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