xref: /openbmc/qemu/hw/acpi/core.c (revision bfb27e60)
1 /*
2  * ACPI implementation
3  *
4  * Copyright (c) 2006 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License version 2 as published by the Free Software Foundation.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, see <http://www.gnu.org/licenses/>
17  *
18  * Contributions after 2012-01-13 are licensed under the terms of the
19  * GNU GPL, version 2 or (at your option) any later version.
20  */
21 #include "sysemu/sysemu.h"
22 #include "hw/hw.h"
23 #include "hw/i386/pc.h"
24 #include "hw/acpi/acpi.h"
25 #include "qemu/config-file.h"
26 #include "qapi/opts-visitor.h"
27 #include "qapi/dealloc-visitor.h"
28 #include "qapi-visit.h"
29 #include "qapi-event.h"
30 
31 struct acpi_table_header {
32     uint16_t _length;         /* our length, not actual part of the hdr */
33                               /* allows easier parsing for fw_cfg clients */
34     char sig[4];              /* ACPI signature (4 ASCII characters) */
35     uint32_t length;          /* Length of table, in bytes, including header */
36     uint8_t revision;         /* ACPI Specification minor version # */
37     uint8_t checksum;         /* To make sum of entire table == 0 */
38     char oem_id[6];           /* OEM identification */
39     char oem_table_id[8];     /* OEM table identification */
40     uint32_t oem_revision;    /* OEM revision number */
41     char asl_compiler_id[4];  /* ASL compiler vendor ID */
42     uint32_t asl_compiler_revision; /* ASL compiler revision number */
43 } QEMU_PACKED;
44 
45 #define ACPI_TABLE_HDR_SIZE sizeof(struct acpi_table_header)
46 #define ACPI_TABLE_PFX_SIZE sizeof(uint16_t)  /* size of the extra prefix */
47 
48 static const char unsigned dfl_hdr[ACPI_TABLE_HDR_SIZE - ACPI_TABLE_PFX_SIZE] =
49     "QEMU\0\0\0\0\1\0"       /* sig (4), len(4), revno (1), csum (1) */
50     "QEMUQEQEMUQEMU\1\0\0\0" /* OEM id (6), table (8), revno (4) */
51     "QEMU\1\0\0\0"           /* ASL compiler ID (4), version (4) */
52     ;
53 
54 char unsigned *acpi_tables;
55 size_t acpi_tables_len;
56 
57 static QemuOptsList qemu_acpi_opts = {
58     .name = "acpi",
59     .implied_opt_name = "data",
60     .head = QTAILQ_HEAD_INITIALIZER(qemu_acpi_opts.head),
61     .desc = { { 0 } } /* validated with OptsVisitor */
62 };
63 
64 static void acpi_register_config(void)
65 {
66     qemu_add_opts(&qemu_acpi_opts);
67 }
68 
69 machine_init(acpi_register_config);
70 
71 static int acpi_checksum(const uint8_t *data, int len)
72 {
73     int sum, i;
74     sum = 0;
75     for (i = 0; i < len; i++) {
76         sum += data[i];
77     }
78     return (-sum) & 0xff;
79 }
80 
81 
82 /* Install a copy of the ACPI table specified in @blob.
83  *
84  * If @has_header is set, @blob starts with the System Description Table Header
85  * structure. Otherwise, "dfl_hdr" is prepended. In any case, each header field
86  * is optionally overwritten from @hdrs.
87  *
88  * It is valid to call this function with
89  * (@blob == NULL && bloblen == 0 && !has_header).
90  *
91  * @hdrs->file and @hdrs->data are ignored.
92  *
93  * SIZE_MAX is considered "infinity" in this function.
94  *
95  * The number of tables that can be installed is not limited, but the 16-bit
96  * counter at the beginning of "acpi_tables" wraps around after UINT16_MAX.
97  */
98 static void acpi_table_install(const char unsigned *blob, size_t bloblen,
99                                bool has_header,
100                                const struct AcpiTableOptions *hdrs,
101                                Error **errp)
102 {
103     size_t body_start;
104     const char unsigned *hdr_src;
105     size_t body_size, acpi_payload_size;
106     struct acpi_table_header *ext_hdr;
107     unsigned changed_fields;
108 
109     /* Calculate where the ACPI table body starts within the blob, plus where
110      * to copy the ACPI table header from.
111      */
112     if (has_header) {
113         /*   _length             | ACPI header in blob | blob body
114          *   ^^^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^^^   ^^^^^^^^^
115          *   ACPI_TABLE_PFX_SIZE     sizeof dfl_hdr      body_size
116          *                           == body_start
117          *
118          *                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
119          *                           acpi_payload_size == bloblen
120          */
121         body_start = sizeof dfl_hdr;
122 
123         if (bloblen < body_start) {
124             error_setg(errp, "ACPI table claiming to have header is too "
125                        "short, available: %zu, expected: %zu", bloblen,
126                        body_start);
127             return;
128         }
129         hdr_src = blob;
130     } else {
131         /*   _length             | ACPI header in template | blob body
132          *   ^^^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^^^^^^^   ^^^^^^^^^^
133          *   ACPI_TABLE_PFX_SIZE       sizeof dfl_hdr        body_size
134          *                                                   == bloblen
135          *
136          *                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
137          *                                  acpi_payload_size
138          */
139         body_start = 0;
140         hdr_src = dfl_hdr;
141     }
142     body_size = bloblen - body_start;
143     acpi_payload_size = sizeof dfl_hdr + body_size;
144 
145     if (acpi_payload_size > UINT16_MAX) {
146         error_setg(errp, "ACPI table too big, requested: %zu, max: %u",
147                    acpi_payload_size, (unsigned)UINT16_MAX);
148         return;
149     }
150 
151     /* We won't fail from here on. Initialize / extend the globals. */
152     if (acpi_tables == NULL) {
153         acpi_tables_len = sizeof(uint16_t);
154         acpi_tables = g_malloc0(acpi_tables_len);
155     }
156 
157     acpi_tables = g_realloc(acpi_tables, acpi_tables_len +
158                                          ACPI_TABLE_PFX_SIZE +
159                                          sizeof dfl_hdr + body_size);
160 
161     ext_hdr = (struct acpi_table_header *)(acpi_tables + acpi_tables_len);
162     acpi_tables_len += ACPI_TABLE_PFX_SIZE;
163 
164     memcpy(acpi_tables + acpi_tables_len, hdr_src, sizeof dfl_hdr);
165     acpi_tables_len += sizeof dfl_hdr;
166 
167     if (blob != NULL) {
168         memcpy(acpi_tables + acpi_tables_len, blob + body_start, body_size);
169         acpi_tables_len += body_size;
170     }
171 
172     /* increase number of tables */
173     stw_le_p(acpi_tables, lduw_le_p(acpi_tables) + 1u);
174 
175     /* Update the header fields. The strings need not be NUL-terminated. */
176     changed_fields = 0;
177     ext_hdr->_length = cpu_to_le16(acpi_payload_size);
178 
179     if (hdrs->has_sig) {
180         strncpy(ext_hdr->sig, hdrs->sig, sizeof ext_hdr->sig);
181         ++changed_fields;
182     }
183 
184     if (has_header && le32_to_cpu(ext_hdr->length) != acpi_payload_size) {
185         fprintf(stderr,
186                 "warning: ACPI table has wrong length, header says "
187                 "%" PRIu32 ", actual size %zu bytes\n",
188                 le32_to_cpu(ext_hdr->length), acpi_payload_size);
189     }
190     ext_hdr->length = cpu_to_le32(acpi_payload_size);
191 
192     if (hdrs->has_rev) {
193         ext_hdr->revision = hdrs->rev;
194         ++changed_fields;
195     }
196 
197     ext_hdr->checksum = 0;
198 
199     if (hdrs->has_oem_id) {
200         strncpy(ext_hdr->oem_id, hdrs->oem_id, sizeof ext_hdr->oem_id);
201         ++changed_fields;
202     }
203     if (hdrs->has_oem_table_id) {
204         strncpy(ext_hdr->oem_table_id, hdrs->oem_table_id,
205                 sizeof ext_hdr->oem_table_id);
206         ++changed_fields;
207     }
208     if (hdrs->has_oem_rev) {
209         ext_hdr->oem_revision = cpu_to_le32(hdrs->oem_rev);
210         ++changed_fields;
211     }
212     if (hdrs->has_asl_compiler_id) {
213         strncpy(ext_hdr->asl_compiler_id, hdrs->asl_compiler_id,
214                 sizeof ext_hdr->asl_compiler_id);
215         ++changed_fields;
216     }
217     if (hdrs->has_asl_compiler_rev) {
218         ext_hdr->asl_compiler_revision = cpu_to_le32(hdrs->asl_compiler_rev);
219         ++changed_fields;
220     }
221 
222     if (!has_header && changed_fields == 0) {
223         fprintf(stderr, "warning: ACPI table: no headers are specified\n");
224     }
225 
226     /* recalculate checksum */
227     ext_hdr->checksum = acpi_checksum((const char unsigned *)ext_hdr +
228                                       ACPI_TABLE_PFX_SIZE, acpi_payload_size);
229 }
230 
231 void acpi_table_add(const QemuOpts *opts, Error **errp)
232 {
233     AcpiTableOptions *hdrs = NULL;
234     Error *err = NULL;
235     char **pathnames = NULL;
236     char **cur;
237     size_t bloblen = 0;
238     char unsigned *blob = NULL;
239 
240     {
241         OptsVisitor *ov;
242 
243         ov = opts_visitor_new(opts);
244         visit_type_AcpiTableOptions(opts_get_visitor(ov), &hdrs, NULL, &err);
245         opts_visitor_cleanup(ov);
246     }
247 
248     if (err) {
249         goto out;
250     }
251     if (hdrs->has_file == hdrs->has_data) {
252         error_setg(&err, "'-acpitable' requires one of 'data' or 'file'");
253         goto out;
254     }
255 
256     pathnames = g_strsplit(hdrs->has_file ? hdrs->file : hdrs->data, ":", 0);
257     if (pathnames == NULL || pathnames[0] == NULL) {
258         error_setg(&err, "'-acpitable' requires at least one pathname");
259         goto out;
260     }
261 
262     /* now read in the data files, reallocating buffer as needed */
263     for (cur = pathnames; *cur; ++cur) {
264         int fd = open(*cur, O_RDONLY | O_BINARY);
265 
266         if (fd < 0) {
267             error_setg(&err, "can't open file %s: %s", *cur, strerror(errno));
268             goto out;
269         }
270 
271         for (;;) {
272             char unsigned data[8192];
273             ssize_t r;
274 
275             r = read(fd, data, sizeof data);
276             if (r == 0) {
277                 break;
278             } else if (r > 0) {
279                 blob = g_realloc(blob, bloblen + r);
280                 memcpy(blob + bloblen, data, r);
281                 bloblen += r;
282             } else if (errno != EINTR) {
283                 error_setg(&err, "can't read file %s: %s",
284                            *cur, strerror(errno));
285                 close(fd);
286                 goto out;
287             }
288         }
289 
290         close(fd);
291     }
292 
293     acpi_table_install(blob, bloblen, hdrs->has_file, hdrs, &err);
294 
295 out:
296     g_free(blob);
297     g_strfreev(pathnames);
298 
299     if (hdrs != NULL) {
300         QapiDeallocVisitor *dv;
301 
302         dv = qapi_dealloc_visitor_new();
303         visit_type_AcpiTableOptions(qapi_dealloc_get_visitor(dv), &hdrs, NULL,
304                                     NULL);
305         qapi_dealloc_visitor_cleanup(dv);
306     }
307 
308     error_propagate(errp, err);
309 }
310 
311 static bool acpi_table_builtin = false;
312 
313 void acpi_table_add_builtin(const QemuOpts *opts, Error **errp)
314 {
315     acpi_table_builtin = true;
316     acpi_table_add(opts, errp);
317 }
318 
319 unsigned acpi_table_len(void *current)
320 {
321     struct acpi_table_header *hdr = current - sizeof(hdr->_length);
322     return hdr->_length;
323 }
324 
325 static
326 void *acpi_table_hdr(void *h)
327 {
328     struct acpi_table_header *hdr = h;
329     return &hdr->sig;
330 }
331 
332 uint8_t *acpi_table_first(void)
333 {
334     if (acpi_table_builtin || !acpi_tables) {
335         return NULL;
336     }
337     return acpi_table_hdr(acpi_tables + ACPI_TABLE_PFX_SIZE);
338 }
339 
340 uint8_t *acpi_table_next(uint8_t *current)
341 {
342     uint8_t *next = current + acpi_table_len(current);
343 
344     if (next - acpi_tables >= acpi_tables_len) {
345         return NULL;
346     } else {
347         return acpi_table_hdr(next);
348     }
349 }
350 
351 static void acpi_notify_wakeup(Notifier *notifier, void *data)
352 {
353     ACPIREGS *ar = container_of(notifier, ACPIREGS, wakeup);
354     WakeupReason *reason = data;
355 
356     switch (*reason) {
357     case QEMU_WAKEUP_REASON_RTC:
358         ar->pm1.evt.sts |=
359             (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_RT_CLOCK_STATUS);
360         break;
361     case QEMU_WAKEUP_REASON_PMTIMER:
362         ar->pm1.evt.sts |=
363             (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_TIMER_STATUS);
364         break;
365     case QEMU_WAKEUP_REASON_OTHER:
366         /* ACPI_BITMASK_WAKE_STATUS should be set on resume.
367            Pretend that resume was caused by power button */
368         ar->pm1.evt.sts |=
369             (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_POWER_BUTTON_STATUS);
370         break;
371     default:
372         break;
373     }
374 }
375 
376 /* ACPI PM1a EVT */
377 uint16_t acpi_pm1_evt_get_sts(ACPIREGS *ar)
378 {
379     int64_t d = acpi_pm_tmr_get_clock();
380     if (d >= ar->tmr.overflow_time) {
381         ar->pm1.evt.sts |= ACPI_BITMASK_TIMER_STATUS;
382     }
383     return ar->pm1.evt.sts;
384 }
385 
386 static void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val)
387 {
388     uint16_t pm1_sts = acpi_pm1_evt_get_sts(ar);
389     if (pm1_sts & val & ACPI_BITMASK_TIMER_STATUS) {
390         /* if TMRSTS is reset, then compute the new overflow time */
391         acpi_pm_tmr_calc_overflow_time(ar);
392     }
393     ar->pm1.evt.sts &= ~val;
394 }
395 
396 static void acpi_pm1_evt_write_en(ACPIREGS *ar, uint16_t val)
397 {
398     ar->pm1.evt.en = val;
399     qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_RTC,
400                               val & ACPI_BITMASK_RT_CLOCK_ENABLE);
401     qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_PMTIMER,
402                               val & ACPI_BITMASK_TIMER_ENABLE);
403 }
404 
405 void acpi_pm1_evt_power_down(ACPIREGS *ar)
406 {
407     if (ar->pm1.evt.en & ACPI_BITMASK_POWER_BUTTON_ENABLE) {
408         ar->pm1.evt.sts |= ACPI_BITMASK_POWER_BUTTON_STATUS;
409         ar->tmr.update_sci(ar);
410     }
411 }
412 
413 void acpi_pm1_evt_reset(ACPIREGS *ar)
414 {
415     ar->pm1.evt.sts = 0;
416     ar->pm1.evt.en = 0;
417     qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_RTC, 0);
418     qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_PMTIMER, 0);
419 }
420 
421 static uint64_t acpi_pm_evt_read(void *opaque, hwaddr addr, unsigned width)
422 {
423     ACPIREGS *ar = opaque;
424     switch (addr) {
425     case 0:
426         return acpi_pm1_evt_get_sts(ar);
427     case 2:
428         return ar->pm1.evt.en;
429     default:
430         return 0;
431     }
432 }
433 
434 static void acpi_pm_evt_write(void *opaque, hwaddr addr, uint64_t val,
435                               unsigned width)
436 {
437     ACPIREGS *ar = opaque;
438     switch (addr) {
439     case 0:
440         acpi_pm1_evt_write_sts(ar, val);
441         ar->pm1.evt.update_sci(ar);
442         break;
443     case 2:
444         acpi_pm1_evt_write_en(ar, val);
445         ar->pm1.evt.update_sci(ar);
446         break;
447     }
448 }
449 
450 static const MemoryRegionOps acpi_pm_evt_ops = {
451     .read = acpi_pm_evt_read,
452     .write = acpi_pm_evt_write,
453     .valid.min_access_size = 2,
454     .valid.max_access_size = 2,
455     .endianness = DEVICE_LITTLE_ENDIAN,
456 };
457 
458 void acpi_pm1_evt_init(ACPIREGS *ar, acpi_update_sci_fn update_sci,
459                        MemoryRegion *parent)
460 {
461     ar->pm1.evt.update_sci = update_sci;
462     memory_region_init_io(&ar->pm1.evt.io, memory_region_owner(parent),
463                           &acpi_pm_evt_ops, ar, "acpi-evt", 4);
464     memory_region_add_subregion(parent, 0, &ar->pm1.evt.io);
465 }
466 
467 /* ACPI PM_TMR */
468 void acpi_pm_tmr_update(ACPIREGS *ar, bool enable)
469 {
470     int64_t expire_time;
471 
472     /* schedule a timer interruption if needed */
473     if (enable) {
474         expire_time = muldiv64(ar->tmr.overflow_time, get_ticks_per_sec(),
475                                PM_TIMER_FREQUENCY);
476         timer_mod(ar->tmr.timer, expire_time);
477     } else {
478         timer_del(ar->tmr.timer);
479     }
480 }
481 
482 void acpi_pm_tmr_calc_overflow_time(ACPIREGS *ar)
483 {
484     int64_t d = acpi_pm_tmr_get_clock();
485     ar->tmr.overflow_time = (d + 0x800000LL) & ~0x7fffffLL;
486 }
487 
488 static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)
489 {
490     uint32_t d = acpi_pm_tmr_get_clock();
491     return d & 0xffffff;
492 }
493 
494 static void acpi_pm_tmr_timer(void *opaque)
495 {
496     ACPIREGS *ar = opaque;
497     qemu_system_wakeup_request(QEMU_WAKEUP_REASON_PMTIMER);
498     ar->tmr.update_sci(ar);
499 }
500 
501 static uint64_t acpi_pm_tmr_read(void *opaque, hwaddr addr, unsigned width)
502 {
503     return acpi_pm_tmr_get(opaque);
504 }
505 
506 static void acpi_pm_tmr_write(void *opaque, hwaddr addr, uint64_t val,
507                               unsigned width)
508 {
509     /* nothing */
510 }
511 
512 static const MemoryRegionOps acpi_pm_tmr_ops = {
513     .read = acpi_pm_tmr_read,
514     .write = acpi_pm_tmr_write,
515     .valid.min_access_size = 4,
516     .valid.max_access_size = 4,
517     .endianness = DEVICE_LITTLE_ENDIAN,
518 };
519 
520 void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci,
521                       MemoryRegion *parent)
522 {
523     ar->tmr.update_sci = update_sci;
524     ar->tmr.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, acpi_pm_tmr_timer, ar);
525     memory_region_init_io(&ar->tmr.io, memory_region_owner(parent),
526                           &acpi_pm_tmr_ops, ar, "acpi-tmr", 4);
527     memory_region_add_subregion(parent, 8, &ar->tmr.io);
528 }
529 
530 void acpi_pm_tmr_reset(ACPIREGS *ar)
531 {
532     ar->tmr.overflow_time = 0;
533     timer_del(ar->tmr.timer);
534 }
535 
536 /* ACPI PM1aCNT */
537 static void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val)
538 {
539     ar->pm1.cnt.cnt = val & ~(ACPI_BITMASK_SLEEP_ENABLE);
540 
541     if (val & ACPI_BITMASK_SLEEP_ENABLE) {
542         /* change suspend type */
543         uint16_t sus_typ = (val >> 10) & 7;
544         switch(sus_typ) {
545         case 0: /* soft power off */
546             qemu_system_shutdown_request();
547             break;
548         case 1:
549             qemu_system_suspend_request();
550             break;
551         default:
552             if (sus_typ == ar->pm1.cnt.s4_val) { /* S4 request */
553                 qapi_event_send_suspend_disk(&error_abort);
554                 qemu_system_shutdown_request();
555             }
556             break;
557         }
558     }
559 }
560 
561 void acpi_pm1_cnt_update(ACPIREGS *ar,
562                          bool sci_enable, bool sci_disable)
563 {
564     /* ACPI specs 3.0, 4.7.2.5 */
565     if (sci_enable) {
566         ar->pm1.cnt.cnt |= ACPI_BITMASK_SCI_ENABLE;
567     } else if (sci_disable) {
568         ar->pm1.cnt.cnt &= ~ACPI_BITMASK_SCI_ENABLE;
569     }
570 }
571 
572 static uint64_t acpi_pm_cnt_read(void *opaque, hwaddr addr, unsigned width)
573 {
574     ACPIREGS *ar = opaque;
575     return ar->pm1.cnt.cnt;
576 }
577 
578 static void acpi_pm_cnt_write(void *opaque, hwaddr addr, uint64_t val,
579                               unsigned width)
580 {
581     acpi_pm1_cnt_write(opaque, val);
582 }
583 
584 static const MemoryRegionOps acpi_pm_cnt_ops = {
585     .read = acpi_pm_cnt_read,
586     .write = acpi_pm_cnt_write,
587     .valid.min_access_size = 2,
588     .valid.max_access_size = 2,
589     .endianness = DEVICE_LITTLE_ENDIAN,
590 };
591 
592 void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent, uint8_t s4_val)
593 {
594     ar->pm1.cnt.s4_val = s4_val;
595     ar->wakeup.notify = acpi_notify_wakeup;
596     qemu_register_wakeup_notifier(&ar->wakeup);
597     memory_region_init_io(&ar->pm1.cnt.io, memory_region_owner(parent),
598                           &acpi_pm_cnt_ops, ar, "acpi-cnt", 2);
599     memory_region_add_subregion(parent, 4, &ar->pm1.cnt.io);
600 }
601 
602 void acpi_pm1_cnt_reset(ACPIREGS *ar)
603 {
604     ar->pm1.cnt.cnt = 0;
605 }
606 
607 /* ACPI GPE */
608 void acpi_gpe_init(ACPIREGS *ar, uint8_t len)
609 {
610     ar->gpe.len = len;
611     ar->gpe.sts = g_malloc0(len / 2);
612     ar->gpe.en = g_malloc0(len / 2);
613 }
614 
615 void acpi_gpe_reset(ACPIREGS *ar)
616 {
617     memset(ar->gpe.sts, 0, ar->gpe.len / 2);
618     memset(ar->gpe.en, 0, ar->gpe.len / 2);
619 }
620 
621 static uint8_t *acpi_gpe_ioport_get_ptr(ACPIREGS *ar, uint32_t addr)
622 {
623     uint8_t *cur = NULL;
624 
625     if (addr < ar->gpe.len / 2) {
626         cur = ar->gpe.sts + addr;
627     } else if (addr < ar->gpe.len) {
628         cur = ar->gpe.en + addr - ar->gpe.len / 2;
629     } else {
630         abort();
631     }
632 
633     return cur;
634 }
635 
636 void acpi_gpe_ioport_writeb(ACPIREGS *ar, uint32_t addr, uint32_t val)
637 {
638     uint8_t *cur;
639 
640     cur = acpi_gpe_ioport_get_ptr(ar, addr);
641     if (addr < ar->gpe.len / 2) {
642         /* GPE_STS */
643         *cur = (*cur) & ~val;
644     } else if (addr < ar->gpe.len) {
645         /* GPE_EN */
646         *cur = val;
647     } else {
648         abort();
649     }
650 }
651 
652 uint32_t acpi_gpe_ioport_readb(ACPIREGS *ar, uint32_t addr)
653 {
654     uint8_t *cur;
655     uint32_t val;
656 
657     cur = acpi_gpe_ioport_get_ptr(ar, addr);
658     val = 0;
659     if (cur != NULL) {
660         val = *cur;
661     }
662 
663     return val;
664 }
665 
666 void acpi_update_sci(ACPIREGS *regs, qemu_irq irq)
667 {
668     int sci_level, pm1a_sts;
669 
670     pm1a_sts = acpi_pm1_evt_get_sts(regs);
671 
672     sci_level = ((pm1a_sts &
673                   regs->pm1.evt.en & ACPI_BITMASK_PM1_COMMON_ENABLED) != 0) ||
674                 ((regs->gpe.sts[0] & regs->gpe.en[0]) != 0);
675 
676     qemu_set_irq(irq, sci_level);
677 
678     /* schedule a timer interruption if needed */
679     acpi_pm_tmr_update(regs,
680                        (regs->pm1.evt.en & ACPI_BITMASK_TIMER_ENABLE) &&
681                        !(pm1a_sts & ACPI_BITMASK_TIMER_STATUS));
682 }
683