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