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/init.h>
  23 #include <linux/mm.h>
  24 #include <linux/memblock.h>
  25 #include <linux/sched.h>
  26 #include <linux/initrd.h>
  27 #include <linux/console.h>
  28 #include <linux/screen_info.h>
  29 #include <linux/of_fdt.h>
  30 #include <linux/of_platform.h>
  31 #include <linux/sched/task.h>
  32 #include <linux/swiotlb.h>
  33
  34 #include <asm/setup.h>
  35 #include <asm/sections.h>
  36 #include <asm/pgtable.h>
  37 #include <asm/smp.h>
  38 #include <asm/sbi.h>
  39 #include <asm/tlbflush.h>
  40 #include <asm/thread_info.h>
  41
  42 #ifdef CONFIG_EARLY_PRINTK
  43 static void sbi_console_write(struct console *co, const char *buf,
  44                               unsigned int n)
  45 {
  46         int i;
  47
  48         for (i = 0; i < n; ++i) {
  49                 if (buf[i] == '\n')
  50                         sbi_console_putchar('\r');
  51                 sbi_console_putchar(buf[i]);
  52         }
  53 }
  54
  55 struct console riscv_sbi_early_console_dev __initdata = {
  56         .name   = "early",
  57         .write  = sbi_console_write,
  58         .flags  = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
  59         .index  = -1
  60 };
  61 #endif
  62
  63 #ifdef CONFIG_DUMMY_CONSOLE
  64 struct screen_info screen_info = {
  65         .orig_video_lines       = 30,
  66         .orig_video_cols        = 80,
  67         .orig_video_mode        = 0,
  68         .orig_video_ega_bx      = 0,
  69         .orig_video_isVGA       = 1,
  70         .orig_video_points      = 8
  71 };
  72 #endif
  73
  74 unsigned long va_pa_offset;
  75 EXPORT_SYMBOL(va_pa_offset);
  76 unsigned long pfn_base;
  77 EXPORT_SYMBOL(pfn_base);
  78
  79 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  80 EXPORT_SYMBOL(empty_zero_page);
  81
  82 /* The lucky hart to first increment this variable will boot the other cores */
  83 atomic_t hart_lottery;
  84
  85 #ifdef CONFIG_BLK_DEV_INITRD
  86 static void __init setup_initrd(void)
  87 {
  88         extern char __initramfs_start[];
  89         extern unsigned long __initramfs_size;
  90         unsigned long size;
  91
  92         if (__initramfs_size > 0) {
  93                 initrd_start = (unsigned long)(&__initramfs_start);
  94                 initrd_end = initrd_start + __initramfs_size;
  95         }
  96
  97         if (initrd_start >= initrd_end) {
  98                 printk(KERN_INFO "initrd not found or empty");
  99                 goto disable;
 100         }
 101         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
 102                 printk(KERN_ERR "initrd extends beyond end of memory");
 103                 goto disable;
 104         }
 105
 106         size =  initrd_end - initrd_start;
 107         memblock_reserve(__pa(initrd_start), size);
 108         initrd_below_start_ok = 1;
 109
 110         printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
 111                 (void *)(initrd_start), size);
 112         return;
 113 disable:
 114         pr_cont(" - disabling initrd\n");
 115         initrd_start = 0;
 116         initrd_end = 0;
 117 }
 118 #endif /* CONFIG_BLK_DEV_INITRD */
 119
 120 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 121 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 122
 123 #ifndef __PAGETABLE_PMD_FOLDED
 124 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 125 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 126 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 127 #endif
 128
 129 asmlinkage void __init setup_vm(void)
 130 {
 131         extern char _start;
 132         uintptr_t i;
 133         uintptr_t pa = (uintptr_t) &_start;
 134         pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
 135
 136         va_pa_offset = PAGE_OFFSET - pa;
 137         pfn_base = PFN_DOWN(pa);
 138
 139         /* Sanity check alignment and size */
 140         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 141         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
 142
 143 #ifndef __PAGETABLE_PMD_FOLDED
 144         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 145                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 146                         __pgprot(_PAGE_TABLE));
 147         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
 148
 149         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 150                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 151                 swapper_pg_dir[o] =
 152                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 153                                 __pgprot(_PAGE_TABLE));
 154         }
 155         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 156                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
 157 #else
 158         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 159                 pfn_pgd(PFN_DOWN(pa), prot);
 160
 161         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 162                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 163                 swapper_pg_dir[o] =
 164                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 165         }
 166 #endif
 167 }
 168
 169 void __init parse_dtb(unsigned int hartid, void *dtb)
 170 {
 171         early_init_dt_scan(__va(dtb));
 172 }
 173
 174 static void __init setup_bootmem(void)
 175 {
 176         struct memblock_region *reg;
 177         phys_addr_t mem_size = 0;
 178
 179         /* Find the memory region containing the kernel */
 180         for_each_memblock(memory, reg) {
 181                 phys_addr_t vmlinux_end = __pa(_end);
 182                 phys_addr_t end = reg->base + reg->size;
 183
 184                 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 185                         /*
 186                          * Reserve from the start of the region to the end of
 187                          * the kernel
 188                          */
 189                         memblock_reserve(reg->base, vmlinux_end - reg->base);
 190                         mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 191                 }
 192         }
 193         BUG_ON(mem_size == 0);
 194
 195         set_max_mapnr(PFN_DOWN(mem_size));
 196         max_low_pfn = pfn_base + PFN_DOWN(mem_size);
 197
 198 #ifdef CONFIG_BLK_DEV_INITRD
 199         setup_initrd();
 200 #endif /* CONFIG_BLK_DEV_INITRD */
 201
 202         early_init_fdt_reserve_self();
 203         early_init_fdt_scan_reserved_mem();
 204         memblock_allow_resize();
 205         memblock_dump_all();
 206
 207         for_each_memblock(memory, reg) {
 208                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
 209                 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
 210
 211                 memblock_set_node(PFN_PHYS(start_pfn),
 212                                   PFN_PHYS(end_pfn - start_pfn),
 213                                   &memblock.memory, 0);
 214         }
 215 }
 216
 217 void __init setup_arch(char **cmdline_p)
 218 {
 219 #if defined(CONFIG_EARLY_PRINTK)
 220        if (likely(early_console == NULL)) {
 221                early_console = &riscv_sbi_early_console_dev;
 222                register_console(early_console);
 223        }
 224 #endif
 225         *cmdline_p = boot_command_line;
 226
 227         parse_early_param();
 228
 229         init_mm.start_code = (unsigned long) _stext;
 230         init_mm.end_code   = (unsigned long) _etext;
 231         init_mm.end_data   = (unsigned long) _edata;
 232         init_mm.brk        = (unsigned long) _end;
 233
 234         setup_bootmem();
 235         paging_init();
 236         unflatten_device_tree();
 237         swiotlb_init(1);
 238
 239 #ifdef CONFIG_SMP
 240         setup_smp();
 241 #endif
 242
 243 #ifdef CONFIG_DUMMY_CONSOLE
 244         conswitchp = &dummy_con;
 245 #endif
 246
 247         riscv_fill_hwcap();
 248 }
 249