Re: [PATCH v2 3/5] PCI: iproc: Disable MSI parsing in certain PAXC blocks

[poza]

On 2018-06-12 05:51, Ray Jui wrote:

The internal MSI parsing logic in certain revisions of PAXC root
complexes does not work properly and can casue corruptions on the
writes. They need to be disabled

Signed-off-by: Ray Jui <ray....@broadcom.com>
Reviewed-by: Scott Branden <scott.bran...@broadcom.com>
---
 drivers/pci/host/pcie-iproc.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c

index 680f6b1..0804aa2 100644
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -1197,10 +1197,22 @@ static int iproc_pcie_paxb_v2_msi_steer(struct
iproc_pcie *pcie, u64 msi_addr)
        return ret;
 }

-static void iproc_pcie_paxc_v2_msi_steer(struct iproc_pcie *pcie, u64 msi_addr) +static void iproc_pcie_paxc_v2_msi_steer(struct iproc_pcie *pcie, u64 msi_addr,

+                                        bool enable)
 {
        u32 val;

+       if (!enable) {
+               /*
+                * Disable PAXC MSI steering. All write transfers will be
+                * treated as non-MSI transfers
+                */
+               val = iproc_pcie_read_reg(pcie, IPROC_PCIE_MSI_EN_CFG);
+               val &= ~MSI_ENABLE_CFG;
+               iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_EN_CFG, val);
+               return;

can be dropped.

+       }
+
        /*
         * Program bits [43:13] of address of GITS_TRANSLATER register into

* bits [30:0] of the MSI base address register. In fact, in all iProc @@ -1254,7 +1266,7 @@ static int iproc_pcie_msi_steer(struct iproc_pcie *pcie,

                        return ret;
                break;
        case IPROC_PCIE_PAXC_V2:
-               iproc_pcie_paxc_v2_msi_steer(pcie, msi_addr);
+               iproc_pcie_paxc_v2_msi_steer(pcie, msi_addr, true);
                break;
        default:
                return -EINVAL;
@@ -1480,6 +1492,24 @@ int iproc_pcie_remove(struct iproc_pcie *pcie)
 }
 EXPORT_SYMBOL(iproc_pcie_remove);

+/*

+ * The MSI parsing logic in certain revisions of Broadcom PAXC based root

+ * complex does not work and needs to be disabled
+ */
+static void quirk_paxc_disable_msi_parsing(struct pci_dev *pdev)
+{
+       struct iproc_pcie *pcie = iproc_data(pdev->bus);
+
+       if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
+               iproc_pcie_paxc_v2_msi_steer(pcie, 0, false);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_BROADCOM, 0x16f0,
+                       quirk_paxc_disable_msi_parsing);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_BROADCOM, 0xd802,
+                       quirk_paxc_disable_msi_parsing);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_BROADCOM, 0xd804,
+                       quirk_paxc_disable_msi_parsing);
+
 MODULE_AUTHOR("Ray Jui <r...@broadcom.com>");
 MODULE_DESCRIPTION("Broadcom iPROC PCIe common driver");
 MODULE_LICENSE("GPL v2");