1 /*
2 * AMD Cryptographic Coprocessor (CCP) driver
3 *
4 * Copyright (C) 2014 Advanced Micro Devices, Inc.
5 *
6 * Author: Tom Lendacky <thomas.lendacky@amd.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/device.h>
16 #include <linux/platform_device.h>
17 #include <linux/ioport.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/kthread.h>
20 #include <linux/sched.h>
21 #include <linux/interrupt.h>
22 #include <linux/spinlock.h>
23 #include <linux/delay.h>
24 #include <linux/ccp.h>
25 #include <linux/of.h>
26 #include <linux/of_address.h>
27 #include <linux/acpi.h>
28
29 #include "ccp-dev.h"
30
31 struct ccp_platform {
32 int use_acpi;
33 int coherent;
34 };
35
ccp_get_irq(struct ccp_device * ccp)36 static int ccp_get_irq(struct ccp_device *ccp)
37 {
38 struct device *dev = ccp->dev;
39 struct platform_device *pdev = container_of(dev,
40 struct platform_device, dev);
41 int ret;
42
43 ret = platform_get_irq(pdev, 0);
44 if (ret < 0)
45 return ret;
46
47 ccp->irq = ret;
48 ret = request_irq(ccp->irq, ccp_irq_handler, 0, "ccp", dev);
49 if (ret) {
50 dev_notice(dev, "unable to allocate IRQ (%d)\n", ret);
51 return ret;
52 }
53
54 return 0;
55 }
56
ccp_get_irqs(struct ccp_device * ccp)57 static int ccp_get_irqs(struct ccp_device *ccp)
58 {
59 struct device *dev = ccp->dev;
60 int ret;
61
62 ret = ccp_get_irq(ccp);
63 if (!ret)
64 return 0;
65
66 /* Couldn't get an interrupt */
67 dev_notice(dev, "could not enable interrupts (%d)\n", ret);
68
69 return ret;
70 }
71
ccp_free_irqs(struct ccp_device * ccp)72 static void ccp_free_irqs(struct ccp_device *ccp)
73 {
74 struct device *dev = ccp->dev;
75
76 free_irq(ccp->irq, dev);
77 }
78
ccp_find_mmio_area(struct ccp_device * ccp)79 static struct resource *ccp_find_mmio_area(struct ccp_device *ccp)
80 {
81 struct device *dev = ccp->dev;
82 struct platform_device *pdev = container_of(dev,
83 struct platform_device, dev);
84 struct resource *ior;
85
86 ior = platform_get_resource(pdev, IORESOURCE_MEM, 0);
87 if (ior && (resource_size(ior) >= 0x800))
88 return ior;
89
90 return NULL;
91 }
92
93 #ifdef CONFIG_ACPI
ccp_acpi_support(struct ccp_device * ccp)94 static int ccp_acpi_support(struct ccp_device *ccp)
95 {
96 struct ccp_platform *ccp_platform = ccp->dev_specific;
97 struct acpi_device *adev = ACPI_COMPANION(ccp->dev);
98 acpi_handle handle;
99 acpi_status status;
100 unsigned long long data;
101 int cca;
102
103 /* Retrieve the device cache coherency value */
104 handle = adev->handle;
105 do {
106 status = acpi_evaluate_integer(handle, "_CCA", NULL, &data);
107 if (!ACPI_FAILURE(status)) {
108 cca = data;
109 break;
110 }
111 } while (!ACPI_FAILURE(status));
112
113 if (ACPI_FAILURE(status)) {
114 dev_err(ccp->dev, "error obtaining acpi coherency value\n");
115 return -EINVAL;
116 }
117
118 ccp_platform->coherent = !!cca;
119
120 return 0;
121 }
122 #else /* CONFIG_ACPI */
ccp_acpi_support(struct ccp_device * ccp)123 static int ccp_acpi_support(struct ccp_device *ccp)
124 {
125 return -EINVAL;
126 }
127 #endif
128
129 #ifdef CONFIG_OF
ccp_of_support(struct ccp_device * ccp)130 static int ccp_of_support(struct ccp_device *ccp)
131 {
132 struct ccp_platform *ccp_platform = ccp->dev_specific;
133
134 ccp_platform->coherent = of_dma_is_coherent(ccp->dev->of_node);
135
136 return 0;
137 }
138 #else
ccp_of_support(struct ccp_device * ccp)139 static int ccp_of_support(struct ccp_device *ccp)
140 {
141 return -EINVAL;
142 }
143 #endif
144
ccp_platform_probe(struct platform_device * pdev)145 static int ccp_platform_probe(struct platform_device *pdev)
146 {
147 struct ccp_device *ccp;
148 struct ccp_platform *ccp_platform;
149 struct device *dev = &pdev->dev;
150 struct acpi_device *adev = ACPI_COMPANION(dev);
151 struct resource *ior;
152 int ret;
153
154 ret = -ENOMEM;
155 ccp = ccp_alloc_struct(dev);
156 if (!ccp)
157 goto e_err;
158
159 ccp_platform = devm_kzalloc(dev, sizeof(*ccp_platform), GFP_KERNEL);
160 if (!ccp_platform)
161 goto e_err;
162
163 ccp->dev_specific = ccp_platform;
164 ccp->get_irq = ccp_get_irqs;
165 ccp->free_irq = ccp_free_irqs;
166
167 ccp_platform->use_acpi = (!adev || acpi_disabled) ? 0 : 1;
168
169 ior = ccp_find_mmio_area(ccp);
170 ccp->io_map = devm_ioremap_resource(dev, ior);
171 if (IS_ERR(ccp->io_map)) {
172 ret = PTR_ERR(ccp->io_map);
173 goto e_err;
174 }
175 ccp->io_regs = ccp->io_map;
176
177 if (!dev->dma_mask)
178 dev->dma_mask = &dev->coherent_dma_mask;
179 ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
180 if (ret) {
181 dev_err(dev, "dma_set_mask_and_coherent failed (%d)\n", ret);
182 goto e_err;
183 }
184
185 if (ccp_platform->use_acpi)
186 ret = ccp_acpi_support(ccp);
187 else
188 ret = ccp_of_support(ccp);
189 if (ret)
190 goto e_err;
191
192 if (ccp_platform->coherent)
193 ccp->axcache = CACHE_WB_NO_ALLOC;
194 else
195 ccp->axcache = CACHE_NONE;
196
197 dev_set_drvdata(dev, ccp);
198
199 ret = ccp_init(ccp);
200 if (ret)
201 goto e_err;
202
203 dev_notice(dev, "enabled\n");
204
205 return 0;
206
207 e_err:
208 dev_notice(dev, "initialization failed\n");
209 return ret;
210 }
211
ccp_platform_remove(struct platform_device * pdev)212 static int ccp_platform_remove(struct platform_device *pdev)
213 {
214 struct device *dev = &pdev->dev;
215 struct ccp_device *ccp = dev_get_drvdata(dev);
216
217 ccp_destroy(ccp);
218
219 dev_notice(dev, "disabled\n");
220
221 return 0;
222 }
223
224 #ifdef CONFIG_PM
ccp_platform_suspend(struct platform_device * pdev,pm_message_t state)225 static int ccp_platform_suspend(struct platform_device *pdev,
226 pm_message_t state)
227 {
228 struct device *dev = &pdev->dev;
229 struct ccp_device *ccp = dev_get_drvdata(dev);
230 unsigned long flags;
231 unsigned int i;
232
233 spin_lock_irqsave(&ccp->cmd_lock, flags);
234
235 ccp->suspending = 1;
236
237 /* Wake all the queue kthreads to prepare for suspend */
238 for (i = 0; i < ccp->cmd_q_count; i++)
239 wake_up_process(ccp->cmd_q[i].kthread);
240
241 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
242
243 /* Wait for all queue kthreads to say they're done */
244 while (!ccp_queues_suspended(ccp))
245 wait_event_interruptible(ccp->suspend_queue,
246 ccp_queues_suspended(ccp));
247
248 return 0;
249 }
250
ccp_platform_resume(struct platform_device * pdev)251 static int ccp_platform_resume(struct platform_device *pdev)
252 {
253 struct device *dev = &pdev->dev;
254 struct ccp_device *ccp = dev_get_drvdata(dev);
255 unsigned long flags;
256 unsigned int i;
257
258 spin_lock_irqsave(&ccp->cmd_lock, flags);
259
260 ccp->suspending = 0;
261
262 /* Wake up all the kthreads */
263 for (i = 0; i < ccp->cmd_q_count; i++) {
264 ccp->cmd_q[i].suspended = 0;
265 wake_up_process(ccp->cmd_q[i].kthread);
266 }
267
268 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
269
270 return 0;
271 }
272 #endif
273
274 #ifdef CONFIG_ACPI
275 static const struct acpi_device_id ccp_acpi_match[] = {
276 { "AMDI0C00", 0 },
277 { },
278 };
279 #endif
280
281 #ifdef CONFIG_OF
282 static const struct of_device_id ccp_of_match[] = {
283 { .compatible = "amd,ccp-seattle-v1a" },
284 { },
285 };
286 #endif
287
288 static struct platform_driver ccp_platform_driver = {
289 .driver = {
290 .name = "AMD Cryptographic Coprocessor",
291 #ifdef CONFIG_ACPI
292 .acpi_match_table = ccp_acpi_match,
293 #endif
294 #ifdef CONFIG_OF
295 .of_match_table = ccp_of_match,
296 #endif
297 },
298 .probe = ccp_platform_probe,
299 .remove = ccp_platform_remove,
300 #ifdef CONFIG_PM
301 .suspend = ccp_platform_suspend,
302 .resume = ccp_platform_resume,
303 #endif
304 };
305
ccp_platform_init(void)306 int ccp_platform_init(void)
307 {
308 return platform_driver_register(&ccp_platform_driver);
309 }
310
ccp_platform_exit(void)311 void ccp_platform_exit(void)
312 {
313 platform_driver_unregister(&ccp_platform_driver);
314 }
315