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_EARLY_PRINTK
  43 static void sbi_console_write(struct console *co, const char *buf,
  44                               unsigned int n)
  45 {
  46         int i;
  47
  48         for (i = 0; i < n; ++i) {
  49                 if (buf[i] == '\n')
  50                         sbi_console_putchar('\r');
  51                 sbi_console_putchar(buf[i]);
  52         }
  53 }
  54
  55 struct console riscv_sbi_early_console_dev __initdata = {
  56         .name   = "early",
  57         .write  = sbi_console_write,
  58         .flags  = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
  59         .index  = -1
  60 };
  61 #endif
  62
  63 #ifdef CONFIG_DUMMY_CONSOLE
  64 struct screen_info screen_info = {
  65         .orig_video_lines       = 30,
  66         .orig_video_cols        = 80,
  67         .orig_video_mode        = 0,
  68         .orig_video_ega_bx      = 0,
  69         .orig_video_isVGA       = 1,
  70         .orig_video_points      = 8
  71 };
  72 #endif
  73
  74 unsigned long va_pa_offset;
  75 EXPORT_SYMBOL(va_pa_offset);
  76 unsigned long pfn_base;
  77 EXPORT_SYMBOL(pfn_base);
  78
  79 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  80 EXPORT_SYMBOL(empty_zero_page);
  81
  82 /* The lucky hart to first increment this variable will boot the other cores */
  83 atomic_t hart_lottery;
  84 unsigned long boot_cpu_hartid;
  85
  86 unsigned long __cpuid_to_hartid_map[NR_CPUS] = {
  87         [0 ... NR_CPUS-1] = INVALID_HARTID
  88 };
  89
  90 void __init smp_setup_processor_id(void)
  91 {
  92         cpuid_to_hartid_map(0) = boot_cpu_hartid;
  93 }
  94
  95 #ifdef CONFIG_BLK_DEV_INITRD
  96 static void __init setup_initrd(void)
  97 {
  98         unsigned long size;
  99
 100         if (initrd_start >= initrd_end) {
 101                 printk(KERN_INFO "initrd not found or empty");
 102                 goto disable;
 103         }
 104         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
 105                 printk(KERN_ERR "initrd extends beyond end of memory");
 106                 goto disable;
 107         }
 108
 109         size =  initrd_end - initrd_start;
 110         memblock_reserve(__pa(initrd_start), size);
 111         initrd_below_start_ok = 1;
 112
 113         printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
 114                 (void *)(initrd_start), size);
 115         return;
 116 disable:
 117         pr_cont(" - disabling initrd\n");
 118         initrd_start = 0;
 119         initrd_end = 0;
 120 }
 121 #endif /* CONFIG_BLK_DEV_INITRD */
 122
 123 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 124 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 125
 126 #ifndef __PAGETABLE_PMD_FOLDED
 127 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 128 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 129 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 130 #endif
 131
 132 asmlinkage void __init setup_vm(void)
 133 {
 134         extern char _start;
 135         uintptr_t i;
 136         uintptr_t pa = (uintptr_t) &_start;
 137         pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
 138
 139         va_pa_offset = PAGE_OFFSET - pa;
 140         pfn_base = PFN_DOWN(pa);
 141
 142         /* Sanity check alignment and size */
 143         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 144         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
 145
 146 #ifndef __PAGETABLE_PMD_FOLDED
 147         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 148                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 149                         __pgprot(_PAGE_TABLE));
 150         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
 151
 152         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 153                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 154                 swapper_pg_dir[o] =
 155                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 156                                 __pgprot(_PAGE_TABLE));
 157         }
 158         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 159                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
 160 #else
 161         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 162                 pfn_pgd(PFN_DOWN(pa), prot);
 163
 164         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 165                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 166                 swapper_pg_dir[o] =
 167                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 168         }
 169 #endif
 170 }
 171
 172 void __init parse_dtb(unsigned int hartid, void *dtb)
 173 {
 174         early_init_dt_scan(__va(dtb));
 175 }
 176
 177 static void __init setup_bootmem(void)
 178 {
 179         struct memblock_region *reg;
 180         phys_addr_t mem_size = 0;
 181
 182         /* Find the memory region containing the kernel */
 183         for_each_memblock(memory, reg) {
 184                 phys_addr_t vmlinux_end = __pa(_end);
 185                 phys_addr_t end = reg->base + reg->size;
 186
 187                 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 188                         /*
 189                          * Reserve from the start of the region to the end of
 190                          * the kernel
 191                          */
 192                         memblock_reserve(reg->base, vmlinux_end - reg->base);
 193                         mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 194                 }
 195         }
 196         BUG_ON(mem_size == 0);
 197
 198         set_max_mapnr(PFN_DOWN(mem_size));
 199         max_low_pfn = memblock_end_of_DRAM();
 200
 201 #ifdef CONFIG_BLK_DEV_INITRD
 202         setup_initrd();
 203 #endif /* CONFIG_BLK_DEV_INITRD */
 204
 205         early_init_fdt_reserve_self();
 206         early_init_fdt_scan_reserved_mem();
 207         memblock_allow_resize();
 208         memblock_dump_all();
 209
 210         for_each_memblock(memory, reg) {
 211                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
 212                 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
 213
 214                 memblock_set_node(PFN_PHYS(start_pfn),
 215                                   PFN_PHYS(end_pfn - start_pfn),
 216                                   &memblock.memory, 0);
 217         }
 218 }
 219
 220 void __init setup_arch(char **cmdline_p)
 221 {
 222 #if defined(CONFIG_EARLY_PRINTK)
 223        if (likely(early_console == NULL)) {
 224                early_console = &riscv_sbi_early_console_dev;
 225                register_console(early_console);
 226        }
 227 #endif
 228         *cmdline_p = boot_command_line;
 229
 230         parse_early_param();
 231
 232         init_mm.start_code = (unsigned long) _stext;
 233         init_mm.end_code   = (unsigned long) _etext;
 234         init_mm.end_data   = (unsigned long) _edata;
 235         init_mm.brk        = (unsigned long) _end;
 236
 237         setup_bootmem();
 238         paging_init();
 239         unflatten_device_tree();
 240
 241 #ifdef CONFIG_SWIOTLB
 242         swiotlb_init(1);
 243 #endif
 244
 245 #ifdef CONFIG_SMP
 246         setup_smp();
 247 #endif
 248
 249 #ifdef CONFIG_DUMMY_CONSOLE
 250         conswitchp = &dummy_con;
 251 #endif
 252
 253         riscv_fill_hwcap();
 254 }
 255