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iommu/vt-d: Add callback to device driver on page faults 

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
hifive-unleashed-5.1
David Woodhouse 2015-10-13 17:18:10 +01:00
parent a222a7f0bb
commit 0204a49609
3 changed files with 46 additions and 4 deletions
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26
drivers/iommu/intel-svm.c
View File

@ -264,7 +264,7 @@ static const struct mmu_notifier_ops intel_mmuops = {
static DEFINE_MUTEX(pasid_mutex);
int intel_svm_bind_mm(struct device *dev, int *pasid)
int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops)
{
struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
struct intel_svm_dev *sdev;
@ -302,6 +302,10 @@ int intel_svm_bind_mm(struct device *dev, int *pasid)
list_for_each_entry(sdev, &svm->devs, list) {
if (dev == sdev->dev) {
if (sdev->ops != ops) {
ret = -EBUSY;
goto out;
}
sdev->users++;
goto success;
}
@ -327,6 +331,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid)
}
/* Finish the setup now we know we're keeping it */
sdev->users = 1;
sdev->ops = ops;
init_rcu_head(&sdev->rcu);
if (!svm) {
@ -456,6 +461,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
while (head != tail) {
struct intel_svm_dev *sdev;
struct vm_area_struct *vma;
struct page_req_dsc *req;
struct qi_desc resp;
@ -507,6 +513,24 @@ static irqreturn_t prq_event_thread(int irq, void *d)
up_read(&svm->mm->mmap_sem);
bad_req:
/* Accounting for major/minor faults? */
rcu_read_lock();
list_for_each_entry_rcu(sdev, &svm->devs, list) {
if (sdev->sid == PCI_DEVID(req->bus, req->devfn));
break;
}
/* Other devices can go away, but the drivers are not permitted
* to unbind while any page faults might be in flight. So it's
* OK to drop the 'lock' here now we have it. */
rcu_read_unlock();
if (WARN_ON(&sdev->list == &svm->devs))
sdev = NULL;
if (sdev && sdev->ops && sdev->ops->fault_cb) {
int rwxp = (req->rd_req << 3) | (req->wr_req << 2) |
(req->wr_req << 1) | (req->exe_req);
sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr, req->private, rwxp, result);
}
if (req->lpig) {
/* Page Group Response */

3
include/linux/intel-iommu.h
View File

@ -472,10 +472,13 @@ extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu);
extern int intel_svm_enable_prq(struct intel_iommu *iommu);
extern int intel_svm_finish_prq(struct intel_iommu *iommu);
struct svm_dev_ops;
struct intel_svm_dev {
struct list_head list;
struct rcu_head rcu;
struct device *dev;
struct svm_dev_ops *ops;
int users;
u16 did;
u16 dev_iotlb:1;

21
include/linux/intel-svm.h
View File

@ -20,10 +20,23 @@
struct device;
struct svm_dev_ops {
void (*fault_cb)(struct device *dev, int pasid, u64 address,
u32 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)
/**
* intel_svm_bind_mm() - Bind the current process to a PASID
* @dev: Device to be granted acccess
* @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
@ -45,7 +58,8 @@ struct device;
* 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);
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
@ -66,7 +80,8 @@ extern int intel_svm_unbind_mm(struct device *dev, int pasid);
#else /* CONFIG_INTEL_IOMMU_SVM */
static inline int intel_svm_bind_mm(struct device *dev, int *pasid)
static inline int intel_svm_bind_mm(struct device *dev, int *pasid,
int flags, struct svm_dev_ops *ops)
{
return -ENOSYS;
}
@ -77,6 +92,6 @@ static inline int intel_svm_unbind_mm(struct device *dev, int pasid)
}
#endif /* CONFIG_INTEL_IOMMU_SVM */
#define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL))
#define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL, 0, NULL))
#endif /* __INTEL_SVM_H__ */