1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015, Sony Mobile Communications AB.
4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5 */
6
7#include <linux/interrupt.h>
8#include <linux/list.h>
9#include <linux/io.h>
10#include <linux/of.h>
11#include <linux/irq.h>
12#include <linux/irqdomain.h>
13#include <linux/mailbox_client.h>
14#include <linux/mfd/syscon.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/pm_wakeirq.h>
18#include <linux/regmap.h>
19#include <linux/soc/qcom/smem.h>
20#include <linux/soc/qcom/smem_state.h>
21#include <linux/spinlock.h>
22
23/*
24 * The Shared Memory Point to Point (SMP2P) protocol facilitates communication
25 * of a single 32-bit value between two processors. Each value has a single
26 * writer (the local side) and a single reader (the remote side). Values are
27 * uniquely identified in the system by the directed edge (local processor ID
28 * to remote processor ID) and a string identifier.
29 *
30 * Each processor is responsible for creating the outgoing SMEM items and each
31 * item is writable by the local processor and readable by the remote
32 * processor. By using two separate SMEM items that are single-reader and
33 * single-writer, SMP2P does not require any remote locking mechanisms.
34 *
35 * The driver uses the Linux GPIO and interrupt framework to expose a virtual
36 * GPIO for each outbound entry and a virtual interrupt controller for each
37 * inbound entry.
38 */
39
40#define SMP2P_MAX_ENTRY 16
41#define SMP2P_MAX_ENTRY_NAME 16
42
43#define SMP2P_FEATURE_SSR_ACK 0x1
44#define SMP2P_FLAGS_RESTART_DONE_BIT 0
45#define SMP2P_FLAGS_RESTART_ACK_BIT 1
46
47#define SMP2P_MAGIC 0x504d5324
48#define SMP2P_ALL_FEATURES SMP2P_FEATURE_SSR_ACK
49
50/**
51 * struct smp2p_smem_item - in memory communication structure
52 * @magic: magic number
53 * @version: version - must be 1
54 * @features: features flag - currently unused
55 * @local_pid: processor id of sending end
56 * @remote_pid: processor id of receiving end
57 * @total_entries: number of entries - always SMP2P_MAX_ENTRY
58 * @valid_entries: number of allocated entries
59 * @flags:
60 * @entries: individual communication entries
61 * @entries.name: name of the entry
62 * @entries.value: content of the entry
63 */
64struct smp2p_smem_item {
65 u32 magic;
66 u8 version;
67 unsigned features:24;
68 u16 local_pid;
69 u16 remote_pid;
70 u16 total_entries;
71 u16 valid_entries;
72 u32 flags;
73
74 struct {
75 u8 name[SMP2P_MAX_ENTRY_NAME];
76 u32 value;
77 } entries[SMP2P_MAX_ENTRY];
78} __packed;
79
80/**
81 * struct smp2p_entry - driver context matching one entry
82 * @node: list entry to keep track of allocated entries
83 * @smp2p: reference to the device driver context
84 * @name: name of the entry, to match against smp2p_smem_item
85 * @value: pointer to smp2p_smem_item entry value
86 * @last_value: last handled value
87 * @domain: irq_domain for inbound entries
88 * @irq_enabled:bitmap to track enabled irq bits
89 * @irq_rising: bitmap to mark irq bits for rising detection
90 * @irq_falling:bitmap to mark irq bits for falling detection
91 * @state: smem state handle
92 * @lock: spinlock to protect read-modify-write of the value
93 */
94struct smp2p_entry {
95 struct list_head node;
96 struct qcom_smp2p *smp2p;
97
98 const char *name;
99 u32 *value;
100 u32 last_value;
101
102 struct irq_domain *domain;
103 DECLARE_BITMAP(irq_enabled, 32);
104 DECLARE_BITMAP(irq_rising, 32);
105 DECLARE_BITMAP(irq_falling, 32);
106
107 struct qcom_smem_state *state;
108
109 spinlock_t lock;
110};
111
112#define SMP2P_INBOUND 0
113#define SMP2P_OUTBOUND 1
114
115/**
116 * struct qcom_smp2p - device driver context
117 * @dev: device driver handle
118 * @in: pointer to the inbound smem item
119 * @out: pointer to the outbound smem item
120 * @smem_items: ids of the two smem items
121 * @valid_entries: already scanned inbound entries
122 * @ssr_ack_enabled: SMP2P_FEATURE_SSR_ACK feature is supported and was enabled
123 * @ssr_ack: current cached state of the local ack bit
124 * @negotiation_done: whether negotiating finished
125 * @local_pid: processor id of the inbound edge
126 * @remote_pid: processor id of the outbound edge
127 * @ipc_regmap: regmap for the outbound ipc
128 * @ipc_offset: offset within the regmap
129 * @ipc_bit: bit in regmap@offset to kick to signal remote processor
130 * @mbox_client: mailbox client handle
131 * @mbox_chan: apcs ipc mailbox channel handle
132 * @inbound: list of inbound entries
133 * @outbound: list of outbound entries
134 */
135struct qcom_smp2p {
136 struct device *dev;
137
138 struct smp2p_smem_item *in;
139 struct smp2p_smem_item *out;
140
141 unsigned smem_items[SMP2P_OUTBOUND + 1];
142
143 unsigned valid_entries;
144
145 bool ssr_ack_enabled;
146 bool ssr_ack;
147 bool negotiation_done;
148
149 unsigned local_pid;
150 unsigned remote_pid;
151
152 struct regmap *ipc_regmap;
153 int ipc_offset;
154 int ipc_bit;
155
156 struct mbox_client mbox_client;
157 struct mbox_chan *mbox_chan;
158
159 struct list_head inbound;
160 struct list_head outbound;
161};
162
163static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
164{
165 /* Make sure any updated data is written before the kick */
166 wmb();
167
168 if (smp2p->mbox_chan) {
169 mbox_send_message(chan: smp2p->mbox_chan, NULL);
170 mbox_client_txdone(chan: smp2p->mbox_chan, r: 0);
171 } else {
172 regmap_write(map: smp2p->ipc_regmap, reg: smp2p->ipc_offset, BIT(smp2p->ipc_bit));
173 }
174}
175
176static bool qcom_smp2p_check_ssr(struct qcom_smp2p *smp2p)
177{
178 struct smp2p_smem_item *in = smp2p->in;
179 bool restart;
180
181 if (!smp2p->ssr_ack_enabled)
182 return false;
183
184 restart = in->flags & BIT(SMP2P_FLAGS_RESTART_DONE_BIT);
185
186 return restart != smp2p->ssr_ack;
187}
188
189static void qcom_smp2p_do_ssr_ack(struct qcom_smp2p *smp2p)
190{
191 struct smp2p_smem_item *out = smp2p->out;
192 u32 val;
193
194 smp2p->ssr_ack = !smp2p->ssr_ack;
195
196 val = out->flags & ~BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
197 if (smp2p->ssr_ack)
198 val |= BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
199 out->flags = val;
200
201 qcom_smp2p_kick(smp2p);
202}
203
204static void qcom_smp2p_negotiate(struct qcom_smp2p *smp2p)
205{
206 struct smp2p_smem_item *out = smp2p->out;
207 struct smp2p_smem_item *in = smp2p->in;
208
209 if (in->version == out->version) {
210 out->features &= in->features;
211
212 if (out->features & SMP2P_FEATURE_SSR_ACK)
213 smp2p->ssr_ack_enabled = true;
214
215 smp2p->negotiation_done = true;
216 }
217}
218
219static void qcom_smp2p_notify_in(struct qcom_smp2p *smp2p)
220{
221 struct smp2p_smem_item *in;
222 struct smp2p_entry *entry;
223 int irq_pin;
224 u32 status;
225 char buf[SMP2P_MAX_ENTRY_NAME];
226 u32 val;
227 int i;
228
229 in = smp2p->in;
230
231 /* Match newly created entries */
232 for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
233 list_for_each_entry(entry, &smp2p->inbound, node) {
234 memcpy(buf, in->entries[i].name, sizeof(buf));
235 if (!strcmp(buf, entry->name)) {
236 entry->value = &in->entries[i].value;
237 break;
238 }
239 }
240 }
241 smp2p->valid_entries = i;
242
243 /* Fire interrupts based on any value changes */
244 list_for_each_entry(entry, &smp2p->inbound, node) {
245 /* Ignore entries not yet allocated by the remote side */
246 if (!entry->value)
247 continue;
248
249 val = readl(addr: entry->value);
250
251 status = val ^ entry->last_value;
252 entry->last_value = val;
253
254 /* No changes of this entry? */
255 if (!status)
256 continue;
257
258 for_each_set_bit(i, entry->irq_enabled, 32) {
259 if (!(status & BIT(i)))
260 continue;
261
262 if ((val & BIT(i) && test_bit(i, entry->irq_rising)) ||
263 (!(val & BIT(i)) && test_bit(i, entry->irq_falling))) {
264 irq_pin = irq_find_mapping(domain: entry->domain, hwirq: i);
265 handle_nested_irq(irq: irq_pin);
266 }
267 }
268 }
269}
270
271/**
272 * qcom_smp2p_intr() - interrupt handler for incoming notifications
273 * @irq: unused
274 * @data: smp2p driver context
275 *
276 * Handle notifications from the remote side to handle newly allocated entries
277 * or any changes to the state bits of existing entries.
278 *
279 * Return: %IRQ_HANDLED
280 */
281static irqreturn_t qcom_smp2p_intr(int irq, void *data)
282{
283 struct smp2p_smem_item *in;
284 struct qcom_smp2p *smp2p = data;
285 unsigned int smem_id = smp2p->smem_items[SMP2P_INBOUND];
286 unsigned int pid = smp2p->remote_pid;
287 bool ack_restart;
288 size_t size;
289
290 in = smp2p->in;
291
292 /* Acquire smem item, if not already found */
293 if (!in) {
294 in = qcom_smem_get(host: pid, item: smem_id, size: &size);
295 if (IS_ERR(ptr: in)) {
296 dev_err(smp2p->dev,
297 "Unable to acquire remote smp2p item\n");
298 goto out;
299 }
300
301 smp2p->in = in;
302 }
303
304 if (!smp2p->negotiation_done)
305 qcom_smp2p_negotiate(smp2p);
306
307 if (smp2p->negotiation_done) {
308 ack_restart = qcom_smp2p_check_ssr(smp2p);
309 qcom_smp2p_notify_in(smp2p);
310
311 if (ack_restart)
312 qcom_smp2p_do_ssr_ack(smp2p);
313 }
314
315out:
316 return IRQ_HANDLED;
317}
318
319static void smp2p_mask_irq(struct irq_data *irqd)
320{
321 struct smp2p_entry *entry = irq_data_get_irq_chip_data(d: irqd);
322 irq_hw_number_t irq = irqd_to_hwirq(d: irqd);
323
324 clear_bit(nr: irq, addr: entry->irq_enabled);
325}
326
327static void smp2p_unmask_irq(struct irq_data *irqd)
328{
329 struct smp2p_entry *entry = irq_data_get_irq_chip_data(d: irqd);
330 irq_hw_number_t irq = irqd_to_hwirq(d: irqd);
331
332 set_bit(nr: irq, addr: entry->irq_enabled);
333}
334
335static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)
336{
337 struct smp2p_entry *entry = irq_data_get_irq_chip_data(d: irqd);
338 irq_hw_number_t irq = irqd_to_hwirq(d: irqd);
339
340 if (!(type & IRQ_TYPE_EDGE_BOTH))
341 return -EINVAL;
342
343 if (type & IRQ_TYPE_EDGE_RISING)
344 set_bit(nr: irq, addr: entry->irq_rising);
345 else
346 clear_bit(nr: irq, addr: entry->irq_rising);
347
348 if (type & IRQ_TYPE_EDGE_FALLING)
349 set_bit(nr: irq, addr: entry->irq_falling);
350 else
351 clear_bit(nr: irq, addr: entry->irq_falling);
352
353 return 0;
354}
355
356static struct irq_chip smp2p_irq_chip = {
357 .name = "smp2p",
358 .irq_mask = smp2p_mask_irq,
359 .irq_unmask = smp2p_unmask_irq,
360 .irq_set_type = smp2p_set_irq_type,
361};
362
363static int smp2p_irq_map(struct irq_domain *d,
364 unsigned int irq,
365 irq_hw_number_t hw)
366{
367 struct smp2p_entry *entry = d->host_data;
368
369 irq_set_chip_and_handler(irq, chip: &smp2p_irq_chip, handle: handle_level_irq);
370 irq_set_chip_data(irq, data: entry);
371 irq_set_nested_thread(irq, nest: 1);
372 irq_set_noprobe(irq);
373
374 return 0;
375}
376
377static const struct irq_domain_ops smp2p_irq_ops = {
378 .map = smp2p_irq_map,
379 .xlate = irq_domain_xlate_twocell,
380};
381
382static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
383 struct smp2p_entry *entry,
384 struct device_node *node)
385{
386 entry->domain = irq_domain_add_linear(of_node: node, size: 32, ops: &smp2p_irq_ops, host_data: entry);
387 if (!entry->domain) {
388 dev_err(smp2p->dev, "failed to add irq_domain\n");
389 return -ENOMEM;
390 }
391
392 return 0;
393}
394
395static int smp2p_update_bits(void *data, u32 mask, u32 value)
396{
397 struct smp2p_entry *entry = data;
398 unsigned long flags;
399 u32 orig;
400 u32 val;
401
402 spin_lock_irqsave(&entry->lock, flags);
403 val = orig = readl(addr: entry->value);
404 val &= ~mask;
405 val |= value;
406 writel(val, addr: entry->value);
407 spin_unlock_irqrestore(lock: &entry->lock, flags);
408
409 if (val != orig)
410 qcom_smp2p_kick(smp2p: entry->smp2p);
411
412 return 0;
413}
414
415static const struct qcom_smem_state_ops smp2p_state_ops = {
416 .update_bits = smp2p_update_bits,
417};
418
419static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
420 struct smp2p_entry *entry,
421 struct device_node *node)
422{
423 struct smp2p_smem_item *out = smp2p->out;
424 char buf[SMP2P_MAX_ENTRY_NAME] = {};
425
426 /* Allocate an entry from the smem item */
427 strscpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
428 memcpy(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
429
430 /* Make the logical entry reference the physical value */
431 entry->value = &out->entries[out->valid_entries].value;
432
433 out->valid_entries++;
434
435 entry->state = qcom_smem_state_register(of_node: node, ops: &smp2p_state_ops, data: entry);
436 if (IS_ERR(ptr: entry->state)) {
437 dev_err(smp2p->dev, "failed to register qcom_smem_state\n");
438 return PTR_ERR(ptr: entry->state);
439 }
440
441 return 0;
442}
443
444static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
445{
446 struct smp2p_smem_item *out;
447 unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
448 unsigned pid = smp2p->remote_pid;
449 int ret;
450
451 ret = qcom_smem_alloc(host: pid, item: smem_id, size: sizeof(*out));
452 if (ret < 0 && ret != -EEXIST) {
453 if (ret != -EPROBE_DEFER)
454 dev_err(smp2p->dev,
455 "unable to allocate local smp2p item\n");
456 return ret;
457 }
458
459 out = qcom_smem_get(host: pid, item: smem_id, NULL);
460 if (IS_ERR(ptr: out)) {
461 dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");
462 return PTR_ERR(ptr: out);
463 }
464
465 memset(out, 0, sizeof(*out));
466 out->magic = SMP2P_MAGIC;
467 out->local_pid = smp2p->local_pid;
468 out->remote_pid = smp2p->remote_pid;
469 out->total_entries = SMP2P_MAX_ENTRY;
470 out->valid_entries = 0;
471 out->features = SMP2P_ALL_FEATURES;
472
473 /*
474 * Make sure the rest of the header is written before we validate the
475 * item by writing a valid version number.
476 */
477 wmb();
478 out->version = 1;
479
480 qcom_smp2p_kick(smp2p);
481
482 smp2p->out = out;
483
484 return 0;
485}
486
487static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)
488{
489 struct device_node *syscon;
490 struct device *dev = smp2p->dev;
491 const char *key;
492 int ret;
493
494 syscon = of_parse_phandle(np: dev->of_node, phandle_name: "qcom,ipc", index: 0);
495 if (!syscon) {
496 dev_err(dev, "no qcom,ipc node\n");
497 return -ENODEV;
498 }
499
500 smp2p->ipc_regmap = syscon_node_to_regmap(np: syscon);
501 of_node_put(node: syscon);
502 if (IS_ERR(ptr: smp2p->ipc_regmap))
503 return PTR_ERR(ptr: smp2p->ipc_regmap);
504
505 key = "qcom,ipc";
506 ret = of_property_read_u32_index(np: dev->of_node, propname: key, index: 1, out_value: &smp2p->ipc_offset);
507 if (ret < 0) {
508 dev_err(dev, "no offset in %s\n", key);
509 return -EINVAL;
510 }
511
512 ret = of_property_read_u32_index(np: dev->of_node, propname: key, index: 2, out_value: &smp2p->ipc_bit);
513 if (ret < 0) {
514 dev_err(dev, "no bit in %s\n", key);
515 return -EINVAL;
516 }
517
518 return 0;
519}
520
521static int qcom_smp2p_probe(struct platform_device *pdev)
522{
523 struct smp2p_entry *entry;
524 struct device_node *node;
525 struct qcom_smp2p *smp2p;
526 const char *key;
527 int irq;
528 int ret;
529
530 smp2p = devm_kzalloc(dev: &pdev->dev, size: sizeof(*smp2p), GFP_KERNEL);
531 if (!smp2p)
532 return -ENOMEM;
533
534 smp2p->dev = &pdev->dev;
535 INIT_LIST_HEAD(list: &smp2p->inbound);
536 INIT_LIST_HEAD(list: &smp2p->outbound);
537
538 platform_set_drvdata(pdev, data: smp2p);
539
540 key = "qcom,smem";
541 ret = of_property_read_u32_array(np: pdev->dev.of_node, propname: key,
542 out_values: smp2p->smem_items, sz: 2);
543 if (ret)
544 return ret;
545
546 key = "qcom,local-pid";
547 ret = of_property_read_u32(np: pdev->dev.of_node, propname: key, out_value: &smp2p->local_pid);
548 if (ret)
549 goto report_read_failure;
550
551 key = "qcom,remote-pid";
552 ret = of_property_read_u32(np: pdev->dev.of_node, propname: key, out_value: &smp2p->remote_pid);
553 if (ret)
554 goto report_read_failure;
555
556 irq = platform_get_irq(pdev, 0);
557 if (irq < 0)
558 return irq;
559
560 smp2p->mbox_client.dev = &pdev->dev;
561 smp2p->mbox_client.knows_txdone = true;
562 smp2p->mbox_chan = mbox_request_channel(cl: &smp2p->mbox_client, index: 0);
563 if (IS_ERR(ptr: smp2p->mbox_chan)) {
564 if (PTR_ERR(ptr: smp2p->mbox_chan) != -ENODEV)
565 return PTR_ERR(ptr: smp2p->mbox_chan);
566
567 smp2p->mbox_chan = NULL;
568
569 ret = smp2p_parse_ipc(smp2p);
570 if (ret)
571 return ret;
572 }
573
574 ret = qcom_smp2p_alloc_outbound_item(smp2p);
575 if (ret < 0)
576 goto release_mbox;
577
578 for_each_available_child_of_node(pdev->dev.of_node, node) {
579 entry = devm_kzalloc(dev: &pdev->dev, size: sizeof(*entry), GFP_KERNEL);
580 if (!entry) {
581 ret = -ENOMEM;
582 of_node_put(node);
583 goto unwind_interfaces;
584 }
585
586 entry->smp2p = smp2p;
587 spin_lock_init(&entry->lock);
588
589 ret = of_property_read_string(np: node, propname: "qcom,entry-name", out_string: &entry->name);
590 if (ret < 0) {
591 of_node_put(node);
592 goto unwind_interfaces;
593 }
594
595 if (of_property_read_bool(np: node, propname: "interrupt-controller")) {
596 ret = qcom_smp2p_inbound_entry(smp2p, entry, node);
597 if (ret < 0) {
598 of_node_put(node);
599 goto unwind_interfaces;
600 }
601
602 list_add(new: &entry->node, head: &smp2p->inbound);
603 } else {
604 ret = qcom_smp2p_outbound_entry(smp2p, entry, node);
605 if (ret < 0) {
606 of_node_put(node);
607 goto unwind_interfaces;
608 }
609
610 list_add(new: &entry->node, head: &smp2p->outbound);
611 }
612 }
613
614 /* Kick the outgoing edge after allocating entries */
615 qcom_smp2p_kick(smp2p);
616
617 ret = devm_request_threaded_irq(dev: &pdev->dev, irq,
618 NULL, thread_fn: qcom_smp2p_intr,
619 IRQF_ONESHOT,
620 devname: "smp2p", dev_id: (void *)smp2p);
621 if (ret) {
622 dev_err(&pdev->dev, "failed to request interrupt\n");
623 goto unwind_interfaces;
624 }
625
626 /*
627 * Treat smp2p interrupt as wakeup source, but keep it disabled
628 * by default. User space can decide enabling it depending on its
629 * use cases. For example if remoteproc crashes and device wants
630 * to handle it immediatedly (e.g. to not miss phone calls) it can
631 * enable wakeup source from user space, while other devices which
632 * do not have proper autosleep feature may want to handle it with
633 * other wakeup events (e.g. Power button) instead waking up immediately.
634 */
635 device_set_wakeup_capable(dev: &pdev->dev, capable: true);
636
637 ret = dev_pm_set_wake_irq(dev: &pdev->dev, irq);
638 if (ret)
639 goto set_wake_irq_fail;
640
641 return 0;
642
643set_wake_irq_fail:
644 dev_pm_clear_wake_irq(dev: &pdev->dev);
645
646unwind_interfaces:
647 list_for_each_entry(entry, &smp2p->inbound, node)
648 irq_domain_remove(host: entry->domain);
649
650 list_for_each_entry(entry, &smp2p->outbound, node)
651 qcom_smem_state_unregister(state: entry->state);
652
653 smp2p->out->valid_entries = 0;
654
655release_mbox:
656 mbox_free_channel(chan: smp2p->mbox_chan);
657
658 return ret;
659
660report_read_failure:
661 dev_err(&pdev->dev, "failed to read %s\n", key);
662 return -EINVAL;
663}
664
665static void qcom_smp2p_remove(struct platform_device *pdev)
666{
667 struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);
668 struct smp2p_entry *entry;
669
670 dev_pm_clear_wake_irq(dev: &pdev->dev);
671
672 list_for_each_entry(entry, &smp2p->inbound, node)
673 irq_domain_remove(host: entry->domain);
674
675 list_for_each_entry(entry, &smp2p->outbound, node)
676 qcom_smem_state_unregister(state: entry->state);
677
678 mbox_free_channel(chan: smp2p->mbox_chan);
679
680 smp2p->out->valid_entries = 0;
681}
682
683static const struct of_device_id qcom_smp2p_of_match[] = {
684 { .compatible = "qcom,smp2p" },
685 {}
686};
687MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match);
688
689static struct platform_driver qcom_smp2p_driver = {
690 .probe = qcom_smp2p_probe,
691 .remove_new = qcom_smp2p_remove,
692 .driver = {
693 .name = "qcom_smp2p",
694 .of_match_table = qcom_smp2p_of_match,
695 },
696};
697module_platform_driver(qcom_smp2p_driver);
698
699MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver");
700MODULE_LICENSE("GPL v2");
701

source code of linux/drivers/soc/qcom/smp2p.c