arch/arm64/kernel/acpi.c

   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/cpumask.h>
  20 #include <linux/efi.h>
  21 #include <linux/efi-bgrt.h>
  22 #include <linux/init.h>
  23 #include <linux/irq.h>
  24 #include <linux/irqdomain.h>
  25 #include <linux/memblock.h>
  26 #include <linux/of_fdt.h>
  27 #include <linux/smp.h>
  28 #include <linux/serial_core.h>
  29
  30 #include <acpi/ghes.h>
  31 #include <asm/cputype.h>
  32 #include <asm/cpu_ops.h>
  33 #include <asm/daifflags.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/smp_plat.h>
  36
  37 int acpi_noirq = 1;             /* skip ACPI IRQ initialization */
  38 int acpi_disabled = 1;
  39 EXPORT_SYMBOL(acpi_disabled);
  40
  41 int acpi_pci_disabled = 1;      /* skip ACPI PCI scan and IRQ initialization */
  42 EXPORT_SYMBOL(acpi_pci_disabled);
  43
  44 static bool param_acpi_off __initdata;
  45 static bool param_acpi_on __initdata;
  46 static bool param_acpi_force __initdata;
  47
  48 static int __init parse_acpi(char *arg)
  49 {
  50         if (!arg)
  51                 return -EINVAL;
  52
  53         /* "acpi=off" disables both ACPI table parsing and interpreter */
  54         if (strcmp(arg, "off") == 0)
  55                 param_acpi_off = true;
  56         else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
  57                 param_acpi_on = true;
  58         else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
  59                 param_acpi_force = true;
  60         else
  61                 return -EINVAL; /* Core will print when we return error */
  62
  63         return 0;
  64 }
  65 early_param("acpi", parse_acpi);
  66
  67 static int __init dt_scan_depth1_nodes(unsigned long node,
  68                                        const char *uname, int depth,
  69                                        void *data)
  70 {
  71         /*
  72          * Ignore anything not directly under the root node; we'll
  73          * catch its parent instead.
  74          */
  75         if (depth != 1)
  76                 return 0;
  77
  78         if (strcmp(uname, "chosen") == 0)
  79                 return 0;
  80
  81         if (strcmp(uname, "hypervisor") == 0 &&
  82             of_flat_dt_is_compatible(node, "xen,xen"))
  83                 return 0;
  84
  85         /*
  86          * This node at depth 1 is neither a chosen node nor a xen node,
  87          * which we do not expect.
  88          */
  89         return 1;
  90 }
  91
  92 /*
  93  * __acpi_map_table() will be called before page_init(), so early_ioremap()
  94  * or early_memremap() should be called here to for ACPI table mapping.
  95  */
  96 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
  97 {
  98         if (!size)
  99                 return NULL;
 100
 101         return early_memremap(phys, size);
 102 }
 103
 104 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
 105 {
 106         if (!map || !size)
 107                 return;
 108
 109         early_memunmap(map, size);
 110 }
 111
 112 bool __init acpi_psci_present(void)
 113 {
 114         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
 115 }
 116
 117 /* Whether HVC must be used instead of SMC as the PSCI conduit */
 118 bool acpi_psci_use_hvc(void)
 119 {
 120         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
 121 }
 122
 123 /*
 124  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
 125  *                            checks on it
 126  *
 127  * Return 0 on success,  <0 on failure
 128  */
 129 static int __init acpi_fadt_sanity_check(void)
 130 {
 131         struct acpi_table_header *table;
 132         struct acpi_table_fadt *fadt;
 133         acpi_status status;
 134         int ret = 0;
 135
 136         /*
 137          * FADT is required on arm64; retrieve it to check its presence
 138          * and carry out revision and ACPI HW reduced compliancy tests
 139          */
 140         status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
 141         if (ACPI_FAILURE(status)) {
 142                 const char *msg = acpi_format_exception(status);
 143
 144                 pr_err("Failed to get FADT table, %s\n", msg);
 145                 return -ENODEV;
 146         }
 147
 148         fadt = (struct acpi_table_fadt *)table;
 149
 150         /*
 151          * Revision in table header is the FADT Major revision, and there
 152          * is a minor revision of FADT which was introduced by ACPI 5.1,
 153          * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
 154          * boot protocol configuration data.
 155          */
 156         if (table->revision < 5 ||
 157            (table->revision == 5 && fadt->minor_revision < 1)) {
 158                 pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n",
 159                        table->revision, fadt->minor_revision);
 160                 ret = -EINVAL;
 161                 goto out;
 162         }
 163
 164         if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
 165                 pr_err("FADT not ACPI hardware reduced compliant\n");
 166                 ret = -EINVAL;
 167         }
 168
 169 out:
 170         /*
 171          * acpi_get_table() creates FADT table mapping that
 172          * should be released after parsing and before resuming boot
 173          */
 174         acpi_put_table(table);
 175         return ret;
 176 }
 177
 178 /*
 179  * acpi_boot_table_init() called from setup_arch(), always.
 180  *      1. find RSDP and get its address, and then find XSDT
 181  *      2. extract all tables and checksums them all
 182  *      3. check ACPI FADT revision
 183  *      4. check ACPI FADT HW reduced flag
 184  *
 185  * We can parse ACPI boot-time tables such as MADT after
 186  * this function is called.
 187  *
 188  * On return ACPI is enabled if either:
 189  *
 190  * - ACPI tables are initialized and sanity checks passed
 191  * - acpi=force was passed in the command line and ACPI was not disabled
 192  *   explicitly through acpi=off command line parameter
 193  *
 194  * ACPI is disabled on function return otherwise
 195  */
 196 void __init acpi_boot_table_init(void)
 197 {
 198         /*
 199          * Enable ACPI instead of device tree unless
 200          * - ACPI has been disabled explicitly (acpi=off), or
 201          * - the device tree is not empty (it has more than just a /chosen node,
 202          *   and a /hypervisor node when running on Xen)
 203          *   and ACPI has not been [force] enabled (acpi=on|force)
 204          */
 205         if (param_acpi_off ||
 206             (!param_acpi_on && !param_acpi_force &&
 207              of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
 208                 goto done;
 209
 210         /*
 211          * ACPI is disabled at this point. Enable it in order to parse
 212          * the ACPI tables and carry out sanity checks
 213          */
 214         enable_acpi();
 215
 216         /*
 217          * If ACPI tables are initialized and FADT sanity checks passed,
 218          * leave ACPI enabled and carry on booting; otherwise disable ACPI
 219          * on initialization error.
 220          * If acpi=force was passed on the command line it forces ACPI
 221          * to be enabled even if its initialization failed.
 222          */
 223         if (acpi_table_init() || acpi_fadt_sanity_check()) {
 224                 pr_err("Failed to init ACPI tables\n");
 225                 if (!param_acpi_force)
 226                         disable_acpi();
 227         }
 228
 229 done:
 230         if (acpi_disabled) {
 231                 if (earlycon_acpi_spcr_enable)
 232                         early_init_dt_scan_chosen_stdout();
 233         } else {
 234                 acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
 235                 if (IS_ENABLED(CONFIG_ACPI_BGRT))
 236                         acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
 237         }
 238 }
 239
 240 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
 241 {
 242         /*
 243          * According to "Table 8 Map: EFI memory types to AArch64 memory
 244          * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
 245          * mapped to a corresponding MAIR attribute encoding.
 246          * The EFI memory attribute advises all possible capabilities
 247          * of a memory region. We use the most efficient capability.
 248          */
 249
 250         u64 attr;
 251
 252         attr = efi_mem_attributes(addr);
 253         if (attr & EFI_MEMORY_WB)
 254                 return PAGE_KERNEL;
 255         if (attr & EFI_MEMORY_WT)
 256                 return __pgprot(PROT_NORMAL_WT);
 257         if (attr & EFI_MEMORY_WC)
 258                 return __pgprot(PROT_NORMAL_NC);
 259         return __pgprot(PROT_DEVICE_nGnRnE);
 260 }
 261
 262 /*
 263  * Claim Synchronous External Aborts as a firmware first notification.
 264  *
 265  * Used by KVM and the arch do_sea handler.
 266  * @regs may be NULL when called from process context.
 267  */
 268 int apei_claim_sea(struct pt_regs *regs)
 269 {
 270         int err = -ENOENT;
 271         unsigned long current_flags;
 272
 273         if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
 274                 return err;
 275
 276         current_flags = arch_local_save_flags();
 277
 278         /*
 279          * SEA can interrupt SError, mask it and describe this as an NMI so
 280          * that APEI defers the handling.
 281          */
 282         local_daif_restore(DAIF_ERRCTX);
 283         nmi_enter();
 284         err = ghes_notify_sea();
 285         nmi_exit();
 286         local_daif_restore(current_flags);
 287
 288         return err;
 289 }