1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
4 */
5
6#include <linux/vfio.h>
7#include <linux/slab.h>
8#include <linux/types.h>
9#include <linux/eventfd.h>
10#include <linux/msi.h>
11#include <linux/interrupt.h>
12
13#include "linux/cdx/cdx_bus.h"
14#include "private.h"
15
16static irqreturn_t vfio_cdx_msihandler(int irq_no, void *arg)
17{
18	struct eventfd_ctx *trigger = arg;
19
20	eventfd_signal(trigger);
21	return IRQ_HANDLED;
22}
23
24static int vfio_cdx_msi_enable(struct vfio_cdx_device *vdev, int nvec)
25{
26	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
27	struct device *dev = vdev->vdev.dev;
28	int msi_idx, ret;
29
30	vdev->cdx_irqs = kcalloc(nvec, sizeof(struct vfio_cdx_irq), GFP_KERNEL);
31	if (!vdev->cdx_irqs)
32		return -ENOMEM;
33
34	ret = cdx_enable_msi(cdx_dev);
35	if (ret) {
36		kfree(vdev->cdx_irqs);
37		return ret;
38	}
39
40	/* Allocate cdx MSIs */
41	ret = msi_domain_alloc_irqs(dev, MSI_DEFAULT_DOMAIN, nvec);
42	if (ret) {
43		cdx_disable_msi(cdx_dev);
44		kfree(vdev->cdx_irqs);
45		return ret;
46	}
47
48	for (msi_idx = 0; msi_idx < nvec; msi_idx++)
49		vdev->cdx_irqs[msi_idx].irq_no = msi_get_virq(dev, msi_idx);
50
51	vdev->msi_count = nvec;
52	vdev->config_msi = 1;
53
54	return 0;
55}
56
57static int vfio_cdx_msi_set_vector_signal(struct vfio_cdx_device *vdev,
58					  int vector, int fd)
59{
60	struct eventfd_ctx *trigger;
61	int irq_no, ret;
62
63	if (vector < 0 || vector >= vdev->msi_count)
64		return -EINVAL;
65
66	irq_no = vdev->cdx_irqs[vector].irq_no;
67
68	if (vdev->cdx_irqs[vector].trigger) {
69		free_irq(irq_no, vdev->cdx_irqs[vector].trigger);
70		kfree(vdev->cdx_irqs[vector].name);
71		eventfd_ctx_put(vdev->cdx_irqs[vector].trigger);
72		vdev->cdx_irqs[vector].trigger = NULL;
73	}
74
75	if (fd < 0)
76		return 0;
77
78	vdev->cdx_irqs[vector].name = kasprintf(GFP_KERNEL, "vfio-msi[%d](%s)",
79						vector, dev_name(vdev->vdev.dev));
80	if (!vdev->cdx_irqs[vector].name)
81		return -ENOMEM;
82
83	trigger = eventfd_ctx_fdget(fd);
84	if (IS_ERR(trigger)) {
85		kfree(vdev->cdx_irqs[vector].name);
86		return PTR_ERR(trigger);
87	}
88
89	ret = request_irq(irq_no, vfio_cdx_msihandler, 0,
90			  vdev->cdx_irqs[vector].name, trigger);
91	if (ret) {
92		kfree(vdev->cdx_irqs[vector].name);
93		eventfd_ctx_put(trigger);
94		return ret;
95	}
96
97	vdev->cdx_irqs[vector].trigger = trigger;
98
99	return 0;
100}
101
102static int vfio_cdx_msi_set_block(struct vfio_cdx_device *vdev,
103				  unsigned int start, unsigned int count,
104				  int32_t *fds)
105{
106	int i, j, ret = 0;
107
108	if (start >= vdev->msi_count || start + count > vdev->msi_count)
109		return -EINVAL;
110
111	for (i = 0, j = start; i < count && !ret; i++, j++) {
112		int fd = fds ? fds[i] : -1;
113
114		ret = vfio_cdx_msi_set_vector_signal(vdev, j, fd);
115	}
116
117	if (ret) {
118		for (--j; j >= (int)start; j--)
119			vfio_cdx_msi_set_vector_signal(vdev, j, -1);
120	}
121
122	return ret;
123}
124
125static void vfio_cdx_msi_disable(struct vfio_cdx_device *vdev)
126{
127	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
128	struct device *dev = vdev->vdev.dev;
129
130	vfio_cdx_msi_set_block(vdev, 0, vdev->msi_count, NULL);
131
132	if (!vdev->config_msi)
133		return;
134
135	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
136	cdx_disable_msi(cdx_dev);
137	kfree(vdev->cdx_irqs);
138
139	vdev->cdx_irqs = NULL;
140	vdev->msi_count = 0;
141	vdev->config_msi = 0;
142}
143
144static int vfio_cdx_set_msi_trigger(struct vfio_cdx_device *vdev,
145				    unsigned int index, unsigned int start,
146				    unsigned int count, u32 flags,
147				    void *data)
148{
149	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
150	int i;
151
152	if (start + count > cdx_dev->num_msi)
153		return -EINVAL;
154
155	if (!count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
156		vfio_cdx_msi_disable(vdev);
157		return 0;
158	}
159
160	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
161		s32 *fds = data;
162		int ret;
163
164		if (vdev->config_msi)
165			return vfio_cdx_msi_set_block(vdev, start, count,
166						  fds);
167		ret = vfio_cdx_msi_enable(vdev, cdx_dev->num_msi);
168		if (ret)
169			return ret;
170
171		ret = vfio_cdx_msi_set_block(vdev, start, count, fds);
172		if (ret)
173			vfio_cdx_msi_disable(vdev);
174
175		return ret;
176	}
177
178	for (i = start; i < start + count; i++) {
179		if (!vdev->cdx_irqs[i].trigger)
180			continue;
181		if (flags & VFIO_IRQ_SET_DATA_NONE) {
182			eventfd_signal(vdev->cdx_irqs[i].trigger);
183		} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
184			u8 *bools = data;
185
186			if (bools[i - start])
187				eventfd_signal(vdev->cdx_irqs[i].trigger);
188		}
189	}
190
191	return 0;
192}
193
194int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
195			    u32 flags, unsigned int index,
196			    unsigned int start, unsigned int count,
197			    void *data)
198{
199	if (flags & VFIO_IRQ_SET_ACTION_TRIGGER)
200		return vfio_cdx_set_msi_trigger(vdev, index, start,
201			  count, flags, data);
202	else
203		return -EINVAL;
204}
205
206/* Free All IRQs for the given device */
207void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
208{
209	/*
210	 * Device does not support any interrupt or the interrupts
211	 * were not configured
212	 */
213	if (!vdev->cdx_irqs)
214		return;
215
216	vfio_cdx_set_msi_trigger(vdev, 0, 0, 0, VFIO_IRQ_SET_DATA_NONE, NULL);
217}
218