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
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
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 */
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
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
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 */
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 */
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 */
198 void __init acpi_boot_table_init(void)
199 {
200 /*
201 * Enable ACPI instead of device tree unless
202 * - ACPI has been disabled explicitly (acpi=off), or
203 * - the device tree is not empty (it has more than just a /chosen node,
204 * and a /hypervisor node when running on Xen)
205 * and ACPI has not been [force] enabled (acpi=on|force)
206 */
207 if (param_acpi_off ||
208 (!param_acpi_on && !param_acpi_force && !dt_is_stub()))
209 goto done;
210
211 /*
212 * ACPI is disabled at this point. Enable it in order to parse
213 * the ACPI tables and carry out sanity checks
214 */
215 enable_acpi();
216
217 /*
218 * If ACPI tables are initialized and FADT sanity checks passed,
219 * leave ACPI enabled and carry on booting; otherwise disable ACPI
220 * on initialization error.
221 * If acpi=force was passed on the command line it forces ACPI
222 * to be enabled even if its initialization failed.
223 */
224 if (acpi_table_init() || acpi_fadt_sanity_check()) {
225 pr_err("Failed to init ACPI tables\n");
226 if (!param_acpi_force)
227 disable_acpi();
228 }
229
230 done:
231 if (acpi_disabled) {
232 if (earlycon_acpi_spcr_enable)
233 early_init_dt_scan_chosen_stdout();
234 } else {
235 #ifdef CONFIG_HIBERNATION
236 struct acpi_table_header *facs = NULL;
237 acpi_get_table(ACPI_SIG_FACS, 1, &facs);
238 if (facs) {
239 swsusp_hardware_signature =
240 ((struct acpi_table_facs *)facs)->hardware_signature;
241 acpi_put_table(facs);
242 }
243 #endif
244
245 /*
246 * For varying privacy and security reasons, sometimes need
247 * to completely silence the serial console output, and only
248 * enable it when needed.
249 * But there are many existing systems that depend on this
250 * behaviour, use acpi=nospcr to disable console in ACPI SPCR
251 * table as default serial console.
252 */
253 acpi_parse_spcr(earlycon_acpi_spcr_enable,
254 !param_acpi_nospcr);
255 pr_info("Use ACPI SPCR as default console: %s\n",
256 param_acpi_nospcr ? "No" : "Yes");
257
258 if (IS_ENABLED(CONFIG_ACPI_BGRT))
259 acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
260 }
261 }
262
263 static pgprot_t __acpi_get_writethrough_mem_attribute(void)
264 {
265 /*
266 * Although UEFI specifies the use of Normal Write-through for
267 * EFI_MEMORY_WT, it is seldom used in practice and not implemented
268 * by most (all?) CPUs. Rather than allocate a MAIR just for this
269 * purpose, emit a warning and use Normal Non-cacheable instead.
270 */
271 pr_warn_once("No MAIR allocation for EFI_MEMORY_WT; treating as Normal Non-cacheable\n");
272 return __pgprot(PROT_NORMAL_NC);
273 }
274
275 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
276 {
277 /*
278 * According to "Table 8 Map: EFI memory types to AArch64 memory
279 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
280 * mapped to a corresponding MAIR attribute encoding.
281 * The EFI memory attribute advises all possible capabilities
282 * of a memory region.
283 */
284
285 u64 attr;
286
287 attr = efi_mem_attributes(addr);
288 if (attr & EFI_MEMORY_WB)
289 return PAGE_KERNEL;
290 if (attr & EFI_MEMORY_WC)
291 return __pgprot(PROT_NORMAL_NC);
292 if (attr & EFI_MEMORY_WT)
293 return __acpi_get_writethrough_mem_attribute();
294 return __pgprot(PROT_DEVICE_nGnRnE);
295 }
296
297 void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
298 {
299 efi_memory_desc_t *md, *region = NULL;
300 pgprot_t prot;
301
302 if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
303 return NULL;
304
305 for_each_efi_memory_desc(md) {
306 u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
307
308 if (phys < md->phys_addr || phys >= end)
309 continue;
310
311 if (phys + size > end) {
312 pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
313 return NULL;
314 }
315 region = md;
316 break;
317 }
318
319 /*
320 * It is fine for AML to remap regions that are not represented in the
321 * EFI memory map at all, as it only describes normal memory, and MMIO
322 * regions that require a virtual mapping to make them accessible to
323 * the EFI runtime services.
324 */
325 prot = __pgprot(PROT_DEVICE_nGnRnE);
326 if (region) {
327 switch (region->type) {
328 case EFI_LOADER_CODE:
329 case EFI_LOADER_DATA:
330 case EFI_BOOT_SERVICES_CODE:
331 case EFI_BOOT_SERVICES_DATA:
332 case EFI_CONVENTIONAL_MEMORY:
333 case EFI_PERSISTENT_MEMORY:
334 if (memblock_is_map_memory(phys) ||
335 !memblock_is_region_memory(phys, size)) {
336 pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys);
337 return NULL;
338 }
339 /*
340 * Mapping kernel memory is permitted if the region in
341 * question is covered by a single memblock with the
342 * NOMAP attribute set: this enables the use of ACPI
343 * table overrides passed via initramfs, which are
344 * reserved in memory using arch_reserve_mem_area()
345 * below. As this particular use case only requires
346 * read access, fall through to the R/O mapping case.
347 */
348 fallthrough;
349
350 case EFI_RUNTIME_SERVICES_CODE:
351 /*
352 * This would be unusual, but not problematic per se,
353 * as long as we take care not to create a writable
354 * mapping for executable code.
355 */
356 prot = PAGE_KERNEL_RO;
357 break;
358
359 case EFI_ACPI_RECLAIM_MEMORY:
360 /*
361 * ACPI reclaim memory is used to pass firmware tables
362 * and other data that is intended for consumption by
363 * the OS only, which may decide it wants to reclaim
364 * that memory and use it for something else. We never
365 * do that, but we usually add it to the linear map
366 * anyway, in which case we should use the existing
367 * mapping.
368 */
369 if (memblock_is_map_memory(phys))
370 return (void __iomem *)__phys_to_virt(phys);
371 fallthrough;
372
373 default:
374 if (region->attribute & EFI_MEMORY_WB)
375 prot = PAGE_KERNEL;
376 else if (region->attribute & EFI_MEMORY_WC)
377 prot = __pgprot(PROT_NORMAL_NC);
378 else if (region->attribute & EFI_MEMORY_WT)
379 prot = __acpi_get_writethrough_mem_attribute();
380 }
381 }
382 return ioremap_prot(phys, size, pgprot_val(prot));
383 }
384
385 /*
386 * Claim Synchronous External Aborts as a firmware first notification.
387 *
388 * Used by KVM and the arch do_sea handler.
389 * @regs may be NULL when called from process context.
390 */
391 int apei_claim_sea(struct pt_regs *regs)
392 {
393 int err = -ENOENT;
394 bool return_to_irqs_enabled;
395 unsigned long current_flags;
396
397 if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
398 return err;
399
400 current_flags = local_daif_save_flags();
401
402 /* current_flags isn't useful here as daif doesn't tell us about pNMI */
403 return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
404
405 if (regs)
406 return_to_irqs_enabled = interrupts_enabled(regs);
407
408 /*
409 * SEA can interrupt SError, mask it and describe this as an NMI so
410 * that APEI defers the handling.
411 */
412 local_daif_restore(DAIF_ERRCTX);
413 nmi_enter();
414 err = ghes_notify_sea();
415 nmi_exit();
416
417 /*
418 * APEI NMI-like notifications are deferred to irq_work. Unless
419 * we interrupted irqs-masked code, we can do that now.
420 */
421 if (!err) {
422 if (return_to_irqs_enabled) {
423 local_daif_restore(DAIF_PROCCTX_NOIRQ);
424 __irq_enter();
425 irq_work_run();
426 __irq_exit();
427 } else {
428 pr_warn_ratelimited("APEI work queued but not completed");
429 err = -EINPROGRESS;
430 }
431 }
432
433 local_daif_restore(current_flags);
434
435 return err;
436 }
437
438 void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
439 {
440 memblock_mark_nomap(addr, size);
441 }
442
443 #ifdef CONFIG_ACPI_HOTPLUG_CPU
444 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id,
445 int *pcpu)
446 {
447 /* If an error code is passed in this stub can't fix it */
448 if (*pcpu < 0) {
449 pr_warn_once("Unable to map CPU to valid ID\n");
450 return *pcpu;
451 }
452
453 return 0;
454 }
455 EXPORT_SYMBOL(acpi_map_cpu);
456
457 int acpi_unmap_cpu(int cpu)
458 {
459 return 0;
460 }
461 EXPORT_SYMBOL(acpi_unmap_cpu);
462 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
463
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