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
  33 #include <asm/setup.h>
  34 #include <asm/sections.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/smp.h>
  37 #include <asm/sbi.h>
  38 #include <asm/tlbflush.h>
  39 #include <asm/thread_info.h>
  40
  41 #ifdef CONFIG_HVC_RISCV_SBI
  42 #include <asm/hvc_riscv_sbi.h>
  43 #endif
  44
  45 #ifdef CONFIG_DUMMY_CONSOLE
  46 struct screen_info screen_info = {
  47         .orig_video_lines       = 30,
  48         .orig_video_cols        = 80,
  49         .orig_video_mode        = 0,
  50         .orig_video_ega_bx      = 0,
  51         .orig_video_isVGA       = 1,
  52         .orig_video_points      = 8
  53 };
  54 #endif
  55
  56 #ifdef CONFIG_CMDLINE_BOOL
  57 static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
  58 #endif /* CONFIG_CMDLINE_BOOL */
  59
  60 unsigned long va_pa_offset;
  61 EXPORT_SYMBOL(va_pa_offset);
  62 unsigned long pfn_base;
  63 EXPORT_SYMBOL(pfn_base);
  64
  65 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  66 EXPORT_SYMBOL(empty_zero_page);
  67
  68 /* The lucky hart to first increment this variable will boot the other cores */
  69 atomic_t hart_lottery;
  70
  71 #ifdef CONFIG_BLK_DEV_INITRD
  72 static void __init setup_initrd(void)
  73 {
  74         extern char __initramfs_start[];
  75         extern unsigned long __initramfs_size;
  76         unsigned long size;
  77
  78         if (__initramfs_size > 0) {
  79                 initrd_start = (unsigned long)(&__initramfs_start);
  80                 initrd_end = initrd_start + __initramfs_size;
  81         }
  82
  83         if (initrd_start >= initrd_end) {
  84                 printk(KERN_INFO "initrd not found or empty");
  85                 goto disable;
  86         }
  87         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  88                 printk(KERN_ERR "initrd extends beyond end of memory");
  89                 goto disable;
  90         }
  91
  92         size =  initrd_end - initrd_start;
  93         memblock_reserve(__pa(initrd_start), size);
  94         initrd_below_start_ok = 1;
  95
  96         printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
  97                 (void *)(initrd_start), size);
  98         return;
  99 disable:
 100         pr_cont(" - disabling initrd\n");
 101         initrd_start = 0;
 102         initrd_end = 0;
 103 }
 104 #endif /* CONFIG_BLK_DEV_INITRD */
 105
 106 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 107 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 108
 109 #ifndef __PAGETABLE_PMD_FOLDED
 110 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 111 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 112 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 113 #endif
 114
 115 asmlinkage void __init setup_vm(void)
 116 {
 117         extern char _start;
 118         uintptr_t i;
 119         uintptr_t pa = (uintptr_t) &_start;
 120         pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
 121
 122         va_pa_offset = PAGE_OFFSET - pa;
 123         pfn_base = PFN_DOWN(pa);
 124
 125         /* Sanity check alignment and size */
 126         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 127         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
 128
 129 #ifndef __PAGETABLE_PMD_FOLDED
 130         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 131                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 132                         __pgprot(_PAGE_TABLE));
 133         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
 134
 135         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 136                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 137                 swapper_pg_dir[o] =
 138                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 139                                 __pgprot(_PAGE_TABLE));
 140         }
 141         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 142                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
 143 #else
 144         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 145                 pfn_pgd(PFN_DOWN(pa), prot);
 146
 147         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 148                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 149                 swapper_pg_dir[o] =
 150                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 151         }
 152 #endif
 153 }
 154
 155 void __init sbi_save(unsigned int hartid, void *dtb)
 156 {
 157         early_init_dt_scan(__va(dtb));
 158 }
 159
 160 /*
 161  * Allow the user to manually add a memory region (in case DTS is broken);
 162  * "mem_end=nn[KkMmGg]"
 163  */
 164 static int __init mem_end_override(char *p)
 165 {
 166         resource_size_t base, end;
 167
 168         if (!p)
 169                 return -EINVAL;
 170         base = (uintptr_t) __pa(PAGE_OFFSET);
 171         end = memparse(p, &p) & PMD_MASK;
 172         if (end == 0)
 173                 return -EINVAL;
 174         memblock_add(base, end - base);
 175         return 0;
 176 }
 177 early_param("mem_end", mem_end_override);
 178
 179 static void __init setup_bootmem(void)
 180 {
 181         struct memblock_region *reg;
 182         phys_addr_t mem_size = 0;
 183
 184         /* Find the memory region containing the kernel */
 185         for_each_memblock(memory, reg) {
 186                 phys_addr_t vmlinux_end = __pa(_end);
 187                 phys_addr_t end = reg->base + reg->size;
 188
 189                 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 190                         /*
 191                          * Reserve from the start of the region to the end of
 192                          * the kernel
 193                          */
 194                         memblock_reserve(reg->base, vmlinux_end - reg->base);
 195                         mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 196                 }
 197         }
 198         BUG_ON(mem_size == 0);
 199
 200         set_max_mapnr(PFN_DOWN(mem_size));
 201         max_low_pfn = pfn_base + PFN_DOWN(mem_size);
 202
 203 #ifdef CONFIG_BLK_DEV_INITRD
 204         setup_initrd();
 205 #endif /* CONFIG_BLK_DEV_INITRD */
 206
 207         early_init_fdt_reserve_self();
 208         early_init_fdt_scan_reserved_mem();
 209         memblock_allow_resize();
 210         memblock_dump_all();
 211 }
 212
 213 void __init setup_arch(char **cmdline_p)
 214 {
 215 #if defined(CONFIG_HVC_RISCV_SBI)
 216         if (likely(early_console == NULL)) {
 217                 early_console = &riscv_sbi_early_console_dev;
 218                 register_console(early_console);
 219         }
 220 #endif
 221
 222 #ifdef CONFIG_CMDLINE_BOOL
 223 #ifdef CONFIG_CMDLINE_OVERRIDE
 224         strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
 225 #else
 226         if (builtin_cmdline[0] != '\0') {
 227                 /* Append bootloader command line to built-in */
 228                 strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
 229                 strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 230                 strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
 231         }
 232 #endif /* CONFIG_CMDLINE_OVERRIDE */
 233 #endif /* CONFIG_CMDLINE_BOOL */
 234         *cmdline_p = boot_command_line;
 235
 236         parse_early_param();
 237
 238         init_mm.start_code = (unsigned long) _stext;
 239         init_mm.end_code   = (unsigned long) _etext;
 240         init_mm.end_data   = (unsigned long) _edata;
 241         init_mm.brk        = (unsigned long) _end;
 242
 243         setup_bootmem();
 244         paging_init();
 245         unflatten_device_tree();
 246
 247 #ifdef CONFIG_SMP
 248         setup_smp();
 249 #endif
 250
 251 #ifdef CONFIG_DUMMY_CONSOLE
 252         conswitchp = &dummy_con;
 253 #endif
 254
 255         riscv_fill_hwcap();
 256 }
 257
 258 static int __init riscv_device_init(void)
 259 {
 260         return of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 261 }
 262 subsys_initcall_sync(riscv_device_init);