1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * ACPI helpers for DMA request / controller |
4 | * |
5 | * Based on of-dma.c |
6 | * |
7 | * Copyright (C) 2013, Intel Corporation |
8 | * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
9 | * Mika Westerberg <mika.westerberg@linux.intel.com> |
10 | */ |
11 | |
12 | #include <linux/device.h> |
13 | #include <linux/dma-mapping.h> |
14 | #include <linux/err.h> |
15 | #include <linux/module.h> |
16 | #include <linux/kernel.h> |
17 | #include <linux/list.h> |
18 | #include <linux/mutex.h> |
19 | #include <linux/slab.h> |
20 | #include <linux/ioport.h> |
21 | #include <linux/acpi.h> |
22 | #include <linux/acpi_dma.h> |
23 | #include <linux/property.h> |
24 | |
25 | static LIST_HEAD(acpi_dma_list); |
26 | static DEFINE_MUTEX(acpi_dma_lock); |
27 | |
28 | /** |
29 | * acpi_dma_parse_resource_group - match device and parse resource group |
30 | * @grp: CSRT resource group |
31 | * @adev: ACPI device to match with |
32 | * @adma: struct acpi_dma of the given DMA controller |
33 | * |
34 | * In order to match a device from DSDT table to the corresponding CSRT device |
35 | * we use MMIO address and IRQ. |
36 | * |
37 | * Return: |
38 | * 1 on success, 0 when no information is available, or appropriate errno value |
39 | * on error. |
40 | */ |
41 | static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, |
42 | struct acpi_device *adev, struct acpi_dma *adma) |
43 | { |
44 | const struct acpi_csrt_shared_info *si; |
45 | struct list_head resource_list; |
46 | struct resource_entry *rentry; |
47 | resource_size_t mem = 0, irq = 0; |
48 | int ret; |
49 | |
50 | if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info)) |
51 | return -ENODEV; |
52 | |
53 | INIT_LIST_HEAD(list: &resource_list); |
54 | ret = acpi_dev_get_resources(adev, list: &resource_list, NULL, NULL); |
55 | if (ret <= 0) |
56 | return 0; |
57 | |
58 | list_for_each_entry(rentry, &resource_list, node) { |
59 | if (resource_type(res: rentry->res) == IORESOURCE_MEM) |
60 | mem = rentry->res->start; |
61 | else if (resource_type(res: rentry->res) == IORESOURCE_IRQ) |
62 | irq = rentry->res->start; |
63 | } |
64 | |
65 | acpi_dev_free_resource_list(list: &resource_list); |
66 | |
67 | /* Consider initial zero values as resource not found */ |
68 | if (mem == 0 && irq == 0) |
69 | return 0; |
70 | |
71 | si = (const struct acpi_csrt_shared_info *)&grp[1]; |
72 | |
73 | /* Match device by MMIO */ |
74 | if (si->mmio_base_low != lower_32_bits(mem) || |
75 | si->mmio_base_high != upper_32_bits(mem)) |
76 | return 0; |
77 | |
78 | /* |
79 | * acpi_gsi_to_irq() can't be used because some platforms do not save |
80 | * registered IRQs in the MP table. Instead we just try to register |
81 | * the GSI, which is the core part of the above mentioned function. |
82 | */ |
83 | ret = acpi_register_gsi(NULL, gsi: si->gsi_interrupt, triggering: si->interrupt_mode, polarity: si->interrupt_polarity); |
84 | if (ret < 0) |
85 | return 0; |
86 | |
87 | /* Match device by Linux vIRQ */ |
88 | if (ret != irq) |
89 | return 0; |
90 | |
91 | dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n" , |
92 | (char *)&grp->vendor_id, grp->device_id, grp->revision); |
93 | |
94 | /* Check if the request line range is available */ |
95 | if (si->base_request_line == 0 && si->num_handshake_signals == 0) |
96 | return 0; |
97 | |
98 | /* Set up DMA mask based on value from CSRT */ |
99 | ret = dma_coerce_mask_and_coherent(dev: &adev->dev, |
100 | DMA_BIT_MASK(si->dma_address_width)); |
101 | if (ret) |
102 | return 0; |
103 | |
104 | adma->base_request_line = si->base_request_line; |
105 | adma->end_request_line = si->base_request_line + |
106 | si->num_handshake_signals - 1; |
107 | |
108 | dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n" , |
109 | adma->base_request_line, adma->end_request_line); |
110 | |
111 | return 1; |
112 | } |
113 | |
114 | /** |
115 | * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources |
116 | * @adev: ACPI device to match with |
117 | * @adma: struct acpi_dma of the given DMA controller |
118 | * |
119 | * CSRT or Core System Resources Table is a proprietary ACPI table |
120 | * introduced by Microsoft. This table can contain devices that are not in |
121 | * the system DSDT table. In particular DMA controllers might be described |
122 | * here. |
123 | * |
124 | * We are using this table to get the request line range of the specific DMA |
125 | * controller to be used later. |
126 | */ |
127 | static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma) |
128 | { |
129 | struct acpi_csrt_group *grp, *end; |
130 | struct acpi_table_csrt *csrt; |
131 | acpi_status status; |
132 | int ret; |
133 | |
134 | status = acpi_get_table(ACPI_SIG_CSRT, instance: 0, |
135 | out_table: (struct acpi_table_header **)&csrt); |
136 | if (ACPI_FAILURE(status)) { |
137 | if (status != AE_NOT_FOUND) |
138 | dev_warn(&adev->dev, "failed to get the CSRT table\n" ); |
139 | return; |
140 | } |
141 | |
142 | grp = (struct acpi_csrt_group *)(csrt + 1); |
143 | end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length); |
144 | |
145 | while (grp < end) { |
146 | ret = acpi_dma_parse_resource_group(grp, adev, adma); |
147 | if (ret < 0) { |
148 | dev_warn(&adev->dev, |
149 | "error in parsing resource group\n" ); |
150 | break; |
151 | } |
152 | |
153 | grp = (struct acpi_csrt_group *)((void *)grp + grp->length); |
154 | } |
155 | |
156 | acpi_put_table(table: (struct acpi_table_header *)csrt); |
157 | } |
158 | |
159 | /** |
160 | * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers |
161 | * @dev: struct device of DMA controller |
162 | * @acpi_dma_xlate: translation function which converts a dma specifier |
163 | * into a dma_chan structure |
164 | * @data: pointer to controller specific data to be used by |
165 | * translation function |
166 | * |
167 | * Allocated memory should be freed with appropriate acpi_dma_controller_free() |
168 | * call. |
169 | * |
170 | * Return: |
171 | * 0 on success or appropriate errno value on error. |
172 | */ |
173 | int acpi_dma_controller_register(struct device *dev, |
174 | struct dma_chan *(*acpi_dma_xlate) |
175 | (struct acpi_dma_spec *, struct acpi_dma *), |
176 | void *data) |
177 | { |
178 | struct acpi_device *adev; |
179 | struct acpi_dma *adma; |
180 | |
181 | if (!dev || !acpi_dma_xlate) |
182 | return -EINVAL; |
183 | |
184 | /* Check if the device was enumerated by ACPI */ |
185 | adev = ACPI_COMPANION(dev); |
186 | if (!adev) |
187 | return -EINVAL; |
188 | |
189 | adma = kzalloc(size: sizeof(*adma), GFP_KERNEL); |
190 | if (!adma) |
191 | return -ENOMEM; |
192 | |
193 | adma->dev = dev; |
194 | adma->acpi_dma_xlate = acpi_dma_xlate; |
195 | adma->data = data; |
196 | |
197 | acpi_dma_parse_csrt(adev, adma); |
198 | |
199 | /* Now queue acpi_dma controller structure in list */ |
200 | mutex_lock(&acpi_dma_lock); |
201 | list_add_tail(new: &adma->dma_controllers, head: &acpi_dma_list); |
202 | mutex_unlock(lock: &acpi_dma_lock); |
203 | |
204 | return 0; |
205 | } |
206 | EXPORT_SYMBOL_GPL(acpi_dma_controller_register); |
207 | |
208 | /** |
209 | * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list |
210 | * @dev: struct device of DMA controller |
211 | * |
212 | * Memory allocated by acpi_dma_controller_register() is freed here. |
213 | * |
214 | * Return: |
215 | * 0 on success or appropriate errno value on error. |
216 | */ |
217 | int acpi_dma_controller_free(struct device *dev) |
218 | { |
219 | struct acpi_dma *adma; |
220 | |
221 | if (!dev) |
222 | return -EINVAL; |
223 | |
224 | mutex_lock(&acpi_dma_lock); |
225 | |
226 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) |
227 | if (adma->dev == dev) { |
228 | list_del(entry: &adma->dma_controllers); |
229 | mutex_unlock(lock: &acpi_dma_lock); |
230 | kfree(objp: adma); |
231 | return 0; |
232 | } |
233 | |
234 | mutex_unlock(lock: &acpi_dma_lock); |
235 | return -ENODEV; |
236 | } |
237 | EXPORT_SYMBOL_GPL(acpi_dma_controller_free); |
238 | |
239 | static void devm_acpi_dma_release(struct device *dev, void *res) |
240 | { |
241 | acpi_dma_controller_free(dev); |
242 | } |
243 | |
244 | /** |
245 | * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register() |
246 | * @dev: device that is registering this DMA controller |
247 | * @acpi_dma_xlate: translation function |
248 | * @data: pointer to controller specific data |
249 | * |
250 | * Managed acpi_dma_controller_register(). DMA controller registered by this |
251 | * function are automatically freed on driver detach. See |
252 | * acpi_dma_controller_register() for more information. |
253 | * |
254 | * Return: |
255 | * 0 on success or appropriate errno value on error. |
256 | */ |
257 | int devm_acpi_dma_controller_register(struct device *dev, |
258 | struct dma_chan *(*acpi_dma_xlate) |
259 | (struct acpi_dma_spec *, struct acpi_dma *), |
260 | void *data) |
261 | { |
262 | void *res; |
263 | int ret; |
264 | |
265 | res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL); |
266 | if (!res) |
267 | return -ENOMEM; |
268 | |
269 | ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data); |
270 | if (ret) { |
271 | devres_free(res); |
272 | return ret; |
273 | } |
274 | devres_add(dev, res); |
275 | return 0; |
276 | } |
277 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register); |
278 | |
279 | /** |
280 | * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free() |
281 | * @dev: device that is unregistering as DMA controller |
282 | * |
283 | * Unregister a DMA controller registered with |
284 | * devm_acpi_dma_controller_register(). Normally this function will not need to |
285 | * be called and the resource management code will ensure that the resource is |
286 | * freed. |
287 | */ |
288 | void devm_acpi_dma_controller_free(struct device *dev) |
289 | { |
290 | WARN_ON(devres_release(dev, devm_acpi_dma_release, NULL, NULL)); |
291 | } |
292 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); |
293 | |
294 | /** |
295 | * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function |
296 | * @adma: struct acpi_dma of DMA controller |
297 | * @dma_spec: dma specifier to update |
298 | * |
299 | * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource |
300 | * Descriptor": |
301 | * DMA Request Line bits is a platform-relative number uniquely |
302 | * identifying the request line assigned. Request line-to-Controller |
303 | * mapping is done in a controller-specific OS driver. |
304 | * That's why we can safely adjust slave_id when the appropriate controller is |
305 | * found. |
306 | * |
307 | * Return: |
308 | * 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. |
309 | */ |
310 | static int acpi_dma_update_dma_spec(struct acpi_dma *adma, |
311 | struct acpi_dma_spec *dma_spec) |
312 | { |
313 | /* Set link to the DMA controller device */ |
314 | dma_spec->dev = adma->dev; |
315 | |
316 | /* Check if the request line range is available */ |
317 | if (adma->base_request_line == 0 && adma->end_request_line == 0) |
318 | return 0; |
319 | |
320 | /* Check if slave_id falls to the range */ |
321 | if (dma_spec->slave_id < adma->base_request_line || |
322 | dma_spec->slave_id > adma->end_request_line) |
323 | return -1; |
324 | |
325 | /* |
326 | * Here we adjust slave_id. It should be a relative number to the base |
327 | * request line. |
328 | */ |
329 | dma_spec->slave_id -= adma->base_request_line; |
330 | |
331 | return 1; |
332 | } |
333 | |
334 | struct acpi_dma_parser_data { |
335 | struct acpi_dma_spec dma_spec; |
336 | size_t index; |
337 | size_t n; |
338 | }; |
339 | |
340 | /** |
341 | * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier |
342 | * @res: struct acpi_resource to get FixedDMA resources from |
343 | * @data: pointer to a helper struct acpi_dma_parser_data |
344 | */ |
345 | static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) |
346 | { |
347 | struct acpi_dma_parser_data *pdata = data; |
348 | |
349 | if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) { |
350 | struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma; |
351 | |
352 | if (pdata->n++ == pdata->index) { |
353 | pdata->dma_spec.chan_id = dma->channels; |
354 | pdata->dma_spec.slave_id = dma->request_lines; |
355 | } |
356 | } |
357 | |
358 | /* Tell the ACPI core to skip this resource */ |
359 | return 1; |
360 | } |
361 | |
362 | /** |
363 | * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel |
364 | * @dev: struct device to get DMA request from |
365 | * @index: index of FixedDMA descriptor for @dev |
366 | * |
367 | * Return: |
368 | * Pointer to appropriate dma channel on success or an error pointer. |
369 | */ |
370 | struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, |
371 | size_t index) |
372 | { |
373 | struct acpi_dma_parser_data pdata; |
374 | struct acpi_dma_spec *dma_spec = &pdata.dma_spec; |
375 | struct acpi_device *adev = ACPI_COMPANION(dev); |
376 | struct list_head resource_list; |
377 | struct acpi_dma *adma; |
378 | struct dma_chan *chan = NULL; |
379 | int found; |
380 | int ret; |
381 | |
382 | memset(&pdata, 0, sizeof(pdata)); |
383 | pdata.index = index; |
384 | |
385 | /* Initial values for the request line and channel */ |
386 | dma_spec->chan_id = -1; |
387 | dma_spec->slave_id = -1; |
388 | |
389 | INIT_LIST_HEAD(list: &resource_list); |
390 | ret = acpi_dev_get_resources(adev, list: &resource_list, |
391 | preproc: acpi_dma_parse_fixed_dma, preproc_data: &pdata); |
392 | acpi_dev_free_resource_list(list: &resource_list); |
393 | if (ret < 0) |
394 | return ERR_PTR(error: ret); |
395 | |
396 | if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) |
397 | return ERR_PTR(error: -ENODEV); |
398 | |
399 | mutex_lock(&acpi_dma_lock); |
400 | |
401 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) { |
402 | /* |
403 | * We are not going to call translation function if slave_id |
404 | * doesn't fall to the request range. |
405 | */ |
406 | found = acpi_dma_update_dma_spec(adma, dma_spec); |
407 | if (found < 0) |
408 | continue; |
409 | chan = adma->acpi_dma_xlate(dma_spec, adma); |
410 | /* |
411 | * Try to get a channel only from the DMA controller that |
412 | * matches the slave_id. See acpi_dma_update_dma_spec() |
413 | * description for the details. |
414 | */ |
415 | if (found > 0 || chan) |
416 | break; |
417 | } |
418 | |
419 | mutex_unlock(lock: &acpi_dma_lock); |
420 | return chan ? chan : ERR_PTR(error: -EPROBE_DEFER); |
421 | } |
422 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); |
423 | |
424 | /** |
425 | * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel |
426 | * @dev: struct device to get DMA request from |
427 | * @name: represents corresponding FixedDMA descriptor for @dev |
428 | * |
429 | * In order to support both Device Tree and ACPI in a single driver we |
430 | * translate the names "tx" and "rx" here based on the most common case where |
431 | * the first FixedDMA descriptor is TX and second is RX. |
432 | * |
433 | * If the device has "dma-names" property the FixedDMA descriptor indices |
434 | * are retrieved based on those. Otherwise the function falls back using |
435 | * hardcoded indices. |
436 | * |
437 | * Return: |
438 | * Pointer to appropriate dma channel on success or an error pointer. |
439 | */ |
440 | struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, |
441 | const char *name) |
442 | { |
443 | int index; |
444 | |
445 | index = device_property_match_string(dev, propname: "dma-names" , string: name); |
446 | if (index < 0) { |
447 | if (!strcmp(name, "tx" )) |
448 | index = 0; |
449 | else if (!strcmp(name, "rx" )) |
450 | index = 1; |
451 | else |
452 | return ERR_PTR(error: -ENODEV); |
453 | } |
454 | |
455 | dev_dbg(dev, "Looking for DMA channel \"%s\" at index %d...\n" , name, index); |
456 | return acpi_dma_request_slave_chan_by_index(dev, index); |
457 | } |
458 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name); |
459 | |
460 | /** |
461 | * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper |
462 | * @dma_spec: pointer to ACPI DMA specifier |
463 | * @adma: pointer to ACPI DMA controller data |
464 | * |
465 | * A simple translation function for ACPI based devices. Passes &struct |
466 | * dma_spec to the DMA controller driver provided filter function. |
467 | * |
468 | * Return: |
469 | * Pointer to the channel if found or %NULL otherwise. |
470 | */ |
471 | struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, |
472 | struct acpi_dma *adma) |
473 | { |
474 | struct acpi_dma_filter_info *info = adma->data; |
475 | |
476 | if (!info || !info->filter_fn) |
477 | return NULL; |
478 | |
479 | return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec); |
480 | } |
481 | EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate); |
482 | |