linux/drivers/iommu/iommufd/device.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
 */
#include <linux/iommufd.h>
#include <linux/slab.h>
#include <linux/iommu.h>
#include <uapi/linux/iommufd.h>
#include "../iommu-priv.h"

#include "io_pagetable.h"
#include "iommufd_private.h"

static bool allow_unsafe_interrupts;
module_param(allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC();

static void iommufd_group_release(struct kref *kref)
{}

static void iommufd_put_group(struct iommufd_group *group)
{}

static bool iommufd_group_try_get(struct iommufd_group *igroup,
				  struct iommu_group *group)
{}

/*
 * iommufd needs to store some more data for each iommu_group, we keep a
 * parallel xarray indexed by iommu_group id to hold this instead of putting it
 * in the core structure. To keep things simple the iommufd_group memory is
 * unique within the iommufd_ctx. This makes it easy to check there are no
 * memory leaks.
 */
static struct iommufd_group *iommufd_get_group(struct iommufd_ctx *ictx,
					       struct device *dev)
{}

void iommufd_device_destroy(struct iommufd_object *obj)
{}

/**
 * iommufd_device_bind - Bind a physical device to an iommu fd
 * @ictx: iommufd file descriptor
 * @dev: Pointer to a physical device struct
 * @id: Output ID number to return to userspace for this device
 *
 * A successful bind establishes an ownership over the device and returns
 * struct iommufd_device pointer, otherwise returns error pointer.
 *
 * A driver using this API must set driver_managed_dma and must not touch
 * the device until this routine succeeds and establishes ownership.
 *
 * Binding a PCI device places the entire RID under iommufd control.
 *
 * The caller must undo this with iommufd_device_unbind()
 */
struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
					   struct device *dev, u32 *id)
{}
EXPORT_SYMBOL_NS_GPL();

/**
 * iommufd_ctx_has_group - True if any device within the group is bound
 *                         to the ictx
 * @ictx: iommufd file descriptor
 * @group: Pointer to a physical iommu_group struct
 *
 * True if any device within the group has been bound to this ictx, ex. via
 * iommufd_device_bind(), therefore implying ictx ownership of the group.
 */
bool iommufd_ctx_has_group(struct iommufd_ctx *ictx, struct iommu_group *group)
{}
EXPORT_SYMBOL_NS_GPL();

/**
 * iommufd_device_unbind - Undo iommufd_device_bind()
 * @idev: Device returned by iommufd_device_bind()
 *
 * Release the device from iommufd control. The DMA ownership will return back
 * to unowned with DMA controlled by the DMA API. This invalidates the
 * iommufd_device pointer, other APIs that consume it must not be called
 * concurrently.
 */
void iommufd_device_unbind(struct iommufd_device *idev)
{}
EXPORT_SYMBOL_NS_GPL();

struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev)
{}
EXPORT_SYMBOL_NS_GPL();

u32 iommufd_device_to_id(struct iommufd_device *idev)
{}
EXPORT_SYMBOL_NS_GPL();

static int iommufd_group_setup_msi(struct iommufd_group *igroup,
				   struct iommufd_hwpt_paging *hwpt_paging)
{}

static int iommufd_hwpt_paging_attach(struct iommufd_hwpt_paging *hwpt_paging,
				      struct iommufd_device *idev)
{}

int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
				struct iommufd_device *idev)
{}

struct iommufd_hw_pagetable *
iommufd_hw_pagetable_detach(struct iommufd_device *idev)
{}

static struct iommufd_hw_pagetable *
iommufd_device_do_attach(struct iommufd_device *idev,
			 struct iommufd_hw_pagetable *hwpt)
{}

static void
iommufd_group_remove_reserved_iova(struct iommufd_group *igroup,
				   struct iommufd_hwpt_paging *hwpt_paging)
{}

static int
iommufd_group_do_replace_paging(struct iommufd_group *igroup,
				struct iommufd_hwpt_paging *hwpt_paging)
{}

static struct iommufd_hw_pagetable *
iommufd_device_do_replace(struct iommufd_device *idev,
			  struct iommufd_hw_pagetable *hwpt)
{}

attach_fn;

/*
 * When automatically managing the domains we search for a compatible domain in
 * the iopt and if one is found use it, otherwise create a new domain.
 * Automatic domain selection will never pick a manually created domain.
 */
static struct iommufd_hw_pagetable *
iommufd_device_auto_get_domain(struct iommufd_device *idev,
			       struct iommufd_ioas *ioas, u32 *pt_id,
			       attach_fn do_attach)
{}

static int iommufd_device_change_pt(struct iommufd_device *idev, u32 *pt_id,
				    attach_fn do_attach)
{}

/**
 * iommufd_device_attach - Connect a device to an iommu_domain
 * @idev: device to attach
 * @pt_id: Input a IOMMUFD_OBJ_IOAS, or IOMMUFD_OBJ_HWPT_PAGING
 *         Output the IOMMUFD_OBJ_HWPT_PAGING ID
 *
 * This connects the device to an iommu_domain, either automatically or manually
 * selected. Once this completes the device could do DMA.
 *
 * The caller should return the resulting pt_id back to userspace.
 * This function is undone by calling iommufd_device_detach().
 */
int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id)
{}
EXPORT_SYMBOL_NS_GPL();

/**
 * iommufd_device_replace - Change the device's iommu_domain
 * @idev: device to change
 * @pt_id: Input a IOMMUFD_OBJ_IOAS, or IOMMUFD_OBJ_HWPT_PAGING
 *         Output the IOMMUFD_OBJ_HWPT_PAGING ID
 *
 * This is the same as::
 *
 *   iommufd_device_detach();
 *   iommufd_device_attach();
 *
 * If it fails then no change is made to the attachment. The iommu driver may
 * implement this so there is no disruption in translation. This can only be
 * called if iommufd_device_attach() has already succeeded.
 */
int iommufd_device_replace(struct iommufd_device *idev, u32 *pt_id)
{}
EXPORT_SYMBOL_NS_GPL();

/**
 * iommufd_device_detach - Disconnect a device to an iommu_domain
 * @idev: device to detach
 *
 * Undo iommufd_device_attach(). This disconnects the idev from the previously
 * attached pt_id. The device returns back to a blocked DMA translation.
 */
void iommufd_device_detach(struct iommufd_device *idev)
{}
EXPORT_SYMBOL_NS_GPL();

/*
 * On success, it will refcount_inc() at a valid new_ioas and refcount_dec() at
 * a valid cur_ioas (access->ioas). A caller passing in a valid new_ioas should
 * call iommufd_put_object() if it does an iommufd_get_object() for a new_ioas.
 */
static int iommufd_access_change_ioas(struct iommufd_access *access,
				      struct iommufd_ioas *new_ioas)
{}

static int iommufd_access_change_ioas_id(struct iommufd_access *access, u32 id)
{}

void iommufd_access_destroy_object(struct iommufd_object *obj)
{}

/**
 * iommufd_access_create - Create an iommufd_access
 * @ictx: iommufd file descriptor
 * @ops: Driver's ops to associate with the access
 * @data: Opaque data to pass into ops functions
 * @id: Output ID number to return to userspace for this access
 *
 * An iommufd_access allows a driver to read/write to the IOAS without using
 * DMA. The underlying CPU memory can be accessed using the
 * iommufd_access_pin_pages() or iommufd_access_rw() functions.
 *
 * The provided ops are required to use iommufd_access_pin_pages().
 */
struct iommufd_access *
iommufd_access_create(struct iommufd_ctx *ictx,
		      const struct iommufd_access_ops *ops, void *data, u32 *id)
{}
EXPORT_SYMBOL_NS_GPL();

/**
 * iommufd_access_destroy - Destroy an iommufd_access
 * @access: The access to destroy
 *
 * The caller must stop using the access before destroying it.
 */
void iommufd_access_destroy(struct iommufd_access *access)
{}
EXPORT_SYMBOL_NS_GPL();

void iommufd_access_detach(struct iommufd_access *access)
{}
EXPORT_SYMBOL_NS_GPL();

int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id)
{}
EXPORT_SYMBOL_NS_GPL();

int iommufd_access_replace(struct iommufd_access *access, u32 ioas_id)
{}
EXPORT_SYMBOL_NS_GPL();

/**
 * iommufd_access_notify_unmap - Notify users of an iopt to stop using it
 * @iopt: iopt to work on
 * @iova: Starting iova in the iopt
 * @length: Number of bytes
 *
 * After this function returns there should be no users attached to the pages
 * linked to this iopt that intersect with iova,length. Anyone that has attached
 * a user through iopt_access_pages() needs to detach it through
 * iommufd_access_unpin_pages() before this function returns.
 *
 * iommufd_access_destroy() will wait for any outstanding unmap callback to
 * complete. Once iommufd_access_destroy() no unmap ops are running or will
 * run in the future. Due to this a driver must not create locking that prevents
 * unmap to complete while iommufd_access_destroy() is running.
 */
void iommufd_access_notify_unmap(struct io_pagetable *iopt, unsigned long iova,
				 unsigned long length)
{}

/**
 * iommufd_access_unpin_pages() - Undo iommufd_access_pin_pages
 * @access: IOAS access to act on
 * @iova: Starting IOVA
 * @length: Number of bytes to access
 *
 * Return the struct page's. The caller must stop accessing them before calling
 * this. The iova/length must exactly match the one provided to access_pages.
 */
void iommufd_access_unpin_pages(struct iommufd_access *access,
				unsigned long iova, unsigned long length)
{}
EXPORT_SYMBOL_NS_GPL();

static bool iopt_area_contig_is_aligned(struct iopt_area_contig_iter *iter)
{}

static bool check_area_prot(struct iopt_area *area, unsigned int flags)
{}

/**
 * iommufd_access_pin_pages() - Return a list of pages under the iova
 * @access: IOAS access to act on
 * @iova: Starting IOVA
 * @length: Number of bytes to access
 * @out_pages: Output page list
 * @flags: IOPMMUFD_ACCESS_RW_* flags
 *
 * Reads @length bytes starting at iova and returns the struct page * pointers.
 * These can be kmap'd by the caller for CPU access.
 *
 * The caller must perform iommufd_access_unpin_pages() when done to balance
 * this.
 *
 * This API always requires a page aligned iova. This happens naturally if the
 * ioas alignment is >= PAGE_SIZE and the iova is PAGE_SIZE aligned. However
 * smaller alignments have corner cases where this API can fail on otherwise
 * aligned iova.
 */
int iommufd_access_pin_pages(struct iommufd_access *access, unsigned long iova,
			     unsigned long length, struct page **out_pages,
			     unsigned int flags)
{}
EXPORT_SYMBOL_NS_GPL();

/**
 * iommufd_access_rw - Read or write data under the iova
 * @access: IOAS access to act on
 * @iova: Starting IOVA
 * @data: Kernel buffer to copy to/from
 * @length: Number of bytes to access
 * @flags: IOMMUFD_ACCESS_RW_* flags
 *
 * Copy kernel to/from data into the range given by IOVA/length. If flags
 * indicates IOMMUFD_ACCESS_RW_KTHREAD then a large copy can be optimized
 * by changing it into copy_to/from_user().
 */
int iommufd_access_rw(struct iommufd_access *access, unsigned long iova,
		      void *data, size_t length, unsigned int flags)
{}
EXPORT_SYMBOL_NS_GPL();

int iommufd_get_hw_info(struct iommufd_ucmd *ucmd)
{}