linux/drivers/iommu/iommu-sva.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Helpers for IOMMU drivers implementing SVA
 */
#include <linux/mmu_context.h>
#include <linux/mutex.h>
#include <linux/sched/mm.h>
#include <linux/iommu.h>

#include "iommu-priv.h"

static DEFINE_MUTEX(iommu_sva_lock);
static struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
						   struct mm_struct *mm);

/* Allocate a PASID for the mm within range (inclusive) */
static struct iommu_mm_data *iommu_alloc_mm_data(struct mm_struct *mm, struct device *dev)
{ … }

/**
 * iommu_sva_bind_device() - Bind a process address space to a device
 * @dev: the device
 * @mm: the mm to bind, caller must hold a reference to mm_users
 *
 * Create a bond between device and address space, allowing the device to
 * access the mm using the PASID returned by iommu_sva_get_pasid(). If a
 * bond already exists between @device and @mm, an additional internal
 * reference is taken. Caller must call iommu_sva_unbind_device()
 * to release each reference.
 *
 * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
 * initialize the required SVA features.
 *
 * On error, returns an ERR_PTR value.
 */
struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
 * @handle: the handle returned by iommu_sva_bind_device()
 *
 * Put reference to a bond between device and address space. The device should
 * not be issuing any more transaction for this PASID. All outstanding page
 * requests for this PASID must have been flushed to the IOMMU.
 */
void iommu_sva_unbind_device(struct iommu_sva *handle)
{ … }
EXPORT_SYMBOL_GPL(…);

u32 iommu_sva_get_pasid(struct iommu_sva *handle)
{ … }
EXPORT_SYMBOL_GPL(…);

void mm_pasid_drop(struct mm_struct *mm)
{ … }

/*
 * I/O page fault handler for SVA
 */
static enum iommu_page_response_code
iommu_sva_handle_mm(struct iommu_fault *fault, struct mm_struct *mm)
{ … }

static void iommu_sva_handle_iopf(struct work_struct *work)
{ … }

static int iommu_sva_iopf_handler(struct iopf_group *group)
{ … }

static struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
						   struct mm_struct *mm)
{ … }