1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * RISC-V 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 * Copyright (C) 2021-2023, Ventana Micro Systems Inc. 13 * Author: Sunil V L <sunilvl@ventanamicro.com> 14 */ 15 16 #include <linux/acpi.h> 17 #include <linux/efi.h> 18 #include <linux/io.h> 19 #include <linux/memblock.h> 20 #include <linux/pci.h> 21 22 int acpi_noirq = 1; /* skip ACPI IRQ initialization */ 23 int acpi_disabled = 1; 24 EXPORT_SYMBOL(acpi_disabled); 25 26 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ 27 EXPORT_SYMBOL(acpi_pci_disabled); 28 29 static bool param_acpi_off __initdata; 30 static bool param_acpi_on __initdata; 31 static bool param_acpi_force __initdata; 32 33 static struct acpi_madt_rintc cpu_madt_rintc[NR_CPUS]; 34 35 static int __init parse_acpi(char *arg) 36 { 37 if (!arg) 38 return -EINVAL; 39 40 /* "acpi=off" disables both ACPI table parsing and interpreter */ 41 if (strcmp(arg, "off") == 0) 42 param_acpi_off = true; 43 else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */ 44 param_acpi_on = true; 45 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */ 46 param_acpi_force = true; 47 else 48 return -EINVAL; /* Core will print when we return error */ 49 50 return 0; 51 } 52 early_param("acpi", parse_acpi); 53 54 /* 55 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity 56 * checks on it 57 * 58 * Return 0 on success, <0 on failure 59 */ 60 static int __init acpi_fadt_sanity_check(void) 61 { 62 struct acpi_table_header *table; 63 struct acpi_table_fadt *fadt; 64 acpi_status status; 65 int ret = 0; 66 67 /* 68 * FADT is required on riscv; retrieve it to check its presence 69 * and carry out revision and ACPI HW reduced compliancy tests 70 */ 71 status = acpi_get_table(ACPI_SIG_FADT, 0, &table); 72 if (ACPI_FAILURE(status)) { 73 const char *msg = acpi_format_exception(status); 74 75 pr_err("Failed to get FADT table, %s\n", msg); 76 return -ENODEV; 77 } 78 79 fadt = (struct acpi_table_fadt *)table; 80 81 /* 82 * The revision in the table header is the FADT's Major revision. The 83 * FADT also has a minor revision, which is stored in the FADT itself. 84 * 85 * TODO: Currently, we check for 6.5 as the minimum version to check 86 * for HW_REDUCED flag. However, once RISC-V updates are released in 87 * the ACPI spec, we need to update this check for exact minor revision 88 */ 89 if (table->revision < 6 || (table->revision == 6 && fadt->minor_revision < 5)) 90 pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 6.5+\n", 91 table->revision, fadt->minor_revision); 92 93 if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) { 94 pr_err("FADT not ACPI hardware reduced compliant\n"); 95 ret = -EINVAL; 96 } 97 98 /* 99 * acpi_get_table() creates FADT table mapping that 100 * should be released after parsing and before resuming boot 101 */ 102 acpi_put_table(table); 103 return ret; 104 } 105 106 /* 107 * acpi_boot_table_init() called from setup_arch(), always. 108 * 1. find RSDP and get its address, and then find XSDT 109 * 2. extract all tables and checksums them all 110 * 3. check ACPI FADT HW reduced flag 111 * 112 * We can parse ACPI boot-time tables such as MADT after 113 * this function is called. 114 * 115 * On return ACPI is enabled if either: 116 * 117 * - ACPI tables are initialized and sanity checks passed 118 * - acpi=force was passed in the command line and ACPI was not disabled 119 * explicitly through acpi=off command line parameter 120 * 121 * ACPI is disabled on function return otherwise 122 */ 123 void __init acpi_boot_table_init(void) 124 { 125 /* 126 * Enable ACPI instead of device tree unless 127 * - ACPI has been disabled explicitly (acpi=off), or 128 * - firmware has not populated ACPI ptr in EFI system table 129 * and ACPI has not been [force] enabled (acpi=on|force) 130 */ 131 if (param_acpi_off || 132 (!param_acpi_on && !param_acpi_force && 133 efi.acpi20 == EFI_INVALID_TABLE_ADDR)) 134 return; 135 136 /* 137 * ACPI is disabled at this point. Enable it in order to parse 138 * the ACPI tables and carry out sanity checks 139 */ 140 enable_acpi(); 141 142 /* 143 * If ACPI tables are initialized and FADT sanity checks passed, 144 * leave ACPI enabled and carry on booting; otherwise disable ACPI 145 * on initialization error. 146 * If acpi=force was passed on the command line it forces ACPI 147 * to be enabled even if its initialization failed. 148 */ 149 if (acpi_table_init() || acpi_fadt_sanity_check()) { 150 pr_err("Failed to init ACPI tables\n"); 151 if (!param_acpi_force) 152 disable_acpi(); 153 } 154 } 155 156 static int acpi_parse_madt_rintc(union acpi_subtable_headers *header, const unsigned long end) 157 { 158 struct acpi_madt_rintc *rintc = (struct acpi_madt_rintc *)header; 159 int cpuid; 160 161 if (!(rintc->flags & ACPI_MADT_ENABLED)) 162 return 0; 163 164 cpuid = riscv_hartid_to_cpuid(rintc->hart_id); 165 /* 166 * When CONFIG_SMP is disabled, mapping won't be created for 167 * all cpus. 168 * CPUs more than num_possible_cpus, will be ignored. 169 */ 170 if (cpuid >= 0 && cpuid < num_possible_cpus()) 171 cpu_madt_rintc[cpuid] = *rintc; 172 173 return 0; 174 } 175 176 /* 177 * Instead of parsing (and freeing) the ACPI table, cache 178 * the RINTC structures since they are frequently used 179 * like in cpuinfo. 180 */ 181 void __init acpi_init_rintc_map(void) 182 { 183 if (acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, acpi_parse_madt_rintc, 0) <= 0) { 184 pr_err("No valid RINTC entries exist\n"); 185 BUG(); 186 } 187 } 188 189 struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu) 190 { 191 return &cpu_madt_rintc[cpu]; 192 } 193 194 /* 195 * __acpi_map_table() will be called before paging_init(), so early_ioremap() 196 * or early_memremap() should be called here to for ACPI table mapping. 197 */ 198 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size) 199 { 200 if (!size) 201 return NULL; 202 203 return early_ioremap(phys, size); 204 } 205 206 void __init __acpi_unmap_table(void __iomem *map, unsigned long size) 207 { 208 if (!map || !size) 209 return; 210 211 early_iounmap(map, size); 212 } 213 214 void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) 215 { 216 efi_memory_desc_t *md, *region = NULL; 217 pgprot_t prot; 218 219 if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP))) 220 return NULL; 221 222 for_each_efi_memory_desc(md) { 223 u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT); 224 225 if (phys < md->phys_addr || phys >= end) 226 continue; 227 228 if (phys + size > end) { 229 pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n"); 230 return NULL; 231 } 232 region = md; 233 break; 234 } 235 236 /* 237 * It is fine for AML to remap regions that are not represented in the 238 * EFI memory map at all, as it only describes normal memory, and MMIO 239 * regions that require a virtual mapping to make them accessible to 240 * the EFI runtime services. 241 */ 242 prot = PAGE_KERNEL_IO; 243 if (region) { 244 switch (region->type) { 245 case EFI_LOADER_CODE: 246 case EFI_LOADER_DATA: 247 case EFI_BOOT_SERVICES_CODE: 248 case EFI_BOOT_SERVICES_DATA: 249 case EFI_CONVENTIONAL_MEMORY: 250 case EFI_PERSISTENT_MEMORY: 251 if (memblock_is_map_memory(phys) || 252 !memblock_is_region_memory(phys, size)) { 253 pr_warn(FW_BUG "requested region covers kernel memory\n"); 254 return NULL; 255 } 256 257 /* 258 * Mapping kernel memory is permitted if the region in 259 * question is covered by a single memblock with the 260 * NOMAP attribute set: this enables the use of ACPI 261 * table overrides passed via initramfs. 262 * This particular use case only requires read access. 263 */ 264 fallthrough; 265 266 case EFI_RUNTIME_SERVICES_CODE: 267 /* 268 * This would be unusual, but not problematic per se, 269 * as long as we take care not to create a writable 270 * mapping for executable code. 271 */ 272 prot = PAGE_KERNEL_RO; 273 break; 274 275 case EFI_ACPI_RECLAIM_MEMORY: 276 /* 277 * ACPI reclaim memory is used to pass firmware tables 278 * and other data that is intended for consumption by 279 * the OS only, which may decide it wants to reclaim 280 * that memory and use it for something else. We never 281 * do that, but we usually add it to the linear map 282 * anyway, in which case we should use the existing 283 * mapping. 284 */ 285 if (memblock_is_map_memory(phys)) 286 return (void __iomem *)__va(phys); 287 fallthrough; 288 289 default: 290 if (region->attribute & EFI_MEMORY_WB) 291 prot = PAGE_KERNEL; 292 else if ((region->attribute & EFI_MEMORY_WC) || 293 (region->attribute & EFI_MEMORY_WT)) 294 prot = pgprot_writecombine(PAGE_KERNEL); 295 } 296 } 297 298 return ioremap_prot(phys, size, pgprot_val(prot)); 299 } 300 301 #ifdef CONFIG_PCI 302 303 /* 304 * These interfaces are defined just to enable building ACPI core. 305 * TODO: Update it with actual implementation when external interrupt 306 * controller support is added in RISC-V ACPI. 307 */ 308 int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn, 309 int reg, int len, u32 *val) 310 { 311 return PCIBIOS_DEVICE_NOT_FOUND; 312 } 313 314 int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn, 315 int reg, int len, u32 val) 316 { 317 return PCIBIOS_DEVICE_NOT_FOUND; 318 } 319 320 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus) 321 { 322 return -1; 323 } 324 325 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) 326 { 327 return NULL; 328 } 329 #endif /* CONFIG_PCI */ 330