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}