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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/cpumask.h>
17#include <linux/efi.h>
18#include <linux/efi-bgrt.h>
19#include <linux/init.h>
20#include <linux/irq.h>
21#include <linux/irqdomain.h>
22#include <linux/irq_work.h>
23#include <linux/memblock.h>
24#include <linux/of_fdt.h>
25#include <linux/smp.h>
26#include <linux/serial_core.h>
27#include <linux/pgtable.h>
28
29#include <acpi/ghes.h>
30#include <asm/cputype.h>
31#include <asm/cpu_ops.h>
32#include <asm/daifflags.h>
33#include <asm/smp_plat.h>
34
35int acpi_noirq = 1; /* skip ACPI IRQ initialization */
36int acpi_disabled = 1;
37EXPORT_SYMBOL(acpi_disabled);
38
39int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
40EXPORT_SYMBOL(acpi_pci_disabled);
41
42static bool param_acpi_off __initdata;
43static bool param_acpi_on __initdata;
44static bool param_acpi_force __initdata;
45
46static int __init parse_acpi(char *arg)
47{
48 if (!arg)
49 return -EINVAL;
50
51 /* "acpi=off" disables both ACPI table parsing and interpreter */
52 if (strcmp(arg, "off") == 0)
53 param_acpi_off = true;
54 else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
55 param_acpi_on = true;
56 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
57 param_acpi_force = true;
58 else
59 return -EINVAL; /* Core will print when we return error */
60
61 return 0;
62}
63early_param("acpi", parse_acpi);
64
65static int __init dt_scan_depth1_nodes(unsigned long node,
66 const char *uname, int depth,
67 void *data)
68{
69 /*
70 * Ignore anything not directly under the root node; we'll
71 * catch its parent instead.
72 */
73 if (depth != 1)
74 return 0;
75
76 if (strcmp(uname, "chosen") == 0)
77 return 0;
78
79 if (strcmp(uname, "hypervisor") == 0 &&
80 of_flat_dt_is_compatible(node, "xen,xen"))
81 return 0;
82
83 /*
84 * This node at depth 1 is neither a chosen node nor a xen node,
85 * which we do not expect.
86 */
87 return 1;
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, 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(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 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
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 &&
209 of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
210 goto done;
211
212 /*
213 * ACPI is disabled at this point. Enable it in order to parse
214 * the ACPI tables and carry out sanity checks
215 */
216 enable_acpi();
217
218 /*
219 * If ACPI tables are initialized and FADT sanity checks passed,
220 * leave ACPI enabled and carry on booting; otherwise disable ACPI
221 * on initialization error.
222 * If acpi=force was passed on the command line it forces ACPI
223 * to be enabled even if its initialization failed.
224 */
225 if (acpi_table_init() || acpi_fadt_sanity_check()) {
226 pr_err("Failed to init ACPI tables\n");
227 if (!param_acpi_force)
228 disable_acpi();
229 }
230
231done:
232 if (acpi_disabled) {
233 if (earlycon_acpi_spcr_enable)
234 early_init_dt_scan_chosen_stdout();
235 } else {
236 acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
237 if (IS_ENABLED(CONFIG_ACPI_BGRT))
238 acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
239 }
240}
241
242pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
243{
244 /*
245 * According to "Table 8 Map: EFI memory types to AArch64 memory
246 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
247 * mapped to a corresponding MAIR attribute encoding.
248 * The EFI memory attribute advises all possible capabilities
249 * of a memory region. We use the most efficient capability.
250 */
251
252 u64 attr;
253
254 attr = efi_mem_attributes(addr);
255 if (attr & EFI_MEMORY_WB)
256 return PAGE_KERNEL;
257 if (attr & EFI_MEMORY_WT)
258 return __pgprot(PROT_NORMAL_WT);
259 if (attr & EFI_MEMORY_WC)
260 return __pgprot(PROT_NORMAL_NC);
261 return __pgprot(PROT_DEVICE_nGnRnE);
262}
263
264void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
265{
266 efi_memory_desc_t *md, *region = NULL;
267 pgprot_t prot;
268
269 if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
270 return NULL;
271
272 for_each_efi_memory_desc(md) {
273 u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
274
275 if (phys < md->phys_addr || phys >= end)
276 continue;
277
278 if (phys + size > end) {
279 pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
280 return NULL;
281 }
282 region = md;
283 break;
284 }
285
286 /*
287 * It is fine for AML to remap regions that are not represented in the
288 * EFI memory map at all, as it only describes normal memory, and MMIO
289 * regions that require a virtual mapping to make them accessible to
290 * the EFI runtime services.
291 */
292 prot = __pgprot(PROT_DEVICE_nGnRnE);
293 if (region) {
294 switch (region->type) {
295 case EFI_LOADER_CODE:
296 case EFI_LOADER_DATA:
297 case EFI_BOOT_SERVICES_CODE:
298 case EFI_BOOT_SERVICES_DATA:
299 case EFI_CONVENTIONAL_MEMORY:
300 case EFI_PERSISTENT_MEMORY:
301 if (memblock_is_map_memory(phys) ||
302 !memblock_is_region_memory(phys, size)) {
303 pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys);
304 return NULL;
305 }
306 /*
307 * Mapping kernel memory is permitted if the region in
308 * question is covered by a single memblock with the
309 * NOMAP attribute set: this enables the use of ACPI
310 * table overrides passed via initramfs, which are
311 * reserved in memory using arch_reserve_mem_area()
312 * below. As this particular use case only requires
313 * read access, fall through to the R/O mapping case.
314 */
315 fallthrough;
316
317 case EFI_RUNTIME_SERVICES_CODE:
318 /*
319 * This would be unusual, but not problematic per se,
320 * as long as we take care not to create a writable
321 * mapping for executable code.
322 */
323 prot = PAGE_KERNEL_RO;
324 break;
325
326 case EFI_ACPI_RECLAIM_MEMORY:
327 /*
328 * ACPI reclaim memory is used to pass firmware tables
329 * and other data that is intended for consumption by
330 * the OS only, which may decide it wants to reclaim
331 * that memory and use it for something else. We never
332 * do that, but we usually add it to the linear map
333 * anyway, in which case we should use the existing
334 * mapping.
335 */
336 if (memblock_is_map_memory(phys))
337 return (void __iomem *)__phys_to_virt(phys);
338 fallthrough;
339
340 default:
341 if (region->attribute & EFI_MEMORY_WB)
342 prot = PAGE_KERNEL;
343 else if (region->attribute & EFI_MEMORY_WT)
344 prot = __pgprot(PROT_NORMAL_WT);
345 else if (region->attribute & EFI_MEMORY_WC)
346 prot = __pgprot(PROT_NORMAL_NC);
347 }
348 }
349 return __ioremap(phys, size, prot);
350}
351
352/*
353 * Claim Synchronous External Aborts as a firmware first notification.
354 *
355 * Used by KVM and the arch do_sea handler.
356 * @regs may be NULL when called from process context.
357 */
358int apei_claim_sea(struct pt_regs *regs)
359{
360 int err = -ENOENT;
361 bool return_to_irqs_enabled;
362 unsigned long current_flags;
363
364 if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
365 return err;
366
367 current_flags = local_daif_save_flags();
368
369 /* current_flags isn't useful here as daif doesn't tell us about pNMI */
370 return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
371
372 if (regs)
373 return_to_irqs_enabled = interrupts_enabled(regs);
374
375 /*
376 * SEA can interrupt SError, mask it and describe this as an NMI so
377 * that APEI defers the handling.
378 */
379 local_daif_restore(DAIF_ERRCTX);
380 nmi_enter();
381 err = ghes_notify_sea();
382 nmi_exit();
383
384 /*
385 * APEI NMI-like notifications are deferred to irq_work. Unless
386 * we interrupted irqs-masked code, we can do that now.
387 */
388 if (!err) {
389 if (return_to_irqs_enabled) {
390 local_daif_restore(DAIF_PROCCTX_NOIRQ);
391 __irq_enter();
392 irq_work_run();
393 __irq_exit();
394 } else {
395 pr_warn_ratelimited("APEI work queued but not completed");
396 err = -EINPROGRESS;
397 }
398 }
399
400 local_daif_restore(current_flags);
401
402 return err;
403}
404
405void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
406{
407 memblock_mark_nomap(addr, size);
408}