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 unsigned long va_pa_offset;
  53 EXPORT_SYMBOL(va_pa_offset);
  54 unsigned long pfn_base;
  55 EXPORT_SYMBOL(pfn_base);
  56
  57 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  58 EXPORT_SYMBOL(empty_zero_page);
  59
  60 /* The lucky hart to first increment this variable will boot the other cores */
  61 atomic_t hart_lottery;
  62
  63 #ifdef CONFIG_BLK_DEV_INITRD
  64 static void __init setup_initrd(void)
  65 {
  66         extern char __initramfs_start[];
  67         extern unsigned long __initramfs_size;
  68         unsigned long size;
  69
  70         if (__initramfs_size > 0) {
  71                 initrd_start = (unsigned long)(&__initramfs_start);
  72                 initrd_end = initrd_start + __initramfs_size;
  73         }
  74
  75         if (initrd_start >= initrd_end) {
  76                 printk(KERN_INFO "initrd not found or empty");
  77                 goto disable;
  78         }
  79         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  80                 printk(KERN_ERR "initrd extends beyond end of memory");
  81                 goto disable;
  82         }
  83
  84         size =  initrd_end - initrd_start;
  85         memblock_reserve(__pa(initrd_start), size);
  86         initrd_below_start_ok = 1;
  87
  88         printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
  89                 (void *)(initrd_start), size);
  90         return;
  91 disable:
  92         pr_cont(" - disabling initrd\n");
  93         initrd_start = 0;
  94         initrd_end = 0;
  95 }
  96 #endif /* CONFIG_BLK_DEV_INITRD */
  97
  98 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
  99 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 100
 101 #ifndef __PAGETABLE_PMD_FOLDED
 102 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 103 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 104 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 105 #endif
 106
 107 asmlinkage void __init setup_vm(void)
 108 {
 109         extern char _start;
 110         uintptr_t i;
 111         uintptr_t pa = (uintptr_t) &_start;
 112         pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
 113
 114         va_pa_offset = PAGE_OFFSET - pa;
 115         pfn_base = PFN_DOWN(pa);
 116
 117         /* Sanity check alignment and size */
 118         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 119         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
 120
 121 #ifndef __PAGETABLE_PMD_FOLDED
 122         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 123                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 124                         __pgprot(_PAGE_TABLE));
 125         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
 126
 127         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 128                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 129                 swapper_pg_dir[o] =
 130                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 131                                 __pgprot(_PAGE_TABLE));
 132         }
 133         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 134                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
 135 #else
 136         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 137                 pfn_pgd(PFN_DOWN(pa), prot);
 138
 139         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 140                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 141                 swapper_pg_dir[o] =
 142                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 143         }
 144 #endif
 145 }
 146
 147 void __init parse_dtb(unsigned int hartid, void *dtb)
 148 {
 149         early_init_dt_scan(__va(dtb));
 150 }
 151
 152 static void __init setup_bootmem(void)
 153 {
 154         struct memblock_region *reg;
 155         phys_addr_t mem_size = 0;
 156
 157         /* Find the memory region containing the kernel */
 158         for_each_memblock(memory, reg) {
 159                 phys_addr_t vmlinux_end = __pa(_end);
 160                 phys_addr_t end = reg->base + reg->size;
 161
 162                 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 163                         /*
 164                          * Reserve from the start of the region to the end of
 165                          * the kernel
 166                          */
 167                         memblock_reserve(reg->base, vmlinux_end - reg->base);
 168                         mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 169                 }
 170         }
 171         BUG_ON(mem_size == 0);
 172
 173         set_max_mapnr(PFN_DOWN(mem_size));
 174         max_low_pfn = pfn_base + PFN_DOWN(mem_size);
 175
 176 #ifdef CONFIG_BLK_DEV_INITRD
 177         setup_initrd();
 178 #endif /* CONFIG_BLK_DEV_INITRD */
 179
 180         early_init_fdt_reserve_self();
 181         early_init_fdt_scan_reserved_mem();
 182         memblock_allow_resize();
 183         memblock_dump_all();
 184
 185         for_each_memblock(memory, reg) {
 186                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
 187                 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
 188
 189                 memblock_set_node(PFN_PHYS(start_pfn),
 190                                   PFN_PHYS(end_pfn - start_pfn),
 191                                   &memblock.memory, 0);
 192         }
 193 }
 194
 195 void __init setup_arch(char **cmdline_p)
 196 {
 197         *cmdline_p = boot_command_line;
 198
 199         parse_early_param();
 200
 201         init_mm.start_code = (unsigned long) _stext;
 202         init_mm.end_code   = (unsigned long) _etext;
 203         init_mm.end_data   = (unsigned long) _edata;
 204         init_mm.brk        = (unsigned long) _end;
 205
 206         setup_bootmem();
 207         paging_init();
 208         unflatten_device_tree();
 209
 210 #ifdef CONFIG_SMP
 211         setup_smp();
 212 #endif
 213
 214 #ifdef CONFIG_DUMMY_CONSOLE
 215         conswitchp = &dummy_con;
 216 #endif
 217
 218         riscv_fill_hwcap();
 219 }
 220
 221 static int __init riscv_device_init(void)
 222 {
 223         return of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 224 }
 225 subsys_initcall_sync(riscv_device_init);