1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ISH-TP client driver for ISH firmware loading
4  *
5  * Copyright (c) 2019, Intel Corporation.
6  */
7 
8 #include <linux/firmware.h>
9 #include <linux/module.h>
10 #include <linux/pci.h>
11 #include <linux/intel-ish-client-if.h>
12 #include <linux/property.h>
13 #include <asm/cacheflush.h>
14 
15 /* Number of times we attempt to load the firmware before giving up */
16 #define MAX_LOAD_ATTEMPTS			3
17 
18 /* ISH TX/RX ring buffer pool size */
19 #define LOADER_CL_RX_RING_SIZE			1
20 #define LOADER_CL_TX_RING_SIZE			1
21 
22 /*
23  * ISH Shim firmware loader reserves 4 Kb buffer in SRAM. The buffer is
24  * used to temporarily hold the data transferred from host to Shim
25  * firmware loader. Reason for the odd size of 3968 bytes? Each IPC
26  * transfer is 128 bytes (= 4 bytes header + 124 bytes payload). So the
27  * 4 Kb buffer can hold maximum of 32 IPC transfers, which means we can
28  * have a max payload of 3968 bytes (= 32 x 124 payload).
29  */
30 #define LOADER_SHIM_IPC_BUF_SIZE		3968
31 
32 /**
33  * enum ish_loader_commands -	ISH loader host commands.
34  * @LOADER_CMD_XFER_QUERY:	Query the Shim firmware loader for
35  *				capabilities
36  * @LOADER_CMD_XFER_FRAGMENT:	Transfer one firmware image fragment at a
37  *				time. The command may be executed
38  *				multiple times until the entire firmware
39  *				image is downloaded to SRAM.
40  * @LOADER_CMD_START:		Start executing the main firmware.
41  */
42 enum ish_loader_commands {
43 	LOADER_CMD_XFER_QUERY = 0,
44 	LOADER_CMD_XFER_FRAGMENT,
45 	LOADER_CMD_START,
46 };
47 
48 /* Command bit mask */
49 #define	CMD_MASK				GENMASK(6, 0)
50 #define	IS_RESPONSE				BIT(7)
51 
52 /*
53  * ISH firmware max delay for one transmit failure is 1 Hz,
54  * and firmware will retry 2 times, so 3 Hz is used for timeout.
55  */
56 #define ISHTP_SEND_TIMEOUT			(3 * HZ)
57 
58 /*
59  * Loader transfer modes:
60  *
61  * LOADER_XFER_MODE_ISHTP mode uses the existing ISH-TP mechanism to
62  * transfer data. This may use IPC or DMA if supported in firmware.
63  * The buffer size is limited to 4 Kb by the IPC/ISH-TP protocol for
64  * both IPC & DMA (legacy).
65  *
66  * LOADER_XFER_MODE_DIRECT_DMA - firmware loading is a bit different
67  * from the sensor data streaming. Here we download a large (300+ Kb)
68  * image directly to ISH SRAM memory. There is limited benefit of
69  * DMA'ing 300 Kb image in 4 Kb chucks limit. Hence, we introduce
70  * this "direct dma" mode, where we do not use ISH-TP for DMA, but
71  * instead manage the DMA directly in kernel driver and Shim firmware
72  * loader (allocate buffer, break in chucks and transfer). This allows
73  * to overcome 4 Kb limit, and optimize the data flow path in firmware.
74  */
75 #define LOADER_XFER_MODE_DIRECT_DMA		BIT(0)
76 #define LOADER_XFER_MODE_ISHTP			BIT(1)
77 
78 /* ISH Transport Loader client unique GUID */
79 static const struct ishtp_device_id loader_ishtp_id_table[] = {
80 	{ .guid = GUID_INIT(0xc804d06a, 0x55bd, 0x4ea7,
81 		  0xad, 0xed, 0x1e, 0x31, 0x22, 0x8c, 0x76, 0xdc) },
82 	{ }
83 };
84 MODULE_DEVICE_TABLE(ishtp, loader_ishtp_id_table);
85 
86 #define FILENAME_SIZE				256
87 
88 /*
89  * The firmware loading latency will be minimum if we can DMA the
90  * entire ISH firmware image in one go. This requires that we allocate
91  * a large DMA buffer in kernel, which could be problematic on some
92  * platforms. So here we limit the DMA buffer size via a module_param.
93  * We default to 4 pages, but a customer can set it to higher limit if
94  * deemed appropriate for his platform.
95  */
96 static int dma_buf_size_limit = 4 * PAGE_SIZE;
97 
98 /**
99  * struct loader_msg_hdr - Header for ISH Loader commands.
100  * @command:		LOADER_CMD* commands. Bit 7 is the response.
101  * @reserved:		Reserved space
102  * @status:		Command response status. Non 0, is error
103  *			condition.
104  *
105  * This structure is used as header for every command/data sent/received
106  * between Host driver and ISH Shim firmware loader.
107  */
108 struct loader_msg_hdr {
109 	u8 command;
110 	u8 reserved[2];
111 	u8 status;
112 } __packed;
113 
114 struct loader_xfer_query {
115 	struct loader_msg_hdr hdr;
116 	u32 image_size;
117 } __packed;
118 
119 struct ish_fw_version {
120 	u16 major;
121 	u16 minor;
122 	u16 hotfix;
123 	u16 build;
124 } __packed;
125 
126 union loader_version {
127 	u32 value;
128 	struct {
129 		u8 major;
130 		u8 minor;
131 		u8 hotfix;
132 		u8 build;
133 	};
134 } __packed;
135 
136 struct loader_capability {
137 	u32 max_fw_image_size;
138 	u32 xfer_mode;
139 	u32 max_dma_buf_size; /* only for dma mode, multiples of cacheline */
140 } __packed;
141 
142 struct shim_fw_info {
143 	struct ish_fw_version ish_fw_version;
144 	u32 protocol_version;
145 	union loader_version ldr_version;
146 	struct loader_capability ldr_capability;
147 } __packed;
148 
149 struct loader_xfer_query_response {
150 	struct loader_msg_hdr hdr;
151 	struct shim_fw_info fw_info;
152 } __packed;
153 
154 struct loader_xfer_fragment {
155 	struct loader_msg_hdr hdr;
156 	u32 xfer_mode;
157 	u32 offset;
158 	u32 size;
159 	u32 is_last;
160 } __packed;
161 
162 struct loader_xfer_ipc_fragment {
163 	struct loader_xfer_fragment fragment;
164 	u8 data[] ____cacheline_aligned; /* variable length payload here */
165 } __packed;
166 
167 struct loader_xfer_dma_fragment {
168 	struct loader_xfer_fragment fragment;
169 	u64 ddr_phys_addr;
170 } __packed;
171 
172 struct loader_start {
173 	struct loader_msg_hdr hdr;
174 } __packed;
175 
176 /**
177  * struct response_info - Encapsulate firmware response related
178  *			information for passing between function
179  *			loader_cl_send() and process_recv() callback.
180  * @data:		Copy the data received from firmware here.
181  * @max_size:		Max size allocated for the @data buffer. If the
182  *			received data exceeds this value, we log an
183  *			error.
184  * @size:		Actual size of data received from firmware.
185  * @error:		Returns 0 for success, negative error code for a
186  *			failure in function process_recv().
187  * @received:		Set to true on receiving a valid firmware
188  *			response to host command
189  * @wait_queue:		Wait queue for Host firmware loading where the
190  *			client sends message to ISH firmware and waits
191  *			for response
192  */
193 struct response_info {
194 	void *data;
195 	size_t max_size;
196 	size_t size;
197 	int error;
198 	bool received;
199 	wait_queue_head_t wait_queue;
200 };
201 
202 /*
203  * struct ishtp_cl_data - Encapsulate per ISH-TP Client Data.
204  * @work_ishtp_reset:	Work queue for reset handling.
205  * @work_fw_load:	Work queue for host firmware loading.
206  * @flag_retry:		Flag for indicating host firmware loading should
207  *			be retried.
208  * @retry_count:	Count the number of retries.
209  *
210  * This structure is used to store data per client.
211  */
212 struct ishtp_cl_data {
213 	struct ishtp_cl *loader_ishtp_cl;
214 	struct ishtp_cl_device *cl_device;
215 
216 	/*
217 	 * Used for passing firmware response information between
218 	 * loader_cl_send() and process_recv() callback.
219 	 */
220 	struct response_info response;
221 
222 	struct work_struct work_ishtp_reset;
223 	struct work_struct work_fw_load;
224 
225 	/*
226 	 * In certain failure scenrios, it makes sense to reset the ISH
227 	 * subsystem and retry Host firmware loading (e.g. bad message
228 	 * packet, ENOMEM, etc.). On the other hand, failures due to
229 	 * protocol mismatch, etc., are not recoverable. We do not
230 	 * retry them.
231 	 *
232 	 * If set, the flag indicates that we should re-try the
233 	 * particular failure.
234 	 */
235 	bool flag_retry;
236 	int retry_count;
237 };
238 
239 #define IPC_FRAGMENT_DATA_PREAMBLE				\
240 	offsetof(struct loader_xfer_ipc_fragment, data)
241 
242 #define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
243 
244 /**
245  * get_firmware_variant() - Gets the filename of firmware image to be
246  *			loaded based on platform variant.
247  * @client_data:	Client data instance.
248  * @filename:		Returns firmware filename.
249  *
250  * Queries the firmware-name device property string.
251  *
252  * Return: 0 for success, negative error code for failure.
253  */
254 static int get_firmware_variant(struct ishtp_cl_data *client_data,
255 				char *filename)
256 {
257 	int rv;
258 	const char *val;
259 	struct device *devc = ishtp_get_pci_device(client_data->cl_device);
260 
261 	rv = device_property_read_string(devc, "firmware-name", &val);
262 	if (rv < 0) {
263 		dev_err(devc,
264 			"Error: ISH firmware-name device property required\n");
265 		return rv;
266 	}
267 	return snprintf(filename, FILENAME_SIZE, "intel/%s", val);
268 }
269 
270 /**
271  * loader_cl_send()	Send message from host to firmware
272  * @client_data:	Client data instance
273  * @out_msg:		Message buffer to be sent to firmware
274  * @out_size:		Size of out going message
275  * @in_msg:		Message buffer where the incoming data copied.
276  *			This buffer is allocated by calling
277  * @in_size:		Max size of incoming message
278  *
279  * Return: Number of bytes copied in the in_msg on success, negative
280  * error code on failure.
281  */
282 static int loader_cl_send(struct ishtp_cl_data *client_data,
283 			  u8 *out_msg, size_t out_size,
284 			  u8 *in_msg, size_t in_size)
285 {
286 	int rv;
287 	struct loader_msg_hdr *out_hdr = (struct loader_msg_hdr *)out_msg;
288 	struct ishtp_cl *loader_ishtp_cl = client_data->loader_ishtp_cl;
289 
290 	dev_dbg(cl_data_to_dev(client_data),
291 		"%s: command=%02lx is_response=%u status=%02x\n",
292 		__func__,
293 		out_hdr->command & CMD_MASK,
294 		out_hdr->command & IS_RESPONSE ? 1 : 0,
295 		out_hdr->status);
296 
297 	/* Setup in coming buffer & size */
298 	client_data->response.data = in_msg;
299 	client_data->response.max_size = in_size;
300 	client_data->response.error = 0;
301 	client_data->response.received = false;
302 
303 	rv = ishtp_cl_send(loader_ishtp_cl, out_msg, out_size);
304 	if (rv < 0) {
305 		dev_err(cl_data_to_dev(client_data),
306 			"ishtp_cl_send error %d\n", rv);
307 		return rv;
308 	}
309 
310 	wait_event_interruptible_timeout(client_data->response.wait_queue,
311 					 client_data->response.received,
312 					 ISHTP_SEND_TIMEOUT);
313 	if (!client_data->response.received) {
314 		dev_err(cl_data_to_dev(client_data),
315 			"Timed out for response to command=%02lx",
316 			out_hdr->command & CMD_MASK);
317 		return -ETIMEDOUT;
318 	}
319 
320 	if (client_data->response.error < 0)
321 		return client_data->response.error;
322 
323 	return client_data->response.size;
324 }
325 
326 /**
327  * process_recv() -	Receive and parse incoming packet
328  * @loader_ishtp_cl:	Client instance to get stats
329  * @rb_in_proc:		ISH received message buffer
330  *
331  * Parse the incoming packet. If it is a response packet then it will
332  * update received and wake up the caller waiting to for the response.
333  */
334 static void process_recv(struct ishtp_cl *loader_ishtp_cl,
335 			 struct ishtp_cl_rb *rb_in_proc)
336 {
337 	struct loader_msg_hdr *hdr;
338 	size_t data_len = rb_in_proc->buf_idx;
339 	struct ishtp_cl_data *client_data =
340 		ishtp_get_client_data(loader_ishtp_cl);
341 
342 	/* Sanity check */
343 	if (!client_data->response.data) {
344 		dev_err(cl_data_to_dev(client_data),
345 			"Receiving buffer is null. Should be allocated by calling function\n");
346 		client_data->response.error = -EINVAL;
347 		goto end;
348 	}
349 
350 	if (client_data->response.received) {
351 		dev_err(cl_data_to_dev(client_data),
352 			"Previous firmware message not yet processed\n");
353 		client_data->response.error = -EINVAL;
354 		goto end;
355 	}
356 	/*
357 	 * All firmware messages have a header. Check buffer size
358 	 * before accessing elements inside.
359 	 */
360 	if (!rb_in_proc->buffer.data) {
361 		dev_warn(cl_data_to_dev(client_data),
362 			 "rb_in_proc->buffer.data returned null");
363 		client_data->response.error = -EBADMSG;
364 		goto end;
365 	}
366 
367 	if (data_len < sizeof(struct loader_msg_hdr)) {
368 		dev_err(cl_data_to_dev(client_data),
369 			"data size %zu is less than header %zu\n",
370 			data_len, sizeof(struct loader_msg_hdr));
371 		client_data->response.error = -EMSGSIZE;
372 		goto end;
373 	}
374 
375 	hdr = (struct loader_msg_hdr *)rb_in_proc->buffer.data;
376 
377 	dev_dbg(cl_data_to_dev(client_data),
378 		"%s: command=%02lx is_response=%u status=%02x\n",
379 		__func__,
380 		hdr->command & CMD_MASK,
381 		hdr->command & IS_RESPONSE ? 1 : 0,
382 		hdr->status);
383 
384 	if (((hdr->command & CMD_MASK) != LOADER_CMD_XFER_QUERY) &&
385 	    ((hdr->command & CMD_MASK) != LOADER_CMD_XFER_FRAGMENT) &&
386 	    ((hdr->command & CMD_MASK) != LOADER_CMD_START)) {
387 		dev_err(cl_data_to_dev(client_data),
388 			"Invalid command=%02lx\n",
389 			hdr->command & CMD_MASK);
390 		client_data->response.error = -EPROTO;
391 		goto end;
392 	}
393 
394 	if (data_len > client_data->response.max_size) {
395 		dev_err(cl_data_to_dev(client_data),
396 			"Received buffer size %zu is larger than allocated buffer %zu\n",
397 			data_len, client_data->response.max_size);
398 		client_data->response.error = -EMSGSIZE;
399 		goto end;
400 	}
401 
402 	/* We expect only "response" messages from firmware */
403 	if (!(hdr->command & IS_RESPONSE)) {
404 		dev_err(cl_data_to_dev(client_data),
405 			"Invalid response to command\n");
406 		client_data->response.error = -EIO;
407 		goto end;
408 	}
409 
410 	if (hdr->status) {
411 		dev_err(cl_data_to_dev(client_data),
412 			"Loader returned status %d\n",
413 			hdr->status);
414 		client_data->response.error = -EIO;
415 		goto end;
416 	}
417 
418 	/* Update the actual received buffer size */
419 	client_data->response.size = data_len;
420 
421 	/*
422 	 * Copy the buffer received in firmware response for the
423 	 * calling thread.
424 	 */
425 	memcpy(client_data->response.data,
426 	       rb_in_proc->buffer.data, data_len);
427 
428 	/* Set flag before waking up the caller */
429 	client_data->response.received = true;
430 
431 end:
432 	/* Free the buffer */
433 	ishtp_cl_io_rb_recycle(rb_in_proc);
434 	rb_in_proc = NULL;
435 
436 	/* Wake the calling thread */
437 	wake_up_interruptible(&client_data->response.wait_queue);
438 }
439 
440 /**
441  * loader_cl_event_cb() - bus driver callback for incoming message
442  * @cl_device:		Pointer to the ishtp client device for which this
443  *			message is targeted
444  *
445  * Remove the packet from the list and process the message by calling
446  * process_recv
447  */
448 static void loader_cl_event_cb(struct ishtp_cl_device *cl_device)
449 {
450 	struct ishtp_cl_rb *rb_in_proc;
451 	struct ishtp_cl	*loader_ishtp_cl = ishtp_get_drvdata(cl_device);
452 
453 	while ((rb_in_proc = ishtp_cl_rx_get_rb(loader_ishtp_cl)) != NULL) {
454 		/* Process the data packet from firmware */
455 		process_recv(loader_ishtp_cl, rb_in_proc);
456 	}
457 }
458 
459 /**
460  * ish_query_loader_prop() -  Query ISH Shim firmware loader
461  * @client_data:	Client data instance
462  * @fw:			Pointer to firmware data struct in host memory
463  * @fw_info:		Loader firmware properties
464  *
465  * This function queries the ISH Shim firmware loader for capabilities.
466  *
467  * Return: 0 for success, negative error code for failure.
468  */
469 static int ish_query_loader_prop(struct ishtp_cl_data *client_data,
470 				 const struct firmware *fw,
471 				 struct shim_fw_info *fw_info)
472 {
473 	int rv;
474 	struct loader_xfer_query ldr_xfer_query;
475 	struct loader_xfer_query_response ldr_xfer_query_resp;
476 
477 	memset(&ldr_xfer_query, 0, sizeof(ldr_xfer_query));
478 	ldr_xfer_query.hdr.command = LOADER_CMD_XFER_QUERY;
479 	ldr_xfer_query.image_size = fw->size;
480 	rv = loader_cl_send(client_data,
481 			    (u8 *)&ldr_xfer_query,
482 			    sizeof(ldr_xfer_query),
483 			    (u8 *)&ldr_xfer_query_resp,
484 			    sizeof(ldr_xfer_query_resp));
485 	if (rv < 0) {
486 		client_data->flag_retry = true;
487 		*fw_info = (struct shim_fw_info){};
488 		return rv;
489 	}
490 
491 	/* On success, the return value is the received buffer size */
492 	if (rv != sizeof(struct loader_xfer_query_response)) {
493 		dev_err(cl_data_to_dev(client_data),
494 			"data size %d is not equal to size of loader_xfer_query_response %zu\n",
495 			rv, sizeof(struct loader_xfer_query_response));
496 		client_data->flag_retry = true;
497 		*fw_info = (struct shim_fw_info){};
498 		return -EMSGSIZE;
499 	}
500 
501 	/* Save fw_info for use outside this function */
502 	*fw_info = ldr_xfer_query_resp.fw_info;
503 
504 	/* Loader firmware properties */
505 	dev_dbg(cl_data_to_dev(client_data),
506 		"ish_fw_version: major=%d minor=%d hotfix=%d build=%d protocol_version=0x%x loader_version=%d\n",
507 		fw_info->ish_fw_version.major,
508 		fw_info->ish_fw_version.minor,
509 		fw_info->ish_fw_version.hotfix,
510 		fw_info->ish_fw_version.build,
511 		fw_info->protocol_version,
512 		fw_info->ldr_version.value);
513 
514 	dev_dbg(cl_data_to_dev(client_data),
515 		"loader_capability: max_fw_image_size=0x%x xfer_mode=%d max_dma_buf_size=0x%x dma_buf_size_limit=0x%x\n",
516 		fw_info->ldr_capability.max_fw_image_size,
517 		fw_info->ldr_capability.xfer_mode,
518 		fw_info->ldr_capability.max_dma_buf_size,
519 		dma_buf_size_limit);
520 
521 	/* Sanity checks */
522 	if (fw_info->ldr_capability.max_fw_image_size < fw->size) {
523 		dev_err(cl_data_to_dev(client_data),
524 			"ISH firmware size %zu is greater than Shim firmware loader max supported %d\n",
525 			fw->size,
526 			fw_info->ldr_capability.max_fw_image_size);
527 		return -ENOSPC;
528 	}
529 
530 	/* For DMA the buffer size should be multiple of cacheline size */
531 	if ((fw_info->ldr_capability.xfer_mode & LOADER_XFER_MODE_DIRECT_DMA) &&
532 	    (fw_info->ldr_capability.max_dma_buf_size % L1_CACHE_BYTES)) {
533 		dev_err(cl_data_to_dev(client_data),
534 			"Shim firmware loader buffer size %d should be multiple of cacheline\n",
535 			fw_info->ldr_capability.max_dma_buf_size);
536 		return -EINVAL;
537 	}
538 
539 	return 0;
540 }
541 
542 /**
543  * ish_fw_xfer_ishtp() - Loads ISH firmware using ishtp interface
544  * @client_data:	Client data instance
545  * @fw:			Pointer to firmware data struct in host memory
546  *
547  * This function uses ISH-TP to transfer ISH firmware from host to
548  * ISH SRAM. Lower layers may use IPC or DMA depending on firmware
549  * support.
550  *
551  * Return: 0 for success, negative error code for failure.
552  */
553 static int ish_fw_xfer_ishtp(struct ishtp_cl_data *client_data,
554 			     const struct firmware *fw)
555 {
556 	int rv;
557 	u32 fragment_offset, fragment_size, payload_max_size;
558 	struct loader_xfer_ipc_fragment *ldr_xfer_ipc_frag;
559 	struct loader_msg_hdr ldr_xfer_ipc_ack;
560 
561 	payload_max_size =
562 		LOADER_SHIM_IPC_BUF_SIZE - IPC_FRAGMENT_DATA_PREAMBLE;
563 
564 	ldr_xfer_ipc_frag = kzalloc(LOADER_SHIM_IPC_BUF_SIZE, GFP_KERNEL);
565 	if (!ldr_xfer_ipc_frag) {
566 		client_data->flag_retry = true;
567 		return -ENOMEM;
568 	}
569 
570 	ldr_xfer_ipc_frag->fragment.hdr.command = LOADER_CMD_XFER_FRAGMENT;
571 	ldr_xfer_ipc_frag->fragment.xfer_mode = LOADER_XFER_MODE_ISHTP;
572 
573 	/* Break the firmware image into fragments and send as ISH-TP payload */
574 	fragment_offset = 0;
575 	while (fragment_offset < fw->size) {
576 		if (fragment_offset + payload_max_size < fw->size) {
577 			fragment_size = payload_max_size;
578 			ldr_xfer_ipc_frag->fragment.is_last = 0;
579 		} else {
580 			fragment_size = fw->size - fragment_offset;
581 			ldr_xfer_ipc_frag->fragment.is_last = 1;
582 		}
583 
584 		ldr_xfer_ipc_frag->fragment.offset = fragment_offset;
585 		ldr_xfer_ipc_frag->fragment.size = fragment_size;
586 		memcpy(ldr_xfer_ipc_frag->data,
587 		       &fw->data[fragment_offset],
588 		       fragment_size);
589 
590 		dev_dbg(cl_data_to_dev(client_data),
591 			"xfer_mode=ipc offset=0x%08x size=0x%08x is_last=%d\n",
592 			ldr_xfer_ipc_frag->fragment.offset,
593 			ldr_xfer_ipc_frag->fragment.size,
594 			ldr_xfer_ipc_frag->fragment.is_last);
595 
596 		rv = loader_cl_send(client_data,
597 				    (u8 *)ldr_xfer_ipc_frag,
598 				    IPC_FRAGMENT_DATA_PREAMBLE + fragment_size,
599 				    (u8 *)&ldr_xfer_ipc_ack,
600 				    sizeof(ldr_xfer_ipc_ack));
601 		if (rv < 0) {
602 			client_data->flag_retry = true;
603 			goto end_err_resp_buf_release;
604 		}
605 
606 		fragment_offset += fragment_size;
607 	}
608 
609 	kfree(ldr_xfer_ipc_frag);
610 	return 0;
611 
612 end_err_resp_buf_release:
613 	/* Free ISH buffer if not done already, in error case */
614 	kfree(ldr_xfer_ipc_frag);
615 	return rv;
616 }
617 
618 /**
619  * ish_fw_xfer_direct_dma() - Loads ISH firmware using direct dma
620  * @client_data:	Client data instance
621  * @fw:			Pointer to firmware data struct in host memory
622  * @fw_info:		Loader firmware properties
623  *
624  * Host firmware load is a unique case where we need to download
625  * a large firmware image (200+ Kb). This function implements
626  * direct DMA transfer in kernel and ISH firmware. This allows
627  * us to overcome the ISH-TP 4 Kb limit, and allows us to DMA
628  * directly to ISH UMA at location of choice.
629  * Function depends on corresponding support in ISH firmware.
630  *
631  * Return: 0 for success, negative error code for failure.
632  */
633 static int ish_fw_xfer_direct_dma(struct ishtp_cl_data *client_data,
634 				  const struct firmware *fw,
635 				  const struct shim_fw_info fw_info)
636 {
637 	int rv;
638 	void *dma_buf;
639 	dma_addr_t dma_buf_phy;
640 	u32 fragment_offset, fragment_size, payload_max_size;
641 	struct loader_msg_hdr ldr_xfer_dma_frag_ack;
642 	struct loader_xfer_dma_fragment ldr_xfer_dma_frag;
643 	struct device *devc = ishtp_get_pci_device(client_data->cl_device);
644 	u32 shim_fw_buf_size =
645 		fw_info.ldr_capability.max_dma_buf_size;
646 
647 	/*
648 	 * payload_max_size should be set to minimum of
649 	 *  (1) Size of firmware to be loaded,
650 	 *  (2) Max DMA buffer size supported by Shim firmware,
651 	 *  (3) DMA buffer size limit set by boot_param dma_buf_size_limit.
652 	 */
653 	payload_max_size = min3(fw->size,
654 				(size_t)shim_fw_buf_size,
655 				(size_t)dma_buf_size_limit);
656 
657 	/*
658 	 * Buffer size should be multiple of cacheline size
659 	 * if it's not, select the previous cacheline boundary.
660 	 */
661 	payload_max_size &= ~(L1_CACHE_BYTES - 1);
662 
663 	dma_buf = kmalloc(payload_max_size, GFP_KERNEL | GFP_DMA32);
664 	if (!dma_buf) {
665 		client_data->flag_retry = true;
666 		return -ENOMEM;
667 	}
668 
669 	dma_buf_phy = dma_map_single(devc, dma_buf, payload_max_size,
670 				     DMA_TO_DEVICE);
671 	if (dma_mapping_error(devc, dma_buf_phy)) {
672 		dev_err(cl_data_to_dev(client_data), "DMA map failed\n");
673 		client_data->flag_retry = true;
674 		rv = -ENOMEM;
675 		goto end_err_dma_buf_release;
676 	}
677 
678 	ldr_xfer_dma_frag.fragment.hdr.command = LOADER_CMD_XFER_FRAGMENT;
679 	ldr_xfer_dma_frag.fragment.xfer_mode = LOADER_XFER_MODE_DIRECT_DMA;
680 	ldr_xfer_dma_frag.ddr_phys_addr = (u64)dma_buf_phy;
681 
682 	/* Send the firmware image in chucks of payload_max_size */
683 	fragment_offset = 0;
684 	while (fragment_offset < fw->size) {
685 		if (fragment_offset + payload_max_size < fw->size) {
686 			fragment_size = payload_max_size;
687 			ldr_xfer_dma_frag.fragment.is_last = 0;
688 		} else {
689 			fragment_size = fw->size - fragment_offset;
690 			ldr_xfer_dma_frag.fragment.is_last = 1;
691 		}
692 
693 		ldr_xfer_dma_frag.fragment.offset = fragment_offset;
694 		ldr_xfer_dma_frag.fragment.size = fragment_size;
695 		memcpy(dma_buf, &fw->data[fragment_offset], fragment_size);
696 
697 		dma_sync_single_for_device(devc, dma_buf_phy,
698 					   payload_max_size,
699 					   DMA_TO_DEVICE);
700 
701 		/*
702 		 * Flush cache here because the dma_sync_single_for_device()
703 		 * does not do for x86.
704 		 */
705 		clflush_cache_range(dma_buf, payload_max_size);
706 
707 		dev_dbg(cl_data_to_dev(client_data),
708 			"xfer_mode=dma offset=0x%08x size=0x%x is_last=%d ddr_phys_addr=0x%016llx\n",
709 			ldr_xfer_dma_frag.fragment.offset,
710 			ldr_xfer_dma_frag.fragment.size,
711 			ldr_xfer_dma_frag.fragment.is_last,
712 			ldr_xfer_dma_frag.ddr_phys_addr);
713 
714 		rv = loader_cl_send(client_data,
715 				    (u8 *)&ldr_xfer_dma_frag,
716 				    sizeof(ldr_xfer_dma_frag),
717 				    (u8 *)&ldr_xfer_dma_frag_ack,
718 				    sizeof(ldr_xfer_dma_frag_ack));
719 		if (rv < 0) {
720 			client_data->flag_retry = true;
721 			goto end_err_resp_buf_release;
722 		}
723 
724 		fragment_offset += fragment_size;
725 	}
726 
727 	dma_unmap_single(devc, dma_buf_phy, payload_max_size, DMA_TO_DEVICE);
728 	kfree(dma_buf);
729 	return 0;
730 
731 end_err_resp_buf_release:
732 	/* Free ISH buffer if not done already, in error case */
733 	dma_unmap_single(devc, dma_buf_phy, payload_max_size, DMA_TO_DEVICE);
734 end_err_dma_buf_release:
735 	kfree(dma_buf);
736 	return rv;
737 }
738 
739 /**
740  * ish_fw_start() -	Start executing ISH main firmware
741  * @client_data:	client data instance
742  *
743  * This function sends message to Shim firmware loader to start
744  * the execution of ISH main firmware.
745  *
746  * Return: 0 for success, negative error code for failure.
747  */
748 static int ish_fw_start(struct ishtp_cl_data *client_data)
749 {
750 	struct loader_start ldr_start;
751 	struct loader_msg_hdr ldr_start_ack;
752 
753 	memset(&ldr_start, 0, sizeof(ldr_start));
754 	ldr_start.hdr.command = LOADER_CMD_START;
755 	return loader_cl_send(client_data,
756 			    (u8 *)&ldr_start,
757 			    sizeof(ldr_start),
758 			    (u8 *)&ldr_start_ack,
759 			    sizeof(ldr_start_ack));
760 }
761 
762 /**
763  * load_fw_from_host() - Loads ISH firmware from host
764  * @client_data:	Client data instance
765  *
766  * This function loads the ISH firmware to ISH SRAM and starts execution
767  *
768  * Return: 0 for success, negative error code for failure.
769  */
770 static int load_fw_from_host(struct ishtp_cl_data *client_data)
771 {
772 	int rv;
773 	u32 xfer_mode;
774 	char *filename;
775 	const struct firmware *fw;
776 	struct shim_fw_info fw_info;
777 	struct ishtp_cl *loader_ishtp_cl = client_data->loader_ishtp_cl;
778 
779 	client_data->flag_retry = false;
780 
781 	filename = kzalloc(FILENAME_SIZE, GFP_KERNEL);
782 	if (!filename) {
783 		client_data->flag_retry = true;
784 		rv = -ENOMEM;
785 		goto end_error;
786 	}
787 
788 	/* Get filename of the ISH firmware to be loaded */
789 	rv = get_firmware_variant(client_data, filename);
790 	if (rv < 0)
791 		goto end_err_filename_buf_release;
792 
793 	rv = request_firmware(&fw, filename, cl_data_to_dev(client_data));
794 	if (rv < 0)
795 		goto end_err_filename_buf_release;
796 
797 	/* Step 1: Query Shim firmware loader properties */
798 
799 	rv = ish_query_loader_prop(client_data, fw, &fw_info);
800 	if (rv < 0)
801 		goto end_err_fw_release;
802 
803 	/* Step 2: Send the main firmware image to be loaded, to ISH SRAM */
804 
805 	xfer_mode = fw_info.ldr_capability.xfer_mode;
806 	if (xfer_mode & LOADER_XFER_MODE_DIRECT_DMA) {
807 		rv = ish_fw_xfer_direct_dma(client_data, fw, fw_info);
808 	} else if (xfer_mode & LOADER_XFER_MODE_ISHTP) {
809 		rv = ish_fw_xfer_ishtp(client_data, fw);
810 	} else {
811 		dev_err(cl_data_to_dev(client_data),
812 			"No transfer mode selected in firmware\n");
813 		rv = -EINVAL;
814 	}
815 	if (rv < 0)
816 		goto end_err_fw_release;
817 
818 	/* Step 3: Start ISH main firmware exeuction */
819 
820 	rv = ish_fw_start(client_data);
821 	if (rv < 0)
822 		goto end_err_fw_release;
823 
824 	release_firmware(fw);
825 	dev_info(cl_data_to_dev(client_data), "ISH firmware %s loaded\n",
826 		 filename);
827 	kfree(filename);
828 	return 0;
829 
830 end_err_fw_release:
831 	release_firmware(fw);
832 end_err_filename_buf_release:
833 	kfree(filename);
834 end_error:
835 	/* Keep a count of retries, and give up after 3 attempts */
836 	if (client_data->flag_retry &&
837 	    client_data->retry_count++ < MAX_LOAD_ATTEMPTS) {
838 		dev_warn(cl_data_to_dev(client_data),
839 			 "ISH host firmware load failed %d. Resetting ISH, and trying again..\n",
840 			 rv);
841 		ish_hw_reset(ishtp_get_ishtp_device(loader_ishtp_cl));
842 	} else {
843 		dev_err(cl_data_to_dev(client_data),
844 			"ISH host firmware load failed %d\n", rv);
845 	}
846 	return rv;
847 }
848 
849 static void load_fw_from_host_handler(struct work_struct *work)
850 {
851 	struct ishtp_cl_data *client_data;
852 
853 	client_data = container_of(work, struct ishtp_cl_data,
854 				   work_fw_load);
855 	load_fw_from_host(client_data);
856 }
857 
858 /**
859  * loader_init() -	Init function for ISH-TP client
860  * @loader_ishtp_cl:	ISH-TP client instance
861  * @reset:		true if called for init after reset
862  *
863  * Return: 0 for success, negative error code for failure
864  */
865 static int loader_init(struct ishtp_cl *loader_ishtp_cl, int reset)
866 {
867 	int rv;
868 	struct ishtp_fw_client *fw_client;
869 	struct ishtp_cl_data *client_data =
870 		ishtp_get_client_data(loader_ishtp_cl);
871 
872 	dev_dbg(cl_data_to_dev(client_data), "reset flag: %d\n", reset);
873 
874 	rv = ishtp_cl_link(loader_ishtp_cl);
875 	if (rv < 0) {
876 		dev_err(cl_data_to_dev(client_data), "ishtp_cl_link failed\n");
877 		return rv;
878 	}
879 
880 	/* Connect to firmware client */
881 	ishtp_set_tx_ring_size(loader_ishtp_cl, LOADER_CL_TX_RING_SIZE);
882 	ishtp_set_rx_ring_size(loader_ishtp_cl, LOADER_CL_RX_RING_SIZE);
883 
884 	fw_client =
885 		ishtp_fw_cl_get_client(ishtp_get_ishtp_device(loader_ishtp_cl),
886 				       &loader_ishtp_id_table[0].guid);
887 	if (!fw_client) {
888 		dev_err(cl_data_to_dev(client_data),
889 			"ISH client uuid not found\n");
890 		rv = -ENOENT;
891 		goto err_cl_unlink;
892 	}
893 
894 	ishtp_cl_set_fw_client_id(loader_ishtp_cl,
895 				  ishtp_get_fw_client_id(fw_client));
896 	ishtp_set_connection_state(loader_ishtp_cl, ISHTP_CL_CONNECTING);
897 
898 	rv = ishtp_cl_connect(loader_ishtp_cl);
899 	if (rv < 0) {
900 		dev_err(cl_data_to_dev(client_data), "Client connect fail\n");
901 		goto err_cl_unlink;
902 	}
903 
904 	dev_dbg(cl_data_to_dev(client_data), "Client connected\n");
905 
906 	ishtp_register_event_cb(client_data->cl_device, loader_cl_event_cb);
907 
908 	return 0;
909 
910 err_cl_unlink:
911 	ishtp_cl_unlink(loader_ishtp_cl);
912 	return rv;
913 }
914 
915 static void loader_deinit(struct ishtp_cl *loader_ishtp_cl)
916 {
917 	ishtp_set_connection_state(loader_ishtp_cl, ISHTP_CL_DISCONNECTING);
918 	ishtp_cl_disconnect(loader_ishtp_cl);
919 	ishtp_cl_unlink(loader_ishtp_cl);
920 	ishtp_cl_flush_queues(loader_ishtp_cl);
921 
922 	/* Disband and free all Tx and Rx client-level rings */
923 	ishtp_cl_free(loader_ishtp_cl);
924 }
925 
926 static void reset_handler(struct work_struct *work)
927 {
928 	int rv;
929 	struct ishtp_cl_data *client_data;
930 	struct ishtp_cl *loader_ishtp_cl;
931 	struct ishtp_cl_device *cl_device;
932 
933 	client_data = container_of(work, struct ishtp_cl_data,
934 				   work_ishtp_reset);
935 
936 	loader_ishtp_cl = client_data->loader_ishtp_cl;
937 	cl_device = client_data->cl_device;
938 
939 	/* Unlink, flush queues & start again */
940 	ishtp_cl_unlink(loader_ishtp_cl);
941 	ishtp_cl_flush_queues(loader_ishtp_cl);
942 	ishtp_cl_free(loader_ishtp_cl);
943 
944 	loader_ishtp_cl = ishtp_cl_allocate(cl_device);
945 	if (!loader_ishtp_cl)
946 		return;
947 
948 	ishtp_set_drvdata(cl_device, loader_ishtp_cl);
949 	ishtp_set_client_data(loader_ishtp_cl, client_data);
950 	client_data->loader_ishtp_cl = loader_ishtp_cl;
951 	client_data->cl_device = cl_device;
952 
953 	rv = loader_init(loader_ishtp_cl, 1);
954 	if (rv < 0) {
955 		dev_err(ishtp_device(cl_device), "Reset Failed\n");
956 		return;
957 	}
958 
959 	/* ISH firmware loading from host */
960 	load_fw_from_host(client_data);
961 }
962 
963 /**
964  * loader_ishtp_cl_probe() - ISH-TP client driver probe
965  * @cl_device:		ISH-TP client device instance
966  *
967  * This function gets called on device create on ISH-TP bus
968  *
969  * Return: 0 for success, negative error code for failure
970  */
971 static int loader_ishtp_cl_probe(struct ishtp_cl_device *cl_device)
972 {
973 	struct ishtp_cl *loader_ishtp_cl;
974 	struct ishtp_cl_data *client_data;
975 	int rv;
976 
977 	client_data = devm_kzalloc(ishtp_device(cl_device),
978 				   sizeof(*client_data),
979 				   GFP_KERNEL);
980 	if (!client_data)
981 		return -ENOMEM;
982 
983 	loader_ishtp_cl = ishtp_cl_allocate(cl_device);
984 	if (!loader_ishtp_cl)
985 		return -ENOMEM;
986 
987 	ishtp_set_drvdata(cl_device, loader_ishtp_cl);
988 	ishtp_set_client_data(loader_ishtp_cl, client_data);
989 	client_data->loader_ishtp_cl = loader_ishtp_cl;
990 	client_data->cl_device = cl_device;
991 
992 	init_waitqueue_head(&client_data->response.wait_queue);
993 
994 	INIT_WORK(&client_data->work_ishtp_reset,
995 		  reset_handler);
996 	INIT_WORK(&client_data->work_fw_load,
997 		  load_fw_from_host_handler);
998 
999 	rv = loader_init(loader_ishtp_cl, 0);
1000 	if (rv < 0) {
1001 		ishtp_cl_free(loader_ishtp_cl);
1002 		return rv;
1003 	}
1004 	ishtp_get_device(cl_device);
1005 
1006 	client_data->retry_count = 0;
1007 
1008 	/* ISH firmware loading from host */
1009 	schedule_work(&client_data->work_fw_load);
1010 
1011 	return 0;
1012 }
1013 
1014 /**
1015  * loader_ishtp_cl_remove() - ISH-TP client driver remove
1016  * @cl_device:		ISH-TP client device instance
1017  *
1018  * This function gets called on device remove on ISH-TP bus
1019  *
1020  * Return: 0
1021  */
1022 static void loader_ishtp_cl_remove(struct ishtp_cl_device *cl_device)
1023 {
1024 	struct ishtp_cl_data *client_data;
1025 	struct ishtp_cl	*loader_ishtp_cl = ishtp_get_drvdata(cl_device);
1026 
1027 	client_data = ishtp_get_client_data(loader_ishtp_cl);
1028 
1029 	/*
1030 	 * The sequence of the following two cancel_work_sync() is
1031 	 * important. The work_fw_load can in turn schedue
1032 	 * work_ishtp_reset, so first cancel work_fw_load then
1033 	 * cancel work_ishtp_reset.
1034 	 */
1035 	cancel_work_sync(&client_data->work_fw_load);
1036 	cancel_work_sync(&client_data->work_ishtp_reset);
1037 	loader_deinit(loader_ishtp_cl);
1038 	ishtp_put_device(cl_device);
1039 }
1040 
1041 /**
1042  * loader_ishtp_cl_reset() - ISH-TP client driver reset
1043  * @cl_device:		ISH-TP client device instance
1044  *
1045  * This function gets called on device reset on ISH-TP bus
1046  *
1047  * Return: 0
1048  */
1049 static int loader_ishtp_cl_reset(struct ishtp_cl_device *cl_device)
1050 {
1051 	struct ishtp_cl_data *client_data;
1052 	struct ishtp_cl	*loader_ishtp_cl = ishtp_get_drvdata(cl_device);
1053 
1054 	client_data = ishtp_get_client_data(loader_ishtp_cl);
1055 
1056 	schedule_work(&client_data->work_ishtp_reset);
1057 
1058 	return 0;
1059 }
1060 
1061 static struct ishtp_cl_driver	loader_ishtp_cl_driver = {
1062 	.name = "ish-loader",
1063 	.id = loader_ishtp_id_table,
1064 	.probe = loader_ishtp_cl_probe,
1065 	.remove = loader_ishtp_cl_remove,
1066 	.reset = loader_ishtp_cl_reset,
1067 };
1068 
1069 static int __init ish_loader_init(void)
1070 {
1071 	return ishtp_cl_driver_register(&loader_ishtp_cl_driver, THIS_MODULE);
1072 }
1073 
1074 static void __exit ish_loader_exit(void)
1075 {
1076 	ishtp_cl_driver_unregister(&loader_ishtp_cl_driver);
1077 }
1078 
1079 late_initcall(ish_loader_init);
1080 module_exit(ish_loader_exit);
1081 
1082 module_param(dma_buf_size_limit, int, 0644);
1083 MODULE_PARM_DESC(dma_buf_size_limit, "Limit the DMA buf size to this value in bytes");
1084 
1085 MODULE_DESCRIPTION("ISH ISH-TP Host firmware Loader Client Driver");
1086 MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
1087 
1088 MODULE_LICENSE("GPL v2");
1089