arch/arm64/kernel/acpi.c

   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/memblock.h>
  23 #include <linux/of_fdt.h>
  24 #include <linux/smp.h>
  25 #include <linux/serial_core.h>
  26
  27 #include <acpi/ghes.h>
  28 #include <asm/cputype.h>
  29 #include <asm/cpu_ops.h>
  30 #include <asm/daifflags.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/smp_plat.h>
  33
  34 int acpi_noirq = 1;             /* skip ACPI IRQ initialization */
  35 int acpi_disabled = 1;
  36 EXPORT_SYMBOL(acpi_disabled);
  37
  38 int acpi_pci_disabled = 1;      /* skip ACPI PCI scan and IRQ initialization */
  39 EXPORT_SYMBOL(acpi_pci_disabled);
  40
  41 static bool param_acpi_off __initdata;
  42 static bool param_acpi_on __initdata;
  43 static bool param_acpi_force __initdata;
  44
  45 static int __init parse_acpi(char *arg)
  46 {
  47         if (!arg)
  48                 return -EINVAL;
  49
  50         /* "acpi=off" disables both ACPI table parsing and interpreter */
  51         if (strcmp(arg, "off") == 0)
  52                 param_acpi_off = true;
  53         else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
  54                 param_acpi_on = true;
  55         else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
  56                 param_acpi_force = true;
  57         else
  58                 return -EINVAL; /* Core will print when we return error */
  59
  60         return 0;
  61 }
  62 early_param("acpi", parse_acpi);
  63
  64 static int __init dt_scan_depth1_nodes(unsigned long node,
  65                                        const char *uname, int depth,
  66                                        void *data)
  67 {
  68         /*
  69          * Ignore anything not directly under the root node; we'll
  70          * catch its parent instead.
  71          */
  72         if (depth != 1)
  73                 return 0;
  74
  75         if (strcmp(uname, "chosen") == 0)
  76                 return 0;
  77
  78         if (strcmp(uname, "hypervisor") == 0 &&
  79             of_flat_dt_is_compatible(node, "xen,xen"))
  80                 return 0;
  81
  82         /*
  83          * This node at depth 1 is neither a chosen node nor a xen node,
  84          * which we do not expect.
  85          */
  86         return 1;
  87 }
  88
  89 /*
  90  * __acpi_map_table() will be called before page_init(), so early_ioremap()
  91  * or early_memremap() should be called here to for ACPI table mapping.
  92  */
  93 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
  94 {
  95         if (!size)
  96                 return NULL;
  97
  98         return early_memremap(phys, size);
  99 }
 100
 101 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
 102 {
 103         if (!map || !size)
 104                 return;
 105
 106         early_memunmap(map, size);
 107 }
 108
 109 bool __init acpi_psci_present(void)
 110 {
 111         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
 112 }
 113
 114 /* Whether HVC must be used instead of SMC as the PSCI conduit */
 115 bool acpi_psci_use_hvc(void)
 116 {
 117         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
 118 }
 119
 120 /*
 121  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
 122  *                            checks on it
 123  *
 124  * Return 0 on success,  <0 on failure
 125  */
 126 static int __init acpi_fadt_sanity_check(void)
 127 {
 128         struct acpi_table_header *table;
 129         struct acpi_table_fadt *fadt;
 130         acpi_status status;
 131         int ret = 0;
 132
 133         /*
 134          * FADT is required on arm64; retrieve it to check its presence
 135          * and carry out revision and ACPI HW reduced compliancy tests
 136          */
 137         status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
 138         if (ACPI_FAILURE(status)) {
 139                 const char *msg = acpi_format_exception(status);
 140
 141                 pr_err("Failed to get FADT table, %s\n", msg);
 142                 return -ENODEV;
 143         }
 144
 145         fadt = (struct acpi_table_fadt *)table;
 146
 147         /*
 148          * Revision in table header is the FADT Major revision, and there
 149          * is a minor revision of FADT which was introduced by ACPI 5.1,
 150          * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
 151          * boot protocol configuration data.
 152          */
 153         if (table->revision < 5 ||
 154            (table->revision == 5 && fadt->minor_revision < 1)) {
 155                 pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 5.1+\n",
 156                        table->revision, fadt->minor_revision);
 157
 158                 if (!fadt->arm_boot_flags) {
 159                         ret = -EINVAL;
 160                         goto out;
 161                 }
 162                 pr_err("FADT has ARM boot flags set, assuming 5.1\n");
 163         }
 164
 165         if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
 166                 pr_err("FADT not ACPI hardware reduced compliant\n");
 167                 ret = -EINVAL;
 168         }
 169
 170 out:
 171         /*
 172          * acpi_get_table() creates FADT table mapping that
 173          * should be released after parsing and before resuming boot
 174          */
 175         acpi_put_table(table);
 176         return ret;
 177 }
 178
 179 /*
 180  * acpi_boot_table_init() called from setup_arch(), always.
 181  *      1. find RSDP and get its address, and then find XSDT
 182  *      2. extract all tables and checksums them all
 183  *      3. check ACPI FADT revision
 184  *      4. check ACPI FADT HW reduced flag
 185  *
 186  * We can parse ACPI boot-time tables such as MADT after
 187  * this function is called.
 188  *
 189  * On return ACPI is enabled if either:
 190  *
 191  * - ACPI tables are initialized and sanity checks passed
 192  * - acpi=force was passed in the command line and ACPI was not disabled
 193  *   explicitly through acpi=off command line parameter
 194  *
 195  * ACPI is disabled on function return otherwise
 196  */
 197 void __init acpi_boot_table_init(void)
 198 {
 199         /*
 200          * Enable ACPI instead of device tree unless
 201          * - ACPI has been disabled explicitly (acpi=off), or
 202          * - the device tree is not empty (it has more than just a /chosen node,
 203          *   and a /hypervisor node when running on Xen)
 204          *   and ACPI has not been [force] enabled (acpi=on|force)
 205          */
 206         if (param_acpi_off ||
 207             (!param_acpi_on && !param_acpi_force &&
 208              of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
 209                 goto done;
 210
 211         /*
 212          * ACPI is disabled at this point. Enable it in order to parse
 213          * the ACPI tables and carry out sanity checks
 214          */
 215         enable_acpi();
 216
 217         /*
 218          * If ACPI tables are initialized and FADT sanity checks passed,
 219          * leave ACPI enabled and carry on booting; otherwise disable ACPI
 220          * on initialization error.
 221          * If acpi=force was passed on the command line it forces ACPI
 222          * to be enabled even if its initialization failed.
 223          */
 224         if (acpi_table_init() || acpi_fadt_sanity_check()) {
 225                 pr_err("Failed to init ACPI tables\n");
 226                 if (!param_acpi_force)
 227                         disable_acpi();
 228         }
 229
 230 done:
 231         if (acpi_disabled) {
 232                 if (earlycon_acpi_spcr_enable)
 233                         early_init_dt_scan_chosen_stdout();
 234         } else {
 235                 acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
 236                 if (IS_ENABLED(CONFIG_ACPI_BGRT))
 237                         acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
 238         }
 239 }
 240
 241 pgprot_t __acpi_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
 263 /*
 264  * Claim Synchronous External Aborts as a firmware first notification.
 265  *
 266  * Used by KVM and the arch do_sea handler.
 267  * @regs may be NULL when called from process context.
 268  */
 269 int apei_claim_sea(struct pt_regs *regs)
 270 {
 271         int err = -ENOENT;
 272         unsigned long current_flags;
 273
 274         if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
 275                 return err;
 276
 277         current_flags = local_daif_save_flags();
 278
 279         /*
 280          * SEA can interrupt SError, mask it and describe this as an NMI so
 281          * that APEI defers the handling.
 282          */
 283         local_daif_restore(DAIF_ERRCTX);
 284         nmi_enter();
 285         err = ghes_notify_sea();
 286         nmi_exit();
 287         local_daif_restore(current_flags);
 288
 289         return err;
 290 }