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 unsigned long pfn_base;
  62
  63 /* The lucky hart to first increment this variable will boot the other cores */
  64 atomic_t hart_lottery;
  65
  66 #ifdef CONFIG_BLK_DEV_INITRD
  67 static void __init setup_initrd(void)
  68 {
  69         extern char __initramfs_start[];
  70         extern unsigned long __initramfs_size;
  71         unsigned long size;
  72
  73         if (__initramfs_size > 0) {
  74                 initrd_start = (unsigned long)(&__initramfs_start);
  75                 initrd_end = initrd_start + __initramfs_size;
  76         }
  77
  78         if (initrd_start >= initrd_end) {
  79                 printk(KERN_INFO "initrd not found or empty");
  80                 goto disable;
  81         }
  82         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  83                 printk(KERN_ERR "initrd extends beyond end of memory");
  84                 goto disable;
  85         }
  86
  87         size =  initrd_end - initrd_start;
  88         memblock_reserve(__pa(initrd_start), size);
  89         initrd_below_start_ok = 1;
  90
  91         printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
  92                 (void *)(initrd_start), size);
  93         return;
  94 disable:
  95         pr_cont(" - disabling initrd\n");
  96         initrd_start = 0;
  97         initrd_end = 0;
  98 }
  99 #endif /* CONFIG_BLK_DEV_INITRD */
 100
 101 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 102 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 103
 104 #ifndef __PAGETABLE_PMD_FOLDED
 105 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 106 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 107 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 108 #endif
 109
 110 asmlinkage void __init setup_vm(void)
 111 {
 112         extern char _start;
 113         uintptr_t i;
 114         uintptr_t pa = (uintptr_t) &_start;
 115         pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
 116
 117         va_pa_offset = PAGE_OFFSET - pa;
 118         pfn_base = PFN_DOWN(pa);
 119
 120         /* Sanity check alignment and size */
 121         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 122         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
 123
 124 #ifndef __PAGETABLE_PMD_FOLDED
 125         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 126                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 127                         __pgprot(_PAGE_TABLE));
 128         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
 129
 130         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 131                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 132                 swapper_pg_dir[o] =
 133                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 134                                 __pgprot(_PAGE_TABLE));
 135         }
 136         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 137                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
 138 #else
 139         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 140                 pfn_pgd(PFN_DOWN(pa), prot);
 141
 142         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 143                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 144                 swapper_pg_dir[o] =
 145                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 146         }
 147 #endif
 148 }
 149
 150 void __init sbi_save(unsigned int hartid, void *dtb)
 151 {
 152         early_init_dt_scan(__va(dtb));
 153 }
 154
 155 /*
 156  * Allow the user to manually add a memory region (in case DTS is broken);
 157  * "mem_end=nn[KkMmGg]"
 158  */
 159 static int __init mem_end_override(char *p)
 160 {
 161         resource_size_t base, end;
 162
 163         if (!p)
 164                 return -EINVAL;
 165         base = (uintptr_t) __pa(PAGE_OFFSET);
 166         end = memparse(p, &p) & PMD_MASK;
 167         if (end == 0)
 168                 return -EINVAL;
 169         memblock_add(base, end - base);
 170         return 0;
 171 }
 172 early_param("mem_end", mem_end_override);
 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
 208 void __init setup_arch(char **cmdline_p)
 209 {
 210 #if defined(CONFIG_HVC_RISCV_SBI)
 211         if (likely(early_console == NULL)) {
 212                 early_console = &riscv_sbi_early_console_dev;
 213                 register_console(early_console);
 214         }
 215 #endif
 216
 217 #ifdef CONFIG_CMDLINE_BOOL
 218 #ifdef CONFIG_CMDLINE_OVERRIDE
 219         strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
 220 #else
 221         if (builtin_cmdline[0] != '\0') {
 222                 /* Append bootloader command line to built-in */
 223                 strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
 224                 strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 225                 strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
 226         }
 227 #endif /* CONFIG_CMDLINE_OVERRIDE */
 228 #endif /* CONFIG_CMDLINE_BOOL */
 229         *cmdline_p = boot_command_line;
 230
 231         parse_early_param();
 232
 233         init_mm.start_code = (unsigned long) _stext;
 234         init_mm.end_code   = (unsigned long) _etext;
 235         init_mm.end_data   = (unsigned long) _edata;
 236         init_mm.brk        = (unsigned long) _end;
 237
 238         setup_bootmem();
 239         paging_init();
 240         unflatten_device_tree();
 241
 242 #ifdef CONFIG_SMP
 243         setup_smp();
 244 #endif
 245
 246 #ifdef CONFIG_DUMMY_CONSOLE
 247         conswitchp = &dummy_con;
 248 #endif
 249
 250         riscv_fill_hwcap();
 251 }
 252
 253 static int __init riscv_device_init(void)
 254 {
 255         return of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 256 }
 257 subsys_initcall_sync(riscv_device_init);