| // SPDX-License-Identifier: GPL-2.0 |
| |
| /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. |
| * Copyright (C) 2019-2020 Linaro Ltd. |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/device.h> |
| #include <linux/interrupt.h> |
| #include <linux/notifier.h> |
| #include <linux/panic_notifier.h> |
| #include <linux/soc/qcom/smem.h> |
| #include <linux/soc/qcom/smem_state.h> |
| |
| #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 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) |
| 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; |
| } |