tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * VFIO platform devices interrupt handling
3 *
4 * Copyright (C) 2013 - Virtual Open Systems
5 * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License, version 2, as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/eventfd.h>
18#include <linux/interrupt.h>
19#include <linux/slab.h>
20#include <linux/types.h>
21#include <linux/vfio.h>
22#include <linux/irq.h>
23
24#include "vfio_platform_private.h"
25
26static void vfio_platform_mask(struct vfio_platform_irq *irq_ctx)
27{
28 unsigned long flags;
29
30 spin_lock_irqsave(&irq_ctx->lock, flags);
31
32 if (!irq_ctx->masked) {
33 disable_irq_nosync(irq_ctx->hwirq);
34 irq_ctx->masked = true;
35 }
36
37 spin_unlock_irqrestore(&irq_ctx->lock, flags);
38}
39
40static int vfio_platform_mask_handler(void *opaque, void *unused)
41{
42 struct vfio_platform_irq *irq_ctx = opaque;
43
44 vfio_platform_mask(irq_ctx);
45
46 return 0;
47}
48
49static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
50 unsigned index, unsigned start,
51 unsigned count, uint32_t flags,
52 void *data)
53{
54 if (start != 0 || count != 1)
55 return -EINVAL;
56
57 if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
58 return -EINVAL;
59
60 if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
61 int32_t fd = *(int32_t *)data;
62
63 if (fd >= 0)
64 return vfio_virqfd_enable((void *) &vdev->irqs[index],
65 vfio_platform_mask_handler,
66 NULL, NULL,
67 &vdev->irqs[index].mask, fd);
68
69 vfio_virqfd_disable(&vdev->irqs[index].mask);
70 return 0;
71 }
72
73 if (flags & VFIO_IRQ_SET_DATA_NONE) {
74 vfio_platform_mask(&vdev->irqs[index]);
75
76 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
77 uint8_t mask = *(uint8_t *)data;
78
79 if (mask)
80 vfio_platform_mask(&vdev->irqs[index]);
81 }
82
83 return 0;
84}
85
86static void vfio_platform_unmask(struct vfio_platform_irq *irq_ctx)
87{
88 unsigned long flags;
89
90 spin_lock_irqsave(&irq_ctx->lock, flags);
91
92 if (irq_ctx->masked) {
93 enable_irq(irq_ctx->hwirq);
94 irq_ctx->masked = false;
95 }
96
97 spin_unlock_irqrestore(&irq_ctx->lock, flags);
98}
99
100static int vfio_platform_unmask_handler(void *opaque, void *unused)
101{
102 struct vfio_platform_irq *irq_ctx = opaque;
103
104 vfio_platform_unmask(irq_ctx);
105
106 return 0;
107}
108
109static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
110 unsigned index, unsigned start,
111 unsigned count, uint32_t flags,
112 void *data)
113{
114 if (start != 0 || count != 1)
115 return -EINVAL;
116
117 if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
118 return -EINVAL;
119
120 if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
121 int32_t fd = *(int32_t *)data;
122
123 if (fd >= 0)
124 return vfio_virqfd_enable((void *) &vdev->irqs[index],
125 vfio_platform_unmask_handler,
126 NULL, NULL,
127 &vdev->irqs[index].unmask,
128 fd);
129
130 vfio_virqfd_disable(&vdev->irqs[index].unmask);
131 return 0;
132 }
133
134 if (flags & VFIO_IRQ_SET_DATA_NONE) {
135 vfio_platform_unmask(&vdev->irqs[index]);
136
137 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
138 uint8_t unmask = *(uint8_t *)data;
139
140 if (unmask)
141 vfio_platform_unmask(&vdev->irqs[index]);
142 }
143
144 return 0;
145}
146
147static irqreturn_t vfio_automasked_irq_handler(int irq, void *dev_id)
148{
149 struct vfio_platform_irq *irq_ctx = dev_id;
150 unsigned long flags;
151 int ret = IRQ_NONE;
152
153 spin_lock_irqsave(&irq_ctx->lock, flags);
154
155 if (!irq_ctx->masked) {
156 ret = IRQ_HANDLED;
157
158 /* automask maskable interrupts */
159 disable_irq_nosync(irq_ctx->hwirq);
160 irq_ctx->masked = true;
161 }
162
163 spin_unlock_irqrestore(&irq_ctx->lock, flags);
164
165 if (ret == IRQ_HANDLED)
166 eventfd_signal(irq_ctx->trigger, 1);
167
168 return ret;
169}
170
171static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
172{
173 struct vfio_platform_irq *irq_ctx = dev_id;
174
175 eventfd_signal(irq_ctx->trigger, 1);
176
177 return IRQ_HANDLED;
178}
179
180static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
181 int fd, irq_handler_t handler)
182{
183 struct vfio_platform_irq *irq = &vdev->irqs[index];
184 struct eventfd_ctx *trigger;
185 int ret;
186
187 if (irq->trigger) {
188 free_irq(irq->hwirq, irq);
189 kfree(irq->name);
190 eventfd_ctx_put(irq->trigger);
191 irq->trigger = NULL;
192 }
193
194 if (fd < 0) /* Disable only */
195 return 0;
196
197 irq->name = kasprintf(GFP_KERNEL, "vfio-irq[%d](%s)",
198 irq->hwirq, vdev->name);
199 if (!irq->name)
200 return -ENOMEM;
201
202 trigger = eventfd_ctx_fdget(fd);
203 if (IS_ERR(trigger)) {
204 kfree(irq->name);
205 return PTR_ERR(trigger);
206 }
207
208 irq->trigger = trigger;
209
210 irq_set_status_flags(irq->hwirq, IRQ_NOAUTOEN);
211 ret = request_irq(irq->hwirq, handler, 0, irq->name, irq);
212 if (ret) {
213 kfree(irq->name);
214 eventfd_ctx_put(trigger);
215 irq->trigger = NULL;
216 return ret;
217 }
218
219 if (!irq->masked)
220 enable_irq(irq->hwirq);
221
222 return 0;
223}
224
225static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
226 unsigned index, unsigned start,
227 unsigned count, uint32_t flags,
228 void *data)
229{
230 struct vfio_platform_irq *irq = &vdev->irqs[index];
231 irq_handler_t handler;
232
233 if (vdev->irqs[index].flags & VFIO_IRQ_INFO_AUTOMASKED)
234 handler = vfio_automasked_irq_handler;
235 else
236 handler = vfio_irq_handler;
237
238 if (!count && (flags & VFIO_IRQ_SET_DATA_NONE))
239 return vfio_set_trigger(vdev, index, -1, handler);
240
241 if (start != 0 || count != 1)
242 return -EINVAL;
243
244 if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
245 int32_t fd = *(int32_t *)data;
246
247 return vfio_set_trigger(vdev, index, fd, handler);
248 }
249
250 if (flags & VFIO_IRQ_SET_DATA_NONE) {
251 handler(irq->hwirq, irq);
252
253 } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
254 uint8_t trigger = *(uint8_t *)data;
255
256 if (trigger)
257 handler(irq->hwirq, irq);
258 }
259
260 return 0;
261}
262
263int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev,
264 uint32_t flags, unsigned index, unsigned start,
265 unsigned count, void *data)
266{
267 int (*func)(struct vfio_platform_device *vdev, unsigned index,
268 unsigned start, unsigned count, uint32_t flags,
269 void *data) = NULL;
270
271 switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
272 case VFIO_IRQ_SET_ACTION_MASK:
273 func = vfio_platform_set_irq_mask;
274 break;
275 case VFIO_IRQ_SET_ACTION_UNMASK:
276 func = vfio_platform_set_irq_unmask;
277 break;
278 case VFIO_IRQ_SET_ACTION_TRIGGER:
279 func = vfio_platform_set_irq_trigger;
280 break;
281 }
282
283 if (!func)
284 return -ENOTTY;
285
286 return func(vdev, index, start, count, flags, data);
287}
288
289int vfio_platform_irq_init(struct vfio_platform_device *vdev)
290{
291 int cnt = 0, i;
292
293 while (vdev->get_irq(vdev, cnt) >= 0)
294 cnt++;
295
296 vdev->irqs = kcalloc(cnt, sizeof(struct vfio_platform_irq), GFP_KERNEL);
297 if (!vdev->irqs)
298 return -ENOMEM;
299
300 for (i = 0; i < cnt; i++) {
301 int hwirq = vdev->get_irq(vdev, i);
302
303 if (hwirq < 0)
304 goto err;
305
306 spin_lock_init(&vdev->irqs[i].lock);
307
308 vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
309
310 if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
311 vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE
312 | VFIO_IRQ_INFO_AUTOMASKED;
313
314 vdev->irqs[i].count = 1;
315 vdev->irqs[i].hwirq = hwirq;
316 vdev->irqs[i].masked = false;
317 }
318
319 vdev->num_irqs = cnt;
320
321 return 0;
322err:
323 kfree(vdev->irqs);
324 return -EINVAL;
325}
326
327void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev)
328{
329 int i;
330
331 for (i = 0; i < vdev->num_irqs; i++)
332 vfio_set_trigger(vdev, i, -1, NULL);
333
334 vdev->num_irqs = 0;
335 kfree(vdev->irqs);
336}