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 | u32 devid = desc->dev->msi.data->platform_data->devid; |
42 | |
43 | return (devid << (32 - DEV_ID_SHIFT)) | desc->msi_index; |
44 | } |
45 | |
46 | static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc) |
47 | { |
48 | arg->desc = desc; |
49 | arg->hwirq = platform_msi_calc_hwirq(desc); |
50 | } |
51 | |
52 | 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 | return irq_domain_set_hwirq_and_chip(domain, virq, hwirq, |
58 | info->chip, info->chip_data); |
59 | } |
60 | |
61 | static void platform_msi_set_proxy_dev(msi_alloc_info_t *arg) |
62 | { |
63 | 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 | static void platform_msi_update_dom_ops(struct msi_domain_info *info) |
72 | { |
73 | struct msi_domain_ops *ops = info->ops; |
74 | |
75 | BUG_ON(!ops); |
76 | |
77 | if (ops->msi_init == NULL) |
78 | ops->msi_init = platform_msi_init; |
79 | if (ops->set_desc == NULL) |
80 | ops->set_desc = platform_msi_set_desc; |
81 | } |
82 | |
83 | static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg) |
84 | { |
85 | struct msi_desc *desc = irq_data_get_msi_desc(d: data); |
86 | |
87 | desc->dev->msi.data->platform_data->write_msg(desc, msg); |
88 | } |
89 | |
90 | static void platform_msi_update_chip_ops(struct msi_domain_info *info) |
91 | { |
92 | struct irq_chip *chip = info->chip; |
93 | |
94 | BUG_ON(!chip); |
95 | if (!chip->irq_mask) |
96 | chip->irq_mask = irq_chip_mask_parent; |
97 | if (!chip->irq_unmask) |
98 | chip->irq_unmask = irq_chip_unmask_parent; |
99 | if (!chip->irq_eoi) |
100 | chip->irq_eoi = irq_chip_eoi_parent; |
101 | if (!chip->irq_set_affinity) |
102 | chip->irq_set_affinity = msi_domain_set_affinity; |
103 | if (!chip->irq_write_msi_msg) |
104 | chip->irq_write_msi_msg = platform_msi_write_msg; |
105 | if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) && |
106 | !(chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI))) |
107 | info->flags &= ~MSI_FLAG_LEVEL_CAPABLE; |
108 | } |
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 | 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 | if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) |
129 | platform_msi_update_dom_ops(info); |
130 | if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) |
131 | platform_msi_update_chip_ops(info); |
132 | info->flags |= MSI_FLAG_DEV_SYSFS | MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | |
133 | MSI_FLAG_FREE_MSI_DESCS; |
134 | |
135 | domain = msi_create_irq_domain(fwnode, info, parent); |
136 | if (domain) |
137 | irq_domain_update_bus_token(domain, bus_token: DOMAIN_BUS_PLATFORM_MSI); |
138 | |
139 | return domain; |
140 | } |
141 | EXPORT_SYMBOL_GPL(platform_msi_create_irq_domain); |
142 | |
143 | 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 | if (!dev->msi.domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS) |
156 | return -EINVAL; |
157 | |
158 | if (dev->msi.domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) { |
159 | dev_err(dev, "Incompatible msi_domain, giving up\n" ); |
160 | return -EINVAL; |
161 | } |
162 | |
163 | err = msi_setup_device_data(dev); |
164 | if (err) |
165 | return err; |
166 | |
167 | /* Already initialized? */ |
168 | if (dev->msi.data->platform_data) |
169 | return -EBUSY; |
170 | |
171 | datap = kzalloc(size: sizeof(*datap), GFP_KERNEL); |
172 | if (!datap) |
173 | return -ENOMEM; |
174 | |
175 | datap->devid = ida_simple_get(&platform_msi_devid_ida, |
176 | 0, 1 << DEV_ID_SHIFT, GFP_KERNEL); |
177 | if (datap->devid < 0) { |
178 | err = datap->devid; |
179 | kfree(objp: datap); |
180 | return err; |
181 | } |
182 | |
183 | datap->write_msg = write_msi_msg; |
184 | datap->dev = dev; |
185 | dev->msi.data->platform_data = datap; |
186 | return 0; |
187 | } |
188 | |
189 | static void platform_msi_free_priv_data(struct device *dev) |
190 | { |
191 | struct platform_msi_priv_data *data = dev->msi.data->platform_data; |
192 | |
193 | dev->msi.data->platform_data = NULL; |
194 | ida_simple_remove(&platform_msi_devid_ida, data->devid); |
195 | kfree(objp: data); |
196 | } |
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 | 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 | err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); |
213 | if (err) |
214 | return err; |
215 | |
216 | err = msi_domain_alloc_irqs_range(dev, domid: MSI_DEFAULT_DOMAIN, first: 0, last: nvec - 1); |
217 | if (err) |
218 | 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 | void platform_msi_domain_free_irqs(struct device *dev) |
229 | { |
230 | msi_domain_free_irqs_all(dev, domid: MSI_DEFAULT_DOMAIN); |
231 | platform_msi_free_priv_data(dev); |
232 | } |
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 | void *platform_msi_get_host_data(struct irq_domain *domain) |
244 | { |
245 | struct platform_msi_priv_data *data = domain->host_data; |
246 | |
247 | 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 | __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 | err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); |
281 | 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 | data = dev->msi.data->platform_data; |
292 | data->host_data = host_data; |
293 | domain = irq_domain_create_hierarchy(parent: dev->msi.domain, flags: 0, |
294 | size: is_tree ? 0 : nvec, |
295 | fwnode: dev->fwnode, ops, host_data: data); |
296 | if (!domain) |
297 | goto free_priv; |
298 | |
299 | platform_msi_set_proxy_dev(&data->arg); |
300 | err = msi_domain_prepare_irqs(domain: domain->parent, dev, nvec, args: &data->arg); |
301 | if (err) |
302 | goto free_domain; |
303 | |
304 | return domain; |
305 | |
306 | free_domain: |
307 | irq_domain_remove(host: domain); |
308 | free_priv: |
309 | platform_msi_free_priv_data(dev); |
310 | 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 | void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq, |
322 | unsigned int nr_irqs) |
323 | { |
324 | struct platform_msi_priv_data *data = domain->host_data; |
325 | |
326 | msi_lock_descs(dev: data->dev); |
327 | msi_domain_depopulate_descs(dev: data->dev, virq, nvec: nr_irqs); |
328 | irq_domain_free_irqs_common(domain, virq, nr_irqs); |
329 | msi_free_msi_descs_range(dev: data->dev, first: virq, last: virq + nr_irqs - 1); |
330 | msi_unlock_descs(dev: data->dev); |
331 | } |
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 | int platform_msi_device_domain_alloc(struct irq_domain *domain, unsigned int virq, |
346 | unsigned int nr_irqs) |
347 | { |
348 | struct platform_msi_priv_data *data = domain->host_data; |
349 | struct device *dev = data->dev; |
350 | |
351 | return msi_domain_populate_irqs(domain: domain->parent, dev, virq, nvec: nr_irqs, args: &data->arg); |
352 | } |
353 | |