Merge branch 'pci/virtualization'

- Avoid bus resets on Atheros QCA6174, since they hang (Ingmar Klein)

- Use store and forward mode on Pericom PI7C9X2G switches to avoid ACS
  erratum with ACS P2P Request Redirect (Nathan Rossi)

* pci/virtualization:
  PCI: Add ACS quirk for Pericom PI7C9X2G switches
  PCI: Mark Atheros QCA6174 to avoid bus reset

1 files changed, 56 insertions, 0 deletions

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 4537d1ea14fd..126c256bbb8a 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3612,6 +3612,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0032, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003c, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0033, quirk_no_bus_reset);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034, quirk_no_bus_reset);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003e, quirk_no_bus_reset);
 
 /*
  * Root port on some Cavium CN8xxx chips do not successfully complete a bus
@@ -5795,3 +5796,58 @@ static void apex_pci_fixup_class(struct pci_dev *pdev)
 }
 DECLARE_PCI_FIXUP_CLASS_HEADER(0x1ac1, 0x089a,
 			       PCI_CLASS_NOT_DEFINED, 8, apex_pci_fixup_class);
+
+/*
+ * Pericom PI7C9X2G404/PI7C9X2G304/PI7C9X2G303 switch erratum E5 -
+ * ACS P2P Request Redirect is not functional
+ *
+ * When ACS P2P Request Redirect is enabled and bandwidth is not balanced
+ * between upstream and downstream ports, packets are queued in an internal
+ * buffer until CPLD packet. The workaround is to use the switch in store and
+ * forward mode.
+ */
+#define PI7C9X2Gxxx_MODE_REG		0x74
+#define PI7C9X2Gxxx_STORE_FORWARD_MODE	BIT(0)
+static void pci_fixup_pericom_acs_store_forward(struct pci_dev *pdev)
+{
+	struct pci_dev *upstream;
+	u16 val;
+
+	/* Downstream ports only */
+	if (pci_pcie_type(pdev) != PCI_EXP_TYPE_DOWNSTREAM)
+		return;
+
+	/* Check for ACS P2P Request Redirect use */
+	if (!pdev->acs_cap)
+		return;
+	pci_read_config_word(pdev, pdev->acs_cap + PCI_ACS_CTRL, &val);
+	if (!(val & PCI_ACS_RR))
+		return;
+
+	upstream = pci_upstream_bridge(pdev);
+	if (!upstream)
+		return;
+
+	pci_read_config_word(upstream, PI7C9X2Gxxx_MODE_REG, &val);
+	if (!(val & PI7C9X2Gxxx_STORE_FORWARD_MODE)) {
+		pci_info(upstream, "Setting PI7C9X2Gxxx store-forward mode to avoid ACS erratum\n");
+		pci_write_config_word(upstream, PI7C9X2Gxxx_MODE_REG, val |
+				      PI7C9X2Gxxx_STORE_FORWARD_MODE);
+	}
+}
+/*
+ * Apply fixup on enable and on resume, in order to apply the fix up whenever
+ * ACS configuration changes or switch mode is reset
+ */
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_PERICOM, 0x2404,
+			 pci_fixup_pericom_acs_store_forward);
+DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_PERICOM, 0x2404,
+			 pci_fixup_pericom_acs_store_forward);
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_PERICOM, 0x2304,
+			 pci_fixup_pericom_acs_store_forward);
+DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_PERICOM, 0x2304,
+			 pci_fixup_pericom_acs_store_forward);
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_PERICOM, 0x2303,
+			 pci_fixup_pericom_acs_store_forward);
+DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_PERICOM, 0x2303,
+			 pci_fixup_pericom_acs_store_forward);