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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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/iommu/intel-iommu.c
View File

@ -6071,6 +6071,9 @@ const struct iommu_ops intel_iommu_ops = {
.cache_invalidate = intel_iommu_sva_invalidate,
.sva_bind_gpasid = intel_svm_bind_gpasid,
.sva_unbind_gpasid = intel_svm_unbind_gpasid,
.sva_bind = intel_svm_bind,
.sva_unbind = intel_svm_unbind,
.sva_get_pasid = intel_svm_get_pasid,
#endif
};

124
drivers/iommu/intel-svm.c
View File

@ -426,13 +426,15 @@ out:
return ret;
}
int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops)
/* Caller must hold pasid_mutex, mm reference */
static int
intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *ops,
struct mm_struct *mm, struct intel_svm_dev **sd)
{
struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
struct device_domain_info *info;
struct intel_svm_dev *sdev;
struct intel_svm *svm = NULL;
struct mm_struct *mm = NULL;
int pasid_max;
int ret;
@ -449,16 +451,15 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
} else
pasid_max = 1 << 20;
/* Bind supervisor PASID shuld have mm = NULL */
if (flags & SVM_FLAG_SUPERVISOR_MODE) {
if (!ecap_srs(iommu->ecap))
if (!ecap_srs(iommu->ecap) || mm) {
pr_err("Supervisor PASID with user provided mm.\n");
return -EINVAL;
} else if (pasid) {
mm = get_task_mm(current);
BUG_ON(!mm);
}
}
mutex_lock(&pasid_mutex);
if (pasid && !(flags & SVM_FLAG_PRIVATE_PASID)) {
if (!(flags & SVM_FLAG_PRIVATE_PASID)) {
struct intel_svm *t;
list_for_each_entry(t, &global_svm_list, list) {
@ -496,9 +497,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
sdev->dev = dev;
ret = intel_iommu_enable_pasid(iommu, dev);
if (ret || !pasid) {
/* If they don't actually want to assign a PASID, this is
* just an enabling check/preparation. */
if (ret) {
kfree(sdev);
goto out;
}
@ -597,18 +596,17 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
}
}
list_add_rcu(&sdev->list, &svm->devs);
success:
*pasid = svm->pasid;
success:
sdev->pasid = svm->pasid;
sdev->sva.dev = dev;
if (sd)
*sd = sdev;
ret = 0;
out:
mutex_unlock(&pasid_mutex);
if (mm)
mmput(mm);
return ret;
}
EXPORT_SYMBOL_GPL(intel_svm_bind_mm);
/* Caller must hold pasid_mutex */
int intel_svm_unbind_mm(struct device *dev, int pasid)
{
struct intel_svm_dev *sdev;
@ -616,7 +614,6 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
struct intel_svm *svm;
int ret = -EINVAL;
mutex_lock(&pasid_mutex);
iommu = intel_svm_device_to_iommu(dev);
if (!iommu)
goto out;
@ -662,45 +659,9 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
break;
}
out:
mutex_unlock(&pasid_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(intel_svm_unbind_mm);
int intel_svm_is_pasid_valid(struct device *dev, int pasid)
{
struct intel_iommu *iommu;
struct intel_svm *svm;
int ret = -EINVAL;
mutex_lock(&pasid_mutex);
iommu = intel_svm_device_to_iommu(dev);
if (!iommu)
goto out;
svm = ioasid_find(NULL, pasid, NULL);
if (!svm)
goto out;
if (IS_ERR(svm)) {
ret = PTR_ERR(svm);
goto out;
}
/* init_mm is used in this case */
if (!svm->mm)
ret = 1;
else if (atomic_read(&svm->mm->mm_users) > 0)
ret = 1;
else
ret = 0;
out:
mutex_unlock(&pasid_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(intel_svm_is_pasid_valid);
/* Page request queue descriptor */
struct page_req_dsc {
@ -894,3 +855,56 @@ static irqreturn_t prq_event_thread(int irq, void *d)
return IRQ_RETVAL(handled);
}
#define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva)
struct iommu_sva *
intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
{
struct iommu_sva *sva = ERR_PTR(-EINVAL);
struct intel_svm_dev *sdev = NULL;
int flags = 0;
int ret;
/*
* TODO: Consolidate with generic iommu-sva bind after it is merged.
* It will require shared SVM data structures, i.e. combine io_mm
* and intel_svm etc.
*/
if (drvdata)
flags = *(int *)drvdata;
mutex_lock(&pasid_mutex);
ret = intel_svm_bind_mm(dev, flags, NULL, mm, &sdev);
if (ret)
sva = ERR_PTR(ret);
else if (sdev)
sva = &sdev->sva;
else
WARN(!sdev, "SVM bind succeeded with no sdev!\n");
mutex_unlock(&pasid_mutex);
return sva;
}
void intel_svm_unbind(struct iommu_sva *sva)
{
struct intel_svm_dev *sdev;
mutex_lock(&pasid_mutex);
sdev = to_intel_svm_dev(sva);
intel_svm_unbind_mm(sdev->dev, sdev->pasid);
mutex_unlock(&pasid_mutex);
}
int intel_svm_get_pasid(struct iommu_sva *sva)
{
struct intel_svm_dev *sdev;
int pasid;
mutex_lock(&pasid_mutex);
sdev = to_intel_svm_dev(sva);
pasid = sdev->pasid;
mutex_unlock(&pasid_mutex);
return pasid;
}

6
include/linux/intel-iommu.h
View File

@ -723,6 +723,10 @@ extern int intel_svm_finish_prq(struct intel_iommu *iommu);
int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
struct iommu_gpasid_bind_data *data);
int intel_svm_unbind_gpasid(struct device *dev, int pasid);
struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm,
void *drvdata);
void intel_svm_unbind(struct iommu_sva *handle);
int intel_svm_get_pasid(struct iommu_sva *handle);
struct svm_dev_ops;
struct intel_svm_dev {
@ -730,6 +734,8 @@ struct intel_svm_dev {
struct rcu_head rcu;
struct device *dev;
struct svm_dev_ops *ops;
struct iommu_sva sva;
int pasid;
int users;
u16 did;
u16 dev_iotlb:1;

86
include/linux/intel-svm.h
View File

@ -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__ */