drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c

Source file repositories/reference/linux-study-clean/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c

File Facts

System
Linux kernel
Corpus path
drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
Extension
.c
Size
4187 bytes
Lines
193
Domain
Driver Families
Bucket
drivers/vfio
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * Copyright 2013-2016 Freescale Semiconductor Inc.
 * Copyright 2019 NXP
 */

#include <linux/vfio.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/eventfd.h>

#include "linux/fsl/mc.h"
#include "vfio_fsl_mc_private.h"

static int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
{
	struct fsl_mc_device *mc_dev = vdev->mc_dev;
	struct vfio_fsl_mc_irq *mc_irq;
	int irq_count;
	int ret, i;

	/* Device does not support any interrupt */
	if (mc_dev->obj_desc.irq_count == 0)
		return 0;

	/* interrupts were already allocated for this device */
	if (vdev->mc_irqs)
		return 0;

	irq_count = mc_dev->obj_desc.irq_count;

	mc_irq = kzalloc_objs(*mc_irq, irq_count, GFP_KERNEL_ACCOUNT);
	if (!mc_irq)
		return -ENOMEM;

	/* Allocate IRQs */
	ret = fsl_mc_allocate_irqs(mc_dev);
	if (ret) {
		kfree(mc_irq);
		return ret;
	}

	for (i = 0; i < irq_count; i++) {
		mc_irq[i].count = 1;
		mc_irq[i].flags = VFIO_IRQ_INFO_EVENTFD;
	}

	vdev->mc_irqs = mc_irq;

	return 0;
}

static irqreturn_t vfio_fsl_mc_irq_handler(int irq_num, void *arg)
{
	struct vfio_fsl_mc_irq *mc_irq = (struct vfio_fsl_mc_irq *)arg;

	eventfd_signal(mc_irq->trigger);
	return IRQ_HANDLED;
}

static int vfio_set_trigger(struct vfio_fsl_mc_device *vdev,
						   int index, int fd)
{
	struct vfio_fsl_mc_irq *irq = &vdev->mc_irqs[index];
	struct eventfd_ctx *trigger;
	int hwirq;
	int ret;

	hwirq = vdev->mc_dev->irqs[index]->virq;
	if (irq->trigger) {
		free_irq(hwirq, irq);
		kfree(irq->name);
		eventfd_ctx_put(irq->trigger);
		irq->trigger = NULL;
	}

	if (fd < 0) /* Disable only */
		return 0;

	irq->name = kasprintf(GFP_KERNEL_ACCOUNT, "vfio-irq[%d](%s)",
			    hwirq, dev_name(&vdev->mc_dev->dev));
	if (!irq->name)
		return -ENOMEM;

	trigger = eventfd_ctx_fdget(fd);
	if (IS_ERR(trigger)) {
		kfree(irq->name);
		return PTR_ERR(trigger);
	}

Annotation

Implementation Notes