Initial import

1 files changed, 201 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/mpic_u3msi.c b/arch/powerpc/sysdev/mpic_u3msi.c
new file mode 100644
index 000000000..b2cef1809
--- /dev/null
+++ b/arch/powerpc/sysdev/mpic_u3msi.c
@@ -0,0 +1,201 @@
+/*
+ * Copyright 2006, Segher Boessenkool, IBM Corporation.
+ * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2 of the
+ * License.
+ *
+ */
+
+#include <linux/irq.h>
+#include <linux/msi.h>
+#include <asm/mpic.h>
+#include <asm/prom.h>
+#include <asm/hw_irq.h>
+#include <asm/ppc-pci.h>
+#include <asm/msi_bitmap.h>
+
+#include "mpic.h"
+
+/* A bit ugly, can we get this from the pci_dev somehow? */
+static struct mpic *msi_mpic;
+
+static void mpic_u3msi_mask_irq(struct irq_data *data)
+{
+	pci_msi_mask_irq(data);
+	mpic_mask_irq(data);
+}
+
+static void mpic_u3msi_unmask_irq(struct irq_data *data)
+{
+	mpic_unmask_irq(data);
+	pci_msi_unmask_irq(data);
+}
+
+static struct irq_chip mpic_u3msi_chip = {
+	.irq_shutdown		= mpic_u3msi_mask_irq,
+	.irq_mask		= mpic_u3msi_mask_irq,
+	.irq_unmask		= mpic_u3msi_unmask_irq,
+	.irq_eoi		= mpic_end_irq,
+	.irq_set_type		= mpic_set_irq_type,
+	.irq_set_affinity	= mpic_set_affinity,
+	.name			= "MPIC-U3MSI",
+};
+
+static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
+{
+	u8 flags;
+	u32 tmp;
+	u64 addr;
+
+	pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags);
+
+	if (flags & HT_MSI_FLAGS_FIXED)
+		return HT_MSI_FIXED_ADDR;
+
+	pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp);
+	addr = tmp & HT_MSI_ADDR_LO_MASK;
+	pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp);
+	addr = addr | ((u64)tmp << 32);
+
+	return addr;
+}
+
+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->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);
+	}
+
+	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 void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
+{
+	struct msi_desc *entry;
+
+        list_for_each_entry(entry, &pdev->msi_list, list) {
+		if (entry->irq == NO_IRQ)
+			continue;
+
+		irq_set_msi_desc(entry->irq, NULL);
+		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap,
+				       virq_to_hw(entry->irq), 1);
+		irq_dispose_mapping(entry->irq);
+	}
+
+	return;
+}
+
+static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+	unsigned int virq;
+	struct msi_desc *entry;
+	struct msi_msg msg;
+	u64 addr;
+	int hwirq;
+
+	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) == 0 &&
+	    find_u4_magic_addr(pdev, 0) == 0) {
+		pr_debug("u3msi: no magic address found for %s\n",
+			 pci_name(pdev));
+		return -ENXIO;
+	}
+
+	list_for_each_entry(entry, &pdev->msi_list, list) {
+		hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap, 1);
+		if (hwirq < 0) {
+			pr_debug("u3msi: failed allocating hwirq\n");
+			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);
+			msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, 1);
+			return -ENOSPC;
+		}
+
+		irq_set_msi_desc(virq, entry);
+		irq_set_chip(virq, &mpic_u3msi_chip);
+		irq_set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
+
+		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;
+		pci_write_msi_msg(virq, &msg);
+
+		hwirq++;
+	}
+
+	return 0;
+}
+
+int mpic_u3msi_init(struct mpic *mpic)
+{
+	int rc;
+
+	rc = mpic_msi_init_allocator(mpic);
+	if (rc) {
+		pr_debug("u3msi: Error allocating bitmap!\n");
+		return rc;
+	}
+
+	pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n");
+
+	BUG_ON(msi_mpic);
+	msi_mpic = mpic;
+
+	WARN_ON(ppc_md.setup_msi_irqs);
+	ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
+	ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
+
+	return 0;
+}