// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. * Copyright (C) 2019-2020 Linaro Ltd. */ #include #include #include #include #include #include #include "ipa_smp2p.h" #include "ipa.h" #include "ipa_uc.h" #include "ipa_clock.h" /** * DOC: IPA SMP2P communication with the modem * * SMP2P is a primitive communication mechanism available between the AP and * the modem. The IPA driver uses this for two purposes: to enable the modem * to state that the GSI hardware is ready to use; and to communicate the * state of the IPA clock in the event of a crash. * * GSI needs to have early initialization completed before it can be used. * This initialization is done either by Trust Zone or by the modem. In the * latter case, the modem uses an SMP2P interrupt to tell the AP IPA driver * when the GSI is ready to use. * * The modem is also able to inquire about the current state of the IPA * clock by trigging another SMP2P interrupt to the AP. We communicate * whether the clock is enabled using two SMP2P state bits--one to * indicate the clock state (on or off), and a second to indicate the * clock state bit is valid. The modem will poll the valid bit until it * is set, and at that time records whether the AP has the IPA clock enabled. * * Finally, if the AP kernel panics, we update the SMP2P state bits even if * we never receive an interrupt from the modem requesting this. */ /** * struct ipa_smp2p - IPA SMP2P information * @ipa: IPA pointer * @valid_state: SMEM state indicating enabled state is valid * @enabled_state: SMEM state to indicate clock is enabled * @valid_bit: Valid bit in 32-bit SMEM state mask * @enabled_bit: Enabled bit in 32-bit SMEM state mask * @enabled_bit: Enabled bit in 32-bit SMEM state mask * @clock_query_irq: IPA interrupt triggered by modem for clock query * @setup_ready_irq: IPA interrupt triggered by modem to signal GSI ready * @clock_on: Whether IPA clock is on * @notified: Whether modem has been notified of clock state * @disabled: Whether setup ready interrupt handling is disabled * @mutex mutex: Motex protecting ready interrupt/shutdown interlock * @panic_notifier: Panic notifier structure */ struct ipa_smp2p { struct ipa *ipa; struct qcom_smem_state *valid_state; struct qcom_smem_state *enabled_state; u32 valid_bit; u32 enabled_bit; u32 clock_query_irq; u32 setup_ready_irq; bool clock_on; bool notified; bool disabled; struct mutex mutex; struct notifier_block panic_notifier; }; /** * ipa_smp2p_notify() - use SMP2P to tell modem about IPA clock state * @smp2p: SMP2P information * * This is called either when the modem has requested it (by triggering * the modem clock query IPA interrupt) or whenever the AP is shutting down * (via a panic notifier). It sets the two SMP2P state bits--one saying * whether the IPA clock is running, and the other indicating the first bit * is valid. */ static void ipa_smp2p_notify(struct ipa_smp2p *smp2p) { u32 value; u32 mask; if (smp2p->notified) return; smp2p->clock_on = ipa_clock_get_additional(smp2p->ipa); /* Signal whether the clock is enabled */ mask = BIT(smp2p->enabled_bit); value = smp2p->clock_on ? mask : 0; qcom_smem_state_update_bits(smp2p->enabled_state, mask, value); /* Now indicate that the enabled flag is valid */ mask = BIT(smp2p->valid_bit); value = mask; qcom_smem_state_update_bits(smp2p->valid_state, mask, value); smp2p->notified = true; } /* Threaded IRQ handler for modem "ipa-clock-query" SMP2P interrupt */ static irqreturn_t ipa_smp2p_modem_clk_query_isr(int irq, void *dev_id) { struct ipa_smp2p *smp2p = dev_id; ipa_smp2p_notify(smp2p); return IRQ_HANDLED; } static int ipa_smp2p_panic_notifier(struct notifier_block *nb, unsigned long action, void *data) { struct ipa_smp2p *smp2p; smp2p = container_of(nb, struct ipa_smp2p, panic_notifier); ipa_smp2p_notify(smp2p); if (smp2p->clock_on) ipa_uc_panic_notifier(smp2p->ipa); return NOTIFY_DONE; } static int ipa_smp2p_panic_notifier_register(struct ipa_smp2p *smp2p) { /* IPA panic handler needs to run before modem shuts down */ smp2p->panic_notifier.notifier_call = ipa_smp2p_panic_notifier; smp2p->panic_notifier.priority = INT_MAX; /* Do it early */ return atomic_notifier_chain_register(&panic_notifier_list, &smp2p->panic_notifier); } static void ipa_smp2p_panic_notifier_unregister(struct ipa_smp2p *smp2p) { atomic_notifier_chain_unregister(&panic_notifier_list, &smp2p->panic_notifier); } /* Threaded IRQ handler for modem "ipa-setup-ready" SMP2P interrupt */ static irqreturn_t ipa_smp2p_modem_setup_ready_isr(int irq, void *dev_id) { struct ipa_smp2p *smp2p = dev_id; mutex_lock(&smp2p->mutex); if (!smp2p->disabled) { int ret; ret = ipa_setup(smp2p->ipa); if (ret) dev_err(&smp2p->ipa->pdev->dev, "error %d from ipa_setup()\n", ret); smp2p->disabled = true; } mutex_unlock(&smp2p->mutex); return IRQ_HANDLED; } /* Initialize SMP2P interrupts */ static int ipa_smp2p_irq_init(struct ipa_smp2p *smp2p, const char *name, irq_handler_t handler) { struct device *dev = &smp2p->ipa->pdev->dev; unsigned int irq; int ret; ret = platform_get_irq_byname(smp2p->ipa->pdev, name); if (ret <= 0) { dev_err(dev, "DT error %d getting \"%s\" IRQ property\n", ret, name); return ret ? : -EINVAL; } irq = ret; ret = request_threaded_irq(irq, NULL, handler, 0, name, smp2p); if (ret) { dev_err(dev, "error %d requesting \"%s\" IRQ\n", ret, name); return ret; } return irq; } static void ipa_smp2p_irq_exit(struct ipa_smp2p *smp2p, u32 irq) { free_irq(irq, smp2p); } /* Drop the clock reference if it was taken in ipa_smp2p_notify() */ static void ipa_smp2p_clock_release(struct ipa *ipa) { if (!ipa->smp2p->clock_on) return; ipa_clock_put(ipa); ipa->smp2p->clock_on = false; } /* Initialize the IPA SMP2P subsystem */ int ipa_smp2p_init(struct ipa *ipa, bool modem_init) { struct qcom_smem_state *enabled_state; struct device *dev = &ipa->pdev->dev; struct qcom_smem_state *valid_state; struct ipa_smp2p *smp2p; u32 enabled_bit; u32 valid_bit; int ret; valid_state = qcom_smem_state_get(dev, "ipa-clock-enabled-valid", &valid_bit); if (IS_ERR(valid_state)) return PTR_ERR(valid_state); if (valid_bit >= 32) /* BITS_PER_U32 */ return -EINVAL; enabled_state = qcom_smem_state_get(dev, "ipa-clock-enabled", &enabled_bit); if (IS_ERR(enabled_state)) return PTR_ERR(enabled_state); if (enabled_bit >= 32) /* BITS_PER_U32 */ return -EINVAL; smp2p = kzalloc(sizeof(*smp2p), GFP_KERNEL); if (!smp2p) return -ENOMEM; smp2p->ipa = ipa; /* These fields are needed by the clock query interrupt * handler, so initialize them now. */ mutex_init(&smp2p->mutex); smp2p->valid_state = valid_state; smp2p->valid_bit = valid_bit; smp2p->enabled_state = enabled_state; smp2p->enabled_bit = enabled_bit; /* We have enough information saved to handle notifications */ ipa->smp2p = smp2p; ret = ipa_smp2p_irq_init(smp2p, "ipa-clock-query", ipa_smp2p_modem_clk_query_isr); if (ret < 0) goto err_null_smp2p; smp2p->clock_query_irq = ret; ret = ipa_smp2p_panic_notifier_register(smp2p); if (ret) goto err_irq_exit; if (modem_init) { /* Result will be non-zero (negative for error) */ ret = ipa_smp2p_irq_init(smp2p, "ipa-setup-ready", ipa_smp2p_modem_setup_ready_isr); if (ret < 0) goto err_notifier_unregister; smp2p->setup_ready_irq = ret; } return 0; err_notifier_unregister: ipa_smp2p_panic_notifier_unregister(smp2p); err_irq_exit: ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq); err_null_smp2p: ipa->smp2p = NULL; mutex_destroy(&smp2p->mutex); kfree(smp2p); return ret; } void ipa_smp2p_exit(struct ipa *ipa) { struct ipa_smp2p *smp2p = ipa->smp2p; if (smp2p->setup_ready_irq) ipa_smp2p_irq_exit(smp2p, smp2p->setup_ready_irq); ipa_smp2p_panic_notifier_unregister(smp2p); ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq); /* We won't get notified any more; drop clock reference (if any) */ ipa_smp2p_clock_release(ipa); ipa->smp2p = NULL; mutex_destroy(&smp2p->mutex); kfree(smp2p); } void ipa_smp2p_disable(struct ipa *ipa) { struct ipa_smp2p *smp2p = ipa->smp2p; if (!smp2p->setup_ready_irq) return; mutex_lock(&smp2p->mutex); smp2p->disabled = true; mutex_unlock(&smp2p->mutex); } /* Reset state tracking whether we have notified the modem */ void ipa_smp2p_notify_reset(struct ipa *ipa) { struct ipa_smp2p *smp2p = ipa->smp2p; u32 mask; if (!smp2p->notified) return; ipa_smp2p_clock_release(ipa); /* Reset the clock enabled valid flag */ mask = BIT(smp2p->valid_bit); qcom_smem_state_update_bits(smp2p->valid_state, mask, 0); /* Mark the clock disabled for good measure... */ mask = BIT(smp2p->enabled_bit); qcom_smem_state_update_bits(smp2p->enabled_state, mask, 0); smp2p->notified = false; }