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 35 int acpi_noirq = 1; /* skip ACPI IRQ initialization */ 36 int acpi_disabled = 1; 37 EXPORT_SYMBOL(acpi_disabled); 38 39 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ 40 EXPORT_SYMBOL(acpi_pci_disabled); 41 42 static bool param_acpi_off __initdata; 43 static bool param_acpi_on __initdata; 44 static bool param_acpi_force __initdata; 45 46 static 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 } 63 early_param("acpi", parse_acpi); 64 65 static 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 */ 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 && 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 } 230 231 done: 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 } 241 242 static pgprot_t __acpi_get_writethrough_mem_attribute(void) 243 { 244 /* 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. 249 */ 250 pr_warn_once("No MAIR allocation for EFI_MEMORY_WT; treating as Normal Non-cacheable\n"); 251 return __pgprot(PROT_NORMAL_NC); 252 } 253 254 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr) 255 { 256 /* 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. 262 */ 263 264 u64 attr; 265 266 attr = efi_mem_attributes(addr); 267 if (attr & EFI_MEMORY_WB) 268 return PAGE_KERNEL; 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); 274 } 275 276 void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) 277 { 278 efi_memory_desc_t *md, *region = NULL; 279 pgprot_t prot; 280 281 if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP))) 282 return NULL; 283 284 for_each_efi_memory_desc(md) { 285 u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT); 286 287 if (phys < md->phys_addr || phys >= end) 288 continue; 289 290 if (phys + size > end) { 291 pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n"); 292 return NULL; 293 } 294 region = md; 295 break; 296 } 297 298 /* 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. 303 */ 304 prot = __pgprot(PROT_DEVICE_nGnRnE); 305 if (region) { 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); 316 return NULL; 317 } 318 /* 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. 326 */ 327 fallthrough; 328 329 case EFI_RUNTIME_SERVICES_CODE: 330 /* 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. 334 */ 335 prot = PAGE_KERNEL_RO; 336 break; 337 338 case EFI_ACPI_RECLAIM_MEMORY: 339 /* 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 346 * mapping. 347 */ 348 if (memblock_is_map_memory(phys)) 349 return (void __iomem *)__phys_to_virt(phys); 350 fallthrough; 351 352 default: 353 if (region->attribute & EFI_MEMORY_WB) 354 prot = PAGE_KERNEL; 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(); 359 } 360 } 361 return __ioremap(phys, size, prot); 362 } 363 364 /* 365 * Claim Synchronous External Aborts as a firmware first notification. 366 * 367 * Used by KVM and the arch do_sea handler. 368 * @regs may be NULL when called from process context. 369 */ 370 int apei_claim_sea(struct pt_regs *regs) 371 { 372 int err = -ENOENT; 373 bool return_to_irqs_enabled; 374 unsigned long current_flags; 375 376 if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES)) 377 return err; 378 379 current_flags = local_daif_save_flags(); 380 381 /* 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()); 383 384 if (regs) 385 return_to_irqs_enabled = interrupts_enabled(regs); 386 387 /* 388 * SEA can interrupt SError, mask it and describe this as an NMI so 389 * that APEI defers the handling. 390 */ 391 local_daif_restore(DAIF_ERRCTX); 392 nmi_enter(); 393 err = ghes_notify_sea(); 394 nmi_exit(); 395 396 /* 397 * APEI NMI-like notifications are deferred to irq_work. Unless 398 * we interrupted irqs-masked code, we can do that now. 399 */ 400 if (!err) { 401 if (return_to_irqs_enabled) { 402 local_daif_restore(DAIF_PROCCTX_NOIRQ); 403 __irq_enter(); 404 irq_work_run(); 405 __irq_exit(); 406 } else { 407 pr_warn_ratelimited("APEI work queued but not completed"); 408 err = -EINPROGRESS; 409 } 410 } 411 412 local_daif_restore(current_flags); 413 414 return err; 415 } 416 417 void arch_reserve_mem_area(acpi_physical_address addr, size_t size) 418 { 419 memblock_mark_nomap(addr, size); 420 } 421