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
 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		write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE);
 49	} else if (size > sseg_size) {
 50		max_low_pfn = min_low_pfn + sseg_size;
 51	}
 52
 53	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
 54
 55#ifdef CONFIG_HIGHMEM
 56	max_zone_pfn[ZONE_HIGHMEM] = max_pfn;
 57
 58	highstart_pfn = max_low_pfn;
 59	highend_pfn   = max_pfn;
 60#endif
 61	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
 62
 63	dma_contiguous_reserve(0);
 64
 65	free_area_init(max_zone_pfn);
 66}
 67
 68void __init setup_arch(char **cmdline_p)
 69{
 70	*cmdline_p = boot_command_line;
 71
 72	console_verbose();
 73
 74	pr_info("Phys. mem: %ldMB\n",
 75		(unsigned long) memblock_phys_mem_size()/1024/1024);
 76
 77	init_mm.start_code = (unsigned long) _stext;
 78	init_mm.end_code = (unsigned long) _etext;
 79	init_mm.end_data = (unsigned long) _edata;
 80	init_mm.brk = (unsigned long) _end;
 81
 82	parse_early_param();
 83
 84	csky_memblock_init();
 85
 86	unflatten_and_copy_device_tree();
 87
 88#ifdef CONFIG_SMP
 89	setup_smp();
 90#endif
 91
 92	sparse_init();
 93
 94	fixaddr_init();
 95
 96#ifdef CONFIG_HIGHMEM
 97	kmap_init();
 98#endif
 99}
100
101unsigned long va_pa_offset;
102EXPORT_SYMBOL(va_pa_offset);
103
104asmlinkage __visible void __init csky_start(unsigned int unused,
105					    void *dtb_start)
106{
107	/* Clean up bss section */
108	memset(__bss_start, 0, __bss_stop - __bss_start);
109
110	va_pa_offset = read_mmu_msa0() & ~(SSEG_SIZE - 1);
111
112	pre_trap_init();
113	pre_mmu_init();
114
115	if (dtb_start == NULL)
116		early_init_dt_scan(__dtb_start);
117	else
118		early_init_dt_scan(dtb_start);
119
120	start_kernel();
121
122	asm volatile("br .\n");
123}