1 // SPDX-License-Identifier: GPL-2.0-only
3 * ARM64 Specific Low-Level ACPI Boot Support
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>
13 #define pr_fmt(fmt) "ACPI: " fmt
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>
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>
35 int acpi_noirq = 1; /* skip ACPI IRQ initialization */
36 int acpi_disabled = 1;
37 EXPORT_SYMBOL(acpi_disabled);
39 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
40 EXPORT_SYMBOL(acpi_pci_disabled);
42 static bool param_acpi_off __initdata;
43 static bool param_acpi_on __initdata;
44 static bool param_acpi_force __initdata;
46 static int __init parse_acpi(char *arg)
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 */
56 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
57 param_acpi_force = true;
59 return -EINVAL; /* Core will print when we return error */
63 early_param("acpi", parse_acpi);
65 static int __init dt_scan_depth1_nodes(unsigned long node,
66 const char *uname, int depth,
70 * Ignore anything not directly under the root node; we'll
71 * catch its parent instead.
76 if (strcmp(uname, "chosen") == 0)
79 if (strcmp(uname, "hypervisor") == 0 &&
80 of_flat_dt_is_compatible(node, "xen,xen"))
84 * This node at depth 1 is neither a chosen node nor a xen node,
85 * which we do not expect.
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.
94 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
99 return early_memremap(phys, size);
102 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
107 early_memunmap(map, size);
110 bool __init acpi_psci_present(void)
112 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
115 /* Whether HVC must be used instead of SMC as the PSCI conduit */
116 bool acpi_psci_use_hvc(void)
118 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
122 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
125 * Return 0 on success, <0 on failure
127 static int __init acpi_fadt_sanity_check(void)
129 struct acpi_table_header *table;
130 struct acpi_table_fadt *fadt;
135 * FADT is required on arm64; retrieve it to check its presence
136 * and carry out revision and ACPI HW reduced compliancy tests
138 status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
139 if (ACPI_FAILURE(status)) {
140 const char *msg = acpi_format_exception(status);
142 pr_err("Failed to get FADT table, %s\n", msg);
146 fadt = (struct acpi_table_fadt *)table;
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.
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);
159 if (!fadt->arm_boot_flags) {
163 pr_err("FADT has ARM boot flags set, assuming 5.1\n");
166 if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
167 pr_err("FADT not ACPI hardware reduced compliant\n");
173 * acpi_get_table() creates FADT table mapping that
174 * should be released after parsing and before resuming boot
176 acpi_put_table(table);
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
187 * We can parse ACPI boot-time tables such as MADT after
188 * this function is called.
190 * On return ACPI is enabled if either:
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
196 * ACPI is disabled on function return otherwise
198 void __init acpi_boot_table_init(void)
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)
207 if (param_acpi_off ||
208 (!param_acpi_on && !param_acpi_force &&
209 of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
213 * ACPI is disabled at this point. Enable it in order to parse
214 * the ACPI tables and carry out sanity checks
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.
225 if (acpi_table_init() || acpi_fadt_sanity_check()) {
226 pr_err("Failed to init ACPI tables\n");
227 if (!param_acpi_force)
233 if (earlycon_acpi_spcr_enable)
234 early_init_dt_scan_chosen_stdout();
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);
242 static pgprot_t __acpi_get_writethrough_mem_attribute(void)
245 * Although UEFI specifies the use of Normal Write-through for
246 * EFI_MEMORY_WT, it is seldom used in practice and not implemented
247 * by most (all?) CPUs. Rather than allocate a MAIR just for this
248 * purpose, emit a warning and use Normal Non-cacheable instead.
250 pr_warn_once("No MAIR allocation for EFI_MEMORY_WT; treating as Normal Non-cacheable\n");
251 return __pgprot(PROT_NORMAL_NC);
254 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
257 * According to "Table 8 Map: EFI memory types to AArch64 memory
258 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
259 * mapped to a corresponding MAIR attribute encoding.
260 * The EFI memory attribute advises all possible capabilities
261 * of a memory region.
266 attr = efi_mem_attributes(addr);
267 if (attr & EFI_MEMORY_WB)
269 if (attr & EFI_MEMORY_WC)
270 return __pgprot(PROT_NORMAL_NC);
271 if (attr & EFI_MEMORY_WT)
272 return __acpi_get_writethrough_mem_attribute();
273 return __pgprot(PROT_DEVICE_nGnRnE);
276 void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
278 efi_memory_desc_t *md, *region = NULL;
281 if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
284 for_each_efi_memory_desc(md) {
285 u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
287 if (phys < md->phys_addr || phys >= end)
290 if (phys + size > end) {
291 pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
299 * It is fine for AML to remap regions that are not represented in the
300 * EFI memory map at all, as it only describes normal memory, and MMIO
301 * regions that require a virtual mapping to make them accessible to
302 * the EFI runtime services.
304 prot = __pgprot(PROT_DEVICE_nGnRnE);
306 switch (region->type) {
307 case EFI_LOADER_CODE:
308 case EFI_LOADER_DATA:
309 case EFI_BOOT_SERVICES_CODE:
310 case EFI_BOOT_SERVICES_DATA:
311 case EFI_CONVENTIONAL_MEMORY:
312 case EFI_PERSISTENT_MEMORY:
313 if (memblock_is_map_memory(phys) ||
314 !memblock_is_region_memory(phys, size)) {
315 pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys);
319 * Mapping kernel memory is permitted if the region in
320 * question is covered by a single memblock with the
321 * NOMAP attribute set: this enables the use of ACPI
322 * table overrides passed via initramfs, which are
323 * reserved in memory using arch_reserve_mem_area()
324 * below. As this particular use case only requires
325 * read access, fall through to the R/O mapping case.
329 case EFI_RUNTIME_SERVICES_CODE:
331 * This would be unusual, but not problematic per se,
332 * as long as we take care not to create a writable
333 * mapping for executable code.
335 prot = PAGE_KERNEL_RO;
338 case EFI_ACPI_RECLAIM_MEMORY:
340 * ACPI reclaim memory is used to pass firmware tables
341 * and other data that is intended for consumption by
342 * the OS only, which may decide it wants to reclaim
343 * that memory and use it for something else. We never
344 * do that, but we usually add it to the linear map
345 * anyway, in which case we should use the existing
348 if (memblock_is_map_memory(phys))
349 return (void __iomem *)__phys_to_virt(phys);
353 if (region->attribute & EFI_MEMORY_WB)
355 else if (region->attribute & EFI_MEMORY_WC)
356 prot = __pgprot(PROT_NORMAL_NC);
357 else if (region->attribute & EFI_MEMORY_WT)
358 prot = __acpi_get_writethrough_mem_attribute();
361 return __ioremap(phys, size, prot);
365 * Claim Synchronous External Aborts as a firmware first notification.
367 * Used by KVM and the arch do_sea handler.
368 * @regs may be NULL when called from process context.
370 int apei_claim_sea(struct pt_regs *regs)
373 bool return_to_irqs_enabled;
374 unsigned long current_flags;
376 if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
379 current_flags = local_daif_save_flags();
381 /* current_flags isn't useful here as daif doesn't tell us about pNMI */
382 return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
385 return_to_irqs_enabled = interrupts_enabled(regs);
388 * SEA can interrupt SError, mask it and describe this as an NMI so
389 * that APEI defers the handling.
391 local_daif_restore(DAIF_ERRCTX);
393 err = ghes_notify_sea();
397 * APEI NMI-like notifications are deferred to irq_work. Unless
398 * we interrupted irqs-masked code, we can do that now.
401 if (return_to_irqs_enabled) {
402 local_daif_restore(DAIF_PROCCTX_NOIRQ);
407 pr_warn_ratelimited("APEI work queued but not completed");
412 local_daif_restore(current_flags);
417 void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
419 memblock_mark_nomap(addr, size);