xref: /linux/drivers/mailbox/zynqmp-ipi-mailbox.c (revision 68a052239fc4b351e961f698b824f7654a346091)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Xilinx Inter Processor Interrupt(IPI) Mailbox Driver
4  *
5  * Copyright (C) 2018 Xilinx, Inc.
6  */
7 
8 #include <linux/arm-smccc.h>
9 #include <linux/cpuhotplug.h>
10 #include <linux/delay.h>
11 #include <linux/device.h>
12 #include <linux/interrupt.h>
13 #include <linux/irqdomain.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/mailbox_controller.h>
17 #include <linux/mailbox/zynqmp-ipi-message.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/of_irq.h>
22 #include <linux/platform_device.h>
23 
24 /* IPI agent ID any */
25 #define IPI_ID_ANY 0xFFUL
26 
27 /* indicate if ZynqMP IPI mailbox driver uses SMC calls or HVC calls */
28 #define USE_SMC 0
29 #define USE_HVC 1
30 
31 /* Default IPI SMC function IDs */
32 #define SMC_IPI_MAILBOX_OPEN		0x82001000U
33 #define SMC_IPI_MAILBOX_RELEASE		0x82001001U
34 #define SMC_IPI_MAILBOX_STATUS_ENQUIRY	0x82001002U
35 #define SMC_IPI_MAILBOX_NOTIFY		0x82001003U
36 #define SMC_IPI_MAILBOX_ACK		0x82001004U
37 #define SMC_IPI_MAILBOX_ENABLE_IRQ	0x82001005U
38 #define SMC_IPI_MAILBOX_DISABLE_IRQ	0x82001006U
39 
40 /* IPI SMC Macros */
41 #define IPI_SMC_ENQUIRY_DIRQ_MASK	0x00000001UL /* Flag to indicate if
42 						      * notification interrupt
43 						      * to be disabled.
44 						      */
45 #define IPI_SMC_ACK_EIRQ_MASK		0x00000001UL /* Flag to indicate if
46 						      * notification interrupt
47 						      * to be enabled.
48 						      */
49 
50 /* IPI mailbox status */
51 #define IPI_MB_STATUS_IDLE		0
52 #define IPI_MB_STATUS_SEND_PENDING	1
53 #define IPI_MB_STATUS_RECV_PENDING	2
54 
55 #define IPI_MB_CHNL_TX	0 /* IPI mailbox TX channel */
56 #define IPI_MB_CHNL_RX	1 /* IPI mailbox RX channel */
57 
58 /* IPI Message Buffer Information */
59 #define RESP_OFFSET	0x20U
60 #define DEST_OFFSET	0x40U
61 #define IPI_BUF_SIZE	0x20U
62 #define DST_BIT_POS	9U
63 #define SRC_BITMASK	GENMASK(11, 8)
64 
65 /* Macro to represent SGI type for IPI IRQs */
66 #define IPI_IRQ_TYPE_SGI	2
67 
68 /*
69  * Module parameters
70  */
71 static int tx_poll_period = 5;
72 module_param_named(tx_poll_period, tx_poll_period, int, 0644);
73 MODULE_PARM_DESC(tx_poll_period, "Poll period waiting for ack after send.");
74 
75 /**
76  * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
77  * @is_opened: indicate if the IPI channel is opened
78  * @req_buf: local to remote request buffer start address
79  * @resp_buf: local to remote response buffer start address
80  * @req_buf_size: request buffer size
81  * @resp_buf_size: response buffer size
82  * @rx_buf: receive buffer to pass received message to client
83  * @chan_type: channel type
84  */
85 struct zynqmp_ipi_mchan {
86 	int is_opened;
87 	void __iomem *req_buf;
88 	void __iomem *resp_buf;
89 	void *rx_buf;
90 	size_t req_buf_size;
91 	size_t resp_buf_size;
92 	unsigned int chan_type;
93 };
94 
95 struct zynqmp_ipi_mbox;
96 
97 typedef int (*setup_ipi_fn)(struct zynqmp_ipi_mbox *ipi_mbox, struct device_node *node);
98 
99 /**
100  * struct zynqmp_ipi_mbox - Description of a ZynqMP IPI mailbox
101  *                          platform data.
102  * @pdata:		  pointer to the IPI private data
103  * @dev:                  device pointer corresponding to the Xilinx ZynqMP
104  *                        IPI mailbox
105  * @remote_id:            remote IPI agent ID
106  * @mbox:                 mailbox Controller
107  * @mchans:               array for channels, tx channel and rx channel.
108  * @setup_ipi_fn:         Function Pointer to set up IPI Channels
109  */
110 struct zynqmp_ipi_mbox {
111 	struct zynqmp_ipi_pdata *pdata;
112 	struct device dev;
113 	u32 remote_id;
114 	struct mbox_controller mbox;
115 	struct zynqmp_ipi_mchan mchans[2];
116 	setup_ipi_fn setup_ipi_fn;
117 };
118 
119 /**
120  * struct zynqmp_ipi_pdata - Description of z ZynqMP IPI agent platform data.
121  *
122  * @dev:                  device pointer corresponding to the Xilinx ZynqMP
123  *                        IPI agent
124  * @irq:                  IPI agent interrupt ID
125  * @irq_type:             IPI SGI or SPI IRQ type
126  * @method:               IPI SMC or HVC is going to be used
127  * @local_id:             local IPI agent ID
128  * @virq_sgi:             IRQ number mapped to SGI
129  * @num_mboxes:           number of mailboxes of this IPI agent
130  * @ipi_mboxes:           IPI mailboxes of this IPI agent
131  */
132 struct zynqmp_ipi_pdata {
133 	struct device *dev;
134 	int irq;
135 	unsigned int irq_type;
136 	unsigned int method;
137 	u32 local_id;
138 	int virq_sgi;
139 	int num_mboxes;
140 	struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
141 };
142 
143 static DEFINE_PER_CPU(struct zynqmp_ipi_pdata *, per_cpu_pdata);
144 
145 static struct device_driver zynqmp_ipi_mbox_driver = {
146 	.owner = THIS_MODULE,
147 	.name = "zynqmp-ipi-mbox",
148 };
149 
150 static void zynqmp_ipi_fw_call(struct zynqmp_ipi_mbox *ipi_mbox,
151 			       unsigned long a0, unsigned long a3,
152 			       struct arm_smccc_res *res)
153 {
154 	struct zynqmp_ipi_pdata *pdata = ipi_mbox->pdata;
155 	unsigned long a1, a2;
156 
157 	a1 = pdata->local_id;
158 	a2 = ipi_mbox->remote_id;
159 	if (pdata->method == USE_SMC)
160 		arm_smccc_smc(a0, a1, a2, a3, 0, 0, 0, 0, res);
161 	else
162 		arm_smccc_hvc(a0, a1, a2, a3, 0, 0, 0, 0, res);
163 }
164 
165 /**
166  * zynqmp_ipi_interrupt - Interrupt handler for IPI notification
167  *
168  * @irq:  Interrupt number
169  * @data: ZynqMP IPI mailbox platform data.
170  *
171  * Return: -EINVAL if there is no instance
172  * IRQ_NONE if the interrupt is not ours.
173  * IRQ_HANDLED if the rx interrupt was successfully handled.
174  */
175 static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data)
176 {
177 	struct zynqmp_ipi_pdata *pdata = data;
178 	struct mbox_chan *chan;
179 	struct zynqmp_ipi_mbox *ipi_mbox;
180 	struct zynqmp_ipi_mchan *mchan;
181 	struct zynqmp_ipi_message *msg;
182 	u64 arg0, arg3;
183 	struct arm_smccc_res res;
184 	int ret, i, status = IRQ_NONE;
185 
186 	(void)irq;
187 	arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
188 	arg3 = IPI_SMC_ENQUIRY_DIRQ_MASK;
189 	for (i = 0; i < pdata->num_mboxes; i++) {
190 		ipi_mbox = &pdata->ipi_mboxes[i];
191 		mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
192 		chan = &ipi_mbox->mbox.chans[IPI_MB_CHNL_RX];
193 		zynqmp_ipi_fw_call(ipi_mbox, arg0, arg3, &res);
194 		ret = (int)(res.a0 & 0xFFFFFFFF);
195 		if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
196 			if (mchan->is_opened) {
197 				msg = mchan->rx_buf;
198 				if (msg) {
199 					msg->len = mchan->req_buf_size;
200 					memcpy_fromio(msg->data, mchan->req_buf,
201 						      msg->len);
202 				}
203 				mbox_chan_received_data(chan, (void *)msg);
204 				status = IRQ_HANDLED;
205 			}
206 		}
207 	}
208 	return status;
209 }
210 
211 static irqreturn_t zynqmp_sgi_interrupt(int irq, void *data)
212 {
213 	struct zynqmp_ipi_pdata **pdata_ptr = data;
214 	struct zynqmp_ipi_pdata *pdata = *pdata_ptr;
215 
216 	return zynqmp_ipi_interrupt(irq, pdata);
217 }
218 
219 /**
220  * zynqmp_ipi_peek_data - Peek to see if there are any rx messages.
221  *
222  * @chan: Channel Pointer
223  *
224  * Return: 'true' if there is pending rx data, 'false' if there is none.
225  */
226 static bool zynqmp_ipi_peek_data(struct mbox_chan *chan)
227 {
228 	struct device *dev = chan->mbox->dev;
229 	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
230 	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
231 	int ret;
232 	u64 arg0;
233 	struct arm_smccc_res res;
234 
235 	if (WARN_ON(!ipi_mbox)) {
236 		dev_err(dev, "no platform drv data??\n");
237 		return false;
238 	}
239 
240 	arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
241 	zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
242 	ret = (int)(res.a0 & 0xFFFFFFFF);
243 
244 	if (mchan->chan_type == IPI_MB_CHNL_TX) {
245 		/* TX channel, check if the message has been acked
246 		 * by the remote, if yes, response is available.
247 		 */
248 		if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
249 			return false;
250 		else
251 			return true;
252 	} else if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
253 		/* RX channel, check if there is message arrived. */
254 		return true;
255 	}
256 	return false;
257 }
258 
259 /**
260  * zynqmp_ipi_last_tx_done - See if the last tx message is sent
261  *
262  * @chan: Channel pointer
263  *
264  * Return: 'true' is no pending tx data, 'false' if there are any.
265  */
266 static bool zynqmp_ipi_last_tx_done(struct mbox_chan *chan)
267 {
268 	struct device *dev = chan->mbox->dev;
269 	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
270 	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
271 	int ret;
272 	u64 arg0;
273 	struct arm_smccc_res res;
274 
275 	if (WARN_ON(!ipi_mbox)) {
276 		dev_err(dev, "no platform drv data??\n");
277 		return false;
278 	}
279 
280 	if (mchan->chan_type == IPI_MB_CHNL_TX) {
281 		/* We only need to check if the message been taken
282 		 * by the remote in the TX channel
283 		 */
284 		arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
285 		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
286 		/* Check the SMC call status, a0 of the result */
287 		ret = (int)(res.a0 & 0xFFFFFFFF);
288 		if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
289 			return false;
290 		return true;
291 	}
292 	/* Always true for the response message in RX channel */
293 	return true;
294 }
295 
296 /**
297  * zynqmp_ipi_send_data - Send data
298  *
299  * @chan: Channel Pointer
300  * @data: Message Pointer
301  *
302  * Return: 0 if all goes good, else appropriate error messages.
303  */
304 static int zynqmp_ipi_send_data(struct mbox_chan *chan, void *data)
305 {
306 	struct device *dev = chan->mbox->dev;
307 	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
308 	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
309 	struct zynqmp_ipi_message *msg = data;
310 	u64 arg0;
311 	struct arm_smccc_res res;
312 
313 	if (WARN_ON(!ipi_mbox)) {
314 		dev_err(dev, "no platform drv data??\n");
315 		return -EINVAL;
316 	}
317 
318 	if (mchan->chan_type == IPI_MB_CHNL_TX) {
319 		/* Send request message */
320 		if (msg && msg->len > mchan->req_buf_size && mchan->req_buf) {
321 			dev_err(dev, "channel %d message length %u > max %lu\n",
322 				mchan->chan_type, (unsigned int)msg->len,
323 				mchan->req_buf_size);
324 			return -EINVAL;
325 		}
326 		if (msg && msg->len && mchan->req_buf)
327 			memcpy_toio(mchan->req_buf, msg->data, msg->len);
328 		/* Kick IPI mailbox to send message */
329 		arg0 = SMC_IPI_MAILBOX_NOTIFY;
330 		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
331 	} else {
332 		/* Send response message */
333 		if (msg && msg->len > mchan->resp_buf_size && mchan->resp_buf) {
334 			dev_err(dev, "channel %d message length %u > max %lu\n",
335 				mchan->chan_type, (unsigned int)msg->len,
336 				mchan->resp_buf_size);
337 			return -EINVAL;
338 		}
339 		if (msg && msg->len && mchan->resp_buf)
340 			memcpy_toio(mchan->resp_buf, msg->data, msg->len);
341 		arg0 = SMC_IPI_MAILBOX_ACK;
342 		zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK,
343 				   &res);
344 	}
345 	return 0;
346 }
347 
348 /**
349  * zynqmp_ipi_startup - Startup the IPI channel
350  *
351  * @chan: Channel pointer
352  *
353  * Return: 0 if all goes good, else return corresponding error message
354  */
355 static int zynqmp_ipi_startup(struct mbox_chan *chan)
356 {
357 	struct device *dev = chan->mbox->dev;
358 	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
359 	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
360 	u64 arg0;
361 	struct arm_smccc_res res;
362 	int ret = 0;
363 	unsigned int nchan_type;
364 
365 	if (mchan->is_opened)
366 		return 0;
367 
368 	/* If no channel has been opened, open the IPI mailbox */
369 	nchan_type = (mchan->chan_type + 1) % 2;
370 	if (!ipi_mbox->mchans[nchan_type].is_opened) {
371 		arg0 = SMC_IPI_MAILBOX_OPEN;
372 		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
373 		/* Check the SMC call status, a0 of the result */
374 		ret = (int)(res.a0 & 0xFFFFFFFF);
375 		if (ret < 0) {
376 			dev_err(dev, "SMC to open the IPI channel failed.\n");
377 			return ret;
378 		}
379 		ret = 0;
380 	}
381 
382 	/* If it is RX channel, enable the IPI notification interrupt */
383 	if (mchan->chan_type == IPI_MB_CHNL_RX) {
384 		arg0 = SMC_IPI_MAILBOX_ENABLE_IRQ;
385 		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
386 	}
387 	mchan->is_opened = 1;
388 
389 	return ret;
390 }
391 
392 /**
393  * zynqmp_ipi_shutdown - Shutdown the IPI channel
394  *
395  * @chan: Channel pointer
396  */
397 static void zynqmp_ipi_shutdown(struct mbox_chan *chan)
398 {
399 	struct device *dev = chan->mbox->dev;
400 	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
401 	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
402 	u64 arg0;
403 	struct arm_smccc_res res;
404 	unsigned int chan_type;
405 
406 	if (!mchan->is_opened)
407 		return;
408 
409 	/* If it is RX channel, disable notification interrupt */
410 	chan_type = mchan->chan_type;
411 	if (chan_type == IPI_MB_CHNL_RX) {
412 		arg0 = SMC_IPI_MAILBOX_DISABLE_IRQ;
413 		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
414 	}
415 	/* Release IPI mailbox if no other channel is opened */
416 	chan_type = (chan_type + 1) % 2;
417 	if (!ipi_mbox->mchans[chan_type].is_opened) {
418 		arg0 = SMC_IPI_MAILBOX_RELEASE;
419 		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
420 	}
421 
422 	mchan->is_opened = 0;
423 }
424 
425 /* ZynqMP IPI mailbox operations */
426 static const struct mbox_chan_ops zynqmp_ipi_chan_ops = {
427 	.startup = zynqmp_ipi_startup,
428 	.shutdown = zynqmp_ipi_shutdown,
429 	.peek_data = zynqmp_ipi_peek_data,
430 	.last_tx_done = zynqmp_ipi_last_tx_done,
431 	.send_data = zynqmp_ipi_send_data,
432 };
433 
434 /**
435  * zynqmp_ipi_of_xlate - Translate of phandle to IPI mailbox channel
436  *
437  * @mbox: mailbox controller pointer
438  * @p:    phandle pointer
439  *
440  * Return: Mailbox channel, else return error pointer.
441  */
442 static struct mbox_chan *zynqmp_ipi_of_xlate(struct mbox_controller *mbox,
443 					     const struct of_phandle_args *p)
444 {
445 	struct mbox_chan *chan;
446 	struct device *dev = mbox->dev;
447 	unsigned int chan_type;
448 
449 	/* Only supports TX and RX channels */
450 	chan_type = p->args[0];
451 	if (chan_type != IPI_MB_CHNL_TX && chan_type != IPI_MB_CHNL_RX) {
452 		dev_err(dev, "req chnl failure: invalid chnl type %u.\n",
453 			chan_type);
454 		return ERR_PTR(-EINVAL);
455 	}
456 	chan = &mbox->chans[chan_type];
457 	return chan;
458 }
459 
460 /**
461  * zynqmp_ipi_mbox_get_buf_res - Get buffer resource from the IPI dev node
462  *
463  * @node: IPI mbox device child node
464  * @name: name of the IPI buffer
465  * @res: pointer to where the resource information will be stored.
466  *
467  * Return: 0 for success, negative value for failure
468  */
469 static int zynqmp_ipi_mbox_get_buf_res(struct device_node *node,
470 				       const char *name,
471 				       struct resource *res)
472 {
473 	int ret, index;
474 
475 	index = of_property_match_string(node, "reg-names", name);
476 	if (index >= 0) {
477 		ret = of_address_to_resource(node, index, res);
478 		if (ret < 0)
479 			return -EINVAL;
480 		return 0;
481 	}
482 	return -ENODEV;
483 }
484 
485 /**
486  * zynqmp_ipi_mbox_dev_release() - release the existence of a ipi mbox dev
487  *
488  * @dev: the ipi mailbox device
489  *
490  * This is to avoid the no device release() function kernel warning.
491  *
492  */
493 static void zynqmp_ipi_mbox_dev_release(struct device *dev)
494 {
495 	(void)dev;
496 }
497 
498 /**
499  * zynqmp_ipi_mbox_probe - probe IPI mailbox resource from device node
500  *
501  * @ipi_mbox: pointer to IPI mailbox private data structure
502  * @node: IPI mailbox device node
503  *
504  * Return: 0 for success, negative value for failure
505  */
506 static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox,
507 				 struct device_node *node)
508 {
509 	struct mbox_chan *chans;
510 	struct mbox_controller *mbox;
511 	struct device *dev, *mdev;
512 	int ret;
513 
514 	dev = ipi_mbox->pdata->dev;
515 	/* Initialize dev for IPI mailbox */
516 	ipi_mbox->dev.parent = dev;
517 	ipi_mbox->dev.release = NULL;
518 	ipi_mbox->dev.of_node = node;
519 	dev_set_name(&ipi_mbox->dev, "%s", of_node_full_name(node));
520 	dev_set_drvdata(&ipi_mbox->dev, ipi_mbox);
521 	ipi_mbox->dev.release = zynqmp_ipi_mbox_dev_release;
522 	ipi_mbox->dev.driver = &zynqmp_ipi_mbox_driver;
523 	ret = device_register(&ipi_mbox->dev);
524 	if (ret) {
525 		dev_err(dev, "Failed to register ipi mbox dev.\n");
526 		put_device(&ipi_mbox->dev);
527 		return ret;
528 	}
529 	mdev = &ipi_mbox->dev;
530 
531 	/* Get the IPI remote agent ID */
532 	ret = of_property_read_u32(node, "xlnx,ipi-id", &ipi_mbox->remote_id);
533 	if (ret < 0) {
534 		dev_err(dev, "No IPI remote ID is specified.\n");
535 		return ret;
536 	}
537 
538 	ret = ipi_mbox->setup_ipi_fn(ipi_mbox, node);
539 	if (ret) {
540 		dev_err(dev, "Failed to set up IPI Buffers.\n");
541 		return ret;
542 	}
543 
544 	mbox = &ipi_mbox->mbox;
545 	mbox->dev = mdev;
546 	mbox->ops = &zynqmp_ipi_chan_ops;
547 	mbox->num_chans = 2;
548 	mbox->txdone_irq = false;
549 	mbox->txdone_poll = true;
550 	mbox->txpoll_period = tx_poll_period;
551 	mbox->of_xlate = zynqmp_ipi_of_xlate;
552 	chans = devm_kzalloc(mdev, 2 * sizeof(*chans), GFP_KERNEL);
553 	if (!chans)
554 		return -ENOMEM;
555 	mbox->chans = chans;
556 	chans[IPI_MB_CHNL_TX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
557 	chans[IPI_MB_CHNL_RX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
558 	ipi_mbox->mchans[IPI_MB_CHNL_TX].chan_type = IPI_MB_CHNL_TX;
559 	ipi_mbox->mchans[IPI_MB_CHNL_RX].chan_type = IPI_MB_CHNL_RX;
560 	ret = devm_mbox_controller_register(mdev, mbox);
561 	if (ret)
562 		dev_err(mdev,
563 			"Failed to register mbox_controller(%d)\n", ret);
564 	else
565 		dev_info(mdev,
566 			 "Registered ZynqMP IPI mbox with TX/RX channels.\n");
567 	return ret;
568 }
569 
570 /**
571  * zynqmp_ipi_setup - set up IPI Buffers for classic flow
572  *
573  * @ipi_mbox: pointer to IPI mailbox private data structure
574  * @node: IPI mailbox device node
575  *
576  * This will be used to set up IPI Buffers for ZynqMP SOC if user
577  * wishes to use classic driver usage model on new SOC's with only
578  * buffered IPIs.
579  *
580  * Note that bufferless IPIs and mixed usage of buffered and bufferless
581  * IPIs are not supported with this flow.
582  *
583  * This will be invoked with compatible string "xlnx,zynqmp-ipi-mailbox".
584  *
585  * Return: 0 for success, negative value for failure
586  */
587 static int zynqmp_ipi_setup(struct zynqmp_ipi_mbox *ipi_mbox,
588 			    struct device_node *node)
589 {
590 	struct zynqmp_ipi_mchan *mchan;
591 	struct device *mdev;
592 	struct resource res;
593 	const char *name;
594 	int ret;
595 
596 	mdev = &ipi_mbox->dev;
597 
598 	mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
599 	name = "local_request_region";
600 	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
601 	if (!ret) {
602 		mchan->req_buf_size = resource_size(&res);
603 		mchan->req_buf = devm_ioremap(mdev, res.start,
604 					      mchan->req_buf_size);
605 		if (!mchan->req_buf) {
606 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
607 			return -ENOMEM;
608 		}
609 	} else if (ret != -ENODEV) {
610 		dev_err(mdev, "Unmatched resource %s, %d.\n", name, ret);
611 		return ret;
612 	}
613 
614 	name = "remote_response_region";
615 	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
616 	if (!ret) {
617 		mchan->resp_buf_size = resource_size(&res);
618 		mchan->resp_buf = devm_ioremap(mdev, res.start,
619 					       mchan->resp_buf_size);
620 		if (!mchan->resp_buf) {
621 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
622 			return -ENOMEM;
623 		}
624 	} else if (ret != -ENODEV) {
625 		dev_err(mdev, "Unmatched resource %s.\n", name);
626 		return ret;
627 	}
628 	mchan->rx_buf = devm_kzalloc(mdev,
629 				     mchan->resp_buf_size +
630 				     sizeof(struct zynqmp_ipi_message),
631 				     GFP_KERNEL);
632 	if (!mchan->rx_buf)
633 		return -ENOMEM;
634 
635 	mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
636 	name = "remote_request_region";
637 	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
638 	if (!ret) {
639 		mchan->req_buf_size = resource_size(&res);
640 		mchan->req_buf = devm_ioremap(mdev, res.start,
641 					      mchan->req_buf_size);
642 		if (!mchan->req_buf) {
643 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
644 			return -ENOMEM;
645 		}
646 	} else if (ret != -ENODEV) {
647 		dev_err(mdev, "Unmatched resource %s.\n", name);
648 		return ret;
649 	}
650 
651 	name = "local_response_region";
652 	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
653 	if (!ret) {
654 		mchan->resp_buf_size = resource_size(&res);
655 		mchan->resp_buf = devm_ioremap(mdev, res.start,
656 					       mchan->resp_buf_size);
657 		if (!mchan->resp_buf) {
658 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
659 			return -ENOMEM;
660 		}
661 	} else if (ret != -ENODEV) {
662 		dev_err(mdev, "Unmatched resource %s.\n", name);
663 		return ret;
664 	}
665 	mchan->rx_buf = devm_kzalloc(mdev,
666 				     mchan->resp_buf_size +
667 				     sizeof(struct zynqmp_ipi_message),
668 				     GFP_KERNEL);
669 	if (!mchan->rx_buf)
670 		return -ENOMEM;
671 
672 	return 0;
673 }
674 
675 /**
676  * versal_ipi_setup - Set up IPIs to support mixed usage of
677  *				 Buffered and Bufferless IPIs.
678  *
679  * @ipi_mbox: pointer to IPI mailbox private data structure
680  * @node: IPI mailbox device node
681  *
682  * Return: 0 for success, negative value for failure
683  */
684 static int versal_ipi_setup(struct zynqmp_ipi_mbox *ipi_mbox,
685 			    struct device_node *node)
686 {
687 	struct zynqmp_ipi_mchan *tx_mchan, *rx_mchan;
688 	struct resource host_res, remote_res;
689 	struct device_node *parent_node;
690 	int host_idx, remote_idx;
691 	struct device *mdev;
692 
693 	tx_mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
694 	rx_mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
695 	parent_node = of_get_parent(node);
696 	mdev = &ipi_mbox->dev;
697 
698 	host_idx = zynqmp_ipi_mbox_get_buf_res(parent_node, "msg", &host_res);
699 	remote_idx = zynqmp_ipi_mbox_get_buf_res(node, "msg", &remote_res);
700 
701 	/*
702 	 * Only set up buffers if both sides claim to have msg buffers.
703 	 * This is because each buffered IPI's corresponding msg buffers
704 	 * are reserved for use by other buffered IPI's.
705 	 */
706 	if (!host_idx && !remote_idx) {
707 		u32 host_src, host_dst, remote_src, remote_dst;
708 		u32 buff_sz;
709 
710 		buff_sz = resource_size(&host_res);
711 
712 		host_src = host_res.start & SRC_BITMASK;
713 		remote_src = remote_res.start & SRC_BITMASK;
714 
715 		host_dst = (host_src >> DST_BIT_POS) * DEST_OFFSET;
716 		remote_dst = (remote_src >> DST_BIT_POS) * DEST_OFFSET;
717 
718 		/* Validate that IPI IDs is within IPI Message buffer space. */
719 		if (host_dst >= buff_sz || remote_dst >= buff_sz) {
720 			dev_err(mdev,
721 				"Invalid IPI Message buffer values: %x %x\n",
722 				host_dst, remote_dst);
723 			return -EINVAL;
724 		}
725 
726 		tx_mchan->req_buf = devm_ioremap(mdev,
727 						 host_res.start | remote_dst,
728 						 IPI_BUF_SIZE);
729 		if (!tx_mchan->req_buf) {
730 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
731 			return -ENOMEM;
732 		}
733 
734 		tx_mchan->resp_buf = devm_ioremap(mdev,
735 						  (remote_res.start | host_dst) +
736 						  RESP_OFFSET, IPI_BUF_SIZE);
737 		if (!tx_mchan->resp_buf) {
738 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
739 			return -ENOMEM;
740 		}
741 
742 		rx_mchan->req_buf = devm_ioremap(mdev,
743 						 remote_res.start | host_dst,
744 						 IPI_BUF_SIZE);
745 		if (!rx_mchan->req_buf) {
746 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
747 			return -ENOMEM;
748 		}
749 
750 		rx_mchan->resp_buf = devm_ioremap(mdev,
751 						  (host_res.start | remote_dst) +
752 						  RESP_OFFSET, IPI_BUF_SIZE);
753 		if (!rx_mchan->resp_buf) {
754 			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
755 			return -ENOMEM;
756 		}
757 
758 		tx_mchan->resp_buf_size = IPI_BUF_SIZE;
759 		tx_mchan->req_buf_size = IPI_BUF_SIZE;
760 		tx_mchan->rx_buf = devm_kzalloc(mdev, IPI_BUF_SIZE +
761 						sizeof(struct zynqmp_ipi_message),
762 						GFP_KERNEL);
763 		if (!tx_mchan->rx_buf)
764 			return -ENOMEM;
765 
766 		rx_mchan->resp_buf_size = IPI_BUF_SIZE;
767 		rx_mchan->req_buf_size = IPI_BUF_SIZE;
768 		rx_mchan->rx_buf = devm_kzalloc(mdev, IPI_BUF_SIZE +
769 						sizeof(struct zynqmp_ipi_message),
770 						GFP_KERNEL);
771 		if (!rx_mchan->rx_buf)
772 			return -ENOMEM;
773 	}
774 
775 	return 0;
776 }
777 
778 static int xlnx_mbox_cpuhp_start(unsigned int cpu)
779 {
780 	struct zynqmp_ipi_pdata *pdata;
781 
782 	pdata = get_cpu_var(per_cpu_pdata);
783 	put_cpu_var(per_cpu_pdata);
784 	enable_percpu_irq(pdata->virq_sgi, IRQ_TYPE_NONE);
785 
786 	return 0;
787 }
788 
789 static int xlnx_mbox_cpuhp_down(unsigned int cpu)
790 {
791 	struct zynqmp_ipi_pdata *pdata;
792 
793 	pdata = get_cpu_var(per_cpu_pdata);
794 	put_cpu_var(per_cpu_pdata);
795 	disable_percpu_irq(pdata->virq_sgi);
796 
797 	return 0;
798 }
799 
800 static void xlnx_disable_percpu_irq(void *data)
801 {
802 	struct zynqmp_ipi_pdata *pdata;
803 
804 	pdata = *this_cpu_ptr(&per_cpu_pdata);
805 
806 	disable_percpu_irq(pdata->virq_sgi);
807 }
808 
809 static int xlnx_mbox_init_sgi(struct platform_device *pdev,
810 			      int sgi_num,
811 			      struct zynqmp_ipi_pdata *pdata)
812 {
813 	int ret = 0;
814 	int cpu;
815 
816 	/*
817 	 * IRQ related structures are used for the following:
818 	 * for each SGI interrupt ensure its mapped by GIC IRQ domain
819 	 * and that each corresponding linux IRQ for the HW IRQ has
820 	 * a handler for when receiving an interrupt from the remote
821 	 * processor.
822 	 */
823 	struct irq_domain *domain;
824 	struct irq_fwspec sgi_fwspec;
825 	struct device_node *interrupt_parent = NULL;
826 	struct device *dev = &pdev->dev;
827 
828 	/* Find GIC controller to map SGIs. */
829 	interrupt_parent = of_irq_find_parent(dev->of_node);
830 	if (!interrupt_parent) {
831 		dev_err(&pdev->dev, "Failed to find property for Interrupt parent\n");
832 		return -EINVAL;
833 	}
834 
835 	/* Each SGI needs to be associated with GIC's IRQ domain. */
836 	domain = irq_find_host(interrupt_parent);
837 	of_node_put(interrupt_parent);
838 
839 	/* Each mapping needs GIC domain when finding IRQ mapping. */
840 	sgi_fwspec.fwnode = domain->fwnode;
841 
842 	/*
843 	 * When irq domain looks at mapping each arg is as follows:
844 	 * 3 args for: interrupt type (SGI), interrupt # (set later), type
845 	 */
846 	sgi_fwspec.param_count = 1;
847 
848 	/* Set SGI's hwirq */
849 	sgi_fwspec.param[0] = sgi_num;
850 	pdata->virq_sgi = irq_create_fwspec_mapping(&sgi_fwspec);
851 
852 	for_each_possible_cpu(cpu)
853 		per_cpu(per_cpu_pdata, cpu) = pdata;
854 
855 	ret = request_percpu_irq(pdata->virq_sgi, zynqmp_sgi_interrupt, pdev->name,
856 				 &per_cpu_pdata);
857 	WARN_ON(ret);
858 	if (ret) {
859 		irq_dispose_mapping(pdata->virq_sgi);
860 		return ret;
861 	}
862 
863 	irq_set_status_flags(pdata->virq_sgi, IRQ_PER_CPU);
864 
865 	/* Setup function for the CPU hot-plug cases */
866 	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mailbox/sgi:starting",
867 			  xlnx_mbox_cpuhp_start, xlnx_mbox_cpuhp_down);
868 
869 	return ret;
870 }
871 
872 static void xlnx_mbox_cleanup_sgi(struct zynqmp_ipi_pdata *pdata)
873 {
874 	cpuhp_remove_state(CPUHP_AP_ONLINE_DYN);
875 
876 	on_each_cpu(xlnx_disable_percpu_irq, NULL, 1);
877 
878 	irq_clear_status_flags(pdata->virq_sgi, IRQ_PER_CPU);
879 	free_percpu_irq(pdata->virq_sgi, &per_cpu_pdata);
880 	irq_dispose_mapping(pdata->virq_sgi);
881 }
882 
883 /**
884  * zynqmp_ipi_free_mboxes - Free IPI mailboxes devices
885  *
886  * @pdata: IPI private data
887  */
888 static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
889 {
890 	struct zynqmp_ipi_mbox *ipi_mbox;
891 	int i;
892 
893 	if (pdata->irq_type == IPI_IRQ_TYPE_SGI)
894 		xlnx_mbox_cleanup_sgi(pdata);
895 
896 	i = pdata->num_mboxes - 1;
897 	for (; i >= 0; i--) {
898 		ipi_mbox = &pdata->ipi_mboxes[i];
899 		if (device_is_registered(&ipi_mbox->dev))
900 			device_unregister(&ipi_mbox->dev);
901 	}
902 }
903 
904 static int zynqmp_ipi_probe(struct platform_device *pdev)
905 {
906 	struct device *dev = &pdev->dev;
907 	struct device_node *nc, *np = pdev->dev.of_node;
908 	struct zynqmp_ipi_pdata *pdata;
909 	struct of_phandle_args out_irq;
910 	struct zynqmp_ipi_mbox *mbox;
911 	int num_mboxes, ret = -EINVAL;
912 	setup_ipi_fn ipi_fn;
913 
914 	num_mboxes = of_get_available_child_count(np);
915 	if (num_mboxes == 0) {
916 		dev_err(dev, "mailbox nodes not available\n");
917 		return -EINVAL;
918 	}
919 
920 	pdata = devm_kzalloc(dev, struct_size(pdata, ipi_mboxes, num_mboxes),
921 			     GFP_KERNEL);
922 	if (!pdata)
923 		return -ENOMEM;
924 	pdata->dev = dev;
925 
926 	/* Get the IPI local agents ID */
927 	ret = of_property_read_u32(np, "xlnx,ipi-id", &pdata->local_id);
928 	if (ret < 0) {
929 		dev_err(dev, "No IPI local ID is specified.\n");
930 		return ret;
931 	}
932 
933 	ipi_fn = (setup_ipi_fn)device_get_match_data(&pdev->dev);
934 	if (!ipi_fn) {
935 		dev_err(dev,
936 			"Mbox Compatible String is missing IPI Setup fn.\n");
937 		return -ENODEV;
938 	}
939 
940 	pdata->num_mboxes = num_mboxes;
941 
942 	mbox = pdata->ipi_mboxes;
943 	for_each_available_child_of_node(np, nc) {
944 		mbox->pdata = pdata;
945 		mbox->setup_ipi_fn = ipi_fn;
946 
947 		ret = zynqmp_ipi_mbox_probe(mbox, nc);
948 		if (ret) {
949 			of_node_put(nc);
950 			dev_err(dev, "failed to probe subdev.\n");
951 			ret = -EINVAL;
952 			goto free_mbox_dev;
953 		}
954 		mbox++;
955 	}
956 
957 	ret = of_irq_parse_one(dev_of_node(dev), 0, &out_irq);
958 	if (ret < 0) {
959 		dev_err(dev, "failed to parse interrupts\n");
960 		goto free_mbox_dev;
961 	}
962 
963 	/* Use interrupt type to distinguish SGI and SPI interrupts */
964 	pdata->irq_type = out_irq.args[0];
965 
966 	/*
967 	 * If Interrupt number is in SGI range, then request SGI else request
968 	 * IPI system IRQ.
969 	 */
970 	if (pdata->irq_type == IPI_IRQ_TYPE_SGI) {
971 		pdata->irq = out_irq.args[1];
972 		ret = xlnx_mbox_init_sgi(pdev, pdata->irq, pdata);
973 		if (ret)
974 			goto free_mbox_dev;
975 	} else {
976 		ret = platform_get_irq(pdev, 0);
977 		if (ret < 0)
978 			goto free_mbox_dev;
979 
980 		pdata->irq = ret;
981 		ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
982 				       IRQF_SHARED, dev_name(dev), pdata);
983 	}
984 
985 	if (ret) {
986 		dev_err(dev, "IRQ %d is not requested successfully.\n",
987 			pdata->irq);
988 		goto free_mbox_dev;
989 	}
990 
991 	platform_set_drvdata(pdev, pdata);
992 	return ret;
993 
994 free_mbox_dev:
995 	zynqmp_ipi_free_mboxes(pdata);
996 	return ret;
997 }
998 
999 static void zynqmp_ipi_remove(struct platform_device *pdev)
1000 {
1001 	struct zynqmp_ipi_pdata *pdata;
1002 
1003 	pdata = platform_get_drvdata(pdev);
1004 	zynqmp_ipi_free_mboxes(pdata);
1005 }
1006 
1007 static const struct of_device_id zynqmp_ipi_of_match[] = {
1008 	{ .compatible = "xlnx,zynqmp-ipi-mailbox",
1009 	  .data = &zynqmp_ipi_setup,
1010 	},
1011 	{ .compatible = "xlnx,versal-ipi-mailbox",
1012 	  .data = &versal_ipi_setup,
1013 	},
1014 	{},
1015 };
1016 MODULE_DEVICE_TABLE(of, zynqmp_ipi_of_match);
1017 
1018 static struct platform_driver zynqmp_ipi_driver = {
1019 	.probe = zynqmp_ipi_probe,
1020 	.remove = zynqmp_ipi_remove,
1021 	.driver = {
1022 		   .name = "zynqmp-ipi",
1023 		   .of_match_table = of_match_ptr(zynqmp_ipi_of_match),
1024 	},
1025 };
1026 
1027 static int __init zynqmp_ipi_init(void)
1028 {
1029 	return platform_driver_register(&zynqmp_ipi_driver);
1030 }
1031 subsys_initcall(zynqmp_ipi_init);
1032 
1033 static void __exit zynqmp_ipi_exit(void)
1034 {
1035 	platform_driver_unregister(&zynqmp_ipi_driver);
1036 }
1037 module_exit(zynqmp_ipi_exit);
1038 
1039 MODULE_LICENSE("GPL v2");
1040 MODULE_DESCRIPTION("Xilinx ZynqMP IPI Mailbox driver");
1041 MODULE_AUTHOR("Xilinx Inc.");
1042