text: /*
   *  ARM64 Specific Low-Level ACPI Boot Support
   *
   *  Copyright (C) 2013-2014, Linaro Ltd.
   *	Author: Al Stone <al.stone@linaro.org>
   *	Author: Graeme Gregory <graeme.gregory@linaro.org>
   *	Author: Hanjun Guo <hanjun.guo@linaro.org>
   *	Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
   *	Author: Naresh Bhat <naresh.bhat@linaro.org>
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License version 2 as
   *  published by the Free Software Foundation.
   */
  
  #define pr_fmt(fmt) "ACPI: " fmt
  
  #include <linux/acpi.h>
  #include <linux/bootmem.h>
  #include <linux/cpumask.h>
  #include <linux/init.h>
  #include <linux/irq.h>
  #include <linux/irqdomain.h>
  #include <linux/memblock.h>
  #include <linux/of_fdt.h>
  #include <linux/smp.h>
  
  #include <asm/cputype.h>
  #include <asm/cpu_ops.h>
  #include <asm/smp_plat.h>
  
  #ifdef CONFIG_ACPI_APEI
  # include <linux/efi.h>
  # include <asm/pgtable.h>
  #endif
  
  int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
  int acpi_disabled = 1;
  EXPORT_SYMBOL(acpi_disabled);
  
  int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
  EXPORT_SYMBOL(acpi_pci_disabled);
  
  static bool param_acpi_off __initdata;
  static bool param_acpi_force __initdata;
  
  static int __init parse_acpi(char *arg)
  {
  	if (!arg)
  		return -EINVAL;
  
  	/* "acpi=off" disables both ACPI table parsing and interpreter */
  	if (strcmp(arg, "off") == 0)
  		param_acpi_off = true;
  	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
  		param_acpi_force = true;
  	else
  		return -EINVAL;	/* Core will print when we return error */
  
  	return 0;
  }
  early_param("acpi", parse_acpi);
  
  static int __init dt_scan_depth1_nodes(unsigned long node,
  				       const char *uname, int depth,
  				       void *data)
  {
  	/*
  	 * Return 1 as soon as we encounter a node at depth 1 that is
  	 * not the /chosen node.
  	 */
  	if (depth == 1 && (strcmp(uname, "chosen") != 0))
  		return 1;
  	return 0;
  }
  
  /*
   * __acpi_map_table() will be called before page_init(), so early_ioremap()
   * or early_memremap() should be called here to for ACPI table mapping.
   */
  char *__init __acpi_map_table(unsigned long phys, unsigned long size)
  {
  	if (!size)
  		return NULL;
  
  	return early_memremap(phys, size);
  }
  
  void __init __acpi_unmap_table(char *map, unsigned long size)
  {
  	if (!map || !size)
  		return;
  
  	early_memunmap(map, size);
  }
  
  bool __init acpi_psci_present(void)
  {
  	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
  }
  
  /* Whether HVC must be used instead of SMC as the PSCI conduit */
  bool __init acpi_psci_use_hvc(void)
  {
  	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
  }
  
  /*
   * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
   *			      checks on it
   *
   * Return 0 on success,  <0 on failure
   */
  static int __init acpi_fadt_sanity_check(void)
  {
  	struct acpi_table_header *table;
  	struct acpi_table_fadt *fadt;
  	acpi_status status;
  	acpi_size tbl_size;
  	int ret = 0;
  
  	/*
  	 * FADT is required on arm64; retrieve it to check its presence
  	 * and carry out revision and ACPI HW reduced compliancy tests
  	 */
  	status = acpi_get_table_with_size(ACPI_SIG_FADT, 0, &table, &tbl_size);
  	if (ACPI_FAILURE(status)) {
  		const char *msg = acpi_format_exception(status);
  
  		pr_err("Failed to get FADT table, %s\n", msg);
  		return -ENODEV;
  	}
  
  	fadt = (struct acpi_table_fadt *)table;
  
  	/*
  	 * Revision in table header is the FADT Major revision, and there
  	 * is a minor revision of FADT which was introduced by ACPI 5.1,
  	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
  	 * boot protocol configuration data.
  	 */
  	if (table->revision < 5 ||
  	   (table->revision == 5 && fadt->minor_revision < 1)) {
  		pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n",
  		       table->revision, fadt->minor_revision);
  		ret = -EINVAL;
  		goto out;
  	}
  
  	if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
  		pr_err("FADT not ACPI hardware reduced compliant\n");
  		ret = -EINVAL;
  	}
  
  out:
  	/*
  	 * acpi_get_table_with_size() creates FADT table mapping that
  	 * should be released after parsing and before resuming boot
  	 */
  	early_acpi_os_unmap_memory(table, tbl_size);
  	return ret;
  }
  
  /*
   * acpi_boot_table_init() called from setup_arch(), always.
   *	1. find RSDP and get its address, and then find XSDT
   *	2. extract all tables and checksums them all
   *	3. check ACPI FADT revision
   *	4. check ACPI FADT HW reduced flag
   *
   * We can parse ACPI boot-time tables such as MADT after
   * this function is called.
   *
   * On return ACPI is enabled if either:
   *
   * - ACPI tables are initialized and sanity checks passed
   * - acpi=force was passed in the command line and ACPI was not disabled
   *   explicitly through acpi=off command line parameter
   *
   * ACPI is disabled on function return otherwise
   */
  void __init acpi_boot_table_init(void)
  {
  	/*
  	 * Enable ACPI instead of device tree unless
  	 * - ACPI has been disabled explicitly (acpi=off), or
  	 * - the device tree is not empty (it has more than just a /chosen node)
  	 *   and ACPI has not been force enabled (acpi=force)
  	 */
  	if (param_acpi_off ||
  	    (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
  		return;
  
  	/*
  	 * ACPI is disabled at this point. Enable it in order to parse
  	 * the ACPI tables and carry out sanity checks
  	 */
  	enable_acpi();
  
  	/*
  	 * If ACPI tables are initialized and FADT sanity checks passed,
  	 * leave ACPI enabled and carry on booting; otherwise disable ACPI
  	 * on initialization error.
  	 * If acpi=force was passed on the command line it forces ACPI
  	 * to be enabled even if its initialization failed.
  	 */
  	if (acpi_table_init() || acpi_fadt_sanity_check()) {
  		pr_err("Failed to init ACPI tables\n");
  		if (!param_acpi_force)
  			disable_acpi();
  	}
  }
  
  #ifdef CONFIG_ACPI_APEI
  pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
  {
  	/*
  	 * According to "Table 8 Map: EFI memory types to AArch64 memory
  	 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
  	 * mapped to a corresponding MAIR attribute encoding.
  	 * The EFI memory attribute advises all possible capabilities
  	 * of a memory region. We use the most efficient capability.
  	 */
  
  	u64 attr;
  
  	attr = efi_mem_attributes(addr);
  	if (attr & EFI_MEMORY_WB)
  		return PAGE_KERNEL;
  	if (attr & EFI_MEMORY_WT)
  		return __pgprot(PROT_NORMAL_WT);
  	if (attr & EFI_MEMORY_WC)
  		return __pgprot(PROT_NORMAL_NC);
  	return __pgprot(PROT_DEVICE_nGnRnE);
  }
  #endif
  