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 :
142 0 : static int platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
143 : irq_write_msi_msg_t write_msi_msg)
144 : {
145 : struct platform_msi_priv_data *datap;
146 : int err;
147 :
148 : /*
149 : * Limit the number of interrupts to 2048 per device. Should we
150 : * need to bump this up, DEV_ID_SHIFT should be adjusted
151 : * accordingly (which would impact the max number of MSI
152 : * capable devices).
153 : */
154 0 : if (!dev->msi.domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)
155 : return -EINVAL;
156 :
157 0 : if (dev->msi.domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
158 0 : dev_err(dev, "Incompatible msi_domain, giving up\n");
159 0 : return -EINVAL;
160 : }
161 :
162 0 : err = msi_setup_device_data(dev);
163 0 : if (err)
164 : return err;
165 :
166 : /* Already initialized? */
167 0 : if (dev->msi.data->platform_data)
168 : return -EBUSY;
169 :
170 0 : datap = kzalloc(sizeof(*datap), GFP_KERNEL);
171 0 : if (!datap)
172 : return -ENOMEM;
173 :
174 0 : datap->devid = ida_simple_get(&platform_msi_devid_ida,
175 : 0, 1 << DEV_ID_SHIFT, GFP_KERNEL);
176 0 : if (datap->devid < 0) {
177 0 : err = datap->devid;
178 0 : kfree(datap);
179 0 : return err;
180 : }
181 :
182 0 : datap->write_msg = write_msi_msg;
183 0 : datap->dev = dev;
184 0 : dev->msi.data->platform_data = datap;
185 0 : return 0;
186 : }
187 :
188 0 : static void platform_msi_free_priv_data(struct device *dev)
189 : {
190 0 : struct platform_msi_priv_data *data = dev->msi.data->platform_data;
191 :
192 0 : dev->msi.data->platform_data = NULL;
193 0 : ida_simple_remove(&platform_msi_devid_ida, data->devid);
194 0 : kfree(data);
195 0 : }
196 :
197 : /**
198 : * platform_msi_domain_alloc_irqs - Allocate MSI interrupts for @dev
199 : * @dev: The device for which to allocate interrupts
200 : * @nvec: The number of interrupts to allocate
201 : * @write_msi_msg: Callback to write an interrupt message for @dev
202 : *
203 : * Returns:
204 : * Zero for success, or an error code in case of failure
205 : */
206 0 : int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
207 : irq_write_msi_msg_t write_msi_msg)
208 : {
209 : int err;
210 :
211 0 : err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
212 0 : if (err)
213 : return err;
214 :
215 0 : err = msi_domain_alloc_irqs(dev->msi.domain, dev, nvec);
216 0 : if (err)
217 0 : platform_msi_free_priv_data(dev);
218 :
219 : return err;
220 : }
221 : EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs);
222 :
223 : /**
224 : * platform_msi_domain_free_irqs - Free MSI interrupts for @dev
225 : * @dev: The device for which to free interrupts
226 : */
227 0 : void platform_msi_domain_free_irqs(struct device *dev)
228 : {
229 0 : msi_domain_free_irqs(dev->msi.domain, dev);
230 0 : platform_msi_free_priv_data(dev);
231 0 : }
232 : EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs);
233 :
234 : /**
235 : * platform_msi_get_host_data - Query the private data associated with
236 : * a platform-msi domain
237 : * @domain: The platform-msi domain
238 : *
239 : * Return: The private data provided when calling
240 : * platform_msi_create_device_domain().
241 : */
242 0 : void *platform_msi_get_host_data(struct irq_domain *domain)
243 : {
244 0 : struct platform_msi_priv_data *data = domain->host_data;
245 :
246 0 : return data->host_data;
247 : }
248 :
249 : static struct lock_class_key platform_device_msi_lock_class;
250 :
251 : /**
252 : * __platform_msi_create_device_domain - Create a platform-msi device domain
253 : *
254 : * @dev: The device generating the MSIs
255 : * @nvec: The number of MSIs that need to be allocated
256 : * @is_tree: flag to indicate tree hierarchy
257 : * @write_msi_msg: Callback to write an interrupt message for @dev
258 : * @ops: The hierarchy domain operations to use
259 : * @host_data: Private data associated to this domain
260 : *
261 : * Return: An irqdomain for @nvec interrupts on success, NULL in case of error.
262 : *
263 : * This is for interrupt domains which stack on a platform-msi domain
264 : * created by platform_msi_create_irq_domain(). @dev->msi.domain points to
265 : * that platform-msi domain which is the parent for the new domain.
266 : */
267 : struct irq_domain *
268 0 : __platform_msi_create_device_domain(struct device *dev,
269 : unsigned int nvec,
270 : bool is_tree,
271 : irq_write_msi_msg_t write_msi_msg,
272 : const struct irq_domain_ops *ops,
273 : void *host_data)
274 : {
275 : struct platform_msi_priv_data *data;
276 : struct irq_domain *domain;
277 : int err;
278 :
279 0 : err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg);
280 0 : if (err)
281 : return NULL;
282 :
283 : /*
284 : * Use a separate lock class for the MSI descriptor mutex on
285 : * platform MSI device domains because the descriptor mutex nests
286 : * into the domain mutex. See alloc/free below.
287 : */
288 : lockdep_set_class(&dev->msi.data->mutex, &platform_device_msi_lock_class);
289 :
290 0 : data = dev->msi.data->platform_data;
291 0 : data->host_data = host_data;
292 0 : domain = irq_domain_create_hierarchy(dev->msi.domain, 0,
293 : is_tree ? 0 : nvec,
294 : dev->fwnode, ops, data);
295 0 : if (!domain)
296 : goto free_priv;
297 :
298 0 : platform_msi_set_proxy_dev(&data->arg);
299 0 : err = msi_domain_prepare_irqs(domain->parent, dev, nvec, &data->arg);
300 0 : if (err)
301 : goto free_domain;
302 :
303 : return domain;
304 :
305 : free_domain:
306 0 : irq_domain_remove(domain);
307 : free_priv:
308 0 : platform_msi_free_priv_data(dev);
309 0 : return NULL;
310 : }
311 :
312 : /**
313 : * platform_msi_device_domain_free - Free interrupts associated with a platform-msi
314 : * device domain
315 : *
316 : * @domain: The platform-msi device domain
317 : * @virq: The base irq from which to perform the free operation
318 : * @nr_irqs: How many interrupts to free from @virq
319 : */
320 0 : void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq,
321 : unsigned int nr_irqs)
322 : {
323 0 : struct platform_msi_priv_data *data = domain->host_data;
324 :
325 0 : msi_lock_descs(data->dev);
326 0 : irq_domain_free_irqs_common(domain, virq, nr_irqs);
327 0 : msi_free_msi_descs_range(data->dev, MSI_DESC_ALL, virq, virq + nr_irqs - 1);
328 0 : msi_unlock_descs(data->dev);
329 0 : }
330 :
331 : /**
332 : * platform_msi_device_domain_alloc - Allocate interrupts associated with
333 : * a platform-msi device domain
334 : *
335 : * @domain: The platform-msi device domain
336 : * @virq: The base irq from which to perform the allocate operation
337 : * @nr_irqs: How many interrupts to allocate from @virq
338 : *
339 : * Return 0 on success, or an error code on failure. Must be called
340 : * with irq_domain_mutex held (which can only be done as part of a
341 : * top-level interrupt allocation).
342 : */
343 0 : int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int virq,
344 : unsigned int nr_irqs)
345 : {
346 0 : struct platform_msi_priv_data *data = domain->host_data;
347 0 : struct device *dev = data->dev;
348 :
349 0 : return msi_domain_populate_irqs(domain->parent, dev, virq, nr_irqs, &data->arg);
350 : }
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