134 строки
4.6 KiB
C
134 строки
4.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copyright © 2015 Intel Corporation.
|
|
*
|
|
* Authors: David Woodhouse <David.Woodhouse@intel.com>
|
|
*/
|
|
|
|
#ifndef __INTEL_SVM_H__
|
|
#define __INTEL_SVM_H__
|
|
|
|
struct device;
|
|
|
|
struct svm_dev_ops {
|
|
void (*fault_cb)(struct device *dev, int pasid, u64 address,
|
|
void *private, int rwxp, int response);
|
|
};
|
|
|
|
/* Values for rxwp in fault_cb callback */
|
|
#define SVM_REQ_READ (1<<3)
|
|
#define SVM_REQ_WRITE (1<<2)
|
|
#define SVM_REQ_EXEC (1<<1)
|
|
#define SVM_REQ_PRIV (1<<0)
|
|
|
|
|
|
/*
|
|
* The SVM_FLAG_PRIVATE_PASID flag requests a PASID which is *not* the "main"
|
|
* PASID for the current process. Even if a PASID already exists, a new one
|
|
* will be allocated. And the PASID allocated with SVM_FLAG_PRIVATE_PASID
|
|
* will not be given to subsequent callers. This facility allows a driver to
|
|
* disambiguate between multiple device contexts which access the same MM,
|
|
* if there is no other way to do so. It should be used sparingly, if at all.
|
|
*/
|
|
#define SVM_FLAG_PRIVATE_PASID (1<<0)
|
|
|
|
/*
|
|
* The SVM_FLAG_SUPERVISOR_MODE flag requests a PASID which can be used only
|
|
* for access to kernel addresses. No IOTLB flushes are automatically done
|
|
* for kernel mappings; it is valid only for access to the kernel's static
|
|
* 1:1 mapping of physical memory — not to vmalloc or even module mappings.
|
|
* A future API addition may permit the use of such ranges, by means of an
|
|
* explicit IOTLB flush call (akin to the DMA API's unmap method).
|
|
*
|
|
* It is unlikely that we will ever hook into flush_tlb_kernel_range() to
|
|
* do such IOTLB flushes automatically.
|
|
*/
|
|
#define SVM_FLAG_SUPERVISOR_MODE (1<<1)
|
|
|
|
#ifdef CONFIG_INTEL_IOMMU_SVM
|
|
|
|
/**
|
|
* intel_svm_bind_mm() - Bind the current process to a PASID
|
|
* @dev: Device to be granted access
|
|
* @pasid: Address for allocated PASID
|
|
* @flags: Flags. Later for requesting supervisor mode, etc.
|
|
* @ops: Callbacks to device driver
|
|
*
|
|
* This function attempts to enable PASID support for the given device.
|
|
* If the @pasid argument is non-%NULL, a PASID is allocated for access
|
|
* to the MM of the current process.
|
|
*
|
|
* By using a %NULL value for the @pasid argument, this function can
|
|
* be used to simply validate that PASID support is available for the
|
|
* given device — i.e. that it is behind an IOMMU which has the
|
|
* requisite support, and is enabled.
|
|
*
|
|
* Page faults are handled transparently by the IOMMU code, and there
|
|
* should be no need for the device driver to be involved. If a page
|
|
* fault cannot be handled (i.e. is an invalid address rather than
|
|
* just needs paging in), then the page request will be completed by
|
|
* the core IOMMU code with appropriate status, and the device itself
|
|
* can then report the resulting fault to its driver via whatever
|
|
* mechanism is appropriate.
|
|
*
|
|
* Multiple calls from the same process may result in the same PASID
|
|
* being re-used. A reference count is kept.
|
|
*/
|
|
extern int intel_svm_bind_mm(struct device *dev, int *pasid, int flags,
|
|
struct svm_dev_ops *ops);
|
|
|
|
/**
|
|
* intel_svm_unbind_mm() - Unbind a specified PASID
|
|
* @dev: Device for which PASID was allocated
|
|
* @pasid: PASID value to be unbound
|
|
*
|
|
* This function allows a PASID to be retired when the device no
|
|
* longer requires access to the address space of a given process.
|
|
*
|
|
* If the use count for the PASID in question reaches zero, the
|
|
* PASID is revoked and may no longer be used by hardware.
|
|
*
|
|
* Device drivers are required to ensure that no access (including
|
|
* page requests) is currently outstanding for the PASID in question,
|
|
* before calling this function.
|
|
*/
|
|
extern int intel_svm_unbind_mm(struct device *dev, int pasid);
|
|
|
|
/**
|
|
* intel_svm_is_pasid_valid() - check if pasid is valid
|
|
* @dev: Device for which PASID was allocated
|
|
* @pasid: PASID value to be checked
|
|
*
|
|
* This function checks if the specified pasid is still valid. A
|
|
* valid pasid means the backing mm is still having a valid user.
|
|
* For kernel callers init_mm is always valid. for other mm, if mm->mm_users
|
|
* is non-zero, it is valid.
|
|
*
|
|
* returns -EINVAL if invalid pasid, 0 if pasid ref count is invalid
|
|
* 1 if pasid is valid.
|
|
*/
|
|
extern int intel_svm_is_pasid_valid(struct device *dev, int pasid);
|
|
|
|
#else /* CONFIG_INTEL_IOMMU_SVM */
|
|
|
|
static inline int intel_svm_bind_mm(struct device *dev, int *pasid,
|
|
int flags, struct svm_dev_ops *ops)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline int intel_svm_unbind_mm(struct device *dev, int pasid)
|
|
{
|
|
BUG();
|
|
}
|
|
|
|
static inline int intel_svm_is_pasid_valid(struct device *dev, int pasid)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif /* CONFIG_INTEL_IOMMU_SVM */
|
|
|
|
#define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL, 0, NULL))
|
|
|
|
#endif /* __INTEL_SVM_H__ */
|