Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 = kzalloc_objs(struct vfio_cdx_irq, nvec);
31 if (!vdev->cdx_irqs)
32 return -ENOMEM;
33
34 ret = cdx_enable_msi(cdx_dev);
35 if (ret)
36 goto err_free;
37
38 /* Allocate cdx MSIs */
39 ret = msi_domain_alloc_irqs(dev, MSI_DEFAULT_DOMAIN, nvec);
40 if (ret)
41 goto err_disable;
42
43 for (msi_idx = 0; msi_idx < nvec; msi_idx++)
44 vdev->cdx_irqs[msi_idx].irq_no = msi_get_virq(dev, msi_idx);
45
46 vdev->msi_count = nvec;
47
48 return 0;
49
50err_disable:
51 cdx_disable_msi(cdx_dev);
52err_free:
53 kfree(vdev->cdx_irqs);
54 vdev->cdx_irqs = NULL;
55 return ret;
56}
57
58static int vfio_cdx_msi_set_vector_signal(struct vfio_cdx_device *vdev,
59 int vector, int fd)
60{
61 struct eventfd_ctx *trigger;
62 int irq_no, ret;
63
64 if (vector < 0 || vector >= vdev->msi_count)
65 return -EINVAL;
66
67 irq_no = vdev->cdx_irqs[vector].irq_no;
68
69 if (vdev->cdx_irqs[vector].trigger) {
70 free_irq(irq_no, vdev->cdx_irqs[vector].trigger);
71 kfree(vdev->cdx_irqs[vector].name);
72 eventfd_ctx_put(vdev->cdx_irqs[vector].trigger);
73 vdev->cdx_irqs[vector].trigger = NULL;
74 }
75
76 if (fd < 0)
77 return 0;
78
79 vdev->cdx_irqs[vector].name = kasprintf(GFP_KERNEL, "vfio-msi[%d](%s)",
80 vector, dev_name(vdev->vdev.dev));
81 if (!vdev->cdx_irqs[vector].name)
82 return -ENOMEM;
83
84 trigger = eventfd_ctx_fdget(fd);
85 if (IS_ERR(trigger)) {
86 kfree(vdev->cdx_irqs[vector].name);
87 return PTR_ERR(trigger);
88 }
89
90 ret = request_irq(irq_no, vfio_cdx_msihandler, 0,
91 vdev->cdx_irqs[vector].name, trigger);
92 if (ret) {
93 kfree(vdev->cdx_irqs[vector].name);
94 eventfd_ctx_put(trigger);
95 return ret;
96 }
97
98 vdev->cdx_irqs[vector].trigger = trigger;
99
100 return 0;
101}
102
103static int vfio_cdx_msi_set_block(struct vfio_cdx_device *vdev,
104 unsigned int start, unsigned int count,
105 int32_t *fds)
106{
107 int i, j, ret = 0;
108
109 if (start >= vdev->msi_count || start + count > vdev->msi_count)
110 return -EINVAL;
111
112 for (i = 0, j = start; i < count && !ret; i++, j++) {
113 int fd = fds ? fds[i] : -1;
114
115 ret = vfio_cdx_msi_set_vector_signal(vdev, j, fd);
116 }
117
118 if (ret) {
119 for (--j; j >= (int)start; j--)
120 vfio_cdx_msi_set_vector_signal(vdev, j, -1);
121 }
122
123 return ret;
124}
125
126static void vfio_cdx_msi_disable(struct vfio_cdx_device *vdev)
127{
128 struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
129 struct device *dev = vdev->vdev.dev;
130
131 vfio_cdx_msi_set_block(vdev, 0, vdev->msi_count, NULL);
132
133 if (!vdev->cdx_irqs)
134 return;
135
136 msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
137 cdx_disable_msi(cdx_dev);
138 kfree(vdev->cdx_irqs);
139
140 vdev->cdx_irqs = NULL;
141 vdev->msi_count = 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 guard(mutex)(&vdev->cdx_irqs_lock);
156
157 if (!count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
158 vfio_cdx_msi_disable(vdev);
159 return 0;
160 }
161
162 if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
163 s32 *fds = data;
164 int ret;
165
166 if (vdev->cdx_irqs)
167 return vfio_cdx_msi_set_block(vdev, start, count,
168 fds);
169 ret = vfio_cdx_msi_enable(vdev, cdx_dev->num_msi);
170 if (ret)
171 return ret;
172
173 ret = vfio_cdx_msi_set_block(vdev, start, count, fds);
174 if (ret)
175 vfio_cdx_msi_disable(vdev);
176
177 return ret;
178 }
179
180 if (!vdev->cdx_irqs)
181 return -EINVAL;
182
183 for (i = start; i < start + count; i++) {
184 if (!vdev->cdx_irqs[i].trigger)
185 continue;
186 if (flags & VFIO_IRQ_SET_DATA_NONE) {
187 eventfd_signal(vdev->cdx_irqs[i].trigger);
188 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
189 u8 *bools = data;
190
191 if (bools[i - start])
192 eventfd_signal(vdev->cdx_irqs[i].trigger);
193 }
194 }
195
196 return 0;
197}
198
199int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
200 u32 flags, unsigned int index,
201 unsigned int start, unsigned int count,
202 void *data)
203{
204 if (flags & VFIO_IRQ_SET_ACTION_TRIGGER)
205 return vfio_cdx_set_msi_trigger(vdev, index, start,
206 count, flags, data);
207 else
208 return -EINVAL;
209}
210
211/* Free All IRQs for the given device */
212void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
213{
214 vfio_cdx_set_msi_trigger(vdev, 0, 0, 0, VFIO_IRQ_SET_DATA_NONE, NULL);
215}