linux/drivers/iommu/amd/iommu.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2007-2010 Advanced Micro Devices, Inc.
 * Author: Joerg Roedel <jroedel@suse.de>
 *         Leo Duran <leo.duran@amd.com>
 */

#define pr_fmt(fmt)     "AMD-Vi: " fmt
#define dev_fmt(fmt)    pr_fmt(fmt)

#include <linux/ratelimit.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/amba/bus.h>
#include <linux/platform_device.h>
#include <linux/pci-ats.h>
#include <linux/bitmap.h>
#include <linux/slab.h>
#include <linux/debugfs.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/dma-direct.h>
#include <linux/dma-iommu.h>
#include <linux/iommu-helper.h>
#include <linux/delay.h>
#include <linux/amd-iommu.h>
#include <linux/notifier.h>
#include <linux/export.h>
#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/dma-contiguous.h>
#include <linux/irqdomain.h>
#include <linux/percpu.h>
#include <linux/iova.h>
#include <asm/irq_remapping.h>
#include <asm/io_apic.h>
#include <asm/apic.h>
#include <asm/hw_irq.h>
#include <asm/msidef.h>
#include <asm/proto.h>
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/dma.h>

#include "amd_iommu.h"
#include "../irq_remapping.h"

#define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))

#define LOOP_TIMEOUT	100000

/* IO virtual address start page frame number */
#define IOVA_START_PFN		(1)
#define IOVA_PFN(addr)		((addr) >> PAGE_SHIFT)

/* Reserved IOVA ranges */
#define MSI_RANGE_START		(0xfee00000)
#define MSI_RANGE_END		(0xfeefffff)
#define HT_RANGE_START		(0xfd00000000ULL)
#define HT_RANGE_END		(0xffffffffffULL)

/*
 * This bitmap is used to advertise the page sizes our hardware support
 * to the IOMMU core, which will then use this information to split
 * physically contiguous memory regions it is mapping into page sizes
 * that we support.
 *
 * 512GB Pages are not supported due to a hardware bug
 */
#define AMD_IOMMU_PGSIZES	((~0xFFFUL) & ~(2ULL << 38))

#define DEFAULT_PGTABLE_LEVEL	PAGE_MODE_3_LEVEL

static DEFINE_SPINLOCK(pd_bitmap_lock);

/* List of all available dev_data structures */
static LLIST_HEAD(dev_data_list);

LIST_HEAD(ioapic_map);
LIST_HEAD(hpet_map);
LIST_HEAD(acpihid_map);

/*
 * Domain for untranslated devices - only allocated
 * if iommu=pt passed on kernel cmd line.
 */
const struct iommu_ops amd_iommu_ops;

static ATOMIC_NOTIFIER_HEAD(ppr_notifier);
int amd_iommu_max_glx_val = -1;

/*
 * general struct to manage commands send to an IOMMU
 */
struct iommu_cmd {
	u32 data[4];
};

struct kmem_cache *amd_iommu_irq_cache;

static void update_domain(struct protection_domain *domain);
static void detach_device(struct device *dev);
static void update_and_flush_device_table(struct protection_domain *domain,
					  struct domain_pgtable *pgtable);

/****************************************************************************
 *
 * Helper functions
 *
 ****************************************************************************/

static inline u16 get_pci_device_id(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	return pci_dev_id(pdev);
}

static inline int get_acpihid_device_id(struct device *dev,
					struct acpihid_map_entry **entry)
{
	struct acpi_device *adev = ACPI_COMPANION(dev);
	struct acpihid_map_entry *p;

	if (!adev)
		return -ENODEV;

	list_for_each_entry(p, &acpihid_map, list) {
		if (acpi_dev_hid_uid_match(adev, p->hid,
					   p->uid[0] ? p->uid : NULL)) {
			if (entry)
				*entry = p;
			return p->devid;
		}
	}
	return -EINVAL;
}

static inline int get_device_id(struct device *dev)
{
	int devid;

	if (dev_is_pci(dev))
		devid = get_pci_device_id(dev);
	else
		devid = get_acpihid_device_id(dev, NULL);

	return devid;
}

static struct protection_domain *to_pdomain(struct iommu_domain *dom)
{
	return container_of(dom, struct protection_domain, domain);
}

static void amd_iommu_domain_get_pgtable(struct protection_domain *domain,
					 struct domain_pgtable *pgtable)
{
	u64 pt_root = atomic64_read(&domain->pt_root);

	pgtable->root = (u64 *)(pt_root & PAGE_MASK);
	pgtable->mode = pt_root & 7; /* lowest 3 bits encode pgtable mode */
}

static u64 amd_iommu_domain_encode_pgtable(u64 *root, int mode)
{
	u64 pt_root;

	/* lowest 3 bits encode pgtable mode */
	pt_root = mode & 7;
	pt_root |= (u64)root;

	return pt_root;
}

static struct iommu_dev_data *alloc_dev_data(u16 devid)
{
	struct iommu_dev_data *dev_data;

	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
	if (!dev_data)
		return NULL;

	spin_lock_init(&dev_data->lock);
	dev_data->devid = devid;
	ratelimit_default_init(&dev_data->rs);

	llist_add(&dev_data->dev_data_list, &dev_data_list);
	return dev_data;
}

static struct iommu_dev_data *search_dev_data(u16 devid)
{
	struct iommu_dev_data *dev_data;
	struct llist_node *node;

	if (llist_empty(&dev_data_list))
		return NULL;

	node = dev_data_list.first;
	llist_for_each_entry(dev_data, node, dev_data_list) {
		if (dev_data->devid == devid)
			return dev_data;
	}

	return NULL;
}

static int clone_alias(struct pci_dev *pdev, u16 alias, void *data)
{
	u16 devid = pci_dev_id(pdev);

	if (devid == alias)
		return 0;

	amd_iommu_rlookup_table[alias] =
		amd_iommu_rlookup_table[devid];
	memcpy(amd_iommu_dev_table[alias].data,
	       amd_iommu_dev_table[devid].data,
	       sizeof(amd_iommu_dev_table[alias].data));

	return 0;
}

static void clone_aliases(struct pci_dev *pdev)
{
	if (!pdev)
		return;

	/*
	 * The IVRS alias stored in the alias table may not be
	 * part of the PCI DMA aliases if it's bus differs
	 * from the original device.
	 */
	clone_alias(pdev, amd_iommu_alias_table[pci_dev_id(pdev)], NULL);

	pci_for_each_dma_alias(pdev, clone_alias, NULL);
}

static struct pci_dev *setup_aliases(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	u16 ivrs_alias;

	/* For ACPI HID devices, there are no aliases */
	if (!dev_is_pci(dev))
		return NULL;

	/*
	 * Add the IVRS alias to the pci aliases if it is on the same
	 * bus. The IVRS table may know about a quirk that we don't.
	 */
	ivrs_alias = amd_iommu_alias_table[pci_dev_id(pdev)];
	if (ivrs_alias != pci_dev_id(pdev) &&
	    PCI_BUS_NUM(ivrs_alias) == pdev->bus->number)
		pci_add_dma_alias(pdev, ivrs_alias & 0xff, 1);

	clone_aliases(pdev);

	return pdev;
}

static struct iommu_dev_data *find_dev_data(u16 devid)
{
	struct iommu_dev_data *dev_data;
	struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];

	dev_data = search_dev_data(devid);

	if (dev_data == NULL) {
		dev_data = alloc_dev_data(devid);
		if (!dev_data)
			return NULL;

		if (translation_pre_enabled(iommu))
			dev_data->defer_attach = true;
	}

	return dev_data;
}

/*
* Find or create an IOMMU group for a acpihid device.
*/
static struct iommu_group *acpihid_device_group(struct device *dev)
{
	struct acpihid_map_entry *p, *entry = NULL;
	int devid;

	devid = get_acpihid_device_id(dev, &entry);
	if (devid < 0)
		return ERR_PTR(devid);

	list_for_each_entry(p, &acpihid_map, list) {
		if ((devid == p->devid) && p->group)
			entry->group = p->group;
	}

	if (!entry->group)
		entry->group = generic_device_group(dev);
	else
		iommu_group_ref_get(entry->group);

	return entry->group;
}

static bool pci_iommuv2_capable(struct pci_dev *pdev)
{
	static const int caps[] = {
		PCI_EXT_CAP_ID_PRI,
		PCI_EXT_CAP_ID_PASID,
	};
	int i, pos;

	if (!pci_ats_supported(pdev))
		return false;

	for (i = 0; i < 2; ++i) {
		pos = pci_find_ext_capability(pdev, caps[i]);
		if (pos == 0)
			return false;
	}

	return true;
}

static bool pdev_pri_erratum(struct pci_dev *pdev, u32 erratum)
{
	struct iommu_dev_data *dev_data;

	dev_data = dev_iommu_priv_get(&pdev->dev);

	return dev_data->errata & (1 << erratum) ? true : false;
}

/*
 * This function checks if the driver got a valid device from the caller to
 * avoid dereferencing invalid pointers.
 */
static bool check_device(struct device *dev)
{
	int devid;

	if (!dev)
		return false;

	devid = get_device_id(dev);
	if (devid < 0)
		return false;

	/* Out of our scope? */
	if (devid > amd_iommu_last_bdf)
		return false;

	if (amd_iommu_rlookup_table[devid] == NULL)
		return false;

	return true;
}

static int iommu_init_device(struct device *dev)
{
	struct iommu_dev_data *dev_data;
	int devid;

	if (dev_iommu_priv_get(dev))
		return 0;

	devid = get_device_id(dev);
	if (devid < 0)
		return devid;

	dev_data = find_dev_data(devid);
	if (!dev_data)
		return -ENOMEM;

	dev_data->pdev = setup_aliases(dev);

	/*
	 * By default we use passthrough mode for IOMMUv2 capable device.
	 * But if amd_iommu=force_isolation is set (e.g. to debug DMA to
	 * invalid address), we ignore the capability for the device so
	 * it'll be forced to go into translation mode.
	 */
	if ((iommu_default_passthrough() || !amd_iommu_force_isolation) &&
	    dev_is_pci(dev) && pci_iommuv2_capable(to_pci_dev(dev))) {
		struct amd_iommu *iommu;

		iommu = amd_iommu_rlookup_table[dev_data->devid];
		dev_data->iommu_v2 = iommu->is_iommu_v2;
	}

	dev_iommu_priv_set(dev, dev_data);

	return 0;
}

static void iommu_ignore_device(struct device *dev)
{
	int devid;

	devid = get_device_id(dev);
	if (devid < 0)
		return;

	amd_iommu_rlookup_table[devid] = NULL;
	memset(&amd_iommu_dev_table[devid], 0, sizeof(struct dev_table_entry));

	setup_aliases(dev);
}

static void amd_iommu_uninit_device(struct device *dev)
{
	struct iommu_dev_data *dev_data;

	dev_data = dev_iommu_priv_get(dev);
	if (!dev_data)
		return;

	if (dev_data->domain)
		detach_device(dev);

	dev_iommu_priv_set(dev, NULL);

	/*
	 * We keep dev_data around for unplugged devices and reuse it when the
	 * device is re-plugged - not doing so would introduce a ton of races.
	 */
}

/*
 * Helper function to get the first pte of a large mapping
 */
static u64 *first_pte_l7(u64 *pte, unsigned long *page_size,
			 unsigned long *count)
{
	unsigned long pte_mask, pg_size, cnt;
	u64 *fpte;

	pg_size  = PTE_PAGE_SIZE(*pte);
	cnt      = PAGE_SIZE_PTE_COUNT(pg_size);
	pte_mask = ~((cnt << 3) - 1);
	fpte     = (u64 *)(((unsigned long)pte) & pte_mask);

	if (page_size)
		*page_size = pg_size;

	if (count)
		*count = cnt;

	return fpte;
}

/****************************************************************************
 *
 * Interrupt handling functions
 *
 ****************************************************************************/

static void dump_dte_entry(u16 devid)
{
	int i;

	for (i = 0; i < 4; ++i)
		pr_err("DTE[%d]: %016llx\n", i,
			amd_iommu_dev_table[devid].data[i]);
}

static void dump_command(unsigned long phys_addr)
{
	struct iommu_cmd *cmd = iommu_phys_to_virt(phys_addr);
	int i;

	for (i = 0; i < 4; ++i)
		pr_err("CMD[%d]: %08x\n", i, cmd->data[i]);
}

static void amd_iommu_report_page_fault(u16 devid, u16 domain_id,
					u64 address, int flags)
{
	struct iommu_dev_data *dev_data = NULL;
	struct pci_dev *pdev;

	pdev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(devid),
					   devid & 0xff);
	if (pdev)
		dev_data = dev_iommu_priv_get(&pdev->dev);

	if (dev_data && __ratelimit(&dev_data->rs)) {
		pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n",
			domain_id, address, flags);
	} else if (printk_ratelimit()) {
		pr_err("Event logged [IO_PAGE_FAULT device=%02x:%02x.%x domain=0x%04x address=0x%llx flags=0x%04x]\n",
			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
			domain_id, address, flags);
	}

	if (pdev)
		pci_dev_put(pdev);
}

static void iommu_print_event(struct amd_iommu *iommu, void *__evt)
{
	struct device *dev = iommu->iommu.dev;
	int type, devid, pasid, flags, tag;
	volatile u32 *event = __evt;
	int count = 0;
	u64 address;

retry:
	type    = (event[1] >> EVENT_TYPE_SHIFT)  & EVENT_TYPE_MASK;
	devid   = (event[0] >> EVENT_DEVID_SHIFT) & EVENT_DEVID_MASK;
	pasid   = (event[0] & EVENT_DOMID_MASK_HI) |
		  (event[1] & EVENT_DOMID_MASK_LO);
	flags   = (event[1] >> EVENT_FLAGS_SHIFT) & EVENT_FLAGS_MASK;
	address = (u64)(((u64)event[3]) << 32) | event[2];

	if (type == 0) {
		/* Did we hit the erratum? */
		if (++count == LOOP_TIMEOUT) {
			pr_err("No event written to event log\n");
			return;
		}
		udelay(1);
		goto retry;
	}

	if (type == EVENT_TYPE_IO_FAULT) {
		amd_iommu_report_page_fault(devid, pasid, address, flags);
		return;
	}

	switch (type) {
	case EVENT_TYPE_ILL_DEV:
		dev_err(dev, "Event logged [ILLEGAL_DEV_TABLE_ENTRY device=%02x:%02x.%x pasid=0x%05x address=0x%llx flags=0x%04x]\n",
			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
			pasid, address, flags);
		dump_dte_entry(devid);
		break;
	case EVENT_TYPE_DEV_TAB_ERR:
		dev_err(dev, "Event logged [DEV_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
			"address=0x%llx flags=0x%04x]\n",
			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
			address, flags);
		break;
	case EVENT_TYPE_PAGE_TAB_ERR:
		dev_err(dev, "Event logged [PAGE_TAB_HARDWARE_ERROR device=%02x:%02x.%x pasid=0x%04x address=0x%llx flags=0x%04x]\n",
			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
			pasid, address, flags);
		break;
	case EVENT_TYPE_ILL_CMD:
		dev_err(dev, "Event logged [ILLEGAL_COMMAND_ERROR address=0x%llx]\n", address);
		dump_command(address);
		break;
	case EVENT_TYPE_CMD_HARD_ERR:
		dev_err(dev, "Event logged [COMMAND_HARDWARE_ERROR address=0x%llx flags=0x%04x]\n",
			address, flags);
		break;
	case EVENT_TYPE_IOTLB_INV_TO:
		dev_err(dev, "Event logged [IOTLB_INV_TIMEOUT device=%02x:%02x.%x address=0x%llx]\n",
			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
			address);
		break;
	case EVENT_TYPE_INV_DEV_REQ:
		dev_err(dev, "Event logged [INVALID_DEVICE_REQUEST device=%02x:%02x.%x pasid=0x%05x address=0x%llx flags=0x%04x]\n",
			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
			pasid, address, flags);
		break;
	case EVENT_TYPE_INV_PPR_REQ:
		pasid = PPR_PASID(*((u64 *)__evt));
		tag = event[1] & 0x03FF;
		dev_err(dev, "Event logged [INVALID_PPR_REQUEST device=%02x:%02x.%x pasid=0x%05x address=0x%llx flags=0x%04x tag=0x%03x]\n",
			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
			pasid, address, flags, tag);
		break;
	default:
		dev_err(dev, "Event logged [UNKNOWN event[0]=0x%08x event[1]=0x%08x event[2]=0x%08x event[3]=0x%08x\n",
			event[0], event[1], event[2], event[3]);
	}

	memset(__evt, 0, 4 * sizeof(u32));
}

static void iommu_poll_events(struct amd_iommu *iommu)
{
	u32 head, tail;

	head = readl(iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
	tail = readl(iommu->mmio_base + MMIO_EVT_TAIL_OFFSET);

	while (head != tail) {
		iommu_print_event(iommu, iommu->evt_buf + head);
		head = (head + EVENT_ENTRY_SIZE) % EVT_BUFFER_SIZE;
	}

	writel(head, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
}

static void iommu_handle_ppr_entry(struct amd_iommu *iommu, u64 *raw)
{
	struct amd_iommu_fault fault;

	if (PPR_REQ_TYPE(raw[0]) != PPR_REQ_FAULT) {
		pr_err_ratelimited("Unknown PPR request received\n");
		return;
	}

	fault.address   = raw[1];
	fault.pasid     = PPR_PASID(raw[0]);
	fault.device_id = PPR_DEVID(raw[0]);
	fault.tag       = PPR_TAG(raw[0]);
	fault.flags     = PPR_FLAGS(raw[0]);

	atomic_notifier_call_chain(&ppr_notifier, 0, &fault);
}

static void iommu_poll_ppr_log(struct amd_iommu *iommu)
{
	u32 head, tail;

	if (iommu->ppr_log == NULL)
		return;

	head = readl(iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);
	tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET);

	while (head != tail) {
		volatile u64 *raw;
		u64 entry[2];
		int i;

		raw = (u64 *)(iommu->ppr_log + head);

		/*
		 * Hardware bug: Interrupt may arrive before the entry is
		 * written to memory. If this happens we need to wait for the
		 * entry to arrive.
		 */
		for (i = 0; i < LOOP_TIMEOUT; ++i) {
			if (PPR_REQ_TYPE(raw[0]) != 0)
				break;
			udelay(1);
		}

		/* Avoid memcpy function-call overhead */
		entry[0] = raw[0];
		entry[1] = raw[1];

		/*
		 * To detect the hardware bug we need to clear the entry
		 * back to zero.
		 */
		raw[0] = raw[1] = 0UL;

		/* Update head pointer of hardware ring-buffer */
		head = (head + PPR_ENTRY_SIZE) % PPR_LOG_SIZE;
		writel(head, iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);

		/* Handle PPR entry */
		iommu_handle_ppr_entry(iommu, entry);

		/* Refresh ring-buffer information */
		head = readl(iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);
		tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET);
	}
}

#ifdef CONFIG_IRQ_REMAP
static int (*iommu_ga_log_notifier)(u32);

int amd_iommu_register_ga_log_notifier(int (*notifier)(u32))
{
	iommu_ga_log_notifier = notifier;

	return 0;
}
EXPORT_SYMBOL(amd_iommu_register_ga_log_notifier);

static void iommu_poll_ga_log(struct amd_iommu *iommu)
{
	u32 head, tail, cnt = 0;

	if (iommu->ga_log == NULL)
		return;

	head = readl(iommu->mmio_base + MMIO_GA_HEAD_OFFSET);
	tail = readl(iommu->mmio_base + MMIO_GA_TAIL_OFFSET);

	while (head != tail) {
		volatile u64 *raw;
		u64 log_entry;

		raw = (u64 *)(iommu->ga_log + head);
		cnt++;

		/* Avoid memcpy function-call overhead */
		log_entry = *raw;

		/* Update head pointer of hardware ring-buffer */
		head = (head + GA_ENTRY_SIZE) % GA_LOG_SIZE;
		writel(head, iommu->mmio_base + MMIO_GA_HEAD_OFFSET);

		/* Handle GA entry */
		switch (GA_REQ_TYPE(log_entry)) {
		case GA_GUEST_NR:
			if (!iommu_ga_log_notifier)
				break;

			pr_debug("%s: devid=%#x, ga_tag=%#x\n",
				 __func__, GA_DEVID(log_entry),
				 GA_TAG(log_entry));

			if (iommu_ga_log_notifier(GA_TAG(log_entry)) != 0)
				pr_err("GA log notifier failed.\n");
			break;
		default:
			break;
		}
	}
}
#endif /* CONFIG_IRQ_REMAP */

#define AMD_IOMMU_INT_MASK	\
	(MMIO_STATUS_EVT_INT_MASK | \
	 MMIO_STATUS_PPR_INT_MASK | \
	 MMIO_STATUS_GALOG_INT_MASK)

irqreturn_t amd_iommu_int_thread(int irq, void *data)
{
	struct amd_iommu *iommu = (struct amd_iommu *) data;
	u32 status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);

	while (status & AMD_IOMMU_INT_MASK) {
		/* Enable EVT and PPR and GA interrupts again */
		writel(AMD_IOMMU_INT_MASK,
			iommu->mmio_base + MMIO_STATUS_OFFSET);

		if (status & MMIO_STATUS_EVT_INT_MASK) {
			pr_devel("Processing IOMMU Event Log\n");
			iommu_poll_events(iommu);
		}

		if (status & MMIO_STATUS_PPR_INT_MASK) {
			pr_devel("Processing IOMMU PPR Log\n");
			iommu_poll_ppr_log(iommu);
		}

#ifdef CONFIG_IRQ_REMAP
		if (status & MMIO_STATUS_GALOG_INT_MASK) {
			pr_devel("Processing IOMMU GA Log\n");
			iommu_poll_ga_log(iommu);
		}
#endif

		/*
		 * Hardware bug: ERBT1312
		 * When re-enabling interrupt (by writing 1
		 * to clear the bit), the hardware might also try to set
		 * the interrupt bit in the event status register.
		 * In this scenario, the bit will be set, and disable
		 * subsequent interrupts.
		 *
		 * Workaround: The IOMMU driver should read back the
		 * status register and check if the interrupt bits are cleared.
		 * If not, driver will need to go through the interrupt handler
		 * again and re-clear the bits
		 */
		status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
	}
	return IRQ_HANDLED;
}

irqreturn_t amd_iommu_int_handler(int irq, void *data)
{
	return IRQ_WAKE_THREAD;
}

/****************************************************************************
 *
 * IOMMU command queuing functions
 *
 ****************************************************************************/

static int wait_on_sem(volatile u64 *sem)
{
	int i = 0;

	while (*sem == 0 && i < LOOP_TIMEOUT) {
		udelay(1);
		i += 1;
	}

	if (i == LOOP_TIMEOUT) {
		pr_alert("Completion-Wait loop timed out\n");
		return -EIO;
	}

	return 0;
}

static void copy_cmd_to_buffer(struct amd_iommu *iommu,
			       struct iommu_cmd *cmd)
{
	u8 *target;
	u32 tail;

	/* Copy command to buffer */
	tail = iommu->cmd_buf_tail;
	target = iommu->cmd_buf + tail;
	memcpy(target, cmd, sizeof(*cmd));

	tail = (tail + sizeof(*cmd)) % CMD_BUFFER_SIZE;
	iommu->cmd_buf_tail = tail;

	/* Tell the IOMMU about it */
	writel(tail, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
}

static void build_completion_wait(struct iommu_cmd *cmd, u64 address)
{
	u64 paddr = iommu_virt_to_phys((void *)address);

	WARN_ON(address & 0x7ULL);

	memset(cmd, 0, sizeof(*cmd));
	cmd->data[0] = lower_32_bits(paddr) | CMD_COMPL_WAIT_STORE_MASK;
	cmd->data[1] = upper_32_bits(paddr);
	cmd->data[2] = 1;
	CMD_SET_TYPE(cmd, CMD_COMPL_WAIT);
}

static void build_inv_dte(struct iommu_cmd *cmd, u16 devid)
{
	memset(cmd, 0, sizeof(*cmd));
	cmd->data[0] = devid;
	CMD_SET_TYPE(cmd, CMD_INV_DEV_ENTRY);
}

static void build_inv_iommu_pages(struct iommu_cmd *cmd, u64 address,
				  size_t size, u16 domid, int pde)
{
	u64 pages;
	bool s;

	pages = iommu_num_pages(address, size, PAGE_SIZE);
	s     = false;

	if (pages > 1) {
		/*
		 * If we have to flush more than one page, flush all
		 * TLB entries for this domain
		 */
		address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS;
		s = true;
	}

	address &= PAGE_MASK;

	memset(cmd, 0, sizeof(*cmd));
	cmd->data[1] |= domid;
	cmd->data[2]  = lower_32_bits(address);
	cmd->data[3]  = upper_32_bits(address);
	CMD_SET_TYPE(cmd, CMD_INV_IOMMU_PAGES);
	if (s) /* size bit - we flush more than one 4kb page */
		cmd->data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
	if (pde) /* PDE bit - we want to flush everything, not only the PTEs */
		cmd->data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
}

static void build_inv_iotlb_pages(struct iommu_cmd *cmd, u16 devid, int qdep,
				  u64 address, size_t size)
{
	u64 pages;
	bool s;

	pages = iommu_num_pages(address, size, PAGE_SIZE);
	s     = false;

	if (pages > 1) {
		/*
		 * If we have to flush more than one page, flush all
		 * TLB entries for this domain
		 */
		address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS;
		s = true;
	}

	address &= PAGE_MASK;

	memset(cmd, 0, sizeof(*cmd));
	cmd->data[0]  = devid;
	cmd->data[0] |= (qdep & 0xff) << 24;
	cmd->data[1]  = devid;
	cmd->data[2]  = lower_32_bits(address);
	cmd->data[3]  = upper_32_bits(address);
	CMD_SET_TYPE(cmd, CMD_INV_IOTLB_PAGES);
	if (s)
		cmd->data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
}

static void build_inv_iommu_pasid(struct iommu_cmd *cmd, u16 domid, int pasid,
				  u64 address, bool size)
{
	memset(cmd, 0, sizeof(*cmd));

	address &= ~(0xfffULL);

	cmd->data[0]  = pasid;
	cmd->data[1]  = domid;
	cmd->data[2]  = lower_32_bits(address);
	cmd->data[3]  = upper_32_bits(address);
	cmd->data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
	cmd->data[2] |= CMD_INV_IOMMU_PAGES_GN_MASK;
	if (size)
		cmd->data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
	CMD_SET_TYPE(cmd, CMD_INV_IOMMU_PAGES);
}

static void build_inv_iotlb_pasid(struct iommu_cmd *cmd, u16 devid, int pasid,
				  int qdep, u64 address, bool size)
{
	memset(cmd, 0, sizeof(*cmd));

	address &= ~(0xfffULL);

	cmd->data[0]  = devid;
	cmd->data[0] |= ((pasid >> 8) & 0xff) << 16;
	cmd->data[0] |= (qdep  & 0xff) << 24;
	cmd->data[1]  = devid;
	cmd->data[1] |= (pasid & 0xff) << 16;
	cmd->data[2]  = lower_32_bits(address);
	cmd->data[2] |= CMD_INV_IOMMU_PAGES_GN_MASK;
	cmd->data[3]  = upper_32_bits(address);
	if (size)
		cmd->data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
	CMD_SET_TYPE(cmd, CMD_INV_IOTLB_PAGES);
}

static void build_complete_ppr(struct iommu_cmd *cmd, u16 devid, int pasid,
			       int status, int tag, bool gn)
{
	memset(cmd, 0, sizeof(*cmd));

	cmd->data[0]  = devid;
	if (gn) {
		cmd->data[1]  = pasid;
		cmd->data[2]  = CMD_INV_IOMMU_PAGES_GN_MASK;
	}
	cmd->data[3]  = tag & 0x1ff;
	cmd->data[3] |= (status & PPR_STATUS_MASK) << PPR_STATUS_SHIFT;

	CMD_SET_TYPE(cmd, CMD_COMPLETE_PPR);
}

static void build_inv_all(struct iommu_cmd *cmd)
{
	memset(cmd, 0, sizeof(*cmd));
	CMD_SET_TYPE(cmd, CMD_INV_ALL);
}

static void build_inv_irt(struct iommu_cmd *cmd, u16 devid)
{
	memset(cmd, 0, sizeof(*cmd));
	cmd->data[0] = devid;
	CMD_SET_TYPE(cmd, CMD_INV_IRT);
}

/*
 * Writes the command to the IOMMUs command buffer and informs the
 * hardware about the new command.
 */
static int __iommu_queue_command_sync(struct amd_iommu *iommu,
				      struct iommu_cmd *cmd,
				      bool sync)
{
	unsigned int count = 0;
	u32 left, next_tail;

	next_tail = (iommu->cmd_buf_tail + sizeof(*cmd)) % CMD_BUFFER_SIZE;
again:
	left      = (iommu->cmd_buf_head - next_tail) % CMD_BUFFER_SIZE;

	if (left <= 0x20) {
		/* Skip udelay() the first time around */
		if (count++) {
			if (count == LOOP_TIMEOUT) {
				pr_err("Command buffer timeout\n");
				return -EIO;
			}

			udelay(1);
		}

		/* Update head and recheck remaining space */
		iommu->cmd_buf_head = readl(iommu->mmio_base +
					    MMIO_CMD_HEAD_OFFSET);

		goto again;
	}

	copy_cmd_to_buffer(iommu, cmd);

	/* Do we need to make sure all commands are processed? */
	iommu->need_sync = sync;

	return 0;
}

static int iommu_queue_command_sync(struct amd_iommu *iommu,
				    struct iommu_cmd *cmd,
				    bool sync)
{
	unsigned long flags;
	int ret;

	raw_spin_lock_irqsave(&iommu->lock, flags);
	ret = __iommu_queue_command_sync(iommu, cmd, sync);
	raw_spin_unlock_irqrestore(&iommu->lock, flags);

	return ret;
}

static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
{
	return iommu_queue_command_sync(iommu, cmd, true);
}

/*
 * This function queues a completion wait command into the command
 * buffer of an IOMMU
 */
static int iommu_completion_wait(struct amd_iommu *iommu)
{
	struct iommu_cmd cmd;
	unsigned long flags;
	int ret;

	if (!iommu->need_sync)
		return 0;


	build_completion_wait(&cmd, (u64)&iommu->cmd_sem);

	raw_spin_lock_irqsave(&iommu->lock, flags);

	iommu->cmd_sem = 0;

	ret = __iommu_queue_command_sync(iommu, &cmd, false);
	if (ret)
		goto out_unlock;

	ret = wait_on_sem(&iommu->cmd_sem);

out_unlock:
	raw_spin_unlock_irqrestore(&iommu->lock, flags);

	return ret;
}

static int iommu_flush_dte(struct amd_iommu *iommu, u16 devid)
{
	struct iommu_cmd cmd;

	build_inv_dte(&cmd, devid);

	return iommu_queue_command(iommu, &cmd);
}

static void amd_iommu_flush_dte_all(struct amd_iommu *iommu)
{
	u32 devid;

	for (devid = 0; devid <= 0xffff; ++devid)
		iommu_flush_dte(iommu, devid);

	iommu_completion_wait(iommu);
}

/*
 * This function uses heavy locking and may disable irqs for some time. But
 * this is no issue because it is only called during resume.
 */
static void amd_iommu_flush_tlb_all(struct amd_iommu *iommu)
{
	u32 dom_id;

	for (dom_id = 0; dom_id <= 0xffff; ++dom_id) {
		struct iommu_cmd cmd;
		build_inv_iommu_pages(&cmd, 0, CMD_INV_IOMMU_ALL_PAGES_ADDRESS,
				      dom_id, 1);
		iommu_queue_command(iommu, &cmd);
	}

	iommu_completion_wait(iommu);
}

static void amd_iommu_flush_tlb_domid(struct amd_iommu *iommu, u32 dom_id)
{
	struct iommu_cmd cmd;

	build_inv_iommu_pages(&cmd, 0, CMD_INV_IOMMU_ALL_PAGES_ADDRESS,
			      dom_id, 1);
	iommu_queue_command(iommu, &cmd);

	iommu_completion_wait(iommu);
}

static void amd_iommu_flush_all(struct amd_iommu *iommu)
{
	struct iommu_cmd cmd;

	build_inv_all(&cmd);

	iommu_queue_command(iommu, &cmd);
	iommu_completion_wait(iommu);
}

static void iommu_flush_irt(struct amd_iommu *iommu, u16 devid)
{
	struct iommu_cmd cmd;

	build_inv_irt(&cmd, devid);

	iommu_queue_command(iommu, &cmd);
}

static void amd_iommu_flush_irt_all(struct amd_iommu *iommu)
{
	u32 devid;

	for (devid = 0; devid <= MAX_DEV_TABLE_ENTRIES; devid++)
		iommu_flush_irt(iommu, devid);

	iommu_completion_wait(iommu);
}

void iommu_flush_all_caches(struct amd_iommu *iommu)
{
	if (iommu_feature(iommu, FEATURE_IA)) {
		amd_iommu_flush_all(iommu);
	} else {
		amd_iommu_flush_dte_all(iommu);
		amd_iommu_flush_irt_all(iommu);
		amd_iommu_flush_tlb_all(iommu);
	}
}

/*
 * Command send function for flushing on-device TLB
 */
static int device_flush_iotlb(struct iommu_dev_data *dev_data,
			      u64 address, size_t size)
{
	struct amd_iommu *iommu;
	struct iommu_cmd cmd;
	int qdep;

	qdep     = dev_data->ats.qdep;
	iommu    = amd_iommu_rlookup_table[dev_data->devid];

	build_inv_iotlb_pages(&cmd, dev_data->devid, qdep, address, size);

	return iommu_queue_command(iommu, &cmd);
}

static int device_flush_dte_alias(struct pci_dev *pdev, u16 alias, void *data)
{
	struct amd_iommu *iommu = data;

	return iommu_flush_dte(iommu, alias);
}

/*
 * Command send function for invalidating a device table entry
 */
static int device_flush_dte(struct iommu_dev_data *dev_data)
{
	struct amd_iommu *iommu;
	u16 alias;
	int ret;

	iommu = amd_iommu_rlookup_table[dev_data->devid];

	if (dev_data->pdev)
		ret = pci_for_each_dma_alias(dev_data->pdev,
					     device_flush_dte_alias, iommu);
	else
		ret = iommu_flush_dte(iommu, dev_data->devid);
	if (ret)
		return ret;

	alias = amd_iommu_alias_table[dev_data->devid];
	if (alias != dev_data->devid) {
		ret = iommu_flush_dte(iommu, alias);
		if (ret)
			return ret;
	}

	if (dev_data->ats.enabled)
		ret = device_flush_iotlb(dev_data, 0, ~0UL);

	return ret;
}

/*
 * TLB invalidation function which is called from the mapping functions.
 * It invalidates a single PTE if the range to flush is within a single
 * page. Otherwise it flushes the whole TLB of the IOMMU.
 */
static void __domain_flush_pages(struct protection_domain *domain,
				 u64 address, size_t size, int pde)
{
	struct iommu_dev_data *dev_data;
	struct iommu_cmd cmd;
	int ret = 0, i;

	build_inv_iommu_pages(&cmd, address, size, domain->id, pde);

	for (i = 0; i < amd_iommu_get_num_iommus(); ++i) {
		if (!domain->dev_iommu[i])
			continue;

		/*
		 * Devices of this domain are behind this IOMMU
		 * We need a TLB flush
		 */
		ret |= iommu_queue_command(amd_iommus[i], &cmd);
	}

	list_for_each_entry(dev_data, &domain->dev_list, list) {

		if (!dev_data->ats.enabled)
			continue;

		ret |= device_flush_iotlb(dev_data, address, size);
	}

	WARN_ON(ret);
}

static void domain_flush_pages(struct protection_domain *domain,
			       u64 address, size_t size)
{
	__domain_flush_pages(domain, address, size, 0);
}

/* Flush the whole IO/TLB for a given protection domain - including PDE */
static void domain_flush_tlb_pde(struct protection_domain *domain)
{
	__domain_flush_pages(domain, 0, CMD_INV_IOMMU_ALL_PAGES_ADDRESS, 1);
}

static void domain_flush_complete(struct protection_domain *domain)
{
	int i;

	for (i = 0; i < amd_iommu_get_num_iommus(); ++i) {
		if (domain && !domain->dev_iommu[i])
			continue;

		/*
		 * Devices of this domain are behind this IOMMU
		 * We need to wait for completion of all commands.
		 */
		iommu_completion_wait(amd_iommus[i]);
	}
}

/* Flush the not present cache if it exists */
static void domain_flush_np_cache(struct protection_domain *domain,
		dma_addr_t iova, size_t size)
{
	if (unlikely(amd_iommu_np_cache)) {
		unsigned long flags;

		spin_lock_irqsave(&domain->lock, flags);
		domain_flush_pages(domain, iova, size);
		domain_flush_complete(domain);
		spin_unlock_irqrestore(&domain->lock, flags);
	}
}


/*
 * This function flushes the DTEs for all devices in domain
 */
static void domain_flush_devices(struct protection_domain *domain)
{
	struct iommu_dev_data *dev_data;

	list_for_each_entry(dev_data, &domain->dev_list, list)
		device_flush_dte(dev_data);
}

/****************************************************************************
 *
 * The functions below are used the create the page table mappings for
 * unity mapped regions.
 *
 ****************************************************************************/

static void free_page_list(struct page *freelist)
{
	while (freelist != NULL) {
		unsigned long p = (unsigned long)page_address(freelist);
		freelist = freelist->freelist;
		free_page(p);
	}
}

static struct page *free_pt_page(unsigned long pt, struct page *freelist)
{
	struct page *p = virt_to_page((void *)pt);

	p->freelist = freelist;

	return p;
}

#define DEFINE_FREE_PT_FN(LVL, FN)						\
static struct page *free_pt_##LVL (unsigned long __pt, struct page *freelist)	\
{										\
	unsigned long p;							\
	u64 *pt;								\
	int i;									\
										\
	pt = (u64 *)__pt;							\
										\
	for (i = 0; i < 512; ++i) {						\
		/* PTE present? */						\
		if (!IOMMU_PTE_PRESENT(pt[i]))					\
			continue;						\
										\
		/* Large PTE? */						\
		if (PM_PTE_LEVEL(pt[i]) == 0 ||					\
		    PM_PTE_LEVEL(pt[i]) == 7)					\
			continue;						\
										\
		p = (unsigned long)IOMMU_PTE_PAGE(pt[i]);			\
		freelist = FN(p, freelist);					\
	}									\
										\
	return free_pt_page((unsigned long)pt, freelist);			\
}

DEFINE_FREE_PT_FN(l2, free_pt_page)
DEFINE_FREE_PT_FN(l3, free_pt_l2)
DEFINE_FREE_PT_FN(l4, free_pt_l3)
DEFINE_FREE_PT_FN(l5, free_pt_l4)
DEFINE_FREE_PT_FN(l6, free_pt_l5)

static struct page *free_sub_pt(unsigned long root, int mode,
				struct page *freelist)
{
	switch (mode) {
	case PAGE_MODE_NONE:
	case PAGE_MODE_7_LEVEL:
		break;
	case PAGE_MODE_1_LEVEL:
		freelist = free_pt_page(root, freelist);
		break;
	case PAGE_MODE_2_LEVEL:
		freelist = free_pt_l2(root, freelist);
		break;
	case PAGE_MODE_3_LEVEL:
		freelist = free_pt_l3(root, freelist);
		break;
	case PAGE_MODE_4_LEVEL:
		freelist = free_pt_l4(root, freelist);
		break;
	case PAGE_MODE_5_LEVEL:
		freelist = free_pt_l5(root, freelist);
		break;
	case PAGE_MODE_6_LEVEL:
		freelist = free_pt_l6(root, freelist);
		break;
	default:
		BUG();
	}

	return freelist;
}

static void free_pagetable(struct domain_pgtable *pgtable)
{
	struct page *freelist = NULL;
	unsigned long root;

	if (pgtable->mode == PAGE_MODE_NONE)
		return;

	BUG_ON(pgtable->mode < PAGE_MODE_NONE ||
	       pgtable->mode > PAGE_MODE_6_LEVEL);

	root = (unsigned long)pgtable->root;
	freelist = free_sub_pt(root, pgtable->mode, freelist);

	free_page_list(freelist);
}

/*
 * This function is used to add another level to an IO page table. Adding
 * another level increases the size of the address space by 9 bits to a size up
 * to 64 bits.
 */
static bool increase_address_space(struct protection_domain *domain,
				   unsigned long address,
				   gfp_t gfp)
{
	struct domain_pgtable pgtable;
	unsigned long flags;
	bool ret = true;
	u64 *pte, root;

	spin_lock_irqsave(&domain->lock, flags);

	amd_iommu_domain_get_pgtable(domain, &pgtable);

	if (address <= PM_LEVEL_SIZE(pgtable.mode))
		goto out;

	ret = false;
	if (WARN_ON_ONCE(pgtable.mode == PAGE_MODE_6_LEVEL))
		goto out;

	pte = (void *)get_zeroed_page(gfp);
	if (!pte)
		goto out;

	*pte = PM_LEVEL_PDE(pgtable.mode, iommu_virt_to_phys(pgtable.root));

	pgtable.root  = pte;
	pgtable.mode += 1;
	update_and_flush_device_table(domain, &pgtable);
	domain_flush_complete(domain);

	/*
	 * Device Table needs to be updated and flushed before the new root can
	 * be published.
	 */
	root = amd_iommu_domain_encode_pgtable(pte, pgtable.mode);
	atomic64_set(&domain->pt_root, root);

	ret = true;

out:
	spin_unlock_irqrestore(&domain->lock, flags);

	return ret;
}

static u64 *alloc_pte(struct protection_domain *domain,
		      unsigned long address,
		      unsigned long page_size,
		      u64 **pte_page,
		      gfp_t gfp,
		      bool *updated)
{
	struct domain_pgtable pgtable;
	int level, end_lvl;
	u64 *pte, *page;

	BUG_ON(!is_power_of_2(page_size));

	amd_iommu_domain_get_pgtable(domain, &pgtable);

	while (address > PM_LEVEL_SIZE(pgtable.mode)) {
		/*
		 * Return an error if there is no memory to update the
		 * page-table.
		 */
		if (!increase_address_space(domain, address, gfp))
			return NULL;

		/* Read new values to check if update was successful */
		amd_iommu_domain_get_pgtable(domain, &pgtable);
	}


	level   = pgtable.mode - 1;
	pte     = &pgtable.root[PM_LEVEL_INDEX(level, address)];
	address = PAGE_SIZE_ALIGN(address, page_size);
	end_lvl = PAGE_SIZE_LEVEL(page_size);

	while (level > end_lvl) {
		u64 __pte, __npte;
		int pte_level;

		__pte     = *pte;
		pte_level = PM_PTE_LEVEL(__pte);

		/*
		 * If we replace a series of large PTEs, we need
		 * to tear down all of them.
		 */
		if (IOMMU_PTE_PRESENT(__pte) &&
		    pte_level == PAGE_MODE_7_LEVEL) {
			unsigned long count, i;
			u64 *lpte;

			lpte = first_pte_l7(pte, NULL, &count);

			/*
			 * Unmap the replicated PTEs that still match the
			 * original large mapping
			 */
			for (i = 0; i < count; ++i)
				cmpxchg64(&lpte[i], __pte, 0ULL);

			*updated = true;
			continue;
		}

		if (!IOMMU_PTE_PRESENT(__pte) ||
		    pte_level == PAGE_MODE_NONE) {
			page = (u64 *)get_zeroed_page(gfp);

			if (!page)
				return NULL;

			__npte = PM_LEVEL_PDE(level, iommu_virt_to_phys(page));

			/* pte could have been changed somewhere. */
			if (cmpxchg64(pte, __pte, __npte) != __pte)
				free_page((unsigned long)page);
			else if (IOMMU_PTE_PRESENT(__pte))
				*updated = true;

			continue;
		}

		/* No level skipping support yet */
		if (pte_level != level)
			return NULL;

		level -= 1;

		pte = IOMMU_PTE_PAGE(__pte);

		if (pte_page && level == end_lvl)
			*pte_page = pte;

		pte = &pte[PM_LEVEL_INDEX(level, address)];
	}

	return pte;
}

/*
 * This function checks if there is a PTE for a given dma address. If
 * there is one, it returns the pointer to it.
 */
static u64 *fetch_pte(struct protection_domain *domain,
		      unsigned long address,
		      unsigned long *page_size)
{
	struct domain_pgtable pgtable;
	int level;
	u64 *pte;

	*page_size = 0;

	amd_iommu_domain_get_pgtable(domain, &pgtable);

	if (address > PM_LEVEL_SIZE(pgtable.mode))
		return NULL;

	level	   =  pgtable.mode - 1;
	pte	   = &pgtable.root[PM_LEVEL_INDEX(level, address)];
	*page_size =  PTE_LEVEL_PAGE_SIZE(level);

	while (level > 0) {

		/* Not Present */
		if (!IOMMU_PTE_PRESENT(*pte))
			return NULL;

		/* Large PTE */
		if (PM_PTE_LEVEL(*pte) == 7 ||
		    PM_PTE_LEVEL(*pte) == 0)
			break;

		/* No level skipping support yet */
		if (PM_PTE_LEVEL(*pte) != level)
			return NULL;

		level -= 1;

		/* Walk to the next level */
		pte	   = IOMMU_PTE_PAGE(*pte);
		pte	   = &pte[PM_LEVEL_INDEX(level, address)];
		*page_size = PTE_LEVEL_PAGE_SIZE(level);
	}

	/*
	 * If we have a series of large PTEs, make
	 * sure to return a pointer to the first one.
	 */
	if (PM_PTE_LEVEL(*pte) == PAGE_MODE_7_LEVEL)
		pte = first_pte_l7(pte, page_size, NULL);

	return pte;
}

static struct page *free_clear_pte(u64 *pte, u64 pteval, struct page *freelist)
{
	unsigned long pt;
	int mode;

	while (cmpxchg64(pte, pteval, 0) != pteval) {
		pr_warn("AMD-Vi: IOMMU pte changed since we read it\n");
		pteval = *pte;
	}

	if (!IOMMU_PTE_PRESENT(pteval))
		return freelist;

	pt   = (unsigned long)IOMMU_PTE_PAGE(pteval);
	mode = IOMMU_PTE_MODE(pteval);

	return free_sub_pt(pt, mode, freelist);
}

/*
 * Generic mapping functions. It maps a physical address into a DMA
 * address space. It allocates the page table pages if necessary.
 * In the future it can be extended to a generic mapping function
 * supporting all features of AMD IOMMU page tables like level skipping
 * and full 64 bit address spaces.
 */
static int iommu_map_page(struct protection_domain *dom,
			  unsigned long bus_addr,
			  unsigned long phys_addr,
			  unsigned long page_size,
			  int prot,
			  gfp_t gfp)
{
	struct page *freelist = NULL;
	bool updated = false;
	u64 __pte, *pte;
	int ret, i, count;

	BUG_ON(!IS_ALIGNED(bus_addr, page_size));
	BUG_ON(!IS_ALIGNED(phys_addr, page_size));

	ret = -EINVAL;
	if (!(prot & IOMMU_PROT_MASK))
		goto out;

	count = PAGE_SIZE_PTE_COUNT(page_size);
	pte   = alloc_pte(dom, bus_addr, page_size, NULL, gfp, &updated);

	ret = -ENOMEM;
	if (!pte)
		goto out;

	for (i = 0; i < count; ++i)
		freelist = free_clear_pte(&pte[i], pte[i], freelist);

	if (freelist != NULL)
		updated = true;

	if (count > 1) {
		__pte = PAGE_SIZE_PTE(__sme_set(phys_addr), page_size);
		__pte |= PM_LEVEL_ENC(7) | IOMMU_PTE_PR | IOMMU_PTE_FC;
	} else
		__pte = __sme_set(phys_addr) | IOMMU_PTE_PR | IOMMU_PTE_FC;

	if (prot & IOMMU_PROT_IR)
		__pte |= IOMMU_PTE_IR;
	if (prot & IOMMU_PROT_IW)
		__pte |= IOMMU_PTE_IW;

	for (i = 0; i < count; ++i)
		pte[i] = __pte;

	ret = 0;

out:
	if (updated) {
		unsigned long flags;

		spin_lock_irqsave(&dom->lock, flags);
		/*
		 * Flush domain TLB(s) and wait for completion. Any Device-Table
		 * Updates and flushing already happened in
		 * increase_address_space().
		 */
		domain_flush_tlb_pde(dom);
		domain_flush_complete(dom);
		spin_unlock_irqrestore(&dom->lock, flags);
	}

	/* Everything flushed out, free pages now */
	free_page_list(freelist);

	return ret;
}

static unsigned long iommu_unmap_page(struct protection_domain *dom,
				      unsigned long bus_addr,
				      unsigned long page_size)
{
	unsigned long long unmapped;
	unsigned long unmap_size;
	u64 *pte;

	BUG_ON(!is_power_of_2(page_size));

	unmapped = 0;

	while (unmapped < page_size) {

		pte = fetch_pte(dom, bus_addr, &unmap_size);

		if (pte) {
			int i, count;

			count = PAGE_SIZE_PTE_COUNT(unmap_size);
			for (i = 0; i < count; i++)
				pte[i] = 0ULL;
		}

		bus_addr  = (bus_addr & ~(unmap_size - 1)) + unmap_size;
		unmapped += unmap_size;
	}

	BUG_ON(unmapped && !is_power_of_2(unmapped));

	return unmapped;
}

/****************************************************************************
 *
 * The next functions belong to the domain allocation. A domain is
 * allocated for every IOMMU as the default domain. If device isolation
 * is enabled, every device get its own domain. The most important thing
 * about domains is the page table mapping the DMA address space they
 * contain.
 *
 ****************************************************************************/

static u16 domain_id_alloc(void)
{
	int id;

	spin_lock(&pd_bitmap_lock);
	id = find_first_zero_bit(amd_iommu_pd_alloc_bitmap, MAX_DOMAIN_ID);
	BUG_ON(id == 0);
	if (id > 0 && id < MAX_DOMAIN_ID)
		__set_bit(id, amd_iommu_pd_alloc_bitmap);
	else
		id = 0;
	spin_unlock(&pd_bitmap_lock);

	return id;
}

static void domain_id_free(int id)
{
	spin_lock(&pd_bitmap_lock);
	if (id > 0 && id < MAX_DOMAIN_ID)
		__clear_bit(id, amd_iommu_pd_alloc_bitmap);
	spin_unlock(&pd_bitmap_lock);
}

static void free_gcr3_tbl_level1(u64 *tbl)
{
	u64 *ptr;
	int i;

	for (i = 0; i < 512; ++i) {
		if (!(tbl[i] & GCR3_VALID))
			continue;

		ptr = iommu_phys_to_virt(tbl[i] & PAGE_MASK);

		free_page((unsigned long)ptr);
	}
}

static void free_gcr3_tbl_level2(u64 *tbl)
{
	u64 *ptr;
	int i;

	for (i = 0; i < 512; ++i) {
		if (!(tbl[i] & GCR3_VALID))
			continue;

		ptr = iommu_phys_to_virt(tbl[i] & PAGE_MASK);

		free_gcr3_tbl_level1(ptr);
	}
}

static void free_gcr3_table(struct protection_domain *domain)
{
	if (domain->glx == 2)
		free_gcr3_tbl_level2(domain->gcr3_tbl);
	else if (domain->glx == 1)
		free_gcr3_tbl_level1(domain->gcr3_tbl);
	else
		BUG_ON(domain->glx != 0);

	free_page((unsigned long)domain->gcr3_tbl);
}

static void set_dte_entry(u16 devid, struct protection_domain *domain,
			  struct domain_pgtable *pgtable,
			  bool ats, bool ppr)
{
	u64 pte_root = 0;
	u64 flags = 0;
	u32 old_domid;

	if (pgtable->mode != PAGE_MODE_NONE)
		pte_root = iommu_virt_to_phys(pgtable->root);

	pte_root |= (pgtable->mode & DEV_ENTRY_MODE_MASK)
		    << DEV_ENTRY_MODE_SHIFT;
	pte_root |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_V | DTE_FLAG_TV;

	flags = amd_iommu_dev_table[devid].data[1];

	if (ats)
		flags |= DTE_FLAG_IOTLB;

	if (ppr) {
		struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];

		if (iommu_feature(iommu, FEATURE_EPHSUP))
			pte_root |= 1ULL << DEV_ENTRY_PPR;
	}

	if (domain->flags & PD_IOMMUV2_MASK) {
		u64 gcr3 = iommu_virt_to_phys(domain->gcr3_tbl);
		u64 glx  = domain->glx;
		u64 tmp;

		pte_root |= DTE_FLAG_GV;
		pte_root |= (glx & DTE_GLX_MASK) << DTE_GLX_SHIFT;

		/* First mask out possible old values for GCR3 table */
		tmp = DTE_GCR3_VAL_B(~0ULL) << DTE_GCR3_SHIFT_B;
		flags    &= ~tmp;

		tmp = DTE_GCR3_VAL_C(~0ULL) << DTE_GCR3_SHIFT_C;
		flags    &= ~tmp;

		/* Encode GCR3 table into DTE */
		tmp = DTE_GCR3_VAL_A(gcr3) << DTE_GCR3_SHIFT_A;
		pte_root |= tmp;

		tmp = DTE_GCR3_VAL_B(gcr3) << DTE_GCR3_SHIFT_B;
		flags    |= tmp;

		tmp = DTE_GCR3_VAL_C(gcr3) << DTE_GCR3_SHIFT_C;
		flags    |= tmp;
	}

	flags &= ~DEV_DOMID_MASK;
	flags |= domain->id;

	old_domid = amd_iommu_dev_table[devid].data[1] & DEV_DOMID_MASK;
	amd_iommu_dev_table[devid].data[1]  = flags;
	amd_iommu_dev_table[devid].data[0]  = pte_root;

	/*
	 * A kdump kernel might be replacing a domain ID that was copied from
	 * the previous kernel--if so, it needs to flush the translation cache
	 * entries for the old domain ID that is being overwritten
	 */
	if (old_domid) {
		struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];

		amd_iommu_flush_tlb_domid(iommu, old_domid);
	}
}

static void clear_dte_entry(u16 devid)
{
	/* remove entry from the device table seen by the hardware */
	amd_iommu_dev_table[devid].data[0]  = DTE_FLAG_V | DTE_FLAG_TV;
	amd_iommu_dev_table[devid].data[1] &= DTE_FLAG_MASK;

	amd_iommu_apply_erratum_63(devid);
}

static void do_attach(struct iommu_dev_data *dev_data,
		      struct protection_domain *domain)
{
	struct domain_pgtable pgtable;
	struct amd_iommu *iommu;
	bool ats;

	iommu = amd_iommu_rlookup_table[dev_data->devid];
	ats   = dev_data->ats.enabled;

	/* Update data structures */
	dev_data->domain = domain;
	list_add(&dev_data->list, &domain->dev_list);

	/* Do reference counting */
	domain->dev_iommu[iommu->index] += 1;
	domain->dev_cnt                 += 1;

	/* Update device table */
	amd_iommu_domain_get_pgtable(domain, &pgtable);
	set_dte_entry(dev_data->devid, domain, &pgtable,
		      ats, dev_data->iommu_v2);
	clone_aliases(dev_data->pdev);

	device_flush_dte(dev_data);
}

static void do_detach(struct iommu_dev_data *dev_data)
{
	struct protection_domain *domain = dev_data->domain;
	struct amd_iommu *iommu;

	iommu = amd_iommu_rlookup_table[dev_data->devid];

	/* Update data structures */
	dev_data->domain = NULL;
	list_del(&dev_data->list);
	clear_dte_entry(dev_data->devid);
	clone_aliases(dev_data->pdev);

	/* Flush the DTE entry */
	device_flush_dte(dev_data);

	/* Flush IOTLB */
	domain_flush_tlb_pde(domain);

	/* Wait for the flushes to finish */
	domain_flush_complete(domain);

	/* decrease reference counters - needs to happen after the flushes */
	domain->dev_iommu[iommu->index] -= 1;
	domain->dev_cnt                 -= 1;
}

static void pdev_iommuv2_disable(struct pci_dev *pdev)
{
	pci_disable_ats(pdev);
	pci_disable_pri(pdev);
	pci_disable_pasid(pdev);
}

/* FIXME: Change generic reset-function to do the same */
static int pri_reset_while_enabled(struct pci_dev *pdev)
{
	u16 control;
	int pos;

	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
	if (!pos)
		return -EINVAL;

	pci_read_config_word(pdev, pos + PCI_PRI_CTRL, &control);
	control |= PCI_PRI_CTRL_RESET;
	pci_write_config_word(pdev, pos + PCI_PRI_CTRL, control);

	return 0;
}

static int pdev_iommuv2_enable(struct pci_dev *pdev)
{
	bool reset_enable;
	int reqs, ret;

	/* FIXME: Hardcode number of outstanding requests for now */
	reqs = 32;
	if (pdev_pri_erratum(pdev, AMD_PRI_DEV_ERRATUM_LIMIT_REQ_ONE))
		reqs = 1;
	reset_enable = pdev_pri_erratum(pdev, AMD_PRI_DEV_ERRATUM_ENABLE_RESET);

	/* Only allow access to user-accessible pages */
	ret = pci_enable_pasid(pdev, 0);
	if (ret)
		goto out_err;

	/* First reset the PRI state of the device */
	ret = pci_reset_pri(pdev);
	if (ret)
		goto out_err;

	/* Enable PRI */
	ret = pci_enable_pri(pdev, reqs);
	if (ret)
		goto out_err;

	if (reset_enable) {
		ret = pri_reset_while_enabled(pdev);
		if (ret)
			goto out_err;
	}

	ret = pci_enable_ats(pdev, PAGE_SHIFT);
	if (ret)
		goto out_err;

	return 0;

out_err:
	pci_disable_pri(pdev);
	pci_disable_pasid(pdev);

	return ret;
}

/*
 * If a device is not yet associated with a domain, this function makes the
 * device visible in the domain
 */
static int attach_device(struct device *dev,
			 struct protection_domain *domain)
{
	struct iommu_dev_data *dev_data;
	struct pci_dev *pdev;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&domain->lock, flags);

	dev_data = dev_iommu_priv_get(dev);

	spin_lock(&dev_data->lock);

	ret = -EBUSY;
	if (dev_data->domain != NULL)
		goto out;

	if (!dev_is_pci(dev))
		goto skip_ats_check;

	pdev = to_pci_dev(dev);
	if (domain->flags & PD_IOMMUV2_MASK) {
		struct iommu_domain *def_domain = iommu_get_dma_domain(dev);

		ret = -EINVAL;
		if (def_domain->type != IOMMU_DOMAIN_IDENTITY)
			goto out;

		if (dev_data->iommu_v2) {
			if (pdev_iommuv2_enable(pdev) != 0)
				goto out;

			dev_data->ats.enabled = true;
			dev_data->ats.qdep    = pci_ats_queue_depth(pdev);
			dev_data->pri_tlp     = pci_prg_resp_pasid_required(pdev);
		}
	} else if (amd_iommu_iotlb_sup &&
		   pci_enable_ats(pdev, PAGE_SHIFT) == 0) {
		dev_data->ats.enabled = true;
		dev_data->ats.qdep    = pci_ats_queue_depth(pdev);
	}

skip_ats_check:
	ret = 0;

	do_attach(dev_data, domain);

	/*
	 * We might boot into a crash-kernel here. The crashed kernel
	 * left the caches in the IOMMU dirty. So we have to flush
	 * here to evict all dirty stuff.
	 */
	domain_flush_tlb_pde(domain);

	domain_flush_complete(domain);

out:
	spin_unlock(&dev_data->lock);

	spin_unlock_irqrestore(&domain->lock, flags);

	return ret;
}

/*
 * Removes a device from a protection domain (with devtable_lock held)
 */
static void detach_device(struct device *dev)
{
	struct protection_domain *domain;
	struct iommu_dev_data *dev_data;
	unsigned long flags;

	dev_data = dev_iommu_priv_get(dev);
	domain   = dev_data->domain;

	spin_lock_irqsave(&domain->lock, flags);

	spin_lock(&dev_data->lock);

	/*
	 * First check if the device is still attached. It might already
	 * be detached from its domain because the generic
	 * iommu_detach_group code detached it and we try again here in
	 * our alias handling.
	 */
	if (WARN_ON(!dev_data->domain))
		goto out;

	do_detach(dev_data);

	if (!dev_is_pci(dev))
		goto out;

	if (domain->flags & PD_IOMMUV2_MASK && dev_data->iommu_v2)
		pdev_iommuv2_disable(to_pci_dev(dev));
	else if (dev_data->ats.enabled)
		pci_disable_ats(to_pci_dev(dev));

	dev_data->ats.enabled = false;

out:
	spin_unlock(&dev_data->lock);

	spin_unlock_irqrestore(&domain->lock, flags);
}

static struct iommu_device *amd_iommu_probe_device(struct device *dev)
{
	struct iommu_device *iommu_dev;
	struct amd_iommu *iommu;
	int ret, devid;

	if (!check_device(dev))
		return ERR_PTR(-ENODEV);

	devid = get_device_id(dev);
	if (devid < 0)
		return ERR_PTR(devid);

	iommu = amd_iommu_rlookup_table[devid];

	if (dev_iommu_priv_get(dev))
		return &iommu->iommu;

	ret = iommu_init_device(dev);
	if (ret) {
		if (ret != -ENOTSUPP)
			dev_err(dev, "Failed to initialize - trying to proceed anyway\n");
		iommu_dev = ERR_PTR(ret);
		iommu_ignore_device(dev);
	} else {
		iommu_dev = &iommu->iommu;
	}

	iommu_completion_wait(iommu);

	return iommu_dev;
}

static void amd_iommu_probe_finalize(struct device *dev)
{
	struct iommu_domain *domain;

	/* Domains are initialized for this device - have a look what we ended up with */
	domain = iommu_get_domain_for_dev(dev);
	if (domain->type == IOMMU_DOMAIN_DMA)
		iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, 0);
}

static void amd_iommu_release_device(struct device *dev)
{
	int devid = get_device_id(dev);
	struct amd_iommu *iommu;

	if (!check_device(dev))
		return;

	iommu = amd_iommu_rlookup_table[devid];

	amd_iommu_uninit_device(dev);
	iommu_completion_wait(iommu);
}

static struct iommu_group *amd_iommu_device_group(struct device *dev)
{
	if (dev_is_pci(dev))
		return pci_device_group(dev);

	return acpihid_device_group(dev);
}

static int amd_iommu_domain_get_attr(struct iommu_domain *domain,
		enum iommu_attr attr, void *data)
{
	switch (domain->type) {
	case IOMMU_DOMAIN_UNMANAGED:
		return -ENODEV;
	case IOMMU_DOMAIN_DMA:
		switch (attr) {
		case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
			*(int *)data = !amd_iommu_unmap_flush;
			return 0;
		default:
			return -ENODEV;
		}
		break;
	default:
		return -EINVAL;
	}
}

/*****************************************************************************
 *
 * The next functions belong to the dma_ops mapping/unmapping code.
 *
 *****************************************************************************/

static void update_device_table(struct protection_domain *domain,
				struct domain_pgtable *pgtable)
{
	struct iommu_dev_data *dev_data;

	list_for_each_entry(dev_data, &domain->dev_list, list) {
		set_dte_entry(dev_data->devid, domain, pgtable,
			      dev_data->ats.enabled, dev_data->iommu_v2);
		clone_aliases(dev_data->pdev);
	}
}

static void update_and_flush_device_table(struct protection_domain *domain,
					  struct domain_pgtable *pgtable)
{
	update_device_table(domain, pgtable);
	domain_flush_devices(domain);
}

static void update_domain(struct protection_domain *domain)
{
	struct domain_pgtable pgtable;

	/* Update device table */
	amd_iommu_domain_get_pgtable(domain, &pgtable);
	update_and_flush_device_table(domain, &pgtable);

	/* Flush domain TLB(s) and wait for completion */
	domain_flush_tlb_pde(domain);
	domain_flush_complete(domain);
}

int __init amd_iommu_init_api(void)
{
	int ret, err = 0;

	ret = iova_cache_get();
	if (ret)
		return ret;

	err = bus_set_iommu(&pci_bus_type, &amd_iommu_ops);
	if (err)
		return err;
#ifdef CONFIG_ARM_AMBA
	err = bus_set_iommu(&amba_bustype, &amd_iommu_ops);
	if (err)
		return err;
#endif
	err = bus_set_iommu(&platform_bus_type, &amd_iommu_ops);
	if (err)
		return err;

	return 0;
}

int __init amd_iommu_init_dma_ops(void)
{
	swiotlb        = (iommu_default_passthrough() || sme_me_mask) ? 1 : 0;

	if (amd_iommu_unmap_flush)
		pr_info("IO/TLB flush on unmap enabled\n");
	else
		pr_info("Lazy IO/TLB flushing enabled\n");

	return 0;

}

/*****************************************************************************
 *
 * The following functions belong to the exported interface of AMD IOMMU
 *
 * This interface allows access to lower level functions of the IOMMU
 * like protection domain handling and assignement of devices to domains
 * which is not possible with the dma_ops interface.
 *
 *****************************************************************************/

static void cleanup_domain(struct protection_domain *domain)
{
	struct iommu_dev_data *entry;
	unsigned long flags;

	spin_lock_irqsave(&domain->lock, flags);

	while (!list_empty(&domain->dev_list)) {
		entry = list_first_entry(&domain->dev_list,
					 struct iommu_dev_data, list);
		BUG_ON(!entry->domain);
		do_detach(entry);
	}

	spin_unlock_irqrestore(&domain->lock, flags);
}

static void protection_domain_free(struct protection_domain *domain)
{
	struct domain_pgtable pgtable;

	if (!domain)
		return;

	if (domain->id)
		domain_id_free(domain->id);

	amd_iommu_domain_get_pgtable(domain, &pgtable);
	atomic64_set(&domain->pt_root, 0);
	free_pagetable(&pgtable);

	kfree(domain);
}

static int protection_domain_init(struct protection_domain *domain, int mode)
{
	u64 *pt_root = NULL, root;

	BUG_ON(mode < PAGE_MODE_NONE || mode > PAGE_MODE_6_LEVEL);

	spin_lock_init(&domain->lock);
	domain->id = domain_id_alloc();
	if (!domain->id)
		return -ENOMEM;
	INIT_LIST_HEAD(&domain->dev_list);

	if (mode != PAGE_MODE_NONE) {
		pt_root = (void *)get_zeroed_page(GFP_KERNEL);
		if (!pt_root)
			return -ENOMEM;
	}

	root = amd_iommu_domain_encode_pgtable(pt_root, mode);
	atomic64_set(&domain->pt_root, root);

	return 0;
}

static struct protection_domain *protection_domain_alloc(int mode)
{
	struct protection_domain *domain;

	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
	if (!domain)
		return NULL;

	if (protection_domain_init(domain, mode))
		goto out_err;

	return domain;

out_err:
	kfree(domain);

	return NULL;
}

static struct iommu_domain *amd_iommu_domain_alloc(unsigned type)
{
	struct protection_domain *domain;
	int mode = DEFAULT_PGTABLE_LEVEL;

	if (type == IOMMU_DOMAIN_IDENTITY)
		mode = PAGE_MODE_NONE;

	domain = protection_domain_alloc(mode);
	if (!domain)
		return NULL;

	domain->domain.geometry.aperture_start = 0;
	domain->domain.geometry.aperture_end   = ~0ULL;
	domain->domain.geometry.force_aperture = true;

	if (type == IOMMU_DOMAIN_DMA &&
	    iommu_get_dma_cookie(&domain->domain) == -ENOMEM)
		goto free_domain;

	return &domain->domain;

free_domain:
	protection_domain_free(domain);

	return NULL;
}

static void amd_iommu_domain_free(struct iommu_domain *dom)
{
	struct protection_domain *domain;

	domain = to_pdomain(dom);

	if (domain->dev_cnt > 0)
		cleanup_domain(domain);

	BUG_ON(domain->dev_cnt != 0);

	if (!dom)
		return;

	if (dom->type == IOMMU_DOMAIN_DMA)
		iommu_put_dma_cookie(&domain->domain);

	if (domain->flags & PD_IOMMUV2_MASK)
		free_gcr3_table(domain);

	protection_domain_free(domain);
}

static void amd_iommu_detach_device(struct iommu_domain *dom,
				    struct device *dev)
{
	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
	struct amd_iommu *iommu;
	int devid;

	if (!check_device(dev))
		return;

	devid = get_device_id(dev);
	if (devid < 0)
		return;

	if (dev_data->domain != NULL)
		detach_device(dev);

	iommu = amd_iommu_rlookup_table[devid];
	if (!iommu)
		return;

#ifdef CONFIG_IRQ_REMAP
	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
	    (dom->type == IOMMU_DOMAIN_UNMANAGED))
		dev_data->use_vapic = 0;
#endif

	iommu_completion_wait(iommu);
}

static int amd_iommu_attach_device(struct iommu_domain *dom,
				   struct device *dev)
{
	struct protection_domain *domain = to_pdomain(dom);
	struct iommu_dev_data *dev_data;
	struct amd_iommu *iommu;
	int ret;

	if (!check_device(dev))
		return -EINVAL;

	dev_data = dev_iommu_priv_get(dev);
	dev_data->defer_attach = false;

	iommu = amd_iommu_rlookup_table[dev_data->devid];
	if (!iommu)
		return -EINVAL;

	if (dev_data->domain)
		detach_device(dev);

	ret = attach_device(dev, domain);

#ifdef CONFIG_IRQ_REMAP
	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir)) {
		if (dom->type == IOMMU_DOMAIN_UNMANAGED)
			dev_data->use_vapic = 1;
		else
			dev_data->use_vapic = 0;
	}
#endif

	iommu_completion_wait(iommu);

	return ret;
}

static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
			 phys_addr_t paddr, size_t page_size, int iommu_prot,
			 gfp_t gfp)
{
	struct protection_domain *domain = to_pdomain(dom);
	struct domain_pgtable pgtable;
	int prot = 0;
	int ret;

	amd_iommu_domain_get_pgtable(domain, &pgtable);
	if (pgtable.mode == PAGE_MODE_NONE)
		return -EINVAL;

	if (iommu_prot & IOMMU_READ)
		prot |= IOMMU_PROT_IR;
	if (iommu_prot & IOMMU_WRITE)
		prot |= IOMMU_PROT_IW;

	ret = iommu_map_page(domain, iova, paddr, page_size, prot, gfp);

	domain_flush_np_cache(domain, iova, page_size);

	return ret;
}

static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
			      size_t page_size,
			      struct iommu_iotlb_gather *gather)
{
	struct protection_domain *domain = to_pdomain(dom);
	struct domain_pgtable pgtable;

	amd_iommu_domain_get_pgtable(domain, &pgtable);
	if (pgtable.mode == PAGE_MODE_NONE)
		return 0;

	return iommu_unmap_page(domain, iova, page_size);
}

static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
					  dma_addr_t iova)
{
	struct protection_domain *domain = to_pdomain(dom);
	unsigned long offset_mask, pte_pgsize;
	struct domain_pgtable pgtable;
	u64 *pte, __pte;

	amd_iommu_domain_get_pgtable(domain, &pgtable);
	if (pgtable.mode == PAGE_MODE_NONE)
		return iova;

	pte = fetch_pte(domain, iova, &pte_pgsize);

	if (!pte || !IOMMU_PTE_PRESENT(*pte))
		return 0;

	offset_mask = pte_pgsize - 1;
	__pte	    = __sme_clr(*pte & PM_ADDR_MASK);

	return (__pte & ~offset_mask) | (iova & offset_mask);
}

static bool amd_iommu_capable(enum iommu_cap cap)
{
	switch (cap) {
	case IOMMU_CAP_CACHE_COHERENCY:
		return true;
	case IOMMU_CAP_INTR_REMAP:
		return (irq_remapping_enabled == 1);
	case IOMMU_CAP_NOEXEC:
		return false;
	default:
		break;
	}

	return false;
}

static void amd_iommu_get_resv_regions(struct device *dev,
				       struct list_head *head)
{
	struct iommu_resv_region *region;
	struct unity_map_entry *entry;
	int devid;

	devid = get_device_id(dev);
	if (devid < 0)
		return;

	list_for_each_entry(entry, &amd_iommu_unity_map, list) {
		int type, prot = 0;
		size_t length;

		if (devid < entry->devid_start || devid > entry->devid_end)
			continue;

		type   = IOMMU_RESV_DIRECT;
		length = entry->address_end - entry->address_start;
		if (entry->prot & IOMMU_PROT_IR)
			prot |= IOMMU_READ;
		if (entry->prot & IOMMU_PROT_IW)
			prot |= IOMMU_WRITE;
		if (entry->prot & IOMMU_UNITY_MAP_FLAG_EXCL_RANGE)
			/* Exclusion range */
			type = IOMMU_RESV_RESERVED;

		region = iommu_alloc_resv_region(entry->address_start,
						 length, prot, type);
		if (!region) {
			dev_err(dev, "Out of memory allocating dm-regions\n");
			return;
		}
		list_add_tail(&region->list, head);
	}

	region = iommu_alloc_resv_region(MSI_RANGE_START,
					 MSI_RANGE_END - MSI_RANGE_START + 1,
					 0, IOMMU_RESV_MSI);
	if (!region)
		return;
	list_add_tail(&region->list, head);

	region = iommu_alloc_resv_region(HT_RANGE_START,
					 HT_RANGE_END - HT_RANGE_START + 1,
					 0, IOMMU_RESV_RESERVED);
	if (!region)
		return;
	list_add_tail(&region->list, head);
}

bool amd_iommu_is_attach_deferred(struct iommu_domain *domain,
				  struct device *dev)
{
	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);

	return dev_data->defer_attach;
}
EXPORT_SYMBOL_GPL(amd_iommu_is_attach_deferred);

static void amd_iommu_flush_iotlb_all(struct iommu_domain *domain)
{
	struct protection_domain *dom = to_pdomain(domain);
	unsigned long flags;

	spin_lock_irqsave(&dom->lock, flags);
	domain_flush_tlb_pde(dom);
	domain_flush_complete(dom);
	spin_unlock_irqrestore(&dom->lock, flags);
}

static void amd_iommu_iotlb_sync(struct iommu_domain *domain,
				 struct iommu_iotlb_gather *gather)
{
	amd_iommu_flush_iotlb_all(domain);
}

static int amd_iommu_def_domain_type(struct device *dev)
{
	struct iommu_dev_data *dev_data;

	dev_data = dev_iommu_priv_get(dev);
	if (!dev_data)
		return 0;

	if (dev_data->iommu_v2)
		return IOMMU_DOMAIN_IDENTITY;

	return 0;
}

const struct iommu_ops amd_iommu_ops = {
	.capable = amd_iommu_capable,
	.domain_alloc = amd_iommu_domain_alloc,
	.domain_free  = amd_iommu_domain_free,
	.attach_dev = amd_iommu_attach_device,
	.detach_dev = amd_iommu_detach_device,
	.map = amd_iommu_map,
	.unmap = amd_iommu_unmap,
	.iova_to_phys = amd_iommu_iova_to_phys,
	.probe_device = amd_iommu_probe_device,
	.release_device = amd_iommu_release_device,
	.probe_finalize = amd_iommu_probe_finalize,
	.device_group = amd_iommu_device_group,
	.domain_get_attr = amd_iommu_domain_get_attr,
	.get_resv_regions = amd_iommu_get_resv_regions,
	.put_resv_regions = generic_iommu_put_resv_regions,
	.is_attach_deferred = amd_iommu_is_attach_deferred,
	.pgsize_bitmap	= AMD_IOMMU_PGSIZES,
	.flush_iotlb_all = amd_iommu_flush_iotlb_all,
	.iotlb_sync = amd_iommu_iotlb_sync,
	.def_domain_type = amd_iommu_def_domain_type,
};

/*****************************************************************************
 *
 * The next functions do a basic initialization of IOMMU for pass through
 * mode
 *
 * In passthrough mode the IOMMU is initialized and enabled but not used for
 * DMA-API translation.
 *
 *****************************************************************************/

/* IOMMUv2 specific functions */
int amd_iommu_register_ppr_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_register(&ppr_notifier, nb);
}
EXPORT_SYMBOL(amd_iommu_register_ppr_notifier);

int amd_iommu_unregister_ppr_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_unregister(&ppr_notifier, nb);
}
EXPORT_SYMBOL(amd_iommu_unregister_ppr_notifier);

void amd_iommu_domain_direct_map(struct iommu_domain *dom)
{
	struct protection_domain *domain = to_pdomain(dom);
	struct domain_pgtable pgtable;
	unsigned long flags;

	spin_lock_irqsave(&domain->lock, flags);

	/* First save pgtable configuration*/
	amd_iommu_domain_get_pgtable(domain, &pgtable);

	/* Update data structure */
	atomic64_set(&domain->pt_root, 0);

	/* Make changes visible to IOMMUs */
	update_domain(domain);

	/* Page-table is not visible to IOMMU anymore, so free it */
	free_pagetable(&pgtable);

	spin_unlock_irqrestore(&domain->lock, flags);
}
EXPORT_SYMBOL(amd_iommu_domain_direct_map);

int amd_iommu_domain_enable_v2(struct iommu_domain *dom, int pasids)
{
	struct protection_domain *domain = to_pdomain(dom);
	unsigned long flags;
	int levels, ret;

	if (pasids <= 0 || pasids > (PASID_MASK + 1))
		return -EINVAL;

	/* Number of GCR3 table levels required */
	for (levels = 0; (pasids - 1) & ~0x1ff; pasids >>= 9)
		levels += 1;

	if (levels > amd_iommu_max_glx_val)
		return -EINVAL;

	spin_lock_irqsave(&domain->lock, flags);

	/*
	 * Save us all sanity checks whether devices already in the
	 * domain support IOMMUv2. Just force that the domain has no
	 * devices attached when it is switched into IOMMUv2 mode.
	 */
	ret = -EBUSY;
	if (domain->dev_cnt > 0 || domain->flags & PD_IOMMUV2_MASK)
		goto out;

	ret = -ENOMEM;
	domain->gcr3_tbl = (void *)get_zeroed_page(GFP_ATOMIC);
	if (domain->gcr3_tbl == NULL)
		goto out;

	domain->glx      = levels;
	domain->flags   |= PD_IOMMUV2_MASK;

	update_domain(domain);

	ret = 0;

out:
	spin_unlock_irqrestore(&domain->lock, flags);

	return ret;
}
EXPORT_SYMBOL(amd_iommu_domain_enable_v2);

static int __flush_pasid(struct protection_domain *domain, int pasid,
			 u64 address, bool size)
{
	struct iommu_dev_data *dev_data;
	struct iommu_cmd cmd;
	int i, ret;

	if (!(domain->flags & PD_IOMMUV2_MASK))
		return -EINVAL;

	build_inv_iommu_pasid(&cmd, domain->id, pasid, address, size);

	/*
	 * IOMMU TLB needs to be flushed before Device TLB to
	 * prevent device TLB refill from IOMMU TLB
	 */
	for (i = 0; i < amd_iommu_get_num_iommus(); ++i) {
		if (domain->dev_iommu[i] == 0)
			continue;

		ret = iommu_queue_command(amd_iommus[i], &cmd);
		if (ret != 0)
			goto out;
	}

	/* Wait until IOMMU TLB flushes are complete */
	domain_flush_complete(domain);

	/* Now flush device TLBs */
	list_for_each_entry(dev_data, &domain->dev_list, list) {
		struct amd_iommu *iommu;
		int qdep;

		/*
		   There might be non-IOMMUv2 capable devices in an IOMMUv2
		 * domain.
		 */
		if (!dev_data->ats.enabled)
			continue;

		qdep  = dev_data->ats.qdep;
		iommu = amd_iommu_rlookup_table[dev_data->devid];

		build_inv_iotlb_pasid(&cmd, dev_data->devid, pasid,
				      qdep, address, size);

		ret = iommu_queue_command(iommu, &cmd);
		if (ret != 0)
			goto out;
	}

	/* Wait until all device TLBs are flushed */
	domain_flush_complete(domain);

	ret = 0;

out:

	return ret;
}

static int __amd_iommu_flush_page(struct protection_domain *domain, int pasid,
				  u64 address)
{
	return __flush_pasid(domain, pasid, address, false);
}

int amd_iommu_flush_page(struct iommu_domain *dom, int pasid,
			 u64 address)
{
	struct protection_domain *domain = to_pdomain(dom);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&domain->lock, flags);
	ret = __amd_iommu_flush_page(domain, pasid, address);
	spin_unlock_irqrestore(&domain->lock, flags);

	return ret;
}
EXPORT_SYMBOL(amd_iommu_flush_page);

static int __amd_iommu_flush_tlb(struct protection_domain *domain, int pasid)
{
	return __flush_pasid(domain, pasid, CMD_INV_IOMMU_ALL_PAGES_ADDRESS,
			     true);
}

int amd_iommu_flush_tlb(struct iommu_domain *dom, int pasid)
{
	struct protection_domain *domain = to_pdomain(dom);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&domain->lock, flags);
	ret = __amd_iommu_flush_tlb(domain, pasid);
	spin_unlock_irqrestore(&domain->lock, flags);

	return ret;
}
EXPORT_SYMBOL(amd_iommu_flush_tlb);

static u64 *__get_gcr3_pte(u64 *root, int level, int pasid, bool alloc)
{
	int index;
	u64 *pte;

	while (true) {

		index = (pasid >> (9 * level)) & 0x1ff;
		pte   = &root[index];

		if (level == 0)
			break;

		if (!(*pte & GCR3_VALID)) {
			if (!alloc)
				return NULL;

			root = (void *)get_zeroed_page(GFP_ATOMIC);
			if (root == NULL)
				return NULL;

			*pte = iommu_virt_to_phys(root) | GCR3_VALID;
		}

		root = iommu_phys_to_virt(*pte & PAGE_MASK);

		level -= 1;
	}

	return pte;
}

static int __set_gcr3(struct protection_domain *domain, int pasid,
		      unsigned long cr3)
{
	struct domain_pgtable pgtable;
	u64 *pte;

	amd_iommu_domain_get_pgtable(domain, &pgtable);
	if (pgtable.mode != PAGE_MODE_NONE)
		return -EINVAL;

	pte = __get_gcr3_pte(domain->gcr3_tbl, domain->glx, pasid, true);
	if (pte == NULL)
		return -ENOMEM;

	*pte = (cr3 & PAGE_MASK) | GCR3_VALID;

	return __amd_iommu_flush_tlb(domain, pasid);
}

static int __clear_gcr3(struct protection_domain *domain, int pasid)
{
	struct domain_pgtable pgtable;
	u64 *pte;

	amd_iommu_domain_get_pgtable(domain, &pgtable);
	if (pgtable.mode != PAGE_MODE_NONE)
		return -EINVAL;

	pte = __get_gcr3_pte(domain->gcr3_tbl, domain->glx, pasid, false);
	if (pte == NULL)
		return 0;

	*pte = 0;

	return __amd_iommu_flush_tlb(domain, pasid);
}

int amd_iommu_domain_set_gcr3(struct iommu_domain *dom, int pasid,
			      unsigned long cr3)
{
	struct protection_domain *domain = to_pdomain(dom);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&domain->lock, flags);
	ret = __set_gcr3(domain, pasid, cr3);
	spin_unlock_irqrestore(&domain->lock, flags);

	return ret;
}
EXPORT_SYMBOL(amd_iommu_domain_set_gcr3);

int amd_iommu_domain_clear_gcr3(struct iommu_domain *dom, int pasid)
{
	struct protection_domain *domain = to_pdomain(dom);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&domain->lock, flags);
	ret = __clear_gcr3(domain, pasid);
	spin_unlock_irqrestore(&domain->lock, flags);

	return ret;
}
EXPORT_SYMBOL(amd_iommu_domain_clear_gcr3);

int amd_iommu_complete_ppr(struct pci_dev *pdev, int pasid,
			   int status, int tag)
{
	struct iommu_dev_data *dev_data;
	struct amd_iommu *iommu;
	struct iommu_cmd cmd;

	dev_data = dev_iommu_priv_get(&pdev->dev);
	iommu    = amd_iommu_rlookup_table[dev_data->devid];

	build_complete_ppr(&cmd, dev_data->devid, pasid, status,
			   tag, dev_data->pri_tlp);

	return iommu_queue_command(iommu, &cmd);
}
EXPORT_SYMBOL(amd_iommu_complete_ppr);

struct iommu_domain *amd_iommu_get_v2_domain(struct pci_dev *pdev)
{
	struct protection_domain *pdomain;
	struct iommu_dev_data *dev_data;
	struct device *dev = &pdev->dev;
	struct iommu_domain *io_domain;

	if (!check_device(dev))
		return NULL;

	dev_data  = dev_iommu_priv_get(&pdev->dev);
	pdomain   = dev_data->domain;
	io_domain = iommu_get_domain_for_dev(dev);

	if (pdomain == NULL && dev_data->defer_attach) {
		dev_data->defer_attach = false;
		pdomain = to_pdomain(io_domain);
		attach_device(dev, pdomain);
	}

	if (pdomain == NULL)
		return NULL;

	if (io_domain->type != IOMMU_DOMAIN_DMA)
		return NULL;

	/* Only return IOMMUv2 domains */
	if (!(pdomain->flags & PD_IOMMUV2_MASK))
		return NULL;

	return &pdomain->domain;
}
EXPORT_SYMBOL(amd_iommu_get_v2_domain);

void amd_iommu_enable_device_erratum(struct pci_dev *pdev, u32 erratum)
{
	struct iommu_dev_data *dev_data;

	if (!amd_iommu_v2_supported())
		return;

	dev_data = dev_iommu_priv_get(&pdev->dev);
	dev_data->errata |= (1 << erratum);
}
EXPORT_SYMBOL(amd_iommu_enable_device_erratum);

int amd_iommu_device_info(struct pci_dev *pdev,
                          struct amd_iommu_device_info *info)
{
	int max_pasids;
	int pos;

	if (pdev == NULL || info == NULL)
		return -EINVAL;

	if (!amd_iommu_v2_supported())
		return -EINVAL;

	memset(info, 0, sizeof(*info));

	if (pci_ats_supported(pdev))
		info->flags |= AMD_IOMMU_DEVICE_FLAG_ATS_SUP;

	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
	if (pos)
		info->flags |= AMD_IOMMU_DEVICE_FLAG_PRI_SUP;

	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
	if (pos) {
		int features;

		max_pasids = 1 << (9 * (amd_iommu_max_glx_val + 1));
		max_pasids = min(max_pasids, (1 << 20));

		info->flags |= AMD_IOMMU_DEVICE_FLAG_PASID_SUP;
		info->max_pasids = min(pci_max_pasids(pdev), max_pasids);

		features = pci_pasid_features(pdev);
		if (features & PCI_PASID_CAP_EXEC)
			info->flags |= AMD_IOMMU_DEVICE_FLAG_EXEC_SUP;
		if (features & PCI_PASID_CAP_PRIV)
			info->flags |= AMD_IOMMU_DEVICE_FLAG_PRIV_SUP;
	}

	return 0;
}
EXPORT_SYMBOL(amd_iommu_device_info);

#ifdef CONFIG_IRQ_REMAP

/*****************************************************************************
 *
 * Interrupt Remapping Implementation
 *
 *****************************************************************************/

static struct irq_chip amd_ir_chip;
static DEFINE_SPINLOCK(iommu_table_lock);

static void set_dte_irq_entry(u16 devid, struct irq_remap_table *table)
{
	u64 dte;

	dte	= amd_iommu_dev_table[devid].data[2];
	dte	&= ~DTE_IRQ_PHYS_ADDR_MASK;
	dte	|= iommu_virt_to_phys(table->table);
	dte	|= DTE_IRQ_REMAP_INTCTL;
	dte	|= DTE_IRQ_TABLE_LEN;
	dte	|= DTE_IRQ_REMAP_ENABLE;

	amd_iommu_dev_table[devid].data[2] = dte;
}

static struct irq_remap_table *get_irq_table(u16 devid)
{
	struct irq_remap_table *table;

	if (WARN_ONCE(!amd_iommu_rlookup_table[devid],
		      "%s: no iommu for devid %x\n", __func__, devid))
		return NULL;

	table = irq_lookup_table[devid];
	if (WARN_ONCE(!table, "%s: no table for devid %x\n", __func__, devid))
		return NULL;

	return table;
}

static struct irq_remap_table *__alloc_irq_table(void)
{
	struct irq_remap_table *table;

	table = kzalloc(sizeof(*table), GFP_KERNEL);
	if (!table)
		return NULL;

	table->table = kmem_cache_alloc(amd_iommu_irq_cache, GFP_KERNEL);
	if (!table->table) {
		kfree(table);
		return NULL;
	}
	raw_spin_lock_init(&table->lock);

	if (!AMD_IOMMU_GUEST_IR_GA(amd_iommu_guest_ir))
		memset(table->table, 0,
		       MAX_IRQS_PER_TABLE * sizeof(u32));
	else
		memset(table->table, 0,
		       (MAX_IRQS_PER_TABLE * (sizeof(u64) * 2)));
	return table;
}

static void set_remap_table_entry(struct amd_iommu *iommu, u16 devid,
				  struct irq_remap_table *table)
{
	irq_lookup_table[devid] = table;
	set_dte_irq_entry(devid, table);
	iommu_flush_dte(iommu, devid);
}

static int set_remap_table_entry_alias(struct pci_dev *pdev, u16 alias,
				       void *data)
{
	struct irq_remap_table *table = data;

	irq_lookup_table[alias] = table;
	set_dte_irq_entry(alias, table);

	iommu_flush_dte(amd_iommu_rlookup_table[alias], alias);

	return 0;
}

static struct irq_remap_table *alloc_irq_table(u16 devid, struct pci_dev *pdev)
{
	struct irq_remap_table *table = NULL;
	struct irq_remap_table *new_table = NULL;
	struct amd_iommu *iommu;
	unsigned long flags;
	u16 alias;

	spin_lock_irqsave(&iommu_table_lock, flags);

	iommu = amd_iommu_rlookup_table[devid];
	if (!iommu)
		goto out_unlock;

	table = irq_lookup_table[devid];
	if (table)
		goto out_unlock;

	alias = amd_iommu_alias_table[devid];
	table = irq_lookup_table[alias];
	if (table) {
		set_remap_table_entry(iommu, devid, table);
		goto out_wait;
	}
	spin_unlock_irqrestore(&iommu_table_lock, flags);

	/* Nothing there yet, allocate new irq remapping table */
	new_table = __alloc_irq_table();
	if (!new_table)
		return NULL;

	spin_lock_irqsave(&iommu_table_lock, flags);

	table = irq_lookup_table[devid];
	if (table)
		goto out_unlock;

	table = irq_lookup_table[alias];
	if (table) {
		set_remap_table_entry(iommu, devid, table);
		goto out_wait;
	}

	table = new_table;
	new_table = NULL;

	if (pdev)
		pci_for_each_dma_alias(pdev, set_remap_table_entry_alias,
				       table);
	else
		set_remap_table_entry(iommu, devid, table);

	if (devid != alias)
		set_remap_table_entry(iommu, alias, table);

out_wait:
	iommu_completion_wait(iommu);

out_unlock:
	spin_unlock_irqrestore(&iommu_table_lock, flags);

	if (new_table) {
		kmem_cache_free(amd_iommu_irq_cache, new_table->table);
		kfree(new_table);
	}
	return table;
}

static int alloc_irq_index(u16 devid, int count, bool align,
			   struct pci_dev *pdev)
{
	struct irq_remap_table *table;
	int index, c, alignment = 1;
	unsigned long flags;
	struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];

	if (!iommu)
		return -ENODEV;

	table = alloc_irq_table(devid, pdev);
	if (!table)
		return -ENODEV;

	if (align)
		alignment = roundup_pow_of_two(count);

	raw_spin_lock_irqsave(&table->lock, flags);

	/* Scan table for free entries */
	for (index = ALIGN(table->min_index, alignment), c = 0;
	     index < MAX_IRQS_PER_TABLE;) {
		if (!iommu->irte_ops->is_allocated(table, index)) {
			c += 1;
		} else {
			c     = 0;
			index = ALIGN(index + 1, alignment);
			continue;
		}

		if (c == count)	{
			for (; c != 0; --c)
				iommu->irte_ops->set_allocated(table, index - c + 1);

			index -= count - 1;
			goto out;
		}

		index++;
	}

	index = -ENOSPC;

out:
	raw_spin_unlock_irqrestore(&table->lock, flags);

	return index;
}

static int modify_irte_ga(u16 devid, int index, struct irte_ga *irte,
			  struct amd_ir_data *data)
{
	struct irq_remap_table *table;
	struct amd_iommu *iommu;
	unsigned long flags;
	struct irte_ga *entry;

	iommu = amd_iommu_rlookup_table[devid];
	if (iommu == NULL)
		return -EINVAL;

	table = get_irq_table(devid);
	if (!table)
		return -ENOMEM;

	raw_spin_lock_irqsave(&table->lock, flags);

	entry = (struct irte_ga *)table->table;
	entry = &entry[index];
	entry->lo.fields_remap.valid = 0;
	entry->hi.val = irte->hi.val;
	entry->lo.val = irte->lo.val;
	entry->lo.fields_remap.valid = 1;
	if (data)
		data->ref = entry;

	raw_spin_unlock_irqrestore(&table->lock, flags);

	iommu_flush_irt(iommu, devid);
	iommu_completion_wait(iommu);

	return 0;
}

static int modify_irte(u16 devid, int index, union irte *irte)
{
	struct irq_remap_table *table;
	struct amd_iommu *iommu;
	unsigned long flags;

	iommu = amd_iommu_rlookup_table[devid];
	if (iommu == NULL)
		return -EINVAL;

	table = get_irq_table(devid);
	if (!table)
		return -ENOMEM;

	raw_spin_lock_irqsave(&table->lock, flags);
	table->table[index] = irte->val;
	raw_spin_unlock_irqrestore(&table->lock, flags);

	iommu_flush_irt(iommu, devid);
	iommu_completion_wait(iommu);

	return 0;
}

static void free_irte(u16 devid, int index)
{
	struct irq_remap_table *table;
	struct amd_iommu *iommu;
	unsigned long flags;

	iommu = amd_iommu_rlookup_table[devid];
	if (iommu == NULL)
		return;

	table = get_irq_table(devid);
	if (!table)
		return;

	raw_spin_lock_irqsave(&table->lock, flags);
	iommu->irte_ops->clear_allocated(table, index);
	raw_spin_unlock_irqrestore(&table->lock, flags);

	iommu_flush_irt(iommu, devid);
	iommu_completion_wait(iommu);
}

static void irte_prepare(void *entry,
			 u32 delivery_mode, u32 dest_mode,
			 u8 vector, u32 dest_apicid, int devid)
{
	union irte *irte = (union irte *) entry;

	irte->val                = 0;
	irte->fields.vector      = vector;
	irte->fields.int_type    = delivery_mode;
	irte->fields.destination = dest_apicid;
	irte->fields.dm          = dest_mode;
	irte->fields.valid       = 1;
}

static void irte_ga_prepare(void *entry,
			    u32 delivery_mode, u32 dest_mode,
			    u8 vector, u32 dest_apicid, int devid)
{
	struct irte_ga *irte = (struct irte_ga *) entry;

	irte->lo.val                      = 0;
	irte->hi.val                      = 0;
	irte->lo.fields_remap.int_type    = delivery_mode;
	irte->lo.fields_remap.dm          = dest_mode;
	irte->hi.fields.vector            = vector;
	irte->lo.fields_remap.destination = APICID_TO_IRTE_DEST_LO(dest_apicid);
	irte->hi.fields.destination       = APICID_TO_IRTE_DEST_HI(dest_apicid);
	irte->lo.fields_remap.valid       = 1;
}

static void irte_activate(void *entry, u16 devid, u16 index)
{
	union irte *irte = (union irte *) entry;

	irte->fields.valid = 1;
	modify_irte(devid, index, irte);
}

static void irte_ga_activate(void *entry, u16 devid, u16 index)
{
	struct irte_ga *irte = (struct irte_ga *) entry;

	irte->lo.fields_remap.valid = 1;
	modify_irte_ga(devid, index, irte, NULL);
}

static void irte_deactivate(void *entry, u16 devid, u16 index)
{
	union irte *irte = (union irte *) entry;

	irte->fields.valid = 0;
	modify_irte(devid, index, irte);
}

static void irte_ga_deactivate(void *entry, u16 devid, u16 index)
{
	struct irte_ga *irte = (struct irte_ga *) entry;

	irte->lo.fields_remap.valid = 0;
	modify_irte_ga(devid, index, irte, NULL);
}

static void irte_set_affinity(void *entry, u16 devid, u16 index,
			      u8 vector, u32 dest_apicid)
{
	union irte *irte = (union irte *) entry;

	irte->fields.vector = vector;
	irte->fields.destination = dest_apicid;
	modify_irte(devid, index, irte);
}

static void irte_ga_set_affinity(void *entry, u16 devid, u16 index,
				 u8 vector, u32 dest_apicid)
{
	struct irte_ga *irte = (struct irte_ga *) entry;

	if (!irte->lo.fields_remap.guest_mode) {
		irte->hi.fields.vector = vector;
		irte->lo.fields_remap.destination =
					APICID_TO_IRTE_DEST_LO(dest_apicid);
		irte->hi.fields.destination =
					APICID_TO_IRTE_DEST_HI(dest_apicid);
		modify_irte_ga(devid, index, irte, NULL);
	}
}

#define IRTE_ALLOCATED (~1U)
static void irte_set_allocated(struct irq_remap_table *table, int index)
{
	table->table[index] = IRTE_ALLOCATED;
}

static void irte_ga_set_allocated(struct irq_remap_table *table, int index)
{
	struct irte_ga *ptr = (struct irte_ga *)table->table;
	struct irte_ga *irte = &ptr[index];

	memset(&irte->lo.val, 0, sizeof(u64));
	memset(&irte->hi.val, 0, sizeof(u64));
	irte->hi.fields.vector = 0xff;
}

static bool irte_is_allocated(struct irq_remap_table *table, int index)
{
	union irte *ptr = (union irte *)table->table;
	union irte *irte = &ptr[index];

	return irte->val != 0;
}

static bool irte_ga_is_allocated(struct irq_remap_table *table, int index)
{
	struct irte_ga *ptr = (struct irte_ga *)table->table;
	struct irte_ga *irte = &ptr[index];

	return irte->hi.fields.vector != 0;
}

static void irte_clear_allocated(struct irq_remap_table *table, int index)
{
	table->table[index] = 0;
}

static void irte_ga_clear_allocated(struct irq_remap_table *table, int index)
{
	struct irte_ga *ptr = (struct irte_ga *)table->table;
	struct irte_ga *irte = &ptr[index];

	memset(&irte->lo.val, 0, sizeof(u64));
	memset(&irte->hi.val, 0, sizeof(u64));
}

static int get_devid(struct irq_alloc_info *info)
{
	int devid = -1;

	switch (info->type) {
	case X86_IRQ_ALLOC_TYPE_IOAPIC:
		devid     = get_ioapic_devid(info->ioapic_id);
		break;
	case X86_IRQ_ALLOC_TYPE_HPET:
		devid     = get_hpet_devid(info->hpet_id);
		break;
	case X86_IRQ_ALLOC_TYPE_MSI:
	case X86_IRQ_ALLOC_TYPE_MSIX:
		devid = get_device_id(&info->msi_dev->dev);
		break;
	default:
		BUG_ON(1);
		break;
	}

	return devid;
}

static struct irq_domain *get_ir_irq_domain(struct irq_alloc_info *info)
{
	struct amd_iommu *iommu;
	int devid;

	if (!info)
		return NULL;

	devid = get_devid(info);
	if (devid >= 0) {
		iommu = amd_iommu_rlookup_table[devid];
		if (iommu)
			return iommu->ir_domain;
	}

	return NULL;
}

static struct irq_domain *get_irq_domain(struct irq_alloc_info *info)
{
	struct amd_iommu *iommu;
	int devid;

	if (!info)
		return NULL;

	switch (info->type) {
	case X86_IRQ_ALLOC_TYPE_MSI:
	case X86_IRQ_ALLOC_TYPE_MSIX:
		devid = get_device_id(&info->msi_dev->dev);
		if (devid < 0)
			return NULL;

		iommu = amd_iommu_rlookup_table[devid];
		if (iommu)
			return iommu->msi_domain;
		break;
	default:
		break;
	}

	return NULL;
}

struct irq_remap_ops amd_iommu_irq_ops = {
	.prepare		= amd_iommu_prepare,
	.enable			= amd_iommu_enable,
	.disable		= amd_iommu_disable,
	.reenable		= amd_iommu_reenable,
	.enable_faulting	= amd_iommu_enable_faulting,
	.get_ir_irq_domain	= get_ir_irq_domain,
	.get_irq_domain		= get_irq_domain,
};

static void irq_remapping_prepare_irte(struct amd_ir_data *data,
				       struct irq_cfg *irq_cfg,
				       struct irq_alloc_info *info,
				       int devid, int index, int sub_handle)
{
	struct irq_2_irte *irte_info = &data->irq_2_irte;
	struct msi_msg *msg = &data->msi_entry;
	struct IO_APIC_route_entry *entry;
	struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];

	if (!iommu)
		return;

	data->irq_2_irte.devid = devid;
	data->irq_2_irte.index = index + sub_handle;
	iommu->irte_ops->prepare(data->entry, apic->irq_delivery_mode,
				 apic->irq_dest_mode, irq_cfg->vector,
				 irq_cfg->dest_apicid, devid);

	switch (info->type) {
	case X86_IRQ_ALLOC_TYPE_IOAPIC:
		/* Setup IOAPIC entry */
		entry = info->ioapic_entry;
		info->ioapic_entry = NULL;
		memset(entry, 0, sizeof(*entry));
		entry->vector        = index;
		entry->mask          = 0;
		entry->trigger       = info->ioapic_trigger;
		entry->polarity      = info->ioapic_polarity;
		/* Mask level triggered irqs. */
		if (info->ioapic_trigger)
			entry->mask = 1;
		break;

	case X86_IRQ_ALLOC_TYPE_HPET:
	case X86_IRQ_ALLOC_TYPE_MSI:
	case X86_IRQ_ALLOC_TYPE_MSIX:
		msg->address_hi = MSI_ADDR_BASE_HI;
		msg->address_lo = MSI_ADDR_BASE_LO;
		msg->data = irte_info->index;
		break;

	default:
		BUG_ON(1);
		break;
	}
}

struct amd_irte_ops irte_32_ops = {
	.prepare = irte_prepare,
	.activate = irte_activate,
	.deactivate = irte_deactivate,
	.set_affinity = irte_set_affinity,
	.set_allocated = irte_set_allocated,
	.is_allocated = irte_is_allocated,
	.clear_allocated = irte_clear_allocated,
};

struct amd_irte_ops irte_128_ops = {
	.prepare = irte_ga_prepare,
	.activate = irte_ga_activate,
	.deactivate = irte_ga_deactivate,
	.set_affinity = irte_ga_set_affinity,
	.set_allocated = irte_ga_set_allocated,
	.is_allocated = irte_ga_is_allocated,
	.clear_allocated = irte_ga_clear_allocated,
};

static int irq_remapping_alloc(struct irq_domain *domain, unsigned int virq,
			       unsigned int nr_irqs, void *arg)
{
	struct irq_alloc_info *info = arg;
	struct irq_data *irq_data;
	struct amd_ir_data *data = NULL;
	struct irq_cfg *cfg;
	int i, ret, devid;
	int index;

	if (!info)
		return -EINVAL;
	if (nr_irqs > 1 && info->type != X86_IRQ_ALLOC_TYPE_MSI &&
	    info->type != X86_IRQ_ALLOC_TYPE_MSIX)
		return -EINVAL;

	/*
	 * With IRQ remapping enabled, don't need contiguous CPU vectors
	 * to support multiple MSI interrupts.
	 */
	if (info->type == X86_IRQ_ALLOC_TYPE_MSI)
		info->flags &= ~X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;

	devid = get_devid(info);
	if (devid < 0)
		return -EINVAL;

	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
	if (ret < 0)
		return ret;

	if (info->type == X86_IRQ_ALLOC_TYPE_IOAPIC) {
		struct irq_remap_table *table;
		struct amd_iommu *iommu;

		table = alloc_irq_table(devid, NULL);
		if (table) {
			if (!table->min_index) {
				/*
				 * Keep the first 32 indexes free for IOAPIC
				 * interrupts.
				 */
				table->min_index = 32;
				iommu = amd_iommu_rlookup_table[devid];
				for (i = 0; i < 32; ++i)
					iommu->irte_ops->set_allocated(table, i);
			}
			WARN_ON(table->min_index != 32);
			index = info->ioapic_pin;
		} else {
			index = -ENOMEM;
		}
	} else if (info->type == X86_IRQ_ALLOC_TYPE_MSI ||
		   info->type == X86_IRQ_ALLOC_TYPE_MSIX) {
		bool align = (info->type == X86_IRQ_ALLOC_TYPE_MSI);

		index = alloc_irq_index(devid, nr_irqs, align, info->msi_dev);
	} else {
		index = alloc_irq_index(devid, nr_irqs, false, NULL);
	}

	if (index < 0) {
		pr_warn("Failed to allocate IRTE\n");
		ret = index;
		goto out_free_parent;
	}

	for (i = 0; i < nr_irqs; i++) {
		irq_data = irq_domain_get_irq_data(domain, virq + i);
		cfg = irqd_cfg(irq_data);
		if (!irq_data || !cfg) {
			ret = -EINVAL;
			goto out_free_data;
		}

		ret = -ENOMEM;
		data = kzalloc(sizeof(*data), GFP_KERNEL);
		if (!data)
			goto out_free_data;

		if (!AMD_IOMMU_GUEST_IR_GA(amd_iommu_guest_ir))
			data->entry = kzalloc(sizeof(union irte), GFP_KERNEL);
		else
			data->entry = kzalloc(sizeof(struct irte_ga),
						     GFP_KERNEL);
		if (!data->entry) {
			kfree(data);
			goto out_free_data;
		}

		irq_data->hwirq = (devid << 16) + i;
		irq_data->chip_data = data;
		irq_data->chip = &amd_ir_chip;
		irq_remapping_prepare_irte(data, cfg, info, devid, index, i);
		irq_set_status_flags(virq + i, IRQ_MOVE_PCNTXT);
	}

	return 0;

out_free_data:
	for (i--; i >= 0; i--) {
		irq_data = irq_domain_get_irq_data(domain, virq + i);
		if (irq_data)
			kfree(irq_data->chip_data);
	}
	for (i = 0; i < nr_irqs; i++)
		free_irte(devid, index + i);
out_free_parent:
	irq_domain_free_irqs_common(domain, virq, nr_irqs);
	return ret;
}

static void irq_remapping_free(struct irq_domain *domain, unsigned int virq,
			       unsigned int nr_irqs)
{
	struct irq_2_irte *irte_info;
	struct irq_data *irq_data;
	struct amd_ir_data *data;
	int i;

	for (i = 0; i < nr_irqs; i++) {
		irq_data = irq_domain_get_irq_data(domain, virq  + i);
		if (irq_data && irq_data->chip_data) {
			data = irq_data->chip_data;
			irte_info = &data->irq_2_irte;
			free_irte(irte_info->devid, irte_info->index);
			kfree(data->entry);
			kfree(data);
		}
	}
	irq_domain_free_irqs_common(domain, virq, nr_irqs);
}

static void amd_ir_update_irte(struct irq_data *irqd, struct amd_iommu *iommu,
			       struct amd_ir_data *ir_data,
			       struct irq_2_irte *irte_info,
			       struct irq_cfg *cfg);

static int irq_remapping_activate(struct irq_domain *domain,
				  struct irq_data *irq_data, bool reserve)
{
	struct amd_ir_data *data = irq_data->chip_data;
	struct irq_2_irte *irte_info = &data->irq_2_irte;
	struct amd_iommu *iommu = amd_iommu_rlookup_table[irte_info->devid];
	struct irq_cfg *cfg = irqd_cfg(irq_data);

	if (!iommu)
		return 0;

	iommu->irte_ops->activate(data->entry, irte_info->devid,
				  irte_info->index);
	amd_ir_update_irte(irq_data, iommu, data, irte_info, cfg);
	return 0;
}

static void irq_remapping_deactivate(struct irq_domain *domain,
				     struct irq_data *irq_data)
{
	struct amd_ir_data *data = irq_data->chip_data;
	struct irq_2_irte *irte_info = &data->irq_2_irte;
	struct amd_iommu *iommu = amd_iommu_rlookup_table[irte_info->devid];

	if (iommu)
		iommu->irte_ops->deactivate(data->entry, irte_info->devid,
					    irte_info->index);
}

static const struct irq_domain_ops amd_ir_domain_ops = {
	.alloc = irq_remapping_alloc,
	.free = irq_remapping_free,
	.activate = irq_remapping_activate,
	.deactivate = irq_remapping_deactivate,
};

int amd_iommu_activate_guest_mode(void *data)
{
	struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
	struct irte_ga *entry = (struct irte_ga *) ir_data->entry;

	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
	    !entry || entry->lo.fields_vapic.guest_mode)
		return 0;

	entry->lo.val = 0;
	entry->hi.val = 0;

	entry->lo.fields_vapic.guest_mode  = 1;
	entry->lo.fields_vapic.ga_log_intr = 1;
	entry->hi.fields.ga_root_ptr       = ir_data->ga_root_ptr;
	entry->hi.fields.vector            = ir_data->ga_vector;
	entry->lo.fields_vapic.ga_tag      = ir_data->ga_tag;

	return modify_irte_ga(ir_data->irq_2_irte.devid,
			      ir_data->irq_2_irte.index, entry, ir_data);
}
EXPORT_SYMBOL(amd_iommu_activate_guest_mode);

int amd_iommu_deactivate_guest_mode(void *data)
{
	struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
	struct irte_ga *entry = (struct irte_ga *) ir_data->entry;
	struct irq_cfg *cfg = ir_data->cfg;

	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
	    !entry || !entry->lo.fields_vapic.guest_mode)
		return 0;

	entry->lo.val = 0;
	entry->hi.val = 0;

	entry->lo.fields_remap.dm          = apic->irq_dest_mode;
	entry->lo.fields_remap.int_type    = apic->irq_delivery_mode;
	entry->hi.fields.vector            = cfg->vector;
	entry->lo.fields_remap.destination =
				APICID_TO_IRTE_DEST_LO(cfg->dest_apicid);
	entry->hi.fields.destination =
				APICID_TO_IRTE_DEST_HI(cfg->dest_apicid);

	return modify_irte_ga(ir_data->irq_2_irte.devid,
			      ir_data->irq_2_irte.index, entry, ir_data);
}
EXPORT_SYMBOL(amd_iommu_deactivate_guest_mode);

static int amd_ir_set_vcpu_affinity(struct irq_data *data, void *vcpu_info)
{
	int ret;
	struct amd_iommu *iommu;
	struct amd_iommu_pi_data *pi_data = vcpu_info;
	struct vcpu_data *vcpu_pi_info = pi_data->vcpu_data;
	struct amd_ir_data *ir_data = data->chip_data;
	struct irq_2_irte *irte_info = &ir_data->irq_2_irte;
	struct iommu_dev_data *dev_data = search_dev_data(irte_info->devid);

	/* Note:
	 * This device has never been set up for guest mode.
	 * we should not modify the IRTE
	 */
	if (!dev_data || !dev_data->use_vapic)
		return 0;

	ir_data->cfg = irqd_cfg(data);
	pi_data->ir_data = ir_data;

	/* Note:
	 * SVM tries to set up for VAPIC mode, but we are in
	 * legacy mode. So, we force legacy mode instead.
	 */
	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir)) {
		pr_debug("%s: Fall back to using intr legacy remap\n",
			 __func__);
		pi_data->is_guest_mode = false;
	}

	iommu = amd_iommu_rlookup_table[irte_info->devid];
	if (iommu == NULL)
		return -EINVAL;

	pi_data->prev_ga_tag = ir_data->cached_ga_tag;
	if (pi_data->is_guest_mode) {
		ir_data->ga_root_ptr = (pi_data->base >> 12);
		ir_data->ga_vector = vcpu_pi_info->vector;
		ir_data->ga_tag = pi_data->ga_tag;
		ret = amd_iommu_activate_guest_mode(ir_data);
		if (!ret)
			ir_data->cached_ga_tag = pi_data->ga_tag;
	} else {
		ret = amd_iommu_deactivate_guest_mode(ir_data);

		/*
		 * This communicates the ga_tag back to the caller
		 * so that it can do all the necessary clean up.
		 */
		if (!ret)
			ir_data->cached_ga_tag = 0;
	}

	return ret;
}


static void amd_ir_update_irte(struct irq_data *irqd, struct amd_iommu *iommu,
			       struct amd_ir_data *ir_data,
			       struct irq_2_irte *irte_info,
			       struct irq_cfg *cfg)
{

	/*
	 * Atomically updates the IRTE with the new destination, vector
	 * and flushes the interrupt entry cache.
	 */
	iommu->irte_ops->set_affinity(ir_data->entry, irte_info->devid,
				      irte_info->index, cfg->vector,
				      cfg->dest_apicid);
}

static int amd_ir_set_affinity(struct irq_data *data,
			       const struct cpumask *mask, bool force)
{
	struct amd_ir_data *ir_data = data->chip_data;
	struct irq_2_irte *irte_info = &ir_data->irq_2_irte;
	struct irq_cfg *cfg = irqd_cfg(data);
	struct irq_data *parent = data->parent_data;
	struct amd_iommu *iommu = amd_iommu_rlookup_table[irte_info->devid];
	int ret;

	if (!iommu)
		return -ENODEV;

	ret = parent->chip->irq_set_affinity(parent, mask, force);
	if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
		return ret;

	amd_ir_update_irte(data, iommu, ir_data, irte_info, cfg);
	/*
	 * After this point, all the interrupts will start arriving
	 * at the new destination. So, time to cleanup the previous
	 * vector allocation.
	 */
	send_cleanup_vector(cfg);

	return IRQ_SET_MASK_OK_DONE;
}

static void ir_compose_msi_msg(struct irq_data *irq_data, struct msi_msg *msg)
{
	struct amd_ir_data *ir_data = irq_data->chip_data;

	*msg = ir_data->msi_entry;
}

static struct irq_chip amd_ir_chip = {
	.name			= "AMD-IR",
	.irq_ack		= apic_ack_irq,
	.irq_set_affinity	= amd_ir_set_affinity,
	.irq_set_vcpu_affinity	= amd_ir_set_vcpu_affinity,
	.irq_compose_msi_msg	= ir_compose_msi_msg,
};

int amd_iommu_create_irq_domain(struct amd_iommu *iommu)
{
	struct fwnode_handle *fn;

	fn = irq_domain_alloc_named_id_fwnode("AMD-IR", iommu->index);
	if (!fn)
		return -ENOMEM;
	iommu->ir_domain = irq_domain_create_tree(fn, &amd_ir_domain_ops, iommu);
	if (!iommu->ir_domain) {
		irq_domain_free_fwnode(fn);
		return -ENOMEM;
	}

	iommu->ir_domain->parent = arch_get_ir_parent_domain();
	iommu->msi_domain = arch_create_remap_msi_irq_domain(iommu->ir_domain,
							     "AMD-IR-MSI",
							     iommu->index);
	return 0;
}

int amd_iommu_update_ga(int cpu, bool is_run, void *data)
{
	unsigned long flags;
	struct amd_iommu *iommu;
	struct irq_remap_table *table;
	struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
	int devid = ir_data->irq_2_irte.devid;
	struct irte_ga *entry = (struct irte_ga *) ir_data->entry;
	struct irte_ga *ref = (struct irte_ga *) ir_data->ref;

	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
	    !ref || !entry || !entry->lo.fields_vapic.guest_mode)
		return 0;

	iommu = amd_iommu_rlookup_table[devid];
	if (!iommu)
		return -ENODEV;

	table = get_irq_table(devid);
	if (!table)
		return -ENODEV;

	raw_spin_lock_irqsave(&table->lock, flags);

	if (ref->lo.fields_vapic.guest_mode) {
		if (cpu >= 0) {
			ref->lo.fields_vapic.destination =
						APICID_TO_IRTE_DEST_LO(cpu);
			ref->hi.fields.destination =
						APICID_TO_IRTE_DEST_HI(cpu);
		}
		ref->lo.fields_vapic.is_run = is_run;
		barrier();
	}

	raw_spin_unlock_irqrestore(&table->lock, flags);

	iommu_flush_irt(iommu, devid);
	iommu_completion_wait(iommu);
	return 0;
}
EXPORT_SYMBOL(amd_iommu_update_ga);
#endif