// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Copyright (C) 2005 Intel Corporation
   * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
   *
   *	Alex Chiang <achiang@hp.com>
   *	- Unified x86/ia64 implementations

   *
   * I/O APIC hotplug support
   *	Yinghai Lu <yinghai@kernel.org>
   *	Jiang Liu <jiang.liu@intel.com>

   */

  #include <linux/export.h>

  #include <linux/acpi.h>

  #include <acpi/processor.h>

  static struct acpi_table_madt *get_madt_table(void)
  {
  	static struct acpi_table_madt *madt;
  	static int read_madt;
  
  	if (!read_madt) {
  		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
  					(struct acpi_table_header **)&madt)))
  			madt = NULL;
  		read_madt++;
  	}
  
  	return madt;
  }

  static int map_lapic_id(struct acpi_subtable_header *entry,

  		 u32 acpi_id, phys_cpuid_t *apic_id)

  {
  	struct acpi_madt_local_apic *lapic =

  		container_of(entry, struct acpi_madt_local_apic, header);

  	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))

  		return -ENODEV;

  
  	if (lapic->processor_id != acpi_id)

  		return -EINVAL;

  
  	*apic_id = lapic->id;

  	return 0;

  }
  
  static int map_x2apic_id(struct acpi_subtable_header *entry,

  		int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)

  {
  	struct acpi_madt_local_x2apic *apic =

  		container_of(entry, struct acpi_madt_local_x2apic, header);

  	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))

  		return -ENODEV;

  	if (device_declaration && (apic->uid == acpi_id)) {
  		*apic_id = apic->local_apic_id;

  		return 0;

  	}

  	return -EINVAL;

  }
  
  static int map_lsapic_id(struct acpi_subtable_header *entry,

  		int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)

  {
  	struct acpi_madt_local_sapic *lsapic =

  		container_of(entry, struct acpi_madt_local_sapic, header);

  	if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))

  		return -ENODEV;

  	if (device_declaration) {

  		if ((entry->length < 16) || (lsapic->uid != acpi_id))

  			return -EINVAL;

  	} else if (lsapic->processor_id != acpi_id)

  		return -EINVAL;

  	*apic_id = (lsapic->id << 8) | lsapic->eid;

  	return 0;

  }

  /*
   * Retrieve the ARM CPU physical identifier (MPIDR)
   */
  static int map_gicc_mpidr(struct acpi_subtable_header *entry,

  		int device_declaration, u32 acpi_id, phys_cpuid_t *mpidr)

  {
  	struct acpi_madt_generic_interrupt *gicc =
  	    container_of(entry, struct acpi_madt_generic_interrupt, header);

  	if (!(gicc->flags & ACPI_MADT_ENABLED))

  		return -ENODEV;
  
  	/* device_declaration means Device object in DSDT, in the
  	 * GIC interrupt model, logical processors are required to
  	 * have a Processor Device object in the DSDT, so we should
  	 * check device_declaration here
  	 */
  	if (device_declaration && (gicc->uid == acpi_id)) {
  		*mpidr = gicc->arm_mpidr;
  		return 0;
  	}
  
  	return -EINVAL;
  }

  static phys_cpuid_t map_madt_entry(struct acpi_table_madt *madt,

  				   int type, u32 acpi_id)

  {
  	unsigned long madt_end, entry;

  	phys_cpuid_t phys_id = PHYS_CPUID_INVALID;	/* CPU hardware ID */

  
  	if (!madt)

  		return phys_id;

  
  	entry = (unsigned long)madt;
  	madt_end = entry + madt->header.length;
  
  	/* Parse all entries looking for a match. */
  
  	entry += sizeof(struct acpi_table_madt);
  	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
  		struct acpi_subtable_header *header =
  			(struct acpi_subtable_header *)entry;
  		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {

  			if (!map_lapic_id(header, acpi_id, &phys_id))

  				break;
  		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {

  			if (!map_x2apic_id(header, type, acpi_id, &phys_id))

  				break;
  		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {

  			if (!map_lsapic_id(header, type, acpi_id, &phys_id))

  				break;

  		} else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) {

  			if (!map_gicc_mpidr(header, type, acpi_id, &phys_id))

  				break;

  		}
  		entry += header->length;
  	}

  	return phys_id;

  }

  phys_cpuid_t __init acpi_map_madt_entry(u32 acpi_id)
  {
  	struct acpi_table_madt *madt = NULL;

  	phys_cpuid_t rv;

  	acpi_get_table(ACPI_SIG_MADT, 0,
  		       (struct acpi_table_header **)&madt);

  	if (!madt)
  		return PHYS_CPUID_INVALID;

  	rv = map_madt_entry(madt, 1, acpi_id);

  	acpi_put_table((struct acpi_table_header *)madt);

  
  	return rv;
  }

  static phys_cpuid_t map_mat_entry(acpi_handle handle, int type, u32 acpi_id)

  {
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	union acpi_object *obj;
  	struct acpi_subtable_header *header;

  	phys_cpuid_t phys_id = PHYS_CPUID_INVALID;

  
  	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
  		goto exit;
  
  	if (!buffer.length || !buffer.pointer)
  		goto exit;
  
  	obj = buffer.pointer;
  	if (obj->type != ACPI_TYPE_BUFFER ||
  	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
  		goto exit;
  	}
  
  	header = (struct acpi_subtable_header *)obj->buffer.pointer;

  	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC)

  		map_lapic_id(header, acpi_id, &phys_id);

  	else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC)

  		map_lsapic_id(header, type, acpi_id, &phys_id);

  	else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC)

  		map_x2apic_id(header, type, acpi_id, &phys_id);

  	else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT)

  		map_gicc_mpidr(header, type, acpi_id, &phys_id);

  
  exit:

  	kfree(buffer.pointer);

  	return phys_id;

  }

  phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)

  {

  	phys_cpuid_t phys_id;

  	phys_id = map_mat_entry(handle, type, acpi_id);

  	if (invalid_phys_cpuid(phys_id))

  		phys_id = map_madt_entry(get_madt_table(), type, acpi_id);

  	return phys_id;

  }

  EXPORT_SYMBOL_GPL(acpi_get_phys_id);

  int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id)

  {
  #ifdef CONFIG_SMP
  	int i;
  #endif

  	if (invalid_phys_cpuid(phys_id)) {

  		/*
  		 * On UP processor, there is no _MAT or MADT table.

  		 * So above phys_id is always set to PHYS_CPUID_INVALID.

  		 *
  		 * BIOS may define multiple CPU handles even for UP processor.
  		 * For example,
  		 *
  		 * Scope (_PR)

  		 * {

  		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
  		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
  		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
  		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
  		 * }
  		 *

  		 * Ignores phys_id and always returns 0 for the processor

  		 * handle with acpi id 0 if nr_cpu_ids is 1.
  		 * This should be the case if SMP tables are not found.

  		 * Return -EINVAL for other CPU's handle.

  		 */

  		if (nr_cpu_ids <= 1 && acpi_id == 0)

  			return acpi_id;
  		else

  			return -EINVAL;

  	}

  #ifdef CONFIG_SMP

  	for_each_possible_cpu(i) {

  		if (cpu_physical_id(i) == phys_id)

  			return i;
  	}

  #else
  	/* In UP kernel, only processor 0 is valid */

  	if (phys_id == 0)
  		return phys_id;

  #endif

  	return -ENODEV;

  }

  
  int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
  {

  	phys_cpuid_t phys_id;

  	phys_id = acpi_get_phys_id(handle, type, acpi_id);

  	return acpi_map_cpuid(phys_id, acpi_id);

  }

  EXPORT_SYMBOL_GPL(acpi_get_cpuid);

  
  #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
  static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
  			 u64 *phys_addr, int *ioapic_id)
  {
  	struct acpi_madt_io_apic *ioapic = (struct acpi_madt_io_apic *)entry;
  
  	if (ioapic->global_irq_base != gsi_base)
  		return 0;
  
  	*phys_addr = ioapic->address;
  	*ioapic_id = ioapic->id;
  	return 1;
  }
  
  static int parse_madt_ioapic_entry(u32 gsi_base, u64 *phys_addr)
  {
  	struct acpi_subtable_header *hdr;
  	unsigned long madt_end, entry;
  	struct acpi_table_madt *madt;
  	int apic_id = -1;
  
  	madt = get_madt_table();
  	if (!madt)
  		return apic_id;
  
  	entry = (unsigned long)madt;
  	madt_end = entry + madt->header.length;
  
  	/* Parse all entries looking for a match. */
  	entry += sizeof(struct acpi_table_madt);
  	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
  		hdr = (struct acpi_subtable_header *)entry;
  		if (hdr->type == ACPI_MADT_TYPE_IO_APIC &&
  		    get_ioapic_id(hdr, gsi_base, phys_addr, &apic_id))
  			break;
  		else
  			entry += hdr->length;
  	}
  
  	return apic_id;
  }
  
  static int parse_mat_ioapic_entry(acpi_handle handle, u32 gsi_base,
  				  u64 *phys_addr)
  {
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	struct acpi_subtable_header *header;
  	union acpi_object *obj;
  	int apic_id = -1;
  
  	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
  		goto exit;
  
  	if (!buffer.length || !buffer.pointer)
  		goto exit;
  
  	obj = buffer.pointer;
  	if (obj->type != ACPI_TYPE_BUFFER ||
  	    obj->buffer.length < sizeof(struct acpi_subtable_header))
  		goto exit;
  
  	header = (struct acpi_subtable_header *)obj->buffer.pointer;
  	if (header->type == ACPI_MADT_TYPE_IO_APIC)
  		get_ioapic_id(header, gsi_base, phys_addr, &apic_id);
  
  exit:
  	kfree(buffer.pointer);
  	return apic_id;
  }
  
  /**
   * acpi_get_ioapic_id - Get IOAPIC ID and physical address matching @gsi_base
   * @handle:	ACPI object for IOAPIC device
   * @gsi_base:	GSI base to match with
   * @phys_addr:	Pointer to store physical address of matching IOAPIC record
   *
   * Walk resources returned by ACPI_MAT method, then ACPI MADT table, to search
   * for an ACPI IOAPIC record matching @gsi_base.
   * Return IOAPIC id and store physical address in @phys_addr if found a match,
   * otherwise return <0.
   */
  int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr)
  {
  	int apic_id;
  
  	apic_id = parse_mat_ioapic_entry(handle, gsi_base, phys_addr);
  	if (apic_id == -1)
  		apic_id = parse_madt_ioapic_entry(gsi_base, phys_addr);
  
  	return apic_id;
  }
  #endif /* CONFIG_ACPI_HOTPLUG_IOAPIC */