kernel/irq/irq_sim.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017-2018 Bartosz Golaszewski <[email protected]>
   4  * Copyright (C) 2020 Bartosz Golaszewski <[email protected]>
   5  */
   6
   7 #include <linux/cleanup.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/irq.h>
  10 #include <linux/irq_sim.h>
  11 #include <linux/irq_work.h>
  12 #include <linux/slab.h>
  13
  14 struct irq_sim_work_ctx {
  15         struct irq_work         work;
  16         unsigned int            irq_count;
  17         unsigned long           *pending;
  18         struct irq_domain       *domain;
  19         struct irq_sim_ops      ops;
  20         void                    *user_data;
  21 };
  22
  23 struct irq_sim_irq_ctx {
  24         bool                    enabled;
  25         struct irq_sim_work_ctx *work_ctx;
  26 };
  27
  28 static void irq_sim_irqmask(struct irq_data *data)
  29 {
  30         struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
  31
  32         irq_ctx->enabled = false;
  33 }
  34
  35 static void irq_sim_irqunmask(struct irq_data *data)
  36 {
  37         struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
  38
  39         irq_ctx->enabled = true;
  40 }
  41
  42 static int irq_sim_set_type(struct irq_data *data, unsigned int type)
  43 {
  44         /* We only support rising and falling edge trigger types. */
  45         if (type & ~IRQ_TYPE_EDGE_BOTH)
  46                 return -EINVAL;
  47
  48         irqd_set_trigger_type(data, type);
  49
  50         return 0;
  51 }
  52
  53 static int irq_sim_get_irqchip_state(struct irq_data *data,
  54                                      enum irqchip_irq_state which, bool *state)
  55 {
  56         struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
  57         irq_hw_number_t hwirq = irqd_to_hwirq(data);
  58
  59         switch (which) {
  60         case IRQCHIP_STATE_PENDING:
  61                 if (irq_ctx->enabled)
  62                         *state = test_bit(hwirq, irq_ctx->work_ctx->pending);
  63                 break;
  64         default:
  65                 return -EINVAL;
  66         }
  67
  68         return 0;
  69 }
  70
  71 static int irq_sim_set_irqchip_state(struct irq_data *data,
  72                                      enum irqchip_irq_state which, bool state)
  73 {
  74         struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
  75         irq_hw_number_t hwirq = irqd_to_hwirq(data);
  76
  77         switch (which) {
  78         case IRQCHIP_STATE_PENDING:
  79                 if (irq_ctx->enabled) {
  80                         assign_bit(hwirq, irq_ctx->work_ctx->pending, state);
  81                         if (state)
  82                                 irq_work_queue(&irq_ctx->work_ctx->work);
  83                 }
  84                 break;
  85         default:
  86                 return -EINVAL;
  87         }
  88
  89         return 0;
  90 }
  91
  92 static int irq_sim_request_resources(struct irq_data *data)
  93 {
  94         struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
  95         struct irq_sim_work_ctx *work_ctx = irq_ctx->work_ctx;
  96         irq_hw_number_t hwirq = irqd_to_hwirq(data);
  97
  98         if (work_ctx->ops.irq_sim_irq_requested)
  99                 return work_ctx->ops.irq_sim_irq_requested(work_ctx->domain,
 100                                                            hwirq,
 101                                                            work_ctx->user_data);
 102
 103         return 0;
 104 }
 105
 106 static void irq_sim_release_resources(struct irq_data *data)
 107 {
 108         struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
 109         struct irq_sim_work_ctx *work_ctx = irq_ctx->work_ctx;
 110         irq_hw_number_t hwirq = irqd_to_hwirq(data);
 111
 112         if (work_ctx->ops.irq_sim_irq_released)
 113                 work_ctx->ops.irq_sim_irq_released(work_ctx->domain, hwirq,
 114                                                    work_ctx->user_data);
 115 }
 116
 117 static struct irq_chip irq_sim_irqchip = {
 118         .name                   = "irq_sim",
 119         .irq_mask               = irq_sim_irqmask,
 120         .irq_unmask             = irq_sim_irqunmask,
 121         .irq_set_type           = irq_sim_set_type,
 122         .irq_get_irqchip_state  = irq_sim_get_irqchip_state,
 123         .irq_set_irqchip_state  = irq_sim_set_irqchip_state,
 124         .irq_request_resources  = irq_sim_request_resources,
 125         .irq_release_resources  = irq_sim_release_resources,
 126 };
 127
 128 static void irq_sim_handle_irq(struct irq_work *work)
 129 {
 130         struct irq_sim_work_ctx *work_ctx;
 131         unsigned int offset = 0;
 132         int irqnum;
 133
 134         work_ctx = container_of(work, struct irq_sim_work_ctx, work);
 135
 136         while (!bitmap_empty(work_ctx->pending, work_ctx->irq_count)) {
 137                 offset = find_next_bit(work_ctx->pending,
 138                                        work_ctx->irq_count, offset);
 139                 clear_bit(offset, work_ctx->pending);
 140                 irqnum = irq_find_mapping(work_ctx->domain, offset);
 141                 handle_simple_irq(irq_to_desc(irqnum));
 142         }
 143 }
 144
 145 static int irq_sim_domain_map(struct irq_domain *domain,
 146                               unsigned int virq, irq_hw_number_t hw)
 147 {
 148         struct irq_sim_work_ctx *work_ctx = domain->host_data;
 149         struct irq_sim_irq_ctx *irq_ctx;
 150
 151         irq_ctx = kzalloc(sizeof(*irq_ctx), GFP_KERNEL);
 152         if (!irq_ctx)
 153                 return -ENOMEM;
 154
 155         irq_set_chip(virq, &irq_sim_irqchip);
 156         irq_set_chip_data(virq, irq_ctx);
 157         irq_set_handler(virq, handle_simple_irq);
 158         irq_modify_status(virq, IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
 159         irq_ctx->work_ctx = work_ctx;
 160
 161         return 0;
 162 }
 163
 164 static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq)
 165 {
 166         struct irq_sim_irq_ctx *irq_ctx;
 167         struct irq_data *irqd;
 168
 169         irqd = irq_domain_get_irq_data(domain, virq);
 170         irq_ctx = irq_data_get_irq_chip_data(irqd);
 171
 172         irq_set_handler(virq, NULL);
 173         irq_domain_reset_irq_data(irqd);
 174         kfree(irq_ctx);
 175 }
 176
 177 static const struct irq_domain_ops irq_sim_domain_ops = {
 178         .map            = irq_sim_domain_map,
 179         .unmap          = irq_sim_domain_unmap,
 180 };
 181
 182 /**
 183  * irq_domain_create_sim - Create a new interrupt simulator irq_domain and
 184  *                         allocate a range of dummy interrupts.
 185  *
 186  * @fwnode:     struct fwnode_handle to be associated with this domain.
 187  * @num_irqs:   Number of interrupts to allocate.
 188  *
 189  * On success: return a new irq_domain object.
 190  * On failure: a negative errno wrapped with ERR_PTR().
 191  */
 192 struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
 193                                          unsigned int num_irqs)
 194 {
 195         return irq_domain_create_sim_full(fwnode, num_irqs, NULL, NULL);
 196 }
 197 EXPORT_SYMBOL_GPL(irq_domain_create_sim);
 198
 199 struct irq_domain *irq_domain_create_sim_full(struct fwnode_handle *fwnode,
 200                                               unsigned int num_irqs,
 201                                               const struct irq_sim_ops *ops,
 202                                               void *data)
 203 {
 204         struct irq_sim_work_ctx *work_ctx __free(kfree) =
 205                                 kmalloc(sizeof(*work_ctx), GFP_KERNEL);
 206
 207         if (!work_ctx)
 208                 return ERR_PTR(-ENOMEM);
 209
 210         unsigned long *pending __free(bitmap) = bitmap_zalloc(num_irqs, GFP_KERNEL);
 211         if (!pending)
 212                 return ERR_PTR(-ENOMEM);
 213
 214         work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs,
 215                                                     &irq_sim_domain_ops,
 216                                                     work_ctx);
 217         if (!work_ctx->domain)
 218                 return ERR_PTR(-ENOMEM);
 219
 220         work_ctx->irq_count = num_irqs;
 221         work_ctx->work = IRQ_WORK_INIT_HARD(irq_sim_handle_irq);
 222         work_ctx->pending = no_free_ptr(pending);
 223         work_ctx->user_data = data;
 224
 225         if (ops)
 226                 memcpy(&work_ctx->ops, ops, sizeof(*ops));
 227
 228         return no_free_ptr(work_ctx)->domain;
 229 }
 230 EXPORT_SYMBOL_GPL(irq_domain_create_sim_full);
 231
 232 /**
 233  * irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free
 234  *                         the interrupt descriptors and allocated memory.
 235  *
 236  * @domain:     The interrupt simulator domain to tear down.
 237  */
 238 void irq_domain_remove_sim(struct irq_domain *domain)
 239 {
 240         struct irq_sim_work_ctx *work_ctx = domain->host_data;
 241
 242         irq_work_sync(&work_ctx->work);
 243         bitmap_free(work_ctx->pending);
 244         kfree(work_ctx);
 245
 246         irq_domain_remove(domain);
 247 }
 248 EXPORT_SYMBOL_GPL(irq_domain_remove_sim);
 249
 250 static void devm_irq_domain_remove_sim(void *data)
 251 {
 252         struct irq_domain *domain = data;
 253
 254         irq_domain_remove_sim(domain);
 255 }
 256
 257 /**
 258  * devm_irq_domain_create_sim - Create a new interrupt simulator for
 259  *                              a managed device.
 260  *
 261  * @dev:        Device to initialize the simulator object for.
 262  * @fwnode:     struct fwnode_handle to be associated with this domain.
 263  * @num_irqs:   Number of interrupts to allocate
 264  *
 265  * On success: return a new irq_domain object.
 266  * On failure: a negative errno wrapped with ERR_PTR().
 267  */
 268 struct irq_domain *devm_irq_domain_create_sim(struct device *dev,
 269                                               struct fwnode_handle *fwnode,
 270                                               unsigned int num_irqs)
 271 {
 272         return devm_irq_domain_create_sim_full(dev, fwnode, num_irqs,
 273                                                NULL, NULL);
 274 }
 275 EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);
 276
 277 struct irq_domain *
 278 devm_irq_domain_create_sim_full(struct device *dev,
 279                                 struct fwnode_handle *fwnode,
 280                                 unsigned int num_irqs,
 281                                 const struct irq_sim_ops *ops,
 282                                 void *data)
 283 {
 284         struct irq_domain *domain;
 285         int ret;
 286
 287         domain = irq_domain_create_sim_full(fwnode, num_irqs, ops, data);
 288         if (IS_ERR(domain))
 289                 return domain;
 290
 291         ret = devm_add_action_or_reset(dev, devm_irq_domain_remove_sim, domain);
 292         if (ret)
 293                 return ERR_PTR(ret);
 294
 295         return domain;
 296 }
 297 EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim_full);