1 files changed, 288 insertions, 0 deletions
diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c
new file mode 100644
index 00000000000..03742e64765
--- /dev/null
+++ b/arch/mips/pci/msi-octeon.c
@@ -0,0 +1,288 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2005-2009 Cavium Networks
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/msi.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/octeon/cvmx-npi-defs.h>
+#include <asm/octeon/cvmx-pci-defs.h>
+#include <asm/octeon/cvmx-npei-defs.h>
+#include <asm/octeon/cvmx-pexp-defs.h>
+#include <asm/octeon/pci-octeon.h>
+
+/*
+ * Each bit in msi_free_irq_bitmask represents a MSI interrupt that is
+ * in use.
+ */
+static uint64_t msi_free_irq_bitmask;
+
+/*
+ * Each bit in msi_multiple_irq_bitmask tells that the device using
+ * this bit in msi_free_irq_bitmask is also using the next bit. This
+ * is used so we can disable all of the MSI interrupts when a device
+ * uses multiple.
+ */
+static uint64_t msi_multiple_irq_bitmask;
+
+/*
+ * This lock controls updates to msi_free_irq_bitmask and
+ * msi_multiple_irq_bitmask.
+ */
+static DEFINE_SPINLOCK(msi_free_irq_bitmask_lock);
+
+
+/**
+ * Called when a driver request MSI interrupts instead of the
+ * legacy INT A-D. This routine will allocate multiple interrupts
+ * for MSI devices that support them. A device can override this by
+ * programming the MSI control bits [6:4] before calling
+ * pci_enable_msi().
+ *
+ * @dev:    Device requesting MSI interrupts
+ * @desc:   MSI descriptor
+ *
+ * Returns 0 on success.
+ */
+int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
+{
+	struct msi_msg msg;
+	uint16_t control;
+	int configured_private_bits;
+	int request_private_bits;
+	int irq;
+	int irq_step;
+	uint64_t search_mask;
+
+	/*
+	 * Read the MSI config to figure out how many IRQs this device
+	 * wants.  Most devices only want 1, which will give
+	 * configured_private_bits and request_private_bits equal 0.
+	 */
+	pci_read_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
+			     &control);
+
+	/*
+	 * If the number of private bits has been configured then use
+	 * that value instead of the requested number. This gives the
+	 * driver the chance to override the number of interrupts
+	 * before calling pci_enable_msi().
+	 */
+	configured_private_bits = (control & PCI_MSI_FLAGS_QSIZE) >> 4;
+	if (configured_private_bits == 0) {
+		/* Nothing is configured, so use the hardware requested size */
+		request_private_bits = (control & PCI_MSI_FLAGS_QMASK) >> 1;
+	} else {
+		/*
+		 * Use the number of configured bits, assuming the
+		 * driver wanted to override the hardware request
+		 * value.
+		 */
+		request_private_bits = configured_private_bits;
+	}
+
+	/*
+	 * The PCI 2.3 spec mandates that there are at most 32
+	 * interrupts. If this device asks for more, only give it one.
+	 */
+	if (request_private_bits > 5)
+		request_private_bits = 0;
+
+try_only_one:
+	/*
+	 * The IRQs have to be aligned on a power of two based on the
+	 * number being requested.
+	 */
+	irq_step = 1 << request_private_bits;
+
+	/* Mask with one bit for each IRQ */
+	search_mask = (1 << irq_step) - 1;
+
+	/*
+	 * We're going to search msi_free_irq_bitmask_lock for zero
+	 * bits. This represents an MSI interrupt number that isn't in
+	 * use.
+	 */
+	spin_lock(&msi_free_irq_bitmask_lock);
+	for (irq = 0; irq < 64; irq += irq_step) {
+		if ((msi_free_irq_bitmask & (search_mask << irq)) == 0) {
+			msi_free_irq_bitmask |= search_mask << irq;
+			msi_multiple_irq_bitmask |= (search_mask >> 1) << irq;
+			break;
+		}
+	}
+	spin_unlock(&msi_free_irq_bitmask_lock);
+
+	/* Make sure the search for available interrupts didn't fail */
+	if (irq >= 64) {
+		if (request_private_bits) {
+			pr_err("arch_setup_msi_irq: Unable to find %d free "
+			       "interrupts, trying just one",
+			       1 << request_private_bits);
+			request_private_bits = 0;
+			goto try_only_one;
+		} else
+			panic("arch_setup_msi_irq: Unable to find a free MSI "
+			      "interrupt");
+	}
+
+	/* MSI interrupts start at logical IRQ OCTEON_IRQ_MSI_BIT0 */
+	irq += OCTEON_IRQ_MSI_BIT0;
+
+	switch (octeon_dma_bar_type) {
+	case OCTEON_DMA_BAR_TYPE_SMALL:
+		/* When not using big bar, Bar 0 is based at 128MB */
+		msg.address_lo =
+			((128ul << 20) + CVMX_PCI_MSI_RCV) & 0xffffffff;
+		msg.address_hi = ((128ul << 20) + CVMX_PCI_MSI_RCV) >> 32;
+	case OCTEON_DMA_BAR_TYPE_BIG:
+		/* When using big bar, Bar 0 is based at 0 */
+		msg.address_lo = (0 + CVMX_PCI_MSI_RCV) & 0xffffffff;
+		msg.address_hi = (0 + CVMX_PCI_MSI_RCV) >> 32;
+		break;
+	case OCTEON_DMA_BAR_TYPE_PCIE:
+		/* When using PCIe, Bar 0 is based at 0 */
+		/* FIXME CVMX_NPEI_MSI_RCV* other than 0? */
+		msg.address_lo = (0 + CVMX_NPEI_PCIE_MSI_RCV) & 0xffffffff;
+		msg.address_hi = (0 + CVMX_NPEI_PCIE_MSI_RCV) >> 32;
+		break;
+	default:
+		panic("arch_setup_msi_irq: Invalid octeon_dma_bar_type\n");
+	}
+	msg.data = irq - OCTEON_IRQ_MSI_BIT0;
+
+	/* Update the number of IRQs the device has available to it */
+	control &= ~PCI_MSI_FLAGS_QSIZE;
+	control |= request_private_bits << 4;
+	pci_write_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
+			      control);
+
+	set_irq_msi(irq, desc);
+	write_msi_msg(irq, &msg);
+	return 0;
+}
+
+
+/**
+ * Called when a device no longer needs its MSI interrupts. All
+ * MSI interrupts for the device are freed.
+ *
+ * @irq:    The devices first irq number. There may be multple in sequence.
+ */
+void arch_teardown_msi_irq(unsigned int irq)
+{
+	int number_irqs;
+	uint64_t bitmask;
+
+	if ((irq < OCTEON_IRQ_MSI_BIT0) || (irq > OCTEON_IRQ_MSI_BIT63))
+		panic("arch_teardown_msi_irq: Attempted to teardown illegal "
+		      "MSI interrupt (%d)", irq);
+	irq -= OCTEON_IRQ_MSI_BIT0;
+
+	/*
+	 * Count the number of IRQs we need to free by looking at the
+	 * msi_multiple_irq_bitmask. Each bit set means that the next
+	 * IRQ is also owned by this device.
+	 */
+	number_irqs = 0;
+	while ((irq+number_irqs < 64) &&
+	       (msi_multiple_irq_bitmask & (1ull << (irq + number_irqs))))
+		number_irqs++;
+	number_irqs++;
+	/* Mask with one bit for each IRQ */
+	bitmask = (1 << number_irqs) - 1;
+	/* Shift the mask to the correct bit location */
+	bitmask <<= irq;
+	if ((msi_free_irq_bitmask & bitmask) != bitmask)
+		panic("arch_teardown_msi_irq: Attempted to teardown MSI "
+		      "interrupt (%d) not in use", irq);
+
+	/* Checks are done, update the in use bitmask */
+	spin_lock(&msi_free_irq_bitmask_lock);
+	msi_free_irq_bitmask &= ~bitmask;
+	msi_multiple_irq_bitmask &= ~bitmask;
+	spin_unlock(&msi_free_irq_bitmask_lock);
+}
+
+
+/*
+ * Called by the interrupt handling code when an MSI interrupt
+ * occurs.
+ */
+static irqreturn_t octeon_msi_interrupt(int cpl, void *dev_id)
+{
+	uint64_t msi_bits;
+	int irq;
+
+	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE)
+		msi_bits = cvmx_read_csr(CVMX_PEXP_NPEI_MSI_RCV0);
+	else
+		msi_bits = cvmx_read_csr(CVMX_NPI_NPI_MSI_RCV);
+	irq = fls64(msi_bits);
+	if (irq) {
+		irq += OCTEON_IRQ_MSI_BIT0 - 1;
+		if (irq_desc[irq].action) {
+			do_IRQ(irq);
+			return IRQ_HANDLED;
+		} else {
+			pr_err("Spurious MSI interrupt %d\n", irq);
+			if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
+				/* These chips have PCIe */
+				cvmx_write_csr(CVMX_PEXP_NPEI_MSI_RCV0,
+					       1ull << (irq -
+							OCTEON_IRQ_MSI_BIT0));
+			} else {
+				/* These chips have PCI */
+				cvmx_write_csr(CVMX_NPI_NPI_MSI_RCV,
+					       1ull << (irq -
+							OCTEON_IRQ_MSI_BIT0));
+			}
+		}
+	}
+	return IRQ_NONE;
+}
+
+
+/*
+ * Initializes the MSI interrupt handling code
+ */
+int octeon_msi_initialize(void)
+{
+	if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
+		if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt,
+				IRQF_SHARED,
+				"MSI[0:63]", octeon_msi_interrupt))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
+	} else if (octeon_is_pci_host()) {
+		if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt,
+				IRQF_SHARED,
+				"MSI[0:15]", octeon_msi_interrupt))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt,
+				IRQF_SHARED,
+				"MSI[16:31]", octeon_msi_interrupt))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt,
+				IRQF_SHARED,
+				"MSI[32:47]", octeon_msi_interrupt))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt,
+				IRQF_SHARED,
+				"MSI[48:63]", octeon_msi_interrupt))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
+
+	}
+	return 0;
+}
+
+subsys_initcall(octeon_msi_initialize);