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