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/bootmem.h>
  20 #include <linux/cpumask.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 <asm/cputype.h>
  31 #include <asm/cpu_ops.h>
  32 #include <asm/smp_plat.h>
  33
  34 #ifdef CONFIG_ACPI_APEI
  35 # include <linux/efi.h>
  36 # include <asm/pgtable.h>
  37 #endif
  38
  39 int acpi_noirq = 1;             /* skip ACPI IRQ initialization */
  40 int acpi_disabled = 1;
  41 EXPORT_SYMBOL(acpi_disabled);
  42
  43 int acpi_pci_disabled = 1;      /* skip ACPI PCI scan and IRQ initialization */
  44 EXPORT_SYMBOL(acpi_pci_disabled);
  45
  46 static bool param_acpi_off __initdata;
  47 static bool param_acpi_on __initdata;
  48 static bool param_acpi_force __initdata;
  49
  50 static int __init parse_acpi(char *arg)
  51 {
  52         if (!arg)
  53                 return -EINVAL;
  54
  55         /* "acpi=off" disables both ACPI table parsing and interpreter */
  56         if (strcmp(arg, "off") == 0)
  57                 param_acpi_off = true;
  58         else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
  59                 param_acpi_on = true;
  60         else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
  61                 param_acpi_force = true;
  62         else
  63                 return -EINVAL; /* Core will print when we return error */
  64
  65         return 0;
  66 }
  67 early_param("acpi", parse_acpi);
  68
  69 static int __init dt_scan_depth1_nodes(unsigned long node,
  70                                        const char *uname, int depth,
  71                                        void *data)
  72 {
  73         /*
  74          * Ignore anything not directly under the root node; we'll
  75          * catch its parent instead.
  76          */
  77         if (depth != 1)
  78                 return 0;
  79
  80         if (strcmp(uname, "chosen") == 0)
  81                 return 0;
  82
  83         if (strcmp(uname, "hypervisor") == 0 &&
  84             of_flat_dt_is_compatible(node, "xen,xen"))
  85                 return 0;
  86
  87         /*
  88          * This node at depth 1 is neither a chosen node nor a xen node,
  89          * which we do not expect.
  90          */
  91         return 1;
  92 }
  93
  94 /*
  95  * __acpi_map_table() will be called before page_init(), so early_ioremap()
  96  * or early_memremap() should be called here to for ACPI table mapping.
  97  */
  98 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
  99 {
 100         if (!size)
 101                 return NULL;
 102
 103         return early_memremap(phys, size);
 104 }
 105
 106 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
 107 {
 108         if (!map || !size)
 109                 return;
 110
 111         early_memunmap(map, size);
 112 }
 113
 114 bool __init acpi_psci_present(void)
 115 {
 116         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
 117 }
 118
 119 /* Whether HVC must be used instead of SMC as the PSCI conduit */
 120 bool acpi_psci_use_hvc(void)
 121 {
 122         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
 123 }
 124
 125 /*
 126  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
 127  *                            checks on it
 128  *
 129  * Return 0 on success,  <0 on failure
 130  */
 131 static int __init acpi_fadt_sanity_check(void)
 132 {
 133         struct acpi_table_header *table;
 134         struct acpi_table_fadt *fadt;
 135         acpi_status status;
 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(ACPI_SIG_FADT, 0, &table);
 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() creates FADT table mapping that
 174          * should be released after parsing and before resuming boot
 175          */
 176         acpi_put_table(table);
 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_acpi_spcr_enable)
 234                         early_init_dt_scan_chosen_stdout();
 235         } else {
 236                 acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
 237                 if (IS_ENABLED(CONFIG_ACPI_BGRT))
 238                         acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
 239         }
 240 }
 241
 242 #ifdef CONFIG_ACPI_APEI
 243 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
 244 {
 245         /*
 246          * According to "Table 8 Map: EFI memory types to AArch64 memory
 247          * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
 248          * mapped to a corresponding MAIR attribute encoding.
 249          * The EFI memory attribute advises all possible capabilities
 250          * of a memory region. We use the most efficient capability.
 251          */
 252
 253         u64 attr;
 254
 255         attr = efi_mem_attributes(addr);
 256         if (attr & EFI_MEMORY_WB)
 257                 return PAGE_KERNEL;
 258         if (attr & EFI_MEMORY_WT)
 259                 return __pgprot(PROT_NORMAL_WT);
 260         if (attr & EFI_MEMORY_WC)
 261                 return __pgprot(PROT_NORMAL_NC);
 262         return __pgprot(PROT_DEVICE_nGnRnE);
 263 }
 264 #endif