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/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
  28 #include <asm/cputype.h>
  29 #include <asm/cpu_ops.h>
  30 #include <asm/smp_plat.h>
  31
  32 int acpi_noirq = 1;             /* skip ACPI IRQ initialization */
  33 int acpi_disabled = 1;
  34 EXPORT_SYMBOL(acpi_disabled);
  35
  36 int acpi_pci_disabled = 1;      /* skip ACPI PCI scan and IRQ initialization */
  37 EXPORT_SYMBOL(acpi_pci_disabled);
  38
  39 static bool param_acpi_off __initdata;
  40 static bool param_acpi_force __initdata;
  41
  42 static int __init parse_acpi(char *arg)
  43 {
  44         if (!arg)
  45                 return -EINVAL;
  46
  47         /* "acpi=off" disables both ACPI table parsing and interpreter */
  48         if (strcmp(arg, "off") == 0)
  49                 param_acpi_off = true;
  50         else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
  51                 param_acpi_force = true;
  52         else
  53                 return -EINVAL; /* Core will print when we return error */
  54
  55         return 0;
  56 }
  57 early_param("acpi", parse_acpi);
  58
  59 static int __init dt_scan_depth1_nodes(unsigned long node,
  60                                        const char *uname, int depth,
  61                                        void *data)
  62 {
  63         /*
  64          * Return 1 as soon as we encounter a node at depth 1 that is
  65          * not the /chosen node.
  66          */
  67         if (depth == 1 && (strcmp(uname, "chosen") != 0))
  68                 return 1;
  69         return 0;
  70 }
  71
  72 /*
  73  * __acpi_map_table() will be called before page_init(), so early_ioremap()
  74  * or early_memremap() should be called here to for ACPI table mapping.
  75  */
  76 char *__init __acpi_map_table(unsigned long phys, unsigned long size)
  77 {
  78         if (!size)
  79                 return NULL;
  80
  81         return early_memremap(phys, size);
  82 }
  83
  84 void __init __acpi_unmap_table(char *map, unsigned long size)
  85 {
  86         if (!map || !size)
  87                 return;
  88
  89         early_memunmap(map, size);
  90 }
  91
  92 bool __init acpi_psci_present(void)
  93 {
  94         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
  95 }
  96
  97 /* Whether HVC must be used instead of SMC as the PSCI conduit */
  98 bool __init acpi_psci_use_hvc(void)
  99 {
 100         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
 101 }
 102
 103 /*
 104  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
 105  *                            checks on it
 106  *
 107  * Return 0 on success,  <0 on failure
 108  */
 109 static int __init acpi_fadt_sanity_check(void)
 110 {
 111         struct acpi_table_header *table;
 112         struct acpi_table_fadt *fadt;
 113         acpi_status status;
 114         acpi_size tbl_size;
 115         int ret = 0;
 116
 117         /*
 118          * FADT is required on arm64; retrieve it to check its presence
 119          * and carry out revision and ACPI HW reduced compliancy tests
 120          */
 121         status = acpi_get_table_with_size(ACPI_SIG_FADT, 0, &table, &tbl_size);
 122         if (ACPI_FAILURE(status)) {
 123                 const char *msg = acpi_format_exception(status);
 124
 125                 pr_err("Failed to get FADT table, %s\n", msg);
 126                 return -ENODEV;
 127         }
 128
 129         fadt = (struct acpi_table_fadt *)table;
 130
 131         /*
 132          * Revision in table header is the FADT Major revision, and there
 133          * is a minor revision of FADT which was introduced by ACPI 5.1,
 134          * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
 135          * boot protocol configuration data.
 136          */
 137         if (table->revision < 5 ||
 138            (table->revision == 5 && fadt->minor_revision < 1)) {
 139                 pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n",
 140                        table->revision, fadt->minor_revision);
 141                 ret = -EINVAL;
 142                 goto out;
 143         }
 144
 145         if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
 146                 pr_err("FADT not ACPI hardware reduced compliant\n");
 147                 ret = -EINVAL;
 148         }
 149
 150 out:
 151         /*
 152          * acpi_get_table_with_size() creates FADT table mapping that
 153          * should be released after parsing and before resuming boot
 154          */
 155         early_acpi_os_unmap_memory(table, tbl_size);
 156         return ret;
 157 }
 158
 159 /*
 160  * acpi_boot_table_init() called from setup_arch(), always.
 161  *      1. find RSDP and get its address, and then find XSDT
 162  *      2. extract all tables and checksums them all
 163  *      3. check ACPI FADT revision
 164  *      4. check ACPI FADT HW reduced flag
 165  *
 166  * We can parse ACPI boot-time tables such as MADT after
 167  * this function is called.
 168  *
 169  * On return ACPI is enabled if either:
 170  *
 171  * - ACPI tables are initialized and sanity checks passed
 172  * - acpi=force was passed in the command line and ACPI was not disabled
 173  *   explicitly through acpi=off command line parameter
 174  *
 175  * ACPI is disabled on function return otherwise
 176  */
 177 void __init acpi_boot_table_init(void)
 178 {
 179         /*
 180          * Enable ACPI instead of device tree unless
 181          * - ACPI has been disabled explicitly (acpi=off), or
 182          * - the device tree is not empty (it has more than just a /chosen node)
 183          *   and ACPI has not been force enabled (acpi=force)
 184          */
 185         if (param_acpi_off ||
 186             (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
 187                 return;
 188
 189         /*
 190          * ACPI is disabled at this point. Enable it in order to parse
 191          * the ACPI tables and carry out sanity checks
 192          */
 193         enable_acpi();
 194
 195         /*
 196          * If ACPI tables are initialized and FADT sanity checks passed,
 197          * leave ACPI enabled and carry on booting; otherwise disable ACPI
 198          * on initialization error.
 199          * If acpi=force was passed on the command line it forces ACPI
 200          * to be enabled even if its initialization failed.
 201          */
 202         if (acpi_table_init() || acpi_fadt_sanity_check()) {
 203                 pr_err("Failed to init ACPI tables\n");
 204                 if (!param_acpi_force)
 205                         disable_acpi();
 206         }
 207 }
 208
 209 void __init acpi_gic_init(void)
 210 {
 211         struct acpi_table_header *table;
 212         acpi_status status;
 213         acpi_size tbl_size;
 214         int err;
 215
 216         if (acpi_disabled)
 217                 return;
 218
 219         status = acpi_get_table_with_size(ACPI_SIG_MADT, 0, &table, &tbl_size);
 220         if (ACPI_FAILURE(status)) {
 221                 const char *msg = acpi_format_exception(status);
 222
 223                 pr_err("Failed to get MADT table, %s\n", msg);
 224                 return;
 225         }
 226
 227         err = gic_v2_acpi_init(table);
 228         if (err)
 229                 pr_err("Failed to initialize GIC IRQ controller");
 230
 231         early_acpi_os_unmap_memory((char *)table, tbl_size);
 232 }