xref: /linux/arch/arm64/kernel/acpi.c (revision 6fb44438a5e1897a72dd11139274735256be8069)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  ARM64 Specific Low-Level ACPI Boot Support
4  *
5  *  Copyright (C) 2013-2014, Linaro Ltd.
6  *	Author: Al Stone <al.stone@linaro.org>
7  *	Author: Graeme Gregory <graeme.gregory@linaro.org>
8  *	Author: Hanjun Guo <hanjun.guo@linaro.org>
9  *	Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
10  *	Author: Naresh Bhat <naresh.bhat@linaro.org>
11  */
12 
13 #define pr_fmt(fmt) "ACPI: " fmt
14 
15 #include <linux/acpi.h>
16 #include <linux/arm-smccc.h>
17 #include <linux/cpumask.h>
18 #include <linux/efi.h>
19 #include <linux/efi-bgrt.h>
20 #include <linux/init.h>
21 #include <linux/irq.h>
22 #include <linux/irqdomain.h>
23 #include <linux/irq_work.h>
24 #include <linux/memblock.h>
25 #include <linux/of_fdt.h>
26 #include <linux/libfdt.h>
27 #include <linux/smp.h>
28 #include <linux/serial_core.h>
29 #include <linux/suspend.h>
30 #include <linux/pgtable.h>
31 
32 #include <acpi/ghes.h>
33 #include <acpi/processor.h>
34 #include <asm/cputype.h>
35 #include <asm/cpu_ops.h>
36 #include <asm/daifflags.h>
37 #include <asm/smp_plat.h>
38 
39 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
40 int acpi_disabled = 1;
41 EXPORT_SYMBOL(acpi_disabled);
42 
43 int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
44 EXPORT_SYMBOL(acpi_pci_disabled);
45 
46 static bool param_acpi_off __initdata;
47 static bool param_acpi_on __initdata;
48 static bool param_acpi_force __initdata;
49 static bool param_acpi_nospcr __initdata;
50 
parse_acpi(char * arg)51 static int __init parse_acpi(char *arg)
52 {
53 	if (!arg)
54 		return -EINVAL;
55 
56 	/* "acpi=off" disables both ACPI table parsing and interpreter */
57 	if (strcmp(arg, "off") == 0)
58 		param_acpi_off = true;
59 	else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
60 		param_acpi_on = true;
61 	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
62 		param_acpi_force = true;
63 	else if (strcmp(arg, "nospcr") == 0) /* disable SPCR as default console */
64 		param_acpi_nospcr = true;
65 	else
66 		return -EINVAL;	/* Core will print when we return error */
67 
68 	return 0;
69 }
70 early_param("acpi", parse_acpi);
71 
dt_is_stub(void)72 static bool __init dt_is_stub(void)
73 {
74 	int node;
75 
76 	fdt_for_each_subnode(node, initial_boot_params, 0) {
77 		const char *name = fdt_get_name(initial_boot_params, node, NULL);
78 		if (strcmp(name, "chosen") == 0)
79 			continue;
80 		if (strcmp(name, "hypervisor") == 0 &&
81 		    of_flat_dt_is_compatible(node, "xen,xen"))
82 			continue;
83 
84 		return false;
85 	}
86 
87 	return true;
88 }
89 
90 /*
91  * __acpi_map_table() will be called before page_init(), so early_ioremap()
92  * or early_memremap() should be called here to for ACPI table mapping.
93  */
__acpi_map_table(unsigned long phys,unsigned long size)94 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
95 {
96 	if (!size)
97 		return NULL;
98 
99 	return early_memremap(phys, size);
100 }
101 
__acpi_unmap_table(void __iomem * map,unsigned long size)102 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
103 {
104 	if (!map || !size)
105 		return;
106 
107 	early_memunmap(map, size);
108 }
109 
acpi_psci_present(void)110 bool __init acpi_psci_present(void)
111 {
112 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
113 }
114 
115 /* Whether HVC must be used instead of SMC as the PSCI conduit */
acpi_psci_use_hvc(void)116 bool acpi_psci_use_hvc(void)
117 {
118 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
119 }
120 
121 /*
122  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
123  *			      checks on it
124  *
125  * Return 0 on success,  <0 on failure
126  */
acpi_fadt_sanity_check(void)127 static int __init acpi_fadt_sanity_check(void)
128 {
129 	struct acpi_table_header *table;
130 	struct acpi_table_fadt *fadt;
131 	acpi_status status;
132 	int ret = 0;
133 
134 	/*
135 	 * FADT is required on arm64; retrieve it to check its presence
136 	 * and carry out revision and ACPI HW reduced compliancy tests
137 	 */
138 	status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
139 	if (ACPI_FAILURE(status)) {
140 		const char *msg = acpi_format_exception(status);
141 
142 		pr_err("Failed to get FADT table, %s\n", msg);
143 		return -ENODEV;
144 	}
145 
146 	fadt = (struct acpi_table_fadt *)table;
147 
148 	/*
149 	 * Revision in table header is the FADT Major revision, and there
150 	 * is a minor revision of FADT which was introduced by ACPI 5.1,
151 	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
152 	 * boot protocol configuration data.
153 	 */
154 	if (table->revision < 5 ||
155 	   (table->revision == 5 && fadt->minor_revision < 1)) {
156 		pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 5.1+\n",
157 		       table->revision, fadt->minor_revision);
158 
159 		if (!fadt->arm_boot_flags) {
160 			ret = -EINVAL;
161 			goto out;
162 		}
163 		pr_err("FADT has ARM boot flags set, assuming 5.1\n");
164 	}
165 
166 	if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
167 		pr_err("FADT not ACPI hardware reduced compliant\n");
168 		ret = -EINVAL;
169 	}
170 
171 out:
172 	/*
173 	 * acpi_get_table() creates FADT table mapping that
174 	 * should be released after parsing and before resuming boot
175 	 */
176 	acpi_put_table(table);
177 	return ret;
178 }
179 
180 /*
181  * acpi_boot_table_init() called from setup_arch(), always.
182  *	1. find RSDP and get its address, and then find XSDT
183  *	2. extract all tables and checksums them all
184  *	3. check ACPI FADT revision
185  *	4. check ACPI FADT HW reduced flag
186  *
187  * We can parse ACPI boot-time tables such as MADT after
188  * this function is called.
189  *
190  * On return ACPI is enabled if either:
191  *
192  * - ACPI tables are initialized and sanity checks passed
193  * - acpi=force was passed in the command line and ACPI was not disabled
194  *   explicitly through acpi=off command line parameter
195  *
196  * ACPI is disabled on function return otherwise
197  */
acpi_boot_table_init(void)198 void __init acpi_boot_table_init(void)
199 {
200 	int ret;
201 
202 	/*
203 	 * Enable ACPI instead of device tree unless
204 	 * - ACPI has been disabled explicitly (acpi=off), or
205 	 * - the device tree is not empty (it has more than just a /chosen node,
206 	 *   and a /hypervisor node when running on Xen)
207 	 *   and ACPI has not been [force] enabled (acpi=on|force)
208 	 */
209 	if (param_acpi_off ||
210 	    (!param_acpi_on && !param_acpi_force && !dt_is_stub()))
211 		goto done;
212 
213 	/*
214 	 * ACPI is disabled at this point. Enable it in order to parse
215 	 * the ACPI tables and carry out sanity checks
216 	 */
217 	enable_acpi();
218 
219 	/*
220 	 * If ACPI tables are initialized and FADT sanity checks passed,
221 	 * leave ACPI enabled and carry on booting; otherwise disable ACPI
222 	 * on initialization error.
223 	 * If acpi=force was passed on the command line it forces ACPI
224 	 * to be enabled even if its initialization failed.
225 	 */
226 	if (acpi_table_init() || acpi_fadt_sanity_check()) {
227 		pr_err("Failed to init ACPI tables\n");
228 		if (!param_acpi_force)
229 			disable_acpi();
230 	}
231 
232 done:
233 	if (acpi_disabled) {
234 		if (earlycon_acpi_spcr_enable)
235 			early_init_dt_scan_chosen_stdout();
236 	} else {
237 #ifdef CONFIG_HIBERNATION
238 		struct acpi_table_header *facs = NULL;
239 		acpi_get_table(ACPI_SIG_FACS, 1, &facs);
240 		if (facs) {
241 			swsusp_hardware_signature =
242 				((struct acpi_table_facs *)facs)->hardware_signature;
243 			acpi_put_table(facs);
244 		}
245 #endif
246 
247 		/*
248 		 * For varying privacy and security reasons, sometimes need
249 		 * to completely silence the serial console output, and only
250 		 * enable it when needed.
251 		 * But there are many existing systems that depend on this
252 		 * behaviour, use acpi=nospcr to disable console in ACPI SPCR
253 		 * table as default serial console.
254 		 */
255 		ret = acpi_parse_spcr(earlycon_acpi_spcr_enable,
256 			!param_acpi_nospcr);
257 		if (!ret || param_acpi_nospcr || !IS_ENABLED(CONFIG_ACPI_SPCR_TABLE))
258 			pr_info("Use ACPI SPCR as default console: No\n");
259 		else
260 			pr_info("Use ACPI SPCR as default console: Yes\n");
261 
262 		if (IS_ENABLED(CONFIG_ACPI_BGRT))
263 			acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
264 	}
265 }
266 
__acpi_get_writethrough_mem_attribute(void)267 static pgprot_t __acpi_get_writethrough_mem_attribute(void)
268 {
269 	/*
270 	 * Although UEFI specifies the use of Normal Write-through for
271 	 * EFI_MEMORY_WT, it is seldom used in practice and not implemented
272 	 * by most (all?) CPUs. Rather than allocate a MAIR just for this
273 	 * purpose, emit a warning and use Normal Non-cacheable instead.
274 	 */
275 	pr_warn_once("No MAIR allocation for EFI_MEMORY_WT; treating as Normal Non-cacheable\n");
276 	return __pgprot(PROT_NORMAL_NC);
277 }
278 
__acpi_get_mem_attribute(phys_addr_t addr)279 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
280 {
281 	/*
282 	 * According to "Table 8 Map: EFI memory types to AArch64 memory
283 	 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
284 	 * mapped to a corresponding MAIR attribute encoding.
285 	 * The EFI memory attribute advises all possible capabilities
286 	 * of a memory region.
287 	 */
288 
289 	u64 attr;
290 
291 	attr = efi_mem_attributes(addr);
292 	if (attr & EFI_MEMORY_WB)
293 		return PAGE_KERNEL;
294 	if (attr & EFI_MEMORY_WC)
295 		return __pgprot(PROT_NORMAL_NC);
296 	if (attr & EFI_MEMORY_WT)
297 		return __acpi_get_writethrough_mem_attribute();
298 	return __pgprot(PROT_DEVICE_nGnRnE);
299 }
300 
acpi_os_ioremap(acpi_physical_address phys,acpi_size size)301 void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
302 {
303 	efi_memory_desc_t *md, *region = NULL;
304 	pgprot_t prot;
305 
306 	if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
307 		return NULL;
308 
309 	for_each_efi_memory_desc(md) {
310 		u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
311 
312 		if (phys < md->phys_addr || phys >= end)
313 			continue;
314 
315 		if (phys + size > end) {
316 			pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
317 			return NULL;
318 		}
319 		region = md;
320 		break;
321 	}
322 
323 	/*
324 	 * It is fine for AML to remap regions that are not represented in the
325 	 * EFI memory map at all, as it only describes normal memory, and MMIO
326 	 * regions that require a virtual mapping to make them accessible to
327 	 * the EFI runtime services.
328 	 */
329 	prot = __pgprot(PROT_DEVICE_nGnRnE);
330 	if (region) {
331 		switch (region->type) {
332 		case EFI_LOADER_CODE:
333 		case EFI_LOADER_DATA:
334 		case EFI_BOOT_SERVICES_CODE:
335 		case EFI_BOOT_SERVICES_DATA:
336 		case EFI_CONVENTIONAL_MEMORY:
337 		case EFI_PERSISTENT_MEMORY:
338 			if (memblock_is_map_memory(phys) ||
339 			    !memblock_is_region_memory(phys, size)) {
340 				pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys);
341 				return NULL;
342 			}
343 			/*
344 			 * Mapping kernel memory is permitted if the region in
345 			 * question is covered by a single memblock with the
346 			 * NOMAP attribute set: this enables the use of ACPI
347 			 * table overrides passed via initramfs, which are
348 			 * reserved in memory using arch_reserve_mem_area()
349 			 * below. As this particular use case only requires
350 			 * read access, fall through to the R/O mapping case.
351 			 */
352 			fallthrough;
353 
354 		case EFI_RUNTIME_SERVICES_CODE:
355 			/*
356 			 * This would be unusual, but not problematic per se,
357 			 * as long as we take care not to create a writable
358 			 * mapping for executable code.
359 			 */
360 			prot = PAGE_KERNEL_RO;
361 			break;
362 
363 		case EFI_ACPI_RECLAIM_MEMORY:
364 			/*
365 			 * ACPI reclaim memory is used to pass firmware tables
366 			 * and other data that is intended for consumption by
367 			 * the OS only, which may decide it wants to reclaim
368 			 * that memory and use it for something else. We never
369 			 * do that, but we usually add it to the linear map
370 			 * anyway, in which case we should use the existing
371 			 * mapping.
372 			 */
373 			if (memblock_is_map_memory(phys))
374 				return (void __iomem *)__phys_to_virt(phys);
375 			fallthrough;
376 
377 		default:
378 			if (region->attribute & EFI_MEMORY_WB)
379 				prot = PAGE_KERNEL;
380 			else if (region->attribute & EFI_MEMORY_WC)
381 				prot = __pgprot(PROT_NORMAL_NC);
382 			else if (region->attribute & EFI_MEMORY_WT)
383 				prot = __acpi_get_writethrough_mem_attribute();
384 		}
385 	}
386 	return ioremap_prot(phys, size, prot);
387 }
388 
389 /*
390  * Claim Synchronous External Aborts as a firmware first notification.
391  *
392  * Used by KVM and the arch do_sea handler.
393  * @regs may be NULL when called from process context.
394  */
apei_claim_sea(struct pt_regs * regs)395 int apei_claim_sea(struct pt_regs *regs)
396 {
397 	int err = -ENOENT;
398 	bool return_to_irqs_enabled;
399 	unsigned long current_flags;
400 
401 	if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
402 		return err;
403 
404 	current_flags = local_daif_save_flags();
405 
406 	/* current_flags isn't useful here as daif doesn't tell us about pNMI */
407 	return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
408 
409 	if (regs)
410 		return_to_irqs_enabled = interrupts_enabled(regs);
411 
412 	/*
413 	 * SEA can interrupt SError, mask it and describe this as an NMI so
414 	 * that APEI defers the handling.
415 	 */
416 	local_daif_restore(DAIF_ERRCTX);
417 	nmi_enter();
418 	err = ghes_notify_sea();
419 	nmi_exit();
420 
421 	/*
422 	 * APEI NMI-like notifications are deferred to irq_work. Unless
423 	 * we interrupted irqs-masked code, we can do that now.
424 	 */
425 	if (!err) {
426 		if (return_to_irqs_enabled) {
427 			local_daif_restore(DAIF_PROCCTX_NOIRQ);
428 			__irq_enter();
429 			irq_work_run();
430 			__irq_exit();
431 		} else {
432 			pr_warn_ratelimited("APEI work queued but not completed");
433 			err = -EINPROGRESS;
434 		}
435 	}
436 
437 	local_daif_restore(current_flags);
438 
439 	return err;
440 }
441 
arch_reserve_mem_area(acpi_physical_address addr,size_t size)442 void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
443 {
444 	memblock_mark_nomap(addr, size);
445 }
446 
447 #ifdef CONFIG_ACPI_HOTPLUG_CPU
acpi_map_cpu(acpi_handle handle,phys_cpuid_t physid,u32 apci_id,int * pcpu)448 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id,
449 		 int *pcpu)
450 {
451 	/* If an error code is passed in this stub can't fix it */
452 	if (*pcpu < 0) {
453 		pr_warn_once("Unable to map CPU to valid ID\n");
454 		return *pcpu;
455 	}
456 
457 	return 0;
458 }
459 EXPORT_SYMBOL(acpi_map_cpu);
460 
acpi_unmap_cpu(int cpu)461 int acpi_unmap_cpu(int cpu)
462 {
463 	return 0;
464 }
465 EXPORT_SYMBOL(acpi_unmap_cpu);
466 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
467