xref: /linux/arch/riscv/kernel/setup.c (revision d639d9fa162aadec1ae9980c4dcf6e50bd2f8290) 
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/acpi.h>
12 #include <linux/cpu.h>
13 #include <linux/init.h>
14 #include <linux/mm.h>
15 #include <linux/memblock.h>
16 #include <linux/sched.h>
17 #include <linux/console.h>
18 #include <linux/of_fdt.h>
19 #include <linux/sched/task.h>
20 #include <linux/smp.h>
21 #include <linux/efi.h>
22 #include <linux/crash_dump.h>
23 #include <linux/panic_notifier.h>
24 #include <linux/jump_label.h>
25 #include <linux/gcd.h>
26 
27 #include <asm/acpi.h>
28 #include <asm/alternative.h>
29 #include <asm/cacheflush.h>
30 #include <asm/cpufeature.h>
31 #include <asm/early_ioremap.h>
32 #include <asm/pgtable.h>
33 #include <asm/setup.h>
34 #include <asm/set_memory.h>
35 #include <asm/sections.h>
36 #include <asm/sbi.h>
37 #include <asm/tlbflush.h>
38 #include <asm/thread_info.h>
39 #include <asm/kasan.h>
40 #include <asm/efi.h>
41 
42 #include "head.h"
43 
44 /*
45  * The lucky hart to first increment this variable will boot the other cores.
46  * This is used before the kernel initializes the BSS so it can't be in the
47  * BSS.
48  */
49 atomic_t hart_lottery __section(".sdata");
50 unsigned long boot_cpu_hartid;
51 EXPORT_SYMBOL_GPL(boot_cpu_hartid);
52 
53 /*
54  * Place kernel memory regions on the resource tree so that
55  * kexec-tools can retrieve them from /proc/iomem. While there
56  * also add "System RAM" regions for compatibility with other
57  * archs, and the rest of the known regions for completeness.
58  */
59 static struct resource kimage_res = { .name = "Kernel image", };
60 static struct resource code_res = { .name = "Kernel code", };
61 static struct resource data_res = { .name = "Kernel data", };
62 static struct resource rodata_res = { .name = "Kernel rodata", };
63 static struct resource bss_res = { .name = "Kernel bss", };
64 #ifdef CONFIG_CRASH_DUMP
65 static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
66 #endif
67 
68 static int num_standard_resources;
69 static struct resource *standard_resources;
70 
71 static int __init add_resource(struct resource *parent,
72 				struct resource *res)
73 {
74 	int ret;
75 
76 	ret = insert_resource(parent, res);
77 	if (ret < 0)
78 		pr_err("Failed to add resource %s %pR\n", res->name, res);
79 
80 	return ret;
81 }
82 
83 static int __init add_kernel_resources(void)
84 {
85 	int ret = 0;
86 
87 	/*
88 	 * The memory region of the kernel image is continuous and
89 	 * was reserved on setup_bootmem, register it here as a
90 	 * resource, with the various segments of the image as
91 	 * child nodes.
92 	 */
93 
94 	code_res.start = __pa_symbol(_text);
95 	code_res.end = __pa_symbol(_etext) - 1;
96 	code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
97 
98 	rodata_res.start = __pa_symbol(__start_rodata);
99 	rodata_res.end = __pa_symbol(__end_rodata) - 1;
100 	rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
101 
102 	data_res.start = __pa_symbol(_data);
103 	data_res.end = __pa_symbol(_edata) - 1;
104 	data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
105 
106 	bss_res.start = __pa_symbol(__bss_start);
107 	bss_res.end = __pa_symbol(__bss_stop) - 1;
108 	bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
109 
110 	kimage_res.start = code_res.start;
111 	kimage_res.end = bss_res.end;
112 	kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
113 
114 	ret = add_resource(&iomem_resource, &kimage_res);
115 	if (ret < 0)
116 		return ret;
117 
118 	ret = add_resource(&kimage_res, &code_res);
119 	if (ret < 0)
120 		return ret;
121 
122 	ret = add_resource(&kimage_res, &rodata_res);
123 	if (ret < 0)
124 		return ret;
125 
126 	ret = add_resource(&kimage_res, &data_res);
127 	if (ret < 0)
128 		return ret;
129 
130 	ret = add_resource(&kimage_res, &bss_res);
131 
132 	return ret;
133 }
134 
135 static void __init init_resources(void)
136 {
137 	struct memblock_region *region = NULL;
138 	struct resource *res = NULL;
139 	struct resource *mem_res = NULL;
140 	size_t mem_res_sz = 0;
141 	int num_resources = 0, res_idx = 0, non_resv_res = 0;
142 	int ret = 0;
143 
144 	/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
145 	num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
146 	res_idx = num_resources - 1;
147 
148 	mem_res_sz = num_resources * sizeof(*mem_res);
149 	mem_res = memblock_alloc_or_panic(mem_res_sz, SMP_CACHE_BYTES);
150 
151 	/*
152 	 * Start by adding the reserved regions, if they overlap
153 	 * with /memory regions, insert_resource later on will take
154 	 * care of it.
155 	 */
156 	ret = add_kernel_resources();
157 	if (ret < 0)
158 		goto error;
159 
160 #ifdef CONFIG_CRASH_DUMP
161 	if (elfcorehdr_size > 0) {
162 		elfcorehdr_res.start = elfcorehdr_addr;
163 		elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
164 		elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
165 		add_resource(&iomem_resource, &elfcorehdr_res);
166 	}
167 #endif
168 
169 	for_each_reserved_mem_region(region) {
170 		res = &mem_res[res_idx--];
171 
172 		res->name = "Reserved";
173 		res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
174 		res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
175 		res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
176 
177 		/*
178 		 * Ignore any other reserved regions within
179 		 * system memory.
180 		 */
181 		if (memblock_is_memory(res->start)) {
182 			/* Re-use this pre-allocated resource */
183 			res_idx++;
184 			continue;
185 		}
186 
187 		ret = add_resource(&iomem_resource, res);
188 		if (ret < 0)
189 			goto error;
190 	}
191 
192 	/* Add /memory regions to the resource tree */
193 	for_each_mem_region(region) {
194 		res = &mem_res[res_idx--];
195 		non_resv_res++;
196 
197 		if (unlikely(memblock_is_nomap(region))) {
198 			res->name = "Reserved";
199 			res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
200 		} else {
201 			res->name = "System RAM";
202 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
203 		}
204 
205 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
206 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
207 
208 		ret = add_resource(&iomem_resource, res);
209 		if (ret < 0)
210 			goto error;
211 	}
212 
213 	num_standard_resources = non_resv_res;
214 	standard_resources = &mem_res[res_idx + 1];
215 
216 	/* Clean-up any unused pre-allocated resources */
217 	if (res_idx >= 0)
218 		memblock_free(mem_res, (res_idx + 1) * sizeof(*mem_res));
219 	return;
220 
221  error:
222 	/* Better an empty resource tree than an inconsistent one */
223 	release_child_resources(&iomem_resource);
224 	memblock_free(mem_res, mem_res_sz);
225 }
226 
227 static int __init reserve_memblock_reserved_regions(void)
228 {
229 	u64 i, j;
230 
231 	for (i = 0; i < num_standard_resources; i++) {
232 		struct resource *mem = &standard_resources[i];
233 		phys_addr_t r_start, r_end, mem_size = resource_size(mem);
234 
235 		if (!memblock_is_region_reserved(mem->start, mem_size))
236 			continue;
237 
238 		for_each_reserved_mem_range(j, &r_start, &r_end) {
239 			resource_size_t start, end;
240 
241 			start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
242 			end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
243 
244 			if (start > mem->end || end < mem->start)
245 				continue;
246 
247 			reserve_region_with_split(mem, start, end, "Reserved");
248 		}
249 	}
250 
251 	return 0;
252 }
253 arch_initcall(reserve_memblock_reserved_regions);
254 
255 static void __init parse_dtb(void)
256 {
257 	/* Early scan of device tree from init memory */
258 	if (early_init_dt_scan(dtb_early_va, dtb_early_pa)) {
259 		const char *name = of_flat_dt_get_machine_name();
260 
261 		if (name) {
262 			pr_info("Machine model: %s\n", name);
263 			dump_stack_set_arch_desc("%s (DT)", name);
264 		}
265 	} else {
266 		pr_err("No DTB passed to the kernel\n");
267 	}
268 }
269 
270 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
271 DEFINE_STATIC_KEY_TRUE(qspinlock_key);
272 EXPORT_SYMBOL(qspinlock_key);
273 #endif
274 
275 static void __init riscv_spinlock_init(void)
276 {
277 	char *using_ext = NULL;
278 
279 	if (IS_ENABLED(CONFIG_RISCV_TICKET_SPINLOCKS)) {
280 		pr_info("Ticket spinlock: enabled\n");
281 		return;
282 	}
283 
284 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
285 	    IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) &&
286 	    IS_ENABLED(CONFIG_TOOLCHAIN_HAS_ZACAS) &&
287 	    riscv_isa_extension_available(NULL, ZABHA) &&
288 	    riscv_isa_extension_available(NULL, ZACAS)) {
289 		using_ext = "using Zabha";
290 	} else if (riscv_isa_extension_available(NULL, ZICCRSE)) {
291 		using_ext = "using Ziccrse";
292 	}
293 #if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
294 	else {
295 		static_branch_disable(&qspinlock_key);
296 		pr_info("Ticket spinlock: enabled\n");
297 		return;
298 	}
299 #endif
300 
301 	if (!using_ext)
302 		pr_err("Queued spinlock without Zabha or Ziccrse");
303 	else
304 		pr_info("Queued spinlock %s: enabled\n", using_ext);
305 }
306 
307 extern void __init init_rt_signal_env(void);
308 
309 void __init setup_arch(char **cmdline_p)
310 {
311 	parse_dtb();
312 	setup_initial_init_mm(_stext, _etext, _edata, _end);
313 
314 	*cmdline_p = boot_command_line;
315 
316 	early_ioremap_setup();
317 	sbi_init();
318 	jump_label_init();
319 	parse_early_param();
320 
321 	efi_init();
322 	paging_init();
323 
324 	/* Parse the ACPI tables for possible boot-time configuration */
325 	acpi_boot_table_init();
326 
327 	if (acpi_disabled) {
328 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
329 		unflatten_and_copy_device_tree();
330 #else
331 		unflatten_device_tree();
332 #endif
333 	}
334 
335 	misc_mem_init();
336 
337 	init_resources();
338 
339 #ifdef CONFIG_KASAN
340 	kasan_init();
341 #endif
342 
343 #ifdef CONFIG_SMP
344 	setup_smp();
345 #endif
346 
347 	if (!acpi_disabled) {
348 		acpi_init_rintc_map();
349 		acpi_map_cpus_to_nodes();
350 	}
351 
352 	riscv_init_cbo_blocksizes();
353 	riscv_fill_hwcap();
354 	apply_boot_alternatives();
355 	init_rt_signal_env();
356 
357 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
358 	    riscv_isa_extension_available(NULL, ZICBOM))
359 		riscv_noncoherent_supported();
360 	riscv_set_dma_cache_alignment();
361 
362 	riscv_user_isa_enable();
363 	riscv_spinlock_init();
364 
365 	if (!IS_ENABLED(CONFIG_RISCV_ISA_ZBB) || !riscv_isa_extension_available(NULL, ZBB))
366 		static_branch_disable(&efficient_ffs_key);
367 }
368 
369 bool arch_cpu_is_hotpluggable(int cpu)
370 {
371 	return cpu_has_hotplug(cpu);
372 }
373 
374 void free_initmem(void)
375 {
376 	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
377 		set_kernel_memory(lm_alias(__init_begin), lm_alias(__init_end), set_memory_rw_nx);
378 		if (IS_ENABLED(CONFIG_64BIT))
379 			set_kernel_memory(__init_begin, __init_end, set_memory_nx);
380 	}
381 
382 	free_initmem_default(POISON_FREE_INITMEM);
383 }
384 
385 static int dump_kernel_offset(struct notifier_block *self,
386 			      unsigned long v, void *p)
387 {
388 	pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
389 		 kernel_map.virt_offset,
390 		 KERNEL_LINK_ADDR);
391 
392 	return 0;
393 }
394 
395 static struct notifier_block kernel_offset_notifier = {
396 	.notifier_call = dump_kernel_offset
397 };
398 
399 static int __init register_kernel_offset_dumper(void)
400 {
401 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
402 		atomic_notifier_chain_register(&panic_notifier_list,
403 					       &kernel_offset_notifier);
404 
405 	return 0;
406 }
407 device_initcall(register_kernel_offset_dumper);
408