linux-kernel - [PATCH 02/12] iommu/vt-d: Remove for_each_device

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Message-Id: <20220527063019.3112905-3-baolu.lu@linux.intel.com>
Date:   Fri, 27 May 2022 14:30:09 +0800
From:   Lu Baolu <baolu.lu@...ux.intel.com>
To:     Joerg Roedel <joro@...tes.org>, Kevin Tian <kevin.tian@...el.com>,
        Ashok Raj <ashok.raj@...el.com>,
        Christoph Hellwig <hch@...radead.org>,
        Jason Gunthorpe <jgg@...dia.com>
Cc:     Will Deacon <will@...nel.org>, Robin Murphy <robin.murphy@....com>,
        Liu Yi L <yi.l.liu@...el.com>,
        Jacob jun Pan <jacob.jun.pan@...el.com>,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH 02/12] iommu/vt-d: Remove for_each_device_domain()

The per-device device_domain_info data could be retrieved from the
device itself. There's no need to search a global list.

Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
---
 drivers/iommu/intel/iommu.h |  2 --
 drivers/iommu/intel/iommu.c | 25 -------------------------
 drivers/iommu/intel/pasid.c | 37 +++++++++++--------------------------
 3 files changed, 11 insertions(+), 53 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 8a6d64d726c0..2f4a5b9509c0 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -727,8 +727,6 @@ extern int dmar_ir_support(void);
 void *alloc_pgtable_page(int node);
 void free_pgtable_page(void *vaddr);
 struct intel_iommu *domain_get_iommu(struct dmar_domain *domain);
-int for_each_device_domain(int (*fn)(struct device_domain_info *info,
-				     void *data), void *data);
 void iommu_flush_write_buffer(struct intel_iommu *iommu);
 int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev);
 struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn);
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cacae8bdaa65..6549b09d7f32 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -316,31 +316,6 @@ static int iommu_skip_te_disable;
 
 static DEFINE_SPINLOCK(device_domain_lock);
 static LIST_HEAD(device_domain_list);
-
-/*
- * Iterate over elements in device_domain_list and call the specified
- * callback @fn against each element.
- */
-int for_each_device_domain(int (*fn)(struct device_domain_info *info,
-				     void *data), void *data)
-{
-	int ret = 0;
-	unsigned long flags;
-	struct device_domain_info *info;
-
-	spin_lock_irqsave(&device_domain_lock, flags);
-	list_for_each_entry(info, &device_domain_list, global) {
-		ret = fn(info, data);
-		if (ret) {
-			spin_unlock_irqrestore(&device_domain_lock, flags);
-			return ret;
-		}
-	}
-	spin_unlock_irqrestore(&device_domain_lock, flags);
-
-	return 0;
-}
-
 const struct iommu_ops intel_iommu_ops;
 
 static bool translation_pre_enabled(struct intel_iommu *iommu)
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index b2ac5869286f..0627d6465f25 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -103,36 +103,20 @@ device_detach_pasid_table(struct device_domain_info *info,
 }
 
 struct pasid_table_opaque {
-	struct pasid_table	**pasid_table;
-	int			segment;
-	int			bus;
-	int			devfn;
+	struct pasid_table	*pasid_table;
 };
 
-static int search_pasid_table(struct device_domain_info *info, void *opaque)
-{
-	struct pasid_table_opaque *data = opaque;
-
-	if (info->iommu->segment == data->segment &&
-	    info->bus == data->bus &&
-	    info->devfn == data->devfn &&
-	    info->pasid_table) {
-		*data->pasid_table = info->pasid_table;
-		return 1;
-	}
-
-	return 0;
-}
-
 static int get_alias_pasid_table(struct pci_dev *pdev, u16 alias, void *opaque)
 {
 	struct pasid_table_opaque *data = opaque;
+	struct device_domain_info *info;
 
-	data->segment = pci_domain_nr(pdev->bus);
-	data->bus = PCI_BUS_NUM(alias);
-	data->devfn = alias & 0xff;
+	info = dev_iommu_priv_get(&pdev->dev);
+	if (!info || !info->pasid_table)
+		return 0;
 
-	return for_each_device_domain(&search_pasid_table, data);
+	data->pasid_table = info->pasid_table;
+	return 1;
 }
 
 /*
@@ -141,9 +125,9 @@ static int get_alias_pasid_table(struct pci_dev *pdev, u16 alias, void *opaque)
  */
 int intel_pasid_alloc_table(struct device *dev)
 {
+	struct pasid_table_opaque data = { NULL };
 	struct device_domain_info *info;
 	struct pasid_table *pasid_table;
-	struct pasid_table_opaque data;
 	struct page *pages;
 	u32 max_pasid = 0;
 	int ret, order;
@@ -155,11 +139,12 @@ int intel_pasid_alloc_table(struct device *dev)
 		return -EINVAL;
 
 	/* DMA alias device already has a pasid table, use it: */
-	data.pasid_table = &pasid_table;
 	ret = pci_for_each_dma_alias(to_pci_dev(dev),
 				     &get_alias_pasid_table, &data);
-	if (ret)
+	if (ret) {
+		pasid_table = data.pasid_table;
 		goto attach_out;
+	}
 
 	pasid_table = kzalloc(sizeof(*pasid_table), GFP_KERNEL);
 	if (!pasid_table)
-- 
2.25.1