[mirror_ubuntu-bionic-kernel.git] / drivers / pci / host / pcie-altera-msi.c

/*
 * Altera PCIe MSI support
 *
 * Author: Ley Foon Tan <lftan@altera.com>
 *
 * Copyright Altera Corporation (C) 2013-2015. All rights reserved
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/interrupt.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/init.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#define MSI_STATUS		0x0
#define MSI_ERROR		0x4
#define MSI_INTMASK		0x8

#define MAX_MSI_VECTORS		32

struct altera_msi {
	DECLARE_BITMAP(used, MAX_MSI_VECTORS);
	struct mutex		lock;	/* protect "used" bitmap */
	struct platform_device	*pdev;
	struct irq_domain	*msi_domain;
	struct irq_domain	*inner_domain;
	void __iomem		*csr_base;
	void __iomem		*vector_base;
	phys_addr_t		vector_phy;
	u32			num_of_vectors;
	int			irq;
};

static inline void msi_writel(struct altera_msi *msi, const u32 value,
			      const u32 reg)
{
	writel_relaxed(value, msi->csr_base + reg);
}

static inline u32 msi_readl(struct altera_msi *msi, const u32 reg)
{
	return readl_relaxed(msi->csr_base + reg);
}

static void altera_msi_isr(struct irq_desc *desc)
{
	struct irq_chip *chip = irq_desc_get_chip(desc);
	struct altera_msi *msi;
	unsigned long status;
	u32 bit;
	u32 virq;

	chained_irq_enter(chip, desc);
	msi = irq_desc_get_handler_data(desc);

	while ((status = msi_readl(msi, MSI_STATUS)) != 0) {
		for_each_set_bit(bit, &status, msi->num_of_vectors) {
			/* Dummy read from vector to clear the interrupt */
			readl_relaxed(msi->vector_base + (bit * sizeof(u32)));

			virq = irq_find_mapping(msi->inner_domain, bit);
			if (virq)
				generic_handle_irq(virq);
			else
				dev_err(&msi->pdev->dev, "unexpected MSI\n");
		}
	}

	chained_irq_exit(chip, desc);
}

static struct irq_chip altera_msi_irq_chip = {
	.name = "Altera PCIe MSI",
	.irq_mask = pci_msi_mask_irq,
	.irq_unmask = pci_msi_unmask_irq,
};

static struct msi_domain_info altera_msi_domain_info = {
	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
		     MSI_FLAG_PCI_MSIX),
	.chip	= &altera_msi_irq_chip,
};

static void altera_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
	struct altera_msi *msi = irq_data_get_irq_chip_data(data);
	phys_addr_t addr = msi->vector_phy + (data->hwirq * sizeof(u32));

	msg->address_lo = lower_32_bits(addr);
	msg->address_hi = upper_32_bits(addr);
	msg->data = data->hwirq;

	dev_dbg(&msi->pdev->dev, "msi#%d address_hi %#x address_lo %#x\n",
		(int)data->hwirq, msg->address_hi, msg->address_lo);
}

static int altera_msi_set_affinity(struct irq_data *irq_data,
				   const struct cpumask *mask, bool force)
{
	 return -EINVAL;
}

static struct irq_chip altera_msi_bottom_irq_chip = {
	.name			= "Altera MSI",
	.irq_compose_msi_msg	= altera_compose_msi_msg,
	.irq_set_affinity	= altera_msi_set_affinity,
};

static int altera_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
				   unsigned int nr_irqs, void *args)
{
	struct altera_msi *msi = domain->host_data;
	unsigned long bit;
	u32 mask;

	WARN_ON(nr_irqs != 1);
	mutex_lock(&msi->lock);

	bit = find_first_zero_bit(msi->used, msi->num_of_vectors);
	if (bit >= msi->num_of_vectors) {
		mutex_unlock(&msi->lock);
		return -ENOSPC;
	}

	set_bit(bit, msi->used);

	mutex_unlock(&msi->lock);

	irq_domain_set_info(domain, virq, bit, &altera_msi_bottom_irq_chip,
			    domain->host_data, handle_simple_irq,
			    NULL, NULL);

	mask = msi_readl(msi, MSI_INTMASK);
	mask |= 1 << bit;
	msi_writel(msi, mask, MSI_INTMASK);

	return 0;
}

static void altera_irq_domain_free(struct irq_domain *domain,
				   unsigned int virq, unsigned int nr_irqs)
{
	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
	struct altera_msi *msi = irq_data_get_irq_chip_data(d);
	u32 mask;

	mutex_lock(&msi->lock);

	if (!test_bit(d->hwirq, msi->used)) {
		dev_err(&msi->pdev->dev, "trying to free unused MSI#%lu\n",
			d->hwirq);
	} else {
		__clear_bit(d->hwirq, msi->used);
		mask = msi_readl(msi, MSI_INTMASK);
		mask &= ~(1 << d->hwirq);
		msi_writel(msi, mask, MSI_INTMASK);
	}

	mutex_unlock(&msi->lock);
}

static const struct irq_domain_ops msi_domain_ops = {
	.alloc	= altera_irq_domain_alloc,
	.free	= altera_irq_domain_free,
};

static int altera_allocate_domains(struct altera_msi *msi)
{
	struct fwnode_handle *fwnode = of_node_to_fwnode(msi->pdev->dev.of_node);

	msi->inner_domain = irq_domain_add_linear(NULL, msi->num_of_vectors,
					     &msi_domain_ops, msi);
	if (!msi->inner_domain) {
		dev_err(&msi->pdev->dev, "failed to create IRQ domain\n");
		return -ENOMEM;
	}

	msi->msi_domain = pci_msi_create_irq_domain(fwnode,
				&altera_msi_domain_info, msi->inner_domain);
	if (!msi->msi_domain) {
		dev_err(&msi->pdev->dev, "failed to create MSI domain\n");
		irq_domain_remove(msi->inner_domain);
		return -ENOMEM;
	}

	return 0;
}

static void altera_free_domains(struct altera_msi *msi)
{
	irq_domain_remove(msi->msi_domain);
	irq_domain_remove(msi->inner_domain);
}

static int altera_msi_remove(struct platform_device *pdev)
{
	struct altera_msi *msi = platform_get_drvdata(pdev);

	msi_writel(msi, 0, MSI_INTMASK);
	irq_set_chained_handler(msi->irq, NULL);
	irq_set_handler_data(msi->irq, NULL);

	altera_free_domains(msi);

	platform_set_drvdata(pdev, NULL);
	return 0;
}

static int altera_msi_probe(struct platform_device *pdev)
{
	struct altera_msi *msi;
	struct device_node *np = pdev->dev.of_node;
	struct resource *res;
	int ret;

	msi = devm_kzalloc(&pdev->dev, sizeof(struct altera_msi),
			   GFP_KERNEL);
	if (!msi)
		return -ENOMEM;

	mutex_init(&msi->lock);
	msi->pdev = pdev;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
	msi->csr_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(msi->csr_base)) {
		dev_err(&pdev->dev, "failed to map csr memory\n");
		return PTR_ERR(msi->csr_base);
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
					   "vector_slave");
	msi->vector_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(msi->vector_base)) {
		dev_err(&pdev->dev, "failed to map vector_slave memory\n");
		return PTR_ERR(msi->vector_base);
	}

	msi->vector_phy = res->start;

	if (of_property_read_u32(np, "num-vectors", &msi->num_of_vectors)) {
		dev_err(&pdev->dev, "failed to parse the number of vectors\n");
		return -EINVAL;
	}

	ret = altera_allocate_domains(msi);
	if (ret)
		return ret;

	msi->irq = platform_get_irq(pdev, 0);
	if (msi->irq < 0) {
		dev_err(&pdev->dev, "failed to map IRQ: %d\n", msi->irq);
		ret = msi->irq;
		goto err;
	}

	irq_set_chained_handler_and_data(msi->irq, altera_msi_isr, msi);
	platform_set_drvdata(pdev, msi);

	return 0;

err:
	altera_msi_remove(pdev);
	return ret;
}

static const struct of_device_id altera_msi_of_match[] = {
	{ .compatible = "altr,msi-1.0", NULL },
	{ },
};

static struct platform_driver altera_msi_driver = {
	.driver = {
		.name = "altera-msi",
		.of_match_table = altera_msi_of_match,
	},
	.probe = altera_msi_probe,
	.remove = altera_msi_remove,
};

static int __init altera_msi_init(void)
{
	return platform_driver_register(&altera_msi_driver);
}
subsys_initcall(altera_msi_init);
Commit	Line	Data
af1169b4	1	/*
18224b3a PG	2	* Altera PCIe MSI support
	3	*
	4	* Author: Ley Foon Tan <lftan@altera.com>
	5	*
af1169b4 LFT	6	* Copyright Altera Corporation (C) 2013-2015. All rights reserved
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms and conditions of the GNU General Public License,
	10	* version 2, as published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope it will be useful, but WITHOUT
	13	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	14	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	15	* more details.
	16	*
	17	* You should have received a copy of the GNU General Public License along with
	18	* this program. If not, see <http://www.gnu.org/licenses/>.
	19	*/
	20
	21	#include <linux/interrupt.h>
	22	#include <linux/irqchip/chained_irq.h>
18224b3a	23	#include <linux/init.h>
af1169b4 LFT	24	#include <linux/msi.h>
	25	#include <linux/of_address.h>
	26	#include <linux/of_irq.h>
	27	#include <linux/of_pci.h>
	28	#include <linux/pci.h>
	29	#include <linux/platform_device.h>
	30	#include <linux/slab.h>
	31
	32	#define MSI_STATUS 0x0
	33	#define MSI_ERROR 0x4
	34	#define MSI_INTMASK 0x8
	35
	36	#define MAX_MSI_VECTORS 32
	37
	38	struct altera_msi {
	39	DECLARE_BITMAP(used, MAX_MSI_VECTORS);
	40	struct mutex lock; /* protect "used" bitmap */
	41	struct platform_device *pdev;
	42	struct irq_domain *msi_domain;
	43	struct irq_domain *inner_domain;
	44	void __iomem *csr_base;
	45	void __iomem *vector_base;
	46	phys_addr_t vector_phy;
	47	u32 num_of_vectors;
	48	int irq;
	49	};
	50
	51	static inline void msi_writel(struct altera_msi *msi, const u32 value,
	52	const u32 reg)
	53	{
	54	writel_relaxed(value, msi->csr_base + reg);
	55	}
	56
	57	static inline u32 msi_readl(struct altera_msi *msi, const u32 reg)
	58	{
	59	return readl_relaxed(msi->csr_base + reg);
	60	}
	61
	62	static void altera_msi_isr(struct irq_desc *desc)
	63	{
	64	struct irq_chip *chip = irq_desc_get_chip(desc);
	65	struct altera_msi *msi;
	66	unsigned long status;
af1169b4 LFT	67	u32 bit;
	68	u32 virq;
	69
	70	chained_irq_enter(chip, desc);
	71	msi = irq_desc_get_handler_data(desc);
af1169b4 LFT	72
	73	while ((status = msi_readl(msi, MSI_STATUS)) != 0) {
	74	for_each_set_bit(bit, &status, msi->num_of_vectors) {
	75	/* Dummy read from vector to clear the interrupt */
	76	readl_relaxed(msi->vector_base + (bit * sizeof(u32)));
	77
	78	virq = irq_find_mapping(msi->inner_domain, bit);
	79	if (virq)
	80	generic_handle_irq(virq);
	81	else
	82	dev_err(&msi->pdev->dev, "unexpected MSI\n");
	83	}
	84	}
	85
	86	chained_irq_exit(chip, desc);
	87	}
	88
	89	static struct irq_chip altera_msi_irq_chip = {
	90	.name = "Altera PCIe MSI",
	91	.irq_mask = pci_msi_mask_irq,
	92	.irq_unmask = pci_msi_unmask_irq,
	93	};
	94
	95	static struct msi_domain_info altera_msi_domain_info = {
	96	.flags = (MSI_FLAG_USE_DEF_DOM_OPS \| MSI_FLAG_USE_DEF_CHIP_OPS \|
	97	MSI_FLAG_PCI_MSIX),
	98	.chip = &altera_msi_irq_chip,
	99	};
	100
	101	static void altera_compose_msi_msg(struct irq_data data, struct msi_msg msg)
	102	{
	103	struct altera_msi *msi = irq_data_get_irq_chip_data(data);
	104	phys_addr_t addr = msi->vector_phy + (data->hwirq * sizeof(u32));
	105
	106	msg->address_lo = lower_32_bits(addr);
	107	msg->address_hi = upper_32_bits(addr);
	108	msg->data = data->hwirq;
	109
	110	dev_dbg(&msi->pdev->dev, "msi#%d address_hi %#x address_lo %#x\n",
	111	(int)data->hwirq, msg->address_hi, msg->address_lo);
	112	}
	113
	114	static int altera_msi_set_affinity(struct irq_data *irq_data,
	115	const struct cpumask *mask, bool force)
	116	{
	117	return -EINVAL;
	118	}
	119
	120	static struct irq_chip altera_msi_bottom_irq_chip = {
	121	.name = "Altera MSI",
	122	.irq_compose_msi_msg = altera_compose_msi_msg,
	123	.irq_set_affinity = altera_msi_set_affinity,
	124	};
	125
	126	static int altera_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
	127	unsigned int nr_irqs, void *args)
	128	{
	129	struct altera_msi *msi = domain->host_data;
	130	unsigned long bit;
	131	u32 mask;
	132
	133	WARN_ON(nr_irqs != 1);
	134	mutex_lock(&msi->lock);
	135
136	bit = find_first_zero_bit(msi->used, msi->num_of_vectors);
137	if (bit >= msi->num_of_vectors) {
138	mutex_unlock(&msi->lock);
139	return -ENOSPC;
140	}
141
142	set_bit(bit, msi->used);
143
144	mutex_unlock(&msi->lock);
145
146	irq_domain_set_info(domain, virq, bit, &altera_msi_bottom_irq_chip,
147	domain->host_data, handle_simple_irq,
148	NULL, NULL);
149
150	mask = msi_readl(msi, MSI_INTMASK);
151	mask \|= 1 << bit;
152	msi_writel(msi, mask, MSI_INTMASK);
153
154	return 0;
155	}
156
157	static void altera_irq_domain_free(struct irq_domain *domain,
158	unsigned int virq, unsigned int nr_irqs)
159	{
160	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
161	struct altera_msi *msi = irq_data_get_irq_chip_data(d);
162	u32 mask;
163
164	mutex_lock(&msi->lock);
165
166	if (!test_bit(d->hwirq, msi->used)) {
167	dev_err(&msi->pdev->dev, "trying to free unused MSI#%lu\n",
168	d->hwirq);
169	} else {
170	__clear_bit(d->hwirq, msi->used);
171	mask = msi_readl(msi, MSI_INTMASK);
172	mask &= ~(1 << d->hwirq);
173	msi_writel(msi, mask, MSI_INTMASK);
174	}
175
176	mutex_unlock(&msi->lock);
177	}
178
179	static const struct irq_domain_ops msi_domain_ops = {
180	.alloc = altera_irq_domain_alloc,
181	.free = altera_irq_domain_free,
182	};
183
184	static int altera_allocate_domains(struct altera_msi *msi)
185	{
3c87b791 LT	186	struct fwnode_handle *fwnode = of_node_to_fwnode(msi->pdev->dev.of_node);
3c87b791 LT	187
af1169b4 LFT	188	msi->inner_domain = irq_domain_add_linear(NULL, msi->num_of_vectors,
	189	&msi_domain_ops, msi);
	190	if (!msi->inner_domain) {
	191	dev_err(&msi->pdev->dev, "failed to create IRQ domain\n");
	192	return -ENOMEM;
	193	}
	194
3c87b791	195	msi->msi_domain = pci_msi_create_irq_domain(fwnode,
af1169b4 LFT	196	&altera_msi_domain_info, msi->inner_domain);
	197	if (!msi->msi_domain) {
	198	dev_err(&msi->pdev->dev, "failed to create MSI domain\n");
	199	irq_domain_remove(msi->inner_domain);
	200	return -ENOMEM;
	201	}
	202
	203	return 0;
	204	}
	205
	206	static void altera_free_domains(struct altera_msi *msi)
	207	{
	208	irq_domain_remove(msi->msi_domain);
	209	irq_domain_remove(msi->inner_domain);
	210	}
	211
	212	static int altera_msi_remove(struct platform_device *pdev)
	213	{
	214	struct altera_msi *msi = platform_get_drvdata(pdev);
	215
	216	msi_writel(msi, 0, MSI_INTMASK);
	217	irq_set_chained_handler(msi->irq, NULL);
	218	irq_set_handler_data(msi->irq, NULL);
	219
	220	altera_free_domains(msi);
	221
	222	platform_set_drvdata(pdev, NULL);
	223	return 0;
	224	}
	225
	226	static int altera_msi_probe(struct platform_device *pdev)
	227	{
	228	struct altera_msi *msi;
	229	struct device_node *np = pdev->dev.of_node;
	230	struct resource *res;
	231	int ret;
	232
	233	msi = devm_kzalloc(&pdev->dev, sizeof(struct altera_msi),
	234	GFP_KERNEL);
	235	if (!msi)
	236	return -ENOMEM;
	237
	238	mutex_init(&msi->lock);
	239	msi->pdev = pdev;
	240
	241	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
af1169b4 LFT	242	msi->csr_base = devm_ioremap_resource(&pdev->dev, res);
	243	if (IS_ERR(msi->csr_base)) {
	244	dev_err(&pdev->dev, "failed to map csr memory\n");
	245	return PTR_ERR(msi->csr_base);
	246	}
	247
	248	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
	249	"vector_slave");
af1169b4 LFT	250	msi->vector_base = devm_ioremap_resource(&pdev->dev, res);
	251	if (IS_ERR(msi->vector_base)) {
	252	dev_err(&pdev->dev, "failed to map vector_slave memory\n");
	253	return PTR_ERR(msi->vector_base);
	254	}
	255
	256	msi->vector_phy = res->start;
	257
	258	if (of_property_read_u32(np, "num-vectors", &msi->num_of_vectors)) {
	259	dev_err(&pdev->dev, "failed to parse the number of vectors\n");
	260	return -EINVAL;
	261	}
	262
	263	ret = altera_allocate_domains(msi);
	264	if (ret)
	265	return ret;
	266
	267	msi->irq = platform_get_irq(pdev, 0);
ef75369a	268	if (msi->irq < 0) {
af1169b4	269	dev_err(&pdev->dev, "failed to map IRQ: %d\n", msi->irq);
ef75369a	270	ret = msi->irq;
af1169b4 LFT	271	goto err;
	272	}
	273
	274	irq_set_chained_handler_and_data(msi->irq, altera_msi_isr, msi);
	275	platform_set_drvdata(pdev, msi);
	276
	277	return 0;
	278
	279	err:
	280	altera_msi_remove(pdev);
	281	return ret;
	282	}
	283
	284	static const struct of_device_id altera_msi_of_match[] = {
	285	{ .compatible = "altr,msi-1.0", NULL },
	286	{ },
	287	};
	288
	289	static struct platform_driver altera_msi_driver = {
	290	.driver = {
	291	.name = "altera-msi",
	292	.of_match_table = altera_msi_of_match,
	293	},
	294	.probe = altera_msi_probe,
	295	.remove = altera_msi_remove,
	296	};
	297
	298	static int __init altera_msi_init(void)
	299	{
	300	return platform_driver_register(&altera_msi_driver);
	301	}
	302	subsys_initcall(altera_msi_init);