1// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
2/*
3 * Copyright 2013-2016 Freescale Semiconductor Inc.
4 * Copyright 2019 NXP
5 */
6
7#include <linux/vfio.h>
8#include <linux/slab.h>
9#include <linux/types.h>
10#include <linux/eventfd.h>
11
12#include "linux/fsl/mc.h"
13#include "vfio_fsl_mc_private.h"
14
15static int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
16{
17	struct fsl_mc_device *mc_dev = vdev->mc_dev;
18	struct vfio_fsl_mc_irq *mc_irq;
19	int irq_count;
20	int ret, i;
21
22	/* Device does not support any interrupt */
23	if (mc_dev->obj_desc.irq_count == 0)
24		return 0;
25
26	/* interrupts were already allocated for this device */
27	if (vdev->mc_irqs)
28		return 0;
29
30	irq_count = mc_dev->obj_desc.irq_count;
31
32	mc_irq = kcalloc(irq_count, sizeof(*mc_irq), GFP_KERNEL_ACCOUNT);
33	if (!mc_irq)
34		return -ENOMEM;
35
36	/* Allocate IRQs */
37	ret = fsl_mc_allocate_irqs(mc_dev);
38	if (ret) {
39		kfree(mc_irq);
40		return ret;
41	}
42
43	for (i = 0; i < irq_count; i++) {
44		mc_irq[i].count = 1;
45		mc_irq[i].flags = VFIO_IRQ_INFO_EVENTFD;
46	}
47
48	vdev->mc_irqs = mc_irq;
49
50	return 0;
51}
52
53static irqreturn_t vfio_fsl_mc_irq_handler(int irq_num, void *arg)
54{
55	struct vfio_fsl_mc_irq *mc_irq = (struct vfio_fsl_mc_irq *)arg;
56
57	eventfd_signal(mc_irq->trigger);
58	return IRQ_HANDLED;
59}
60
61static int vfio_set_trigger(struct vfio_fsl_mc_device *vdev,
62						   int index, int fd)
63{
64	struct vfio_fsl_mc_irq *irq = &vdev->mc_irqs[index];
65	struct eventfd_ctx *trigger;
66	int hwirq;
67	int ret;
68
69	hwirq = vdev->mc_dev->irqs[index]->virq;
70	if (irq->trigger) {
71		free_irq(hwirq, irq);
72		kfree(irq->name);
73		eventfd_ctx_put(irq->trigger);
74		irq->trigger = NULL;
75	}
76
77	if (fd < 0) /* Disable only */
78		return 0;
79
80	irq->name = kasprintf(GFP_KERNEL_ACCOUNT, "vfio-irq[%d](%s)",
81			    hwirq, dev_name(&vdev->mc_dev->dev));
82	if (!irq->name)
83		return -ENOMEM;
84
85	trigger = eventfd_ctx_fdget(fd);
86	if (IS_ERR(trigger)) {
87		kfree(irq->name);
88		return PTR_ERR(trigger);
89	}
90
91	irq->trigger = trigger;
92
93	ret = request_irq(hwirq, vfio_fsl_mc_irq_handler, 0,
94		  irq->name, irq);
95	if (ret) {
96		kfree(irq->name);
97		eventfd_ctx_put(trigger);
98		irq->trigger = NULL;
99		return ret;
100	}
101
102	return 0;
103}
104
105static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
106				       unsigned int index, unsigned int start,
107				       unsigned int count, u32 flags,
108				       void *data)
109{
110	struct fsl_mc_device *mc_dev = vdev->mc_dev;
111	int ret, hwirq;
112	struct vfio_fsl_mc_irq *irq;
113	struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
114	struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
115
116	if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
117		return vfio_set_trigger(vdev, index, -1);
118
119	if (start != 0 || count != 1)
120		return -EINVAL;
121
122	mutex_lock(&vdev->vdev.dev_set->lock);
123	ret = fsl_mc_populate_irq_pool(mc_cont,
124			FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS);
125	if (ret)
126		goto unlock;
127
128	ret = vfio_fsl_mc_irqs_allocate(vdev);
129	if (ret)
130		goto unlock;
131	mutex_unlock(&vdev->vdev.dev_set->lock);
132
133	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
134		s32 fd = *(s32 *)data;
135
136		return vfio_set_trigger(vdev, index, fd);
137	}
138
139	hwirq = vdev->mc_dev->irqs[index]->virq;
140
141	irq = &vdev->mc_irqs[index];
142
143	if (flags & VFIO_IRQ_SET_DATA_NONE) {
144		if (irq->trigger)
145			eventfd_signal(irq->trigger);
146
147	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
148		u8 trigger = *(u8 *)data;
149
150		if (trigger && irq->trigger)
151			eventfd_signal(irq->trigger);
152	}
153
154	return 0;
155
156unlock:
157	mutex_unlock(&vdev->vdev.dev_set->lock);
158	return ret;
159
160}
161
162int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
163			       u32 flags, unsigned int index,
164			       unsigned int start, unsigned int count,
165			       void *data)
166{
167	if (flags & VFIO_IRQ_SET_ACTION_TRIGGER)
168		return  vfio_fsl_mc_set_irq_trigger(vdev, index, start,
169			  count, flags, data);
170	else
171		return -EINVAL;
172}
173
174/* Free All IRQs for the given MC object */
175void vfio_fsl_mc_irqs_cleanup(struct vfio_fsl_mc_device *vdev)
176{
177	struct fsl_mc_device *mc_dev = vdev->mc_dev;
178	int irq_count = mc_dev->obj_desc.irq_count;
179	int i;
180
181	/*
182	 * Device does not support any interrupt or the interrupts
183	 * were not configured
184	 */
185	if (!vdev->mc_irqs)
186		return;
187
188	for (i = 0; i < irq_count; i++)
189		vfio_set_trigger(vdev, i, -1);
190
191	fsl_mc_free_irqs(mc_dev);
192	kfree(vdev->mc_irqs);
193	vdev->mc_irqs = NULL;
194}
195