[PATCH v2 3/7] PCI/ACS: Enable PCI_ACS_TB for untrusted/external-facing devices

Rajat Jain
2020-06-30T04:49:59Z

When enabling ACS, enable translation blocking for external facing ports
and untrusted devices.

Signed-off-by: Rajat Jain <rajatja@google.com>
---
v2: Commit log change

drivers/pci/pci.c | 4 ++++
drivers/pci/quirks.c | 11 +++++++++++
2 files changed, 15 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d2ff987585855..79853b52658a2 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3330,6 +3330,10 @@ static void pci_std_enable_acs(struct pci_dev *dev)
/* Upstream Forwarding */
ctrl |= (cap & PCI_ACS_UF);

+ if (dev->external_facing || dev->untrusted)
+ /* Translation Blocking */
+ ctrl |= (cap & PCI_ACS_TB);
+
pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
}

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b341628e47527..6294adeac4049 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4934,6 +4934,13 @@ static void pci_quirk_enable_intel_rp_mpc_acs(struct pci_dev *dev)
}
}

+/*
+ * Currently this quirk does the equivalent of
+ * PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_SV
+ *
+ * Currently missing, it also needs to do equivalent of PCI_ACS_TB,
+ * if dev->external_facing || dev->untrusted
+ */
static int pci_quirk_enable_intel_pch_acs(struct pci_dev *dev)
{
if (!pci_quirk_intel_pch_acs_match(dev))
@@ -4973,6 +4980,10 @@ static int pci_quirk_enable_intel_spt_pch_acs(struct pci_dev *dev)
ctrl |= (cap & PCI_ACS_CR);
ctrl |= (cap & PCI_ACS_UF);

+ if (dev->external_facing || dev->untrusted)
+ /* Translation Blocking */
+ ctrl |= (cap & PCI_ACS_TB);
+
pci_write_config_dword(dev, pos + INTEL_SPT_ACS_CTRL, ctrl);

pci_info(dev, "Intel SPT PCH root port ACS workaround enabled\n");
--
2.27.0.212.ge8ba1cc988-goog