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1// SPDX-License-Identifier: GPL-2.02 3/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.4 * Copyright (C) 2019-2024 Linaro Ltd.5 */6 7#include <linux/interrupt.h>8#include <linux/notifier.h>9#include <linux/panic_notifier.h>10#include <linux/platform_device.h>11#include <linux/pm_runtime.h>12#include <linux/types.h>13 14#include <linux/soc/qcom/smem_state.h>15 16#include "ipa.h"17#include "ipa_smp2p.h"18#include "ipa_uc.h"19 20/**21 * DOC: IPA SMP2P communication with the modem22 *23 * SMP2P is a primitive communication mechanism available between the AP and24 * the modem. The IPA driver uses this for two purposes: to enable the modem25 * to state that the GSI hardware is ready to use; and to communicate the26 * state of IPA power in the event of a crash.27 *28 * GSI needs to have early initialization completed before it can be used.29 * This initialization is done either by Trust Zone or by the modem. In the30 * latter case, the modem uses an SMP2P interrupt to tell the AP IPA driver31 * when the GSI is ready to use.32 *33 * The modem is also able to inquire about the current state of IPA34 * power by trigging another SMP2P interrupt to the AP. We communicate35 * whether power is enabled using two SMP2P state bits--one to indicate36 * the power state (on or off), and a second to indicate the power state37 * bit is valid. The modem will poll the valid bit until it is set, and38 * at that time records whether the AP has IPA power enabled.39 *40 * Finally, if the AP kernel panics, we update the SMP2P state bits even if41 * we never receive an interrupt from the modem requesting this.42 */43 44/**45 * struct ipa_smp2p - IPA SMP2P information46 * @ipa: IPA pointer47 * @valid_state: SMEM state indicating enabled state is valid48 * @enabled_state: SMEM state to indicate power is enabled49 * @valid_bit: Valid bit in 32-bit SMEM state mask50 * @enabled_bit: Enabled bit in 32-bit SMEM state mask51 * @enabled_bit: Enabled bit in 32-bit SMEM state mask52 * @clock_query_irq: IPA interrupt triggered by modem for power query53 * @setup_ready_irq: IPA interrupt triggered by modem to signal GSI ready54 * @power_on: Whether IPA power is on55 * @notified: Whether modem has been notified of power state56 * @setup_disabled: Whether setup ready interrupt handler is disabled57 * @mutex: Mutex protecting ready-interrupt/shutdown interlock58 * @panic_notifier: Panic notifier structure59*/60struct ipa_smp2p {61 struct ipa *ipa;62 struct qcom_smem_state *valid_state;63 struct qcom_smem_state *enabled_state;64 u32 valid_bit;65 u32 enabled_bit;66 u32 clock_query_irq;67 u32 setup_ready_irq;68 bool power_on;69 bool notified;70 bool setup_disabled;71 struct mutex mutex;72 struct notifier_block panic_notifier;73};74 75/**76 * ipa_smp2p_notify() - use SMP2P to tell modem about IPA power state77 * @smp2p: SMP2P information78 *79 * This is called either when the modem has requested it (by triggering80 * the modem power query IPA interrupt) or whenever the AP is shutting down81 * (via a panic notifier). It sets the two SMP2P state bits--one saying82 * whether the IPA power is on, and the other indicating the first bit83 * is valid.84 */85static void ipa_smp2p_notify(struct ipa_smp2p *smp2p)86{87 u32 value;88 u32 mask;89 90 if (smp2p->notified)91 return;92 93 smp2p->power_on = pm_runtime_get_if_active(smp2p->ipa->dev) > 0;94 95 /* Signal whether the IPA power is enabled */96 mask = BIT(smp2p->enabled_bit);97 value = smp2p->power_on ? mask : 0;98 qcom_smem_state_update_bits(smp2p->enabled_state, mask, value);99 100 /* Now indicate that the enabled flag is valid */101 mask = BIT(smp2p->valid_bit);102 value = mask;103 qcom_smem_state_update_bits(smp2p->valid_state, mask, value);104 105 smp2p->notified = true;106}107 108/* Threaded IRQ handler for modem "ipa-clock-query" SMP2P interrupt */109static irqreturn_t ipa_smp2p_modem_clk_query_isr(int irq, void *dev_id)110{111 struct ipa_smp2p *smp2p = dev_id;112 113 ipa_smp2p_notify(smp2p);114 115 return IRQ_HANDLED;116}117 118static int ipa_smp2p_panic_notifier(struct notifier_block *nb,119 unsigned long action, void *data)120{121 struct ipa_smp2p *smp2p;122 123 smp2p = container_of(nb, struct ipa_smp2p, panic_notifier);124 125 ipa_smp2p_notify(smp2p);126 127 if (smp2p->power_on)128 ipa_uc_panic_notifier(smp2p->ipa);129 130 return NOTIFY_DONE;131}132 133static int ipa_smp2p_panic_notifier_register(struct ipa_smp2p *smp2p)134{135 /* IPA panic handler needs to run before modem shuts down */136 smp2p->panic_notifier.notifier_call = ipa_smp2p_panic_notifier;137 smp2p->panic_notifier.priority = INT_MAX; /* Do it early */138 139 return atomic_notifier_chain_register(&panic_notifier_list,140 &smp2p->panic_notifier);141}142 143static void ipa_smp2p_panic_notifier_unregister(struct ipa_smp2p *smp2p)144{145 atomic_notifier_chain_unregister(&panic_notifier_list,146 &smp2p->panic_notifier);147}148 149/* Threaded IRQ handler for modem "ipa-setup-ready" SMP2P interrupt */150static irqreturn_t ipa_smp2p_modem_setup_ready_isr(int irq, void *dev_id)151{152 struct ipa_smp2p *smp2p = dev_id;153 struct ipa *ipa = smp2p->ipa;154 struct device *dev;155 int ret;156 157 /* Ignore any (spurious) interrupts received after the first */158 if (ipa->setup_complete)159 return IRQ_HANDLED;160 161 /* Power needs to be active for setup */162 dev = ipa->dev;163 ret = pm_runtime_get_sync(dev);164 if (ret < 0) {165 dev_err(dev, "error %d getting power for setup\n", ret);166 goto out_power_put;167 }168 169 /* An error here won't cause driver shutdown, so warn if one occurs */170 ret = ipa_setup(ipa);171 WARN(ret != 0, "error %d from ipa_setup()\n", ret);172 173out_power_put:174 pm_runtime_mark_last_busy(dev);175 (void)pm_runtime_put_autosuspend(dev);176 177 return IRQ_HANDLED;178}179 180/* Initialize SMP2P interrupts */181static int ipa_smp2p_irq_init(struct ipa_smp2p *smp2p,182 struct platform_device *pdev,183 const char *name, irq_handler_t handler)184{185 struct device *dev = &pdev->dev;186 unsigned int irq;187 int ret;188 189 ret = platform_get_irq_byname(pdev, name);190 if (ret <= 0)191 return ret ? : -EINVAL;192 irq = ret;193 194 ret = request_threaded_irq(irq, NULL, handler, 0, name, smp2p);195 if (ret) {196 dev_err(dev, "error %d requesting \"%s\" IRQ\n", ret, name);197 return ret;198 }199 200 return irq;201}202 203static void ipa_smp2p_irq_exit(struct ipa_smp2p *smp2p, u32 irq)204{205 free_irq(irq, smp2p);206}207 208/* Drop the power reference if it was taken in ipa_smp2p_notify() */209static void ipa_smp2p_power_release(struct ipa *ipa)210{211 struct device *dev = ipa->dev;212 213 if (!ipa->smp2p->power_on)214 return;215 216 pm_runtime_mark_last_busy(dev);217 (void)pm_runtime_put_autosuspend(dev);218 ipa->smp2p->power_on = false;219}220 221/* Initialize the IPA SMP2P subsystem */222int223ipa_smp2p_init(struct ipa *ipa, struct platform_device *pdev, bool modem_init)224{225 struct qcom_smem_state *enabled_state;226 struct device *dev = &pdev->dev;227 struct qcom_smem_state *valid_state;228 struct ipa_smp2p *smp2p;229 u32 enabled_bit;230 u32 valid_bit;231 int ret;232 233 valid_state = qcom_smem_state_get(dev, "ipa-clock-enabled-valid",234 &valid_bit);235 if (IS_ERR(valid_state))236 return PTR_ERR(valid_state);237 if (valid_bit >= 32) /* BITS_PER_U32 */238 return -EINVAL;239 240 enabled_state = qcom_smem_state_get(dev, "ipa-clock-enabled",241 &enabled_bit);242 if (IS_ERR(enabled_state))243 return PTR_ERR(enabled_state);244 if (enabled_bit >= 32) /* BITS_PER_U32 */245 return -EINVAL;246 247 smp2p = kzalloc(sizeof(*smp2p), GFP_KERNEL);248 if (!smp2p)249 return -ENOMEM;250 251 smp2p->ipa = ipa;252 253 /* These fields are needed by the power query interrupt254 * handler, so initialize them now.255 */256 mutex_init(&smp2p->mutex);257 smp2p->valid_state = valid_state;258 smp2p->valid_bit = valid_bit;259 smp2p->enabled_state = enabled_state;260 smp2p->enabled_bit = enabled_bit;261 262 /* We have enough information saved to handle notifications */263 ipa->smp2p = smp2p;264 265 ret = ipa_smp2p_irq_init(smp2p, pdev, "ipa-clock-query",266 ipa_smp2p_modem_clk_query_isr);267 if (ret < 0)268 goto err_null_smp2p;269 smp2p->clock_query_irq = ret;270 271 ret = ipa_smp2p_panic_notifier_register(smp2p);272 if (ret)273 goto err_irq_exit;274 275 if (modem_init) {276 /* Result will be non-zero (negative for error) */277 ret = ipa_smp2p_irq_init(smp2p, pdev, "ipa-setup-ready",278 ipa_smp2p_modem_setup_ready_isr);279 if (ret < 0)280 goto err_notifier_unregister;281 smp2p->setup_ready_irq = ret;282 }283 284 return 0;285 286err_notifier_unregister:287 ipa_smp2p_panic_notifier_unregister(smp2p);288err_irq_exit:289 ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq);290err_null_smp2p:291 ipa->smp2p = NULL;292 mutex_destroy(&smp2p->mutex);293 kfree(smp2p);294 295 return ret;296}297 298void ipa_smp2p_exit(struct ipa *ipa)299{300 struct ipa_smp2p *smp2p = ipa->smp2p;301 302 if (smp2p->setup_ready_irq)303 ipa_smp2p_irq_exit(smp2p, smp2p->setup_ready_irq);304 ipa_smp2p_panic_notifier_unregister(smp2p);305 ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq);306 /* We won't get notified any more; drop power reference (if any) */307 ipa_smp2p_power_release(ipa);308 ipa->smp2p = NULL;309 mutex_destroy(&smp2p->mutex);310 kfree(smp2p);311}312 313void ipa_smp2p_irq_disable_setup(struct ipa *ipa)314{315 struct ipa_smp2p *smp2p = ipa->smp2p;316 317 if (!smp2p->setup_ready_irq)318 return;319 320 mutex_lock(&smp2p->mutex);321 322 if (!smp2p->setup_disabled) {323 disable_irq(smp2p->setup_ready_irq);324 smp2p->setup_disabled = true;325 }326 327 mutex_unlock(&smp2p->mutex);328}329 330/* Reset state tracking whether we have notified the modem */331void ipa_smp2p_notify_reset(struct ipa *ipa)332{333 struct ipa_smp2p *smp2p = ipa->smp2p;334 u32 mask;335 336 if (!smp2p->notified)337 return;338 339 ipa_smp2p_power_release(ipa);340 341 /* Reset the power enabled valid flag */342 mask = BIT(smp2p->valid_bit);343 qcom_smem_state_update_bits(smp2p->valid_state, mask, 0);344 345 /* Mark the power disabled for good measure... */346 mask = BIT(smp2p->enabled_bit);347 qcom_smem_state_update_bits(smp2p->enabled_state, mask, 0);348 349 smp2p->notified = false;350}351