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 #include <linux/serial_core.h>
  28
  29 #include <asm/cputype.h>
  30 #include <asm/cpu_ops.h>
  31 #include <asm/smp_plat.h>
  32
  33 #ifdef CONFIG_ACPI_APEI
  34 # include <linux/efi.h>
  35 # include <asm/pgtable.h>
  36 #endif
  37
  38 int acpi_noirq = 1;             /* skip ACPI IRQ initialization */
  39 int acpi_disabled = 1;
  40 EXPORT_SYMBOL(acpi_disabled);
  41
  42 int acpi_pci_disabled = 1;      /* skip ACPI PCI scan and IRQ initialization */
  43 EXPORT_SYMBOL(acpi_pci_disabled);
  44
  45 static bool param_acpi_off __initdata;
  46 static bool param_acpi_on __initdata;
  47 static bool param_acpi_force __initdata;
  48
  49 static int __init parse_acpi(char *arg)
  50 {
  51         if (!arg)
  52                 return -EINVAL;
  53
  54         /* "acpi=off" disables both ACPI table parsing and interpreter */
  55         if (strcmp(arg, "off") == 0)
  56                 param_acpi_off = true;
  57         else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
  58                 param_acpi_on = true;
  59         else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
  60                 param_acpi_force = true;
  61         else
  62                 return -EINVAL; /* Core will print when we return error */
  63
  64         return 0;
  65 }
  66 early_param("acpi", parse_acpi);
  67
  68 static int __init dt_scan_depth1_nodes(unsigned long node,
  69                                        const char *uname, int depth,
  70                                        void *data)
  71 {
  72         /*
  73          * Ignore anything not directly under the root node; we'll
  74          * catch its parent instead.
  75          */
  76         if (depth != 1)
  77                 return 0;
  78
  79         if (strcmp(uname, "chosen") == 0)
  80                 return 0;
  81
  82         if (strcmp(uname, "hypervisor") == 0 &&
  83             of_flat_dt_is_compatible(node, "xen,xen"))
  84                 return 0;
  85
  86         /*
  87          * This node at depth 1 is neither a chosen node nor a xen node,
  88          * which we do not expect.
  89          */
  90         return 1;
  91 }
  92
  93 /*
  94  * __acpi_map_table() will be called before page_init(), so early_ioremap()
  95  * or early_memremap() should be called here to for ACPI table mapping.
  96  */
  97 char *__init __acpi_map_table(unsigned long phys, unsigned long size)
  98 {
  99         if (!size)
 100                 return NULL;
 101
 102         return early_memremap(phys, size);
 103 }
 104
 105 void __init __acpi_unmap_table(char *map, unsigned long size)
 106 {
 107         if (!map || !size)
 108                 return;
 109
 110         early_memunmap(map, size);
 111 }
 112
 113 bool __init acpi_psci_present(void)
 114 {
 115         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
 116 }
 117
 118 /* Whether HVC must be used instead of SMC as the PSCI conduit */
 119 bool __init acpi_psci_use_hvc(void)
 120 {
 121         return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
 122 }
 123
 124 /*
 125  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
 126  *                            checks on it
 127  *
 128  * Return 0 on success,  <0 on failure
 129  */
 130 static int __init acpi_fadt_sanity_check(void)
 131 {
 132         struct acpi_table_header *table;
 133         struct acpi_table_fadt *fadt;
 134         acpi_status status;
 135         int ret = 0;
 136
 137         /*
 138          * FADT is required on arm64; retrieve it to check its presence
 139          * and carry out revision and ACPI HW reduced compliancy tests
 140          */
 141         status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
 142         if (ACPI_FAILURE(status)) {
 143                 const char *msg = acpi_format_exception(status);
 144
 145                 pr_err("Failed to get FADT table, %s\n", msg);
 146                 return -ENODEV;
 147         }
 148
 149         fadt = (struct acpi_table_fadt *)table;
 150
 151         /*
 152          * Revision in table header is the FADT Major revision, and there
 153          * is a minor revision of FADT which was introduced by ACPI 5.1,
 154          * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
 155          * boot protocol configuration data.
 156          */
 157         if (table->revision < 5 ||
 158            (table->revision == 5 && fadt->minor_revision < 1)) {
 159                 pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n",
 160                        table->revision, fadt->minor_revision);
 161                 ret = -EINVAL;
 162                 goto out;
 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_init_is_deferred)
 233                         early_init_dt_scan_chosen_stdout();
 234         } else {
 235                 parse_spcr(earlycon_init_is_deferred);
 236         }
 237 }
 238
 239 #ifdef CONFIG_ACPI_APEI
 240 pgprot_t arch_apei_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 #endif