powerpc/pasemi: Only the build the pasemi MSI code for PASEMI=y

The pasemi MSI code is currently always built when MPIC=y && PCI_MSI=y.
It should not have any effect on other platforms, because it immediately
checks the MPIC's compatible property for "pasemi,pwrficient-openpic".

However it's odd that it's still built even when PASEMI=n. It also
needn't be in sysdev, as it's only used by pasemi. So move it into
platforms/pasemi, whereby it will only be built for PASEMI=y.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 166 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pasemi/Makefile b/arch/powerpc/platforms/pasemi/Makefile
index 8e8d4cae5ebe..60b4e0fd9808 100644
--- a/arch/powerpc/platforms/pasemi/Makefile
+++ b/arch/powerpc/platforms/pasemi/Makefile
@@ -1,2 +1,3 @@
 obj-y	+= setup.o pci.o time.o idle.o powersave.o iommu.o dma_lib.o misc.o
 obj-$(CONFIG_PPC_PASEMI_MDIO)	+= gpio_mdio.o
+obj-$(CONFIG_PCI_MSI)		+= msi.o
diff --git a/arch/powerpc/platforms/pasemi/msi.c b/arch/powerpc/platforms/pasemi/msi.c
new file mode 100644
index 000000000000..0b3706604543
--- /dev/null
+++ b/arch/powerpc/platforms/pasemi/msi.c
@@ -0,0 +1,165 @@
+/*
+ * Copyright 2007, Olof Johansson, PA Semi
+ *
+ * Based on arch/powerpc/sysdev/mpic_u3msi.c:
+ *
+ * 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 <sysdev/mpic.h>
+
+/* Allocate 16 interrupts per device, to give an alignment of 16,
+ * since that's the size of the grouping w.r.t. affinity. If someone
+ * needs more than 32 MSI's down the road we'll have to rethink this,
+ * but it should be OK for now.
+ */
+#define ALLOC_CHUNK 16
+
+#define PASEMI_MSI_ADDR 0xfc080000
+
+/* A bit ugly, can we get this from the pci_dev somehow? */
+static struct mpic *msi_mpic;
+
+
+static void mpic_pasemi_msi_mask_irq(struct irq_data *data)
+{
+	pr_debug("mpic_pasemi_msi_mask_irq %d\n", data->irq);
+	pci_msi_mask_irq(data);
+	mpic_mask_irq(data);
+}
+
+static void mpic_pasemi_msi_unmask_irq(struct irq_data *data)
+{
+	pr_debug("mpic_pasemi_msi_unmask_irq %d\n", data->irq);
+	mpic_unmask_irq(data);
+	pci_msi_unmask_irq(data);
+}
+
+static struct irq_chip mpic_pasemi_msi_chip = {
+	.irq_shutdown		= mpic_pasemi_msi_mask_irq,
+	.irq_mask		= mpic_pasemi_msi_mask_irq,
+	.irq_unmask		= mpic_pasemi_msi_unmask_irq,
+	.irq_eoi		= mpic_end_irq,
+	.irq_set_type		= mpic_set_irq_type,
+	.irq_set_affinity	= mpic_set_affinity,
+	.name			= "PASEMI-MSI",
+};
+
+static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
+{
+	struct msi_desc *entry;
+
+	pr_debug("pasemi_msi_teardown_msi_irqs, pdev %p\n", pdev);
+
+	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), ALLOC_CHUNK);
+		irq_dispose_mapping(entry->irq);
+	}
+
+	return;
+}
+
+static int pasemi_msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+	unsigned int virq;
+	struct msi_desc *entry;
+	struct msi_msg msg;
+	int hwirq;
+
+	if (type == PCI_CAP_ID_MSIX)
+		pr_debug("pasemi_msi: MSI-X untested, trying anyway\n");
+	pr_debug("pasemi_msi_setup_msi_irqs, pdev %p nvec %d type %d\n",
+		 pdev, nvec, type);
+
+	msg.address_hi = 0;
+	msg.address_lo = PASEMI_MSI_ADDR;
+
+	list_for_each_entry(entry, &pdev->msi_list, list) {
+		/* Allocate 16 interrupts for now, since that's the grouping for
+		 * affinity. This can be changed later if it turns out 32 is too
+		 * few MSIs for someone, but restrictions will apply to how the
+		 * sources can be changed independently.
+		 */
+		hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap,
+						ALLOC_CHUNK);
+		if (hwirq < 0) {
+			pr_debug("pasemi_msi: failed allocating hwirq\n");
+			return hwirq;
+		}
+
+		virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
+		if (virq == NO_IRQ) {
+			pr_debug("pasemi_msi: failed mapping hwirq 0x%x\n",
+				  hwirq);
+			msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq,
+					       ALLOC_CHUNK);
+			return -ENOSPC;
+		}
+
+		/* Vector on MSI is really an offset, the hardware adds
+		 * it to the value written at the magic address. So set
+		 * it to 0 to remain sane.
+		 */
+		mpic_set_vector(virq, 0);
+
+		irq_set_msi_desc(virq, entry);
+		irq_set_chip(virq, &mpic_pasemi_msi_chip);
+		irq_set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
+
+		pr_debug("pasemi_msi: allocated virq 0x%x (hw 0x%x) " \
+			 "addr 0x%x\n", virq, hwirq, msg.address_lo);
+
+		/* Likewise, the device writes [0...511] into the target
+		 * register to generate MSI [512...1023]
+		 */
+		msg.data = hwirq-0x200;
+		pci_write_msi_msg(virq, &msg);
+	}
+
+	return 0;
+}
+
+int mpic_pasemi_msi_init(struct mpic *mpic)
+{
+	int rc;
+
+	if (!mpic->irqhost->of_node ||
+	    !of_device_is_compatible(mpic->irqhost->of_node,
+				     "pasemi,pwrficient-openpic"))
+		return -ENODEV;
+
+	rc = mpic_msi_init_allocator(mpic);
+	if (rc) {
+		pr_debug("pasemi_msi: Error allocating bitmap!\n");
+		return rc;
+	}
+
+	pr_debug("pasemi_msi: Registering PA Semi MPIC MSI callbacks\n");
+
+	msi_mpic = mpic;
+	WARN_ON(ppc_md.setup_msi_irqs);
+	ppc_md.setup_msi_irqs = pasemi_msi_setup_msi_irqs;
+	ppc_md.teardown_msi_irqs = pasemi_msi_teardown_msi_irqs;
+
+	return 0;
+}