1 files changed, 436 insertions, 0 deletions
diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c
new file mode 100644
index 000000000..cffaaf4aa
--- /dev/null
+++ b/arch/mips/pci/msi-octeon.c
@@ -0,0 +1,436 @@
+/*
+ * 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, 2010 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-sli-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 u64 msi_free_irq_bitmask[4];
+
+/*
+ * 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 u64 msi_multiple_irq_bitmask[4];
+
+/*
+ * This lock controls updates to msi_free_irq_bitmask and
+ * msi_multiple_irq_bitmask.
+ */
+static DEFINE_SPINLOCK(msi_free_irq_bitmask_lock);
+
+/*
+ * Number of MSI IRQs used. This variable is set up in
+ * the module init time.
+ */
+static int msi_irq_size;
+
+/**
+ * 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;
+	u16 control;
+	int configured_private_bits;
+	int request_private_bits;
+	int irq = 0;
+	int irq_step;
+	u64 search_mask;
+	int index;
+
+	/*
+	 * 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, dev->msi_cap + 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 (index = 0; index < msi_irq_size/64; index++) {
+		for (irq = 0; irq < 64; irq += irq_step) {
+			if ((msi_free_irq_bitmask[index] & (search_mask << irq)) == 0) {
+				msi_free_irq_bitmask[index] |= search_mask << irq;
+				msi_multiple_irq_bitmask[index] |= (search_mask >> 1) << irq;
+				goto msi_irq_allocated;
+			}
+		}
+	}
+msi_irq_allocated:
+	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 += index*64;
+	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;
+		break;
+	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;
+	case OCTEON_DMA_BAR_TYPE_PCIE2:
+		/* When using PCIe2, Bar 0 is based at 0 */
+		msg.address_lo = (0 + CVMX_SLI_PCIE_MSI_RCV) & 0xffffffff;
+		msg.address_hi = (0 + CVMX_SLI_PCIE_MSI_RCV) >> 32;
+		break;
+	default:
+		panic("arch_setup_msi_irq: Invalid octeon_dma_bar_type");
+	}
+	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, dev->msi_cap + PCI_MSI_FLAGS, control);
+
+	irq_set_msi_desc(irq, desc);
+	pci_write_msi_msg(irq, &msg);
+	return 0;
+}
+
+int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	struct msi_desc *entry;
+	int ret;
+
+	/*
+	 * MSI-X is not supported.
+	 */
+	if (type == PCI_CAP_ID_MSIX)
+		return -EINVAL;
+
+	/*
+	 * If an architecture wants to support multiple MSI, it needs to
+	 * override arch_setup_msi_irqs()
+	 */
+	if (type == PCI_CAP_ID_MSI && nvec > 1)
+		return 1;
+
+	list_for_each_entry(entry, &dev->msi_list, list) {
+		ret = arch_setup_msi_irq(dev, entry);
+		if (ret < 0)
+			return ret;
+		if (ret > 0)
+			return -ENOSPC;
+	}
+
+	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;
+	u64 bitmask;
+	int index = 0;
+	int irq0;
+
+	if ((irq < OCTEON_IRQ_MSI_BIT0)
+		|| (irq > msi_irq_size + OCTEON_IRQ_MSI_BIT0))
+		panic("arch_teardown_msi_irq: Attempted to teardown illegal "
+		      "MSI interrupt (%d)", irq);
+
+	irq -= OCTEON_IRQ_MSI_BIT0;
+	index = irq / 64;
+	irq0 = irq % 64;
+
+	/*
+	 * 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 ((irq0 + number_irqs < 64) &&
+	       (msi_multiple_irq_bitmask[index]
+		& (1ull << (irq0 + 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 <<= irq0;
+	if ((msi_free_irq_bitmask[index] & 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[index] &= ~bitmask;
+	msi_multiple_irq_bitmask[index] &= ~bitmask;
+	spin_unlock(&msi_free_irq_bitmask_lock);
+}
+
+static DEFINE_RAW_SPINLOCK(octeon_irq_msi_lock);
+
+static u64 msi_rcv_reg[4];
+static u64 mis_ena_reg[4];
+
+static void octeon_irq_msi_enable_pcie(struct irq_data *data)
+{
+	u64 en;
+	unsigned long flags;
+	int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0;
+	int irq_index = msi_number >> 6;
+	int irq_bit = msi_number & 0x3f;
+
+	raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
+	en = cvmx_read_csr(mis_ena_reg[irq_index]);
+	en |= 1ull << irq_bit;
+	cvmx_write_csr(mis_ena_reg[irq_index], en);
+	cvmx_read_csr(mis_ena_reg[irq_index]);
+	raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
+}
+
+static void octeon_irq_msi_disable_pcie(struct irq_data *data)
+{
+	u64 en;
+	unsigned long flags;
+	int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0;
+	int irq_index = msi_number >> 6;
+	int irq_bit = msi_number & 0x3f;
+
+	raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
+	en = cvmx_read_csr(mis_ena_reg[irq_index]);
+	en &= ~(1ull << irq_bit);
+	cvmx_write_csr(mis_ena_reg[irq_index], en);
+	cvmx_read_csr(mis_ena_reg[irq_index]);
+	raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
+}
+
+static struct irq_chip octeon_irq_chip_msi_pcie = {
+	.name = "MSI",
+	.irq_enable = octeon_irq_msi_enable_pcie,
+	.irq_disable = octeon_irq_msi_disable_pcie,
+};
+
+static void octeon_irq_msi_enable_pci(struct irq_data *data)
+{
+	/*
+	 * Octeon PCI doesn't have the ability to mask/unmask MSI
+	 * interrupts individually. Instead of masking/unmasking them
+	 * in groups of 16, we simple assume MSI devices are well
+	 * behaved. MSI interrupts are always enable and the ACK is
+	 * assumed to be enough
+	 */
+}
+
+static void octeon_irq_msi_disable_pci(struct irq_data *data)
+{
+	/* See comment in enable */
+}
+
+static struct irq_chip octeon_irq_chip_msi_pci = {
+	.name = "MSI",
+	.irq_enable = octeon_irq_msi_enable_pci,
+	.irq_disable = octeon_irq_msi_disable_pci,
+};
+
+/*
+ * Called by the interrupt handling code when an MSI interrupt
+ * occurs.
+ */
+static irqreturn_t __octeon_msi_do_interrupt(int index, u64 msi_bits)
+{
+	int irq;
+	int bit;
+
+	bit = fls64(msi_bits);
+	if (bit) {
+		bit--;
+		/* Acknowledge it first. */
+		cvmx_write_csr(msi_rcv_reg[index], 1ull << bit);
+
+		irq = bit + OCTEON_IRQ_MSI_BIT0 + 64 * index;
+		do_IRQ(irq);
+		return IRQ_HANDLED;
+	}
+	return IRQ_NONE;
+}
+
+#define OCTEON_MSI_INT_HANDLER_X(x)					\
+static irqreturn_t octeon_msi_interrupt##x(int cpl, void *dev_id)	\
+{									\
+	u64 msi_bits = cvmx_read_csr(msi_rcv_reg[(x)]);			\
+	return __octeon_msi_do_interrupt((x), msi_bits);		\
+}
+
+/*
+ * Create octeon_msi_interrupt{0-3} function body
+ */
+OCTEON_MSI_INT_HANDLER_X(0);
+OCTEON_MSI_INT_HANDLER_X(1);
+OCTEON_MSI_INT_HANDLER_X(2);
+OCTEON_MSI_INT_HANDLER_X(3);
+
+/*
+ * Initializes the MSI interrupt handling code
+ */
+int __init octeon_msi_initialize(void)
+{
+	int irq;
+	struct irq_chip *msi;
+
+	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
+		msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
+		msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
+		msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
+		msi_rcv_reg[3] = CVMX_PEXP_NPEI_MSI_RCV3;
+		mis_ena_reg[0] = CVMX_PEXP_NPEI_MSI_ENB0;
+		mis_ena_reg[1] = CVMX_PEXP_NPEI_MSI_ENB1;
+		mis_ena_reg[2] = CVMX_PEXP_NPEI_MSI_ENB2;
+		mis_ena_reg[3] = CVMX_PEXP_NPEI_MSI_ENB3;
+		msi = &octeon_irq_chip_msi_pcie;
+	} else {
+		msi_rcv_reg[0] = CVMX_NPI_NPI_MSI_RCV;
+#define INVALID_GENERATE_ADE 0x8700000000000000ULL;
+		msi_rcv_reg[1] = INVALID_GENERATE_ADE;
+		msi_rcv_reg[2] = INVALID_GENERATE_ADE;
+		msi_rcv_reg[3] = INVALID_GENERATE_ADE;
+		mis_ena_reg[0] = INVALID_GENERATE_ADE;
+		mis_ena_reg[1] = INVALID_GENERATE_ADE;
+		mis_ena_reg[2] = INVALID_GENERATE_ADE;
+		mis_ena_reg[3] = INVALID_GENERATE_ADE;
+		msi = &octeon_irq_chip_msi_pci;
+	}
+
+	for (irq = OCTEON_IRQ_MSI_BIT0; irq <= OCTEON_IRQ_MSI_LAST; irq++)
+		irq_set_chip_and_handler(irq, msi, handle_simple_irq);
+
+	if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
+		if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
+				0, "MSI[0:63]", octeon_msi_interrupt0))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt1,
+				0, "MSI[64:127]", octeon_msi_interrupt1))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt2,
+				0, "MSI[127:191]", octeon_msi_interrupt2))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt3,
+				0, "MSI[192:255]", octeon_msi_interrupt3))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
+
+		msi_irq_size = 256;
+	} else if (octeon_is_pci_host()) {
+		if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
+				0, "MSI[0:15]", octeon_msi_interrupt0))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt0,
+				0, "MSI[16:31]", octeon_msi_interrupt0))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt0,
+				0, "MSI[32:47]", octeon_msi_interrupt0))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
+
+		if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt0,
+				0, "MSI[48:63]", octeon_msi_interrupt0))
+			panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
+		msi_irq_size = 64;
+	}
+	return 0;
+}
+subsys_initcall(octeon_msi_initialize);