[mirror_ubuntu-jammy-kernel.git] / arch / powerpc / platforms / powernv / opal-prd.c

/*
 * OPAL Runtime Diagnostics interface driver
 * Supported on POWERNV platform
 *
 * Copyright IBM Corporation 2015
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt) "opal-prd: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/poll.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/opal-prd.h>
#include <asm/opal.h>
#include <asm/io.h>
#include <asm/uaccess.h>


struct opal_prd_msg_queue_item {
	struct opal_prd_msg_header	msg;
	struct list_head		list;
};

static struct device_node *prd_node;
static LIST_HEAD(opal_prd_msg_queue);
static DEFINE_SPINLOCK(opal_prd_msg_queue_lock);
static DECLARE_WAIT_QUEUE_HEAD(opal_prd_msg_wait);
static atomic_t prd_usage;

static bool opal_prd_range_is_valid(uint64_t addr, uint64_t size)
{
	struct device_node *parent, *node;
	bool found;

	if (addr + size < addr)
		return false;

	parent = of_find_node_by_path("/reserved-memory");
	if (!parent)
		return false;

	found = false;

	for_each_child_of_node(parent, node) {
		uint64_t range_addr, range_size, range_end;
		const __be32 *addrp;
		const char *label;

		addrp = of_get_address(node, 0, &range_size, NULL);

		range_addr = of_read_number(addrp, 2);
		range_end = range_addr + range_size;

		label = of_get_property(node, "ibm,prd-label", NULL);

		/* PRD ranges need a label */
		if (!label)
			continue;

		if (range_end <= range_addr)
			continue;

		if (addr >= range_addr && addr + size <= range_end) {
			found = true;
			of_node_put(node);
			break;
		}
	}

	of_node_put(parent);
	return found;
}

static int opal_prd_open(struct inode *inode, struct file *file)
{
	/*
	 * Prevent multiple (separate) processes from concurrent interactions
	 * with the FW PRD channel
	 */
	if (atomic_xchg(&prd_usage, 1) == 1)
		return -EBUSY;

	return 0;
}

/*
 * opal_prd_mmap - maps firmware-provided ranges into userspace
 * @file: file structure for the device
 * @vma: VMA to map the registers into
 */

static int opal_prd_mmap(struct file *file, struct vm_area_struct *vma)
{
	size_t addr, size;
	int rc;

	pr_devel("opal_prd_mmap(0x%016lx, 0x%016lx, 0x%lx, 0x%lx)\n",
			vma->vm_start, vma->vm_end, vma->vm_pgoff,
			vma->vm_flags);

	addr = vma->vm_pgoff << PAGE_SHIFT;
	size = vma->vm_end - vma->vm_start;

	/* ensure we're mapping within one of the allowable ranges */
	if (!opal_prd_range_is_valid(addr, size))
		return -EINVAL;

	vma->vm_page_prot = __pgprot(pgprot_val(phys_mem_access_prot(file,
						vma->vm_pgoff,
						 size, vma->vm_page_prot))
					| _PAGE_SPECIAL);

	rc = remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, size,
			vma->vm_page_prot);

	return rc;
}

static bool opal_msg_queue_empty(void)
{
	unsigned long flags;
	bool ret;

	spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
	ret = list_empty(&opal_prd_msg_queue);
	spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);

	return ret;
}

static unsigned int opal_prd_poll(struct file *file,
		struct poll_table_struct *wait)
{
	poll_wait(file, &opal_prd_msg_wait, wait);

	if (!opal_msg_queue_empty())
		return POLLIN | POLLRDNORM;

	return 0;
}

static ssize_t opal_prd_read(struct file *file, char __user *buf,
		size_t count, loff_t *ppos)
{
	struct opal_prd_msg_queue_item *item;
	unsigned long flags;
	ssize_t size, err;
	int rc;

	/* we need at least a header's worth of data */
	if (count < sizeof(item->msg))
		return -EINVAL;

	if (*ppos)
		return -ESPIPE;

	item = NULL;

	for (;;) {

		spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
		if (!list_empty(&opal_prd_msg_queue)) {
			item = list_first_entry(&opal_prd_msg_queue,
					struct opal_prd_msg_queue_item, list);
			list_del(&item->list);
		}
		spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);

		if (item)
			break;

		if (file->f_flags & O_NONBLOCK)
			return -EAGAIN;

		rc = wait_event_interruptible(opal_prd_msg_wait,
				!opal_msg_queue_empty());
		if (rc)
			return -EINTR;
	}

	size = be16_to_cpu(item->msg.size);
	if (size > count) {
		err = -EINVAL;
		goto err_requeue;
	}

	rc = copy_to_user(buf, &item->msg, size);
	if (rc) {
		err = -EFAULT;
		goto err_requeue;
	}

	kfree(item);

	return size;

err_requeue:
	/* eep! re-queue at the head of the list */
	spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
	list_add(&item->list, &opal_prd_msg_queue);
	spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
	return err;
}

static ssize_t opal_prd_write(struct file *file, const char __user *buf,
		size_t count, loff_t *ppos)
{
	struct opal_prd_msg_header hdr;
	ssize_t size;
	void *msg;
	int rc;

	size = sizeof(hdr);

	if (count < size)
		return -EINVAL;

	/* grab the header */
	rc = copy_from_user(&hdr, buf, sizeof(hdr));
	if (rc)
		return -EFAULT;

	size = be16_to_cpu(hdr.size);

	msg = kmalloc(size, GFP_KERNEL);
	if (!msg)
		return -ENOMEM;

	rc = copy_from_user(msg, buf, size);
	if (rc) {
		size = -EFAULT;
		goto out_free;
	}

	rc = opal_prd_msg(msg);
	if (rc) {
		pr_warn("write: opal_prd_msg returned %d\n", rc);
		size = -EIO;
	}

out_free:
	kfree(msg);

	return size;
}

static int opal_prd_release(struct inode *inode, struct file *file)
{
	struct opal_prd_msg_header msg;

	msg.size = cpu_to_be16(sizeof(msg));
	msg.type = OPAL_PRD_MSG_TYPE_FINI;

	opal_prd_msg((struct opal_prd_msg *)&msg);

	atomic_xchg(&prd_usage, 0);

	return 0;
}

static long opal_prd_ioctl(struct file *file, unsigned int cmd,
		unsigned long param)
{
	struct opal_prd_info info;
	struct opal_prd_scom scom;
	int rc = 0;

	switch (cmd) {
	case OPAL_PRD_GET_INFO:
		memset(&info, 0, sizeof(info));
		info.version = OPAL_PRD_KERNEL_VERSION;
		rc = copy_to_user((void __user *)param, &info, sizeof(info));
		if (rc)
			return -EFAULT;
		break;

	case OPAL_PRD_SCOM_READ:
		rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
		if (rc)
			return -EFAULT;

		scom.rc = opal_xscom_read(scom.chip, scom.addr,
				(__be64 *)&scom.data);
		scom.data = be64_to_cpu(scom.data);
		pr_devel("ioctl SCOM_READ: chip %llx addr %016llx data %016llx rc %lld\n",
				scom.chip, scom.addr, scom.data, scom.rc);

		rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
		if (rc)
			return -EFAULT;
		break;

	case OPAL_PRD_SCOM_WRITE:
		rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
		if (rc)
			return -EFAULT;

		scom.rc = opal_xscom_write(scom.chip, scom.addr, scom.data);
		pr_devel("ioctl SCOM_WRITE: chip %llx addr %016llx data %016llx rc %lld\n",
				scom.chip, scom.addr, scom.data, scom.rc);

		rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
		if (rc)
			return -EFAULT;
		break;

	default:
		rc = -EINVAL;
	}

	return rc;
}

static const struct file_operations opal_prd_fops = {
	.open		= opal_prd_open,
	.mmap		= opal_prd_mmap,
	.poll		= opal_prd_poll,
	.read		= opal_prd_read,
	.write		= opal_prd_write,
	.unlocked_ioctl	= opal_prd_ioctl,
	.release	= opal_prd_release,
	.owner		= THIS_MODULE,
};

static struct miscdevice opal_prd_dev = {
	.minor		= MISC_DYNAMIC_MINOR,
	.name		= "opal-prd",
	.fops		= &opal_prd_fops,
};

/* opal interface */
static int opal_prd_msg_notifier(struct notifier_block *nb,
		unsigned long msg_type, void *_msg)
{
	struct opal_prd_msg_queue_item *item;
	struct opal_prd_msg_header *hdr;
	struct opal_msg *msg = _msg;
	unsigned long flags;
	int size;

	if (msg_type != OPAL_MSG_PRD)
		return 0;

	/* Calculate total size of the item we need to store. The 'size' field
	 * in the header includes the header itself. */
	hdr = (void *)msg->params;
	size = (sizeof(*item) - sizeof(item->msg)) + be16_to_cpu(hdr->size);

	item = kzalloc(size, GFP_ATOMIC);
	if (!item)
		return -ENOMEM;

	memcpy(&item->msg, msg->params, size);

	spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
	list_add_tail(&item->list, &opal_prd_msg_queue);
	spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);

	wake_up_interruptible(&opal_prd_msg_wait);

	return 0;
}

static struct notifier_block opal_prd_event_nb = {
	.notifier_call	= opal_prd_msg_notifier,
	.next		= NULL,
	.priority	= 0,
};

static int opal_prd_probe(struct platform_device *pdev)
{
	int rc;

	if (!pdev || !pdev->dev.of_node)
		return -ENODEV;

	/* We should only have one prd driver instance per machine; ensure
	 * that we only get a valid probe on a single OF node.
	 */
	if (prd_node)
		return -EBUSY;

	prd_node = pdev->dev.of_node;

	rc = opal_message_notifier_register(OPAL_MSG_PRD, &opal_prd_event_nb);
	if (rc) {
		pr_err("Couldn't register event notifier\n");
		return rc;
	}

	rc = misc_register(&opal_prd_dev);
	if (rc) {
		pr_err("failed to register miscdev\n");
		opal_message_notifier_unregister(OPAL_MSG_PRD,
				&opal_prd_event_nb);
		return rc;
	}

	return 0;
}

static int opal_prd_remove(struct platform_device *pdev)
{
	misc_deregister(&opal_prd_dev);
	opal_message_notifier_unregister(OPAL_MSG_PRD, &opal_prd_event_nb);
	return 0;
}

static const struct of_device_id opal_prd_match[] = {
	{ .compatible = "ibm,opal-prd" },
	{ },
};

static struct platform_driver opal_prd_driver = {
	.driver = {
		.name		= "opal-prd",
		.owner		= THIS_MODULE,
		.of_match_table	= opal_prd_match,
	},
	.probe	= opal_prd_probe,
	.remove	= opal_prd_remove,
};

module_platform_driver(opal_prd_driver);

MODULE_DEVICE_TABLE(of, opal_prd_match);
MODULE_DESCRIPTION("PowerNV OPAL runtime diagnostic driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
0d7cd855 JK	1	/*
	2	* OPAL Runtime Diagnostics interface driver
	3	* Supported on POWERNV platform
	4	*
	5	* Copyright IBM Corporation 2015
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*/
	16
	17	#define pr_fmt(fmt) "opal-prd: " fmt
	18
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/miscdevice.h>
	23	#include <linux/fs.h>
	24	#include <linux/of.h>
	25	#include <linux/of_address.h>
	26	#include <linux/poll.h>
	27	#include <linux/mm.h>
	28	#include <linux/slab.h>
	29	#include <asm/opal-prd.h>
	30	#include <asm/opal.h>
	31	#include <asm/io.h>
	32	#include <asm/uaccess.h>
	33
	34
	35	struct opal_prd_msg_queue_item {
	36	struct opal_prd_msg_header msg;
	37	struct list_head list;
	38	};
	39
	40	static struct device_node *prd_node;
	41	static LIST_HEAD(opal_prd_msg_queue);
	42	static DEFINE_SPINLOCK(opal_prd_msg_queue_lock);
	43	static DECLARE_WAIT_QUEUE_HEAD(opal_prd_msg_wait);
	44	static atomic_t prd_usage;
	45
	46	static bool opal_prd_range_is_valid(uint64_t addr, uint64_t size)
	47	{
	48	struct device_node parent, node;
	49	bool found;
	50
	51	if (addr + size < addr)
	52	return false;
	53
	54	parent = of_find_node_by_path("/reserved-memory");
	55	if (!parent)
	56	return false;
	57
	58	found = false;
	59
	60	for_each_child_of_node(parent, node) {
	61	uint64_t range_addr, range_size, range_end;
	62	const __be32 *addrp;
	63	const char *label;
	64
65	addrp = of_get_address(node, 0, &range_size, NULL);
66
67	range_addr = of_read_number(addrp, 2);
68	range_end = range_addr + range_size;
69
70	label = of_get_property(node, "ibm,prd-label", NULL);
71
72	/* PRD ranges need a label */
73	if (!label)
74	continue;
75
76	if (range_end <= range_addr)
77	continue;
78
79	if (addr >= range_addr && addr + size <= range_end) {
80	found = true;
81	of_node_put(node);
82	break;
83	}
84	}
85
86	of_node_put(parent);
87	return found;
88	}
89
90	static int opal_prd_open(struct inode inode, struct file file)
91	{
92	/*
93	* Prevent multiple (separate) processes from concurrent interactions
94	* with the FW PRD channel
95	*/
96	if (atomic_xchg(&prd_usage, 1) == 1)
97	return -EBUSY;
98
99	return 0;
100	}
101
102	/*
103	* opal_prd_mmap - maps firmware-provided ranges into userspace
104	* @file: file structure for the device
105	* @vma: VMA to map the registers into
106	*/
107
108	static int opal_prd_mmap(struct file file, struct vm_area_struct vma)
109	{
110	size_t addr, size;
111	int rc;
112
113	pr_devel("opal_prd_mmap(0x%016lx, 0x%016lx, 0x%lx, 0x%lx)\n",
114	vma->vm_start, vma->vm_end, vma->vm_pgoff,
115	vma->vm_flags);
116
117	addr = vma->vm_pgoff << PAGE_SHIFT;
118	size = vma->vm_end - vma->vm_start;
119
120	/* ensure we're mapping within one of the allowable ranges */
121	if (!opal_prd_range_is_valid(addr, size))
122	return -EINVAL;
123
124	vma->vm_page_prot = __pgprot(pgprot_val(phys_mem_access_prot(file,
125	vma->vm_pgoff,
126	size, vma->vm_page_prot))
127	\| _PAGE_SPECIAL);
128
129	rc = remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, size,
130	vma->vm_page_prot);
131
132	return rc;
133	}
134
135	static bool opal_msg_queue_empty(void)
136	{
137	unsigned long flags;
138	bool ret;
139
140	spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
141	ret = list_empty(&opal_prd_msg_queue);
142	spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
143
144	return ret;
145	}
146
147	static unsigned int opal_prd_poll(struct file *file,
148	struct poll_table_struct *wait)
149	{
150	poll_wait(file, &opal_prd_msg_wait, wait);
151
152	if (!opal_msg_queue_empty())
153	return POLLIN \| POLLRDNORM;
154
155	return 0;
156	}
157
158	static ssize_t opal_prd_read(struct file file, char __user buf,
159	size_t count, loff_t *ppos)
160	{
161	struct opal_prd_msg_queue_item *item;
162	unsigned long flags;
163	ssize_t size, err;
164	int rc;
165
166	/* we need at least a header's worth of data */
167	if (count < sizeof(item->msg))
168	return -EINVAL;
169
170	if (*ppos)
171	return -ESPIPE;
172
173	item = NULL;
174
175	for (;;) {
176
177	spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
178	if (!list_empty(&opal_prd_msg_queue)) {
179	item = list_first_entry(&opal_prd_msg_queue,
180	struct opal_prd_msg_queue_item, list);
181	list_del(&item->list);
182	}
183	spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
184
185	if (item)
186	break;
187
188	if (file->f_flags & O_NONBLOCK)
189	return -EAGAIN;
190
191	rc = wait_event_interruptible(opal_prd_msg_wait,
192	!opal_msg_queue_empty());
193	if (rc)
194	return -EINTR;
195	}
196
197	size = be16_to_cpu(item->msg.size);
198	if (size > count) {
199	err = -EINVAL;
200	goto err_requeue;
201	}
202
203	rc = copy_to_user(buf, &item->msg, size);
204	if (rc) {
205	err = -EFAULT;
206	goto err_requeue;
207	}
208
209	kfree(item);
210
211	return size;
212
213	err_requeue:
214	/* eep! re-queue at the head of the list */
215	spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
216	list_add(&item->list, &opal_prd_msg_queue);
217	spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
218	return err;
219	}
220
221	static ssize_t opal_prd_write(struct file file, const char __user buf,
222	size_t count, loff_t *ppos)
223	{
224	struct opal_prd_msg_header hdr;
225	ssize_t size;
226	void *msg;
227	int rc;
228
229	size = sizeof(hdr);
230
231	if (count < size)
232	return -EINVAL;
233
234	/* grab the header */
235	rc = copy_from_user(&hdr, buf, sizeof(hdr));
236	if (rc)
237	return -EFAULT;
238
239	size = be16_to_cpu(hdr.size);
240
241	msg = kmalloc(size, GFP_KERNEL);
242	if (!msg)
243	return -ENOMEM;
244
245	rc = copy_from_user(msg, buf, size);
246	if (rc) {
247	size = -EFAULT;
248	goto out_free;
249	}
250
251	rc = opal_prd_msg(msg);
252	if (rc) {
253	pr_warn("write: opal_prd_msg returned %d\n", rc);
254	size = -EIO;
255	}
256
257	out_free:
258	kfree(msg);
259
260	return size;
261	}
262
263	static int opal_prd_release(struct inode inode, struct file file)
264	{
265	struct opal_prd_msg_header msg;
266
267	msg.size = cpu_to_be16(sizeof(msg));
268	msg.type = OPAL_PRD_MSG_TYPE_FINI;
269
270	opal_prd_msg((struct opal_prd_msg *)&msg);
271
272	atomic_xchg(&prd_usage, 0);
273
274	return 0;
275	}
276
277	static long opal_prd_ioctl(struct file *file, unsigned int cmd,
278	unsigned long param)
279	{
280	struct opal_prd_info info;
281	struct opal_prd_scom scom;
282	int rc = 0;
283
284	switch (cmd) {
285	case OPAL_PRD_GET_INFO:
286	memset(&info, 0, sizeof(info));
287	info.version = OPAL_PRD_KERNEL_VERSION;
288	rc = copy_to_user((void __user *)param, &info, sizeof(info));
289	if (rc)
290	return -EFAULT;
291	break;
292
293	case OPAL_PRD_SCOM_READ:
294	rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
295	if (rc)
296	return -EFAULT;
297
298	scom.rc = opal_xscom_read(scom.chip, scom.addr,
299	(__be64 *)&scom.data);
300	scom.data = be64_to_cpu(scom.data);
301	pr_devel("ioctl SCOM_READ: chip %llx addr %016llx data %016llx rc %lld\n",
302	scom.chip, scom.addr, scom.data, scom.rc);
303
304	rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
305	if (rc)
306	return -EFAULT;
307	break;
308
309	case OPAL_PRD_SCOM_WRITE:
310	rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
311	if (rc)
312	return -EFAULT;
313
314	scom.rc = opal_xscom_write(scom.chip, scom.addr, scom.data);
315	pr_devel("ioctl SCOM_WRITE: chip %llx addr %016llx data %016llx rc %lld\n",
316	scom.chip, scom.addr, scom.data, scom.rc);
317
318	rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
319	if (rc)
320	return -EFAULT;
321	break;
322
323	default:
324	rc = -EINVAL;
325	}
326
327	return rc;
328	}
329
330	static const struct file_operations opal_prd_fops = {
331	.open = opal_prd_open,
332	.mmap = opal_prd_mmap,
333	.poll = opal_prd_poll,
334	.read = opal_prd_read,
335	.write = opal_prd_write,
336	.unlocked_ioctl = opal_prd_ioctl,
337	.release = opal_prd_release,
338	.owner = THIS_MODULE,
339	};
340
341	static struct miscdevice opal_prd_dev = {
342	.minor = MISC_DYNAMIC_MINOR,
343	.name = "opal-prd",
344	.fops = &opal_prd_fops,
345	};
346
347	/* opal interface */
348	static int opal_prd_msg_notifier(struct notifier_block *nb,
349	unsigned long msg_type, void *_msg)
350	{
351	struct opal_prd_msg_queue_item *item;
352	struct opal_prd_msg_header *hdr;
353	struct opal_msg *msg = _msg;
354	unsigned long flags;
355	int size;
356
357	if (msg_type != OPAL_MSG_PRD)
358	return 0;
359
360	/* Calculate total size of the item we need to store. The 'size' field
361	* in the header includes the header itself. */
362	hdr = (void *)msg->params;
363	size = (sizeof(*item) - sizeof(item->msg)) + be16_to_cpu(hdr->size);
364
365	item = kzalloc(size, GFP_ATOMIC);
366	if (!item)
367	return -ENOMEM;
368
369	memcpy(&item->msg, msg->params, size);
370
371	spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
372	list_add_tail(&item->list, &opal_prd_msg_queue);
373	spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
374
375	wake_up_interruptible(&opal_prd_msg_wait);
376
377	return 0;
378	}
379
380	static struct notifier_block opal_prd_event_nb = {
381	.notifier_call = opal_prd_msg_notifier,
382	.next = NULL,
383	.priority = 0,
384	};
385
386	static int opal_prd_probe(struct platform_device *pdev)
387	{
388	int rc;
389
390	if (!pdev \|\| !pdev->dev.of_node)
391	return -ENODEV;
392
393	/* We should only have one prd driver instance per machine; ensure
394	* that we only get a valid probe on a single OF node.
395	*/
396	if (prd_node)
397	return -EBUSY;
398
399	prd_node = pdev->dev.of_node;
400
401	rc = opal_message_notifier_register(OPAL_MSG_PRD, &opal_prd_event_nb);
402	if (rc) {
403	pr_err("Couldn't register event notifier\n");
404	return rc;
405	}
406
407	rc = misc_register(&opal_prd_dev);
408	if (rc) {
409	pr_err("failed to register miscdev\n");
410	opal_message_notifier_unregister(OPAL_MSG_PRD,
411	&opal_prd_event_nb);
412	return rc;
413	}
414
415	return 0;
416	}
417
418	static int opal_prd_remove(struct platform_device *pdev)
419	{
420	misc_deregister(&opal_prd_dev);
421	opal_message_notifier_unregister(OPAL_MSG_PRD, &opal_prd_event_nb);
422	return 0;
423	}
424
425	static const struct of_device_id opal_prd_match[] = {
426	{ .compatible = "ibm,opal-prd" },
427	{ },
428	};
429
430	static struct platform_driver opal_prd_driver = {
431	.driver = {
432	.name = "opal-prd",
433	.owner = THIS_MODULE,
434	.of_match_table = opal_prd_match,
435	},
436	.probe = opal_prd_probe,
437	.remove = opal_prd_remove,
438	};
439
440	module_platform_driver(opal_prd_driver);
441
442	MODULE_DEVICE_TABLE(of, opal_prd_match);
443	MODULE_DESCRIPTION("PowerNV OPAL runtime diagnostic driver");
444	MODULE_LICENSE("GPL");