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/swiotlb.h>
  21 #include <linux/smp.h>
  22 #include <linux/efi.h>
  23 #include <linux/crash_dump.h>
  24
  25 #include <asm/cpu_ops.h>
  26 #include <asm/early_ioremap.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/setup.h>
  29 #include <asm/set_memory.h>
  30 #include <asm/sections.h>
  31 #include <asm/sbi.h>
  32 #include <asm/tlbflush.h>
  33 #include <asm/thread_info.h>
  34 #include <asm/kasan.h>
  35 #include <asm/efi.h>
  36
  37 #include "head.h"
  38
  39 #if defined(CONFIG_DUMMY_CONSOLE) || defined(CONFIG_EFI)
  40 struct screen_info screen_info __section(".data") = {
  41         .orig_video_lines       = 30,
  42         .orig_video_cols        = 80,
  43         .orig_video_mode        = 0,
  44         .orig_video_ega_bx      = 0,
  45         .orig_video_isVGA       = 1,
  46         .orig_video_points      = 8
  47 };
  48 #endif
  49
  50 /*
  51  * The lucky hart to first increment this variable will boot the other cores.
  52  * This is used before the kernel initializes the BSS so it can't be in the
  53  * BSS.
  54  */
  55 atomic_t hart_lottery __section(".sdata")
  56 #ifdef CONFIG_XIP_KERNEL
  57 = ATOMIC_INIT(0xC001BEEF)
  58 #endif
  59 ;
  60 unsigned long boot_cpu_hartid;
  61 static DEFINE_PER_CPU(struct cpu, cpu_devices);
  62
  63 /*
  64  * Place kernel memory regions on the resource tree so that
  65  * kexec-tools can retrieve them from /proc/iomem. While there
  66  * also add "System RAM" regions for compatibility with other
  67  * archs, and the rest of the known regions for completeness.
  68  */
  69 static struct resource kimage_res = { .name = "Kernel image", };
  70 static struct resource code_res = { .name = "Kernel code", };
  71 static struct resource data_res = { .name = "Kernel data", };
  72 static struct resource rodata_res = { .name = "Kernel rodata", };
  73 static struct resource bss_res = { .name = "Kernel bss", };
  74 #ifdef CONFIG_CRASH_DUMP
  75 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
  76 #endif
  77
  78 static int __init add_resource(struct resource *parent,
  79                                 struct resource *res)
  80 {
  81         int ret = 0;
  82
  83         ret = insert_resource(parent, res);
  84         if (ret < 0) {
  85                 pr_err("Failed to add a %s resource at %llx\n",
  86                         res->name, (unsigned long long) res->start);
  87                 return ret;
  88         }
  89
  90         return 1;
  91 }
  92
  93 static int __init add_kernel_resources(void)
  94 {
  95         int ret = 0;
  96
  97         /*
  98          * The memory region of the kernel image is continuous and
  99          * was reserved on setup_bootmem, register it here as a
 100          * resource, with the various segments of the image as
 101          * child nodes.
 102          */
 103
 104         code_res.start = __pa_symbol(_text);
 105         code_res.end = __pa_symbol(_etext) - 1;
 106         code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 107
 108         rodata_res.start = __pa_symbol(__start_rodata);
 109         rodata_res.end = __pa_symbol(__end_rodata) - 1;
 110         rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 111
 112         data_res.start = __pa_symbol(_data);
 113         data_res.end = __pa_symbol(_edata) - 1;
 114         data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 115
 116         bss_res.start = __pa_symbol(__bss_start);
 117         bss_res.end = __pa_symbol(__bss_stop) - 1;
 118         bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 119
 120         kimage_res.start = code_res.start;
 121         kimage_res.end = bss_res.end;
 122         kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 123
 124         ret = add_resource(&iomem_resource, &kimage_res);
 125         if (ret < 0)
 126                 return ret;
 127
 128         ret = add_resource(&kimage_res, &code_res);
 129         if (ret < 0)
 130                 return ret;
 131
 132         ret = add_resource(&kimage_res, &rodata_res);
 133         if (ret < 0)
 134                 return ret;
 135
 136         ret = add_resource(&kimage_res, &data_res);
 137         if (ret < 0)
 138                 return ret;
 139
 140         ret = add_resource(&kimage_res, &bss_res);
 141
 142         return ret;
 143 }
 144
 145 static void __init init_resources(void)
 146 {
 147         struct memblock_region *region = NULL;
 148         struct resource *res = NULL;
 149         struct resource *mem_res = NULL;
 150         size_t mem_res_sz = 0;
 151         int num_resources = 0, res_idx = 0;
 152         int ret = 0;
 153
 154         /* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
 155         num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
 156         res_idx = num_resources - 1;
 157
 158         mem_res_sz = num_resources * sizeof(*mem_res);
 159         mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
 160         if (!mem_res)
 161                 panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);
 162
 163         /*
 164          * Start by adding the reserved regions, if they overlap
 165          * with /memory regions, insert_resource later on will take
 166          * care of it.
 167          */
 168         ret = add_kernel_resources();
 169         if (ret < 0)
 170                 goto error;
 171
 172 #ifdef CONFIG_KEXEC_CORE
 173         if (crashk_res.start != crashk_res.end) {
 174                 ret = add_resource(&iomem_resource, &crashk_res);
 175                 if (ret < 0)
 176                         goto error;
 177         }
 178 #endif
 179
 180 #ifdef CONFIG_CRASH_DUMP
 181         if (elfcorehdr_size > 0) {
 182                 elfcorehdr_res.start = elfcorehdr_addr;
 183                 elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
 184                 elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 185                 add_resource(&iomem_resource, &elfcorehdr_res);
 186         }
 187 #endif
 188
 189         for_each_reserved_mem_region(region) {
 190                 res = &mem_res[res_idx--];
 191
 192                 res->name = "Reserved";
 193                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 194                 res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
 195                 res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
 196
 197                 /*
 198                  * Ignore any other reserved regions within
 199                  * system memory.
 200                  */
 201                 if (memblock_is_memory(res->start)) {
 202                         /* Re-use this pre-allocated resource */
 203                         res_idx++;
 204                         continue;
 205                 }
 206
 207                 ret = add_resource(&iomem_resource, res);
 208                 if (ret < 0)
 209                         goto error;
 210         }
 211
 212         /* Add /memory regions to the resource tree */
 213         for_each_mem_region(region) {
 214                 res = &mem_res[res_idx--];
 215
 216                 if (unlikely(memblock_is_nomap(region))) {
 217                         res->name = "Reserved";
 218                         res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 219                 } else {
 220                         res->name = "System RAM";
 221                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 222                 }
 223
 224                 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
 225                 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
 226
 227                 ret = add_resource(&iomem_resource, res);
 228                 if (ret < 0)
 229                         goto error;
 230         }
 231
 232         /* Clean-up any unused pre-allocated resources */
 233         mem_res_sz = (num_resources - res_idx + 1) * sizeof(*mem_res);
 234         memblock_free((phys_addr_t) mem_res, mem_res_sz);
 235         return;
 236
 237  error:
 238         /* Better an empty resource tree than an inconsistent one */
 239         release_child_resources(&iomem_resource);
 240         memblock_free((phys_addr_t) mem_res, mem_res_sz);
 241 }
 242
 243
 244 static void __init parse_dtb(void)
 245 {
 246         /* Early scan of device tree from init memory */
 247         if (early_init_dt_scan(dtb_early_va)) {
 248                 const char *name = of_flat_dt_get_machine_name();
 249
 250                 if (name) {
 251                         pr_info("Machine model: %s\n", name);
 252                         dump_stack_set_arch_desc("%s (DT)", name);
 253                 }
 254                 return;
 255         }
 256
 257         pr_err("No DTB passed to the kernel\n");
 258 #ifdef CONFIG_CMDLINE_FORCE
 259         strlcpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 260         pr_info("Forcing kernel command line to: %s\n", boot_command_line);
 261 #endif
 262 }
 263
 264 void __init setup_arch(char **cmdline_p)
 265 {
 266         parse_dtb();
 267         init_mm.start_code = (unsigned long) _stext;
 268         init_mm.end_code   = (unsigned long) _etext;
 269         init_mm.end_data   = (unsigned long) _edata;
 270         init_mm.brk        = (unsigned long) _end;
 271
 272         *cmdline_p = boot_command_line;
 273
 274         early_ioremap_setup();
 275         jump_label_init();
 276         parse_early_param();
 277
 278         efi_init();
 279         setup_bootmem();
 280         paging_init();
 281 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
 282         unflatten_and_copy_device_tree();
 283 #else
 284         if (early_init_dt_verify(__va(XIP_FIXUP(dtb_early_pa))))
 285                 unflatten_device_tree();
 286         else
 287                 pr_err("No DTB found in kernel mappings\n");
 288 #endif
 289         misc_mem_init();
 290
 291         init_resources();
 292         sbi_init();
 293
 294         if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
 295                 protect_kernel_text_data();
 296                 protect_kernel_linear_mapping_text_rodata();
 297         }
 298
 299 #ifdef CONFIG_SWIOTLB
 300         swiotlb_init(1);
 301 #endif
 302
 303 #ifdef CONFIG_KASAN
 304         kasan_init();
 305 #endif
 306
 307 #ifdef CONFIG_SMP
 308         setup_smp();
 309 #endif
 310
 311         riscv_fill_hwcap();
 312 }
 313
 314 static int __init topology_init(void)
 315 {
 316         int i, ret;
 317
 318         for_each_online_node(i)
 319                 register_one_node(i);
 320
 321         for_each_possible_cpu(i) {
 322                 struct cpu *cpu = &per_cpu(cpu_devices, i);
 323
 324                 cpu->hotpluggable = cpu_has_hotplug(i);
 325                 ret = register_cpu(cpu, i);
 326                 if (unlikely(ret))
 327                         pr_warn("Warning: %s: register_cpu %d failed (%d)\n",
 328                                __func__, i, ret);
 329         }
 330
 331         return 0;
 332 }
 333 subsys_initcall(topology_init);
 334
 335 void free_initmem(void)
 336 {
 337         unsigned long init_begin = (unsigned long)__init_begin;
 338         unsigned long init_end = (unsigned long)__init_end;
 339
 340         if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
 341                 set_memory_rw_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
 342
 343         free_initmem_default(POISON_FREE_INITMEM);
 344 }