1 /* 2 * ARM64 Specific Low-Level ACPI Boot Support 3 * 4 * Copyright (C) 2013-2014, Linaro Ltd. 5 * Author: Al Stone <al.stone@linaro.org> 6 * Author: Graeme Gregory <graeme.gregory@linaro.org> 7 * Author: Hanjun Guo <hanjun.guo@linaro.org> 8 * Author: Tomasz Nowicki <tomasz.nowicki@linaro.org> 9 * Author: Naresh Bhat <naresh.bhat@linaro.org> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15 16 #define pr_fmt(fmt) "ACPI: " fmt 17 18 #include <linux/acpi.h> 19 #include <linux/bootmem.h> 20 #include <linux/cpumask.h> 21 #include <linux/init.h> 22 #include <linux/irq.h> 23 #include <linux/irqdomain.h> 24 #include <linux/memblock.h> 25 #include <linux/of_fdt.h> 26 #include <linux/smp.h> 27 #include <linux/serial_core.h> 28 29 #include <asm/cputype.h> 30 #include <asm/cpu_ops.h> 31 #include <asm/smp_plat.h> 32 33 #ifdef CONFIG_ACPI_APEI 34 # include <linux/efi.h> 35 # include <asm/pgtable.h> 36 #endif 37 38 int acpi_noirq = 1; /* skip ACPI IRQ initialization */ 39 int acpi_disabled = 1; 40 EXPORT_SYMBOL(acpi_disabled); 41 42 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ 43 EXPORT_SYMBOL(acpi_pci_disabled); 44 45 static bool param_acpi_off __initdata; 46 static bool param_acpi_on __initdata; 47 static bool param_acpi_force __initdata; 48 49 static int __init parse_acpi(char *arg) 50 { 51 if (!arg) 52 return -EINVAL; 53 54 /* "acpi=off" disables both ACPI table parsing and interpreter */ 55 if (strcmp(arg, "off") == 0) 56 param_acpi_off = true; 57 else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */ 58 param_acpi_on = true; 59 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */ 60 param_acpi_force = true; 61 else 62 return -EINVAL; /* Core will print when we return error */ 63 64 return 0; 65 } 66 early_param("acpi", parse_acpi); 67 68 static int __init dt_scan_depth1_nodes(unsigned long node, 69 const char *uname, int depth, 70 void *data) 71 { 72 /* 73 * Ignore anything not directly under the root node; we'll 74 * catch its parent instead. 75 */ 76 if (depth != 1) 77 return 0; 78 79 if (strcmp(uname, "chosen") == 0) 80 return 0; 81 82 if (strcmp(uname, "hypervisor") == 0 && 83 of_flat_dt_is_compatible(node, "xen,xen")) 84 return 0; 85 86 /* 87 * This node at depth 1 is neither a chosen node nor a xen node, 88 * which we do not expect. 89 */ 90 return 1; 91 } 92 93 /* 94 * __acpi_map_table() will be called before page_init(), so early_ioremap() 95 * or early_memremap() should be called here to for ACPI table mapping. 96 */ 97 char *__init __acpi_map_table(unsigned long phys, unsigned long size) 98 { 99 if (!size) 100 return NULL; 101 102 return early_memremap(phys, size); 103 } 104 105 void __init __acpi_unmap_table(char *map, unsigned long size) 106 { 107 if (!map || !size) 108 return; 109 110 early_memunmap(map, size); 111 } 112 113 bool __init acpi_psci_present(void) 114 { 115 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT; 116 } 117 118 /* Whether HVC must be used instead of SMC as the PSCI conduit */ 119 bool __init acpi_psci_use_hvc(void) 120 { 121 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC; 122 } 123 124 /* 125 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity 126 * checks on it 127 * 128 * Return 0 on success, <0 on failure 129 */ 130 static int __init acpi_fadt_sanity_check(void) 131 { 132 struct acpi_table_header *table; 133 struct acpi_table_fadt *fadt; 134 acpi_status status; 135 acpi_size tbl_size; 136 int ret = 0; 137 138 /* 139 * FADT is required on arm64; retrieve it to check its presence 140 * and carry out revision and ACPI HW reduced compliancy tests 141 */ 142 status = acpi_get_table_with_size(ACPI_SIG_FADT, 0, &table, &tbl_size); 143 if (ACPI_FAILURE(status)) { 144 const char *msg = acpi_format_exception(status); 145 146 pr_err("Failed to get FADT table, %s\n", msg); 147 return -ENODEV; 148 } 149 150 fadt = (struct acpi_table_fadt *)table; 151 152 /* 153 * Revision in table header is the FADT Major revision, and there 154 * is a minor revision of FADT which was introduced by ACPI 5.1, 155 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP 156 * boot protocol configuration data. 157 */ 158 if (table->revision < 5 || 159 (table->revision == 5 && fadt->minor_revision < 1)) { 160 pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n", 161 table->revision, fadt->minor_revision); 162 ret = -EINVAL; 163 goto out; 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_with_size() creates FADT table mapping that 174 * should be released after parsing and before resuming boot 175 */ 176 early_acpi_os_unmap_memory(table, tbl_size); 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_init_is_deferred) 234 early_init_dt_scan_chosen_stdout(); 235 } else { 236 parse_spcr(earlycon_init_is_deferred); 237 } 238 } 239 240 #ifdef CONFIG_ACPI_APEI 241 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr) 242 { 243 /* 244 * According to "Table 8 Map: EFI memory types to AArch64 memory 245 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is 246 * mapped to a corresponding MAIR attribute encoding. 247 * The EFI memory attribute advises all possible capabilities 248 * of a memory region. We use the most efficient capability. 249 */ 250 251 u64 attr; 252 253 attr = efi_mem_attributes(addr); 254 if (attr & EFI_MEMORY_WB) 255 return PAGE_KERNEL; 256 if (attr & EFI_MEMORY_WT) 257 return __pgprot(PROT_NORMAL_WT); 258 if (attr & EFI_MEMORY_WC) 259 return __pgprot(PROT_NORMAL_NC); 260 return __pgprot(PROT_DEVICE_nGnRnE); 261 } 262 #endif 263