711 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*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/seq_file.h>20#include <linux/soc/qcom/smem.h>21#include <linux/soc/qcom/smem_state.h>22#include <linux/spinlock.h>23 24/*25 * The Shared Memory Point to Point (SMP2P) protocol facilitates communication26 * of a single 32-bit value between two processors. Each value has a single27 * writer (the local side) and a single reader (the remote side). Values are28 * uniquely identified in the system by the directed edge (local processor ID29 * to remote processor ID) and a string identifier.30 *31 * Each processor is responsible for creating the outgoing SMEM items and each32 * item is writable by the local processor and readable by the remote33 * processor. By using two separate SMEM items that are single-reader and34 * single-writer, SMP2P does not require any remote locking mechanisms.35 *36 * The driver uses the Linux GPIO and interrupt framework to expose a virtual37 * GPIO for each outbound entry and a virtual interrupt controller for each38 * inbound entry.39 */40 41#define SMP2P_MAX_ENTRY 1642#define SMP2P_MAX_ENTRY_NAME 1643 44#define SMP2P_FEATURE_SSR_ACK 0x145#define SMP2P_FLAGS_RESTART_DONE_BIT 046#define SMP2P_FLAGS_RESTART_ACK_BIT 147 48#define SMP2P_MAGIC 0x504d532449#define SMP2P_ALL_FEATURES SMP2P_FEATURE_SSR_ACK50 51/**52 * struct smp2p_smem_item - in memory communication structure53 * @magic: magic number54 * @version: version - must be 155 * @features: features flag - currently unused56 * @local_pid: processor id of sending end57 * @remote_pid: processor id of receiving end58 * @total_entries: number of entries - always SMP2P_MAX_ENTRY59 * @valid_entries: number of allocated entries60 * @flags:61 * @entries: individual communication entries62 * @entries.name: name of the entry63 * @entries.value: content of the entry64 */65struct smp2p_smem_item {66 u32 magic;67 u8 version;68 unsigned features:24;69 u16 local_pid;70 u16 remote_pid;71 u16 total_entries;72 u16 valid_entries;73 u32 flags;74 75 struct {76 u8 name[SMP2P_MAX_ENTRY_NAME];77 u32 value;78 } entries[SMP2P_MAX_ENTRY];79} __packed;80 81/**82 * struct smp2p_entry - driver context matching one entry83 * @node: list entry to keep track of allocated entries84 * @smp2p: reference to the device driver context85 * @name: name of the entry, to match against smp2p_smem_item86 * @value: pointer to smp2p_smem_item entry value87 * @last_value: last handled value88 * @domain: irq_domain for inbound entries89 * @irq_enabled:bitmap to track enabled irq bits90 * @irq_rising: bitmap to mark irq bits for rising detection91 * @irq_falling:bitmap to mark irq bits for falling detection92 * @state: smem state handle93 * @lock: spinlock to protect read-modify-write of the value94 */95struct smp2p_entry {96 struct list_head node;97 struct qcom_smp2p *smp2p;98 99 const char *name;100 u32 *value;101 u32 last_value;102 103 struct irq_domain *domain;104 DECLARE_BITMAP(irq_enabled, 32);105 DECLARE_BITMAP(irq_rising, 32);106 DECLARE_BITMAP(irq_falling, 32);107 108 struct qcom_smem_state *state;109 110 spinlock_t lock;111};112 113#define SMP2P_INBOUND 0114#define SMP2P_OUTBOUND 1115 116/**117 * struct qcom_smp2p - device driver context118 * @dev: device driver handle119 * @in: pointer to the inbound smem item120 * @out: pointer to the outbound smem item121 * @smem_items: ids of the two smem items122 * @valid_entries: already scanned inbound entries123 * @ssr_ack_enabled: SMP2P_FEATURE_SSR_ACK feature is supported and was enabled124 * @ssr_ack: current cached state of the local ack bit125 * @negotiation_done: whether negotiating finished126 * @local_pid: processor id of the inbound edge127 * @remote_pid: processor id of the outbound edge128 * @ipc_regmap: regmap for the outbound ipc129 * @ipc_offset: offset within the regmap130 * @ipc_bit: bit in regmap@offset to kick to signal remote processor131 * @mbox_client: mailbox client handle132 * @mbox_chan: apcs ipc mailbox channel handle133 * @inbound: list of inbound entries134 * @outbound: list of outbound entries135 */136struct qcom_smp2p {137 struct device *dev;138 139 struct smp2p_smem_item *in;140 struct smp2p_smem_item *out;141 142 unsigned smem_items[SMP2P_OUTBOUND + 1];143 144 unsigned valid_entries;145 146 bool ssr_ack_enabled;147 bool ssr_ack;148 bool negotiation_done;149 150 unsigned local_pid;151 unsigned remote_pid;152 153 struct regmap *ipc_regmap;154 int ipc_offset;155 int ipc_bit;156 157 struct mbox_client mbox_client;158 struct mbox_chan *mbox_chan;159 160 struct list_head inbound;161 struct list_head outbound;162};163 164#define CREATE_TRACE_POINTS165#include "trace-smp2p.h"166 167static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)168{169 /* Make sure any updated data is written before the kick */170 wmb();171 172 if (smp2p->mbox_chan) {173 mbox_send_message(smp2p->mbox_chan, NULL);174 mbox_client_txdone(smp2p->mbox_chan, 0);175 } else {176 regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));177 }178}179 180static bool qcom_smp2p_check_ssr(struct qcom_smp2p *smp2p)181{182 struct smp2p_smem_item *in = smp2p->in;183 bool restart;184 185 if (!smp2p->ssr_ack_enabled)186 return false;187 188 restart = in->flags & BIT(SMP2P_FLAGS_RESTART_DONE_BIT);189 190 return restart != smp2p->ssr_ack;191}192 193static void qcom_smp2p_do_ssr_ack(struct qcom_smp2p *smp2p)194{195 struct smp2p_smem_item *out = smp2p->out;196 u32 val;197 198 trace_smp2p_ssr_ack(smp2p->dev);199 smp2p->ssr_ack = !smp2p->ssr_ack;200 201 val = out->flags & ~BIT(SMP2P_FLAGS_RESTART_ACK_BIT);202 if (smp2p->ssr_ack)203 val |= BIT(SMP2P_FLAGS_RESTART_ACK_BIT);204 out->flags = val;205 206 qcom_smp2p_kick(smp2p);207}208 209static void qcom_smp2p_negotiate(struct qcom_smp2p *smp2p)210{211 struct smp2p_smem_item *out = smp2p->out;212 struct smp2p_smem_item *in = smp2p->in;213 214 if (in->version == out->version) {215 out->features &= in->features;216 217 if (out->features & SMP2P_FEATURE_SSR_ACK)218 smp2p->ssr_ack_enabled = true;219 220 smp2p->negotiation_done = true;221 trace_smp2p_negotiate(smp2p->dev, out->features);222 }223}224 225static void qcom_smp2p_notify_in(struct qcom_smp2p *smp2p)226{227 struct smp2p_smem_item *in;228 struct smp2p_entry *entry;229 int irq_pin;230 u32 status;231 char buf[SMP2P_MAX_ENTRY_NAME];232 u32 val;233 int i;234 235 in = smp2p->in;236 237 /* Match newly created entries */238 for (i = smp2p->valid_entries; i < in->valid_entries; i++) {239 list_for_each_entry(entry, &smp2p->inbound, node) {240 memcpy(buf, in->entries[i].name, sizeof(buf));241 if (!strcmp(buf, entry->name)) {242 entry->value = &in->entries[i].value;243 break;244 }245 }246 }247 smp2p->valid_entries = i;248 249 /* Fire interrupts based on any value changes */250 list_for_each_entry(entry, &smp2p->inbound, node) {251 /* Ignore entries not yet allocated by the remote side */252 if (!entry->value)253 continue;254 255 val = readl(entry->value);256 257 status = val ^ entry->last_value;258 entry->last_value = val;259 260 trace_smp2p_notify_in(entry, status, val);261 262 /* No changes of this entry? */263 if (!status)264 continue;265 266 for_each_set_bit(i, entry->irq_enabled, 32) {267 if (!(status & BIT(i)))268 continue;269 270 if ((val & BIT(i) && test_bit(i, entry->irq_rising)) ||271 (!(val & BIT(i)) && test_bit(i, entry->irq_falling))) {272 irq_pin = irq_find_mapping(entry->domain, i);273 handle_nested_irq(irq_pin);274 }275 }276 }277}278 279/**280 * qcom_smp2p_intr() - interrupt handler for incoming notifications281 * @irq: unused282 * @data: smp2p driver context283 *284 * Handle notifications from the remote side to handle newly allocated entries285 * or any changes to the state bits of existing entries.286 *287 * Return: %IRQ_HANDLED288 */289static irqreturn_t qcom_smp2p_intr(int irq, void *data)290{291 struct smp2p_smem_item *in;292 struct qcom_smp2p *smp2p = data;293 unsigned int smem_id = smp2p->smem_items[SMP2P_INBOUND];294 unsigned int pid = smp2p->remote_pid;295 bool ack_restart;296 size_t size;297 298 in = smp2p->in;299 300 /* Acquire smem item, if not already found */301 if (!in) {302 in = qcom_smem_get(pid, smem_id, &size);303 if (IS_ERR(in)) {304 dev_err(smp2p->dev,305 "Unable to acquire remote smp2p item\n");306 goto out;307 }308 309 smp2p->in = in;310 }311 312 if (!smp2p->negotiation_done)313 qcom_smp2p_negotiate(smp2p);314 315 if (smp2p->negotiation_done) {316 ack_restart = qcom_smp2p_check_ssr(smp2p);317 qcom_smp2p_notify_in(smp2p);318 319 if (ack_restart)320 qcom_smp2p_do_ssr_ack(smp2p);321 }322 323out:324 return IRQ_HANDLED;325}326 327static void smp2p_mask_irq(struct irq_data *irqd)328{329 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);330 irq_hw_number_t irq = irqd_to_hwirq(irqd);331 332 clear_bit(irq, entry->irq_enabled);333}334 335static void smp2p_unmask_irq(struct irq_data *irqd)336{337 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);338 irq_hw_number_t irq = irqd_to_hwirq(irqd);339 340 set_bit(irq, entry->irq_enabled);341}342 343static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)344{345 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);346 irq_hw_number_t irq = irqd_to_hwirq(irqd);347 348 if (!(type & IRQ_TYPE_EDGE_BOTH))349 return -EINVAL;350 351 if (type & IRQ_TYPE_EDGE_RISING)352 set_bit(irq, entry->irq_rising);353 else354 clear_bit(irq, entry->irq_rising);355 356 if (type & IRQ_TYPE_EDGE_FALLING)357 set_bit(irq, entry->irq_falling);358 else359 clear_bit(irq, entry->irq_falling);360 361 return 0;362}363 364static void smp2p_irq_print_chip(struct irq_data *irqd, struct seq_file *p)365{366 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);367 368 seq_printf(p, " %8s", dev_name(entry->smp2p->dev));369}370 371static struct irq_chip smp2p_irq_chip = {372 .name = "smp2p",373 .irq_mask = smp2p_mask_irq,374 .irq_unmask = smp2p_unmask_irq,375 .irq_set_type = smp2p_set_irq_type,376 .irq_print_chip = smp2p_irq_print_chip,377};378 379static int smp2p_irq_map(struct irq_domain *d,380 unsigned int irq,381 irq_hw_number_t hw)382{383 struct smp2p_entry *entry = d->host_data;384 385 irq_set_chip_and_handler(irq, &smp2p_irq_chip, handle_level_irq);386 irq_set_chip_data(irq, entry);387 irq_set_nested_thread(irq, 1);388 irq_set_noprobe(irq);389 390 return 0;391}392 393static const struct irq_domain_ops smp2p_irq_ops = {394 .map = smp2p_irq_map,395 .xlate = irq_domain_xlate_twocell,396};397 398static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,399 struct smp2p_entry *entry,400 struct device_node *node)401{402 entry->domain = irq_domain_add_linear(node, 32, &smp2p_irq_ops, entry);403 if (!entry->domain) {404 dev_err(smp2p->dev, "failed to add irq_domain\n");405 return -ENOMEM;406 }407 408 return 0;409}410 411static int smp2p_update_bits(void *data, u32 mask, u32 value)412{413 struct smp2p_entry *entry = data;414 unsigned long flags;415 u32 orig;416 u32 val;417 418 spin_lock_irqsave(&entry->lock, flags);419 val = orig = readl(entry->value);420 val &= ~mask;421 val |= value;422 writel(val, entry->value);423 spin_unlock_irqrestore(&entry->lock, flags);424 425 trace_smp2p_update_bits(entry, orig, val);426 427 if (val != orig)428 qcom_smp2p_kick(entry->smp2p);429 430 return 0;431}432 433static const struct qcom_smem_state_ops smp2p_state_ops = {434 .update_bits = smp2p_update_bits,435};436 437static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,438 struct smp2p_entry *entry,439 struct device_node *node)440{441 struct smp2p_smem_item *out = smp2p->out;442 char buf[SMP2P_MAX_ENTRY_NAME] = {};443 444 /* Allocate an entry from the smem item */445 strscpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);446 memcpy(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);447 448 /* Make the logical entry reference the physical value */449 entry->value = &out->entries[out->valid_entries].value;450 451 out->valid_entries++;452 453 entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);454 if (IS_ERR(entry->state)) {455 dev_err(smp2p->dev, "failed to register qcom_smem_state\n");456 return PTR_ERR(entry->state);457 }458 459 return 0;460}461 462static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)463{464 struct smp2p_smem_item *out;465 unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];466 unsigned pid = smp2p->remote_pid;467 int ret;468 469 ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));470 if (ret < 0 && ret != -EEXIST) {471 if (ret != -EPROBE_DEFER)472 dev_err(smp2p->dev,473 "unable to allocate local smp2p item\n");474 return ret;475 }476 477 out = qcom_smem_get(pid, smem_id, NULL);478 if (IS_ERR(out)) {479 dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");480 return PTR_ERR(out);481 }482 483 memset(out, 0, sizeof(*out));484 out->magic = SMP2P_MAGIC;485 out->local_pid = smp2p->local_pid;486 out->remote_pid = smp2p->remote_pid;487 out->total_entries = SMP2P_MAX_ENTRY;488 out->valid_entries = 0;489 out->features = SMP2P_ALL_FEATURES;490 491 /*492 * Make sure the rest of the header is written before we validate the493 * item by writing a valid version number.494 */495 wmb();496 out->version = 1;497 498 qcom_smp2p_kick(smp2p);499 500 smp2p->out = out;501 502 return 0;503}504 505static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)506{507 struct device_node *syscon;508 struct device *dev = smp2p->dev;509 const char *key;510 int ret;511 512 syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0);513 if (!syscon) {514 dev_err(dev, "no qcom,ipc node\n");515 return -ENODEV;516 }517 518 smp2p->ipc_regmap = syscon_node_to_regmap(syscon);519 of_node_put(syscon);520 if (IS_ERR(smp2p->ipc_regmap))521 return PTR_ERR(smp2p->ipc_regmap);522 523 key = "qcom,ipc";524 ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset);525 if (ret < 0) {526 dev_err(dev, "no offset in %s\n", key);527 return -EINVAL;528 }529 530 ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit);531 if (ret < 0) {532 dev_err(dev, "no bit in %s\n", key);533 return -EINVAL;534 }535 536 return 0;537}538 539static int qcom_smp2p_probe(struct platform_device *pdev)540{541 struct smp2p_entry *entry;542 struct qcom_smp2p *smp2p;543 const char *key;544 int irq;545 int ret;546 547 smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL);548 if (!smp2p)549 return -ENOMEM;550 551 smp2p->dev = &pdev->dev;552 INIT_LIST_HEAD(&smp2p->inbound);553 INIT_LIST_HEAD(&smp2p->outbound);554 555 platform_set_drvdata(pdev, smp2p);556 557 key = "qcom,smem";558 ret = of_property_read_u32_array(pdev->dev.of_node, key,559 smp2p->smem_items, 2);560 if (ret)561 return ret;562 563 key = "qcom,local-pid";564 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);565 if (ret)566 goto report_read_failure;567 568 key = "qcom,remote-pid";569 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);570 if (ret)571 goto report_read_failure;572 573 irq = platform_get_irq(pdev, 0);574 if (irq < 0)575 return irq;576 577 smp2p->mbox_client.dev = &pdev->dev;578 smp2p->mbox_client.knows_txdone = true;579 smp2p->mbox_chan = mbox_request_channel(&smp2p->mbox_client, 0);580 if (IS_ERR(smp2p->mbox_chan)) {581 if (PTR_ERR(smp2p->mbox_chan) != -ENODEV)582 return PTR_ERR(smp2p->mbox_chan);583 584 smp2p->mbox_chan = NULL;585 586 ret = smp2p_parse_ipc(smp2p);587 if (ret)588 return ret;589 }590 591 ret = qcom_smp2p_alloc_outbound_item(smp2p);592 if (ret < 0)593 goto release_mbox;594 595 for_each_available_child_of_node_scoped(pdev->dev.of_node, node) {596 entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);597 if (!entry) {598 ret = -ENOMEM;599 goto unwind_interfaces;600 }601 602 entry->smp2p = smp2p;603 spin_lock_init(&entry->lock);604 605 ret = of_property_read_string(node, "qcom,entry-name", &entry->name);606 if (ret < 0)607 goto unwind_interfaces;608 609 if (of_property_read_bool(node, "interrupt-controller")) {610 ret = qcom_smp2p_inbound_entry(smp2p, entry, node);611 if (ret < 0)612 goto unwind_interfaces;613 614 list_add(&entry->node, &smp2p->inbound);615 } else {616 ret = qcom_smp2p_outbound_entry(smp2p, entry, node);617 if (ret < 0)618 goto unwind_interfaces;619 620 list_add(&entry->node, &smp2p->outbound);621 }622 }623 624 /* Kick the outgoing edge after allocating entries */625 qcom_smp2p_kick(smp2p);626 627 ret = devm_request_threaded_irq(&pdev->dev, irq,628 NULL, qcom_smp2p_intr,629 IRQF_ONESHOT,630 NULL, (void *)smp2p);631 if (ret) {632 dev_err(&pdev->dev, "failed to request interrupt\n");633 goto unwind_interfaces;634 }635 636 /*637 * Treat smp2p interrupt as wakeup source, but keep it disabled638 * by default. User space can decide enabling it depending on its639 * use cases. For example if remoteproc crashes and device wants640 * to handle it immediatedly (e.g. to not miss phone calls) it can641 * enable wakeup source from user space, while other devices which642 * do not have proper autosleep feature may want to handle it with643 * other wakeup events (e.g. Power button) instead waking up immediately.644 */645 device_set_wakeup_capable(&pdev->dev, true);646 647 ret = dev_pm_set_wake_irq(&pdev->dev, irq);648 if (ret)649 goto set_wake_irq_fail;650 651 return 0;652 653set_wake_irq_fail:654 dev_pm_clear_wake_irq(&pdev->dev);655 656unwind_interfaces:657 list_for_each_entry(entry, &smp2p->inbound, node)658 irq_domain_remove(entry->domain);659 660 list_for_each_entry(entry, &smp2p->outbound, node)661 qcom_smem_state_unregister(entry->state);662 663 smp2p->out->valid_entries = 0;664 665release_mbox:666 mbox_free_channel(smp2p->mbox_chan);667 668 return ret;669 670report_read_failure:671 dev_err(&pdev->dev, "failed to read %s\n", key);672 return -EINVAL;673}674 675static void qcom_smp2p_remove(struct platform_device *pdev)676{677 struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);678 struct smp2p_entry *entry;679 680 dev_pm_clear_wake_irq(&pdev->dev);681 682 list_for_each_entry(entry, &smp2p->inbound, node)683 irq_domain_remove(entry->domain);684 685 list_for_each_entry(entry, &smp2p->outbound, node)686 qcom_smem_state_unregister(entry->state);687 688 mbox_free_channel(smp2p->mbox_chan);689 690 smp2p->out->valid_entries = 0;691}692 693static const struct of_device_id qcom_smp2p_of_match[] = {694 { .compatible = "qcom,smp2p" },695 {}696};697MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match);698 699static struct platform_driver qcom_smp2p_driver = {700 .probe = qcom_smp2p_probe,701 .remove_new = qcom_smp2p_remove,702 .driver = {703 .name = "qcom_smp2p",704 .of_match_table = qcom_smp2p_of_match,705 },706};707module_platform_driver(qcom_smp2p_driver);708 709MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver");710MODULE_LICENSE("GPL v2");711