[POWERPC] Enable MSI mappings for MPIC

On some Apple machines the HT MSI mappings are not enabled by firmware, so
we need to do it by hand.

We can't use the pci routines as this code runs too early.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index e88bbd5ec4c8cfb4dc499e6002095c4c3cf366ee..33ecf89702d48aac072f1a5b167553472f6ff37a 100644 (file)
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -389,6 +389,50 @@ static void mpic_shutdown_ht_interrupt(struct mpic *mpic, unsigned int source,
 #endif
 }
 
+#ifdef CONFIG_PCI_MSI
+static void __init mpic_scan_ht_msi(struct mpic *mpic, u8 __iomem *devbase,
+                                   unsigned int devfn)
+{
+       u8 __iomem *base;
+       u8 pos, flags;
+       u64 addr = 0;
+
+       for (pos = readb(devbase + PCI_CAPABILITY_LIST); pos != 0;
+            pos = readb(devbase + pos + PCI_CAP_LIST_NEXT)) {
+               u8 id = readb(devbase + pos + PCI_CAP_LIST_ID);
+               if (id == PCI_CAP_ID_HT) {
+                       id = readb(devbase + pos + 3);
+                       if ((id & HT_5BIT_CAP_MASK) == HT_CAPTYPE_MSI_MAPPING)
+                               break;
+               }
+       }
+
+       if (pos == 0)
+               return;
+
+       base = devbase + pos;
+
+       flags = readb(base + HT_MSI_FLAGS);
+       if (!(flags & HT_MSI_FLAGS_FIXED)) {
+               addr = readl(base + HT_MSI_ADDR_LO) & HT_MSI_ADDR_LO_MASK;
+               addr = addr | ((u64)readl(base + HT_MSI_ADDR_HI) << 32);
+       }
+
+       printk(KERN_DEBUG "mpic:   - HT:%02x.%x %s MSI mapping found @ 0x%lx\n",
+               PCI_SLOT(devfn), PCI_FUNC(devfn),
+               flags & HT_MSI_FLAGS_ENABLE ? "enabled" : "disabled", addr);
+
+       if (!(flags & HT_MSI_FLAGS_ENABLE))
+               writeb(flags | HT_MSI_FLAGS_ENABLE, base + HT_MSI_FLAGS);
+}
+#else
+static void __init mpic_scan_ht_msi(struct mpic *mpic, u8 __iomem *devbase,
+                                   unsigned int devfn)
+{
+       return;
+}
+#endif
+
 static void __init mpic_scan_ht_pic(struct mpic *mpic, u8 __iomem *devbase,
                                    unsigned int devfn, u32 vdid)
 {
@@ -480,6 +524,7 @@ static void __init mpic_scan_ht_pics(struct mpic *mpic)
                        goto next;
 
                mpic_scan_ht_pic(mpic, devbase, devfn, l);
+               mpic_scan_ht_msi(mpic, devbase, devfn);
 
        next:
                /* next device, if function 0 */