ACPI / scan: Remove unnecessary initialization of local variables
[linux-3.10.git] / drivers / acpi / resource.c
1 /*
2  * drivers/acpi/resource.c - ACPI device resources interpretation.
3  *
4  * Copyright (C) 2012, Intel Corp.
5  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6  *
7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2 as published
11  *  by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful, but
14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  *  General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License along
19  *  with this program; if not, write to the Free Software Foundation, Inc.,
20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21  *
22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23  */
24
25 #include <linux/acpi.h>
26 #include <linux/device.h>
27 #include <linux/export.h>
28 #include <linux/ioport.h>
29 #include <linux/slab.h>
30
31 #ifdef CONFIG_X86
32 #define valid_IRQ(i) (((i) != 0) && ((i) != 2))
33 #else
34 #define valid_IRQ(i) (true)
35 #endif
36
37 static unsigned long acpi_dev_memresource_flags(u64 len, u8 write_protect,
38                                                 bool window)
39 {
40         unsigned long flags = IORESOURCE_MEM;
41
42         if (len == 0)
43                 flags |= IORESOURCE_DISABLED;
44
45         if (write_protect == ACPI_READ_WRITE_MEMORY)
46                 flags |= IORESOURCE_MEM_WRITEABLE;
47
48         if (window)
49                 flags |= IORESOURCE_WINDOW;
50
51         return flags;
52 }
53
54 static void acpi_dev_get_memresource(struct resource *res, u64 start, u64 len,
55                                      u8 write_protect)
56 {
57         res->start = start;
58         res->end = start + len - 1;
59         res->flags = acpi_dev_memresource_flags(len, write_protect, false);
60 }
61
62 /**
63  * acpi_dev_resource_memory - Extract ACPI memory resource information.
64  * @ares: Input ACPI resource object.
65  * @res: Output generic resource object.
66  *
67  * Check if the given ACPI resource object represents a memory resource and
68  * if that's the case, use the information in it to populate the generic
69  * resource object pointed to by @res.
70  */
71 bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
72 {
73         struct acpi_resource_memory24 *memory24;
74         struct acpi_resource_memory32 *memory32;
75         struct acpi_resource_fixed_memory32 *fixed_memory32;
76
77         switch (ares->type) {
78         case ACPI_RESOURCE_TYPE_MEMORY24:
79                 memory24 = &ares->data.memory24;
80                 acpi_dev_get_memresource(res, memory24->minimum,
81                                          memory24->address_length,
82                                          memory24->write_protect);
83                 break;
84         case ACPI_RESOURCE_TYPE_MEMORY32:
85                 memory32 = &ares->data.memory32;
86                 acpi_dev_get_memresource(res, memory32->minimum,
87                                          memory32->address_length,
88                                          memory32->write_protect);
89                 break;
90         case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
91                 fixed_memory32 = &ares->data.fixed_memory32;
92                 acpi_dev_get_memresource(res, fixed_memory32->address,
93                                          fixed_memory32->address_length,
94                                          fixed_memory32->write_protect);
95                 break;
96         default:
97                 return false;
98         }
99         return true;
100 }
101 EXPORT_SYMBOL_GPL(acpi_dev_resource_memory);
102
103 static unsigned int acpi_dev_ioresource_flags(u64 start, u64 end, u8 io_decode,
104                                               bool window)
105 {
106         int flags = IORESOURCE_IO;
107
108         if (io_decode == ACPI_DECODE_16)
109                 flags |= IORESOURCE_IO_16BIT_ADDR;
110
111         if (start > end || end >= 0x10003)
112                 flags |= IORESOURCE_DISABLED;
113
114         if (window)
115                 flags |= IORESOURCE_WINDOW;
116
117         return flags;
118 }
119
120 static void acpi_dev_get_ioresource(struct resource *res, u64 start, u64 len,
121                                     u8 io_decode)
122 {
123         u64 end = start + len - 1;
124
125         res->start = start;
126         res->end = end;
127         res->flags = acpi_dev_ioresource_flags(start, end, io_decode, false);
128 }
129
130 /**
131  * acpi_dev_resource_io - Extract ACPI I/O resource information.
132  * @ares: Input ACPI resource object.
133  * @res: Output generic resource object.
134  *
135  * Check if the given ACPI resource object represents an I/O resource and
136  * if that's the case, use the information in it to populate the generic
137  * resource object pointed to by @res.
138  */
139 bool acpi_dev_resource_io(struct acpi_resource *ares, struct resource *res)
140 {
141         struct acpi_resource_io *io;
142         struct acpi_resource_fixed_io *fixed_io;
143
144         switch (ares->type) {
145         case ACPI_RESOURCE_TYPE_IO:
146                 io = &ares->data.io;
147                 acpi_dev_get_ioresource(res, io->minimum,
148                                         io->address_length,
149                                         io->io_decode);
150                 break;
151         case ACPI_RESOURCE_TYPE_FIXED_IO:
152                 fixed_io = &ares->data.fixed_io;
153                 acpi_dev_get_ioresource(res, fixed_io->address,
154                                         fixed_io->address_length,
155                                         ACPI_DECODE_10);
156                 break;
157         default:
158                 return false;
159         }
160         return true;
161 }
162 EXPORT_SYMBOL_GPL(acpi_dev_resource_io);
163
164 /**
165  * acpi_dev_resource_address_space - Extract ACPI address space information.
166  * @ares: Input ACPI resource object.
167  * @res: Output generic resource object.
168  *
169  * Check if the given ACPI resource object represents an address space resource
170  * and if that's the case, use the information in it to populate the generic
171  * resource object pointed to by @res.
172  */
173 bool acpi_dev_resource_address_space(struct acpi_resource *ares,
174                                      struct resource *res)
175 {
176         acpi_status status;
177         struct acpi_resource_address64 addr;
178         bool window;
179         u64 len;
180         u8 io_decode;
181
182         switch (ares->type) {
183         case ACPI_RESOURCE_TYPE_ADDRESS16:
184         case ACPI_RESOURCE_TYPE_ADDRESS32:
185         case ACPI_RESOURCE_TYPE_ADDRESS64:
186                 break;
187         default:
188                 return false;
189         }
190
191         status = acpi_resource_to_address64(ares, &addr);
192         if (ACPI_FAILURE(status))
193                 return true;
194
195         res->start = addr.minimum;
196         res->end = addr.maximum;
197         window = addr.producer_consumer == ACPI_PRODUCER;
198
199         switch(addr.resource_type) {
200         case ACPI_MEMORY_RANGE:
201                 len = addr.maximum - addr.minimum + 1;
202                 res->flags = acpi_dev_memresource_flags(len,
203                                                 addr.info.mem.write_protect,
204                                                 window);
205                 break;
206         case ACPI_IO_RANGE:
207                 io_decode = addr.granularity == 0xfff ?
208                                 ACPI_DECODE_10 : ACPI_DECODE_16;
209                 res->flags = acpi_dev_ioresource_flags(addr.minimum,
210                                                        addr.maximum,
211                                                        io_decode, window);
212                 break;
213         case ACPI_BUS_NUMBER_RANGE:
214                 res->flags = IORESOURCE_BUS;
215                 break;
216         default:
217                 res->flags = 0;
218         }
219
220         return true;
221 }
222 EXPORT_SYMBOL_GPL(acpi_dev_resource_address_space);
223
224 /**
225  * acpi_dev_resource_ext_address_space - Extract ACPI address space information.
226  * @ares: Input ACPI resource object.
227  * @res: Output generic resource object.
228  *
229  * Check if the given ACPI resource object represents an extended address space
230  * resource and if that's the case, use the information in it to populate the
231  * generic resource object pointed to by @res.
232  */
233 bool acpi_dev_resource_ext_address_space(struct acpi_resource *ares,
234                                          struct resource *res)
235 {
236         struct acpi_resource_extended_address64 *ext_addr;
237         bool window;
238         u64 len;
239         u8 io_decode;
240
241         if (ares->type != ACPI_RESOURCE_TYPE_EXTENDED_ADDRESS64)
242                 return false;
243
244         ext_addr = &ares->data.ext_address64;
245
246         res->start = ext_addr->minimum;
247         res->end = ext_addr->maximum;
248         window = ext_addr->producer_consumer == ACPI_PRODUCER;
249
250         switch(ext_addr->resource_type) {
251         case ACPI_MEMORY_RANGE:
252                 len = ext_addr->maximum - ext_addr->minimum + 1;
253                 res->flags = acpi_dev_memresource_flags(len,
254                                         ext_addr->info.mem.write_protect,
255                                         window);
256                 break;
257         case ACPI_IO_RANGE:
258                 io_decode = ext_addr->granularity == 0xfff ?
259                                 ACPI_DECODE_10 : ACPI_DECODE_16;
260                 res->flags = acpi_dev_ioresource_flags(ext_addr->minimum,
261                                                        ext_addr->maximum,
262                                                        io_decode, window);
263                 break;
264         case ACPI_BUS_NUMBER_RANGE:
265                 res->flags = IORESOURCE_BUS;
266                 break;
267         default:
268                 res->flags = 0;
269         }
270
271         return true;
272 }
273 EXPORT_SYMBOL_GPL(acpi_dev_resource_ext_address_space);
274
275 /**
276  * acpi_dev_irq_flags - Determine IRQ resource flags.
277  * @triggering: Triggering type as provided by ACPI.
278  * @polarity: Interrupt polarity as provided by ACPI.
279  * @shareable: Whether or not the interrupt is shareable.
280  */
281 unsigned long acpi_dev_irq_flags(u8 triggering, u8 polarity, u8 shareable)
282 {
283         unsigned long flags;
284
285         if (triggering == ACPI_LEVEL_SENSITIVE)
286                 flags = polarity == ACPI_ACTIVE_LOW ?
287                         IORESOURCE_IRQ_LOWLEVEL : IORESOURCE_IRQ_HIGHLEVEL;
288         else
289                 flags = polarity == ACPI_ACTIVE_LOW ?
290                         IORESOURCE_IRQ_LOWEDGE : IORESOURCE_IRQ_HIGHEDGE;
291
292         if (shareable == ACPI_SHARED)
293                 flags |= IORESOURCE_IRQ_SHAREABLE;
294
295         return flags | IORESOURCE_IRQ;
296 }
297 EXPORT_SYMBOL_GPL(acpi_dev_irq_flags);
298
299 static void acpi_dev_irqresource_disabled(struct resource *res, u32 gsi)
300 {
301         res->start = gsi;
302         res->end = gsi;
303         res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED;
304 }
305
306 static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
307                                      u8 triggering, u8 polarity, u8 shareable)
308 {
309         int irq, p, t;
310
311         if (!valid_IRQ(gsi)) {
312                 acpi_dev_irqresource_disabled(res, gsi);
313                 return;
314         }
315
316         /*
317          * In IO-APIC mode, use overrided attribute. Two reasons:
318          * 1. BIOS bug in DSDT
319          * 2. BIOS uses IO-APIC mode Interrupt Source Override
320          */
321         if (!acpi_get_override_irq(gsi, &t, &p)) {
322                 u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
323                 u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
324
325                 if (triggering != trig || polarity != pol) {
326                         pr_warning("ACPI: IRQ %d override to %s, %s\n", gsi,
327                                    t ? "edge" : "level", p ? "low" : "high");
328                         triggering = trig;
329                         polarity = pol;
330                 }
331         }
332
333         res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
334         irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
335         if (irq >= 0) {
336                 res->start = irq;
337                 res->end = irq;
338         } else {
339                 acpi_dev_irqresource_disabled(res, gsi);
340         }
341 }
342
343 /**
344  * acpi_dev_resource_interrupt - Extract ACPI interrupt resource information.
345  * @ares: Input ACPI resource object.
346  * @index: Index into the array of GSIs represented by the resource.
347  * @res: Output generic resource object.
348  *
349  * Check if the given ACPI resource object represents an interrupt resource
350  * and @index does not exceed the resource's interrupt count (true is returned
351  * in that case regardless of the results of the other checks)).  If that's the
352  * case, register the GSI corresponding to @index from the array of interrupts
353  * represented by the resource and populate the generic resource object pointed
354  * to by @res accordingly.  If the registration of the GSI is not successful,
355  * IORESOURCE_DISABLED will be set it that object's flags.
356  */
357 bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
358                                  struct resource *res)
359 {
360         struct acpi_resource_irq *irq;
361         struct acpi_resource_extended_irq *ext_irq;
362
363         switch (ares->type) {
364         case ACPI_RESOURCE_TYPE_IRQ:
365                 /*
366                  * Per spec, only one interrupt per descriptor is allowed in
367                  * _CRS, but some firmware violates this, so parse them all.
368                  */
369                 irq = &ares->data.irq;
370                 if (index >= irq->interrupt_count) {
371                         acpi_dev_irqresource_disabled(res, 0);
372                         return false;
373                 }
374                 acpi_dev_get_irqresource(res, irq->interrupts[index],
375                                          irq->triggering, irq->polarity,
376                                          irq->sharable);
377                 break;
378         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
379                 ext_irq = &ares->data.extended_irq;
380                 if (index >= ext_irq->interrupt_count) {
381                         acpi_dev_irqresource_disabled(res, 0);
382                         return false;
383                 }
384                 acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
385                                          ext_irq->triggering, ext_irq->polarity,
386                                          ext_irq->sharable);
387                 break;
388         default:
389                 return false;
390         }
391
392         return true;
393 }
394 EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt);
395
396 /**
397  * acpi_dev_free_resource_list - Free resource from %acpi_dev_get_resources().
398  * @list: The head of the resource list to free.
399  */
400 void acpi_dev_free_resource_list(struct list_head *list)
401 {
402         struct resource_list_entry *rentry, *re;
403
404         list_for_each_entry_safe(rentry, re, list, node) {
405                 list_del(&rentry->node);
406                 kfree(rentry);
407         }
408 }
409 EXPORT_SYMBOL_GPL(acpi_dev_free_resource_list);
410
411 struct res_proc_context {
412         struct list_head *list;
413         int (*preproc)(struct acpi_resource *, void *);
414         void *preproc_data;
415         int count;
416         int error;
417 };
418
419 static acpi_status acpi_dev_new_resource_entry(struct resource *r,
420                                                struct res_proc_context *c)
421 {
422         struct resource_list_entry *rentry;
423
424         rentry = kmalloc(sizeof(*rentry), GFP_KERNEL);
425         if (!rentry) {
426                 c->error = -ENOMEM;
427                 return AE_NO_MEMORY;
428         }
429         rentry->res = *r;
430         list_add_tail(&rentry->node, c->list);
431         c->count++;
432         return AE_OK;
433 }
434
435 static acpi_status acpi_dev_process_resource(struct acpi_resource *ares,
436                                              void *context)
437 {
438         struct res_proc_context *c = context;
439         struct resource r;
440         int i;
441
442         if (c->preproc) {
443                 int ret;
444
445                 ret = c->preproc(ares, c->preproc_data);
446                 if (ret < 0) {
447                         c->error = ret;
448                         return AE_CTRL_TERMINATE;
449                 } else if (ret > 0) {
450                         return AE_OK;
451                 }
452         }
453
454         memset(&r, 0, sizeof(r));
455
456         if (acpi_dev_resource_memory(ares, &r)
457             || acpi_dev_resource_io(ares, &r)
458             || acpi_dev_resource_address_space(ares, &r)
459             || acpi_dev_resource_ext_address_space(ares, &r))
460                 return acpi_dev_new_resource_entry(&r, c);
461
462         for (i = 0; acpi_dev_resource_interrupt(ares, i, &r); i++) {
463                 acpi_status status;
464
465                 status = acpi_dev_new_resource_entry(&r, c);
466                 if (ACPI_FAILURE(status))
467                         return status;
468         }
469
470         return AE_OK;
471 }
472
473 /**
474  * acpi_dev_get_resources - Get current resources of a device.
475  * @adev: ACPI device node to get the resources for.
476  * @list: Head of the resultant list of resources (must be empty).
477  * @preproc: The caller's preprocessing routine.
478  * @preproc_data: Pointer passed to the caller's preprocessing routine.
479  *
480  * Evaluate the _CRS method for the given device node and process its output by
481  * (1) executing the @preproc() rountine provided by the caller, passing the
482  * resource pointer and @preproc_data to it as arguments, for each ACPI resource
483  * returned and (2) converting all of the returned ACPI resources into struct
484  * resource objects if possible.  If the return value of @preproc() in step (1)
485  * is different from 0, step (2) is not applied to the given ACPI resource and
486  * if that value is negative, the whole processing is aborted and that value is
487  * returned as the final error code.
488  *
489  * The resultant struct resource objects are put on the list pointed to by
490  * @list, that must be empty initially, as members of struct resource_list_entry
491  * objects.  Callers of this routine should use %acpi_dev_free_resource_list() to
492  * free that list.
493  *
494  * The number of resources in the output list is returned on success, an error
495  * code reflecting the error condition is returned otherwise.
496  */
497 int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
498                            int (*preproc)(struct acpi_resource *, void *),
499                            void *preproc_data)
500 {
501         struct res_proc_context c;
502         acpi_handle not_used;
503         acpi_status status;
504
505         if (!adev || !adev->handle || !list_empty(list))
506                 return -EINVAL;
507
508         status = acpi_get_handle(adev->handle, METHOD_NAME__CRS, &not_used);
509         if (ACPI_FAILURE(status))
510                 return 0;
511
512         c.list = list;
513         c.preproc = preproc;
514         c.preproc_data = preproc_data;
515         c.count = 0;
516         c.error = 0;
517         status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
518                                      acpi_dev_process_resource, &c);
519         if (ACPI_FAILURE(status)) {
520                 acpi_dev_free_resource_list(list);
521                 return c.error ? c.error : -EIO;
522         }
523
524         return c.count;
525 }
526 EXPORT_SYMBOL_GPL(acpi_dev_get_resources);