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