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/cdx/cdx_bus.h>
8
9#include "private.h"
10
11static int vfio_cdx_open_device(struct vfio_device *core_vdev)
12{
13	struct vfio_cdx_device *vdev =
14		container_of(core_vdev, struct vfio_cdx_device, vdev);
15	struct cdx_device *cdx_dev = to_cdx_device(core_vdev->dev);
16	int count = cdx_dev->res_count;
17	int i, ret;
18
19	vdev->regions = kcalloc(count, sizeof(struct vfio_cdx_region),
20				GFP_KERNEL_ACCOUNT);
21	if (!vdev->regions)
22		return -ENOMEM;
23
24	for (i = 0; i < count; i++) {
25		struct resource *res = &cdx_dev->res[i];
26
27		vdev->regions[i].addr = res->start;
28		vdev->regions[i].size = resource_size(res);
29		vdev->regions[i].type = res->flags;
30		/*
31		 * Only regions addressed with PAGE granularity may be
32		 * MMAP'ed securely.
33		 */
34		if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
35		    !(vdev->regions[i].size & ~PAGE_MASK))
36			vdev->regions[i].flags |=
37					VFIO_REGION_INFO_FLAG_MMAP;
38		vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
39		if (!(cdx_dev->res[i].flags & IORESOURCE_READONLY))
40			vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_WRITE;
41	}
42	ret = cdx_dev_reset(core_vdev->dev);
43	if (ret) {
44		kfree(vdev->regions);
45		vdev->regions = NULL;
46		return ret;
47	}
48	ret = cdx_clear_master(cdx_dev);
49	if (ret)
50		vdev->flags &= ~BME_SUPPORT;
51	else
52		vdev->flags |= BME_SUPPORT;
53
54	return 0;
55}
56
57static void vfio_cdx_close_device(struct vfio_device *core_vdev)
58{
59	struct vfio_cdx_device *vdev =
60		container_of(core_vdev, struct vfio_cdx_device, vdev);
61
62	kfree(vdev->regions);
63	cdx_dev_reset(core_vdev->dev);
64}
65
66static int vfio_cdx_bm_ctrl(struct vfio_device *core_vdev, u32 flags,
67			    void __user *arg, size_t argsz)
68{
69	size_t minsz =
70		offsetofend(struct vfio_device_feature_bus_master, op);
71	struct vfio_cdx_device *vdev =
72		container_of(core_vdev, struct vfio_cdx_device, vdev);
73	struct cdx_device *cdx_dev = to_cdx_device(core_vdev->dev);
74	struct vfio_device_feature_bus_master ops;
75	int ret;
76
77	if (!(vdev->flags & BME_SUPPORT))
78		return -ENOTTY;
79
80	ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET,
81				 sizeof(ops));
82	if (ret != 1)
83		return ret;
84
85	if (copy_from_user(&ops, arg, minsz))
86		return -EFAULT;
87
88	switch (ops.op) {
89	case VFIO_DEVICE_FEATURE_CLEAR_MASTER:
90		return cdx_clear_master(cdx_dev);
91	case VFIO_DEVICE_FEATURE_SET_MASTER:
92		return cdx_set_master(cdx_dev);
93	default:
94		return -EINVAL;
95	}
96}
97
98static int vfio_cdx_ioctl_feature(struct vfio_device *device, u32 flags,
99				  void __user *arg, size_t argsz)
100{
101	switch (flags & VFIO_DEVICE_FEATURE_MASK) {
102	case VFIO_DEVICE_FEATURE_BUS_MASTER:
103		return vfio_cdx_bm_ctrl(device, flags, arg, argsz);
104	default:
105		return -ENOTTY;
106	}
107}
108
109static int vfio_cdx_ioctl_get_info(struct vfio_cdx_device *vdev,
110				   struct vfio_device_info __user *arg)
111{
112	unsigned long minsz = offsetofend(struct vfio_device_info, num_irqs);
113	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
114	struct vfio_device_info info;
115
116	if (copy_from_user(&info, arg, minsz))
117		return -EFAULT;
118
119	if (info.argsz < minsz)
120		return -EINVAL;
121
122	info.flags = VFIO_DEVICE_FLAGS_CDX;
123	info.flags |= VFIO_DEVICE_FLAGS_RESET;
124
125	info.num_regions = cdx_dev->res_count;
126	info.num_irqs = 0;
127
128	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
129}
130
131static int vfio_cdx_ioctl_get_region_info(struct vfio_cdx_device *vdev,
132					  struct vfio_region_info __user *arg)
133{
134	unsigned long minsz = offsetofend(struct vfio_region_info, offset);
135	struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
136	struct vfio_region_info info;
137
138	if (copy_from_user(&info, arg, minsz))
139		return -EFAULT;
140
141	if (info.argsz < minsz)
142		return -EINVAL;
143
144	if (info.index >= cdx_dev->res_count)
145		return -EINVAL;
146
147	/* map offset to the physical address */
148	info.offset = vfio_cdx_index_to_offset(info.index);
149	info.size = vdev->regions[info.index].size;
150	info.flags = vdev->regions[info.index].flags;
151
152	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
153}
154
155static long vfio_cdx_ioctl(struct vfio_device *core_vdev,
156			   unsigned int cmd, unsigned long arg)
157{
158	struct vfio_cdx_device *vdev =
159		container_of(core_vdev, struct vfio_cdx_device, vdev);
160	void __user *uarg = (void __user *)arg;
161
162	switch (cmd) {
163	case VFIO_DEVICE_GET_INFO:
164		return vfio_cdx_ioctl_get_info(vdev, uarg);
165	case VFIO_DEVICE_GET_REGION_INFO:
166		return vfio_cdx_ioctl_get_region_info(vdev, uarg);
167	case VFIO_DEVICE_RESET:
168		return cdx_dev_reset(core_vdev->dev);
169	default:
170		return -ENOTTY;
171	}
172}
173
174static int vfio_cdx_mmap_mmio(struct vfio_cdx_region region,
175			      struct vm_area_struct *vma)
176{
177	u64 size = vma->vm_end - vma->vm_start;
178	u64 pgoff, base;
179
180	pgoff = vma->vm_pgoff &
181		((1U << (VFIO_CDX_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
182	base = pgoff << PAGE_SHIFT;
183
184	if (base + size > region.size)
185		return -EINVAL;
186
187	vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
188	vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
189
190	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
191				  size, vma->vm_page_prot);
192}
193
194static int vfio_cdx_mmap(struct vfio_device *core_vdev,
195			 struct vm_area_struct *vma)
196{
197	struct vfio_cdx_device *vdev =
198		container_of(core_vdev, struct vfio_cdx_device, vdev);
199	struct cdx_device *cdx_dev = to_cdx_device(core_vdev->dev);
200	unsigned int index;
201
202	index = vma->vm_pgoff >> (VFIO_CDX_OFFSET_SHIFT - PAGE_SHIFT);
203
204	if (index >= cdx_dev->res_count)
205		return -EINVAL;
206
207	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
208		return -EINVAL;
209
210	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) &&
211	    (vma->vm_flags & VM_READ))
212		return -EPERM;
213
214	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) &&
215	    (vma->vm_flags & VM_WRITE))
216		return -EPERM;
217
218	return vfio_cdx_mmap_mmio(vdev->regions[index], vma);
219}
220
221static const struct vfio_device_ops vfio_cdx_ops = {
222	.name		= "vfio-cdx",
223	.open_device	= vfio_cdx_open_device,
224	.close_device	= vfio_cdx_close_device,
225	.ioctl		= vfio_cdx_ioctl,
226	.device_feature = vfio_cdx_ioctl_feature,
227	.mmap		= vfio_cdx_mmap,
228	.bind_iommufd	= vfio_iommufd_physical_bind,
229	.unbind_iommufd	= vfio_iommufd_physical_unbind,
230	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
231};
232
233static int vfio_cdx_probe(struct cdx_device *cdx_dev)
234{
235	struct vfio_cdx_device *vdev;
236	struct device *dev = &cdx_dev->dev;
237	int ret;
238
239	vdev = vfio_alloc_device(vfio_cdx_device, vdev, dev,
240				 &vfio_cdx_ops);
241	if (IS_ERR(vdev))
242		return PTR_ERR(vdev);
243
244	ret = vfio_register_group_dev(&vdev->vdev);
245	if (ret)
246		goto out_uninit;
247
248	dev_set_drvdata(dev, vdev);
249	return 0;
250
251out_uninit:
252	vfio_put_device(&vdev->vdev);
253	return ret;
254}
255
256static int vfio_cdx_remove(struct cdx_device *cdx_dev)
257{
258	struct device *dev = &cdx_dev->dev;
259	struct vfio_cdx_device *vdev = dev_get_drvdata(dev);
260
261	vfio_unregister_group_dev(&vdev->vdev);
262	vfio_put_device(&vdev->vdev);
263
264	return 0;
265}
266
267static const struct cdx_device_id vfio_cdx_table[] = {
268	{ CDX_DEVICE_DRIVER_OVERRIDE(CDX_ANY_ID, CDX_ANY_ID,
269				     CDX_ID_F_VFIO_DRIVER_OVERRIDE) }, /* match all by default */
270	{}
271};
272
273MODULE_DEVICE_TABLE(cdx, vfio_cdx_table);
274
275static struct cdx_driver vfio_cdx_driver = {
276	.probe		= vfio_cdx_probe,
277	.remove		= vfio_cdx_remove,
278	.match_id_table	= vfio_cdx_table,
279	.driver	= {
280		.name	= "vfio-cdx",
281	},
282	.driver_managed_dma = true,
283};
284
285module_driver(vfio_cdx_driver, cdx_driver_register, cdx_driver_unregister);
286
287MODULE_LICENSE("GPL");
288MODULE_DESCRIPTION("VFIO for CDX devices - User Level meta-driver");
289MODULE_IMPORT_NS(CDX_BUS);
290