powerpc/85xx: workaround for chips with MSI hardware errata

[linux-2.6-microblaze.git] / arch / powerpc / sysdev / fsl_msi.c

diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index 4bbb4b8..f086c6f 100644 (file)
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -162,7 +162,17 @@ static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
        msg->address_lo = lower_32_bits(address);
        msg->address_hi = upper_32_bits(address);
 
-       msg->data = hwirq;
+       /*
+        * MPIC version 2.0 has erratum PIC1. It causes
+        * that neither MSI nor MSI-X can work fine.
+        * This is a workaround to allow MSI-X to function
+        * properly. It only works for MSI-X, we prevent
+        * MSI on buggy chips in fsl_setup_msi_irqs().
+        */
+       if (msi_data->feature & MSI_HW_ERRATA_ENDIAN)
+               msg->data = __swab32(hwirq);
+       else
+               msg->data = hwirq;
 
        pr_debug("%s: allocated srs: %d, ibs: %d\n", __func__,
                 (hwirq >> msi_data->srs_shift) & MSI_SRS_MASK,
@@ -180,8 +190,16 @@ static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
        struct msi_msg msg;
        struct fsl_msi *msi_data;
 
-       if (type == PCI_CAP_ID_MSIX)
-               pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
+       if (type == PCI_CAP_ID_MSI) {
+               /*
+                * MPIC version 2.0 has erratum PIC1. For now MSI
+                * could not work. So check to prevent MSI from
+                * being used on the board with this erratum.
+                */
+               list_for_each_entry(msi_data, &msi_head, list)
+                       if (msi_data->feature & MSI_HW_ERRATA_ENDIAN)
+                               return -EINVAL;
+       }
 
        /*
         * If the PCI node has an fsl,msi property, then we need to use it
@@ -446,6 +464,11 @@ static int fsl_of_msi_probe(struct platform_device *dev)
 
        msi->feature = features->fsl_pic_ip;
 
+       /* For erratum PIC1 on MPIC version 2.0*/
+       if ((features->fsl_pic_ip & FSL_PIC_IP_MASK) == FSL_PIC_IP_MPIC
+                       && (fsl_mpic_primary_get_version() == 0x0200))
+               msi->feature |= MSI_HW_ERRATA_ENDIAN;
+
        /*
         * Remember the phandle, so that we can match with any PCI nodes
         * that have an "fsl,msi" property.