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* [PATCH v4] iommu/of: Fix pci_request_acs() before enumerating PCI devices
@ 2021-05-21  3:03 Wang Xingang
  2021-05-21 19:03 ` Rob Herring
                   ` (4 more replies)
  0 siblings, 5 replies; 15+ messages in thread
From: Wang Xingang @ 2021-05-21  3:03 UTC (permalink / raw)
  To: robh, will, joro, helgaas
  Cc: robh+dt, gregkh, iommu, linux-kernel, linux-pci, xieyingtai,
	wangxingang5

From: Xingang Wang <wangxingang5@huawei.com>

When booting with devicetree, the pci_request_acs() is called after the
enumeration and initialization of PCI devices, thus the ACS is not
enabled. And ACS should be enabled when IOMMU is detected for the
PCI host bridge, so add check for IOMMU before probe of PCI host and call
pci_request_acs() to make sure ACS will be enabled when enumerating PCI
devices.

Fixes: 6bf6c24720d33 ("iommu/of: Request ACS from the PCI core when
configuring IOMMU linkage")
Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
---
 drivers/iommu/of_iommu.c | 1 -
 drivers/pci/of.c         | 8 +++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index a9d2df001149..54a14da242cc 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -205,7 +205,6 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 			.np = master_np,
 		};
 
-		pci_request_acs();
 		err = pci_for_each_dma_alias(to_pci_dev(dev),
 					     of_pci_iommu_init, &info);
 	} else {
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index da5b414d585a..2313c3f848b0 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -581,9 +581,15 @@ static int pci_parse_request_of_pci_ranges(struct device *dev,
 
 int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge)
 {
-	if (!dev->of_node)
+	struct device_node *node = dev->of_node;
+
+	if (!node)
 		return 0;
 
+	/* Detect IOMMU and make sure ACS will be enabled */
+	if (of_property_read_bool(node, "iommu-map"))
+		pci_request_acs();
+
 	bridge->swizzle_irq = pci_common_swizzle;
 	bridge->map_irq = of_irq_parse_and_map_pci;
 
-- 
2.19.1


^ permalink raw reply related	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2021-09-02 14:46 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-21  3:03 [PATCH v4] iommu/of: Fix pci_request_acs() before enumerating PCI devices Wang Xingang
2021-05-21 19:03 ` Rob Herring
2021-05-31 11:24   ` Xingang Wang
2021-06-04 15:36 ` Joerg Roedel
2021-06-07 12:43   ` Xingang Wang
2021-06-04 19:04 ` Bjorn Helgaas
2021-06-07 12:58   ` Xingang Wang
2021-06-08 10:23     ` John Garry
2021-06-28 13:20     ` Xingang Wang
2021-08-20 19:57 ` Bjorn Helgaas
2021-09-02 14:46   ` Bjorn Helgaas
     [not found] ` <CGME20210901085937eucas1p2d02da65cac797706ca3a10b8a2eb8ba2@eucas1p2.samsung.com>
2021-09-01  8:59   ` Marek Szyprowski
2021-09-01  9:58     ` Robin Murphy
2021-09-02 12:51       ` Anders Roxell
2021-09-02 13:07         ` Robin Murphy

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