1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AMD Passthru DMA device driver
4 * -- Based on the CCP driver
5 *
6 * Copyright (C) 2016,2021 Advanced Micro Devices, Inc.
7 *
8 * Author: Sanjay R Mehta <sanju.mehta@amd.com>
9 * Author: Tom Lendacky <thomas.lendacky@amd.com>
10 * Author: Gary R Hook <gary.hook@amd.com>
11 */
12
13#include <linux/device.h>
14#include <linux/dma-mapping.h>
15#include <linux/delay.h>
16#include <linux/interrupt.h>
17#include <linux/kernel.h>
18#include <linux/kthread.h>
19#include <linux/module.h>
20#include <linux/pci_ids.h>
21#include <linux/pci.h>
22#include <linux/spinlock.h>
23
24#include "ptdma.h"
25
26struct pt_msix {
27 int msix_count;
28 struct msix_entry msix_entry;
29};
30
31/*
32 * pt_alloc_struct - allocate and initialize the pt_device struct
33 *
34 * @dev: device struct of the PTDMA
35 */
36static struct pt_device *pt_alloc_struct(struct device *dev)
37{
38 struct pt_device *pt;
39
40 pt = devm_kzalloc(dev, size: sizeof(*pt), GFP_KERNEL);
41
42 if (!pt)
43 return NULL;
44 pt->dev = dev;
45
46 INIT_LIST_HEAD(list: &pt->cmd);
47
48 return pt;
49}
50
51static int pt_get_msix_irqs(struct pt_device *pt)
52{
53 struct pt_msix *pt_msix = pt->pt_msix;
54 struct device *dev = pt->dev;
55 struct pci_dev *pdev = to_pci_dev(dev);
56 int ret;
57
58 pt_msix->msix_entry.entry = 0;
59
60 ret = pci_enable_msix_range(dev: pdev, entries: &pt_msix->msix_entry, minvec: 1, maxvec: 1);
61 if (ret < 0)
62 return ret;
63
64 pt_msix->msix_count = ret;
65
66 pt->pt_irq = pt_msix->msix_entry.vector;
67
68 return 0;
69}
70
71static int pt_get_msi_irq(struct pt_device *pt)
72{
73 struct device *dev = pt->dev;
74 struct pci_dev *pdev = to_pci_dev(dev);
75 int ret;
76
77 ret = pci_enable_msi(dev: pdev);
78 if (ret)
79 return ret;
80
81 pt->pt_irq = pdev->irq;
82
83 return 0;
84}
85
86static int pt_get_irqs(struct pt_device *pt)
87{
88 struct device *dev = pt->dev;
89 int ret;
90
91 ret = pt_get_msix_irqs(pt);
92 if (!ret)
93 return 0;
94
95 /* Couldn't get MSI-X vectors, try MSI */
96 dev_err(dev, "could not enable MSI-X (%d), trying MSI\n", ret);
97 ret = pt_get_msi_irq(pt);
98 if (!ret)
99 return 0;
100
101 /* Couldn't get MSI interrupt */
102 dev_err(dev, "could not enable MSI (%d)\n", ret);
103
104 return ret;
105}
106
107static void pt_free_irqs(struct pt_device *pt)
108{
109 struct pt_msix *pt_msix = pt->pt_msix;
110 struct device *dev = pt->dev;
111 struct pci_dev *pdev = to_pci_dev(dev);
112
113 if (pt_msix->msix_count)
114 pci_disable_msix(dev: pdev);
115 else if (pt->pt_irq)
116 pci_disable_msi(dev: pdev);
117
118 pt->pt_irq = 0;
119}
120
121static int pt_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
122{
123 struct pt_device *pt;
124 struct pt_msix *pt_msix;
125 struct device *dev = &pdev->dev;
126 void __iomem * const *iomap_table;
127 int bar_mask;
128 int ret = -ENOMEM;
129
130 pt = pt_alloc_struct(dev);
131 if (!pt)
132 goto e_err;
133
134 pt_msix = devm_kzalloc(dev, size: sizeof(*pt_msix), GFP_KERNEL);
135 if (!pt_msix)
136 goto e_err;
137
138 pt->pt_msix = pt_msix;
139 pt->dev_vdata = (struct pt_dev_vdata *)id->driver_data;
140 if (!pt->dev_vdata) {
141 ret = -ENODEV;
142 dev_err(dev, "missing driver data\n");
143 goto e_err;
144 }
145
146 ret = pcim_enable_device(pdev);
147 if (ret) {
148 dev_err(dev, "pcim_enable_device failed (%d)\n", ret);
149 goto e_err;
150 }
151
152 bar_mask = pci_select_bars(dev: pdev, IORESOURCE_MEM);
153 ret = pcim_iomap_regions(pdev, mask: bar_mask, name: "ptdma");
154 if (ret) {
155 dev_err(dev, "pcim_iomap_regions failed (%d)\n", ret);
156 goto e_err;
157 }
158
159 iomap_table = pcim_iomap_table(pdev);
160 if (!iomap_table) {
161 dev_err(dev, "pcim_iomap_table failed\n");
162 ret = -ENOMEM;
163 goto e_err;
164 }
165
166 pt->io_regs = iomap_table[pt->dev_vdata->bar];
167 if (!pt->io_regs) {
168 dev_err(dev, "ioremap failed\n");
169 ret = -ENOMEM;
170 goto e_err;
171 }
172
173 ret = pt_get_irqs(pt);
174 if (ret)
175 goto e_err;
176
177 pci_set_master(dev: pdev);
178
179 ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
180 if (ret) {
181 ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
182 if (ret) {
183 dev_err(dev, "dma_set_mask_and_coherent failed (%d)\n",
184 ret);
185 goto e_err;
186 }
187 }
188
189 dev_set_drvdata(dev, data: pt);
190
191 if (pt->dev_vdata)
192 ret = pt_core_init(pt);
193
194 if (ret)
195 goto e_err;
196
197 return 0;
198
199e_err:
200 dev_err(dev, "initialization failed ret = %d\n", ret);
201
202 return ret;
203}
204
205static void pt_pci_remove(struct pci_dev *pdev)
206{
207 struct device *dev = &pdev->dev;
208 struct pt_device *pt = dev_get_drvdata(dev);
209
210 if (!pt)
211 return;
212
213 if (pt->dev_vdata)
214 pt_core_destroy(pt);
215
216 pt_free_irqs(pt);
217}
218
219static const struct pt_dev_vdata dev_vdata[] = {
220 {
221 .bar = 2,
222 },
223};
224
225static const struct pci_device_id pt_pci_table[] = {
226 { PCI_VDEVICE(AMD, 0x1498), (kernel_ulong_t)&dev_vdata[0] },
227 /* Last entry must be zero */
228 { 0, }
229};
230MODULE_DEVICE_TABLE(pci, pt_pci_table);
231
232static struct pci_driver pt_pci_driver = {
233 .name = "ptdma",
234 .id_table = pt_pci_table,
235 .probe = pt_pci_probe,
236 .remove = pt_pci_remove,
237};
238
239module_pci_driver(pt_pci_driver);
240
241MODULE_AUTHOR("Sanjay R Mehta <sanju.mehta@amd.com>");
242MODULE_LICENSE("GPL");
243MODULE_DESCRIPTION("AMD PassThru DMA driver");
244

source code of linux/drivers/dma/ptdma/ptdma-pci.c