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/of_fdt.h> 21 #include <linux/pci.h> 22 #include <linux/serial_core.h> 23 24 int acpi_noirq = 1; /* skip ACPI IRQ initialization */ 25 int acpi_disabled = 1; 26 EXPORT_SYMBOL(acpi_disabled); 27 28 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ 29 EXPORT_SYMBOL(acpi_pci_disabled); 30 31 static bool param_acpi_off __initdata; 32 static bool param_acpi_on __initdata; 33 static bool param_acpi_force __initdata; 34 35 static struct acpi_madt_rintc cpu_madt_rintc[NR_CPUS]; 36 37 static int __init parse_acpi(char *arg) 38 { 39 if (!arg) 40 return -EINVAL; 41 42 /* "acpi=off" disables both ACPI table parsing and interpreter */ 43 if (strcmp(arg, "off") == 0) 44 param_acpi_off = true; 45 else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */ 46 param_acpi_on = true; 47 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */ 48 param_acpi_force = true; 49 else 50 return -EINVAL; /* Core will print when we return error */ 51 52 return 0; 53 } 54 early_param("acpi", parse_acpi); 55 56 /* 57 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity 58 * checks on it 59 * 60 * Return 0 on success, <0 on failure 61 */ 62 static int __init acpi_fadt_sanity_check(void) 63 { 64 struct acpi_table_header *table; 65 struct acpi_table_fadt *fadt; 66 acpi_status status; 67 int ret = 0; 68 69 /* 70 * FADT is required on riscv; retrieve it to check its presence 71 * and carry out revision and ACPI HW reduced compliancy tests 72 */ 73 status = acpi_get_table(ACPI_SIG_FADT, 0, &table); 74 if (ACPI_FAILURE(status)) { 75 const char *msg = acpi_format_exception(status); 76 77 pr_err("Failed to get FADT table, %s\n", msg); 78 return -ENODEV; 79 } 80 81 fadt = (struct acpi_table_fadt *)table; 82 83 /* 84 * The revision in the table header is the FADT's Major revision. The 85 * FADT also has a minor revision, which is stored in the FADT itself. 86 * 87 * TODO: Currently, we check for 6.5 as the minimum version to check 88 * for HW_REDUCED flag. However, once RISC-V updates are released in 89 * the ACPI spec, we need to update this check for exact minor revision 90 */ 91 if (table->revision < 6 || (table->revision == 6 && fadt->minor_revision < 5)) 92 pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 6.5+\n", 93 table->revision, fadt->minor_revision); 94 95 if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) { 96 pr_err("FADT not ACPI hardware reduced compliant\n"); 97 ret = -EINVAL; 98 } 99 100 /* 101 * acpi_get_table() creates FADT table mapping that 102 * should be released after parsing and before resuming boot 103 */ 104 acpi_put_table(table); 105 return ret; 106 } 107 108 /* 109 * acpi_boot_table_init() called from setup_arch(), always. 110 * 1. find RSDP and get its address, and then find XSDT 111 * 2. extract all tables and checksums them all 112 * 3. check ACPI FADT HW reduced flag 113 * 114 * We can parse ACPI boot-time tables such as MADT after 115 * this function is called. 116 * 117 * On return ACPI is enabled if either: 118 * 119 * - ACPI tables are initialized and sanity checks passed 120 * - acpi=force was passed in the command line and ACPI was not disabled 121 * explicitly through acpi=off command line parameter 122 * 123 * ACPI is disabled on function return otherwise 124 */ 125 void __init acpi_boot_table_init(void) 126 { 127 /* 128 * Enable ACPI instead of device tree unless 129 * - ACPI has been disabled explicitly (acpi=off), or 130 * - firmware has not populated ACPI ptr in EFI system table 131 * and ACPI has not been [force] enabled (acpi=on|force) 132 */ 133 if (param_acpi_off || 134 (!param_acpi_on && !param_acpi_force && 135 efi.acpi20 == EFI_INVALID_TABLE_ADDR)) 136 goto done; 137 138 /* 139 * ACPI is disabled at this point. Enable it in order to parse 140 * the ACPI tables and carry out sanity checks 141 */ 142 enable_acpi(); 143 144 /* 145 * If ACPI tables are initialized and FADT sanity checks passed, 146 * leave ACPI enabled and carry on booting; otherwise disable ACPI 147 * on initialization error. 148 * If acpi=force was passed on the command line it forces ACPI 149 * to be enabled even if its initialization failed. 150 */ 151 if (acpi_table_init() || acpi_fadt_sanity_check()) { 152 pr_err("Failed to init ACPI tables\n"); 153 if (!param_acpi_force) 154 disable_acpi(); 155 } 156 157 done: 158 if (acpi_disabled) { 159 if (earlycon_acpi_spcr_enable) 160 early_init_dt_scan_chosen_stdout(); 161 } else { 162 acpi_parse_spcr(earlycon_acpi_spcr_enable, true); 163 } 164 } 165 166 static int acpi_parse_madt_rintc(union acpi_subtable_headers *header, const unsigned long end) 167 { 168 struct acpi_madt_rintc *rintc = (struct acpi_madt_rintc *)header; 169 int cpuid; 170 171 if (!(rintc->flags & ACPI_MADT_ENABLED)) 172 return 0; 173 174 cpuid = riscv_hartid_to_cpuid(rintc->hart_id); 175 /* 176 * When CONFIG_SMP is disabled, mapping won't be created for 177 * all cpus. 178 * CPUs more than num_possible_cpus, will be ignored. 179 */ 180 if (cpuid >= 0 && cpuid < num_possible_cpus()) 181 cpu_madt_rintc[cpuid] = *rintc; 182 183 return 0; 184 } 185 186 /* 187 * Instead of parsing (and freeing) the ACPI table, cache 188 * the RINTC structures since they are frequently used 189 * like in cpuinfo. 190 */ 191 void __init acpi_init_rintc_map(void) 192 { 193 if (acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, acpi_parse_madt_rintc, 0) <= 0) { 194 pr_err("No valid RINTC entries exist\n"); 195 BUG(); 196 } 197 } 198 199 struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu) 200 { 201 return &cpu_madt_rintc[cpu]; 202 } 203 204 /* 205 * __acpi_map_table() will be called before paging_init(), so early_ioremap() 206 * or early_memremap() should be called here to for ACPI table mapping. 207 */ 208 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size) 209 { 210 if (!size) 211 return NULL; 212 213 return early_ioremap(phys, size); 214 } 215 216 void __init __acpi_unmap_table(void __iomem *map, unsigned long size) 217 { 218 if (!map || !size) 219 return; 220 221 early_iounmap(map, size); 222 } 223 224 void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) 225 { 226 efi_memory_desc_t *md, *region = NULL; 227 pgprot_t prot; 228 229 if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP))) 230 return NULL; 231 232 for_each_efi_memory_desc(md) { 233 u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT); 234 235 if (phys < md->phys_addr || phys >= end) 236 continue; 237 238 if (phys + size > end) { 239 pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n"); 240 return NULL; 241 } 242 region = md; 243 break; 244 } 245 246 /* 247 * It is fine for AML to remap regions that are not represented in the 248 * EFI memory map at all, as it only describes normal memory, and MMIO 249 * regions that require a virtual mapping to make them accessible to 250 * the EFI runtime services. 251 */ 252 prot = PAGE_KERNEL_IO; 253 if (region) { 254 switch (region->type) { 255 case EFI_LOADER_CODE: 256 case EFI_LOADER_DATA: 257 case EFI_BOOT_SERVICES_CODE: 258 case EFI_BOOT_SERVICES_DATA: 259 case EFI_CONVENTIONAL_MEMORY: 260 case EFI_PERSISTENT_MEMORY: 261 if (memblock_is_map_memory(phys) || 262 !memblock_is_region_memory(phys, size)) { 263 pr_warn(FW_BUG "requested region covers kernel memory\n"); 264 return NULL; 265 } 266 267 /* 268 * Mapping kernel memory is permitted if the region in 269 * question is covered by a single memblock with the 270 * NOMAP attribute set: this enables the use of ACPI 271 * table overrides passed via initramfs. 272 * This particular use case only requires read access. 273 */ 274 fallthrough; 275 276 case EFI_RUNTIME_SERVICES_CODE: 277 /* 278 * This would be unusual, but not problematic per se, 279 * as long as we take care not to create a writable 280 * mapping for executable code. 281 */ 282 prot = PAGE_KERNEL_RO; 283 break; 284 285 case EFI_ACPI_RECLAIM_MEMORY: 286 /* 287 * ACPI reclaim memory is used to pass firmware tables 288 * and other data that is intended for consumption by 289 * the OS only, which may decide it wants to reclaim 290 * that memory and use it for something else. We never 291 * do that, but we usually add it to the linear map 292 * anyway, in which case we should use the existing 293 * mapping. 294 */ 295 if (memblock_is_map_memory(phys)) 296 return (void __iomem *)__va(phys); 297 fallthrough; 298 299 default: 300 if (region->attribute & EFI_MEMORY_WB) 301 prot = PAGE_KERNEL; 302 else if ((region->attribute & EFI_MEMORY_WC) || 303 (region->attribute & EFI_MEMORY_WT)) 304 prot = pgprot_writecombine(PAGE_KERNEL); 305 } 306 } 307 308 return ioremap_prot(phys, size, pgprot_val(prot)); 309 } 310 311 #ifdef CONFIG_PCI 312 313 /* 314 * raw_pci_read/write - Platform-specific PCI config space access. 315 */ 316 int raw_pci_read(unsigned int domain, unsigned int bus, 317 unsigned int devfn, int reg, int len, u32 *val) 318 { 319 struct pci_bus *b = pci_find_bus(domain, bus); 320 321 if (!b) 322 return PCIBIOS_DEVICE_NOT_FOUND; 323 return b->ops->read(b, devfn, reg, len, val); 324 } 325 326 int raw_pci_write(unsigned int domain, unsigned int bus, 327 unsigned int devfn, int reg, int len, u32 val) 328 { 329 struct pci_bus *b = pci_find_bus(domain, bus); 330 331 if (!b) 332 return PCIBIOS_DEVICE_NOT_FOUND; 333 return b->ops->write(b, devfn, reg, len, val); 334 } 335 336 #endif /* CONFIG_PCI */ 337