diff options
author | David Woodhouse <David.Woodhouse@intel.com> | 2015-10-07 23:35:18 +0100 |
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committer | David Woodhouse <David.Woodhouse@intel.com> | 2015-10-15 15:35:19 +0100 |
commit | a222a7f0bb6c94c31cc9c755110593656f19de89 (patch) | |
tree | 1609c5e92acbb8d1f3cbefda804a3e02fc013088 /drivers/iommu/intel-svm.c | |
parent | 1208225cf48fa3b170b6dfe7369f15c295260755 (diff) | |
download | op-kernel-dev-a222a7f0bb6c94c31cc9c755110593656f19de89.zip op-kernel-dev-a222a7f0bb6c94c31cc9c755110593656f19de89.tar.gz |
iommu/vt-d: Implement page request handling
Largely based on the driver-mode implementation by Jesse Barnes.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/iommu/intel-svm.c')
-rw-r--r-- | drivers/iommu/intel-svm.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index a64720b..0e86542 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -21,6 +21,10 @@ #include <linux/rculist.h> #include <linux/pci.h> #include <linux/pci-ats.h> +#include <linux/dmar.h> +#include <linux/interrupt.h> + +static irqreturn_t prq_event_thread(int irq, void *d); struct pasid_entry { u64 val; @@ -82,6 +86,66 @@ int intel_svm_free_pasid_tables(struct intel_iommu *iommu) return 0; } +#define PRQ_ORDER 0 + +int intel_svm_enable_prq(struct intel_iommu *iommu) +{ + struct page *pages; + int irq, ret; + + pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, PRQ_ORDER); + if (!pages) { + pr_warn("IOMMU: %s: Failed to allocate page request queue\n", + iommu->name); + return -ENOMEM; + } + iommu->prq = page_address(pages); + + irq = dmar_alloc_hwirq(DMAR_UNITS_SUPPORTED + iommu->seq_id, iommu->node, iommu); + if (irq <= 0) { + pr_err("IOMMU: %s: Failed to create IRQ vector for page request queue\n", + iommu->name); + ret = -EINVAL; + err: + free_pages((unsigned long)iommu->prq, PRQ_ORDER); + iommu->prq = NULL; + return ret; + } + iommu->pr_irq = irq; + + snprintf(iommu->prq_name, sizeof(iommu->prq_name), "dmar%d-prq", iommu->seq_id); + + ret = request_threaded_irq(irq, NULL, prq_event_thread, IRQF_ONESHOT, + iommu->prq_name, iommu); + if (ret) { + pr_err("IOMMU: %s: Failed to request IRQ for page request queue\n", + iommu->name); + dmar_free_hwirq(irq); + goto err; + } + dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER); + + return 0; +} + +int intel_svm_finish_prq(struct intel_iommu *iommu) +{ + dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL); + dmar_writeq(iommu->reg + DMAR_PQA_REG, 0ULL); + + free_irq(iommu->pr_irq, iommu); + dmar_free_hwirq(iommu->pr_irq); + iommu->pr_irq = 0; + + free_pages((unsigned long)iommu->prq, PRQ_ORDER); + iommu->prq = NULL; + + return 0; +} + static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_dev *sdev, unsigned long address, int pages, int ih) { @@ -363,3 +427,112 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) return ret; } EXPORT_SYMBOL_GPL(intel_svm_unbind_mm); + +/* Page request queue descriptor */ +struct page_req_dsc { + u64 srr:1; + u64 bof:1; + u64 pasid_present:1; + u64 lpig:1; + u64 pasid:20; + u64 bus:8; + u64 private:23; + u64 prg_index:9; + u64 rd_req:1; + u64 wr_req:1; + u64 exe_req:1; + u64 priv_req:1; + u64 devfn:8; + u64 addr:52; +}; + +#define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x10) +static irqreturn_t prq_event_thread(int irq, void *d) +{ + struct intel_iommu *iommu = d; + struct intel_svm *svm = NULL; + int head, tail, handled = 0; + + 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 vm_area_struct *vma; + struct page_req_dsc *req; + struct qi_desc resp; + int ret, result; + u64 address; + + handled = 1; + + req = &iommu->prq[head / sizeof(*req)]; + + result = QI_RESP_FAILURE; + address = req->addr << PAGE_SHIFT; + if (!req->pasid_present) { + pr_err("%s: Page request without PASID: %08llx %08llx\n", + iommu->name, ((unsigned long long *)req)[0], + ((unsigned long long *)req)[1]); + goto bad_req; + } + + if (!svm || svm->pasid != req->pasid) { + rcu_read_lock(); + svm = idr_find(&iommu->pasid_idr, req->pasid); + /* It *can't* go away, because the driver is not permitted + * to unbind the mm while any page faults are outstanding. + * So we only need RCU to protect the internal idr code. */ + rcu_read_unlock(); + + if (!svm) { + pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n", + iommu->name, req->pasid, ((unsigned long long *)req)[0], + ((unsigned long long *)req)[1]); + goto bad_req; + } + } + + result = QI_RESP_INVALID; + down_read(&svm->mm->mmap_sem); + vma = find_extend_vma(svm->mm, address); + if (!vma || address < vma->vm_start) + goto invalid; + + ret = handle_mm_fault(svm->mm, vma, address, + req->wr_req ? FAULT_FLAG_WRITE : 0); + if (ret & VM_FAULT_ERROR) + goto invalid; + + result = QI_RESP_SUCCESS; + invalid: + up_read(&svm->mm->mmap_sem); + bad_req: + /* Accounting for major/minor faults? */ + + if (req->lpig) { + /* Page Group Response */ + resp.low = QI_PGRP_PASID(req->pasid) | + QI_PGRP_DID((req->bus << 8) | req->devfn) | + QI_PGRP_PASID_P(req->pasid_present) | + QI_PGRP_RESP_TYPE; + resp.high = QI_PGRP_IDX(req->prg_index) | + QI_PGRP_PRIV(req->private) | QI_PGRP_RESP_CODE(result); + + qi_submit_sync(&resp, svm->iommu); + } else if (req->srr) { + /* Page Stream Response */ + resp.low = QI_PSTRM_IDX(req->prg_index) | + QI_PSTRM_PRIV(req->private) | QI_PSTRM_BUS(req->bus) | + QI_PSTRM_PASID(req->pasid) | QI_PSTRM_RESP_TYPE; + resp.high = QI_PSTRM_ADDR(address) | QI_PSTRM_DEVFN(req->devfn) | + QI_PSTRM_RESP_CODE(result); + + qi_submit_sync(&resp, svm->iommu); + } + + head = (head + sizeof(*req)) & PRQ_RING_MASK; + } + + dmar_writeq(iommu->reg + DMAR_PQH_REG, tail); + + return IRQ_RETVAL(handled); +} |