
  76 {
  77         *cmdline_p = boot_command_line;
  78
  79         console_verbose();
  80
  81         pr_info("Phys. mem: %ldMB\n",
  82                 (unsigned long) memblock_phys_mem_size()/1024/1024);
  83
  84         init_mm.start_code = (unsigned long) _stext;
  85         init_mm.end_code = (unsigned long) _etext;
  86         init_mm.end_data = (unsigned long) _edata;
  87         init_mm.brk = (unsigned long) _end;
  88
  89         parse_early_param();
  90
  91         csky_memblock_init();
  92
  93         unflatten_and_copy_device_tree();
  94
  95 #ifdef CONFIG_SMP
  96         setup_smp();
  97 #endif
  98
  99         sparse_init();
 100
 101 #ifdef CONFIG_HIGHMEM
 102         kmap_init();
 103 #endif
 104
 105 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
 106         conswitchp = &dummy_con;
 107 #endif
 108 }
 109
 110 unsigned long va_pa_offset;
 111 EXPORT_SYMBOL(va_pa_offset);
 112
 113 asmlinkage __visible void __init csky_start(unsigned int unused,
 114                                             void *dtb_start)
 115 {
 116         /* Clean up bss section */
 117         memset(__bss_start, 0, __bss_stop - __bss_start);
 118
 119         va_pa_offset = read_mmu_msa0() & ~(SSEG_SIZE - 1);
 120
 121         pre_trap_init();
 122         pre_mmu_init();
 123
 124         if (dtb_start == NULL)
 125                 early_init_dt_scan(__dtb_start);
 126         else
 127                 early_init_dt_scan(dtb_start);
 128
 129         start_kernel();
 130
 131         asm volatile("br .\n");
 132 }