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 /*
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
256 if (IS_ENABLED(CONFIG_ACPI_BGRT))
257 acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
258 }
259 }
260
__acpi_get_writethrough_mem_attribute(void)261 static 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
__acpi_get_mem_attribute(phys_addr_t addr)273 pgprot_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(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
acpi_os_ioremap(acpi_physical_address phys,acpi_size size)295 void __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(phys) ||
333 !memblock_is_region_memory(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 fallthrough;
355
356 case EFI_ACPI_MEMORY_NVS:
357 /*
358 * ACPI NVS marks an area reserved for use by the
359 * firmware, even after exiting the boot service.
360 * This may be used by the firmware for sharing dynamic
361 * tables/data (e.g., ACPI CCEL) with the OS. Map it
362 * as read-only.
363 */
364 prot = PAGE_KERNEL_RO;
365 break;
366
367 case EFI_ACPI_RECLAIM_MEMORY:
368 /*
369 * ACPI reclaim memory is used to pass firmware tables
370 * and other data that is intended for consumption by
371 * the OS only, which may decide it wants to reclaim
372 * that memory and use it for something else. We never
373 * do that, but we usually add it to the linear map
374 * anyway, in which case we should use the existing
375 * mapping.
376 */
377 if (memblock_is_map_memory(phys))
378 return (void __iomem *)__phys_to_virt(phys);
379 fallthrough;
380
381 default:
382 if (region->attribute & EFI_MEMORY_WB)
383 prot = PAGE_KERNEL;
384 else if (region->attribute & EFI_MEMORY_WC)
385 prot = __pgprot(PROT_NORMAL_NC);
386 else if (region->attribute & EFI_MEMORY_WT)
387 prot = __acpi_get_writethrough_mem_attribute();
388 }
389 }
390 return ioremap_prot(phys, size, prot);
391 }
392
393 /*
394 * Claim Synchronous External Aborts as a firmware first notification.
395 *
396 * Used by KVM and the arch do_sea handler.
397 * @regs may be NULL when called from process context.
398 */
apei_claim_sea(struct pt_regs * regs)399 int apei_claim_sea(struct pt_regs *regs)
400 {
401 int err = -ENOENT;
402 bool return_to_irqs_enabled;
403 unsigned long current_flags;
404
405 if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
406 return err;
407
408 current_flags = local_daif_save_flags();
409
410 /* current_flags isn't useful here as daif doesn't tell us about pNMI */
411 return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
412
413 if (regs)
414 return_to_irqs_enabled = !regs_irqs_disabled(regs);
415
416 /*
417 * SEA can interrupt SError, mask it and describe this as an NMI so
418 * that APEI defers the handling.
419 */
420 local_daif_restore(DAIF_ERRCTX);
421 nmi_enter();
422 err = ghes_notify_sea();
423 nmi_exit();
424
425 /*
426 * APEI NMI-like notifications are deferred to irq_work. Unless
427 * we interrupted irqs-masked code, we can do that now.
428 */
429 if (!err) {
430 if (return_to_irqs_enabled) {
431 local_daif_restore(DAIF_PROCCTX_NOIRQ);
432 __irq_enter();
433 irq_work_run();
434 __irq_exit();
435 } else {
436 pr_warn_ratelimited("APEI work queued but not completed");
437 err = -EINPROGRESS;
438 }
439 }
440
441 local_daif_restore(current_flags);
442
443 return err;
444 }
445
arch_reserve_mem_area(acpi_physical_address addr,size_t size)446 void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
447 {
448 memblock_mark_nomap(addr, size);
449 }
450
451 #ifdef CONFIG_ACPI_HOTPLUG_CPU
acpi_map_cpu(acpi_handle handle,phys_cpuid_t physid,u32 apci_id,int * pcpu)452 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id,
453 int *pcpu)
454 {
455 /* If an error code is passed in this stub can't fix it */
456 if (*pcpu < 0) {
457 pr_warn_once("Unable to map CPU to valid ID\n");
458 return *pcpu;
459 }
460
461 return 0;
462 }
463 EXPORT_SYMBOL(acpi_map_cpu);
464
acpi_unmap_cpu(int cpu)465 int acpi_unmap_cpu(int cpu)
466 {
467 return 0;
468 }
469 EXPORT_SYMBOL(acpi_unmap_cpu);
470 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
471