arch/riscv/kernel/setup.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
   4  *  Chen Liqin <liqin.chen@sunplusct.com>
   5  *  Lennox Wu <lennox.wu@sunplusct.com>
   6  * Copyright (C) 2012 Regents of the University of California
   7  * Copyright (C) 2020 FORTH-ICS/CARV
   8  *  Nick Kossifidis <mick@ics.forth.gr>
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/mm.h>
  13 #include <linux/memblock.h>
  14 #include <linux/sched.h>
  15 #include <linux/console.h>
  16 #include <linux/screen_info.h>
  17 #include <linux/of_fdt.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/sched/task.h>
  20 #include <linux/smp.h>
  21 #include <linux/efi.h>
  22 #include <linux/crash_dump.h>
  23
  24 #include <asm/alternative.h>
  25 #include <asm/cacheflush.h>
  26 #include <asm/cpu_ops.h>
  27 #include <asm/early_ioremap.h>
  28 #include <asm/pgtable.h>
  29 #include <asm/setup.h>
  30 #include <asm/set_memory.h>
  31 #include <asm/sections.h>
  32 #include <asm/sbi.h>
  33 #include <asm/tlbflush.h>
  34 #include <asm/thread_info.h>
  35 #include <asm/kasan.h>
  36 #include <asm/efi.h>
  37
  38 #include "head.h"
  39
  40 #if defined(CONFIG_DUMMY_CONSOLE) || defined(CONFIG_EFI)
  41 struct screen_info screen_info __section(".data") = {
  42         .orig_video_lines       = 30,
  43         .orig_video_cols        = 80,
  44         .orig_video_mode        = 0,
  45         .orig_video_ega_bx      = 0,
  46         .orig_video_isVGA       = 1,
  47         .orig_video_points      = 8
  48 };
  49 #endif
  50
  51 /*
  52  * The lucky hart to first increment this variable will boot the other cores.
  53  * This is used before the kernel initializes the BSS so it can't be in the
  54  * BSS.
  55  */
  56 atomic_t hart_lottery __section(".sdata")
  57 #ifdef CONFIG_XIP_KERNEL
  58 = ATOMIC_INIT(0xC001BEEF)
  59 #endif
  60 ;
  61 unsigned long boot_cpu_hartid;
  62 static DEFINE_PER_CPU(struct cpu, cpu_devices);
  63
  64 /*
  65  * Place kernel memory regions on the resource tree so that
  66  * kexec-tools can retrieve them from /proc/iomem. While there
  67  * also add "System RAM" regions for compatibility with other
  68  * archs, and the rest of the known regions for completeness.
  69  */
  70 static struct resource kimage_res = { .name = "Kernel image", };
  71 static struct resource code_res = { .name = "Kernel code", };
  72 static struct resource data_res = { .name = "Kernel data", };
  73 static struct resource rodata_res = { .name = "Kernel rodata", };
  74 static struct resource bss_res = { .name = "Kernel bss", };
  75 #ifdef CONFIG_CRASH_DUMP
  76 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
  77 #endif
  78
  79 static int __init add_resource(struct resource *parent,
  80                                 struct resource *res)
  81 {
  82         int ret = 0;
  83
  84         ret = insert_resource(parent, res);
  85         if (ret < 0) {
  86                 pr_err("Failed to add a %s resource at %llx\n",
  87                         res->name, (unsigned long long) res->start);
  88                 return ret;
  89         }
  90
  91         return 1;
  92 }
  93
  94 static int __init add_kernel_resources(void)
  95 {
  96         int ret = 0;
  97
  98         /*
  99          * The memory region of the kernel image is continuous and
 100          * was reserved on setup_bootmem, register it here as a
 101          * resource, with the various segments of the image as
 102          * child nodes.
 103          */
 104
 105         code_res.start = __pa_symbol(_text);
 106         code_res.end = __pa_symbol(_etext) - 1;
 107         code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 108
 109         rodata_res.start = __pa_symbol(__start_rodata);
 110         rodata_res.end = __pa_symbol(__end_rodata) - 1;
 111         rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 112
 113         data_res.start = __pa_symbol(_data);
 114         data_res.end = __pa_symbol(_edata) - 1;
 115         data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 116
 117         bss_res.start = __pa_symbol(__bss_start);
 118         bss_res.end = __pa_symbol(__bss_stop) - 1;
 119         bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 120
 121         kimage_res.start = code_res.start;
 122         kimage_res.end = bss_res.end;
 123         kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 124
 125         ret = add_resource(&iomem_resource, &kimage_res);
 126         if (ret < 0)
 127                 return ret;
 128
 129         ret = add_resource(&kimage_res, &code_res);
 130         if (ret < 0)
 131                 return ret;
 132
 133         ret = add_resource(&kimage_res, &rodata_res);
 134         if (ret < 0)
 135                 return ret;
 136
 137         ret = add_resource(&kimage_res, &data_res);
 138         if (ret < 0)
 139                 return ret;
 140
 141         ret = add_resource(&kimage_res, &bss_res);
 142
 143         return ret;
 144 }
 145
 146 static void __init init_resources(void)
 147 {
 148         struct memblock_region *region = NULL;
 149         struct resource *res = NULL;
 150         struct resource *mem_res = NULL;
 151         size_t mem_res_sz = 0;
 152         int num_resources = 0, res_idx = 0;
 153         int ret = 0;
 154
 155         /* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
 156         num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
 157         res_idx = num_resources - 1;
 158
 159         mem_res_sz = num_resources * sizeof(*mem_res);
 160         mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
 161         if (!mem_res)
 162                 panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);
 163
 164         /*
 165          * Start by adding the reserved regions, if they overlap
 166          * with /memory regions, insert_resource later on will take
 167          * care of it.
 168          */
 169         ret = add_kernel_resources();
 170         if (ret < 0)
 171                 goto error;
 172
 173 #ifdef CONFIG_KEXEC_CORE
 174         if (crashk_res.start != crashk_res.end) {
 175                 ret = add_resource(&iomem_resource, &crashk_res);
 176                 if (ret < 0)
 177                         goto error;
 178         }
 179 #endif
 180
 181 #ifdef CONFIG_CRASH_DUMP
 182         if (elfcorehdr_size > 0) {
 183                 elfcorehdr_res.start = elfcorehdr_addr;
 184                 elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
 185                 elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 186                 add_resource(&iomem_resource, &elfcorehdr_res);
 187         }
 188 #endif
 189
 190         for_each_reserved_mem_region(region) {
 191                 res = &mem_res[res_idx--];
 192
 193                 res->name = "Reserved";
 194                 res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
 195                 res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
 196                 res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
 197
 198                 /*
 199                  * Ignore any other reserved regions within
 200                  * system memory.
 201                  */
 202                 if (memblock_is_memory(res->start)) {
 203                         /* Re-use this pre-allocated resource */
 204                         res_idx++;
 205                         continue;
 206                 }
 207
 208                 ret = add_resource(&iomem_resource, res);
 209                 if (ret < 0)
 210                         goto error;
 211         }
 212
 213         /* Add /memory regions to the resource tree */
 214         for_each_mem_region(region) {
 215                 res = &mem_res[res_idx--];
 216
 217                 if (unlikely(memblock_is_nomap(region))) {
 218                         res->name = "Reserved";
 219                         res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
 220                 } else {
 221                         res->name = "System RAM";
 222                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 223                 }
 224
 225                 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
 226                 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
 227
 228                 ret = add_resource(&iomem_resource, res);
 229                 if (ret < 0)
 230                         goto error;
 231         }
 232
 233         /* Clean-up any unused pre-allocated resources */
 234         if (res_idx >= 0)
 235                 memblock_free(mem_res, (res_idx + 1) * sizeof(*mem_res));
 236         return;
 237
 238  error:
 239         /* Better an empty resource tree than an inconsistent one */
 240         release_child_resources(&iomem_resource);
 241         memblock_free(mem_res, mem_res_sz);
 242 }
 243
 244
 245 static void __init parse_dtb(void)
 246 {
 247         /* Early scan of device tree from init memory */
 248         if (early_init_dt_scan(dtb_early_va)) {
 249                 const char *name = of_flat_dt_get_machine_name();
 250
 251                 if (name) {
 252                         pr_info("Machine model: %s\n", name);
 253                         dump_stack_set_arch_desc("%s (DT)", name);
 254                 }
 255         } else {
 256                 pr_err("No DTB passed to the kernel\n");
 257         }
 258
 259 #ifdef CONFIG_CMDLINE_FORCE
 260         strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 261         pr_info("Forcing kernel command line to: %s\n", boot_command_line);
 262 #endif
 263 }
 264
 265 void __init setup_arch(char **cmdline_p)
 266 {
 267         parse_dtb();
 268         setup_initial_init_mm(_stext, _etext, _edata, _end);
 269
 270         *cmdline_p = boot_command_line;
 271
 272         early_ioremap_setup();
 273         jump_label_init();
 274         parse_early_param();
 275
 276         efi_init();
 277         paging_init();
 278 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
 279         unflatten_and_copy_device_tree();
 280 #else
 281         if (early_init_dt_verify(__va(XIP_FIXUP(dtb_early_pa))))
 282                 unflatten_device_tree();
 283         else
 284                 pr_err("No DTB found in kernel mappings\n");
 285 #endif
 286         early_init_fdt_scan_reserved_mem();
 287         misc_mem_init();
 288
 289         init_resources();
 290         sbi_init();
 291
 292 #ifdef CONFIG_KASAN
 293         kasan_init();
 294 #endif
 295
 296 #ifdef CONFIG_SMP
 297         setup_smp();
 298 #endif
 299
 300         riscv_init_cbom_blocksize();
 301         riscv_fill_hwcap();
 302         apply_boot_alternatives();
 303         if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
 304             riscv_isa_extension_available(NULL, ZICBOM))
 305                 riscv_noncoherent_supported();
 306 }
 307
 308 static int __init topology_init(void)
 309 {
 310         int i, ret;
 311
 312         for_each_possible_cpu(i) {
 313                 struct cpu *cpu = &per_cpu(cpu_devices, i);
 314
 315                 cpu->hotpluggable = cpu_has_hotplug(i);
 316                 ret = register_cpu(cpu, i);
 317                 if (unlikely(ret))
 318                         pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
 319                                __func__, i, ret);
 320         }
 321
 322         return 0;
 323 }
 324 subsys_initcall(topology_init);
 325
 326 void free_initmem(void)
 327 {
 328         if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
 329                 set_kernel_memory(lm_alias(__init_begin), lm_alias(__init_end), set_memory_rw_nx);
 330                 if (IS_ENABLED(CONFIG_64BIT))
 331                         set_kernel_memory(__init_begin, __init_end, set_memory_nx);
 332         }
 333
 334         free_initmem_default(POISON_FREE_INITMEM);
 335 }