2 files changed, 49 insertions, 8 deletions

diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c
index 1d44eee80fa1..0f67cd79d481 100644
--- a/arch/powerpc/sysdev/mpic_msi.c
+++ b/arch/powerpc/sysdev/mpic_msi.c
@@ -39,7 +39,12 @@ static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
 
         pr_debug("mpic: found U3, guessing msi allocator setup\n");
 
-        /* Reserve source numbers we know are reserved in the HW */
+        /* Reserve source numbers we know are reserved in the HW.
+         *
+         * This is a bit of a mix of U3 and U4 reserves but that's going
+         * to work fine, we have plenty enugh numbers left so let's just
+         * mark anything we don't like reserved.
+         */
         for (i = 0;   i < 8;   i++)
                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
 
@@ -49,6 +54,10 @@ static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
         for (i = 100; i < 105; i++)
                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
 
+        for (i = 124; i < mpic->irq_count; i++)
+                msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
+
+
         np = NULL;
         while ((np = of_find_all_nodes(np))) {
                 pr_debug("mpic: mapping hwirqs for %s\n", np->full_name);
diff --git a/arch/powerpc/sysdev/mpic_u3msi.c b/arch/powerpc/sysdev/mpic_u3msi.c
index d3caf23e6312..bcbfe79c704b 100644
--- a/arch/powerpc/sysdev/mpic_u3msi.c
+++ b/arch/powerpc/sysdev/mpic_u3msi.c
@@ -64,12 +64,12 @@ static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
         return addr;
 }
 
-static u64 find_ht_magic_addr(struct pci_dev *pdev)
+static u64 find_ht_magic_addr(struct pci_dev *pdev, unsigned int hwirq)
 {
         struct pci_bus *bus;
         unsigned int pos;
 
-        for (bus = pdev->bus; bus; bus = bus->parent) {
+        for (bus = pdev->bus; bus && bus->self; bus = bus->parent) {
                 pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING);
                 if (pos)
                         return read_ht_magic_addr(bus->self, pos);
@@ -78,13 +78,41 @@ static u64 find_ht_magic_addr(struct pci_dev *pdev)
         return 0;
 }
 
+static u64 find_u4_magic_addr(struct pci_dev *pdev, unsigned int hwirq)
+{
+        struct pci_controller *hose = pci_bus_to_host(pdev->bus);
+
+        /* U4 PCIe MSIs need to write to the special register in
+         * the bridge that generates interrupts. There should be
+         * theorically a register at 0xf8005000 where you just write
+         * the MSI number and that triggers the right interrupt, but
+         * unfortunately, this is busted in HW, the bridge endian swaps
+         * the value and hits the wrong nibble in the register.
+         *
+         * So instead we use another register set which is used normally
+         * for converting HT interrupts to MPIC interrupts, which decodes
+         * the interrupt number as part of the low address bits
+         *
+         * This will not work if we ever use more than one legacy MSI in
+         * a block but we never do. For one MSI or multiple MSI-X where
+         * each interrupt address can be specified separately, it works
+         * just fine.
+         */
+        if (of_device_is_compatible(hose->dn, "u4-pcie") ||
+            of_device_is_compatible(hose->dn, "U4-pcie"))
+                return 0xf8004000 | (hwirq << 4);
+
+        return 0;
+}
+
 static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
 {
         if (type == PCI_CAP_ID_MSIX)
                 pr_debug("u3msi: MSI-X untested, trying anyway.\n");
 
         /* If we can't find a magic address then MSI ain't gonna work */
-        if (find_ht_magic_addr(pdev) == 0) {
+        if (find_ht_magic_addr(pdev, 0) == 0 &&
+            find_u4_magic_addr(pdev, 0) == 0) {
                 pr_debug("u3msi: no magic address found for %s\n",
                          pci_name(pdev));
                 return -ENXIO;
@@ -118,10 +146,6 @@ static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
         u64 addr;
         int hwirq;
 
-        addr = find_ht_magic_addr(pdev);
-        msg.address_lo = addr & 0xFFFFFFFF;
-        msg.address_hi = addr >> 32;
-
         list_for_each_entry(entry, &pdev->msi_list, list) {
                 hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap, 1);
                 if (hwirq < 0) {
@@ -129,6 +153,12 @@ static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
                         return hwirq;
                 }
 
+                addr = find_ht_magic_addr(pdev, hwirq);
+                if (addr == 0)
+                        addr = find_u4_magic_addr(pdev, hwirq);
+                msg.address_lo = addr & 0xFFFFFFFF;
+                msg.address_hi = addr >> 32;
+
                 virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
                 if (virq == NO_IRQ) {
                         pr_debug("u3msi: failed mapping hwirq 0x%x\n", hwirq);
@@ -143,6 +173,8 @@ static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
                 pr_debug("u3msi: allocated virq 0x%x (hw 0x%x) addr 0x%lx\n",
                           virq, hwirq, (unsigned long)addr);
 
+                printk("u3msi: allocated virq 0x%x (hw 0x%x) addr 0x%lx\n",
+                          virq, hwirq, (unsigned long)addr);
                 msg.data = hwirq;
                 write_msi_msg(virq, &msg);