1 /* 2 * linux/kernel/irq/msi.c 3 * 4 * Copyright (C) 2014 Intel Corp. 5 * Author: Jiang Liu <jiang.liu@linux.intel.com> 6 * 7 * This file is licensed under GPLv2. 8 * 9 * This file contains common code to support Message Signalled Interrupt for 10 * PCI compatible and non PCI compatible devices. 11 */ 12 #include <linux/types.h> 13 #include <linux/device.h> 14 #include <linux/irq.h> 15 #include <linux/irqdomain.h> 16 #include <linux/msi.h> 17 18 /* Temparory solution for building, will be removed later */ 19 #include <linux/pci.h> 20 21 struct msi_desc *alloc_msi_entry(struct device *dev) 22 { 23 struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL); 24 if (!desc) 25 return NULL; 26 27 INIT_LIST_HEAD(&desc->list); 28 desc->dev = dev; 29 30 return desc; 31 } 32 33 void free_msi_entry(struct msi_desc *entry) 34 { 35 kfree(entry); 36 } 37 38 void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg) 39 { 40 *msg = entry->msg; 41 } 42 43 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) 44 { 45 struct msi_desc *entry = irq_get_msi_desc(irq); 46 47 __get_cached_msi_msg(entry, msg); 48 } 49 EXPORT_SYMBOL_GPL(get_cached_msi_msg); 50 51 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN 52 static inline void irq_chip_write_msi_msg(struct irq_data *data, 53 struct msi_msg *msg) 54 { 55 data->chip->irq_write_msi_msg(data, msg); 56 } 57 58 /** 59 * msi_domain_set_affinity - Generic affinity setter function for MSI domains 60 * @irq_data: The irq data associated to the interrupt 61 * @mask: The affinity mask to set 62 * @force: Flag to enforce setting (disable online checks) 63 * 64 * Intended to be used by MSI interrupt controllers which are 65 * implemented with hierarchical domains. 66 */ 67 int msi_domain_set_affinity(struct irq_data *irq_data, 68 const struct cpumask *mask, bool force) 69 { 70 struct irq_data *parent = irq_data->parent_data; 71 struct msi_msg msg; 72 int ret; 73 74 ret = parent->chip->irq_set_affinity(parent, mask, force); 75 if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) { 76 BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg)); 77 irq_chip_write_msi_msg(irq_data, &msg); 78 } 79 80 return ret; 81 } 82 83 static void msi_domain_activate(struct irq_domain *domain, 84 struct irq_data *irq_data) 85 { 86 struct msi_msg msg; 87 88 BUG_ON(irq_chip_compose_msi_msg(irq_data, &msg)); 89 irq_chip_write_msi_msg(irq_data, &msg); 90 } 91 92 static void msi_domain_deactivate(struct irq_domain *domain, 93 struct irq_data *irq_data) 94 { 95 struct msi_msg msg; 96 97 memset(&msg, 0, sizeof(msg)); 98 irq_chip_write_msi_msg(irq_data, &msg); 99 } 100 101 static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq, 102 unsigned int nr_irqs, void *arg) 103 { 104 struct msi_domain_info *info = domain->host_data; 105 struct msi_domain_ops *ops = info->ops; 106 irq_hw_number_t hwirq = ops->get_hwirq(info, arg); 107 int i, ret; 108 109 if (irq_find_mapping(domain, hwirq) > 0) 110 return -EEXIST; 111 112 if (domain->parent) { 113 ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg); 114 if (ret < 0) 115 return ret; 116 } 117 118 for (i = 0; i < nr_irqs; i++) { 119 ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg); 120 if (ret < 0) { 121 if (ops->msi_free) { 122 for (i--; i > 0; i--) 123 ops->msi_free(domain, info, virq + i); 124 } 125 irq_domain_free_irqs_top(domain, virq, nr_irqs); 126 return ret; 127 } 128 } 129 130 return 0; 131 } 132 133 static void msi_domain_free(struct irq_domain *domain, unsigned int virq, 134 unsigned int nr_irqs) 135 { 136 struct msi_domain_info *info = domain->host_data; 137 int i; 138 139 if (info->ops->msi_free) { 140 for (i = 0; i < nr_irqs; i++) 141 info->ops->msi_free(domain, info, virq + i); 142 } 143 irq_domain_free_irqs_top(domain, virq, nr_irqs); 144 } 145 146 static const struct irq_domain_ops msi_domain_ops = { 147 .alloc = msi_domain_alloc, 148 .free = msi_domain_free, 149 .activate = msi_domain_activate, 150 .deactivate = msi_domain_deactivate, 151 }; 152 153 #ifdef GENERIC_MSI_DOMAIN_OPS 154 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info, 155 msi_alloc_info_t *arg) 156 { 157 return arg->hwirq; 158 } 159 160 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev, 161 int nvec, msi_alloc_info_t *arg) 162 { 163 memset(arg, 0, sizeof(*arg)); 164 return 0; 165 } 166 167 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg, 168 struct msi_desc *desc) 169 { 170 arg->desc = desc; 171 } 172 #else 173 #define msi_domain_ops_get_hwirq NULL 174 #define msi_domain_ops_prepare NULL 175 #define msi_domain_ops_set_desc NULL 176 #endif /* !GENERIC_MSI_DOMAIN_OPS */ 177 178 static int msi_domain_ops_init(struct irq_domain *domain, 179 struct msi_domain_info *info, 180 unsigned int virq, irq_hw_number_t hwirq, 181 msi_alloc_info_t *arg) 182 { 183 irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip, 184 info->chip_data); 185 if (info->handler && info->handler_name) { 186 __irq_set_handler(virq, info->handler, 0, info->handler_name); 187 if (info->handler_data) 188 irq_set_handler_data(virq, info->handler_data); 189 } 190 return 0; 191 } 192 193 static int msi_domain_ops_check(struct irq_domain *domain, 194 struct msi_domain_info *info, 195 struct device *dev) 196 { 197 return 0; 198 } 199 200 static struct msi_domain_ops msi_domain_ops_default = { 201 .get_hwirq = msi_domain_ops_get_hwirq, 202 .msi_init = msi_domain_ops_init, 203 .msi_check = msi_domain_ops_check, 204 .msi_prepare = msi_domain_ops_prepare, 205 .set_desc = msi_domain_ops_set_desc, 206 }; 207 208 static void msi_domain_update_dom_ops(struct msi_domain_info *info) 209 { 210 struct msi_domain_ops *ops = info->ops; 211 212 if (ops == NULL) { 213 info->ops = &msi_domain_ops_default; 214 return; 215 } 216 217 if (ops->get_hwirq == NULL) 218 ops->get_hwirq = msi_domain_ops_default.get_hwirq; 219 if (ops->msi_init == NULL) 220 ops->msi_init = msi_domain_ops_default.msi_init; 221 if (ops->msi_check == NULL) 222 ops->msi_check = msi_domain_ops_default.msi_check; 223 if (ops->msi_prepare == NULL) 224 ops->msi_prepare = msi_domain_ops_default.msi_prepare; 225 if (ops->set_desc == NULL) 226 ops->set_desc = msi_domain_ops_default.set_desc; 227 } 228 229 static void msi_domain_update_chip_ops(struct msi_domain_info *info) 230 { 231 struct irq_chip *chip = info->chip; 232 233 BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask); 234 if (!chip->irq_set_affinity) 235 chip->irq_set_affinity = msi_domain_set_affinity; 236 } 237 238 /** 239 * msi_create_irq_domain - Create a MSI interrupt domain 240 * @fwnode: Optional fwnode of the interrupt controller 241 * @info: MSI domain info 242 * @parent: Parent irq domain 243 */ 244 struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode, 245 struct msi_domain_info *info, 246 struct irq_domain *parent) 247 { 248 if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) 249 msi_domain_update_dom_ops(info); 250 if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) 251 msi_domain_update_chip_ops(info); 252 253 return irq_domain_create_hierarchy(parent, 0, 0, fwnode, 254 &msi_domain_ops, info); 255 } 256 257 int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev, 258 int nvec, msi_alloc_info_t *arg) 259 { 260 struct msi_domain_info *info = domain->host_data; 261 struct msi_domain_ops *ops = info->ops; 262 int ret; 263 264 ret = ops->msi_check(domain, info, dev); 265 if (ret == 0) 266 ret = ops->msi_prepare(domain, dev, nvec, arg); 267 268 return ret; 269 } 270 271 int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev, 272 int virq, int nvec, msi_alloc_info_t *arg) 273 { 274 struct msi_domain_info *info = domain->host_data; 275 struct msi_domain_ops *ops = info->ops; 276 struct msi_desc *desc; 277 int ret = 0; 278 279 for_each_msi_entry(desc, dev) { 280 /* Don't even try the multi-MSI brain damage. */ 281 if (WARN_ON(!desc->irq || desc->nvec_used != 1)) { 282 ret = -EINVAL; 283 break; 284 } 285 286 if (!(desc->irq >= virq && desc->irq < (virq + nvec))) 287 continue; 288 289 ops->set_desc(arg, desc); 290 /* Assumes the domain mutex is held! */ 291 ret = irq_domain_alloc_irqs_recursive(domain, virq, 1, arg); 292 if (ret) 293 break; 294 295 irq_set_msi_desc_off(virq, 0, desc); 296 } 297 298 if (ret) { 299 /* Mop up the damage */ 300 for_each_msi_entry(desc, dev) { 301 if (!(desc->irq >= virq && desc->irq < (virq + nvec))) 302 continue; 303 304 irq_domain_free_irqs_common(domain, desc->irq, 1); 305 } 306 } 307 308 return ret; 309 } 310 311 /** 312 * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain 313 * @domain: The domain to allocate from 314 * @dev: Pointer to device struct of the device for which the interrupts 315 * are allocated 316 * @nvec: The number of interrupts to allocate 317 * 318 * Returns 0 on success or an error code. 319 */ 320 int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, 321 int nvec) 322 { 323 struct msi_domain_info *info = domain->host_data; 324 struct msi_domain_ops *ops = info->ops; 325 msi_alloc_info_t arg; 326 struct msi_desc *desc; 327 int i, ret, virq = -1; 328 329 ret = msi_domain_prepare_irqs(domain, dev, nvec, &arg); 330 if (ret) 331 return ret; 332 333 for_each_msi_entry(desc, dev) { 334 ops->set_desc(&arg, desc); 335 if (info->flags & MSI_FLAG_IDENTITY_MAP) 336 virq = (int)ops->get_hwirq(info, &arg); 337 else 338 virq = -1; 339 340 virq = __irq_domain_alloc_irqs(domain, virq, desc->nvec_used, 341 dev_to_node(dev), &arg, false); 342 if (virq < 0) { 343 ret = -ENOSPC; 344 if (ops->handle_error) 345 ret = ops->handle_error(domain, desc, ret); 346 if (ops->msi_finish) 347 ops->msi_finish(&arg, ret); 348 return ret; 349 } 350 351 for (i = 0; i < desc->nvec_used; i++) 352 irq_set_msi_desc_off(virq, i, desc); 353 } 354 355 if (ops->msi_finish) 356 ops->msi_finish(&arg, 0); 357 358 for_each_msi_entry(desc, dev) { 359 if (desc->nvec_used == 1) 360 dev_dbg(dev, "irq %d for MSI\n", virq); 361 else 362 dev_dbg(dev, "irq [%d-%d] for MSI\n", 363 virq, virq + desc->nvec_used - 1); 364 } 365 366 return 0; 367 } 368 369 /** 370 * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev 371 * @domain: The domain to managing the interrupts 372 * @dev: Pointer to device struct of the device for which the interrupts 373 * are free 374 */ 375 void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev) 376 { 377 struct msi_desc *desc; 378 379 for_each_msi_entry(desc, dev) { 380 /* 381 * We might have failed to allocate an MSI early 382 * enough that there is no IRQ associated to this 383 * entry. If that's the case, don't do anything. 384 */ 385 if (desc->irq) { 386 irq_domain_free_irqs(desc->irq, desc->nvec_used); 387 desc->irq = 0; 388 } 389 } 390 } 391 392 /** 393 * msi_get_domain_info - Get the MSI interrupt domain info for @domain 394 * @domain: The interrupt domain to retrieve data from 395 * 396 * Returns the pointer to the msi_domain_info stored in 397 * @domain->host_data. 398 */ 399 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain) 400 { 401 return (struct msi_domain_info *)domain->host_data; 402 } 403 404 #endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */ 405