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path: root/arch/powerpc/sysdev/mpic_u3msi.c
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Diffstat (limited to 'arch/powerpc/sysdev/mpic_u3msi.c')
-rw-r--r--arch/powerpc/sysdev/mpic_u3msi.c46
1 files changed, 39 insertions, 7 deletions
diff --git a/arch/powerpc/sysdev/mpic_u3msi.c b/arch/powerpc/sysdev/mpic_u3msi.c
index d3caf23e631..bcbfe79c704 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);