LXR linux/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-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
  17struct 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
  27static 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(_stext), _end - _stext);
  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
  72void __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(_stext, _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
 102unsigned long va_pa_offset;
 103EXPORT_SYMBOL(va_pa_offset);
 104
 105static 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
 116asmlinkage __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