arch/riscv/kernel/setup.c

   1 /*
   2  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
   3  *  Chen Liqin <liqin.chen@sunplusct.com>
   4  *  Lennox Wu <lennox.wu@sunplusct.com>
   5  * Copyright (C) 2012 Regents of the University of California
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see the file COPYING, or write
  19  * to the Free Software Foundation, Inc.,
  20  */
  21
  22 #include <linux/bootmem.h>
  23 #include <linux/init.h>
  24 #include <linux/mm.h>
  25 #include <linux/memblock.h>
  26 #include <linux/sched.h>
  27 #include <linux/initrd.h>
  28 #include <linux/console.h>
  29 #include <linux/screen_info.h>
  30 #include <linux/of_fdt.h>
  31 #include <linux/of_platform.h>
  32 #include <linux/sched/task.h>
  33 #include <linux/swiotlb.h>
  34
  35 #include <asm/setup.h>
  36 #include <asm/sections.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/smp.h>
  39 #include <asm/sbi.h>
  40 #include <asm/tlbflush.h>
  41 #include <asm/thread_info.h>
  42
  43 #ifdef CONFIG_EARLY_PRINTK
  44 static void sbi_console_write(struct console *co, const char *buf,
  45                               unsigned int n)
  46 {
  47         int i;
  48
  49         for (i = 0; i < n; ++i) {
  50                 if (buf[i] == '\n')
  51                         sbi_console_putchar('\r');
  52                 sbi_console_putchar(buf[i]);
  53         }
  54 }
  55
  56 struct console riscv_sbi_early_console_dev __initdata = {
  57         .name   = "early",
  58         .write  = sbi_console_write,
  59         .flags  = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
  60         .index  = -1
  61 };
  62 #endif
  63
  64 #ifdef CONFIG_DUMMY_CONSOLE
  65 struct screen_info screen_info = {
  66         .orig_video_lines       = 30,
  67         .orig_video_cols        = 80,
  68         .orig_video_mode        = 0,
  69         .orig_video_ega_bx      = 0,
  70         .orig_video_isVGA       = 1,
  71         .orig_video_points      = 8
  72 };
  73 #endif
  74
  75 unsigned long va_pa_offset;
  76 EXPORT_SYMBOL(va_pa_offset);
  77 unsigned long pfn_base;
  78 EXPORT_SYMBOL(pfn_base);
  79
  80 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  81 EXPORT_SYMBOL(empty_zero_page);
  82
  83 /* The lucky hart to first increment this variable will boot the other cores */
  84 atomic_t hart_lottery;
  85
  86 #ifdef CONFIG_BLK_DEV_INITRD
  87 static void __init setup_initrd(void)
  88 {
  89         unsigned long size;
  90
  91         if (initrd_start >= initrd_end) {
  92                 printk(KERN_INFO "initrd not found or empty");
  93                 goto disable;
  94         }
  95         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  96                 printk(KERN_ERR "initrd extends beyond end of memory");
  97                 goto disable;
  98         }
  99
 100         size =  initrd_end - initrd_start;
 101         memblock_reserve(__pa(initrd_start), size);
 102         initrd_below_start_ok = 1;
 103
 104         printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
 105                 (void *)(initrd_start), size);
 106         return;
 107 disable:
 108         pr_cont(" - disabling initrd\n");
 109         initrd_start = 0;
 110         initrd_end = 0;
 111 }
 112 #endif /* CONFIG_BLK_DEV_INITRD */
 113
 114 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 115 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 116
 117 #ifndef __PAGETABLE_PMD_FOLDED
 118 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 119 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 120 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 121 #endif
 122
 123 asmlinkage void __init setup_vm(void)
 124 {
 125         extern char _start;
 126         uintptr_t i;
 127         uintptr_t pa = (uintptr_t) &_start;
 128         pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
 129
 130         va_pa_offset = PAGE_OFFSET - pa;
 131         pfn_base = PFN_DOWN(pa);
 132
 133         /* Sanity check alignment and size */
 134         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 135         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
 136
 137 #ifndef __PAGETABLE_PMD_FOLDED
 138         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 139                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 140                         __pgprot(_PAGE_TABLE));
 141         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
 142
 143         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 144                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 145                 swapper_pg_dir[o] =
 146                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 147                                 __pgprot(_PAGE_TABLE));
 148         }
 149         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 150                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
 151 #else
 152         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 153                 pfn_pgd(PFN_DOWN(pa), prot);
 154
 155         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 156                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 157                 swapper_pg_dir[o] =
 158                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 159         }
 160 #endif
 161 }
 162
 163 void __init parse_dtb(unsigned int hartid, void *dtb)
 164 {
 165         early_init_dt_scan(__va(dtb));
 166 }
 167
 168 static void __init setup_bootmem(void)
 169 {
 170         struct memblock_region *reg;
 171         phys_addr_t mem_size = 0;
 172
 173         /* Find the memory region containing the kernel */
 174         for_each_memblock(memory, reg) {
 175                 phys_addr_t vmlinux_end = __pa(_end);
 176                 phys_addr_t end = reg->base + reg->size;
 177
 178                 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 179                         /*
 180                          * Reserve from the start of the region to the end of
 181                          * the kernel
 182                          */
 183                         memblock_reserve(reg->base, vmlinux_end - reg->base);
 184                         mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 185                 }
 186         }
 187         BUG_ON(mem_size == 0);
 188
 189         set_max_mapnr(PFN_DOWN(mem_size));
 190         max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
 191         max_pfn = max_low_pfn;
 192
 193 #ifdef CONFIG_BLK_DEV_INITRD
 194         setup_initrd();
 195 #endif /* CONFIG_BLK_DEV_INITRD */
 196
 197         early_init_fdt_reserve_self();
 198         early_init_fdt_scan_reserved_mem();
 199         memblock_allow_resize();
 200         memblock_dump_all();
 201
 202         for_each_memblock(memory, reg) {
 203                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
 204                 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
 205
 206                 memblock_set_node(PFN_PHYS(start_pfn),
 207                                   PFN_PHYS(end_pfn - start_pfn),
 208                                   &memblock.memory, 0);
 209         }
 210 }
 211
 212 void __init setup_arch(char **cmdline_p)
 213 {
 214 #if defined(CONFIG_EARLY_PRINTK)
 215        if (likely(early_console == NULL)) {
 216                early_console = &riscv_sbi_early_console_dev;
 217                register_console(early_console);
 218        }
 219 #endif
 220         *cmdline_p = boot_command_line;
 221
 222         parse_early_param();
 223
 224         init_mm.start_code = (unsigned long) _stext;
 225         init_mm.end_code   = (unsigned long) _etext;
 226         init_mm.end_data   = (unsigned long) _edata;
 227         init_mm.brk        = (unsigned long) _end;
 228
 229         setup_bootmem();
 230         paging_init();
 231         unflatten_device_tree();
 232         swiotlb_init(1);
 233
 234 #ifdef CONFIG_SMP
 235         setup_smp();
 236 #endif
 237
 238 #ifdef CONFIG_DUMMY_CONSOLE
 239         conswitchp = &dummy_con;
 240 #endif
 241
 242         riscv_fill_hwcap();
 243 }
 244