1 // SPDX-License-Identifier: GPL-2.0 2 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 modem 22 * 23 * SMP2P is a primitive communication mechanism available between the AP and 24 * the modem. The IPA driver uses this for two purposes: to enable the modem 25 * to state that the GSI hardware is ready to use; and to communicate the 26 * 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 the 30 * latter case, the modem uses an SMP2P interrupt to tell the AP IPA driver 31 * when the GSI is ready to use. 32 * 33 * The modem is also able to inquire about the current state of IPA 34 * power by trigging another SMP2P interrupt to the AP. We communicate 35 * whether power is enabled using two SMP2P state bits--one to indicate 36 * the power state (on or off), and a second to indicate the power state 37 * bit is valid. The modem will poll the valid bit until it is set, and 38 * 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 if 41 * we never receive an interrupt from the modem requesting this. 42 */ 43 44 /** 45 * struct ipa_smp2p - IPA SMP2P information 46 * @ipa: IPA pointer 47 * @valid_state: SMEM state indicating enabled state is valid 48 * @enabled_state: SMEM state to indicate power is enabled 49 * @valid_bit: Valid bit in 32-bit SMEM state mask 50 * @enabled_bit: Enabled bit in 32-bit SMEM state mask 51 * @enabled_bit: Enabled bit in 32-bit SMEM state mask 52 * @clock_query_irq: IPA interrupt triggered by modem for power query 53 * @setup_ready_irq: IPA interrupt triggered by modem to signal GSI ready 54 * @power_on: Whether IPA power is on 55 * @notified: Whether modem has been notified of power state 56 * @setup_disabled: Whether setup ready interrupt handler is disabled 57 * @mutex: Mutex protecting ready-interrupt/shutdown interlock 58 * @panic_notifier: Panic notifier structure 59 */ 60 struct 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 state 77 * @smp2p: SMP2P information 78 * 79 * This is called either when the modem has requested it (by triggering 80 * the modem power query IPA interrupt) or whenever the AP is shutting down 81 * (via a panic notifier). It sets the two SMP2P state bits--one saying 82 * whether the IPA power is on, and the other indicating the first bit 83 * is valid. 84 */ 85 static 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 */ 109 static 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 } 117 118 static 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 } 132 133 static 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 } 142 143 static 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 */ 150 static 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); 172 173 out_power_put: 174 (void)pm_runtime_put_autosuspend(dev); 175 176 return IRQ_HANDLED; 177 } 178 179 /* Initialize SMP2P interrupts */ 180 static int ipa_smp2p_irq_init(struct ipa_smp2p *smp2p, 181 struct platform_device *pdev, 182 const char *name, irq_handler_t handler) 183 { 184 struct device *dev = &pdev->dev; 185 unsigned int irq; 186 int ret; 187 188 ret = platform_get_irq_byname(pdev, name); 189 if (ret <= 0) 190 return ret ? : -EINVAL; 191 irq = ret; 192 193 ret = request_threaded_irq(irq, NULL, handler, 0, name, smp2p); 194 if (ret) { 195 dev_err(dev, "error %d requesting \"%s\" IRQ\n", ret, name); 196 return ret; 197 } 198 199 return irq; 200 } 201 202 static void ipa_smp2p_irq_exit(struct ipa_smp2p *smp2p, u32 irq) 203 { 204 free_irq(irq, smp2p); 205 } 206 207 /* Drop the power reference if it was taken in ipa_smp2p_notify() */ 208 static void ipa_smp2p_power_release(struct ipa *ipa) 209 { 210 struct device *dev = ipa->dev; 211 212 if (!ipa->smp2p->power_on) 213 return; 214 215 (void)pm_runtime_put_autosuspend(dev); 216 ipa->smp2p->power_on = false; 217 } 218 219 /* Initialize the IPA SMP2P subsystem */ 220 int 221 ipa_smp2p_init(struct ipa *ipa, struct platform_device *pdev, bool modem_init) 222 { 223 struct qcom_smem_state *enabled_state; 224 struct device *dev = &pdev->dev; 225 struct qcom_smem_state *valid_state; 226 struct ipa_smp2p *smp2p; 227 u32 enabled_bit; 228 u32 valid_bit; 229 int ret; 230 231 valid_state = qcom_smem_state_get(dev, "ipa-clock-enabled-valid", 232 &valid_bit); 233 if (IS_ERR(valid_state)) 234 return PTR_ERR(valid_state); 235 if (valid_bit >= 32) { /* BITS_PER_U32 */ 236 ret = -EINVAL; 237 goto err_valid_state_put; 238 } 239 240 enabled_state = qcom_smem_state_get(dev, "ipa-clock-enabled", 241 &enabled_bit); 242 if (IS_ERR(enabled_state)) { 243 ret = PTR_ERR(enabled_state); 244 goto err_valid_state_put; 245 } 246 if (enabled_bit >= 32) { /* BITS_PER_U32 */ 247 ret = -EINVAL; 248 goto err_enabled_state_put; 249 } 250 251 smp2p = kzalloc_obj(*smp2p); 252 if (!smp2p) { 253 ret = -ENOMEM; 254 goto err_enabled_state_put; 255 } 256 257 smp2p->ipa = ipa; 258 259 /* These fields are needed by the power query interrupt 260 * handler, so initialize them now. 261 */ 262 mutex_init(&smp2p->mutex); 263 smp2p->valid_state = valid_state; 264 smp2p->valid_bit = valid_bit; 265 smp2p->enabled_state = enabled_state; 266 smp2p->enabled_bit = enabled_bit; 267 268 /* We have enough information saved to handle notifications */ 269 ipa->smp2p = smp2p; 270 271 ret = ipa_smp2p_irq_init(smp2p, pdev, "ipa-clock-query", 272 ipa_smp2p_modem_clk_query_isr); 273 if (ret < 0) 274 goto err_null_smp2p; 275 smp2p->clock_query_irq = ret; 276 277 ret = ipa_smp2p_panic_notifier_register(smp2p); 278 if (ret) 279 goto err_irq_exit; 280 281 if (modem_init) { 282 /* Result will be non-zero (negative for error) */ 283 ret = ipa_smp2p_irq_init(smp2p, pdev, "ipa-setup-ready", 284 ipa_smp2p_modem_setup_ready_isr); 285 if (ret < 0) 286 goto err_notifier_unregister; 287 smp2p->setup_ready_irq = ret; 288 } 289 290 return 0; 291 292 err_notifier_unregister: 293 ipa_smp2p_panic_notifier_unregister(smp2p); 294 err_irq_exit: 295 ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq); 296 err_null_smp2p: 297 ipa->smp2p = NULL; 298 mutex_destroy(&smp2p->mutex); 299 kfree(smp2p); 300 err_enabled_state_put: 301 qcom_smem_state_put(enabled_state); 302 err_valid_state_put: 303 qcom_smem_state_put(valid_state); 304 305 return ret; 306 } 307 308 void ipa_smp2p_exit(struct ipa *ipa) 309 { 310 struct ipa_smp2p *smp2p = ipa->smp2p; 311 312 if (smp2p->setup_ready_irq) 313 ipa_smp2p_irq_exit(smp2p, smp2p->setup_ready_irq); 314 ipa_smp2p_panic_notifier_unregister(smp2p); 315 ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq); 316 /* We won't get notified any more; drop power reference (if any) */ 317 ipa_smp2p_power_release(ipa); 318 ipa->smp2p = NULL; 319 mutex_destroy(&smp2p->mutex); 320 qcom_smem_state_put(smp2p->enabled_state); 321 qcom_smem_state_put(smp2p->valid_state); 322 kfree(smp2p); 323 } 324 325 void ipa_smp2p_irq_disable_setup(struct ipa *ipa) 326 { 327 struct ipa_smp2p *smp2p = ipa->smp2p; 328 329 if (!smp2p->setup_ready_irq) 330 return; 331 332 mutex_lock(&smp2p->mutex); 333 334 if (!smp2p->setup_disabled) { 335 disable_irq(smp2p->setup_ready_irq); 336 smp2p->setup_disabled = true; 337 } 338 339 mutex_unlock(&smp2p->mutex); 340 } 341 342 /* Reset state tracking whether we have notified the modem */ 343 void ipa_smp2p_notify_reset(struct ipa *ipa) 344 { 345 struct ipa_smp2p *smp2p = ipa->smp2p; 346 u32 mask; 347 348 if (!smp2p->notified) 349 return; 350 351 ipa_smp2p_power_release(ipa); 352 353 /* Reset the power enabled valid flag */ 354 mask = BIT(smp2p->valid_bit); 355 qcom_smem_state_update_bits(smp2p->valid_state, mask, 0); 356 357 /* Mark the power disabled for good measure... */ 358 mask = BIT(smp2p->enabled_bit); 359 qcom_smem_state_update_bits(smp2p->enabled_state, mask, 0); 360 361 smp2p->notified = false; 362 } 363