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/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 unsigned long boot_cpu_hartid;
  63
  64 unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
  65         [0 ... NR_CPUS-1] = INVALID_HARTID
  66 };
  67
  68 void __init smp_setup_processor_id(void)
  69 {
  70         cpuid_to_hartid_map(0) = boot_cpu_hartid;
  71 }
  72
  73 #ifdef CONFIG_BLK_DEV_INITRD
  74 static void __init setup_initrd(void)
  75 {
  76         unsigned long size;
  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 parse_dtb(unsigned int hartid, void *dtb)
 151 {
 152         if (!early_init_dt_scan(__va(dtb)))
 153                 return;
 154
 155         pr_err("No DTB passed to the kernel\n");
 156 #ifdef CONFIG_CMDLINE_FORCE
 157         strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 158         pr_info("Forcing kernel command line to: %s\n", boot_command_line);
 159 #endif
 160 }
 161
 162 static void __init setup_bootmem(void)
 163 {
 164         struct memblock_region *reg;
 165         phys_addr_t mem_size = 0;
 166
 167         /* Find the memory region containing the kernel */
 168         for_each_memblock(memory, reg) {
 169                 phys_addr_t vmlinux_end = __pa(_end);
 170                 phys_addr_t end = reg->base + reg->size;
 171
 172                 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 173                         /*
 174                          * Reserve from the start of the region to the end of
 175                          * the kernel
 176                          */
 177                         memblock_reserve(reg->base, vmlinux_end - reg->base);
 178                         mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 179                 }
 180         }
 181         BUG_ON(mem_size == 0);
 182
 183         set_max_mapnr(PFN_DOWN(mem_size));
 184         max_low_pfn = memblock_end_of_DRAM();
 185
 186 #ifdef CONFIG_BLK_DEV_INITRD
 187         setup_initrd();
 188 #endif /* CONFIG_BLK_DEV_INITRD */
 189
 190         early_init_fdt_reserve_self();
 191         early_init_fdt_scan_reserved_mem();
 192         memblock_allow_resize();
 193         memblock_dump_all();
 194
 195         for_each_memblock(memory, reg) {
 196                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
 197                 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
 198
 199                 memblock_set_node(PFN_PHYS(start_pfn),
 200                                   PFN_PHYS(end_pfn - start_pfn),
 201                                   &memblock.memory, 0);
 202         }
 203 }
 204
 205 void __init setup_arch(char **cmdline_p)
 206 {
 207         *cmdline_p = boot_command_line;
 208
 209         parse_early_param();
 210
 211         init_mm.start_code = (unsigned long) _stext;
 212         init_mm.end_code   = (unsigned long) _etext;
 213         init_mm.end_data   = (unsigned long) _edata;
 214         init_mm.brk        = (unsigned long) _end;
 215
 216         setup_bootmem();
 217         paging_init();
 218         unflatten_device_tree();
 219
 220 #ifdef CONFIG_SWIOTLB
 221         swiotlb_init(1);
 222 #endif
 223
 224 #ifdef CONFIG_SMP
 225         setup_smp();
 226 #endif
 227
 228 #ifdef CONFIG_DUMMY_CONSOLE
 229         conswitchp = &dummy_con;
 230 #endif
 231
 232         riscv_fill_hwcap();
 233 }
 234