From: Jean-Philippe Brucker jean-philippe.brucker@arm.com
[ Upstream commit 8dd8f005bdd45823fc153ef490239558caf6ff20 ]
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 Acked-by: Will Deacon will@kernel.org Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/arm-smmu-v3.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
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); }