linux/drivers/vfio/platform/vfio_platform_irq.c

338 lines
7.3 KiB
C

/*
* VFIO platform devices interrupt handling
*
* Copyright (C) 2013 - Virtual Open Systems
* Author: Antonios Motakis <a.motakis@virtualopensystems.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.
*/
#include <linux/eventfd.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vfio.h>
#include <linux/irq.h>
#include "vfio_platform_private.h"
static void vfio_platform_mask(struct vfio_platform_irq *irq_ctx)
{
unsigned long flags;
spin_lock_irqsave(&irq_ctx->lock, flags);
if (!irq_ctx->masked) {
disable_irq_nosync(irq_ctx->hwirq);
irq_ctx->masked = true;
}
spin_unlock_irqrestore(&irq_ctx->lock, flags);
}
static int vfio_platform_mask_handler(void *opaque, void *unused)
{
struct vfio_platform_irq *irq_ctx = opaque;
vfio_platform_mask(irq_ctx);
return 0;
}
static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags,
void *data)
{
if (start != 0 || count != 1)
return -EINVAL;
if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
return -EINVAL;
if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
int32_t fd = *(int32_t *)data;
if (fd >= 0)
return vfio_virqfd_enable((void *) &vdev->irqs[index],
vfio_platform_mask_handler,
NULL, NULL,
&vdev->irqs[index].mask, fd);
vfio_virqfd_disable(&vdev->irqs[index].mask);
return 0;
}
if (flags & VFIO_IRQ_SET_DATA_NONE) {
vfio_platform_mask(&vdev->irqs[index]);
} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
uint8_t mask = *(uint8_t *)data;
if (mask)
vfio_platform_mask(&vdev->irqs[index]);
}
return 0;
}
static void vfio_platform_unmask(struct vfio_platform_irq *irq_ctx)
{
unsigned long flags;
spin_lock_irqsave(&irq_ctx->lock, flags);
if (irq_ctx->masked) {
enable_irq(irq_ctx->hwirq);
irq_ctx->masked = false;
}
spin_unlock_irqrestore(&irq_ctx->lock, flags);
}
static int vfio_platform_unmask_handler(void *opaque, void *unused)
{
struct vfio_platform_irq *irq_ctx = opaque;
vfio_platform_unmask(irq_ctx);
return 0;
}
static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags,
void *data)
{
if (start != 0 || count != 1)
return -EINVAL;
if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
return -EINVAL;
if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
int32_t fd = *(int32_t *)data;
if (fd >= 0)
return vfio_virqfd_enable((void *) &vdev->irqs[index],
vfio_platform_unmask_handler,
NULL, NULL,
&vdev->irqs[index].unmask,
fd);
vfio_virqfd_disable(&vdev->irqs[index].unmask);
return 0;
}
if (flags & VFIO_IRQ_SET_DATA_NONE) {
vfio_platform_unmask(&vdev->irqs[index]);
} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
uint8_t unmask = *(uint8_t *)data;
if (unmask)
vfio_platform_unmask(&vdev->irqs[index]);
}
return 0;
}
static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id)
{
struct vfio_platform_irq *irq_ctx = dev_id;
unsigned long flags;
int ret = IRQ_NONE;
spin_lock_irqsave(&irq_ctx->lock, flags);
if (!irq_ctx->masked) {
ret = IRQ_HANDLED;
/* automask maskable interrupts */
disable_irq_nosync(irq_ctx->hwirq);
irq_ctx->masked = true;
}
spin_unlock_irqrestore(&irq_ctx->lock, flags);
if (ret == IRQ_HANDLED)
eventfd_signal(irq_ctx->trigger, 1);
return ret;
}
static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
{
struct vfio_platform_irq *irq_ctx = dev_id;
eventfd_signal(irq_ctx->trigger, 1);
return IRQ_HANDLED;
}
static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
int fd, irq_handler_t handler)
{
struct vfio_platform_irq *irq = &vdev->irqs[index];
struct eventfd_ctx *trigger;
int ret;
if (irq->trigger) {
irq_clear_status_flags(irq->hwirq, IRQ_NOAUTOEN);
free_irq(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, "vfio-irq[%d](%s)",
irq->hwirq, vdev->name);
if (!irq->name)
return -ENOMEM;
trigger = eventfd_ctx_fdget(fd);
if (IS_ERR(trigger)) {
kfree(irq->name);
return PTR_ERR(trigger);
}
irq->trigger = trigger;
irq_set_status_flags(irq->hwirq, IRQ_NOAUTOEN);
ret = request_irq(irq->hwirq, handler, 0, irq->name, irq);
if (ret) {
kfree(irq->name);
eventfd_ctx_put(trigger);
irq->trigger = NULL;
return ret;
}
if (!irq->masked)
enable_irq(irq->hwirq);
return 0;
}
static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
unsigned index, unsigned start,
unsigned count, uint32_t flags,
void *data)
{
struct vfio_platform_irq *irq = &vdev->irqs[index];
irq_handler_t handler;
if (vdev->irqs[index].flags & VFIO_IRQ_INFO_AUTOMASKED)
handler = vfio_automasked_irq_handler;
else
handler = vfio_irq_handler;
if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
return vfio_set_trigger(vdev, index, -1, handler);
if (start != 0 || count != 1)
return -EINVAL;
if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
int32_t fd = *(int32_t *)data;
return vfio_set_trigger(vdev, index, fd, handler);
}
if (flags & VFIO_IRQ_SET_DATA_NONE) {
handler(irq->hwirq, irq);
} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
uint8_t trigger = *(uint8_t *)data;
if (trigger)
handler(irq->hwirq, irq);
}
return 0;
}
int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
uint32_t flags, unsigned index, unsigned start,
unsigned count, void *data)
{
int (*func)(struct vfio_platform_device *vdev, unsigned index,
unsigned start, unsigned count, uint32_t flags,
void *data) = NULL;
switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
case VFIO_IRQ_SET_ACTION_MASK:
func = vfio_platform_set_irq_mask;
break;
case VFIO_IRQ_SET_ACTION_UNMASK:
func = vfio_platform_set_irq_unmask;
break;
case VFIO_IRQ_SET_ACTION_TRIGGER:
func = vfio_platform_set_irq_trigger;
break;
}
if (!func)
return -ENOTTY;
return func(vdev, index, start, count, flags, data);
}
int vfio_platform_irq_init(struct vfio_platform_device *vdev)
{
int cnt = 0, i;
while (vdev->get_irq(vdev, cnt) >= 0)
cnt++;
vdev->irqs = kcalloc(cnt, sizeof(struct vfio_platform_irq), GFP_KERNEL);
if (!vdev->irqs)
return -ENOMEM;
for (i = 0; i < cnt; i++) {
int hwirq = vdev->get_irq(vdev, i);
if (hwirq < 0)
goto err;
spin_lock_init(&vdev->irqs[i].lock);
vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE
| VFIO_IRQ_INFO_AUTOMASKED;
vdev->irqs[i].count = 1;
vdev->irqs[i].hwirq = hwirq;
vdev->irqs[i].masked = false;
}
vdev->num_irqs = cnt;
return 0;
err:
kfree(vdev->irqs);
return -EINVAL;
}
void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
{
int i;
for (i = 0; i < vdev->num_irqs; i++)
vfio_set_trigger(vdev, i, -1, NULL);
vdev->num_irqs = 0;
kfree(vdev->irqs);
}