arch/mips/pci/msi-octeon.c - kernel/prism - Git at Google

 /*
  * 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);
	/*
	* 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);