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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
39int acpi_noirq = 1; /* skip ACPI IRQ initialization */
40int acpi_disabled = 1;
41EXPORT_SYMBOL(acpi_disabled);
42
43int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
44EXPORT_SYMBOL(acpi_pci_disabled);
45
46static bool param_acpi_off __initdata;
47static bool param_acpi_on __initdata;
48static bool param_acpi_force __initdata;
49static bool param_acpi_nospcr __initdata;
50
51static 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}
70early_param("acpi", parse_acpi);
71
72static 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(fdt: initial_boot_params, nodeoffset: node, NULL);
78 if (strcmp(name, "chosen") == 0)
79 continue;
80 if (strcmp(name, "hypervisor") == 0 &&
81 of_flat_dt_is_compatible(node, name: "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 */
94void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
95{
96 if (!size)
97 return NULL;
98
99 return early_memremap(phys_addr: phys, size);
100}
101
102void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
103{
104 if (!map || !size)
105 return;
106
107 early_memunmap(addr: map, size);
108}
109
110bool __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 */
116bool 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 */
127static 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 compliance tests
137 */
138 status = acpi_get_table(ACPI_SIG_FADT, instance: 0, out_table: &table);
139 if (ACPI_FAILURE(status)) {
140 const char *msg = acpi_format_exception(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
171out:
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 */
198void __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
230done:
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, instance: 1, out_table: &facs);
238 if (facs) {
239 swsusp_hardware_signature =
240 ((struct acpi_table_facs *)facs)->hardware_signature;
241 acpi_put_table(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(enable_earlycon: earlycon_acpi_spcr_enable,
254 enable_console: !param_acpi_nospcr);
255
256 if (IS_ENABLED(CONFIG_ACPI_BGRT))
257 acpi_table_parse(ACPI_SIG_BGRT, handler: acpi_parse_bgrt);
258 }
259}
260
261static pgprot_t __acpi_get_writethrough_mem_attribute(void)
262{
263 /*
264 * Although UEFI specifies the use of Normal Write-through for
265 * EFI_MEMORY_WT, it is seldom used in practice and not implemented
266 * by most (all?) CPUs. Rather than allocate a MAIR just for this
267 * purpose, emit a warning and use Normal Non-cacheable instead.
268 */
269 pr_warn_once("No MAIR allocation for EFI_MEMORY_WT; treating as Normal Non-cacheable\n");
270 return __pgprot(PROT_NORMAL_NC);
271}
272
273pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
274{
275 /*
276 * According to "Table 8 Map: EFI memory types to AArch64 memory
277 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
278 * mapped to a corresponding MAIR attribute encoding.
279 * The EFI memory attribute advises all possible capabilities
280 * of a memory region.
281 */
282
283 u64 attr;
284
285 attr = efi_mem_attributes(phys_addr: addr);
286 if (attr & EFI_MEMORY_WB)
287 return PAGE_KERNEL;
288 if (attr & EFI_MEMORY_WC)
289 return __pgprot(PROT_NORMAL_NC);
290 if (attr & EFI_MEMORY_WT)
291 return __acpi_get_writethrough_mem_attribute();
292 return __pgprot(PROT_DEVICE_nGnRnE);
293}
294
295void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
296{
297 efi_memory_desc_t *md, *region = NULL;
298 pgprot_t prot;
299
300 if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
301 return NULL;
302
303 for_each_efi_memory_desc(md) {
304 u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
305
306 if (phys < md->phys_addr || phys >= end)
307 continue;
308
309 if (phys + size > end) {
310 pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
311 return NULL;
312 }
313 region = md;
314 break;
315 }
316
317 /*
318 * It is fine for AML to remap regions that are not represented in the
319 * EFI memory map at all, as it only describes normal memory, and MMIO
320 * regions that require a virtual mapping to make them accessible to
321 * the EFI runtime services.
322 */
323 prot = __pgprot(PROT_DEVICE_nGnRnE);
324 if (region) {
325 switch (region->type) {
326 case EFI_LOADER_CODE:
327 case EFI_LOADER_DATA:
328 case EFI_BOOT_SERVICES_CODE:
329 case EFI_BOOT_SERVICES_DATA:
330 case EFI_CONVENTIONAL_MEMORY:
331 case EFI_PERSISTENT_MEMORY:
332 if (memblock_is_map_memory(addr: phys) ||
333 !memblock_is_region_memory(base: phys, size)) {
334 pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys);
335 return NULL;
336 }
337 /*
338 * Mapping kernel memory is permitted if the region in
339 * question is covered by a single memblock with the
340 * NOMAP attribute set: this enables the use of ACPI
341 * table overrides passed via initramfs, which are
342 * reserved in memory using arch_reserve_mem_area()
343 * below. As this particular use case only requires
344 * read access, fall through to the R/O mapping case.
345 */
346 fallthrough;
347
348 case EFI_RUNTIME_SERVICES_CODE:
349 /*
350 * This would be unusual, but not problematic per se,
351 * as long as we take care not to create a writable
352 * mapping for executable code.
353 */
354 prot = PAGE_KERNEL_RO;
355 break;
356
357 case EFI_ACPI_RECLAIM_MEMORY:
358 /*
359 * ACPI reclaim memory is used to pass firmware tables
360 * and other data that is intended for consumption by
361 * the OS only, which may decide it wants to reclaim
362 * that memory and use it for something else. We never
363 * do that, but we usually add it to the linear map
364 * anyway, in which case we should use the existing
365 * mapping.
366 */
367 if (memblock_is_map_memory(addr: phys))
368 return (void __iomem *)__phys_to_virt(phys);
369 fallthrough;
370
371 default:
372 if (region->attribute & EFI_MEMORY_WB)
373 prot = PAGE_KERNEL;
374 else if (region->attribute & EFI_MEMORY_WC)
375 prot = __pgprot(PROT_NORMAL_NC);
376 else if (region->attribute & EFI_MEMORY_WT)
377 prot = __acpi_get_writethrough_mem_attribute();
378 }
379 }
380 return ioremap_prot(offset: phys, size, prot);
381}
382
383/*
384 * Claim Synchronous External Aborts as a firmware first notification.
385 *
386 * Used by KVM and the arch do_sea handler.
387 * @regs may be NULL when called from process context.
388 */
389int apei_claim_sea(struct pt_regs *regs)
390{
391 int err = -ENOENT;
392 bool return_to_irqs_enabled;
393 unsigned long current_flags;
394
395 if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
396 return err;
397
398 current_flags = local_daif_save_flags();
399
400 /* current_flags isn't useful here as daif doesn't tell us about pNMI */
401 return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
402
403 if (regs)
404 return_to_irqs_enabled = !regs_irqs_disabled(regs);
405
406 /*
407 * SEA can interrupt SError, mask it and describe this as an NMI so
408 * that APEI defers the handling.
409 */
410 local_daif_restore(DAIF_ERRCTX);
411 nmi_enter();
412 err = ghes_notify_sea();
413 nmi_exit();
414
415 /*
416 * APEI NMI-like notifications are deferred to irq_work. Unless
417 * we interrupted irqs-masked code, we can do that now.
418 */
419 if (!err) {
420 if (return_to_irqs_enabled) {
421 local_daif_restore(DAIF_PROCCTX_NOIRQ);
422 __irq_enter();
423 irq_work_run();
424 __irq_exit();
425 } else {
426 pr_warn_ratelimited("APEI work queued but not completed\n");
427 err = -EINPROGRESS;
428 }
429 }
430
431 local_daif_restore(current_flags);
432
433 return err;
434}
435
436void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
437{
438 memblock_mark_nomap(base: addr, size);
439}
440
441#ifdef CONFIG_ACPI_HOTPLUG_CPU
442int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id,
443 int *pcpu)
444{
445 /* If an error code is passed in this stub can't fix it */
446 if (*pcpu < 0) {
447 pr_warn_once("Unable to map CPU to valid ID\n");
448 return *pcpu;
449 }
450
451 return 0;
452}
453EXPORT_SYMBOL(acpi_map_cpu);
454
455int acpi_unmap_cpu(int cpu)
456{
457 return 0;
458}
459EXPORT_SYMBOL(acpi_unmap_cpu);
460#endif /* CONFIG_ACPI_HOTPLUG_CPU */
461

source code of linux/arch/arm64/kernel/acpi.c