From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 95A0C15AC for ; Wed, 14 Sep 2022 01:24:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1663118653; x=1694654653; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=DJEO4d3itpLXefVeSwtwe65EXfogPWLWr30ciCn+U7I=; b=hG6eQ7daKhXfutPynxdVpsPaTLLz6z3DkBg9H5xk425CkPvXkadMpS8I nIDY2qat+j5W5YlXgOl71YdydNIrJGkGk5tzeEnEFObvs52VAlXzDX1qb 0DaPeJVcJ/64JN86U4R8BRayI83He5dds4QvHi3Bhz5AASbKotPJW/cI2 Z7+vupozL+GN+H5AAAi7uR3cixPtWu8x6Idmx9YRkxd3xFWTERjFibFJ9 LVy3Kxqh+p7sviSaK9H9VrGh/H/P2meud/gDMws6ntS1sxsLf2MLgEO4Q 2vsxUPlJx68UgkBQKxFpPA+dw+C8j9kWoDg302IQeUqqIOpkcX6mk2tJP g==; X-IronPort-AV: E=McAfee;i="6500,9779,10469"; a="384597208" X-IronPort-AV: E=Sophos;i="5.93,313,1654585200"; d="scan'208";a="384597208" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Sep 2022 18:24:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.93,313,1654585200"; d="scan'208";a="619136474" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga007.fm.intel.com with ESMTP; 13 Sep 2022 18:24:10 -0700 From: Lu Baolu To: iommu@lists.linux.dev Cc: Joerg Roedel , Will Deacon , Robin Murphy , Kevin Tian , linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v2 1/1] iommu/vt-d: Remove unnecessary SVA data accesses in page fault path Date: Wed, 14 Sep 2022 09:18:21 +0800 Message-Id: <20220914011821.400986-1-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The existing I/O page fault handling code accesses the per-PASID SVA data structures. This is unnecessary and makes the fault handling code only suitable for SVA scenarios. This removes the SVA data accesses from the I/O page fault reporting and responding code, so that the fault handling code could be generic. Signed-off-by: Lu Baolu --- drivers/iommu/intel/iommu.h | 2 +- drivers/iommu/intel/svm.c | 60 +++++-------------------------------- 2 files changed, 8 insertions(+), 54 deletions(-) Change log: v2: - Move prq_seq_number to per-iommu data struct. - Add back the comments that were accidentally deleted. - Rephrased the commit message. v1: https://lore.kernel.org/linux-iommu/20220908023557.4582-1-baolu.lu@linux.intel.com/ diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 08618d94fbac..352f05e92f6f 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -584,6 +584,7 @@ struct intel_iommu { #ifdef CONFIG_INTEL_IOMMU_SVM struct page_req_dsc *prq; unsigned char prq_name[16]; /* Name for PRQ interrupt */ + unsigned long prq_seq_number; struct completion prq_complete; struct ioasid_allocator_ops pasid_allocator; /* Custom allocator for PASIDs */ #endif @@ -757,7 +758,6 @@ struct intel_svm_dev { struct device *dev; struct intel_iommu *iommu; struct iommu_sva sva; - unsigned long prq_seq_number; u32 pasid; int users; u16 did; diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index b391e46e537e..e73b9a202777 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -48,23 +48,6 @@ static void *pasid_private_find(ioasid_t pasid) return xa_load(&pasid_private_array, pasid); } -static struct intel_svm_dev * -svm_lookup_device_by_sid(struct intel_svm *svm, u16 sid) -{ - struct intel_svm_dev *sdev = NULL, *t; - - rcu_read_lock(); - list_for_each_entry_rcu(t, &svm->devs, list) { - if (t->sid == sid) { - sdev = t; - break; - } - } - rcu_read_unlock(); - - return sdev; -} - static struct intel_svm_dev * svm_lookup_device_by_dev(struct intel_svm *svm, struct device *dev) { @@ -689,11 +672,10 @@ static void handle_bad_prq_event(struct intel_iommu *iommu, static irqreturn_t prq_event_thread(int irq, void *d) { - struct intel_svm_dev *sdev = NULL; struct intel_iommu *iommu = d; - struct intel_svm *svm = NULL; struct page_req_dsc *req; int head, tail, handled; + struct pci_dev *pdev; u64 address; /* @@ -713,8 +695,6 @@ static irqreturn_t prq_event_thread(int irq, void *d) pr_err("IOMMU: %s: Page request without PASID\n", iommu->name); bad_req: - svm = NULL; - sdev = NULL; handle_bad_prq_event(iommu, req, QI_RESP_INVALID); goto prq_advance; } @@ -741,34 +721,19 @@ static irqreturn_t prq_event_thread(int irq, void *d) if (unlikely(req->lpig && !req->rd_req && !req->wr_req)) goto prq_advance; - if (!svm || svm->pasid != req->pasid) { - /* - * It can't go away, because the driver is not permitted - * to unbind the mm while any page faults are outstanding. - */ - svm = pasid_private_find(req->pasid); - if (IS_ERR_OR_NULL(svm)) - goto bad_req; - } - - if (!sdev || sdev->sid != req->rid) { - sdev = svm_lookup_device_by_sid(svm, req->rid); - if (!sdev) - goto bad_req; - } - - sdev->prq_seq_number++; - + pdev = pci_get_domain_bus_and_slot(iommu->segment, + PCI_BUS_NUM(req->rid), + req->rid & 0xff); /* * If prq is to be handled outside iommu driver via receiver of * the fault notifiers, we skip the page response here. */ - if (intel_svm_prq_report(iommu, sdev->dev, req)) + if (!pdev || intel_svm_prq_report(iommu, &pdev->dev, req)) handle_bad_prq_event(iommu, req, QI_RESP_INVALID); - trace_prq_report(iommu, sdev->dev, req->qw_0, req->qw_1, + trace_prq_report(iommu, &pdev->dev, req->qw_0, req->qw_1, req->priv_data[0], req->priv_data[1], - sdev->prq_seq_number); + iommu->prq_seq_number++); prq_advance: head = (head + sizeof(*req)) & PRQ_RING_MASK; } @@ -803,8 +768,6 @@ int intel_svm_page_response(struct device *dev, struct iommu_page_response *msg) { struct iommu_fault_page_request *prm; - struct intel_svm_dev *sdev = NULL; - struct intel_svm *svm = NULL; struct intel_iommu *iommu; bool private_present; bool pasid_present; @@ -823,8 +786,6 @@ int intel_svm_page_response(struct device *dev, if (!msg || !evt) return -EINVAL; - mutex_lock(&pasid_mutex); - prm = &evt->fault.prm; sid = PCI_DEVID(bus, devfn); pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID; @@ -841,12 +802,6 @@ int intel_svm_page_response(struct device *dev, goto out; } - ret = pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev); - if (ret || !sdev) { - ret = -ENODEV; - goto out; - } - /* * Per VT-d spec. v3.0 ch7.7, system software must respond * with page group response if private data is present (PDP) @@ -876,7 +831,6 @@ int intel_svm_page_response(struct device *dev, qi_submit_sync(iommu, &desc, 1, 0); } out: - mutex_unlock(&pasid_mutex); return ret; } -- 2.34.1