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/efi.h> 22 #include <linux/efi-bgrt.h> 23 #include <linux/init.h> 24 #include <linux/irq.h> 25 #include <linux/irqdomain.h> 26 #include <linux/memblock.h> 27 #include <linux/of_fdt.h> 28 #include <linux/smp.h> 29 #include <linux/serial_core.h> 30 31 #include <asm/cputype.h> 32 #include <asm/cpu_ops.h> 33 #include <asm/pgtable.h> 34 #include <asm/smp_plat.h> 35 36 int acpi_noirq = 1; /* skip ACPI IRQ initialization */ 37 int acpi_disabled = 1; 38 EXPORT_SYMBOL(acpi_disabled); 39 40 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ 41 EXPORT_SYMBOL(acpi_pci_disabled); 42 43 static bool param_acpi_off __initdata; 44 static bool param_acpi_on __initdata; 45 static bool param_acpi_force __initdata; 46 47 static int __init parse_acpi(char *arg) 48 { 49 if (!arg) 50 return -EINVAL; 51 52 /* "acpi=off" disables both ACPI table parsing and interpreter */ 53 if (strcmp(arg, "off") == 0) 54 param_acpi_off = true; 55 else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */ 56 param_acpi_on = true; 57 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */ 58 param_acpi_force = true; 59 else 60 return -EINVAL; /* Core will print when we return error */ 61 62 return 0; 63 } 64 early_param("acpi", parse_acpi); 65 66 static int __init dt_scan_depth1_nodes(unsigned long node, 67 const char *uname, int depth, 68 void *data) 69 { 70 /* 71 * Ignore anything not directly under the root node; we'll 72 * catch its parent instead. 73 */ 74 if (depth != 1) 75 return 0; 76 77 if (strcmp(uname, "chosen") == 0) 78 return 0; 79 80 if (strcmp(uname, "hypervisor") == 0 && 81 of_flat_dt_is_compatible(node, "xen,xen")) 82 return 0; 83 84 /* 85 * This node at depth 1 is neither a chosen node nor a xen node, 86 * which we do not expect. 87 */ 88 return 1; 89 } 90 91 /* 92 * __acpi_map_table() will be called before page_init(), so early_ioremap() 93 * or early_memremap() should be called here to for ACPI table mapping. 94 */ 95 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size) 96 { 97 if (!size) 98 return NULL; 99 100 return early_memremap(phys, size); 101 } 102 103 void __init __acpi_unmap_table(void __iomem *map, unsigned long size) 104 { 105 if (!map || !size) 106 return; 107 108 early_memunmap(map, size); 109 } 110 111 bool __init acpi_psci_present(void) 112 { 113 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT; 114 } 115 116 /* Whether HVC must be used instead of SMC as the PSCI conduit */ 117 bool acpi_psci_use_hvc(void) 118 { 119 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC; 120 } 121 122 /* 123 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity 124 * checks on it 125 * 126 * Return 0 on success, <0 on failure 127 */ 128 static int __init acpi_fadt_sanity_check(void) 129 { 130 struct acpi_table_header *table; 131 struct acpi_table_fadt *fadt; 132 acpi_status status; 133 int ret = 0; 134 135 /* 136 * FADT is required on arm64; retrieve it to check its presence 137 * and carry out revision and ACPI HW reduced compliancy tests 138 */ 139 status = acpi_get_table(ACPI_SIG_FADT, 0, &table); 140 if (ACPI_FAILURE(status)) { 141 const char *msg = acpi_format_exception(status); 142 143 pr_err("Failed to get FADT table, %s\n", msg); 144 return -ENODEV; 145 } 146 147 fadt = (struct acpi_table_fadt *)table; 148 149 /* 150 * Revision in table header is the FADT Major revision, and there 151 * is a minor revision of FADT which was introduced by ACPI 5.1, 152 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP 153 * boot protocol configuration data. 154 */ 155 if (table->revision < 5 || 156 (table->revision == 5 && fadt->minor_revision < 1)) { 157 pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n", 158 table->revision, fadt->minor_revision); 159 ret = -EINVAL; 160 goto out; 161 } 162 163 if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) { 164 pr_err("FADT not ACPI hardware reduced compliant\n"); 165 ret = -EINVAL; 166 } 167 168 out: 169 /* 170 * acpi_get_table() creates FADT table mapping that 171 * should be released after parsing and before resuming boot 172 */ 173 acpi_put_table(table); 174 return ret; 175 } 176 177 /* 178 * acpi_boot_table_init() called from setup_arch(), always. 179 * 1. find RSDP and get its address, and then find XSDT 180 * 2. extract all tables and checksums them all 181 * 3. check ACPI FADT revision 182 * 4. check ACPI FADT HW reduced flag 183 * 184 * We can parse ACPI boot-time tables such as MADT after 185 * this function is called. 186 * 187 * On return ACPI is enabled if either: 188 * 189 * - ACPI tables are initialized and sanity checks passed 190 * - acpi=force was passed in the command line and ACPI was not disabled 191 * explicitly through acpi=off command line parameter 192 * 193 * ACPI is disabled on function return otherwise 194 */ 195 void __init acpi_boot_table_init(void) 196 { 197 /* 198 * Enable ACPI instead of device tree unless 199 * - ACPI has been disabled explicitly (acpi=off), or 200 * - the device tree is not empty (it has more than just a /chosen node, 201 * and a /hypervisor node when running on Xen) 202 * and ACPI has not been [force] enabled (acpi=on|force) 203 */ 204 if (param_acpi_off || 205 (!param_acpi_on && !param_acpi_force && 206 of_scan_flat_dt(dt_scan_depth1_nodes, NULL))) 207 goto done; 208 209 /* 210 * ACPI is disabled at this point. Enable it in order to parse 211 * the ACPI tables and carry out sanity checks 212 */ 213 enable_acpi(); 214 215 /* 216 * If ACPI tables are initialized and FADT sanity checks passed, 217 * leave ACPI enabled and carry on booting; otherwise disable ACPI 218 * on initialization error. 219 * If acpi=force was passed on the command line it forces ACPI 220 * to be enabled even if its initialization failed. 221 */ 222 if (acpi_table_init() || acpi_fadt_sanity_check()) { 223 pr_err("Failed to init ACPI tables\n"); 224 if (!param_acpi_force) 225 disable_acpi(); 226 } 227 228 done: 229 if (acpi_disabled) { 230 if (earlycon_acpi_spcr_enable) 231 early_init_dt_scan_chosen_stdout(); 232 } else { 233 acpi_parse_spcr(earlycon_acpi_spcr_enable, true); 234 if (IS_ENABLED(CONFIG_ACPI_BGRT)) 235 acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt); 236 } 237 } 238 239 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr) 240 { 241 /* 242 * According to "Table 8 Map: EFI memory types to AArch64 memory 243 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is 244 * mapped to a corresponding MAIR attribute encoding. 245 * The EFI memory attribute advises all possible capabilities 246 * of a memory region. We use the most efficient capability. 247 */ 248 249 u64 attr; 250 251 attr = efi_mem_attributes(addr); 252 if (attr & EFI_MEMORY_WB) 253 return PAGE_KERNEL; 254 if (attr & EFI_MEMORY_WT) 255 return __pgprot(PROT_NORMAL_WT); 256 if (attr & EFI_MEMORY_WC) 257 return __pgprot(PROT_NORMAL_NC); 258 return __pgprot(PROT_DEVICE_nGnRnE); 259 } 260