Line data Source code
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 : */
23 : struct 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 */
32 : static 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 : */
39 : static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc)
40 : {
41 0 : u32 devid = desc->dev->msi.data->platform_data->devid;
42 :
43 0 : return (devid << (32 - DEV_ID_SHIFT)) | desc->msi_index;
44 : }
45 :
46 0 : static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
47 : {
48 0 : arg->desc = desc;
49 0 : arg->hwirq = platform_msi_calc_hwirq(desc);
50 0 : }
51 :
52 0 : static int platform_msi_init(struct irq_domain *domain,
53 : struct msi_domain_info *info,
54 : unsigned int virq, irq_hw_number_t hwirq,
55 : msi_alloc_info_t *arg)
56 : {
57 0 : return irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
58 0 : info->chip, info->chip_data);
59 : }
60 :
61 : static void platform_msi_set_proxy_dev(msi_alloc_info_t *arg)
62 : {
63 0 : arg->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE;
64 : }
65 : #else
66 : #define platform_msi_set_desc NULL
67 : #define platform_msi_init NULL
68 : #define platform_msi_set_proxy_dev(x) do {} while(0)
69 : #endif
70 :
71 0 : static void platform_msi_update_dom_ops(struct msi_domain_info *info)
72 : {
73 0 : struct msi_domain_ops *ops = info->ops;
74 :
75 0 : BUG_ON(!ops);
76 :
77 0 : if (ops->msi_init == NULL)
78 0 : ops->msi_init = platform_msi_init;
79 0 : if (ops->set_desc == NULL)
80 0 : ops->set_desc = platform_msi_set_desc;
81 0 : }
82 :
83 0 : static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
84 : {
85 0 : struct msi_desc *desc = irq_data_get_msi_desc(data);
86 :
87 0 : desc->dev->msi.data->platform_data->write_msg(desc, msg);
88 0 : }
89 :
90 0 : static void platform_msi_update_chip_ops(struct msi_domain_info *info)
91 : {
92 0 : struct irq_chip *chip = info->chip;
93 :
94 0 : BUG_ON(!chip);
95 0 : if (!chip->irq_mask)
96 0 : chip->irq_mask = irq_chip_mask_parent;
97 0 : if (!chip->irq_unmask)
98 0 : chip->irq_unmask = irq_chip_unmask_parent;
99 0 : if (!chip->irq_eoi)
100 0 : chip->irq_eoi = irq_chip_eoi_parent;
101 0 : if (!chip->irq_set_affinity)
102 0 : chip->irq_set_affinity = msi_domain_set_affinity;
103 0 : if (!chip->irq_write_msi_msg)
104 0 : chip->irq_write_msi_msg = platform_msi_write_msg;
105 0 : if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
106 : !(chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)))
107 0 : info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
108 0 : }
109 :
110 : /**
111 : * platform_msi_create_irq_domain - Create a platform MSI interrupt domain
112 : * @fwnode: Optional fwnode of the interrupt controller
113 : * @info: MSI domain info
114 : * @parent: Parent irq domain
115 : *
116 : * Updates the domain and chip ops and creates a platform MSI
117 : * interrupt domain.
118 : *
119 : * Returns:
120 : * A domain pointer or NULL in case of failure.
121 : */
122 0 : struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
123 : struct msi_domain_info *info,
124 : struct irq_domain *parent)
125 : {
126 : struct irq_domain *domain;
127 :
128 0 : if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
129 0 : platform_msi_update_dom_ops(info);
130 0 : if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
131 0 : platform_msi_update_chip_ops(info);
132 0 : info->flags |= MSI_FLAG_DEV_SYSFS | MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS |
133 : MSI_FLAG_FREE_MSI_DESCS;
134 :
135 0 : domain = msi_create_irq_domain(fwnode, info, parent);
136 0 : if (domain)
137 0 : irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI);
138 :
139 0 : return domain;
140 : }
141 : EXPORT_SYMBOL_GPL(platform_msi_create_irq_domain);
142 :
143 0 : static int platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
144 : irq_write_msi_msg_t write_msi_msg)
145 : {
146 : struct platform_msi_priv_data *datap;
147 : int err;
148 :
149 : /*
150 : * Limit the number of interrupts to 2048 per device. Should we
151 : * need to bump this up, DEV_ID_SHIFT should be adjusted
152 : * accordingly (which would impact the max number of MSI
153 : * capable devices).
154 : */
155 0 : if (!dev->msi.domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)
156 : return -EINVAL;
157 :
158 0 : if (dev->msi.domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
159 0 : dev_err(dev, "Incompatible msi_domain, giving up\n");
160 0 : return -EINVAL;
161 : }
162 :
163 0 : err = msi_setup_device_data(dev);
164 0 : if (err)
165 : return err;
166 :
167 : /* Already initialized? */
168 0 : if (dev->msi.data->platform_data)
169 : return -EBUSY;
170 :
171 0 : datap = kzalloc(sizeof(*datap), GFP_KERNEL);
172 0 : if (!datap)
173 : return -ENOMEM;
174 :
175 0 : datap->devid = ida_simple_get(&platform_msi_devid_ida,
176 : 0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
177 0 : if (datap->devid < 0) {
178 0 : err = datap->devid;
179 0 : kfree(datap);
180 0 : return err;
181 : }
182 :
183 0 : datap->write_msg = write_msi_msg;
184 0 : datap->dev = dev;
185 0 : dev->msi.data->platform_data = datap;
186 0 : return 0;
187 : }
188 :
189 0 : static void platform_msi_free_priv_data(struct device *dev)
190 : {
191 0 : struct platform_msi_priv_data *data = dev->msi.data->platform_data;
192 :
193 0 : dev->msi.data->platform_data = NULL;
194 0 : ida_simple_remove(&platform_msi_devid_ida, data->devid);
195 0 : kfree(data);
196 0 : }
197 :
198 : /**
199 : * platform_msi_domain_alloc_irqs - Allocate MSI interrupts for @dev
200 : * @dev: The device for which to allocate interrupts
201 : * @nvec: The number of interrupts to allocate
202 : * @write_msi_msg: Callback to write an interrupt message for @dev
203 : *
204 : * Returns:
205 : * Zero for success, or an error code in case of failure
206 : */
207 0 : int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
208 : irq_write_msi_msg_t write_msi_msg)
209 : {
210 : int err;
211 :
212 0 : err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
213 0 : if (err)
214 : return err;
215 :
216 0 : err = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1);
217 0 : if (err)
218 0 : platform_msi_free_priv_data(dev);
219 :
220 : return err;
221 : }
222 : EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs);
223 :
224 : /**
225 : * platform_msi_domain_free_irqs - Free MSI interrupts for @dev
226 : * @dev: The device for which to free interrupts
227 : */
228 0 : void platform_msi_domain_free_irqs(struct device *dev)
229 : {
230 0 : msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
231 0 : platform_msi_free_priv_data(dev);
232 0 : }
233 : EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs);
234 :
235 : /**
236 : * platform_msi_get_host_data - Query the private data associated with
237 : * a platform-msi domain
238 : * @domain: The platform-msi domain
239 : *
240 : * Return: The private data provided when calling
241 : * platform_msi_create_device_domain().
242 : */
243 0 : void *platform_msi_get_host_data(struct irq_domain *domain)
244 : {
245 0 : struct platform_msi_priv_data *data = domain->host_data;
246 :
247 0 : return data->host_data;
248 : }
249 :
250 : static struct lock_class_key platform_device_msi_lock_class;
251 :
252 : /**
253 : * __platform_msi_create_device_domain - Create a platform-msi device domain
254 : *
255 : * @dev: The device generating the MSIs
256 : * @nvec: The number of MSIs that need to be allocated
257 : * @is_tree: flag to indicate tree hierarchy
258 : * @write_msi_msg: Callback to write an interrupt message for @dev
259 : * @ops: The hierarchy domain operations to use
260 : * @host_data: Private data associated to this domain
261 : *
262 : * Return: An irqdomain for @nvec interrupts on success, NULL in case of error.
263 : *
264 : * This is for interrupt domains which stack on a platform-msi domain
265 : * created by platform_msi_create_irq_domain(). @dev->msi.domain points to
266 : * that platform-msi domain which is the parent for the new domain.
267 : */
268 : struct irq_domain *
269 0 : __platform_msi_create_device_domain(struct device *dev,
270 : unsigned int nvec,
271 : bool is_tree,
272 : irq_write_msi_msg_t write_msi_msg,
273 : const struct irq_domain_ops *ops,
274 : void *host_data)
275 : {
276 : struct platform_msi_priv_data *data;
277 : struct irq_domain *domain;
278 : int err;
279 :
280 0 : err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
281 0 : if (err)
282 : return NULL;
283 :
284 : /*
285 : * Use a separate lock class for the MSI descriptor mutex on
286 : * platform MSI device domains because the descriptor mutex nests
287 : * into the domain mutex. See alloc/free below.
288 : */
289 : lockdep_set_class(&dev->msi.data->mutex, &platform_device_msi_lock_class);
290 :
291 0 : data = dev->msi.data->platform_data;
292 0 : data->host_data = host_data;
293 0 : domain = irq_domain_create_hierarchy(dev->msi.domain, 0,
294 : is_tree ? 0 : nvec,
295 : dev->fwnode, ops, data);
296 0 : if (!domain)
297 : goto free_priv;
298 :
299 0 : platform_msi_set_proxy_dev(&data->arg);
300 0 : err = msi_domain_prepare_irqs(domain->parent, dev, nvec, &data->arg);
301 0 : if (err)
302 : goto free_domain;
303 :
304 : return domain;
305 :
306 : free_domain:
307 0 : irq_domain_remove(domain);
308 : free_priv:
309 0 : platform_msi_free_priv_data(dev);
310 0 : return NULL;
311 : }
312 :
313 : /**
314 : * platform_msi_device_domain_free - Free interrupts associated with a platform-msi
315 : * device domain
316 : *
317 : * @domain: The platform-msi device domain
318 : * @virq: The base irq from which to perform the free operation
319 : * @nr_irqs: How many interrupts to free from @virq
320 : */
321 0 : void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq,
322 : unsigned int nr_irqs)
323 : {
324 0 : struct platform_msi_priv_data *data = domain->host_data;
325 :
326 0 : msi_lock_descs(data->dev);
327 0 : msi_domain_depopulate_descs(data->dev, virq, nr_irqs);
328 0 : irq_domain_free_irqs_common(domain, virq, nr_irqs);
329 0 : msi_free_msi_descs_range(data->dev, virq, virq + nr_irqs - 1);
330 0 : msi_unlock_descs(data->dev);
331 0 : }
332 :
333 : /**
334 : * platform_msi_device_domain_alloc - Allocate interrupts associated with
335 : * a platform-msi device domain
336 : *
337 : * @domain: The platform-msi device domain
338 : * @virq: The base irq from which to perform the allocate operation
339 : * @nr_irqs: How many interrupts to allocate from @virq
340 : *
341 : * Return 0 on success, or an error code on failure. Must be called
342 : * with irq_domain_mutex held (which can only be done as part of a
343 : * top-level interrupt allocation).
344 : */
345 0 : int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int virq,
346 : unsigned int nr_irqs)
347 : {
348 0 : struct platform_msi_priv_data *data = domain->host_data;
349 0 : struct device *dev = data->dev;
350 :
351 0 : return msi_domain_populate_irqs(domain->parent, dev, virq, nr_irqs, &data->arg);
352 : }
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