// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2015, Sony Mobile Communications Inc. * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved. */ #include #include #include #include #include #include #include #include #include /* * This driver implements the Qualcomm Shared Memory State Machine, a mechanism * for communicating single bit state information to remote processors. * * The implementation is based on two sections of shared memory; the first * holding the state bits and the second holding a matrix of subscription bits. * * The state bits are structured in entries of 32 bits, each belonging to one * system in the SoC. The entry belonging to the local system is considered * read-write, while the rest should be considered read-only. * * The subscription matrix consists of N bitmaps per entry, denoting interest * in updates of the entry for each of the N hosts. Upon updating a state bit * each host's subscription bitmap should be queried and the remote system * should be interrupted if they request so. * * The subscription matrix is laid out in entry-major order: * entry0: [host0 ... hostN] * . * . * entryM: [host0 ... hostN] * * A third, optional, shared memory region might contain information regarding * the number of entries in the state bitmap as well as number of columns in * the subscription matrix. */ /* * Shared memory identifiers, used to acquire handles to respective memory * region. */ #define SMEM_SMSM_SHARED_STATE 85 #define SMEM_SMSM_CPU_INTR_MASK 333 #define SMEM_SMSM_SIZE_INFO 419 /* * Default sizes, in case SMEM_SMSM_SIZE_INFO is not found. */ #define SMSM_DEFAULT_NUM_ENTRIES 8 #define SMSM_DEFAULT_NUM_HOSTS 3 struct smsm_entry; struct smsm_host; /** * struct qcom_smsm - smsm driver context * @dev: smsm device pointer * @local_host: column in the subscription matrix representing this system * @num_hosts: number of columns in the subscription matrix * @num_entries: number of entries in the state map and rows in the subscription * matrix * @local_state: pointer to the local processor's state bits * @subscription: pointer to local processor's row in subscription matrix * @state: smem state handle * @lock: spinlock for read-modify-write of the outgoing state * @entries: context for each of the entries * @hosts: context for each of the hosts */ struct qcom_smsm { struct device *dev; u32 local_host; u32 num_hosts; u32 num_entries; u32 *local_state; u32 *subscription; struct qcom_smem_state *state; spinlock_t lock; struct smsm_entry *entries; struct smsm_host *hosts; }; /** * struct smsm_entry - per remote processor entry context * @smsm: back-reference to driver context * @domain: IRQ domain for this entry, if representing a remote system * @irq_enabled: bitmap of which state bits IRQs are enabled * @irq_rising: bitmap tracking if rising bits should be propagated * @irq_falling: bitmap tracking if falling bits should be propagated * @last_value: snapshot of state bits last time the interrupts where propagated * @remote_state: pointer to this entry's state bits * @subscription: pointer to a row in the subscription matrix representing this * entry */ struct smsm_entry { struct qcom_smsm *smsm; struct irq_domain *domain; DECLARE_BITMAP(irq_enabled, 32); DECLARE_BITMAP(irq_rising, 32); DECLARE_BITMAP(irq_falling, 32); u32 last_value; u32 *remote_state; u32 *subscription; }; /** * struct smsm_host - representation of a remote host * @ipc_regmap: regmap for outgoing interrupt * @ipc_offset: offset in @ipc_regmap for outgoing interrupt * @ipc_bit: bit in @ipc_regmap + @ipc_offset for outgoing interrupt */ struct smsm_host { struct regmap *ipc_regmap; int ipc_offset; int ipc_bit; }; /** * smsm_update_bits() - change bit in outgoing entry and inform subscribers * @data: smsm context pointer * @offset: bit in the entry * @value: new value * * Used to set and clear the bits in the outgoing/local entry and inform * subscribers about the change. */ static int smsm_update_bits(void *data, u32 mask, u32 value) { struct qcom_smsm *smsm = data; struct smsm_host *hostp; unsigned long flags; u32 changes; u32 host; u32 orig; u32 val; spin_lock_irqsave(&smsm->lock, flags); /* Update the entry */ val = orig = readl(smsm->local_state); val &= ~mask; val |= value; /* Don't signal if we didn't change the value */ changes = val ^ orig; if (!changes) { spin_unlock_irqrestore(&smsm->lock, flags); goto done; } /* Write out the new value */ writel(val, smsm->local_state); spin_unlock_irqrestore(&smsm->lock, flags); /* Make sure the value update is ordered before any kicks */ wmb(); /* Iterate over all hosts to check whom wants a kick */ for (host = 0; host < smsm->num_hosts; host++) { hostp = &smsm->hosts[host]; val = readl(smsm->subscription + host); if (val & changes && hostp->ipc_regmap) { regmap_write(hostp->ipc_regmap, hostp->ipc_offset, BIT(hostp->ipc_bit)); } } done: return 0; } static const struct qcom_smem_state_ops smsm_state_ops = { .update_bits = smsm_update_bits, }; /** * smsm_intr() - cascading IRQ handler for SMSM * @irq: unused * @data: entry related to this IRQ * * This function cascades an incoming interrupt from a remote system, based on * the state bits and configuration. */ static irqreturn_t smsm_intr(int irq, void *data) { struct smsm_entry *entry = data; unsigned i; int irq_pin; u32 changed; u32 val; val = readl(entry->remote_state); changed = val ^ entry->last_value; entry->last_value = val; for_each_set_bit(i, entry->irq_enabled, 32) { if (!(changed & BIT(i))) continue; if (val & BIT(i)) { if (test_bit(i, entry->irq_rising)) { irq_pin = irq_find_mapping(entry->domain, i); handle_nested_irq(irq_pin); } } else { if (test_bit(i, entry->irq_falling)) { irq_pin = irq_find_mapping(entry->domain, i); handle_nested_irq(irq_pin); } } } return IRQ_HANDLED; } /** * smsm_mask_irq() - un-subscribe from cascades of IRQs of a certain staus bit * @irqd: IRQ handle to be masked * * This un-subscribes the local CPU from interrupts upon changes to the defines * status bit. The bit is also cleared from cascading. */ static void smsm_mask_irq(struct irq_data *irqd) { struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd); irq_hw_number_t irq = irqd_to_hwirq(irqd); struct qcom_smsm *smsm = entry->smsm; u32 val; if (entry->subscription) { val = readl(entry->subscription + smsm->local_host); val &= ~BIT(irq); writel(val, entry->subscription + smsm->local_host); } clear_bit(irq, entry->irq_enabled); } /** * smsm_unmask_irq() - subscribe to cascades of IRQs of a certain status bit * @irqd: IRQ handle to be unmasked * * This subscribes the local CPU to interrupts upon changes to the defined * status bit. The bit is also marked for cascading. */ static void smsm_unmask_irq(struct irq_data *irqd) { struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd); irq_hw_number_t irq = irqd_to_hwirq(irqd); struct qcom_smsm *smsm = entry->smsm; u32 val; set_bit(irq, entry->irq_enabled); if (entry->subscription) { val = readl(entry->subscription + smsm->local_host); val |= BIT(irq); writel(val, entry->subscription + smsm->local_host); } } /** * smsm_set_irq_type() - updates the requested IRQ type for the cascading * @irqd: consumer interrupt handle * @type: requested flags */ static int smsm_set_irq_type(struct irq_data *irqd, unsigned int type) { struct smsm_entry *entry = irq_data_get_irq_chip_data(irqd); irq_hw_number_t irq = irqd_to_hwirq(irqd); if (!(type & IRQ_TYPE_EDGE_BOTH)) return -EINVAL; if (type & IRQ_TYPE_EDGE_RISING) set_bit(irq, entry->irq_rising); else clear_bit(irq, entry->irq_rising); if (type & IRQ_TYPE_EDGE_FALLING) set_bit(irq, entry->irq_falling); else clear_bit(irq, entry->irq_falling); return 0; } static struct irq_chip smsm_irq_chip = { .name = "smsm", .irq_mask = smsm_mask_irq, .irq_unmask = smsm_unmask_irq, .irq_set_type = smsm_set_irq_type, }; /** * smsm_irq_map() - sets up a mapping for a cascaded IRQ * @d: IRQ domain representing an entry * @irq: IRQ to set up * @hw: unused */ static int smsm_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { struct smsm_entry *entry = d->host_data; irq_set_chip_and_handler(irq, &smsm_irq_chip, handle_level_irq); irq_set_chip_data(irq, entry); irq_set_nested_thread(irq, 1); return 0; } static const struct irq_domain_ops smsm_irq_ops = { .map = smsm_irq_map, .xlate = irq_domain_xlate_twocell, }; /** * smsm_parse_ipc() - parses a qcom,ipc-%d device tree property * @smsm: smsm driver context * @host_id: index of the remote host to be resolved * * Parses device tree to acquire the information needed for sending the * outgoing interrupts to a remote host - identified by @host_id. */ static int smsm_parse_ipc(struct qcom_smsm *smsm, unsigned host_id) { struct device_node *syscon; struct device_node *node = smsm->dev->of_node; struct smsm_host *host = &smsm->hosts[host_id]; char key[16]; int ret; snprintf(key, sizeof(key), "qcom,ipc-%d", host_id); syscon = of_parse_phandle(node, key, 0); if (!syscon) return 0; host->ipc_regmap = syscon_node_to_regmap(syscon); if (IS_ERR(host->ipc_regmap)) return PTR_ERR(host->ipc_regmap); ret = of_property_read_u32_index(node, key, 1, &host->ipc_offset); if (ret < 0) { dev_err(smsm->dev, "no offset in %s\n", key); return -EINVAL; } ret = of_property_read_u32_index(node, key, 2, &host->ipc_bit); if (ret < 0) { dev_err(smsm->dev, "no bit in %s\n", key); return -EINVAL; } return 0; } /** * smsm_inbound_entry() - parse DT and set up an entry representing a remote system * @smsm: smsm driver context * @entry: entry context to be set up * @node: dt node containing the entry's properties */ static int smsm_inbound_entry(struct qcom_smsm *smsm, struct smsm_entry *entry, struct device_node *node) { int ret; int irq; irq = irq_of_parse_and_map(node, 0); if (!irq) { dev_err(smsm->dev, "failed to parse smsm interrupt\n"); return -EINVAL; } ret = devm_request_threaded_irq(smsm->dev, irq, NULL, smsm_intr, IRQF_ONESHOT, "smsm", (void *)entry); if (ret) { dev_err(smsm->dev, "failed to request interrupt\n"); return ret; } entry->domain = irq_domain_add_linear(node, 32, &smsm_irq_ops, entry); if (!entry->domain) { dev_err(smsm->dev, "failed to add irq_domain\n"); return -ENOMEM; } return 0; } /** * smsm_get_size_info() - parse the optional memory segment for sizes * @smsm: smsm driver context * * Attempt to acquire the number of hosts and entries from the optional shared * memory location. Not being able to find this segment should indicate that * we're on a older system where these values was hard coded to * SMSM_DEFAULT_NUM_ENTRIES and SMSM_DEFAULT_NUM_HOSTS. * * Returns 0 on success, negative errno on failure. */ static int smsm_get_size_info(struct qcom_smsm *smsm) { size_t size; struct { u32 num_hosts; u32 num_entries; u32 reserved0; u32 reserved1; } *info; info = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SIZE_INFO, &size); if (IS_ERR(info) && PTR_ERR(info) != -ENOENT) { if (PTR_ERR(info) != -EPROBE_DEFER) dev_err(smsm->dev, "unable to retrieve smsm size info\n"); return PTR_ERR(info); } else if (IS_ERR(info) || size != sizeof(*info)) { dev_warn(smsm->dev, "no smsm size info, using defaults\n"); smsm->num_entries = SMSM_DEFAULT_NUM_ENTRIES; smsm->num_hosts = SMSM_DEFAULT_NUM_HOSTS; return 0; } smsm->num_entries = info->num_entries; smsm->num_hosts = info->num_hosts; dev_dbg(smsm->dev, "found custom size of smsm: %d entries %d hosts\n", smsm->num_entries, smsm->num_hosts); return 0; } static int qcom_smsm_probe(struct platform_device *pdev) { struct device_node *local_node; struct device_node *node; struct smsm_entry *entry; struct qcom_smsm *smsm; u32 *intr_mask; size_t size; u32 *states; u32 id; int ret; smsm = devm_kzalloc(&pdev->dev, sizeof(*smsm), GFP_KERNEL); if (!smsm) return -ENOMEM; smsm->dev = &pdev->dev; spin_lock_init(&smsm->lock); ret = smsm_get_size_info(smsm); if (ret) return ret; smsm->entries = devm_kcalloc(&pdev->dev, smsm->num_entries, sizeof(struct smsm_entry), GFP_KERNEL); if (!smsm->entries) return -ENOMEM; smsm->hosts = devm_kcalloc(&pdev->dev, smsm->num_hosts, sizeof(struct smsm_host), GFP_KERNEL); if (!smsm->hosts) return -ENOMEM; for_each_child_of_node(pdev->dev.of_node, local_node) { if (of_find_property(local_node, "#qcom,smem-state-cells", NULL)) break; } if (!local_node) { dev_err(&pdev->dev, "no state entry\n"); return -EINVAL; } of_property_read_u32(pdev->dev.of_node, "qcom,local-host", &smsm->local_host); /* Parse the host properties */ for (id = 0; id < smsm->num_hosts; id++) { ret = smsm_parse_ipc(smsm, id); if (ret < 0) return ret; } /* Acquire the main SMSM state vector */ ret = qcom_smem_alloc(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SHARED_STATE, smsm->num_entries * sizeof(u32)); if (ret < 0 && ret != -EEXIST) { dev_err(&pdev->dev, "unable to allocate shared state entry\n"); return ret; } states = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_SHARED_STATE, NULL); if (IS_ERR(states)) { dev_err(&pdev->dev, "Unable to acquire shared state entry\n"); return PTR_ERR(states); } /* Acquire the list of interrupt mask vectors */ size = smsm->num_entries * smsm->num_hosts * sizeof(u32); ret = qcom_smem_alloc(QCOM_SMEM_HOST_ANY, SMEM_SMSM_CPU_INTR_MASK, size); if (ret < 0 && ret != -EEXIST) { dev_err(&pdev->dev, "unable to allocate smsm interrupt mask\n"); return ret; } intr_mask = qcom_smem_get(QCOM_SMEM_HOST_ANY, SMEM_SMSM_CPU_INTR_MASK, NULL); if (IS_ERR(intr_mask)) { dev_err(&pdev->dev, "unable to acquire shared memory interrupt mask\n"); return PTR_ERR(intr_mask); } /* Setup the reference to the local state bits */ smsm->local_state = states + smsm->local_host; smsm->subscription = intr_mask + smsm->local_host * smsm->num_hosts; /* Register the outgoing state */ smsm->state = qcom_smem_state_register(local_node, &smsm_state_ops, smsm); if (IS_ERR(smsm->state)) { dev_err(smsm->dev, "failed to register qcom_smem_state\n"); return PTR_ERR(smsm->state); } /* Register handlers for remote processor entries of interest. */ for_each_available_child_of_node(pdev->dev.of_node, node) { if (!of_property_read_bool(node, "interrupt-controller")) continue; ret = of_property_read_u32(node, "reg", &id); if (ret || id >= smsm->num_entries) { dev_err(&pdev->dev, "invalid reg of entry\n"); if (!ret) ret = -EINVAL; goto unwind_interfaces; } entry = &smsm->entries[id]; entry->smsm = smsm; entry->remote_state = states + id; /* Setup subscription pointers and unsubscribe to any kicks */ entry->subscription = intr_mask + id * smsm->num_hosts; writel(0, entry->subscription + smsm->local_host); ret = smsm_inbound_entry(smsm, entry, node); if (ret < 0) goto unwind_interfaces; } platform_set_drvdata(pdev, smsm); return 0; unwind_interfaces: for (id = 0; id < smsm->num_entries; id++) if (smsm->entries[id].domain) irq_domain_remove(smsm->entries[id].domain); qcom_smem_state_unregister(smsm->state); return ret; } static int qcom_smsm_remove(struct platform_device *pdev) { struct qcom_smsm *smsm = platform_get_drvdata(pdev); unsigned id; for (id = 0; id < smsm->num_entries; id++) if (smsm->entries[id].domain) irq_domain_remove(smsm->entries[id].domain); qcom_smem_state_unregister(smsm->state); return 0; } static const struct of_device_id qcom_smsm_of_match[] = { { .compatible = "qcom,smsm" }, {} }; MODULE_DEVICE_TABLE(of, qcom_smsm_of_match); static struct platform_driver qcom_smsm_driver = { .probe = qcom_smsm_probe, .remove = qcom_smsm_remove, .driver = { .name = "qcom-smsm", .of_match_table = qcom_smsm_of_match, }, }; module_platform_driver(qcom_smsm_driver); MODULE_DESCRIPTION("Qualcomm Shared Memory State Machine driver"); MODULE_LICENSE("GPL v2");