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
31struct ccp_platform {
32	int use_acpi;
33	int coherent;
34};
35
36static 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
57static 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
72static void ccp_free_irqs(struct ccp_device *ccp)
73{
74	struct device *dev = ccp->dev;
75
76	free_irq(ccp->irq, dev);
77}
78
79static 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
94static 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 */
123static int ccp_acpi_support(struct ccp_device *ccp)
124{
125	return -EINVAL;
126}
127#endif
128
129#ifdef CONFIG_OF
130static 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
139static int ccp_of_support(struct ccp_device *ccp)
140{
141	return -EINVAL;
142}
143#endif
144
145static 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
207e_err:
208	dev_notice(dev, "initialization failed\n");
209	return ret;
210}
211
212static 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
225static 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
251static 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
275static const struct acpi_device_id ccp_acpi_match[] = {
276	{ "AMDI0C00", 0 },
277	{ },
278};
279#endif
280
281#ifdef CONFIG_OF
282static const struct of_device_id ccp_of_match[] = {
283	{ .compatible = "amd,ccp-seattle-v1a" },
284	{ },
285};
286#endif
287
288static 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
306int ccp_platform_init(void)
307{
308	return platform_driver_register(&ccp_platform_driver);
309}
310
311void ccp_platform_exit(void)
312{
313	platform_driver_unregister(&ccp_platform_driver);
314}
315