xref: /linux/drivers/acpi/pfr_update.c (revision 9bbf8e17d8521211c5c5516ed5ec78d7581aacff)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ACPI Platform Firmware Runtime Update Device driver
4  *
5  * Copyright (C) 2021 Intel Corporation
6  * Author: Chen Yu <yu.c.chen@intel.com>
7  *
8  * pfr_update driver is used for Platform Firmware Runtime
9  * Update, which includes the code injection and driver update.
10  */
11 #include <linux/acpi.h>
12 #include <linux/device.h>
13 #include <linux/efi.h>
14 #include <linux/err.h>
15 #include <linux/errno.h>
16 #include <linux/file.h>
17 #include <linux/fs.h>
18 #include <linux/idr.h>
19 #include <linux/miscdevice.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 #include <linux/string.h>
23 #include <linux/uaccess.h>
24 #include <linux/uio.h>
25 #include <linux/uuid.h>
26 
27 #include <uapi/linux/pfrut.h>
28 
29 #define PFRU_FUNC_STANDARD_QUERY	0
30 #define PFRU_FUNC_QUERY_UPDATE_CAP	1
31 #define PFRU_FUNC_QUERY_BUF		2
32 #define PFRU_FUNC_START		3
33 
34 #define PFRU_CODE_INJECT_TYPE	1
35 #define PFRU_DRIVER_UPDATE_TYPE	2
36 
37 #define PFRU_REVID_1		1
38 #define PFRU_REVID_2		2
39 #define PFRU_DEFAULT_REV_ID	PFRU_REVID_1
40 
41 enum cap_index {
42 	CAP_STATUS_IDX = 0,
43 	CAP_UPDATE_IDX = 1,
44 	CAP_CODE_TYPE_IDX = 2,
45 	CAP_FW_VER_IDX = 3,
46 	CAP_CODE_RT_VER_IDX = 4,
47 	CAP_DRV_TYPE_IDX = 5,
48 	CAP_DRV_RT_VER_IDX = 6,
49 	CAP_DRV_SVN_IDX = 7,
50 	CAP_PLAT_ID_IDX = 8,
51 	CAP_OEM_ID_IDX = 9,
52 	CAP_OEM_INFO_IDX = 10,
53 	CAP_NR_IDX
54 };
55 
56 enum buf_index {
57 	BUF_STATUS_IDX = 0,
58 	BUF_EXT_STATUS_IDX = 1,
59 	BUF_ADDR_LOW_IDX = 2,
60 	BUF_ADDR_HI_IDX = 3,
61 	BUF_SIZE_IDX = 4,
62 	BUF_NR_IDX
63 };
64 
65 enum update_index {
66 	UPDATE_STATUS_IDX = 0,
67 	UPDATE_EXT_STATUS_IDX = 1,
68 	UPDATE_AUTH_TIME_LOW_IDX = 2,
69 	UPDATE_AUTH_TIME_HI_IDX = 3,
70 	UPDATE_EXEC_TIME_LOW_IDX = 4,
71 	UPDATE_EXEC_TIME_HI_IDX = 5,
72 	UPDATE_NR_IDX
73 };
74 
75 enum pfru_start_action {
76 	START_STAGE = 0,
77 	START_ACTIVATE = 1,
78 	START_STAGE_ACTIVATE = 2,
79 };
80 
81 struct pfru_device {
82 	u32 rev_id, index;
83 	struct device *parent_dev;
84 	struct miscdevice miscdev;
85 };
86 
87 static DEFINE_IDA(pfru_ida);
88 
89 /*
90  * Manual reference:
91  * https://uefi.org/sites/default/files/resources/Intel_MM_OS_Interface_Spec_Rev100.pdf
92  *
93  * pfru_guid is the parameter for _DSM method
94  */
95 static const guid_t pfru_guid =
96 	GUID_INIT(0xECF9533B, 0x4A3C, 0x4E89, 0x93, 0x9E, 0xC7, 0x71,
97 		  0x12, 0x60, 0x1C, 0x6D);
98 
99 /* pfru_code_inj_guid is the UUID to identify code injection EFI capsule file */
100 static const guid_t pfru_code_inj_guid =
101 	GUID_INIT(0xB2F84B79, 0x7B6E, 0x4E45, 0x88, 0x5F, 0x3F, 0xB9,
102 		  0xBB, 0x18, 0x54, 0x02);
103 
104 /* pfru_drv_update_guid is the UUID to identify driver update EFI capsule file */
105 static const guid_t pfru_drv_update_guid =
106 	GUID_INIT(0x4569DD8C, 0x75F1, 0x429A, 0xA3, 0xD6, 0x24, 0xDE,
107 		  0x80, 0x97, 0xA0, 0xDF);
108 
pfru_valid_revid(u32 id)109 static inline int pfru_valid_revid(u32 id)
110 {
111 	return id == PFRU_REVID_1 || id == PFRU_REVID_2;
112 }
113 
to_pfru_dev(struct file * file)114 static inline struct pfru_device *to_pfru_dev(struct file *file)
115 {
116 	return container_of(file->private_data, struct pfru_device, miscdev);
117 }
118 
query_capability(struct pfru_update_cap_info * cap_hdr,struct pfru_device * pfru_dev)119 static int query_capability(struct pfru_update_cap_info *cap_hdr,
120 			    struct pfru_device *pfru_dev)
121 {
122 	acpi_handle handle = ACPI_HANDLE(pfru_dev->parent_dev);
123 	union acpi_object *out_obj;
124 	int ret = -EINVAL;
125 
126 	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_guid,
127 					  pfru_dev->rev_id,
128 					  PFRU_FUNC_QUERY_UPDATE_CAP,
129 					  NULL, ACPI_TYPE_PACKAGE);
130 	if (!out_obj) {
131 		dev_dbg(pfru_dev->parent_dev,
132 			"Query cap failed with no object\n");
133 		return ret;
134 	}
135 
136 	if (out_obj->package.count < CAP_NR_IDX ||
137 	    out_obj->package.elements[CAP_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
138 	    out_obj->package.elements[CAP_UPDATE_IDX].type != ACPI_TYPE_INTEGER ||
139 	    out_obj->package.elements[CAP_CODE_TYPE_IDX].type != ACPI_TYPE_BUFFER ||
140 	    out_obj->package.elements[CAP_FW_VER_IDX].type != ACPI_TYPE_INTEGER ||
141 	    out_obj->package.elements[CAP_CODE_RT_VER_IDX].type != ACPI_TYPE_INTEGER ||
142 	    out_obj->package.elements[CAP_DRV_TYPE_IDX].type != ACPI_TYPE_BUFFER ||
143 	    out_obj->package.elements[CAP_DRV_RT_VER_IDX].type != ACPI_TYPE_INTEGER ||
144 	    out_obj->package.elements[CAP_DRV_SVN_IDX].type != ACPI_TYPE_INTEGER ||
145 	    out_obj->package.elements[CAP_PLAT_ID_IDX].type != ACPI_TYPE_BUFFER ||
146 	    out_obj->package.elements[CAP_OEM_ID_IDX].type != ACPI_TYPE_BUFFER ||
147 	    out_obj->package.elements[CAP_OEM_INFO_IDX].type != ACPI_TYPE_BUFFER) {
148 		dev_dbg(pfru_dev->parent_dev,
149 			"Query cap failed with invalid package count/type\n");
150 		goto free_acpi_buffer;
151 	}
152 
153 	cap_hdr->status = out_obj->package.elements[CAP_STATUS_IDX].integer.value;
154 	if (cap_hdr->status != DSM_SUCCEED) {
155 		ret = -EBUSY;
156 		dev_dbg(pfru_dev->parent_dev, "Query cap Error Status:%d\n",
157 			cap_hdr->status);
158 		goto free_acpi_buffer;
159 	}
160 
161 	cap_hdr->update_cap = out_obj->package.elements[CAP_UPDATE_IDX].integer.value;
162 	memcpy(&cap_hdr->code_type,
163 	       out_obj->package.elements[CAP_CODE_TYPE_IDX].buffer.pointer,
164 	       out_obj->package.elements[CAP_CODE_TYPE_IDX].buffer.length);
165 	cap_hdr->fw_version =
166 		out_obj->package.elements[CAP_FW_VER_IDX].integer.value;
167 	cap_hdr->code_rt_version =
168 		out_obj->package.elements[CAP_CODE_RT_VER_IDX].integer.value;
169 	memcpy(&cap_hdr->drv_type,
170 	       out_obj->package.elements[CAP_DRV_TYPE_IDX].buffer.pointer,
171 	       out_obj->package.elements[CAP_DRV_TYPE_IDX].buffer.length);
172 	cap_hdr->drv_rt_version =
173 		out_obj->package.elements[CAP_DRV_RT_VER_IDX].integer.value;
174 	cap_hdr->drv_svn =
175 		out_obj->package.elements[CAP_DRV_SVN_IDX].integer.value;
176 	memcpy(&cap_hdr->platform_id,
177 	       out_obj->package.elements[CAP_PLAT_ID_IDX].buffer.pointer,
178 	       out_obj->package.elements[CAP_PLAT_ID_IDX].buffer.length);
179 	memcpy(&cap_hdr->oem_id,
180 	       out_obj->package.elements[CAP_OEM_ID_IDX].buffer.pointer,
181 	       out_obj->package.elements[CAP_OEM_ID_IDX].buffer.length);
182 	cap_hdr->oem_info_len =
183 		out_obj->package.elements[CAP_OEM_INFO_IDX].buffer.length;
184 
185 	ret = 0;
186 
187 free_acpi_buffer:
188 	ACPI_FREE(out_obj);
189 
190 	return ret;
191 }
192 
query_buffer(struct pfru_com_buf_info * info,struct pfru_device * pfru_dev)193 static int query_buffer(struct pfru_com_buf_info *info,
194 			struct pfru_device *pfru_dev)
195 {
196 	acpi_handle handle = ACPI_HANDLE(pfru_dev->parent_dev);
197 	union acpi_object *out_obj;
198 	int ret = -EINVAL;
199 
200 	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_guid,
201 					  pfru_dev->rev_id, PFRU_FUNC_QUERY_BUF,
202 					  NULL, ACPI_TYPE_PACKAGE);
203 	if (!out_obj) {
204 		dev_dbg(pfru_dev->parent_dev,
205 			"Query buf failed with no object\n");
206 		return ret;
207 	}
208 
209 	if (out_obj->package.count < BUF_NR_IDX ||
210 	    out_obj->package.elements[BUF_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
211 	    out_obj->package.elements[BUF_EXT_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
212 	    out_obj->package.elements[BUF_ADDR_LOW_IDX].type != ACPI_TYPE_INTEGER ||
213 	    out_obj->package.elements[BUF_ADDR_HI_IDX].type != ACPI_TYPE_INTEGER ||
214 	    out_obj->package.elements[BUF_SIZE_IDX].type != ACPI_TYPE_INTEGER) {
215 		dev_dbg(pfru_dev->parent_dev,
216 			"Query buf failed with invalid package count/type\n");
217 		goto free_acpi_buffer;
218 	}
219 
220 	info->status = out_obj->package.elements[BUF_STATUS_IDX].integer.value;
221 	info->ext_status =
222 		out_obj->package.elements[BUF_EXT_STATUS_IDX].integer.value;
223 	if (info->status != DSM_SUCCEED) {
224 		ret = -EBUSY;
225 		dev_dbg(pfru_dev->parent_dev,
226 			"Query buf failed with Error Status:%d\n", info->status);
227 		dev_dbg(pfru_dev->parent_dev,
228 			"Query buf failed with Error Extended Status:%d\n", info->ext_status);
229 
230 		goto free_acpi_buffer;
231 	}
232 
233 	info->addr_lo =
234 		out_obj->package.elements[BUF_ADDR_LOW_IDX].integer.value;
235 	info->addr_hi =
236 		out_obj->package.elements[BUF_ADDR_HI_IDX].integer.value;
237 	info->buf_size = out_obj->package.elements[BUF_SIZE_IDX].integer.value;
238 
239 	ret = 0;
240 
241 free_acpi_buffer:
242 	ACPI_FREE(out_obj);
243 
244 	return ret;
245 }
246 
get_image_type(const struct efi_manage_capsule_image_header * img_hdr,struct pfru_device * pfru_dev)247 static int get_image_type(const struct efi_manage_capsule_image_header *img_hdr,
248 			  struct pfru_device *pfru_dev)
249 {
250 	const efi_guid_t *image_type_id = &img_hdr->image_type_id;
251 
252 	/* check whether this is a code injection or driver update */
253 	if (guid_equal(image_type_id, &pfru_code_inj_guid))
254 		return PFRU_CODE_INJECT_TYPE;
255 
256 	if (guid_equal(image_type_id, &pfru_drv_update_guid))
257 		return PFRU_DRIVER_UPDATE_TYPE;
258 
259 	return -EINVAL;
260 }
261 
adjust_efi_size(const struct efi_manage_capsule_image_header * img_hdr,int size)262 static int adjust_efi_size(const struct efi_manage_capsule_image_header *img_hdr,
263 			   int size)
264 {
265 	/*
266 	 * The (u64 hw_ins) was introduced in UEFI spec version 2,
267 	 * and (u64 capsule_support) was introduced in version 3.
268 	 * The size needs to be adjusted accordingly. That is to
269 	 * say, version 1 should subtract the size of hw_ins+capsule_support,
270 	 * and version 2 should sbstract the size of capsule_support.
271 	 */
272 	size += sizeof(struct efi_manage_capsule_image_header);
273 	switch (img_hdr->ver) {
274 	case 1:
275 		return size - 2 * sizeof(u64);
276 
277 	case 2:
278 		return size - sizeof(u64);
279 
280 	default:
281 		/* only support version 1 and 2 */
282 		return -EINVAL;
283 	}
284 }
285 
applicable_image(const void * data,struct pfru_update_cap_info * cap,struct pfru_device * pfru_dev)286 static bool applicable_image(const void *data, struct pfru_update_cap_info *cap,
287 			     struct pfru_device *pfru_dev)
288 {
289 	struct pfru_payload_hdr *payload_hdr;
290 	const efi_capsule_header_t *cap_hdr = data;
291 	const struct efi_manage_capsule_header *m_hdr;
292 	const struct efi_manage_capsule_image_header *m_img_hdr;
293 	const struct efi_image_auth *auth;
294 	int type, size;
295 
296 	/*
297 	 * If the code in the capsule is older than the current
298 	 * firmware code, the update will be rejected by the firmware,
299 	 * so check the version of it upfront without engaging the
300 	 * Management Mode update mechanism which may be costly.
301 	 */
302 	size = cap_hdr->headersize;
303 	m_hdr = data + size;
304 	/*
305 	 * Current data structure size plus variable array indicated
306 	 * by number of (emb_drv_cnt + payload_cnt)
307 	 */
308 	size += offsetof(struct efi_manage_capsule_header, offset_list) +
309 		(m_hdr->emb_drv_cnt + m_hdr->payload_cnt) * sizeof(u64);
310 	m_img_hdr = data + size;
311 
312 	type = get_image_type(m_img_hdr, pfru_dev);
313 	if (type < 0) {
314 		dev_dbg(pfru_dev->parent_dev, "Invalid image type\n");
315 		return false;
316 	}
317 
318 	size = adjust_efi_size(m_img_hdr, size);
319 	if (size < 0) {
320 		dev_dbg(pfru_dev->parent_dev, "Invalid image size\n");
321 		return false;
322 	}
323 
324 	auth = data + size;
325 	size += sizeof(u64) + auth->auth_info.hdr.len;
326 	payload_hdr = (struct pfru_payload_hdr *)(data + size);
327 
328 	/* finally compare the version */
329 	if (type == PFRU_CODE_INJECT_TYPE)
330 		return payload_hdr->rt_ver >= cap->code_rt_version;
331 
332 	return payload_hdr->rt_ver >= cap->drv_rt_version;
333 }
334 
print_update_debug_info(struct pfru_updated_result * result,struct pfru_device * pfru_dev)335 static void print_update_debug_info(struct pfru_updated_result *result,
336 				    struct pfru_device *pfru_dev)
337 {
338 	dev_dbg(pfru_dev->parent_dev, "Update result:\n");
339 	dev_dbg(pfru_dev->parent_dev, "Authentication Time Low:%lld\n",
340 		result->low_auth_time);
341 	dev_dbg(pfru_dev->parent_dev, "Authentication Time High:%lld\n",
342 		result->high_auth_time);
343 	dev_dbg(pfru_dev->parent_dev, "Execution Time Low:%lld\n",
344 		result->low_exec_time);
345 	dev_dbg(pfru_dev->parent_dev, "Execution Time High:%lld\n",
346 		result->high_exec_time);
347 }
348 
start_update(int action,struct pfru_device * pfru_dev)349 static int start_update(int action, struct pfru_device *pfru_dev)
350 {
351 	union acpi_object *out_obj, in_obj, in_buf;
352 	struct pfru_updated_result update_result;
353 	acpi_handle handle;
354 	int ret = -EINVAL;
355 
356 	memset(&in_obj, 0, sizeof(in_obj));
357 	memset(&in_buf, 0, sizeof(in_buf));
358 	in_obj.type = ACPI_TYPE_PACKAGE;
359 	in_obj.package.count = 1;
360 	in_obj.package.elements = &in_buf;
361 	in_buf.type = ACPI_TYPE_INTEGER;
362 	in_buf.integer.value = action;
363 
364 	handle = ACPI_HANDLE(pfru_dev->parent_dev);
365 	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_guid,
366 					  pfru_dev->rev_id, PFRU_FUNC_START,
367 					  &in_obj, ACPI_TYPE_PACKAGE);
368 	if (!out_obj) {
369 		dev_dbg(pfru_dev->parent_dev,
370 			"Update failed to start with no object\n");
371 		return ret;
372 	}
373 
374 	if (out_obj->package.count < UPDATE_NR_IDX ||
375 	    out_obj->package.elements[UPDATE_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
376 	    out_obj->package.elements[UPDATE_EXT_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
377 	    out_obj->package.elements[UPDATE_AUTH_TIME_LOW_IDX].type != ACPI_TYPE_INTEGER ||
378 	    out_obj->package.elements[UPDATE_AUTH_TIME_HI_IDX].type != ACPI_TYPE_INTEGER ||
379 	    out_obj->package.elements[UPDATE_EXEC_TIME_LOW_IDX].type != ACPI_TYPE_INTEGER ||
380 	    out_obj->package.elements[UPDATE_EXEC_TIME_HI_IDX].type != ACPI_TYPE_INTEGER) {
381 		dev_dbg(pfru_dev->parent_dev,
382 			"Update failed with invalid package count/type\n");
383 		goto free_acpi_buffer;
384 	}
385 
386 	update_result.status =
387 		out_obj->package.elements[UPDATE_STATUS_IDX].integer.value;
388 	update_result.ext_status =
389 		out_obj->package.elements[UPDATE_EXT_STATUS_IDX].integer.value;
390 
391 	if (update_result.status != DSM_SUCCEED) {
392 		ret = -EBUSY;
393 		dev_dbg(pfru_dev->parent_dev,
394 			"Update failed with Error Status:%d\n", update_result.status);
395 		dev_dbg(pfru_dev->parent_dev,
396 			"Update failed with Error Extended Status:%d\n",
397 			update_result.ext_status);
398 
399 		goto free_acpi_buffer;
400 	}
401 
402 	update_result.low_auth_time =
403 		out_obj->package.elements[UPDATE_AUTH_TIME_LOW_IDX].integer.value;
404 	update_result.high_auth_time =
405 		out_obj->package.elements[UPDATE_AUTH_TIME_HI_IDX].integer.value;
406 	update_result.low_exec_time =
407 		out_obj->package.elements[UPDATE_EXEC_TIME_LOW_IDX].integer.value;
408 	update_result.high_exec_time =
409 		out_obj->package.elements[UPDATE_EXEC_TIME_HI_IDX].integer.value;
410 
411 	print_update_debug_info(&update_result, pfru_dev);
412 	ret = 0;
413 
414 free_acpi_buffer:
415 	ACPI_FREE(out_obj);
416 
417 	return ret;
418 }
419 
pfru_ioctl(struct file * file,unsigned int cmd,unsigned long arg)420 static long pfru_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
421 {
422 	struct pfru_update_cap_info cap_hdr;
423 	struct pfru_device *pfru_dev = to_pfru_dev(file);
424 	void __user *p = (void __user *)arg;
425 	u32 rev;
426 	int ret;
427 
428 	switch (cmd) {
429 	case PFRU_IOC_QUERY_CAP:
430 		ret = query_capability(&cap_hdr, pfru_dev);
431 		if (ret)
432 			return ret;
433 
434 		if (copy_to_user(p, &cap_hdr, sizeof(cap_hdr)))
435 			return -EFAULT;
436 
437 		return 0;
438 
439 	case PFRU_IOC_SET_REV:
440 		if (copy_from_user(&rev, p, sizeof(rev)))
441 			return -EFAULT;
442 
443 		if (!pfru_valid_revid(rev))
444 			return -EINVAL;
445 
446 		pfru_dev->rev_id = rev;
447 
448 		return 0;
449 
450 	case PFRU_IOC_STAGE:
451 		return start_update(START_STAGE, pfru_dev);
452 
453 	case PFRU_IOC_ACTIVATE:
454 		return start_update(START_ACTIVATE, pfru_dev);
455 
456 	case PFRU_IOC_STAGE_ACTIVATE:
457 		return start_update(START_STAGE_ACTIVATE, pfru_dev);
458 
459 	default:
460 		return -ENOTTY;
461 	}
462 }
463 
pfru_write(struct file * file,const char __user * buf,size_t len,loff_t * ppos)464 static ssize_t pfru_write(struct file *file, const char __user *buf,
465 			  size_t len, loff_t *ppos)
466 {
467 	struct pfru_device *pfru_dev = to_pfru_dev(file);
468 	struct pfru_update_cap_info cap;
469 	struct pfru_com_buf_info buf_info;
470 	phys_addr_t phy_addr;
471 	struct iov_iter iter;
472 	struct iovec iov;
473 	char *buf_ptr;
474 	int ret;
475 
476 	ret = query_buffer(&buf_info, pfru_dev);
477 	if (ret)
478 		return ret;
479 
480 	if (len > buf_info.buf_size) {
481 		dev_dbg(pfru_dev->parent_dev, "Capsule image size too large\n");
482 		return -EINVAL;
483 	}
484 
485 	iov.iov_base = (void __user *)buf;
486 	iov.iov_len = len;
487 	iov_iter_init(&iter, ITER_SOURCE, &iov, 1, len);
488 
489 	/* map the communication buffer */
490 	phy_addr = (phys_addr_t)((buf_info.addr_hi << 32) | buf_info.addr_lo);
491 	buf_ptr = memremap(phy_addr, buf_info.buf_size, MEMREMAP_WB);
492 	if (!buf_ptr) {
493 		dev_dbg(pfru_dev->parent_dev, "Failed to remap the buffer\n");
494 		return -ENOMEM;
495 	}
496 
497 	if (!copy_from_iter_full(buf_ptr, len, &iter)) {
498 		dev_dbg(pfru_dev->parent_dev,
499 			"Failed to copy the data from the user space buffer\n");
500 		ret = -EINVAL;
501 		goto unmap;
502 	}
503 
504 	/* check if the capsule header has a valid version number */
505 	ret = query_capability(&cap, pfru_dev);
506 	if (ret)
507 		goto unmap;
508 
509 	if (!applicable_image(buf_ptr, &cap, pfru_dev))
510 		ret = -EINVAL;
511 
512 unmap:
513 	memunmap(buf_ptr);
514 
515 	return ret ?: len;
516 }
517 
518 static const struct file_operations acpi_pfru_fops = {
519 	.owner		= THIS_MODULE,
520 	.write		= pfru_write,
521 	.unlocked_ioctl = pfru_ioctl,
522 	.llseek		= noop_llseek,
523 };
524 
acpi_pfru_remove(struct platform_device * pdev)525 static void acpi_pfru_remove(struct platform_device *pdev)
526 {
527 	struct pfru_device *pfru_dev = platform_get_drvdata(pdev);
528 
529 	misc_deregister(&pfru_dev->miscdev);
530 }
531 
pfru_put_idx(void * data)532 static void pfru_put_idx(void *data)
533 {
534 	struct pfru_device *pfru_dev = data;
535 
536 	ida_free(&pfru_ida, pfru_dev->index);
537 }
538 
acpi_pfru_probe(struct platform_device * pdev)539 static int acpi_pfru_probe(struct platform_device *pdev)
540 {
541 	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
542 	struct pfru_device *pfru_dev;
543 	int ret;
544 
545 	if (!acpi_has_method(handle, "_DSM")) {
546 		dev_dbg(&pdev->dev, "Missing _DSM\n");
547 		return -ENODEV;
548 	}
549 
550 	pfru_dev = devm_kzalloc(&pdev->dev, sizeof(*pfru_dev), GFP_KERNEL);
551 	if (!pfru_dev)
552 		return -ENOMEM;
553 
554 	ret = ida_alloc(&pfru_ida, GFP_KERNEL);
555 	if (ret < 0)
556 		return ret;
557 
558 	pfru_dev->index = ret;
559 	ret = devm_add_action_or_reset(&pdev->dev, pfru_put_idx, pfru_dev);
560 	if (ret)
561 		return ret;
562 
563 	pfru_dev->rev_id = PFRU_DEFAULT_REV_ID;
564 	pfru_dev->parent_dev = &pdev->dev;
565 
566 	pfru_dev->miscdev.minor = MISC_DYNAMIC_MINOR;
567 	pfru_dev->miscdev.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
568 						"pfru%d", pfru_dev->index);
569 	if (!pfru_dev->miscdev.name)
570 		return -ENOMEM;
571 
572 	pfru_dev->miscdev.nodename = devm_kasprintf(&pdev->dev, GFP_KERNEL,
573 						    "acpi_pfr_update%d", pfru_dev->index);
574 	if (!pfru_dev->miscdev.nodename)
575 		return -ENOMEM;
576 
577 	pfru_dev->miscdev.fops = &acpi_pfru_fops;
578 	pfru_dev->miscdev.parent = &pdev->dev;
579 
580 	ret = misc_register(&pfru_dev->miscdev);
581 	if (ret)
582 		return ret;
583 
584 	platform_set_drvdata(pdev, pfru_dev);
585 
586 	return 0;
587 }
588 
589 static const struct acpi_device_id acpi_pfru_ids[] = {
590 	{"INTC1080"},
591 	{}
592 };
593 MODULE_DEVICE_TABLE(acpi, acpi_pfru_ids);
594 
595 static struct platform_driver acpi_pfru_driver = {
596 	.driver = {
597 		.name = "pfr_update",
598 		.acpi_match_table = acpi_pfru_ids,
599 	},
600 	.probe = acpi_pfru_probe,
601 	.remove = acpi_pfru_remove,
602 };
603 module_platform_driver(acpi_pfru_driver);
604 
605 MODULE_DESCRIPTION("Platform Firmware Runtime Update device driver");
606 MODULE_LICENSE("GPL v2");
607