| Message ID | 20190703111920.23637-1-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 8dd8f005bdd45823fc153ef490239558caf6ff20 |
| Headers | show |
| Series | iommu/arm-smmu-v3: Invalidate ATC when detaching a device | expand |
On Wed, Jul 03, 2019 at 12:19:20PM +0100, Jean-Philippe Brucker wrote: > We make the invalid assumption in arm_smmu_detach_dev() that the ATC is > clear after calling pci_disable_ats(). For one thing, only enabling the > PCIe ATS capability constitutes an implicit invalidation event, so the > comment was wrong. More importantly, the ATS capability isn't necessarily > disabled by pci_disable_ats() in a PF, if the associated VFs have ATS > enabled. Explicitly invalidate all ATC entries in arm_smmu_detach_dev(). > The endpoint cannot form new ATC entries because STE.EATS is clear. > > Fixes: 9ce27afc0830 ("iommu/arm-smmu-v3: Add support for PCI ATS") > Reported-by: Manoj Kumar <Manoj.Kumar3@arm.com> > Reported-by: Robin Murphy <Robin.Murphy@arm.com> > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > --- > drivers/iommu/arm-smmu-v3.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Acked-by: Will Deacon <will@kernel.org> Hopefully Joerg can add this to his queue for 5.3. Thanks, Will
On Wed, Jul 03, 2019 at 12:19:20PM +0100, Jean-Philippe Brucker wrote: > drivers/iommu/arm-smmu-v3.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Applied, thanks.
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 4d5a694f02c2..0fee8f7957ec 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1884,9 +1884,13 @@ static int arm_smmu_enable_ats(struct arm_smmu_master *master) static void arm_smmu_disable_ats(struct arm_smmu_master *master) { + struct arm_smmu_cmdq_ent cmd; + if (!master->ats_enabled || !dev_is_pci(master->dev)) return; + arm_smmu_atc_inv_to_cmd(0, 0, 0, &cmd); + arm_smmu_atc_inv_master(master, &cmd); pci_disable_ats(to_pci_dev(master->dev)); master->ats_enabled = false; } @@ -1906,7 +1910,6 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master) master->domain = NULL; arm_smmu_install_ste_for_dev(master); - /* Disabling ATS invalidates all ATC entries */ arm_smmu_disable_ats(master); }
We make the invalid assumption in arm_smmu_detach_dev() that the ATC is clear after calling pci_disable_ats(). For one thing, only enabling the PCIe ATS capability constitutes an implicit invalidation event, so the comment was wrong. More importantly, the ATS capability isn't necessarily disabled by pci_disable_ats() in a PF, if the associated VFs have ATS enabled. Explicitly invalidate all ATC entries in arm_smmu_detach_dev(). The endpoint cannot form new ATC entries because STE.EATS is clear. Fixes: 9ce27afc0830 ("iommu/arm-smmu-v3: Add support for PCI ATS") Reported-by: Manoj Kumar <Manoj.Kumar3@arm.com> Reported-by: Robin Murphy <Robin.Murphy@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> --- drivers/iommu/arm-smmu-v3.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)