Commit 66ac4db3 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel

iommu/vt-d: Add page request draining support

When a PASID is stopped or terminated, there can be pending PRQs
(requests that haven't received responses) in remapping hardware.
This adds the interface to drain page requests and call it when a
PASID is terminated.
Signed-off-by: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarLiu Yi L <yi.l.liu@intel.com>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200516062101.29541-16-baolu.lu@linux.intel.comSigned-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 37e91bd4
......@@ -23,6 +23,7 @@
#include "intel-pasid.h"
static irqreturn_t prq_event_thread(int irq, void *d);
static void intel_svm_drain_prq(struct device *dev, int pasid);
#define PRQ_ORDER 0
......@@ -66,6 +67,8 @@ int intel_svm_enable_prq(struct intel_iommu *iommu)
dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER);
init_completion(&iommu->prq_complete);
return 0;
}
......@@ -399,12 +402,8 @@ int intel_svm_unbind_gpasid(struct device *dev, int pasid)
list_del_rcu(&sdev->list);
intel_pasid_tear_down_entry(iommu, dev,
svm->pasid, false);
intel_svm_drain_prq(dev, svm->pasid);
intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
/* TODO: Drain in flight PRQ for the PASID since it
* may get reused soon, we don't want to
* confuse with its previous life.
* intel_svm_drain_prq(dev, pasid);
*/
kfree_rcu(sdev, rcu);
if (list_empty(&svm->devs)) {
......@@ -643,6 +642,7 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
* hard to be as defensive as we might like. */
intel_pasid_tear_down_entry(iommu, dev,
svm->pasid, false);
intel_svm_drain_prq(dev, svm->pasid);
intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
kfree_rcu(sdev, rcu);
......@@ -721,6 +721,93 @@ static bool is_canonical_address(u64 addr)
return (((saddr << shift) >> shift) == saddr);
}
/**
* intel_svm_drain_prq - Drain page requests and responses for a pasid
* @dev: target device
* @pasid: pasid for draining
*
* Drain all pending page requests and responses related to @pasid in both
* software and hardware. This is supposed to be called after the device
* driver has stopped DMA, the pasid entry has been cleared, and both IOTLB
* and DevTLB have been invalidated.
*
* It waits until all pending page requests for @pasid in the page fault
* queue are completed by the prq handling thread. Then follow the steps
* described in VT-d spec CH7.10 to drain all page requests and page
* responses pending in the hardware.
*/
static void intel_svm_drain_prq(struct device *dev, int pasid)
{
struct device_domain_info *info;
struct dmar_domain *domain;
struct intel_iommu *iommu;
struct qi_desc desc[3];
struct pci_dev *pdev;
int head, tail;
u16 sid, did;
int qdep;
info = get_domain_info(dev);
if (WARN_ON(!info || !dev_is_pci(dev)))
return;
if (!info->pri_enabled)
return;
iommu = info->iommu;
domain = info->domain;
pdev = to_pci_dev(dev);
sid = PCI_DEVID(info->bus, info->devfn);
did = domain->iommu_did[iommu->seq_id];
qdep = pci_ats_queue_depth(pdev);
/*
* Check and wait until all pending page requests in the queue are
* handled by the prq handling thread.
*/
prq_retry:
reinit_completion(&iommu->prq_complete);
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 page_req_dsc *req;
req = &iommu->prq[head / sizeof(*req)];
if (!req->pasid_present || req->pasid != pasid) {
head = (head + sizeof(*req)) & PRQ_RING_MASK;
continue;
}
wait_for_completion(&iommu->prq_complete);
goto prq_retry;
}
/*
* Perform steps described in VT-d spec CH7.10 to drain page
* requests and responses in hardware.
*/
memset(desc, 0, sizeof(desc));
desc[0].qw0 = QI_IWD_STATUS_DATA(QI_DONE) |
QI_IWD_FENCE |
QI_IWD_TYPE;
desc[1].qw0 = QI_EIOTLB_PASID(pasid) |
QI_EIOTLB_DID(did) |
QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) |
QI_EIOTLB_TYPE;
desc[2].qw0 = QI_DEV_EIOTLB_PASID(pasid) |
QI_DEV_EIOTLB_SID(sid) |
QI_DEV_EIOTLB_QDEP(qdep) |
QI_DEIOTLB_TYPE |
QI_DEV_IOTLB_PFSID(info->pfsid);
qi_retry:
reinit_completion(&iommu->prq_complete);
qi_submit_sync(iommu, desc, 3, QI_OPT_WAIT_DRAIN);
if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) {
wait_for_completion(&iommu->prq_complete);
goto qi_retry;
}
}
static irqreturn_t prq_event_thread(int irq, void *d)
{
struct intel_iommu *iommu = d;
......@@ -856,6 +943,16 @@ static irqreturn_t prq_event_thread(int irq, void *d)
dmar_writeq(iommu->reg + DMAR_PQH_REG, tail);
/*
* Clear the page request overflow bit and wake up all threads that
* are waiting for the completion of this handling.
*/
if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO)
writel(DMA_PRS_PRO, iommu->reg + DMAR_PRS_REG);
if (!completion_done(&iommu->prq_complete))
complete(&iommu->prq_complete);
return IRQ_RETVAL(handled);
}
......
......@@ -292,6 +292,8 @@
/* PRS_REG */
#define DMA_PRS_PPR ((u32)1)
#define DMA_PRS_PRO ((u32)2)
#define DMA_VCS_PAS ((u64)1)
#define IOMMU_WAIT_OP(iommu, offset, op, cond, sts) \
......@@ -333,6 +335,7 @@ enum {
#define QI_IWD_STATUS_DATA(d) (((u64)d) << 32)
#define QI_IWD_STATUS_WRITE (((u64)1) << 5)
#define QI_IWD_FENCE (((u64)1) << 6)
#define QI_IWD_PRQ_DRAIN (((u64)1) << 7)
#define QI_IOTLB_DID(did) (((u64)did) << 16)
......@@ -582,6 +585,7 @@ struct intel_iommu {
#ifdef CONFIG_INTEL_IOMMU_SVM
struct page_req_dsc *prq;
unsigned char prq_name[16]; /* Name for PRQ interrupt */
struct completion prq_complete;
struct ioasid_allocator_ops pasid_allocator; /* Custom allocator for PASIDs */
#endif
struct q_inval *qi; /* Queued invalidation info */
......
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