Loading...
Note: File does not exist in v3.15.
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#define DEV_ID_SHIFT 21
17#define MAX_DEV_MSIS (1 << (32 - DEV_ID_SHIFT))
18
19/*
20 * Internal data structure containing a (made up, but unique) devid
21 * and the callback to write the MSI message.
22 */
23struct platform_msi_priv_data {
24 struct device *dev;
25 void *host_data;
26 msi_alloc_info_t arg;
27 irq_write_msi_msg_t write_msg;
28 int devid;
29};
30
31/* The devid allocator */
32static DEFINE_IDA(platform_msi_devid_ida);
33
34#ifdef GENERIC_MSI_DOMAIN_OPS
35/*
36 * Convert an msi_desc to a globaly unique identifier (per-device
37 * devid + msi_desc position in the msi_list).
38 */
39static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
40{
41 u32 devid;
42
43 devid = desc->platform.msi_priv_data->devid;
44
45 return (devid << (32 - DEV_ID_SHIFT)) | desc->platform.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 struct platform_msi_priv_data *priv_data;
89
90 priv_data = desc->platform.msi_priv_data;
91
92 priv_data->write_msg(desc, msg);
93}
94
95static void platform_msi_update_chip_ops(struct msi_domain_info *info)
96{
97 struct irq_chip *chip = info->chip;
98
99 BUG_ON(!chip);
100 if (!chip->irq_mask)
101 chip->irq_mask = irq_chip_mask_parent;
102 if (!chip->irq_unmask)
103 chip->irq_unmask = irq_chip_unmask_parent;
104 if (!chip->irq_eoi)
105 chip->irq_eoi = irq_chip_eoi_parent;
106 if (!chip->irq_set_affinity)
107 chip->irq_set_affinity = msi_domain_set_affinity;
108 if (!chip->irq_write_msi_msg)
109 chip->irq_write_msi_msg = platform_msi_write_msg;
110 if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
111 !(chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)))
112 info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
113}
114
115static void platform_msi_free_descs(struct device *dev, int base, int nvec)
116{
117 struct msi_desc *desc, *tmp;
118
119 list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {
120 if (desc->platform.msi_index >= base &&
121 desc->platform.msi_index < (base + nvec)) {
122 list_del(&desc->list);
123 free_msi_entry(desc);
124 }
125 }
126}
127
128static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
129 int nvec,
130 struct platform_msi_priv_data *data)
131
132{
133 struct msi_desc *desc;
134 int i, base = 0;
135
136 if (!list_empty(dev_to_msi_list(dev))) {
137 desc = list_last_entry(dev_to_msi_list(dev),
138 struct msi_desc, list);
139 base = desc->platform.msi_index + 1;
140 }
141
142 for (i = 0; i < nvec; i++) {
143 desc = alloc_msi_entry(dev, 1, NULL);
144 if (!desc)
145 break;
146
147 desc->platform.msi_priv_data = data;
148 desc->platform.msi_index = base + i;
149 desc->irq = virq ? virq + i : 0;
150
151 list_add_tail(&desc->list, dev_to_msi_list(dev));
152 }
153
154 if (i != nvec) {
155 /* Clean up the mess */
156 platform_msi_free_descs(dev, base, nvec);
157
158 return -ENOMEM;
159 }
160
161 return 0;
162}
163
164static int platform_msi_alloc_descs(struct device *dev, int nvec,
165 struct platform_msi_priv_data *data)
166
167{
168 return platform_msi_alloc_descs_with_irq(dev, 0, nvec, data);
169}
170
171/**
172 * platform_msi_create_irq_domain - Create a platform MSI interrupt domain
173 * @fwnode: Optional fwnode of the interrupt controller
174 * @info: MSI domain info
175 * @parent: Parent irq domain
176 *
177 * Updates the domain and chip ops and creates a platform MSI
178 * interrupt domain.
179 *
180 * Returns:
181 * A domain pointer or NULL in case of failure.
182 */
183struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
184 struct msi_domain_info *info,
185 struct irq_domain *parent)
186{
187 struct irq_domain *domain;
188
189 if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
190 platform_msi_update_dom_ops(info);
191 if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
192 platform_msi_update_chip_ops(info);
193
194 domain = msi_create_irq_domain(fwnode, info, parent);
195 if (domain)
196 irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI);
197
198 return domain;
199}
200
201static struct platform_msi_priv_data *
202platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
203 irq_write_msi_msg_t write_msi_msg)
204{
205 struct platform_msi_priv_data *datap;
206 /*
207 * Limit the number of interrupts to 2048 per device. Should we
208 * need to bump this up, DEV_ID_SHIFT should be adjusted
209 * accordingly (which would impact the max number of MSI
210 * capable devices).
211 */
212 if (!dev->msi_domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)
213 return ERR_PTR(-EINVAL);
214
215 if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
216 dev_err(dev, "Incompatible msi_domain, giving up\n");
217 return ERR_PTR(-EINVAL);
218 }
219
220 /* Already had a helping of MSI? Greed... */
221 if (!list_empty(dev_to_msi_list(dev)))
222 return ERR_PTR(-EBUSY);
223
224 datap = kzalloc(sizeof(*datap), GFP_KERNEL);
225 if (!datap)
226 return ERR_PTR(-ENOMEM);
227
228 datap->devid = ida_simple_get(&platform_msi_devid_ida,
229 0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
230 if (datap->devid < 0) {
231 int err = datap->devid;
232 kfree(datap);
233 return ERR_PTR(err);
234 }
235
236 datap->write_msg = write_msi_msg;
237 datap->dev = dev;
238
239 return datap;
240}
241
242static void platform_msi_free_priv_data(struct platform_msi_priv_data *data)
243{
244 ida_simple_remove(&platform_msi_devid_ida, data->devid);
245 kfree(data);
246}
247
248/**
249 * platform_msi_domain_alloc_irqs - Allocate MSI interrupts for @dev
250 * @dev: The device for which to allocate interrupts
251 * @nvec: The number of interrupts to allocate
252 * @write_msi_msg: Callback to write an interrupt message for @dev
253 *
254 * Returns:
255 * Zero for success, or an error code in case of failure
256 */
257int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
258 irq_write_msi_msg_t write_msi_msg)
259{
260 struct platform_msi_priv_data *priv_data;
261 int err;
262
263 priv_data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
264 if (IS_ERR(priv_data))
265 return PTR_ERR(priv_data);
266
267 err = platform_msi_alloc_descs(dev, nvec, priv_data);
268 if (err)
269 goto out_free_priv_data;
270
271 err = msi_domain_alloc_irqs(dev->msi_domain, dev, nvec);
272 if (err)
273 goto out_free_desc;
274
275 return 0;
276
277out_free_desc:
278 platform_msi_free_descs(dev, 0, nvec);
279out_free_priv_data:
280 platform_msi_free_priv_data(priv_data);
281
282 return err;
283}
284EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs);
285
286/**
287 * platform_msi_domain_free_irqs - Free MSI interrupts for @dev
288 * @dev: The device for which to free interrupts
289 */
290void platform_msi_domain_free_irqs(struct device *dev)
291{
292 if (!list_empty(dev_to_msi_list(dev))) {
293 struct msi_desc *desc;
294
295 desc = first_msi_entry(dev);
296 platform_msi_free_priv_data(desc->platform.msi_priv_data);
297 }
298
299 msi_domain_free_irqs(dev->msi_domain, dev);
300 platform_msi_free_descs(dev, 0, MAX_DEV_MSIS);
301}
302EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs);
303
304/**
305 * platform_msi_get_host_data - Query the private data associated with
306 * a platform-msi domain
307 * @domain: The platform-msi domain
308 *
309 * Returns the private data provided when calling
310 * platform_msi_create_device_domain.
311 */
312void *platform_msi_get_host_data(struct irq_domain *domain)
313{
314 struct platform_msi_priv_data *data = domain->host_data;
315 return data->host_data;
316}
317
318/**
319 * __platform_msi_create_device_domain - Create a platform-msi domain
320 *
321 * @dev: The device generating the MSIs
322 * @nvec: The number of MSIs that need to be allocated
323 * @is_tree: flag to indicate tree hierarchy
324 * @write_msi_msg: Callback to write an interrupt message for @dev
325 * @ops: The hierarchy domain operations to use
326 * @host_data: Private data associated to this domain
327 *
328 * Returns an irqdomain for @nvec interrupts
329 */
330struct irq_domain *
331__platform_msi_create_device_domain(struct device *dev,
332 unsigned int nvec,
333 bool is_tree,
334 irq_write_msi_msg_t write_msi_msg,
335 const struct irq_domain_ops *ops,
336 void *host_data)
337{
338 struct platform_msi_priv_data *data;
339 struct irq_domain *domain;
340 int err;
341
342 data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
343 if (IS_ERR(data))
344 return NULL;
345
346 data->host_data = host_data;
347 domain = irq_domain_create_hierarchy(dev->msi_domain, 0,
348 is_tree ? 0 : nvec,
349 dev->fwnode, ops, data);
350 if (!domain)
351 goto free_priv;
352
353 platform_msi_set_proxy_dev(&data->arg);
354 err = msi_domain_prepare_irqs(domain->parent, dev, nvec, &data->arg);
355 if (err)
356 goto free_domain;
357
358 return domain;
359
360free_domain:
361 irq_domain_remove(domain);
362free_priv:
363 platform_msi_free_priv_data(data);
364 return NULL;
365}
366
367/**
368 * platform_msi_domain_free - Free interrupts associated with a platform-msi
369 * domain
370 *
371 * @domain: The platform-msi domain
372 * @virq: The base irq from which to perform the free operation
373 * @nvec: How many interrupts to free from @virq
374 */
375void platform_msi_domain_free(struct irq_domain *domain, unsigned int virq,
376 unsigned int nvec)
377{
378 struct platform_msi_priv_data *data = domain->host_data;
379 struct msi_desc *desc, *tmp;
380 for_each_msi_entry_safe(desc, tmp, data->dev) {
381 if (WARN_ON(!desc->irq || desc->nvec_used != 1))
382 return;
383 if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
384 continue;
385
386 irq_domain_free_irqs_common(domain, desc->irq, 1);
387 list_del(&desc->list);
388 free_msi_entry(desc);
389 }
390}
391
392/**
393 * platform_msi_domain_alloc - Allocate interrupts associated with
394 * a platform-msi domain
395 *
396 * @domain: The platform-msi domain
397 * @virq: The base irq from which to perform the allocate operation
398 * @nr_irqs: How many interrupts to free from @virq
399 *
400 * Return 0 on success, or an error code on failure. Must be called
401 * with irq_domain_mutex held (which can only be done as part of a
402 * top-level interrupt allocation).
403 */
404int platform_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
405 unsigned int nr_irqs)
406{
407 struct platform_msi_priv_data *data = domain->host_data;
408 int err;
409
410 err = platform_msi_alloc_descs_with_irq(data->dev, virq, nr_irqs, data);
411 if (err)
412 return err;
413
414 err = msi_domain_populate_irqs(domain->parent, data->dev,
415 virq, nr_irqs, &data->arg);
416 if (err)
417 platform_msi_domain_free(domain, virq, nr_irqs);
418
419 return err;
420}