1// SPDX-License-Identifier: GPL-2.0 2/* 3 * MSI framework for platform devices 4 * 5 * Copyright (C) 2015 ARM Limited, All Rights Reserved. 6 * Author: Marc Zyngier <marc.zyngier@arm.com> 7 */ 8 9#include <linux/device.h> 10#include <linux/idr.h> 11#include <linux/irq.h> 12#include <linux/irqdomain.h> 13#include <linux/msi.h> 14#include <linux/slab.h> 15 16/* Begin of removal area. Once everything is converted over. Cleanup the includes too! */ 17 18#define DEV_ID_SHIFT 21 19#define MAX_DEV_MSIS (1 << (32 - DEV_ID_SHIFT)) 20 21/* 22 * Internal data structure containing a (made up, but unique) devid 23 * and the callback to write the MSI message. 24 */ 25struct platform_msi_priv_data { 26 struct device *dev; 27 void *host_data; 28 msi_alloc_info_t arg; 29 irq_write_msi_msg_t write_msg; 30 int devid; 31}; 32 33/* The devid allocator */ 34static DEFINE_IDA(platform_msi_devid_ida); 35 36#ifdef GENERIC_MSI_DOMAIN_OPS 37/* 38 * Convert an msi_desc to a globaly unique identifier (per-device 39 * devid + msi_desc position in the msi_list). 40 */ 41static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc) 42{ 43 u32 devid = desc->dev->msi.data->platform_data->devid; 44 45 return (devid << (32 - DEV_ID_SHIFT)) | desc->msi_index; 46} 47 48static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc) 49{ 50 arg->desc = desc; 51 arg->hwirq = platform_msi_calc_hwirq(desc); 52} 53 54static int platform_msi_init(struct irq_domain *domain, 55 struct msi_domain_info *info, 56 unsigned int virq, irq_hw_number_t hwirq, 57 msi_alloc_info_t *arg) 58{ 59 return irq_domain_set_hwirq_and_chip(domain, virq, hwirq, 60 info->chip, info->chip_data); 61} 62 63static void platform_msi_set_proxy_dev(msi_alloc_info_t *arg) 64{ 65 arg->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE; 66} 67#else 68#define platform_msi_set_desc NULL 69#define platform_msi_init NULL 70#define platform_msi_set_proxy_dev(x) do {} while(0) 71#endif 72 73static void platform_msi_update_dom_ops(struct msi_domain_info *info) 74{ 75 struct msi_domain_ops *ops = info->ops; 76 77 BUG_ON(!ops); 78 79 if (ops->msi_init == NULL) 80 ops->msi_init = platform_msi_init; 81 if (ops->set_desc == NULL) 82 ops->set_desc = platform_msi_set_desc; 83} 84 85static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg) 86{ 87 struct msi_desc *desc = irq_data_get_msi_desc(data); 88 89 desc->dev->msi.data->platform_data->write_msg(desc, msg); 90} 91 92static void platform_msi_update_chip_ops(struct msi_domain_info *info) 93{ 94 struct irq_chip *chip = info->chip; 95 96 BUG_ON(!chip); 97 if (!chip->irq_mask) 98 chip->irq_mask = irq_chip_mask_parent; 99 if (!chip->irq_unmask) 100 chip->irq_unmask = irq_chip_unmask_parent; 101 if (!chip->irq_eoi) 102 chip->irq_eoi = irq_chip_eoi_parent; 103 if (!chip->irq_set_affinity) 104 chip->irq_set_affinity = msi_domain_set_affinity; 105 if (!chip->irq_write_msi_msg) 106 chip->irq_write_msi_msg = platform_msi_write_msg; 107 if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) && 108 !(chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI))) 109 info->flags &= ~MSI_FLAG_LEVEL_CAPABLE; 110} 111 112/** 113 * platform_msi_create_irq_domain - Create a platform MSI interrupt domain 114 * @fwnode: Optional fwnode of the interrupt controller 115 * @info: MSI domain info 116 * @parent: Parent irq domain 117 * 118 * Updates the domain and chip ops and creates a platform MSI 119 * interrupt domain. 120 * 121 * Returns: 122 * A domain pointer or NULL in case of failure. 123 */ 124struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode, 125 struct msi_domain_info *info, 126 struct irq_domain *parent) 127{ 128 struct irq_domain *domain; 129 130 if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) 131 platform_msi_update_dom_ops(info); 132 if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) 133 platform_msi_update_chip_ops(info); 134 info->flags |= MSI_FLAG_DEV_SYSFS | MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | 135 MSI_FLAG_FREE_MSI_DESCS; 136 137 domain = msi_create_irq_domain(fwnode, info, parent); 138 if (domain) 139 irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI); 140 141 return domain; 142} 143EXPORT_SYMBOL_GPL(platform_msi_create_irq_domain); 144 145static int platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec, 146 irq_write_msi_msg_t write_msi_msg) 147{ 148 struct platform_msi_priv_data *datap; 149 int err; 150 151 /* 152 * Limit the number of interrupts to 2048 per device. Should we 153 * need to bump this up, DEV_ID_SHIFT should be adjusted 154 * accordingly (which would impact the max number of MSI 155 * capable devices). 156 */ 157 if (!dev->msi.domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS) 158 return -EINVAL; 159 160 if (dev->msi.domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) { 161 dev_err(dev, "Incompatible msi_domain, giving up\n"); 162 return -EINVAL; 163 } 164 165 err = msi_setup_device_data(dev); 166 if (err) 167 return err; 168 169 /* Already initialized? */ 170 if (dev->msi.data->platform_data) 171 return -EBUSY; 172 173 datap = kzalloc(sizeof(*datap), GFP_KERNEL); 174 if (!datap) 175 return -ENOMEM; 176 177 datap->devid = ida_alloc_max(&platform_msi_devid_ida, 178 (1 << DEV_ID_SHIFT) - 1, GFP_KERNEL); 179 if (datap->devid < 0) { 180 err = datap->devid; 181 kfree(datap); 182 return err; 183 } 184 185 datap->write_msg = write_msi_msg; 186 datap->dev = dev; 187 dev->msi.data->platform_data = datap; 188 return 0; 189} 190 191static void platform_msi_free_priv_data(struct device *dev) 192{ 193 struct platform_msi_priv_data *data = dev->msi.data->platform_data; 194 195 dev->msi.data->platform_data = NULL; 196 ida_free(&platform_msi_devid_ida, data->devid); 197 kfree(data); 198} 199 200/** 201 * platform_msi_domain_alloc_irqs - Allocate MSI interrupts for @dev 202 * @dev: The device for which to allocate interrupts 203 * @nvec: The number of interrupts to allocate 204 * @write_msi_msg: Callback to write an interrupt message for @dev 205 * 206 * Returns: 207 * Zero for success, or an error code in case of failure 208 */ 209static int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec, 210 irq_write_msi_msg_t write_msi_msg) 211{ 212 int err; 213 214 err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); 215 if (err) 216 return err; 217 218 err = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1); 219 if (err) 220 platform_msi_free_priv_data(dev); 221 222 return err; 223} 224 225/** 226 * platform_msi_get_host_data - Query the private data associated with 227 * a platform-msi domain 228 * @domain: The platform-msi domain 229 * 230 * Return: The private data provided when calling 231 * platform_msi_create_device_domain(). 232 */ 233void *platform_msi_get_host_data(struct irq_domain *domain) 234{ 235 struct platform_msi_priv_data *data = domain->host_data; 236 237 return data->host_data; 238} 239 240static struct lock_class_key platform_device_msi_lock_class; 241 242/** 243 * __platform_msi_create_device_domain - Create a platform-msi device domain 244 * 245 * @dev: The device generating the MSIs 246 * @nvec: The number of MSIs that need to be allocated 247 * @is_tree: flag to indicate tree hierarchy 248 * @write_msi_msg: Callback to write an interrupt message for @dev 249 * @ops: The hierarchy domain operations to use 250 * @host_data: Private data associated to this domain 251 * 252 * Return: An irqdomain for @nvec interrupts on success, NULL in case of error. 253 * 254 * This is for interrupt domains which stack on a platform-msi domain 255 * created by platform_msi_create_irq_domain(). @dev->msi.domain points to 256 * that platform-msi domain which is the parent for the new domain. 257 */ 258struct irq_domain * 259__platform_msi_create_device_domain(struct device *dev, 260 unsigned int nvec, 261 bool is_tree, 262 irq_write_msi_msg_t write_msi_msg, 263 const struct irq_domain_ops *ops, 264 void *host_data) 265{ 266 struct platform_msi_priv_data *data; 267 struct irq_domain *domain; 268 int err; 269 270 err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); 271 if (err) 272 return NULL; 273 274 /* 275 * Use a separate lock class for the MSI descriptor mutex on 276 * platform MSI device domains because the descriptor mutex nests 277 * into the domain mutex. See alloc/free below. 278 */ 279 lockdep_set_class(&dev->msi.data->mutex, &platform_device_msi_lock_class); 280 281 data = dev->msi.data->platform_data; 282 data->host_data = host_data; 283 domain = irq_domain_create_hierarchy(dev->msi.domain, 0, 284 is_tree ? 0 : nvec, 285 dev->fwnode, ops, data); 286 if (!domain) 287 goto free_priv; 288 289 platform_msi_set_proxy_dev(&data->arg); 290 err = msi_domain_prepare_irqs(domain->parent, dev, nvec, &data->arg); 291 if (err) 292 goto free_domain; 293 294 return domain; 295 296free_domain: 297 irq_domain_remove(domain); 298free_priv: 299 platform_msi_free_priv_data(dev); 300 return NULL; 301} 302 303/** 304 * platform_msi_device_domain_free - Free interrupts associated with a platform-msi 305 * device domain 306 * 307 * @domain: The platform-msi device domain 308 * @virq: The base irq from which to perform the free operation 309 * @nr_irqs: How many interrupts to free from @virq 310 */ 311void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq, 312 unsigned int nr_irqs) 313{ 314 struct platform_msi_priv_data *data = domain->host_data; 315 316 msi_lock_descs(data->dev); 317 msi_domain_depopulate_descs(data->dev, virq, nr_irqs); 318 irq_domain_free_irqs_common(domain, virq, nr_irqs); 319 msi_free_msi_descs_range(data->dev, virq, virq + nr_irqs - 1); 320 msi_unlock_descs(data->dev); 321} 322 323/** 324 * platform_msi_device_domain_alloc - Allocate interrupts associated with 325 * a platform-msi device domain 326 * 327 * @domain: The platform-msi device domain 328 * @virq: The base irq from which to perform the allocate operation 329 * @nr_irqs: How many interrupts to allocate from @virq 330 * 331 * Return 0 on success, or an error code on failure. Must be called 332 * with irq_domain_mutex held (which can only be done as part of a 333 * top-level interrupt allocation). 334 */ 335int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int virq, 336 unsigned int nr_irqs) 337{ 338 struct platform_msi_priv_data *data = domain->host_data; 339 struct device *dev = data->dev; 340 341 return msi_domain_populate_irqs(domain->parent, dev, virq, nr_irqs, &data->arg); 342} 343 344/* End of removal area */ 345 346/* Real per device domain interfaces */ 347 348/* 349 * This indirection can go when platform_device_msi_init_and_alloc_irqs() 350 * is switched to a proper irq_chip::irq_write_msi_msg() callback. Keep it 351 * simple for now. 352 */ 353static void platform_msi_write_msi_msg(struct irq_data *d, struct msi_msg *msg) 354{ 355 irq_write_msi_msg_t cb = d->chip_data; 356 357 cb(irq_data_get_msi_desc(d), msg); 358} 359 360static void platform_msi_set_desc_byindex(msi_alloc_info_t *arg, struct msi_desc *desc) 361{ 362 arg->desc = desc; 363 arg->hwirq = desc->msi_index; 364} 365 366static const struct msi_domain_template platform_msi_template = { 367 .chip = { 368 .name = "pMSI", 369 .irq_mask = irq_chip_mask_parent, 370 .irq_unmask = irq_chip_unmask_parent, 371 .irq_write_msi_msg = platform_msi_write_msi_msg, 372 /* The rest is filled in by the platform MSI parent */ 373 }, 374 375 .ops = { 376 .set_desc = platform_msi_set_desc_byindex, 377 }, 378 379 .info = { 380 .bus_token = DOMAIN_BUS_DEVICE_MSI, 381 }, 382}; 383 384/** 385 * platform_device_msi_init_and_alloc_irqs - Initialize platform device MSI 386 * and allocate interrupts for @dev 387 * @dev: The device for which to allocate interrupts 388 * @nvec: The number of interrupts to allocate 389 * @write_msi_msg: Callback to write an interrupt message for @dev 390 * 391 * Returns: 392 * Zero for success, or an error code in case of failure 393 * 394 * This creates a MSI domain on @dev which has @dev->msi.domain as 395 * parent. The parent domain sets up the new domain. The domain has 396 * a fixed size of @nvec. The domain is managed by devres and will 397 * be removed when the device is removed. 398 * 399 * Note: For migration purposes this falls back to the original platform_msi code 400 * up to the point where all platforms have been converted to the MSI 401 * parent model. 402 */ 403int platform_device_msi_init_and_alloc_irqs(struct device *dev, unsigned int nvec, 404 irq_write_msi_msg_t write_msi_msg) 405{ 406 struct irq_domain *domain = dev->msi.domain; 407 408 if (!domain || !write_msi_msg) 409 return -EINVAL; 410 411 /* Migration support. Will go away once everything is converted */ 412 if (!irq_domain_is_msi_parent(domain)) 413 return platform_msi_domain_alloc_irqs(dev, nvec, write_msi_msg); 414 415 /* 416 * @write_msi_msg is stored in the resulting msi_domain_info::data. 417 * The underlying domain creation mechanism will assign that 418 * callback to the resulting irq chip. 419 */ 420 if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN, 421 &platform_msi_template, 422 nvec, NULL, write_msi_msg)) 423 return -ENODEV; 424 425 return msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1); 426} 427EXPORT_SYMBOL_GPL(platform_device_msi_init_and_alloc_irqs); 428 429/** 430 * platform_device_msi_free_irqs_all - Free all interrupts for @dev 431 * @dev: The device for which to free interrupts 432 */ 433void platform_device_msi_free_irqs_all(struct device *dev) 434{ 435 struct irq_domain *domain = dev->msi.domain; 436 437 msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN); 438 439 /* Migration support. Will go away once everything is converted */ 440 if (!irq_domain_is_msi_parent(domain)) 441 platform_msi_free_priv_data(dev); 442} 443EXPORT_SYMBOL_GPL(platform_device_msi_free_irqs_all); 444