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iommu/vt-d: Replace intel SVM APIs with generic SVA APIs

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This patch is an initial step to replace Intel SVM code with the
following IOMMU SVA ops:
intel_svm_bind_mm() => iommu_sva_bind_device()
intel_svm_unbind_mm() => iommu_sva_unbind_device()
intel_svm_is_pasid_valid() => iommu_sva_get_pasid()

The features below will continue to work but are not included in this patch
in that they are handled mostly within the IOMMU subsystem.
- IO page fault
- mmu notifier

Consolidation of the above will come after merging generic IOMMU sva
code[1]. There should not be any changes needed for SVA users such as
accelerator device drivers during this time.

[1] http://jpbrucker.net/sva/

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200516062101.29541-12-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Jacob Pan
2020-05-16 14:20:54 +08:00
committed by Joerg Roedel
parent 76fdd6c595
commit 064a57d7dd
4 changed files with 78 additions and 141 deletions
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86
include/linux/intel-svm.h
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@@ -21,7 +21,6 @@ struct svm_dev_ops {
#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
@@ -57,89 +56,4 @@ struct svm_dev_ops {
*/
#define SVM_FLAG_GUEST_PASID (1<<3)
#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__ */