drivers/irqchip/irq-gic-msi.c - arm/linux-arm-legacy - Git at Google

 /*
  * GIC MSI Extensions Driver.
  *
  * This driver provides support for up to 1 MSI per pci_dev. The functionality
  * is provided by an MSI widget which provides an MSI capture register which
  * fires SPIs. This driver hooks into the standard MSI arch callbacks and maps
  * MSI vectors to SPI interrupts.
  *
  * Copyright (C) 2012-2013 ARM Ltd.
  * Author: Andrew Murray <andrew.murray@arm.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */

 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/irqchip/arm-gic-msi.h>
 #include <linux/module.h>
 #include <linux/msi.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/pci.h>
 #include <linux/slab.h>

 #define DEVICE_NAME "gic-msi"

 #ifdef CONFIG_PCI_MSI

 /* The kernel only supports a single MSI controller, thus our driver is limited
    to a single instance */
 static struct gic_msi_data *gd;

 int arch_setup_msi_irq(struct pci_dev *pdev, struct msi_desc *desc)
 {
 	int virt, vector;
 	struct msi_msg msg;
 	struct gic_msi_frame *frame;

 	if (WARN(!gd, DEVICE_NAME ": No MSI handler"))
 		return 1;

 	/* Look in all the frames to find an available MSI vector/SPI */
 	list_for_each_entry(frame, &gd->frames, list) {
 again:
 		vector = find_first_zero_bit(frame->msi_irq_in_use,
 				frame->nr_msi);
 		if (vector >= frame->nr_msi)
 			continue;

 		if (test_and_set_bit(vector, frame->msi_irq_in_use))
 			goto again;

 		virt = vector + frame->start_spi;

 		irq_set_msi_desc(virt, desc);
 		irq_set_irq_type(virt, IRQ_TYPE_EDGE_RISING);

 #ifdef CONFIG_64BIT
 		msg.address_hi = (phys_addr_t)frame->base_p >> 32;
 #endif
 		msg.address_lo = (phys_addr_t)frame->base_p + GIC_MSI_SETSPI_NSR;
 		msg.data = virt;

 		write_msi_msg(virt, &msg);

 		return 0;
 	}

 	/* No free MSIs */
 	WARN_ON(DEVICE_NAME ": Unable to assign another MSI");
 	return 1;
 }

 void arch_teardown_msi_irq(unsigned int irq)
 {
 	struct gic_msi_frame *frame;
 	int hwirq;

 	if (WARN(!gd, DEVICE_NAME ": No MSI handler"))
 		return;

 	list_for_each_entry(frame, &gd->frames, list) {
 		hwirq = irq - frame->start_spi;
 		if (hwirq < frame->nr_msi) {
 			clear_bit(hwirq, frame->msi_irq_in_use);
 			return;
 		}
 	}
 }
 static int gic_msi_init_frame(struct resource *res)
 {
 	struct gic_msi_frame *frame;
 	int err, x;

 	frame = kzalloc(sizeof(struct gic_msi_frame), GFP_KERNEL);
 	if (WARN(!frame, DEVICE_NAME ": Unable to allocate memory"))
 		return -ENOMEM;

 	frame->base_p = res->start;
 	frame->base_sz = resource_size(res);

 	if (!request_mem_region(res->start, resource_size(res), DEVICE_NAME)) {
 		pr_err(DEVICE_NAME
 			": Failed to request config registers resource\n");
 		err = -EBUSY;
 		goto err_request_mem;
 	}

 	frame->base_p= res->start;
 	frame->base_sz= resource_size(res);
 	frame->base = ioremap(res->start, resource_size(res));
 	if (!frame->base) {
 		pr_err(DEVICE_NAME
 			": Failed to map configuration registers resource\n");
 		err = -ENOMEM;
 		goto err_ioremap;
 	}

 	x = readl(frame->base + GIC_MSI_TYPER);
 	frame->start_spi = (x & GIC_MSI_TYPER_START_MASK)
 				>> GIC_MSI_TYPER_START_SHIFT;
 	frame->nr_msi = x & GIC_MSI_TYPER_NR_MASK;

 	list_add_tail(&frame->list, &gd->frames);

 	return 0;

 err_ioremap:
 	iounmap(frame->base);

 err_request_mem:
 	kfree(frame);

 	return err;
 }

 static int gic_msi_remove_frames(void)
 {
 	struct gic_msi_frame *frame, *tmp;

 	list_for_each_entry_safe(frame, tmp, &gd->frames, list) {
 		iounmap(frame->base);
 		release_mem_region(frame->base_p, frame->base_sz);
 		list_del(&frame->list);
 		kfree(frame);
 	}
 	return 0;
 }

 static int gic_msi_get_virt_offset(struct device_node *np, int *virt_offset)
 {
 	struct device_node *p;
 	struct irq_domain *domain;
 	unsigned int type, spec[3] = { 0, 0, 0 };
 	irq_hw_number_t hwirq;
 	int err;

 	p = of_irq_find_parent(np);
 	if (WARN(!p, DEVICE_NAME ": Unable to find interrupt parent"))
 		return -EINVAL;

 	domain = irq_find_host(p);
 	if (WARN(!domain, DEVICE_NAME
 			": Unable to find interrupt parent domain"))
 		goto err;

 	if (WARN(!domain->ops->xlate, DEVICE_NAME
 		": Unable to translate interrupt parent domain"))
 		goto err;

 	err = domain->ops->xlate(domain, p, spec, sizeof(spec) / sizeof(int),
 					&hwirq, &type);
 	if (err) {
 		pr_err(DEVICE_NAME
 			": Unable to translate interrupt parent domain\n");
 		goto err;

 	}

 	*virt_offset = irq_create_mapping(domain, hwirq);

 	of_node_put(p);
 	return 0;

 err:
 	of_node_put(p);
 	return -EINVAL;
 }

 static int gic_msi_probe(struct platform_device *pdev)
 {
 	int err, x = 0;
 	struct device_node *np;
 	struct resource res;

 	np = pdev->dev.of_node;

 	if (WARN(gd, DEVICE_NAME ": MSI handler already installed"))
 		return -EEXIST;

 	if (WARN(!np, DEVICE_NAME ": No device tree node"))
 		return -EINVAL;

 	gd = kzalloc(sizeof(struct gic_msi_data), GFP_KERNEL);
 	if (WARN(!gd, DEVICE_NAME ": Unable to allocate memory"))
 		return -ENOMEM;

 	INIT_LIST_HEAD(&gd->frames);

 	err = gic_msi_get_virt_offset(np, &gd->virt_offset);
 	if (err) {
 		pr_err(DEVICE_NAME
 			": Unable to get virtual offset\n");
 		goto err_init_frame;
 	}

 	/* Iterate through each frame identified in the DT */
 	while (!(err = of_address_to_resource(np, x++, &res))) {
 		err = gic_msi_init_frame(&res);
 		if (err)
 			goto err_init_frame;

 		break;
 	}

 	return 0;
 err_init_frame:
 	gic_msi_remove_frames();

 	kfree(gd);
 	gd = NULL;

 	return -EINVAL;
 }

 /**
  * Remove is a bad idea. We cannot easily tell PCIe devices to stop
  * sending MSI's they've been allocated. In any case remove is unlikely
  * to be used.
  */
 static int gic_msi_remove(struct platform_device *pdev)
 {
 	gic_msi_remove_frames();

 	kfree(gd);
 	gd = NULL;

 	return 0;
 }

 static const struct of_device_id gic_msi_ids[] = {
 	{ .compatible = "arm,gic-msi", },
 };

 static struct platform_driver gic_msi_driver = {
 	.probe  = gic_msi_probe,
 	.remove = gic_msi_remove,
 	.driver = {
 		.name = DEVICE_NAME,
 		.owner = THIS_MODULE,
 		.of_match_table = gic_msi_ids,
 	},
 };

 static int __init gic_msi_init(void)
 {
 	return platform_driver_register(&gic_msi_driver);
 }

 subsys_initcall(gic_msi_init);
 #endif
	/*
	* GIC MSI Extensions Driver.
	*
	* This driver provides support for up to 1 MSI per pci_dev. The functionality
	* is provided by an MSI widget which provides an MSI capture register which
	* fires SPIs. This driver hooks into the standard MSI arch callbacks and maps
	* MSI vectors to SPI interrupts.
	*
	* Copyright (C) 2012-2013 ARM Ltd.
	* Author: Andrew Murray <andrew.murray@arm.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/io.h>
	#include <linux/irq.h>
	#include <linux/irqchip/arm-gic-msi.h>
	#include <linux/module.h>
	#include <linux/msi.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/of_platform.h>
	#include <linux/pci.h>
	#include <linux/slab.h>

	#define DEVICE_NAME "gic-msi"

	#ifdef CONFIG_PCI_MSI

	/* The kernel only supports a single MSI controller, thus our driver is limited
	to a single instance */
	static struct gic_msi_data *gd;

	int arch_setup_msi_irq(struct pci_dev pdev, struct msi_desc desc)
	{
	int virt, vector;
	struct msi_msg msg;
	struct gic_msi_frame *frame;

	if (WARN(!gd, DEVICE_NAME ": No MSI handler"))
	return 1;

	/* Look in all the frames to find an available MSI vector/SPI */
	list_for_each_entry(frame, &gd->frames, list) {
	again:
	vector = find_first_zero_bit(frame->msi_irq_in_use,
	frame->nr_msi);
	if (vector >= frame->nr_msi)
	continue;

	if (test_and_set_bit(vector, frame->msi_irq_in_use))
	goto again;

	virt = vector + frame->start_spi;

	irq_set_msi_desc(virt, desc);
	irq_set_irq_type(virt, IRQ_TYPE_EDGE_RISING);

	#ifdef CONFIG_64BIT
	msg.address_hi = (phys_addr_t)frame->base_p >> 32;
	#endif
	msg.address_lo = (phys_addr_t)frame->base_p + GIC_MSI_SETSPI_NSR;
	msg.data = virt;

	write_msi_msg(virt, &msg);

	return 0;
	}

	/* No free MSIs */
	WARN_ON(DEVICE_NAME ": Unable to assign another MSI");
	return 1;
	}

	void arch_teardown_msi_irq(unsigned int irq)
	{
	struct gic_msi_frame *frame;
	int hwirq;

	if (WARN(!gd, DEVICE_NAME ": No MSI handler"))
	return;

	list_for_each_entry(frame, &gd->frames, list) {
	hwirq = irq - frame->start_spi;
	if (hwirq < frame->nr_msi) {
	clear_bit(hwirq, frame->msi_irq_in_use);
	return;
	}
	}
	}
	static int gic_msi_init_frame(struct resource *res)
	{
	struct gic_msi_frame *frame;
	int err, x;

	frame = kzalloc(sizeof(struct gic_msi_frame), GFP_KERNEL);
	if (WARN(!frame, DEVICE_NAME ": Unable to allocate memory"))
	return -ENOMEM;

	frame->base_p = res->start;
	frame->base_sz = resource_size(res);

	if (!request_mem_region(res->start, resource_size(res), DEVICE_NAME)) {
	pr_err(DEVICE_NAME
	": Failed to request config registers resource\n");
	err = -EBUSY;
	goto err_request_mem;
	}

	frame->base_p= res->start;
	frame->base_sz= resource_size(res);
	frame->base = ioremap(res->start, resource_size(res));
	if (!frame->base) {
	pr_err(DEVICE_NAME
	": Failed to map configuration registers resource\n");
	err = -ENOMEM;
	goto err_ioremap;
	}

	x = readl(frame->base + GIC_MSI_TYPER);
	frame->start_spi = (x & GIC_MSI_TYPER_START_MASK)
	>> GIC_MSI_TYPER_START_SHIFT;
	frame->nr_msi = x & GIC_MSI_TYPER_NR_MASK;

	list_add_tail(&frame->list, &gd->frames);

	return 0;

	err_ioremap:
	iounmap(frame->base);

	err_request_mem:
	kfree(frame);

	return err;
	}

	static int gic_msi_remove_frames(void)
	{
	struct gic_msi_frame frame, tmp;

	list_for_each_entry_safe(frame, tmp, &gd->frames, list) {
	iounmap(frame->base);
	release_mem_region(frame->base_p, frame->base_sz);
	list_del(&frame->list);
	kfree(frame);
	}
	return 0;
	}

	static int gic_msi_get_virt_offset(struct device_node np, int virt_offset)
	{
	struct device_node *p;
	struct irq_domain *domain;
	unsigned int type, spec[3] = { 0, 0, 0 };
	irq_hw_number_t hwirq;
	int err;

	p = of_irq_find_parent(np);
	if (WARN(!p, DEVICE_NAME ": Unable to find interrupt parent"))
	return -EINVAL;

	domain = irq_find_host(p);
	if (WARN(!domain, DEVICE_NAME
	": Unable to find interrupt parent domain"))
	goto err;

	if (WARN(!domain->ops->xlate, DEVICE_NAME
	": Unable to translate interrupt parent domain"))
	goto err;

	err = domain->ops->xlate(domain, p, spec, sizeof(spec) / sizeof(int),
	&hwirq, &type);
	if (err) {
	pr_err(DEVICE_NAME
	": Unable to translate interrupt parent domain\n");
	goto err;

	}

	*virt_offset = irq_create_mapping(domain, hwirq);

	of_node_put(p);
	return 0;

	err:
	of_node_put(p);
	return -EINVAL;
	}

	static int gic_msi_probe(struct platform_device *pdev)
	{
	int err, x = 0;
	struct device_node *np;
	struct resource res;

	np = pdev->dev.of_node;

	if (WARN(gd, DEVICE_NAME ": MSI handler already installed"))
	return -EEXIST;

	if (WARN(!np, DEVICE_NAME ": No device tree node"))
	return -EINVAL;

	gd = kzalloc(sizeof(struct gic_msi_data), GFP_KERNEL);
	if (WARN(!gd, DEVICE_NAME ": Unable to allocate memory"))
	return -ENOMEM;

	INIT_LIST_HEAD(&gd->frames);

	err = gic_msi_get_virt_offset(np, &gd->virt_offset);
	if (err) {
	pr_err(DEVICE_NAME
	": Unable to get virtual offset\n");
	goto err_init_frame;
	}

	/* Iterate through each frame identified in the DT */
	while (!(err = of_address_to_resource(np, x++, &res))) {
	err = gic_msi_init_frame(&res);
	if (err)
	goto err_init_frame;

	break;
	}

	return 0;
	err_init_frame:
	gic_msi_remove_frames();

	kfree(gd);
	gd = NULL;

	return -EINVAL;
	}

	/**
	* Remove is a bad idea. We cannot easily tell PCIe devices to stop
	* sending MSI's they've been allocated. In any case remove is unlikely
	* to be used.
	*/
	static int gic_msi_remove(struct platform_device *pdev)
	{
	gic_msi_remove_frames();

	kfree(gd);
	gd = NULL;

	return 0;
	}

	static const struct of_device_id gic_msi_ids[] = {
	{ .compatible = "arm,gic-msi", },
	};

	static struct platform_driver gic_msi_driver = {
	.probe = gic_msi_probe,
	.remove = gic_msi_remove,
	.driver = {
	.name = DEVICE_NAME,
	.owner = THIS_MODULE,
	.of_match_table = gic_msi_ids,
	},
	};

	static int __init gic_msi_init(void)
	{
	return platform_driver_register(&gic_msi_driver);
	}

	subsys_initcall(gic_msi_init);
	#endif