From 299bd044a6f332b4a6c8f708575c27cad70a35c1 Mon Sep 17 00:00:00 2001
From: Raymond Pang <RaymondPang-oc@zhaoxin.com>
Date: Fri, 27 Mar 2020 17:11:48 +0800
Subject: [PATCH] PCI: Add ACS quirk for Zhaoxin Root/Downstream Ports
Git-commit: 299bd044a6f332b4a6c8f708575c27cad70a35c1
Patch-mainline: v5.7-rc1
References: git-fixes
Many Zhaoxin Root Ports and Switch Downstream Ports do provide ACS-like
capability but have no ACS Capability Structure. Peer-to-Peer transactions
could be blocked between these ports, so add quirk so devices behind them
could be assigned to different IOMMU group.
Link: https://lore.kernel.org/r/20200327091148.5190-4-RaymondPang-oc@zhaoxin.com
Signed-off-by: Raymond Pang <RaymondPang-oc@zhaoxin.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/pci/quirks.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 7bdd0f5e4b7b..b0de6dff50d3 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4399,6 +4399,29 @@ static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
}
+/*
+ * Many Zhaoxin Root Ports and Switch Downstream Ports have no ACS capability.
+ * But the implementation could block peer-to-peer transactions between them
+ * and provide ACS-like functionality.
+ */
+static int pci_quirk_zhaoxin_pcie_ports_acs(struct pci_dev *dev, u16 acs_flags)
+{
+ if (!pci_is_pcie(dev) ||
+ ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
+ (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
+ return -ENOTTY;
+
+ switch (dev->device) {
+ case 0x0710 ... 0x071e:
+ case 0x0721:
+ case 0x0723 ... 0x0732:
+ return pci_acs_ctrl_enabled(acs_flags,
+ PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
+ }
+
+ return false;
+}
+
/*
* Many Intel PCH Root Ports do provide ACS-like features to disable peer
* transactions and validate bus numbers in requests, but do not provide an
@@ -4705,6 +4728,8 @@ static const struct pci_dev_acs_enabled {
{ PCI_VENDOR_ID_ZHAOXIN, 0x3038, pci_quirk_mf_endpoint_acs },
{ PCI_VENDOR_ID_ZHAOXIN, 0x3104, pci_quirk_mf_endpoint_acs },
{ PCI_VENDOR_ID_ZHAOXIN, 0x9083, pci_quirk_mf_endpoint_acs },
+ /* Zhaoxin Root/Downstream Ports */
+ { PCI_VENDOR_ID_ZHAOXIN, PCI_ANY_ID, pci_quirk_zhaoxin_pcie_ports_acs },
{ 0 }
};
--
2.16.4