/*

   * Copyright (C) 2007-2010 Advanced Micro Devices, Inc.

   * Author: Joerg Roedel <jroedel@suse.de>

   *         Leo Duran <leo.duran@amd.com>
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   */
  
  #include <linux/pci.h>
  #include <linux/acpi.h>

  #include <linux/list.h>

  #include <linux/bitmap.h>

  #include <linux/slab.h>

  #include <linux/syscore_ops.h>

  #include <linux/interrupt.h>
  #include <linux/msi.h>

  #include <linux/amd-iommu.h>

  #include <linux/export.h>

  #include <linux/iommu.h>

  #include <asm/pci-direct.h>

  #include <asm/iommu.h>

  #include <asm/gart.h>

  #include <asm/x86_init.h>

  #include <asm/iommu_table.h>

  #include <asm/io_apic.h>

  #include <asm/irq_remapping.h>

  
  #include "amd_iommu_proto.h"
  #include "amd_iommu_types.h"

  #include "irq_remapping.h"

  /*
   * definitions for the ACPI scanning code
   */

  #define IVRS_HEADER_LENGTH 48

  #define ACPI_IVHD_TYPE_MAX_SUPPORTED	0x40

  #define ACPI_IVMD_TYPE_ALL              0x20
  #define ACPI_IVMD_TYPE                  0x21
  #define ACPI_IVMD_TYPE_RANGE            0x22
  
  #define IVHD_DEV_ALL                    0x01
  #define IVHD_DEV_SELECT                 0x02
  #define IVHD_DEV_SELECT_RANGE_START     0x03
  #define IVHD_DEV_RANGE_END              0x04
  #define IVHD_DEV_ALIAS                  0x42
  #define IVHD_DEV_ALIAS_RANGE            0x43
  #define IVHD_DEV_EXT_SELECT             0x46
  #define IVHD_DEV_EXT_SELECT_RANGE       0x47

  #define IVHD_DEV_SPECIAL		0x48

  #define IVHD_DEV_ACPI_HID		0xf0

  #define UID_NOT_PRESENT                 0
  #define UID_IS_INTEGER                  1
  #define UID_IS_CHARACTER                2

  #define IVHD_SPECIAL_IOAPIC		1
  #define IVHD_SPECIAL_HPET		2

  #define IVHD_FLAG_HT_TUN_EN_MASK        0x01
  #define IVHD_FLAG_PASSPW_EN_MASK        0x02
  #define IVHD_FLAG_RESPASSPW_EN_MASK     0x04
  #define IVHD_FLAG_ISOC_EN_MASK          0x08

  
  #define IVMD_FLAG_EXCL_RANGE            0x08
  #define IVMD_FLAG_UNITY_MAP             0x01
  
  #define ACPI_DEVFLAG_INITPASS           0x01
  #define ACPI_DEVFLAG_EXTINT             0x02
  #define ACPI_DEVFLAG_NMI                0x04
  #define ACPI_DEVFLAG_SYSMGT1            0x10
  #define ACPI_DEVFLAG_SYSMGT2            0x20
  #define ACPI_DEVFLAG_LINT0              0x40
  #define ACPI_DEVFLAG_LINT1              0x80
  #define ACPI_DEVFLAG_ATSDIS             0x10000000

  #define LOOP_TIMEOUT	100000

  /*
   * ACPI table definitions
   *
   * These data structures are laid over the table to parse the important values
   * out of it.
   */
  
  /*
   * structure describing one IOMMU in the ACPI table. Typically followed by one
   * or more ivhd_entrys.
   */

  struct ivhd_header {
  	u8 type;
  	u8 flags;
  	u16 length;
  	u16 devid;
  	u16 cap_ptr;
  	u64 mmio_phys;
  	u16 pci_seg;
  	u16 info;

  	u32 efr_attr;
  
  	/* Following only valid on IVHD type 11h and 40h */
  	u64 efr_reg; /* Exact copy of MMIO_EXT_FEATURES */
  	u64 res;

  } __attribute__((packed));

  /*
   * A device entry describing which devices a specific IOMMU translates and
   * which requestor ids they use.
   */

  struct ivhd_entry {
  	u8 type;
  	u16 devid;
  	u8 flags;
  	u32 ext;

  	u32 hidh;
  	u64 cid;
  	u8 uidf;
  	u8 uidl;
  	u8 uid;

  } __attribute__((packed));

  /*
   * An AMD IOMMU memory definition structure. It defines things like exclusion
   * ranges for devices and regions that should be unity mapped.
   */

  struct ivmd_header {
  	u8 type;
  	u8 flags;
  	u16 length;
  	u16 devid;
  	u16 aux;
  	u64 resv;
  	u64 range_start;
  	u64 range_length;
  } __attribute__((packed));

  bool amd_iommu_dump;

  bool amd_iommu_irq_remap __read_mostly;

  int amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_VAPIC;

  static bool amd_iommu_detected;

  static bool __initdata amd_iommu_disabled;

  static int amd_iommu_target_ivhd_type;

  u16 amd_iommu_last_bdf;			/* largest PCI device id we have
  					   to handle */

  LIST_HEAD(amd_iommu_unity_map);		/* a list of required unity mappings

  					   we find in ACPI */

  bool amd_iommu_unmap_flush;		/* if true, flush on every unmap */

  LIST_HEAD(amd_iommu_list);		/* list of all AMD IOMMUs in the

  					   system */

  /* Array to assign indices to IOMMUs*/
  struct amd_iommu *amd_iommus[MAX_IOMMUS];
  int amd_iommus_present;

  /* IOMMUs have a non-present cache? */
  bool amd_iommu_np_cache __read_mostly;

  bool amd_iommu_iotlb_sup __read_mostly = true;

  u32 amd_iommu_max_pasid __read_mostly = ~0;

  bool amd_iommu_v2_present __read_mostly;

  static bool amd_iommu_pc_present __read_mostly;

  bool amd_iommu_force_isolation __read_mostly;

  /*

   * List of protection domains - used during resume
   */
  LIST_HEAD(amd_iommu_pd_list);
  spinlock_t amd_iommu_pd_lock;
  
  /*

   * Pointer to the device table which is shared by all AMD IOMMUs
   * it is indexed by the PCI device id or the HT unit id and contains
   * information about the domain the device belongs to as well as the
   * page table root pointer.
   */

  struct dev_table_entry *amd_iommu_dev_table;

  
  /*
   * The alias table is a driver specific data structure which contains the
   * mappings of the PCI device ids to the actual requestor ids on the IOMMU.
   * More than one device can share the same requestor id.
   */

  u16 *amd_iommu_alias_table;

  
  /*
   * The rlookup table is used to find the IOMMU which is responsible
   * for a specific device. It is also indexed by the PCI device id.
   */

  struct amd_iommu **amd_iommu_rlookup_table;

  
  /*

   * This table is used to find the irq remapping table for a given device id
   * quickly.
   */
  struct irq_remap_table **irq_lookup_table;
  
  /*

   * AMD IOMMU allows up to 2^16 different protection domains. This is a bitmap

   * to know which ones are already in use.
   */

  unsigned long *amd_iommu_pd_alloc_bitmap;

  static u32 dev_table_size;	/* size of the device table */
  static u32 alias_table_size;	/* size of the alias table */
  static u32 rlookup_table_size;	/* size if the rlookup table */

  enum iommu_init_state {
  	IOMMU_START_STATE,
  	IOMMU_IVRS_DETECTED,
  	IOMMU_ACPI_FINISHED,
  	IOMMU_ENABLED,
  	IOMMU_PCI_INIT,
  	IOMMU_INTERRUPTS_EN,
  	IOMMU_DMA_OPS,
  	IOMMU_INITIALIZED,
  	IOMMU_NOT_FOUND,
  	IOMMU_INIT_ERROR,
  };

  /* Early ioapic and hpet maps from kernel command line */
  #define EARLY_MAP_SIZE		4
  static struct devid_map __initdata early_ioapic_map[EARLY_MAP_SIZE];
  static struct devid_map __initdata early_hpet_map[EARLY_MAP_SIZE];

  static struct acpihid_map_entry __initdata early_acpihid_map[EARLY_MAP_SIZE];

  static int __initdata early_ioapic_map_size;
  static int __initdata early_hpet_map_size;

  static int __initdata early_acpihid_map_size;

  static bool __initdata cmdline_maps;

  static enum iommu_init_state init_state = IOMMU_START_STATE;

  static int amd_iommu_enable_interrupts(void);

  static int __init iommu_go_to_state(enum iommu_init_state state);

  static void init_device_table_dma(void);

  static int iommu_pc_get_set_reg_val(struct amd_iommu *iommu,
  				    u8 bank, u8 cntr, u8 fxn,
  				    u64 *value, bool is_write);

  static inline void update_last_devid(u16 devid)
  {
  	if (devid > amd_iommu_last_bdf)
  		amd_iommu_last_bdf = devid;
  }

  static inline unsigned long tbl_size(int entry_size)
  {
  	unsigned shift = PAGE_SHIFT +

  			 get_order(((int)amd_iommu_last_bdf + 1) * entry_size);

  
  	return 1UL << shift;
  }

  /* Access to l1 and l2 indexed register spaces */
  
  static u32 iommu_read_l1(struct amd_iommu *iommu, u16 l1, u8 address)
  {
  	u32 val;
  
  	pci_write_config_dword(iommu->dev, 0xf8, (address | l1 << 16));
  	pci_read_config_dword(iommu->dev, 0xfc, &val);
  	return val;
  }
  
  static void iommu_write_l1(struct amd_iommu *iommu, u16 l1, u8 address, u32 val)
  {
  	pci_write_config_dword(iommu->dev, 0xf8, (address | l1 << 16 | 1 << 31));
  	pci_write_config_dword(iommu->dev, 0xfc, val);
  	pci_write_config_dword(iommu->dev, 0xf8, (address | l1 << 16));
  }
  
  static u32 iommu_read_l2(struct amd_iommu *iommu, u8 address)
  {
  	u32 val;
  
  	pci_write_config_dword(iommu->dev, 0xf0, address);
  	pci_read_config_dword(iommu->dev, 0xf4, &val);
  	return val;
  }
  
  static void iommu_write_l2(struct amd_iommu *iommu, u8 address, u32 val)
  {
  	pci_write_config_dword(iommu->dev, 0xf0, (address | 1 << 8));
  	pci_write_config_dword(iommu->dev, 0xf4, val);
  }

  /****************************************************************************
   *
   * AMD IOMMU MMIO register space handling functions
   *
   * These functions are used to program the IOMMU device registers in
   * MMIO space required for that driver.
   *
   ****************************************************************************/

  /*
   * This function set the exclusion range in the IOMMU. DMA accesses to the
   * exclusion range are passed through untranslated
   */

  static void iommu_set_exclusion_range(struct amd_iommu *iommu)

  {
  	u64 start = iommu->exclusion_start & PAGE_MASK;
  	u64 limit = (start + iommu->exclusion_length) & PAGE_MASK;
  	u64 entry;
  
  	if (!iommu->exclusion_start)
  		return;
  
  	entry = start | MMIO_EXCL_ENABLE_MASK;
  	memcpy_toio(iommu->mmio_base + MMIO_EXCL_BASE_OFFSET,
  			&entry, sizeof(entry));
  
  	entry = limit;
  	memcpy_toio(iommu->mmio_base + MMIO_EXCL_LIMIT_OFFSET,
  			&entry, sizeof(entry));
  }

  /* Programs the physical address of the device table into the IOMMU hardware */

  static void iommu_set_device_table(struct amd_iommu *iommu)

  {

  	u64 entry;

  
  	BUG_ON(iommu->mmio_base == NULL);
  
  	entry = virt_to_phys(amd_iommu_dev_table);
  	entry |= (dev_table_size >> 12) - 1;
  	memcpy_toio(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET,
  			&entry, sizeof(entry));
  }

  /* Generic functions to enable/disable certain features of the IOMMU. */

  static void iommu_feature_enable(struct amd_iommu *iommu, u8 bit)

  {
  	u32 ctrl;
  
  	ctrl = readl(iommu->mmio_base + MMIO_CONTROL_OFFSET);
  	ctrl |= (1 << bit);
  	writel(ctrl, iommu->mmio_base + MMIO_CONTROL_OFFSET);
  }

  static void iommu_feature_disable(struct amd_iommu *iommu, u8 bit)

  {
  	u32 ctrl;

  	ctrl = readl(iommu->mmio_base + MMIO_CONTROL_OFFSET);

  	ctrl &= ~(1 << bit);
  	writel(ctrl, iommu->mmio_base + MMIO_CONTROL_OFFSET);
  }

  static void iommu_set_inv_tlb_timeout(struct amd_iommu *iommu, int timeout)
  {
  	u32 ctrl;
  
  	ctrl = readl(iommu->mmio_base + MMIO_CONTROL_OFFSET);
  	ctrl &= ~CTRL_INV_TO_MASK;
  	ctrl |= (timeout << CONTROL_INV_TIMEOUT) & CTRL_INV_TO_MASK;
  	writel(ctrl, iommu->mmio_base + MMIO_CONTROL_OFFSET);
  }

  /* Function to enable the hardware */

  static void iommu_enable(struct amd_iommu *iommu)

  {

  	iommu_feature_enable(iommu, CONTROL_IOMMU_EN);

  }

  static void iommu_disable(struct amd_iommu *iommu)

  {

  	/* Disable command buffer */
  	iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
  
  	/* Disable event logging and event interrupts */
  	iommu_feature_disable(iommu, CONTROL_EVT_INT_EN);
  	iommu_feature_disable(iommu, CONTROL_EVT_LOG_EN);

  	/* Disable IOMMU GA_LOG */
  	iommu_feature_disable(iommu, CONTROL_GALOG_EN);
  	iommu_feature_disable(iommu, CONTROL_GAINT_EN);

  	/* Disable IOMMU hardware itself */

  	iommu_feature_disable(iommu, CONTROL_IOMMU_EN);

  }

  /*
   * mapping and unmapping functions for the IOMMU MMIO space. Each AMD IOMMU in
   * the system has one.
   */

  static u8 __iomem * __init iommu_map_mmio_space(u64 address, u64 end)

  {

  	if (!request_mem_region(address, end, "amd_iommu")) {
  		pr_err("AMD-Vi: Can not reserve memory region %llx-%llx for mmio
  ",
  			address, end);

  		pr_err("AMD-Vi: This is a BIOS bug. Please contact your hardware vendor
  ");

  		return NULL;

  	}

  	return (u8 __iomem *)ioremap_nocache(address, end);

  }
  
  static void __init iommu_unmap_mmio_space(struct amd_iommu *iommu)
  {
  	if (iommu->mmio_base)
  		iounmap(iommu->mmio_base);

  	release_mem_region(iommu->mmio_phys, iommu->mmio_phys_end);

  }

  static inline u32 get_ivhd_header_size(struct ivhd_header *h)
  {
  	u32 size = 0;
  
  	switch (h->type) {
  	case 0x10:
  		size = 24;
  		break;
  	case 0x11:
  	case 0x40:
  		size = 40;
  		break;
  	}
  	return size;
  }

  /****************************************************************************
   *
   * The functions below belong to the first pass of AMD IOMMU ACPI table
   * parsing. In this pass we try to find out the highest device id this
   * code has to handle. Upon this information the size of the shared data
   * structures is determined later.
   *
   ****************************************************************************/
  
  /*

   * This function calculates the length of a given IVHD entry
   */
  static inline int ivhd_entry_length(u8 *ivhd)
  {

  	u32 type = ((struct ivhd_entry *)ivhd)->type;
  
  	if (type < 0x80) {
  		return 0x04 << (*ivhd >> 6);
  	} else if (type == IVHD_DEV_ACPI_HID) {
  		/* For ACPI_HID, offset 21 is uid len */
  		return *((u8 *)ivhd + 21) + 22;
  	}
  	return 0;

  }
  
  /*

   * After reading the highest device id from the IOMMU PCI capability header
   * this function looks if there is a higher device id defined in the ACPI table
   */

  static int __init find_last_devid_from_ivhd(struct ivhd_header *h)
  {
  	u8 *p = (void *)h, *end = (void *)h;
  	struct ivhd_entry *dev;

  	u32 ivhd_size = get_ivhd_header_size(h);
  
  	if (!ivhd_size) {
  		pr_err("AMD-Vi: Unsupported IVHD type %#x
  ", h->type);
  		return -EINVAL;
  	}
  
  	p += ivhd_size;

  	end += h->length;

  	while (p < end) {
  		dev = (struct ivhd_entry *)p;
  		switch (dev->type) {

  		case IVHD_DEV_ALL:
  			/* Use maximum BDF value for DEV_ALL */
  			update_last_devid(0xffff);
  			break;

  		case IVHD_DEV_SELECT:
  		case IVHD_DEV_RANGE_END:
  		case IVHD_DEV_ALIAS:
  		case IVHD_DEV_EXT_SELECT:

  			/* all the above subfield types refer to device ids */

  			update_last_devid(dev->devid);

  			break;
  		default:
  			break;
  		}

  		p += ivhd_entry_length(p);

  	}
  
  	WARN_ON(p != end);
  
  	return 0;
  }

  static int __init check_ivrs_checksum(struct acpi_table_header *table)
  {
  	int i;
  	u8 checksum = 0, *p = (u8 *)table;
  
  	for (i = 0; i < table->length; ++i)
  		checksum += p[i];
  	if (checksum != 0) {
  		/* ACPI table corrupt */
  		pr_err(FW_BUG "AMD-Vi: IVRS invalid checksum
  ");
  		return -ENODEV;
  	}
  
  	return 0;
  }

  /*
   * Iterate over all IVHD entries in the ACPI table and find the highest device
   * id which we need to handle. This is the first of three functions which parse
   * the ACPI table. So we check the checksum here.
   */

  static int __init find_last_devid_acpi(struct acpi_table_header *table)
  {

  	u8 *p = (u8 *)table, *end = (u8 *)table;

  	struct ivhd_header *h;

  	p += IVRS_HEADER_LENGTH;
  
  	end += table->length;
  	while (p < end) {
  		h = (struct ivhd_header *)p;

  		if (h->type == amd_iommu_target_ivhd_type) {
  			int ret = find_last_devid_from_ivhd(h);
  
  			if (ret)
  				return ret;

  		}
  		p += h->length;
  	}
  	WARN_ON(p != end);
  
  	return 0;
  }

  /****************************************************************************
   *

   * The following functions belong to the code path which parses the ACPI table

   * the second time. In this ACPI parsing iteration we allocate IOMMU specific
   * data structures, initialize the device/alias/rlookup table and also
   * basically initialize the hardware.
   *
   ****************************************************************************/
  
  /*
   * Allocates the command buffer. This buffer is per AMD IOMMU. We can
   * write commands to that buffer later and the IOMMU will execute them
   * asynchronously
   */

  static int __init alloc_command_buffer(struct amd_iommu *iommu)

  {

  	iommu->cmd_buf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
  						  get_order(CMD_BUFFER_SIZE));

  	return iommu->cmd_buf ? 0 : -ENOMEM;

  }
  
  /*

   * This function resets the command buffer if the IOMMU stopped fetching
   * commands from it.
   */
  void amd_iommu_reset_cmd_buffer(struct amd_iommu *iommu)
  {
  	iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
  
  	writel(0x00, iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
  	writel(0x00, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
  
  	iommu_feature_enable(iommu, CONTROL_CMDBUF_EN);
  }
  
  /*

   * This function writes the command buffer address to the hardware and
   * enables it.
   */
  static void iommu_enable_command_buffer(struct amd_iommu *iommu)
  {
  	u64 entry;
  
  	BUG_ON(iommu->cmd_buf == NULL);
  
  	entry = (u64)virt_to_phys(iommu->cmd_buf);

  	entry |= MMIO_CMD_SIZE_512;

  	memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,

  		    &entry, sizeof(entry));

  	amd_iommu_reset_cmd_buffer(iommu);

  }
  
  static void __init free_command_buffer(struct amd_iommu *iommu)
  {

  	free_pages((unsigned long)iommu->cmd_buf, get_order(CMD_BUFFER_SIZE));

  }

  /* allocates the memory where the IOMMU will log its events to */

  static int __init alloc_event_buffer(struct amd_iommu *iommu)

  {

  	iommu->evt_buf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
  						  get_order(EVT_BUFFER_SIZE));

  	return iommu->evt_buf ? 0 : -ENOMEM;

  }
  
  static void iommu_enable_event_buffer(struct amd_iommu *iommu)
  {
  	u64 entry;
  
  	BUG_ON(iommu->evt_buf == NULL);

  	entry = (u64)virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;

  	memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
  		    &entry, sizeof(entry));

  	/* set head and tail to zero manually */
  	writel(0x00, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
  	writel(0x00, iommu->mmio_base + MMIO_EVT_TAIL_OFFSET);

  	iommu_feature_enable(iommu, CONTROL_EVT_LOG_EN);

  }
  
  static void __init free_event_buffer(struct amd_iommu *iommu)
  {
  	free_pages((unsigned long)iommu->evt_buf, get_order(EVT_BUFFER_SIZE));
  }

  /* allocates the memory where the IOMMU will log its events to */

  static int __init alloc_ppr_log(struct amd_iommu *iommu)

  {

  	iommu->ppr_log = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
  						  get_order(PPR_LOG_SIZE));

  	return iommu->ppr_log ? 0 : -ENOMEM;

  }
  
  static void iommu_enable_ppr_log(struct amd_iommu *iommu)
  {
  	u64 entry;
  
  	if (iommu->ppr_log == NULL)
  		return;
  
  	entry = (u64)virt_to_phys(iommu->ppr_log) | PPR_LOG_SIZE_512;
  
  	memcpy_toio(iommu->mmio_base + MMIO_PPR_LOG_OFFSET,
  		    &entry, sizeof(entry));
  
  	/* set head and tail to zero manually */
  	writel(0x00, iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);
  	writel(0x00, iommu->mmio_base + MMIO_PPR_TAIL_OFFSET);
  
  	iommu_feature_enable(iommu, CONTROL_PPFLOG_EN);
  	iommu_feature_enable(iommu, CONTROL_PPR_EN);
  }
  
  static void __init free_ppr_log(struct amd_iommu *iommu)
  {
  	if (iommu->ppr_log == NULL)
  		return;
  
  	free_pages((unsigned long)iommu->ppr_log, get_order(PPR_LOG_SIZE));
  }

  static void free_ga_log(struct amd_iommu *iommu)
  {
  #ifdef CONFIG_IRQ_REMAP
  	if (iommu->ga_log)
  		free_pages((unsigned long)iommu->ga_log,
  			    get_order(GA_LOG_SIZE));
  	if (iommu->ga_log_tail)
  		free_pages((unsigned long)iommu->ga_log_tail,
  			    get_order(8));
  #endif
  }
  
  static int iommu_ga_log_enable(struct amd_iommu *iommu)
  {
  #ifdef CONFIG_IRQ_REMAP
  	u32 status, i;
  
  	if (!iommu->ga_log)
  		return -EINVAL;
  
  	status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
  
  	/* Check if already running */
  	if (status & (MMIO_STATUS_GALOG_RUN_MASK))
  		return 0;
  
  	iommu_feature_enable(iommu, CONTROL_GAINT_EN);
  	iommu_feature_enable(iommu, CONTROL_GALOG_EN);
  
  	for (i = 0; i < LOOP_TIMEOUT; ++i) {
  		status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
  		if (status & (MMIO_STATUS_GALOG_RUN_MASK))
  			break;
  	}
  
  	if (i >= LOOP_TIMEOUT)
  		return -EINVAL;
  #endif /* CONFIG_IRQ_REMAP */
  	return 0;
  }
  
  #ifdef CONFIG_IRQ_REMAP
  static int iommu_init_ga_log(struct amd_iommu *iommu)
  {
  	u64 entry;
  
  	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
  		return 0;
  
  	iommu->ga_log = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
  					get_order(GA_LOG_SIZE));
  	if (!iommu->ga_log)
  		goto err_out;
  
  	iommu->ga_log_tail = (u8 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
  					get_order(8));
  	if (!iommu->ga_log_tail)
  		goto err_out;
  
  	entry = (u64)virt_to_phys(iommu->ga_log) | GA_LOG_SIZE_512;
  	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_BASE_OFFSET,
  		    &entry, sizeof(entry));
  	entry = ((u64)virt_to_phys(iommu->ga_log) & 0xFFFFFFFFFFFFFULL) & ~7ULL;
  	memcpy_toio(iommu->mmio_base + MMIO_GA_LOG_TAIL_OFFSET,
  		    &entry, sizeof(entry));
  	writel(0x00, iommu->mmio_base + MMIO_GA_HEAD_OFFSET);
  	writel(0x00, iommu->mmio_base + MMIO_GA_TAIL_OFFSET);
  
  	return 0;
  err_out:
  	free_ga_log(iommu);
  	return -EINVAL;
  }
  #endif /* CONFIG_IRQ_REMAP */
  
  static int iommu_init_ga(struct amd_iommu *iommu)
  {
  	int ret = 0;
  
  #ifdef CONFIG_IRQ_REMAP
  	/* Note: We have already checked GASup from IVRS table.
  	 *       Now, we need to make sure that GAMSup is set.
  	 */
  	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
  	    !iommu_feature(iommu, FEATURE_GAM_VAPIC))
  		amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY_GA;
  
  	ret = iommu_init_ga_log(iommu);
  #endif /* CONFIG_IRQ_REMAP */
  
  	return ret;
  }

  static void iommu_enable_gt(struct amd_iommu *iommu)
  {
  	if (!iommu_feature(iommu, FEATURE_GT))
  		return;
  
  	iommu_feature_enable(iommu, CONTROL_GT_EN);
  }

  /* sets a specific bit in the device table entry. */

  static void set_dev_entry_bit(u16 devid, u8 bit)
  {

  	int i = (bit >> 6) & 0x03;
  	int _bit = bit & 0x3f;

  	amd_iommu_dev_table[devid].data[i] |= (1UL << _bit);

  }

  static int get_dev_entry_bit(u16 devid, u8 bit)
  {

  	int i = (bit >> 6) & 0x03;
  	int _bit = bit & 0x3f;

  	return (amd_iommu_dev_table[devid].data[i] & (1UL << _bit)) >> _bit;

  }
  
  
  void amd_iommu_apply_erratum_63(u16 devid)
  {
  	int sysmgt;
  
  	sysmgt = get_dev_entry_bit(devid, DEV_ENTRY_SYSMGT1) |
  		 (get_dev_entry_bit(devid, DEV_ENTRY_SYSMGT2) << 1);
  
  	if (sysmgt == 0x01)
  		set_dev_entry_bit(devid, DEV_ENTRY_IW);
  }

  /* Writes the specific IOMMU for a device into the rlookup table */
  static void __init set_iommu_for_device(struct amd_iommu *iommu, u16 devid)
  {
  	amd_iommu_rlookup_table[devid] = iommu;
  }

  /*
   * This function takes the device specific flags read from the ACPI
   * table and sets up the device table entry with that information
   */

  static void __init set_dev_entry_from_acpi(struct amd_iommu *iommu,
  					   u16 devid, u32 flags, u32 ext_flags)

  {
  	if (flags & ACPI_DEVFLAG_INITPASS)
  		set_dev_entry_bit(devid, DEV_ENTRY_INIT_PASS);
  	if (flags & ACPI_DEVFLAG_EXTINT)
  		set_dev_entry_bit(devid, DEV_ENTRY_EINT_PASS);
  	if (flags & ACPI_DEVFLAG_NMI)
  		set_dev_entry_bit(devid, DEV_ENTRY_NMI_PASS);
  	if (flags & ACPI_DEVFLAG_SYSMGT1)
  		set_dev_entry_bit(devid, DEV_ENTRY_SYSMGT1);
  	if (flags & ACPI_DEVFLAG_SYSMGT2)
  		set_dev_entry_bit(devid, DEV_ENTRY_SYSMGT2);
  	if (flags & ACPI_DEVFLAG_LINT0)
  		set_dev_entry_bit(devid, DEV_ENTRY_LINT0_PASS);
  	if (flags & ACPI_DEVFLAG_LINT1)
  		set_dev_entry_bit(devid, DEV_ENTRY_LINT1_PASS);

  	amd_iommu_apply_erratum_63(devid);

  	set_iommu_for_device(iommu, devid);

  }

  static int __init add_special_device(u8 type, u8 id, u16 *devid, bool cmd_line)

  {
  	struct devid_map *entry;
  	struct list_head *list;

  	if (type == IVHD_SPECIAL_IOAPIC)
  		list = &ioapic_map;
  	else if (type == IVHD_SPECIAL_HPET)
  		list = &hpet_map;
  	else

  		return -EINVAL;

  	list_for_each_entry(entry, list, list) {
  		if (!(entry->id == id && entry->cmd_line))
  			continue;
  
  		pr_info("AMD-Vi: Command-line override present for %s id %d - ignoring
  ",
  			type == IVHD_SPECIAL_IOAPIC ? "IOAPIC" : "HPET", id);

  		*devid = entry->devid;

  		return 0;
  	}

  	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  	if (!entry)
  		return -ENOMEM;

  	entry->id	= id;

  	entry->devid	= *devid;

  	entry->cmd_line	= cmd_line;

  
  	list_add_tail(&entry->list, list);
  
  	return 0;
  }

  static int __init add_acpi_hid_device(u8 *hid, u8 *uid, u16 *devid,
  				      bool cmd_line)
  {
  	struct acpihid_map_entry *entry;
  	struct list_head *list = &acpihid_map;
  
  	list_for_each_entry(entry, list, list) {
  		if (strcmp(entry->hid, hid) ||
  		    (*uid && *entry->uid && strcmp(entry->uid, uid)) ||
  		    !entry->cmd_line)
  			continue;
  
  		pr_info("AMD-Vi: Command-line override for hid:%s uid:%s
  ",
  			hid, uid);
  		*devid = entry->devid;
  		return 0;
  	}
  
  	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  	if (!entry)
  		return -ENOMEM;
  
  	memcpy(entry->uid, uid, strlen(uid));
  	memcpy(entry->hid, hid, strlen(hid));
  	entry->devid = *devid;
  	entry->cmd_line	= cmd_line;
  	entry->root_devid = (entry->devid & (~0x7));
  
  	pr_info("AMD-Vi:%s, add hid:%s, uid:%s, rdevid:%d
  ",
  		entry->cmd_line ? "cmd" : "ivrs",
  		entry->hid, entry->uid, entry->root_devid);
  
  	list_add_tail(&entry->list, list);
  	return 0;
  }

  static int __init add_early_maps(void)
  {
  	int i, ret;
  
  	for (i = 0; i < early_ioapic_map_size; ++i) {
  		ret = add_special_device(IVHD_SPECIAL_IOAPIC,
  					 early_ioapic_map[i].id,

  					 &early_ioapic_map[i].devid,

  					 early_ioapic_map[i].cmd_line);
  		if (ret)
  			return ret;
  	}
  
  	for (i = 0; i < early_hpet_map_size; ++i) {
  		ret = add_special_device(IVHD_SPECIAL_HPET,
  					 early_hpet_map[i].id,

  					 &early_hpet_map[i].devid,

  					 early_hpet_map[i].cmd_line);
  		if (ret)
  			return ret;
  	}

  	for (i = 0; i < early_acpihid_map_size; ++i) {
  		ret = add_acpi_hid_device(early_acpihid_map[i].hid,
  					  early_acpihid_map[i].uid,
  					  &early_acpihid_map[i].devid,
  					  early_acpihid_map[i].cmd_line);
  		if (ret)
  			return ret;
  	}

  	return 0;
  }

  /*

   * Reads the device exclusion range from ACPI and initializes the IOMMU with

   * it
   */

  static void __init set_device_exclusion_range(u16 devid, struct ivmd_header *m)
  {
  	struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
  
  	if (!(m->flags & IVMD_FLAG_EXCL_RANGE))
  		return;
  
  	if (iommu) {

  		/*
  		 * We only can configure exclusion ranges per IOMMU, not
  		 * per device. But we can enable the exclusion range per
  		 * device. This is done here
  		 */

  		set_dev_entry_bit(devid, DEV_ENTRY_EX);

  		iommu->exclusion_start = m->range_start;
  		iommu->exclusion_length = m->range_length;
  	}
  }

  /*

   * Takes a pointer to an AMD IOMMU entry in the ACPI table and
   * initializes the hardware and our data structures with it.
   */

  static int __init init_iommu_from_acpi(struct amd_iommu *iommu,

  					struct ivhd_header *h)
  {
  	u8 *p = (u8 *)h;
  	u8 *end = p, flags = 0;

  	u16 devid = 0, devid_start = 0, devid_to = 0;
  	u32 dev_i, ext_flags = 0;

  	bool alias = false;

  	struct ivhd_entry *e;

  	u32 ivhd_size;

  	int ret;
  
  
  	ret = add_early_maps();
  	if (ret)
  		return ret;

  
  	/*

  	 * First save the recommended feature enable bits from ACPI

  	 */

  	iommu->acpi_flags = h->flags;

  
  	/*
  	 * Done. Now parse the device entries
  	 */

  	ivhd_size = get_ivhd_header_size(h);
  	if (!ivhd_size) {
  		pr_err("AMD-Vi: Unsupported IVHD type %#x
  ", h->type);
  		return -EINVAL;
  	}
  
  	p += ivhd_size;

  	end += h->length;

  	while (p < end) {
  		e = (struct ivhd_entry *)p;
  		switch (e->type) {
  		case IVHD_DEV_ALL:

  			DUMP_printk("  DEV_ALL\t\t\tflags: %02x
  ", e->flags);

  			for (dev_i = 0; dev_i <= amd_iommu_last_bdf; ++dev_i)
  				set_dev_entry_from_acpi(iommu, dev_i, e->flags, 0);

  			break;
  		case IVHD_DEV_SELECT:

  
  			DUMP_printk("  DEV_SELECT\t\t\t devid: %02x:%02x.%x "
  				    "flags: %02x
  ",

  				    PCI_BUS_NUM(e->devid),

  				    PCI_SLOT(e->devid),
  				    PCI_FUNC(e->devid),
  				    e->flags);

  			devid = e->devid;

  			set_dev_entry_from_acpi(iommu, devid, e->flags, 0);

  			break;
  		case IVHD_DEV_SELECT_RANGE_START:

  
  			DUMP_printk("  DEV_SELECT_RANGE_START\t "
  				    "devid: %02x:%02x.%x flags: %02x
  ",

  				    PCI_BUS_NUM(e->devid),

  				    PCI_SLOT(e->devid),
  				    PCI_FUNC(e->devid),
  				    e->flags);

  			devid_start = e->devid;
  			flags = e->flags;
  			ext_flags = 0;

  			alias = false;

  			break;
  		case IVHD_DEV_ALIAS:

  
  			DUMP_printk("  DEV_ALIAS\t\t\t devid: %02x:%02x.%x "
  				    "flags: %02x devid_to: %02x:%02x.%x
  ",

  				    PCI_BUS_NUM(e->devid),

  				    PCI_SLOT(e->devid),
  				    PCI_FUNC(e->devid),
  				    e->flags,

  				    PCI_BUS_NUM(e->ext >> 8),

  				    PCI_SLOT(e->ext >> 8),
  				    PCI_FUNC(e->ext >> 8));

  			devid = e->devid;
  			devid_to = e->ext >> 8;

  			set_dev_entry_from_acpi(iommu, devid   , e->flags, 0);

  			set_dev_entry_from_acpi(iommu, devid_to, e->flags, 0);

  			amd_iommu_alias_table[devid] = devid_to;
  			break;
  		case IVHD_DEV_ALIAS_RANGE:

  
  			DUMP_printk("  DEV_ALIAS_RANGE\t\t "
  				    "devid: %02x:%02x.%x flags: %02x "
  				    "devid_to: %02x:%02x.%x
  ",

  				    PCI_BUS_NUM(e->devid),

  				    PCI_SLOT(e->devid),
  				    PCI_FUNC(e->devid),
  				    e->flags,

  				    PCI_BUS_NUM(e->ext >> 8),

  				    PCI_SLOT(e->ext >> 8),
  				    PCI_FUNC(e->ext >> 8));

  			devid_start = e->devid;
  			flags = e->flags;
  			devid_to = e->ext >> 8;
  			ext_flags = 0;

  			alias = true;

  			break;
  		case IVHD_DEV_EXT_SELECT:

  
  			DUMP_printk("  DEV_EXT_SELECT\t\t devid: %02x:%02x.%x "
  				    "flags: %02x ext: %08x
  ",

  				    PCI_BUS_NUM(e->devid),

  				    PCI_SLOT(e->devid),
  				    PCI_FUNC(e->devid),
  				    e->flags, e->ext);

  			devid = e->devid;

  			set_dev_entry_from_acpi(iommu, devid, e->flags,
  						e->ext);

  			break;
  		case IVHD_DEV_EXT_SELECT_RANGE:

  
  			DUMP_printk("  DEV_EXT_SELECT_RANGE\t devid: "
  				    "%02x:%02x.%x flags: %02x ext: %08x
  ",

  				    PCI_BUS_NUM(e->devid),

  				    PCI_SLOT(e->devid),
  				    PCI_FUNC(e->devid),
  				    e->flags, e->ext);

  			devid_start = e->devid;
  			flags = e->flags;
  			ext_flags = e->ext;

  			alias = false;

  			break;
  		case IVHD_DEV_RANGE_END:

  
  			DUMP_printk("  DEV_RANGE_END\t\t devid: %02x:%02x.%x
  ",

  				    PCI_BUS_NUM(e->devid),

  				    PCI_SLOT(e->devid),
  				    PCI_FUNC(e->devid));

  			devid = e->devid;
  			for (dev_i = devid_start; dev_i <= devid; ++dev_i) {

  				if (alias) {

  					amd_iommu_alias_table[dev_i] = devid_to;

  					set_dev_entry_from_acpi(iommu,
  						devid_to, flags, ext_flags);
  				}
  				set_dev_entry_from_acpi(iommu, dev_i,
  							flags, ext_flags);

  			}
  			break;

  		case IVHD_DEV_SPECIAL: {
  			u8 handle, type;
  			const char *var;
  			u16 devid;
  			int ret;
  
  			handle = e->ext & 0xff;
  			devid  = (e->ext >>  8) & 0xffff;
  			type   = (e->ext >> 24) & 0xff;
  
  			if (type == IVHD_SPECIAL_IOAPIC)
  				var = "IOAPIC";
  			else if (type == IVHD_SPECIAL_HPET)
  				var = "HPET";
  			else
  				var = "UNKNOWN";
  
  			DUMP_printk("  DEV_SPECIAL(%s[%d])\t\tdevid: %02x:%02x.%x
  ",
  				    var, (int)handle,

  				    PCI_BUS_NUM(devid),

  				    PCI_SLOT(devid),
  				    PCI_FUNC(devid));

  			ret = add_special_device(type, handle, &devid, false);

  			if (ret)
  				return ret;

  
  			/*
  			 * add_special_device might update the devid in case a
  			 * command-line override is present. So call
  			 * set_dev_entry_from_acpi after add_special_device.
  			 */
  			set_dev_entry_from_acpi(iommu, devid, e->flags, 0);

  			break;
  		}

  		case IVHD_DEV_ACPI_HID: {
  			u16 devid;
  			u8 hid[ACPIHID_HID_LEN] = {0};
  			u8 uid[ACPIHID_UID_LEN] = {0};
  			int ret;
  
  			if (h->type != 0x40) {
  				pr_err(FW_BUG "Invalid IVHD device type %#x
  ",
  				       e->type);
  				break;
  			}
  
  			memcpy(hid, (u8 *)(&e->ext), ACPIHID_HID_LEN - 1);
  			hid[ACPIHID_HID_LEN - 1] = '\0';
  
  			if (!(*hid)) {
  				pr_err(FW_BUG "Invalid HID.
  ");
  				break;
  			}
  
  			switch (e->uidf) {
  			case UID_NOT_PRESENT:
  
  				if (e->uidl != 0)
  					pr_warn(FW_BUG "Invalid UID length.
  ");
  
  				break;
  			case UID_IS_INTEGER:
  
  				sprintf(uid, "%d", e->uid);
  
  				break;
  			case UID_IS_CHARACTER:
  
  				memcpy(uid, (u8 *)(&e->uid), ACPIHID_UID_LEN - 1);
  				uid[ACPIHID_UID_LEN - 1] = '\0';
  
  				break;
  			default:
  				break;
  			}

  			devid = e->devid;

  			DUMP_printk("  DEV_ACPI_HID(%s[%s])\t\tdevid: %02x:%02x.%x
  ",
  				    hid, uid,
  				    PCI_BUS_NUM(devid),
  				    PCI_SLOT(devid),
  				    PCI_FUNC(devid));

  			flags = e->flags;
  
  			ret = add_acpi_hid_device(hid, uid, &devid, false);
  			if (ret)
  				return ret;
  
  			/*
  			 * add_special_device might update the devid in case a
  			 * command-line override is present. So call
  			 * set_dev_entry_from_acpi after add_special_device.
  			 */
  			set_dev_entry_from_acpi(iommu, devid, e->flags, 0);
  
  			break;
  		}

  		default:
  			break;
  		}

  		p += ivhd_entry_length(p);

  	}

  
  	return 0;

  }

  static void __init free_iommu_one(struct amd_iommu *iommu)
  {
  	free_command_buffer(iommu);

  	free_event_buffer(iommu);

  	free_ppr_log(iommu);

  	free_ga_log(iommu);

  	iommu_unmap_mmio_space(iommu);
  }
  
  static void __init free_iommu_all(void)
  {
  	struct amd_iommu *iommu, *next;

  	for_each_iommu_safe(iommu, next) {

  		list_del(&iommu->list);
  		free_iommu_one(iommu);
  		kfree(iommu);
  	}
  }

  /*

   * Family15h Model 10h-1fh erratum 746 (IOMMU Logging May Stall Translations)
   * Workaround:
   *     BIOS should disable L2B micellaneous clock gating by setting
   *     L2_L2B_CK_GATE_CONTROL[CKGateL2BMiscDisable](D0F2xF4_x90[2]) = 1b
   */

  static void amd_iommu_erratum_746_workaround(struct amd_iommu *iommu)

  {
  	u32 value;
  
  	if ((boot_cpu_data.x86 != 0x15) ||
  	    (boot_cpu_data.x86_model < 0x10) ||
  	    (boot_cpu_data.x86_model > 0x1f))
  		return;
  
  	pci_write_config_dword(iommu->dev, 0xf0, 0x90);
  	pci_read_config_dword(iommu->dev, 0xf4, &value);
  
  	if (value & BIT(2))
  		return;
  
  	/* Select NB indirect register 0x90 and enable writing */
  	pci_write_config_dword(iommu->dev, 0xf0, 0x90 | (1 << 8));
  
  	pci_write_config_dword(iommu->dev, 0xf4, value | 0x4);
  	pr_info("AMD-Vi: Applying erratum 746 workaround for IOMMU at %s
  ",
  		dev_name(&iommu->dev->dev));
  
  	/* Clear the enable writing bit */
  	pci_write_config_dword(iommu->dev, 0xf0, 0x90);
  }
  
  /*

   * Family15h Model 30h-3fh (IOMMU Mishandles ATS Write Permission)
   * Workaround:
   *     BIOS should enable ATS write permission check by setting
   *     L2_DEBUG_3[AtsIgnoreIWDis](D0F2xF4_x47[0]) = 1b
   */
  static void amd_iommu_ats_write_check_workaround(struct amd_iommu *iommu)
  {
  	u32 value;
  
  	if ((boot_cpu_data.x86 != 0x15) ||
  	    (boot_cpu_data.x86_model < 0x30) ||
  	    (boot_cpu_data.x86_model > 0x3f))
  		return;
  
  	/* Test L2_DEBUG_3[AtsIgnoreIWDis] == 1 */
  	value = iommu_read_l2(iommu, 0x47);
  
  	if (value & BIT(0))
  		return;
  
  	/* Set L2_DEBUG_3[AtsIgnoreIWDis] = 1 */
  	iommu_write_l2(iommu, 0x47, value | BIT(0));
  
  	pr_info("AMD-Vi: Applying ATS write check workaround for IOMMU at %s
  ",
  		dev_name(&iommu->dev->dev));
  }
  
  /*

   * This function clues the initialization function for one IOMMU
   * together and also allocates the command buffer and programs the
   * hardware. It does NOT enable the IOMMU. This is done afterwards.
   */

  static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
  {

  	int ret;

  	spin_lock_init(&iommu->lock);

  
  	/* Add IOMMU to internal data structures */

  	list_add_tail(&iommu->list, &amd_iommu_list);

  	iommu->index             = amd_iommus_present++;
  
  	if (unlikely(iommu->index >= MAX_IOMMUS)) {
  		WARN(1, "AMD-Vi: System has more IOMMUs than supported by this driver
  ");
  		return -ENOSYS;
  	}
  
  	/* Index is fine - add IOMMU to the array */
  	amd_iommus[iommu->index] = iommu;

  
  	/*
  	 * Copy data from ACPI table entry to the iommu struct
  	 */

  	iommu->devid   = h->devid;

  	iommu->cap_ptr = h->cap_ptr;

  	iommu->pci_seg = h->pci_seg;

  	iommu->mmio_phys = h->mmio_phys;

  	switch (h->type) {
  	case 0x10:
  		/* Check if IVHD EFR contains proper max banks/counters */
  		if ((h->efr_attr != 0) &&
  		    ((h->efr_attr & (0xF << 13)) != 0) &&
  		    ((h->efr_attr & (0x3F << 17)) != 0))
  			iommu->mmio_phys_end = MMIO_REG_END_OFFSET;
  		else
  			iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;

  		if (((h->efr_attr & (0x1 << IOMMU_FEAT_GASUP_SHIFT)) == 0))
  			amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;

  		break;
  	case 0x11:
  	case 0x40:
  		if (h->efr_reg & (1 << 9))
  			iommu->mmio_phys_end = MMIO_REG_END_OFFSET;
  		else
  			iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;

  		if (((h->efr_reg & (0x1 << IOMMU_EFR_GASUP_SHIFT)) == 0))
  			amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;

  		break;
  	default:
  		return -EINVAL;

  	}
  
  	iommu->mmio_base = iommu_map_mmio_space(iommu->mmio_phys,
  						iommu->mmio_phys_end);

  	if (!iommu->mmio_base)
  		return -ENOMEM;

  	if (alloc_command_buffer(iommu))

  		return -ENOMEM;

  	if (alloc_event_buffer(iommu))

  		return -ENOMEM;

  	iommu->int_enabled = false;

  	ret = init_iommu_from_acpi(iommu, h);
  	if (ret)
  		return ret;

  	ret = amd_iommu_create_irq_domain(iommu);
  	if (ret)
  		return ret;

  	/*
  	 * Make sure IOMMU is not considered to translate itself. The IVRS
  	 * table tells us so, but this is a lie!
  	 */
  	amd_iommu_rlookup_table[iommu->devid] = NULL;

  	return 0;

  }

  /**
   * get_highest_supported_ivhd_type - Look up the appropriate IVHD type
   * @ivrs          Pointer to the IVRS header
   *
   * This function search through all IVDB of the maximum supported IVHD
   */
  static u8 get_highest_supported_ivhd_type(struct acpi_table_header *ivrs)
  {
  	u8 *base = (u8 *)ivrs;
  	struct ivhd_header *ivhd = (struct ivhd_header *)
  					(base + IVRS_HEADER_LENGTH);
  	u8 last_type = ivhd->type;
  	u16 devid = ivhd->devid;
  
  	while (((u8 *)ivhd - base < ivrs->length) &&
  	       (ivhd->type <= ACPI_IVHD_TYPE_MAX_SUPPORTED)) {
  		u8 *p = (u8 *) ivhd;
  
  		if (ivhd->devid == devid)
  			last_type = ivhd->type;
  		ivhd = (struct ivhd_header *)(p + ivhd->length);
  	}
  
  	return last_type;
  }

  /*
   * Iterates over all IOMMU entries in the ACPI table, allocates the
   * IOMMU structure and initializes it with init_iommu_one()
   */

  static int __init init_iommu_all(struct acpi_table_header *table)
  {
  	u8 *p = (u8 *)table, *end = (u8 *)table;
  	struct ivhd_header *h;
  	struct amd_iommu *iommu;
  	int ret;

  	end += table->length;
  	p += IVRS_HEADER_LENGTH;
  
  	while (p < end) {
  		h = (struct ivhd_header *)p;

  		if (*p == amd_iommu_target_ivhd_type) {

  			DUMP_printk("device: %02x:%02x.%01x cap: %04x "

  				    "seg: %d flags: %01x info %04x
  ",

  				    PCI_BUS_NUM(h->devid), PCI_SLOT(h->devid),

  				    PCI_FUNC(h->devid), h->cap_ptr,
  				    h->pci_seg, h->flags, h->info);
  			DUMP_printk("       mmio-addr: %016llx
  ",
  				    h->mmio_phys);

  			iommu = kzalloc(sizeof(struct amd_iommu), GFP_KERNEL);

  			if (iommu == NULL)
  				return -ENOMEM;

  			ret = init_iommu_one(iommu, h);

  			if (ret)
  				return ret;

  		}
  		p += h->length;
  
  	}
  	WARN_ON(p != end);
  
  	return 0;
  }

  
  static void init_iommu_perf_ctr(struct amd_iommu *iommu)
  {
  	u64 val = 0xabcd, val2 = 0;
  
  	if (!iommu_feature(iommu, FEATURE_PC))
  		return;
  
  	amd_iommu_pc_present = true;
  
  	/* Check if the performance counters can be written to */

  	if ((0 != iommu_pc_get_set_reg_val(iommu, 0, 0, 0, &val, true)) ||
  	    (0 != iommu_pc_get_set_reg_val(iommu, 0, 0, 0, &val2, false)) ||

  	    (val != val2)) {
  		pr_err("AMD-Vi: Unable to write to IOMMU perf counter.
  ");
  		amd_iommu_pc_present = false;
  		return;
  	}
  
  	pr_info("AMD-Vi: IOMMU performance counters supported
  ");
  
  	val = readl(iommu->mmio_base + MMIO_CNTR_CONF_OFFSET);
  	iommu->max_banks = (u8) ((val >> 12) & 0x3f);
  	iommu->max_counters = (u8) ((val >> 7) & 0xf);
  }

  static ssize_t amd_iommu_show_cap(struct device *dev,
  				  struct device_attribute *attr,
  				  char *buf)
  {
  	struct amd_iommu *iommu = dev_get_drvdata(dev);
  	return sprintf(buf, "%x
  ", iommu->cap);
  }
  static DEVICE_ATTR(cap, S_IRUGO, amd_iommu_show_cap, NULL);
  
  static ssize_t amd_iommu_show_features(struct device *dev,
  				       struct device_attribute *attr,
  				       char *buf)
  {
  	struct amd_iommu *iommu = dev_get_drvdata(dev);
  	return sprintf(buf, "%llx
  ", iommu->features);
  }
  static DEVICE_ATTR(features, S_IRUGO, amd_iommu_show_features, NULL);
  
  static struct attribute *amd_iommu_attrs[] = {
  	&dev_attr_cap.attr,
  	&dev_attr_features.attr,
  	NULL,
  };
  
  static struct attribute_group amd_iommu_group = {
  	.name = "amd-iommu",
  	.attrs = amd_iommu_attrs,
  };
  
  static const struct attribute_group *amd_iommu_groups[] = {
  	&amd_iommu_group,
  	NULL,
  };

  static int iommu_init_pci(struct amd_iommu *iommu)
  {
  	int cap_ptr = iommu->cap_ptr;
  	u32 range, misc, low, high;

  	int ret;

  	iommu->dev = pci_get_bus_and_slot(PCI_BUS_NUM(iommu->devid),

  					  iommu->devid & 0xff);
  	if (!iommu->dev)
  		return -ENODEV;

  	/* Prevent binding other PCI device drivers to IOMMU devices */
  	iommu->dev->match_driver = false;

  	pci_read_config_dword(iommu->dev, cap_ptr + MMIO_CAP_HDR_OFFSET,
  			      &iommu->cap);
  	pci_read_config_dword(iommu->dev, cap_ptr + MMIO_RANGE_OFFSET,
  			      &range);
  	pci_read_config_dword(iommu->dev, cap_ptr + MMIO_MISC_OFFSET,
  			      &misc);

  	if (!(iommu->cap & (1 << IOMMU_CAP_IOTLB)))
  		amd_iommu_iotlb_sup = false;
  
  	/* read extended feature bits */
  	low  = readl(iommu->mmio_base + MMIO_EXT_FEATURES);
  	high = readl(iommu->mmio_base + MMIO_EXT_FEATURES + 4);
  
  	iommu->features = ((u64)high << 32) | low;
  
  	if (iommu_feature(iommu, FEATURE_GT)) {
  		int glxval;

  		u32 max_pasid;
  		u64 pasmax;

  		pasmax = iommu->features & FEATURE_PASID_MASK;
  		pasmax >>= FEATURE_PASID_SHIFT;
  		max_pasid  = (1 << (pasmax + 1)) - 1;

  		amd_iommu_max_pasid = min(amd_iommu_max_pasid, max_pasid);
  
  		BUG_ON(amd_iommu_max_pasid & ~PASID_MASK);

  
  		glxval   = iommu->features & FEATURE_GLXVAL_MASK;
  		glxval >>= FEATURE_GLXVAL_SHIFT;
  
  		if (amd_iommu_max_glx_val == -1)
  			amd_iommu_max_glx_val = glxval;
  		else
  			amd_iommu_max_glx_val = min(amd_iommu_max_glx_val, glxval);
  	}
  
  	if (iommu_feature(iommu, FEATURE_GT) &&
  	    iommu_feature(iommu, FEATURE_PPR)) {
  		iommu->is_iommu_v2   = true;
  		amd_iommu_v2_present = true;
  	}

  	if (iommu_feature(iommu, FEATURE_PPR) && alloc_ppr_log(iommu))
  		return -ENOMEM;

  	ret = iommu_init_ga(iommu);
  	if (ret)
  		return ret;

  	if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE))
  		amd_iommu_np_cache = true;

  	init_iommu_perf_ctr(iommu);

  	if (is_rd890_iommu(iommu->dev)) {
  		int i, j;
  
  		iommu->root_pdev = pci_get_bus_and_slot(iommu->dev->bus->number,
  				PCI_DEVFN(0, 0));
  
  		/*
  		 * Some rd890 systems may not be fully reconfigured by the
  		 * BIOS, so it's necessary for us to store this information so
  		 * it can be reprogrammed on resume
  		 */
  		pci_read_config_dword(iommu->dev, iommu->cap_ptr + 4,
  				&iommu->stored_addr_lo);
  		pci_read_config_dword(iommu->dev, iommu->cap_ptr + 8,
  				&iommu->stored_addr_hi);
  
  		/* Low bit locks writes to configuration space */
  		iommu->stored_addr_lo &= ~1;
  
  		for (i = 0; i < 6; i++)
  			for (j = 0; j < 0x12; j++)
  				iommu->stored_l1[i][j] = iommu_read_l1(iommu, i, j);
  
  		for (i = 0; i < 0x83; i++)
  			iommu->stored_l2[i] = iommu_read_l2(iommu, i);
  	}

  	amd_iommu_erratum_746_workaround(iommu);

  	amd_iommu_ats_write_check_workaround(iommu);

  	iommu->iommu_dev = iommu_device_create(&iommu->dev->dev, iommu,
  					       amd_iommu_groups, "ivhd%d",
  					       iommu->index);

  	return pci_enable_device(iommu->dev);
  }

  static void print_iommu_info(void)
  {
  	static const char * const feat_str[] = {
  		"PreF", "PPR", "X2APIC", "NX", "GT", "[5]",
  		"IA", "GA", "HE", "PC"
  	};
  	struct amd_iommu *iommu;
  
  	for_each_iommu(iommu) {
  		int i;
  
  		pr_info("AMD-Vi: Found IOMMU at %s cap 0x%hx
  ",
  			dev_name(&iommu->dev->dev), iommu->cap_ptr);
  
  		if (iommu->cap & (1 << IOMMU_CAP_EFR)) {

  			pr_info("AMD-Vi: Extended features (%#llx):
  ",
  				iommu->features);

  			for (i = 0; i < ARRAY_SIZE(feat_str); ++i) {

  				if (iommu_feature(iommu, (1ULL << i)))
  					pr_cont(" %s", feat_str[i]);
  			}

  
  			if (iommu->features & FEATURE_GAM_VAPIC)
  				pr_cont(" GA_vAPIC");

  			pr_cont("
  ");

  		}

  	}

  	if (irq_remapping_enabled) {

  		pr_info("AMD-Vi: Interrupt remapping enabled
  ");

  		if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
  			pr_info("AMD-Vi: virtual APIC enabled
  ");
  	}

  }

  static int __init amd_iommu_init_pci(void)

  {
  	struct amd_iommu *iommu;
  	int ret = 0;
  
  	for_each_iommu(iommu) {
  		ret = iommu_init_pci(iommu);
  		if (ret)
  			break;
  	}

  	/*
  	 * Order is important here to make sure any unity map requirements are
  	 * fulfilled. The unity mappings are created and written to the device
  	 * table during the amd_iommu_init_api() call.
  	 *
  	 * After that we call init_device_table_dma() to make sure any
  	 * uninitialized DTE will block DMA, and in the end we flush the caches
  	 * of all IOMMUs to make sure the changes to the device table are
  	 * active.
  	 */
  	ret = amd_iommu_init_api();

  	init_device_table_dma();
  
  	for_each_iommu(iommu)
  		iommu_flush_all_caches(iommu);

  	if (!ret)
  		print_iommu_info();

  	return ret;
  }

  /****************************************************************************
   *

   * The following functions initialize the MSI interrupts for all IOMMUs

   * in the system. It's a bit challenging because there could be multiple

   * IOMMUs per PCI BDF but we can call pci_enable_msi(x) only once per
   * pci_dev.
   *
   ****************************************************************************/

  static int iommu_setup_msi(struct amd_iommu *iommu)

  {
  	int r;

  	r = pci_enable_msi(iommu->dev);
  	if (r)
  		return r;

  	r = request_threaded_irq(iommu->dev->irq,
  				 amd_iommu_int_handler,
  				 amd_iommu_int_thread,
  				 0, "AMD-Vi",

  				 iommu);

  
  	if (r) {
  		pci_disable_msi(iommu->dev);

  		return r;

  	}

  	iommu->int_enabled = true;

  	return 0;
  }

  static int iommu_init_msi(struct amd_iommu *iommu)

  {

  	int ret;

  	if (iommu->int_enabled)

  		goto enable_faults;

  	if (iommu->dev->msi_cap)

  		ret = iommu_setup_msi(iommu);
  	else
  		ret = -ENODEV;
  
  	if (ret)
  		return ret;

  enable_faults:
  	iommu_feature_enable(iommu, CONTROL_EVT_INT_EN);

  	if (iommu->ppr_log != NULL)
  		iommu_feature_enable(iommu, CONTROL_PPFINT_EN);

  	iommu_ga_log_enable(iommu);

  	return 0;

  }
  
  /****************************************************************************
   *

   * The next functions belong to the third pass of parsing the ACPI
   * table. In this last pass the memory mapping requirements are

   * gathered (like exclusion and unity mapping ranges).

   *
   ****************************************************************************/

  static void __init free_unity_maps(void)
  {
  	struct unity_map_entry *entry, *next;
  
  	list_for_each_entry_safe(entry, next, &amd_iommu_unity_map, list) {
  		list_del(&entry->list);
  		kfree(entry);
  	}
  }

  /* called when we find an exclusion range definition in ACPI */

  static int __init init_exclusion_range(struct ivmd_header *m)
  {
  	int i;
  
  	switch (m->type) {
  	case ACPI_IVMD_TYPE:
  		set_device_exclusion_range(m->devid, m);
  		break;
  	case ACPI_IVMD_TYPE_ALL:

  		for (i = 0; i <= amd_iommu_last_bdf; ++i)

  			set_device_exclusion_range(i, m);
  		break;
  	case ACPI_IVMD_TYPE_RANGE:
  		for (i = m->devid; i <= m->aux; ++i)
  			set_device_exclusion_range(i, m);
  		break;
  	default:
  		break;
  	}
  
  	return 0;
  }

  /* called for unity map ACPI definition */

  static int __init init_unity_map_range(struct ivmd_header *m)
  {

  	struct unity_map_entry *e = NULL;

  	char *s;

  
  	e = kzalloc(sizeof(*e), GFP_KERNEL);
  	if (e == NULL)
  		return -ENOMEM;
  
  	switch (m->type) {
  	default:

  		kfree(e);
  		return 0;

  	case ACPI_IVMD_TYPE:

  		s = "IVMD_TYPEi\t\t\t";

  		e->devid_start = e->devid_end = m->devid;
  		break;
  	case ACPI_IVMD_TYPE_ALL:

  		s = "IVMD_TYPE_ALL\t\t";

  		e->devid_start = 0;
  		e->devid_end = amd_iommu_last_bdf;
  		break;
  	case ACPI_IVMD_TYPE_RANGE:

  		s = "IVMD_TYPE_RANGE\t\t";

  		e->devid_start = m->devid;
  		e->devid_end = m->aux;
  		break;
  	}
  	e->address_start = PAGE_ALIGN(m->range_start);
  	e->address_end = e->address_start + PAGE_ALIGN(m->range_length);
  	e->prot = m->flags >> 1;

  	DUMP_printk("%s devid_start: %02x:%02x.%x devid_end: %02x:%02x.%x"
  		    " range_start: %016llx range_end: %016llx flags: %x
  ", s,

  		    PCI_BUS_NUM(e->devid_start), PCI_SLOT(e->devid_start),
  		    PCI_FUNC(e->devid_start), PCI_BUS_NUM(e->devid_end),

  		    PCI_SLOT(e->devid_end), PCI_FUNC(e->devid_end),
  		    e->address_start, e->address_end, m->flags);

  	list_add_tail(&e->list, &amd_iommu_unity_map);
  
  	return 0;
  }

  /* iterates over all memory definitions we find in the ACPI table */

  static int __init init_memory_definitions(struct acpi_table_header *table)
  {
  	u8 *p = (u8 *)table, *end = (u8 *)table;
  	struct ivmd_header *m;

  	end += table->length;
  	p += IVRS_HEADER_LENGTH;
  
  	while (p < end) {
  		m = (struct ivmd_header *)p;
  		if (m->flags & IVMD_FLAG_EXCL_RANGE)
  			init_exclusion_range(m);
  		else if (m->flags & IVMD_FLAG_UNITY_MAP)
  			init_unity_map_range(m);
  
  		p += m->length;
  	}
  
  	return 0;
  }

  /*

   * Init the device table to not allow DMA access for devices and
   * suppress all page faults
   */

  static void init_device_table_dma(void)

  {

  	u32 devid;

  
  	for (devid = 0; devid <= amd_iommu_last_bdf; ++devid) {
  		set_dev_entry_bit(devid, DEV_ENTRY_VALID);
  		set_dev_entry_bit(devid, DEV_ENTRY_TRANSLATION);

  	}
  }

  static void __init uninit_device_table_dma(void)
  {
  	u32 devid;
  
  	for (devid = 0; devid <= amd_iommu_last_bdf; ++devid) {
  		amd_iommu_dev_table[devid].data[0] = 0ULL;
  		amd_iommu_dev_table[devid].data[1] = 0ULL;
  	}
  }

  static void init_device_table(void)
  {
  	u32 devid;
  
  	if (!amd_iommu_irq_remap)
  		return;
  
  	for (devid = 0; devid <= amd_iommu_last_bdf; ++devid)
  		set_dev_entry_bit(devid, DEV_ENTRY_IRQ_TBL_EN);
  }

  static void iommu_init_flags(struct amd_iommu *iommu)
  {
  	iommu->acpi_flags & IVHD_FLAG_HT_TUN_EN_MASK ?
  		iommu_feature_enable(iommu, CONTROL_HT_TUN_EN) :
  		iommu_feature_disable(iommu, CONTROL_HT_TUN_EN);
  
  	iommu->acpi_flags & IVHD_FLAG_PASSPW_EN_MASK ?
  		iommu_feature_enable(iommu, CONTROL_PASSPW_EN) :
  		iommu_feature_disable(iommu, CONTROL_PASSPW_EN);
  
  	iommu->acpi_flags & IVHD_FLAG_RESPASSPW_EN_MASK ?
  		iommu_feature_enable(iommu, CONTROL_RESPASSPW_EN) :
  		iommu_feature_disable(iommu, CONTROL_RESPASSPW_EN);
  
  	iommu->acpi_flags & IVHD_FLAG_ISOC_EN_MASK ?
  		iommu_feature_enable(iommu, CONTROL_ISOC_EN) :
  		iommu_feature_disable(iommu, CONTROL_ISOC_EN);
  
  	/*
  	 * make IOMMU memory accesses cache coherent
  	 */
  	iommu_feature_enable(iommu, CONTROL_COHERENT_EN);

  
  	/* Set IOTLB invalidation timeout to 1s */
  	iommu_set_inv_tlb_timeout(iommu, CTRL_INV_TO_1S);

  }

  static void iommu_apply_resume_quirks(struct amd_iommu *iommu)

  {

  	int i, j;
  	u32 ioc_feature_control;

  	struct pci_dev *pdev = iommu->root_pdev;

  
  	/* RD890 BIOSes may not have completely reconfigured the iommu */

  	if (!is_rd890_iommu(iommu->dev) || !pdev)

  		return;
  
  	/*
  	 * First, we need to ensure that the iommu is enabled. This is
  	 * controlled by a register in the northbridge
  	 */

  
  	/* Select Northbridge indirect register 0x75 and enable writing */
  	pci_write_config_dword(pdev, 0x60, 0x75 | (1 << 7));
  	pci_read_config_dword(pdev, 0x64, &ioc_feature_control);
  
  	/* Enable the iommu */
  	if (!(ioc_feature_control & 0x1))
  		pci_write_config_dword(pdev, 0x64, ioc_feature_control | 1);

  	/* Restore the iommu BAR */
  	pci_write_config_dword(iommu->dev, iommu->cap_ptr + 4,
  			       iommu->stored_addr_lo);
  	pci_write_config_dword(iommu->dev, iommu->cap_ptr + 8,
  			       iommu->stored_addr_hi);
  
  	/* Restore the l1 indirect regs for each of the 6 l1s */
  	for (i = 0; i < 6; i++)
  		for (j = 0; j < 0x12; j++)
  			iommu_write_l1(iommu, i, j, iommu->stored_l1[i][j]);
  
  	/* Restore the l2 indirect regs */
  	for (i = 0; i < 0x83; i++)
  		iommu_write_l2(iommu, i, iommu->stored_l2[i]);
  
  	/* Lock PCI setup registers */
  	pci_write_config_dword(iommu->dev, iommu->cap_ptr + 4,
  			       iommu->stored_addr_lo | 1);

  }

  static void iommu_enable_ga(struct amd_iommu *iommu)
  {
  #ifdef CONFIG_IRQ_REMAP
  	switch (amd_iommu_guest_ir) {
  	case AMD_IOMMU_GUEST_IR_VAPIC:
  		iommu_feature_enable(iommu, CONTROL_GAM_EN);
  		/* Fall through */
  	case AMD_IOMMU_GUEST_IR_LEGACY_GA:
  		iommu_feature_enable(iommu, CONTROL_GA_EN);

  		iommu->irte_ops = &irte_128_ops;

  		break;
  	default:

  		iommu->irte_ops = &irte_32_ops;

  		break;
  	}
  #endif
  }

  /*

   * This function finally enables all IOMMUs found in the system after
   * they have been initialized
   */

  static void early_enable_iommus(void)

  {
  	struct amd_iommu *iommu;

  	for_each_iommu(iommu) {

  		iommu_disable(iommu);

  		iommu_init_flags(iommu);

  		iommu_set_device_table(iommu);
  		iommu_enable_command_buffer(iommu);
  		iommu_enable_event_buffer(iommu);

  		iommu_set_exclusion_range(iommu);

  		iommu_enable_ga(iommu);

  		iommu_enable(iommu);

  		iommu_flush_all_caches(iommu);

  	}

  
  #ifdef CONFIG_IRQ_REMAP
  	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
  		amd_iommu_irq_ops.capability |= (1 << IRQ_POSTING_CAP);
  #endif

  }

  static void enable_iommus_v2(void)
  {
  	struct amd_iommu *iommu;
  
  	for_each_iommu(iommu) {
  		iommu_enable_ppr_log(iommu);
  		iommu_enable_gt(iommu);
  	}
  }
  
  static void enable_iommus(void)
  {
  	early_enable_iommus();
  
  	enable_iommus_v2();
  }

  static void disable_iommus(void)
  {
  	struct amd_iommu *iommu;
  
  	for_each_iommu(iommu)
  		iommu_disable(iommu);

  
  #ifdef CONFIG_IRQ_REMAP
  	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
  		amd_iommu_irq_ops.capability &= ~(1 << IRQ_POSTING_CAP);
  #endif

  }

  /*
   * Suspend/Resume support
   * disable suspend until real resume implemented
   */

  static void amd_iommu_resume(void)

  {

  	struct amd_iommu *iommu;
  
  	for_each_iommu(iommu)
  		iommu_apply_resume_quirks(iommu);

  	/* re-load the hardware */
  	enable_iommus();

  
  	amd_iommu_enable_interrupts();

  }

  static int amd_iommu_suspend(void)

  {

  	/* disable IOMMUs to go out of the way for BIOS */
  	disable_iommus();
  
  	return 0;

  }

  static struct syscore_ops amd_iommu_syscore_ops = {

  	.suspend = amd_iommu_suspend,
  	.resume = amd_iommu_resume,
  };

  static void __init free_on_init_error(void)
  {

  	free_pages((unsigned long)irq_lookup_table,
  		   get_order(rlookup_table_size));

  	kmem_cache_destroy(amd_iommu_irq_cache);
  	amd_iommu_irq_cache = NULL;

  
  	free_pages((unsigned long)amd_iommu_rlookup_table,
  		   get_order(rlookup_table_size));
  
  	free_pages((unsigned long)amd_iommu_alias_table,
  		   get_order(alias_table_size));
  
  	free_pages((unsigned long)amd_iommu_dev_table,
  		   get_order(dev_table_size));
  
  	free_iommu_all();

  #ifdef CONFIG_GART_IOMMU
  	/*
  	 * We failed to initialize the AMD IOMMU - try fallback to GART
  	 * if possible.
  	 */
  	gart_iommu_init();
  
  #endif
  }

  /* SB IOAPIC is always on this device in AMD systems */
  #define IOAPIC_SB_DEVID		((0x00 << 8) | PCI_DEVFN(0x14, 0))

  static bool __init check_ioapic_information(void)
  {

  	const char *fw_bug = FW_BUG;

  	bool ret, has_sb_ioapic;

  	int idx;

  	has_sb_ioapic = false;
  	ret           = false;

  	/*
  	 * If we have map overrides on the kernel command line the
  	 * messages in this function might not describe firmware bugs
  	 * anymore - so be careful
  	 */
  	if (cmdline_maps)
  		fw_bug = "";

  	for (idx = 0; idx < nr_ioapics; idx++) {
  		int devid, id = mpc_ioapic_id(idx);
  
  		devid = get_ioapic_devid(id);
  		if (devid < 0) {

  			pr_err("%sAMD-Vi: IOAPIC[%d] not in IVRS table
  ",
  				fw_bug, id);

  			ret = false;
  		} else if (devid == IOAPIC_SB_DEVID) {
  			has_sb_ioapic = true;
  			ret           = true;

  		}
  	}

  	if (!has_sb_ioapic) {
  		/*
  		 * We expect the SB IOAPIC to be listed in the IVRS
  		 * table. The system timer is connected to the SB IOAPIC
  		 * and if we don't have it in the list the system will
  		 * panic at boot time.  This situation usually happens
  		 * when the BIOS is buggy and provides us the wrong
  		 * device id for the IOAPIC in the system.
  		 */

  		pr_err("%sAMD-Vi: No southbridge IOAPIC found
  ", fw_bug);

  	}
  
  	if (!ret)

  		pr_err("AMD-Vi: Disabling interrupt remapping
  ");

  
  	return ret;

  }

  static void __init free_dma_resources(void)
  {

  	free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
  		   get_order(MAX_DOMAIN_ID/8));
  
  	free_unity_maps();
  }

  /*

   * This is the hardware init function for AMD IOMMU in the system.
   * This function is called either from amd_iommu_init or from the interrupt
   * remapping setup code.

   *
   * This function basically parses the ACPI table for AMD IOMMU (IVRS)

   * four times:

   *

   *	1 pass) Discover the most comprehensive IVHD type to use.
   *
   *	2 pass) Find the highest PCI device id the driver has to handle.

   *		Upon this information the size of the data structures is
   *		determined that needs to be allocated.
   *

   *	3 pass) Initialize the data structures just allocated with the

   *		information in the ACPI table about available AMD IOMMUs
   *		in the system. It also maps the PCI devices in the
   *		system to specific IOMMUs
   *

   *	4 pass) After the basic data structures are allocated and

   *		initialized we update them with information about memory
   *		remapping requirements parsed out of the ACPI table in
   *		this last pass.
   *

   * After everything is set up the IOMMUs are enabled and the necessary
   * hotplug and suspend notifiers are registered.

   */

  static int __init early_amd_iommu_init(void)

  {

  	struct acpi_table_header *ivrs_base;
  	acpi_size ivrs_size;
  	acpi_status status;

  	int i, remap_cache_sz, ret = 0;

  	if (!amd_iommu_detected)

  		return -ENODEV;

  	status = acpi_get_table_with_size("IVRS", 0, &ivrs_base, &ivrs_size);
  	if (status == AE_NOT_FOUND)
  		return -ENODEV;
  	else if (ACPI_FAILURE(status)) {
  		const char *err = acpi_format_exception(status);
  		pr_err("AMD-Vi: IVRS table error: %s
  ", err);
  		return -EINVAL;
  	}

  	/*

  	 * Validate checksum here so we don't need to do it when
  	 * we actually parse the table
  	 */
  	ret = check_ivrs_checksum(ivrs_base);
  	if (ret)
  		return ret;
  
  	amd_iommu_target_ivhd_type = get_highest_supported_ivhd_type(ivrs_base);
  	DUMP_printk("Using IVHD type %#x
  ", amd_iommu_target_ivhd_type);
  
  	/*

  	 * First parse ACPI tables to find the largest Bus/Dev/Func
  	 * we need to handle. Upon this information the shared data
  	 * structures for the IOMMUs in the system will be allocated
  	 */

  	ret = find_last_devid_acpi(ivrs_base);
  	if (ret)

  		goto out;

  	dev_table_size     = tbl_size(DEV_TABLE_ENTRY_SIZE);
  	alias_table_size   = tbl_size(ALIAS_TABLE_ENTRY_SIZE);
  	rlookup_table_size = tbl_size(RLOOKUP_TABLE_ENTRY_SIZE);

  	/* Device table - directly used by all IOMMUs */

  	ret = -ENOMEM;

  	amd_iommu_dev_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,

  				      get_order(dev_table_size));
  	if (amd_iommu_dev_table == NULL)
  		goto out;
  
  	/*
  	 * Alias table - map PCI Bus/Dev/Func to Bus/Dev/Func the
  	 * IOMMU see for that device
  	 */
  	amd_iommu_alias_table = (void *)__get_free_pages(GFP_KERNEL,
  			get_order(alias_table_size));
  	if (amd_iommu_alias_table == NULL)

  		goto out;

  
  	/* IOMMU rlookup table - find the IOMMU for a specific device */

  	amd_iommu_rlookup_table = (void *)__get_free_pages(
  			GFP_KERNEL | __GFP_ZERO,

  			get_order(rlookup_table_size));
  	if (amd_iommu_rlookup_table == NULL)

  		goto out;

  	amd_iommu_pd_alloc_bitmap = (void *)__get_free_pages(
  					    GFP_KERNEL | __GFP_ZERO,

  					    get_order(MAX_DOMAIN_ID/8));
  	if (amd_iommu_pd_alloc_bitmap == NULL)

  		goto out;

  
  	/*

  	 * let all alias entries point to itself

  	 */

  	for (i = 0; i <= amd_iommu_last_bdf; ++i)

  		amd_iommu_alias_table[i] = i;

  	/*
  	 * never allocate domain 0 because its used as the non-allocated and
  	 * error value placeholder
  	 */

  	__set_bit(0, amd_iommu_pd_alloc_bitmap);

  	spin_lock_init(&amd_iommu_pd_lock);

  	/*
  	 * now the data structures are allocated and basically initialized
  	 * start the real acpi table scan
  	 */

  	ret = init_iommu_all(ivrs_base);
  	if (ret)

  		goto out;

  	if (amd_iommu_irq_remap)
  		amd_iommu_irq_remap = check_ioapic_information();

  	if (amd_iommu_irq_remap) {
  		/*
  		 * Interrupt remapping enabled, create kmem_cache for the
  		 * remapping tables.
  		 */

  		ret = -ENOMEM;

  		if (!AMD_IOMMU_GUEST_IR_GA(amd_iommu_guest_ir))
  			remap_cache_sz = MAX_IRQS_PER_TABLE * sizeof(u32);
  		else
  			remap_cache_sz = MAX_IRQS_PER_TABLE * (sizeof(u64) * 2);

  		amd_iommu_irq_cache = kmem_cache_create("irq_remap_cache",

  							remap_cache_sz,
  							IRQ_TABLE_ALIGNMENT,
  							0, NULL);