On 2020-10-15 05:13, Nicolin Chen wrote:
On Wed, Oct 14, 2020 at 06:42:36PM +0100, Robin Murphy wrote:
On 2020-10-09 17:19, Nicolin Chen wrote:
This patch simply adds support for PCI devices.
Reviewed-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Tested-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Signed-off-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx>
---
Changelog
v6->v7
* Renamed goto labels, suggested by Thierry.
v5->v6
* Added Dmitry's Reviewed-by and Tested-by.
v4->v5
* Added Dmitry's Reviewed-by
v3->v4
* Dropped !iommu_present() check
* Added CONFIG_PCI check in the exit path
v2->v3
* Replaced ternary conditional operator with if-else in .device_group()
* Dropped change in tegra_smmu_remove()
v1->v2
* Added error-out labels in tegra_smmu_probe()
* Dropped pci_request_acs() since IOMMU core would call it.
drivers/iommu/tegra-smmu.c | 35 +++++++++++++++++++++++++----------
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index be29f5977145..2941d6459076 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
@@ -865,7 +866,11 @@ static struct iommu_group *tegra_smmu_device_group(struct device *dev)
group->smmu = smmu;
group->soc = soc;
- group->group = iommu_group_alloc();
+ if (dev_is_pci(dev))
+ group->group = pci_device_group(dev);
Just to check, is it OK to have two or more swgroups "owning" the same
iommu_group if an existing one gets returned here? It looks like that might
not play nice with the use of iommu_group_set_iommudata().
Do you mean by "gets returned here" the "IS_ERR" check below?
I mean that unlike iommu_group_alloc()/generic_device_group(),
pci_device_group() may give you back a group that already contains
another device and has already been set up from that device's
perspective. This can happen for topological reasons like requester ID
aliasing through a PCI-PCIe bridge or lack of isolation between functions.
Robin.
+ else
+ group->group = generic_device_group(dev);
+
if (IS_ERR(group->group)) {
devm_kfree(smmu->dev, group);
mutex_unlock(&smmu->lock);
