xref: /qemu/hw/tpm/tpm_tis_common.c (revision e92b63ea610201bd743343fc6b11e6c39c8d3515)
1 /*
2  * tpm_tis.c - QEMU's TPM TIS interface emulator
3  *
4  * Copyright (C) 2006,2010-2013 IBM Corporation
5  *
6  * Authors:
7  *  Stefan Berger <stefanb@us.ibm.com>
8  *  David Safford <safford@us.ibm.com>
9  *
10  * Xen 4 support: Andrease Niederl <andreas.niederl@iaik.tugraz.at>
11  *
12  * This work is licensed under the terms of the GNU GPL, version 2 or later.
13  * See the COPYING file in the top-level directory.
14  *
15  * Implementation of the TIS interface according to specs found at
16  * http://www.trustedcomputinggroup.org. This implementation currently
17  * supports version 1.3, 21 March 2013
18  * In the developers menu choose the PC Client section then find the TIS
19  * specification.
20  *
21  * TPM TIS for TPM 2 implementation following TCG PC Client Platform
22  * TPM Profile (PTP) Specification, Familiy 2.0, Revision 00.43
23  */
24 
25 #include "qemu/osdep.h"
26 #include "hw/isa/isa.h"
27 #include "qapi/error.h"
28 
29 #include "hw/acpi/tpm.h"
30 #include "hw/pci/pci_ids.h"
31 #include "sysemu/tpm_backend.h"
32 #include "tpm_int.h"
33 #include "tpm_util.h"
34 #include "trace.h"
35 
36 #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
37 #define TPM_TIS_LOCALITY_SHIFT      12
38 #define TPM_TIS_NO_LOCALITY         0xff
39 
40 #define TPM_TIS_IS_VALID_LOCTY(x)   ((x) < TPM_TIS_NUM_LOCALITIES)
41 
42 #define TPM_TIS_BUFFER_MAX          4096
43 
44 typedef enum {
45     TPM_TIS_STATE_IDLE = 0,
46     TPM_TIS_STATE_READY,
47     TPM_TIS_STATE_COMPLETION,
48     TPM_TIS_STATE_EXECUTION,
49     TPM_TIS_STATE_RECEPTION,
50 } TPMTISState;
51 
52 /* locality data  -- all fields are persisted */
53 typedef struct TPMLocality {
54     TPMTISState state;
55     uint8_t access;
56     uint32_t sts;
57     uint32_t iface_id;
58     uint32_t inte;
59     uint32_t ints;
60 } TPMLocality;
61 
62 typedef struct TPMState {
63     ISADevice busdev;
64     MemoryRegion mmio;
65 
66     unsigned char buffer[TPM_TIS_BUFFER_MAX];
67     uint16_t rw_offset;
68 
69     uint8_t active_locty;
70     uint8_t aborting_locty;
71     uint8_t next_locty;
72 
73     TPMLocality loc[TPM_TIS_NUM_LOCALITIES];
74 
75     qemu_irq irq;
76     uint32_t irq_num;
77 
78     TPMBackendCmd cmd;
79 
80     TPMBackend *be_driver;
81     TPMVersion be_tpm_version;
82 
83     size_t be_buffer_size;
84 } TPMState;
85 
86 #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS)
87 
88 #define DEBUG_TIS 0
89 
90 /* local prototypes */
91 
92 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
93                                   unsigned size);
94 
95 /* utility functions */
96 
97 static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
98 {
99     return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
100 }
101 
102 static void tpm_tis_show_buffer(const unsigned char *buffer,
103                                 size_t buffer_size, const char *string)
104 {
105     uint32_t len, i;
106 
107     len = MIN(tpm_cmd_get_size(buffer), buffer_size);
108     printf("tpm_tis: %s length = %d\n", string, len);
109     for (i = 0; i < len; i++) {
110         if (i && !(i % 16)) {
111             printf("\n");
112         }
113         printf("%.2X ", buffer[i]);
114     }
115     printf("\n");
116 }
117 
118 /*
119  * Set the given flags in the STS register by clearing the register but
120  * preserving the SELFTEST_DONE and TPM_FAMILY_MASK flags and then setting
121  * the new flags.
122  *
123  * The SELFTEST_DONE flag is acquired from the backend that determines it by
124  * peeking into TPM commands.
125  *
126  * A VM suspend/resume will preserve the flag by storing it into the VM
127  * device state, but the backend will not remember it when QEMU is started
128  * again. Therefore, we cache the flag here. Once set, it will not be unset
129  * except by a reset.
130  */
131 static void tpm_tis_sts_set(TPMLocality *l, uint32_t flags)
132 {
133     l->sts &= TPM_TIS_STS_SELFTEST_DONE | TPM_TIS_STS_TPM_FAMILY_MASK;
134     l->sts |= flags;
135 }
136 
137 /*
138  * Send a request to the TPM.
139  */
140 static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
141 {
142     if (DEBUG_TIS) {
143         tpm_tis_show_buffer(s->buffer, s->be_buffer_size,
144                             "tpm_tis: To TPM");
145     }
146 
147     /*
148      * rw_offset serves as length indicator for length of data;
149      * it's reset when the response comes back
150      */
151     s->loc[locty].state = TPM_TIS_STATE_EXECUTION;
152 
153     s->cmd = (TPMBackendCmd) {
154         .locty = locty,
155         .in = s->buffer,
156         .in_len = s->rw_offset,
157         .out = s->buffer,
158         .out_len = s->be_buffer_size,
159     };
160 
161     tpm_backend_deliver_request(s->be_driver, &s->cmd);
162 }
163 
164 /* raise an interrupt if allowed */
165 static void tpm_tis_raise_irq(TPMState *s, uint8_t locty, uint32_t irqmask)
166 {
167     if (!TPM_TIS_IS_VALID_LOCTY(locty)) {
168         return;
169     }
170 
171     if ((s->loc[locty].inte & TPM_TIS_INT_ENABLED) &&
172         (s->loc[locty].inte & irqmask)) {
173         trace_tpm_tis_raise_irq(irqmask);
174         qemu_irq_raise(s->irq);
175         s->loc[locty].ints |= irqmask;
176     }
177 }
178 
179 static uint32_t tpm_tis_check_request_use_except(TPMState *s, uint8_t locty)
180 {
181     uint8_t l;
182 
183     for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
184         if (l == locty) {
185             continue;
186         }
187         if ((s->loc[l].access & TPM_TIS_ACCESS_REQUEST_USE)) {
188             return 1;
189         }
190     }
191 
192     return 0;
193 }
194 
195 static void tpm_tis_new_active_locality(TPMState *s, uint8_t new_active_locty)
196 {
197     bool change = (s->active_locty != new_active_locty);
198     bool is_seize;
199     uint8_t mask;
200 
201     if (change && TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
202         is_seize = TPM_TIS_IS_VALID_LOCTY(new_active_locty) &&
203                    s->loc[new_active_locty].access & TPM_TIS_ACCESS_SEIZE;
204 
205         if (is_seize) {
206             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY);
207         } else {
208             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY|
209                      TPM_TIS_ACCESS_REQUEST_USE);
210         }
211         /* reset flags on the old active locality */
212         s->loc[s->active_locty].access &= mask;
213 
214         if (is_seize) {
215             s->loc[s->active_locty].access |= TPM_TIS_ACCESS_BEEN_SEIZED;
216         }
217     }
218 
219     s->active_locty = new_active_locty;
220 
221     trace_tpm_tis_new_active_locality(s->active_locty);
222 
223     if (TPM_TIS_IS_VALID_LOCTY(new_active_locty)) {
224         /* set flags on the new active locality */
225         s->loc[new_active_locty].access |= TPM_TIS_ACCESS_ACTIVE_LOCALITY;
226         s->loc[new_active_locty].access &= ~(TPM_TIS_ACCESS_REQUEST_USE |
227                                                TPM_TIS_ACCESS_SEIZE);
228     }
229 
230     if (change) {
231         tpm_tis_raise_irq(s, s->active_locty, TPM_TIS_INT_LOCALITY_CHANGED);
232     }
233 }
234 
235 /* abort -- this function switches the locality */
236 static void tpm_tis_abort(TPMState *s)
237 {
238     s->rw_offset = 0;
239 
240     trace_tpm_tis_abort(s->next_locty);
241 
242     /*
243      * Need to react differently depending on who's aborting now and
244      * which locality will become active afterwards.
245      */
246     if (s->aborting_locty == s->next_locty) {
247         s->loc[s->aborting_locty].state = TPM_TIS_STATE_READY;
248         tpm_tis_sts_set(&s->loc[s->aborting_locty],
249                         TPM_TIS_STS_COMMAND_READY);
250         tpm_tis_raise_irq(s, s->aborting_locty, TPM_TIS_INT_COMMAND_READY);
251     }
252 
253     /* locality after abort is another one than the current one */
254     tpm_tis_new_active_locality(s, s->next_locty);
255 
256     s->next_locty = TPM_TIS_NO_LOCALITY;
257     /* nobody's aborting a command anymore */
258     s->aborting_locty = TPM_TIS_NO_LOCALITY;
259 }
260 
261 /* prepare aborting current command */
262 static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
263 {
264     uint8_t busy_locty;
265 
266     assert(TPM_TIS_IS_VALID_LOCTY(newlocty));
267 
268     s->aborting_locty = locty; /* may also be TPM_TIS_NO_LOCALITY */
269     s->next_locty = newlocty;  /* locality after successful abort */
270 
271     /*
272      * only abort a command using an interrupt if currently executing
273      * a command AND if there's a valid connection to the vTPM.
274      */
275     for (busy_locty = 0; busy_locty < TPM_TIS_NUM_LOCALITIES; busy_locty++) {
276         if (s->loc[busy_locty].state == TPM_TIS_STATE_EXECUTION) {
277             /*
278              * request the backend to cancel. Some backends may not
279              * support it
280              */
281             tpm_backend_cancel_cmd(s->be_driver);
282             return;
283         }
284     }
285 
286     tpm_tis_abort(s);
287 }
288 
289 /*
290  * Callback from the TPM to indicate that the response was received.
291  */
292 static void tpm_tis_request_completed(TPMIf *ti, int ret)
293 {
294     TPMState *s = TPM(ti);
295     uint8_t locty = s->cmd.locty;
296     uint8_t l;
297 
298     if (s->cmd.selftest_done) {
299         for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
300             s->loc[l].sts |= TPM_TIS_STS_SELFTEST_DONE;
301         }
302     }
303 
304     /* FIXME: report error if ret != 0 */
305     tpm_tis_sts_set(&s->loc[locty],
306                     TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
307     s->loc[locty].state = TPM_TIS_STATE_COMPLETION;
308     s->rw_offset = 0;
309 
310     if (DEBUG_TIS) {
311         tpm_tis_show_buffer(s->buffer, s->be_buffer_size,
312                             "tpm_tis: From TPM");
313     }
314 
315     if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
316         tpm_tis_abort(s);
317     }
318 
319     tpm_tis_raise_irq(s, locty,
320                       TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
321 }
322 
323 /*
324  * Read a byte of response data
325  */
326 static uint32_t tpm_tis_data_read(TPMState *s, uint8_t locty)
327 {
328     uint32_t ret = TPM_TIS_NO_DATA_BYTE;
329     uint16_t len;
330 
331     if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
332         len = MIN(tpm_cmd_get_size(&s->buffer),
333                   s->be_buffer_size);
334 
335         ret = s->buffer[s->rw_offset++];
336         if (s->rw_offset >= len) {
337             /* got last byte */
338             tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
339             tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
340         }
341         trace_tpm_tis_data_read(ret, s->rw_offset - 1);
342     }
343 
344     return ret;
345 }
346 
347 #ifdef DEBUG_TIS
348 static void tpm_tis_dump_state(void *opaque, hwaddr addr)
349 {
350     static const unsigned regs[] = {
351         TPM_TIS_REG_ACCESS,
352         TPM_TIS_REG_INT_ENABLE,
353         TPM_TIS_REG_INT_VECTOR,
354         TPM_TIS_REG_INT_STATUS,
355         TPM_TIS_REG_INTF_CAPABILITY,
356         TPM_TIS_REG_STS,
357         TPM_TIS_REG_DID_VID,
358         TPM_TIS_REG_RID,
359         0xfff};
360     int idx;
361     uint8_t locty = tpm_tis_locality_from_addr(addr);
362     hwaddr base = addr & ~0xfff;
363     TPMState *s = opaque;
364 
365     printf("tpm_tis: active locality      : %d\n"
366            "tpm_tis: state of locality %d : %d\n"
367            "tpm_tis: register dump:\n",
368            s->active_locty,
369            locty, s->loc[locty].state);
370 
371     for (idx = 0; regs[idx] != 0xfff; idx++) {
372         printf("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
373                (int)tpm_tis_mmio_read(opaque, base + regs[idx], 4));
374     }
375 
376     printf("tpm_tis: r/w offset    : %d\n"
377            "tpm_tis: result buffer : ",
378            s->rw_offset);
379     for (idx = 0;
380          idx < MIN(tpm_cmd_get_size(&s->buffer), s->be_buffer_size);
381          idx++) {
382         printf("%c%02x%s",
383                s->rw_offset == idx ? '>' : ' ',
384                s->buffer[idx],
385                ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
386     }
387     printf("\n");
388 }
389 #endif
390 
391 /*
392  * Read a register of the TIS interface
393  * See specs pages 33-63 for description of the registers
394  */
395 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
396                                   unsigned size)
397 {
398     TPMState *s = opaque;
399     uint16_t offset = addr & 0xffc;
400     uint8_t shift = (addr & 0x3) * 8;
401     uint32_t val = 0xffffffff;
402     uint8_t locty = tpm_tis_locality_from_addr(addr);
403     uint32_t avail;
404     uint8_t v;
405 
406     if (tpm_backend_had_startup_error(s->be_driver)) {
407         return 0;
408     }
409 
410     switch (offset) {
411     case TPM_TIS_REG_ACCESS:
412         /* never show the SEIZE flag even though we use it internally */
413         val = s->loc[locty].access & ~TPM_TIS_ACCESS_SEIZE;
414         /* the pending flag is always calculated */
415         if (tpm_tis_check_request_use_except(s, locty)) {
416             val |= TPM_TIS_ACCESS_PENDING_REQUEST;
417         }
418         val |= !tpm_backend_get_tpm_established_flag(s->be_driver);
419         break;
420     case TPM_TIS_REG_INT_ENABLE:
421         val = s->loc[locty].inte;
422         break;
423     case TPM_TIS_REG_INT_VECTOR:
424         val = s->irq_num;
425         break;
426     case TPM_TIS_REG_INT_STATUS:
427         val = s->loc[locty].ints;
428         break;
429     case TPM_TIS_REG_INTF_CAPABILITY:
430         switch (s->be_tpm_version) {
431         case TPM_VERSION_UNSPEC:
432             val = 0;
433             break;
434         case TPM_VERSION_1_2:
435             val = TPM_TIS_CAPABILITIES_SUPPORTED1_3;
436             break;
437         case TPM_VERSION_2_0:
438             val = TPM_TIS_CAPABILITIES_SUPPORTED2_0;
439             break;
440         }
441         break;
442     case TPM_TIS_REG_STS:
443         if (s->active_locty == locty) {
444             if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
445                 val = TPM_TIS_BURST_COUNT(
446                        MIN(tpm_cmd_get_size(&s->buffer),
447                            s->be_buffer_size)
448                        - s->rw_offset) | s->loc[locty].sts;
449             } else {
450                 avail = s->be_buffer_size - s->rw_offset;
451                 /*
452                  * byte-sized reads should not return 0x00 for 0x100
453                  * available bytes.
454                  */
455                 if (size == 1 && avail > 0xff) {
456                     avail = 0xff;
457                 }
458                 val = TPM_TIS_BURST_COUNT(avail) | s->loc[locty].sts;
459             }
460         }
461         break;
462     case TPM_TIS_REG_DATA_FIFO:
463     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
464         if (s->active_locty == locty) {
465             if (size > 4 - (addr & 0x3)) {
466                 /* prevent access beyond FIFO */
467                 size = 4 - (addr & 0x3);
468             }
469             val = 0;
470             shift = 0;
471             while (size > 0) {
472                 switch (s->loc[locty].state) {
473                 case TPM_TIS_STATE_COMPLETION:
474                     v = tpm_tis_data_read(s, locty);
475                     break;
476                 default:
477                     v = TPM_TIS_NO_DATA_BYTE;
478                     break;
479                 }
480                 val |= (v << shift);
481                 shift += 8;
482                 size--;
483             }
484             shift = 0; /* no more adjustments */
485         }
486         break;
487     case TPM_TIS_REG_INTERFACE_ID:
488         val = s->loc[locty].iface_id;
489         break;
490     case TPM_TIS_REG_DID_VID:
491         val = (TPM_TIS_TPM_DID << 16) | TPM_TIS_TPM_VID;
492         break;
493     case TPM_TIS_REG_RID:
494         val = TPM_TIS_TPM_RID;
495         break;
496 #ifdef DEBUG_TIS
497     case TPM_TIS_REG_DEBUG:
498         tpm_tis_dump_state(opaque, addr);
499         break;
500 #endif
501     }
502 
503     if (shift) {
504         val >>= shift;
505     }
506 
507     trace_tpm_tis_mmio_read(size, addr, val);
508 
509     return val;
510 }
511 
512 /*
513  * Write a value to a register of the TIS interface
514  * See specs pages 33-63 for description of the registers
515  */
516 static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
517                                uint64_t val, unsigned size)
518 {
519     TPMState *s = opaque;
520     uint16_t off = addr & 0xffc;
521     uint8_t shift = (addr & 0x3) * 8;
522     uint8_t locty = tpm_tis_locality_from_addr(addr);
523     uint8_t active_locty, l;
524     int c, set_new_locty = 1;
525     uint16_t len;
526     uint32_t mask = (size == 1) ? 0xff : ((size == 2) ? 0xffff : ~0);
527 
528     trace_tpm_tis_mmio_write(size, addr, val);
529 
530     if (locty == 4) {
531         trace_tpm_tis_mmio_write_locty4();
532         return;
533     }
534 
535     if (tpm_backend_had_startup_error(s->be_driver)) {
536         return;
537     }
538 
539     val &= mask;
540 
541     if (shift) {
542         val <<= shift;
543         mask <<= shift;
544     }
545 
546     mask ^= 0xffffffff;
547 
548     switch (off) {
549     case TPM_TIS_REG_ACCESS:
550 
551         if ((val & TPM_TIS_ACCESS_SEIZE)) {
552             val &= ~(TPM_TIS_ACCESS_REQUEST_USE |
553                      TPM_TIS_ACCESS_ACTIVE_LOCALITY);
554         }
555 
556         active_locty = s->active_locty;
557 
558         if ((val & TPM_TIS_ACCESS_ACTIVE_LOCALITY)) {
559             /* give up locality if currently owned */
560             if (s->active_locty == locty) {
561                 trace_tpm_tis_mmio_write_release_locty(locty);
562 
563                 uint8_t newlocty = TPM_TIS_NO_LOCALITY;
564                 /* anybody wants the locality ? */
565                 for (c = TPM_TIS_NUM_LOCALITIES - 1; c >= 0; c--) {
566                     if ((s->loc[c].access & TPM_TIS_ACCESS_REQUEST_USE)) {
567                         trace_tpm_tis_mmio_write_locty_req_use(c);
568                         newlocty = c;
569                         break;
570                     }
571                 }
572                 trace_tpm_tis_mmio_write_next_locty(newlocty);
573 
574                 if (TPM_TIS_IS_VALID_LOCTY(newlocty)) {
575                     set_new_locty = 0;
576                     tpm_tis_prep_abort(s, locty, newlocty);
577                 } else {
578                     active_locty = TPM_TIS_NO_LOCALITY;
579                 }
580             } else {
581                 /* not currently the owner; clear a pending request */
582                 s->loc[locty].access &= ~TPM_TIS_ACCESS_REQUEST_USE;
583             }
584         }
585 
586         if ((val & TPM_TIS_ACCESS_BEEN_SEIZED)) {
587             s->loc[locty].access &= ~TPM_TIS_ACCESS_BEEN_SEIZED;
588         }
589 
590         if ((val & TPM_TIS_ACCESS_SEIZE)) {
591             /*
592              * allow seize if a locality is active and the requesting
593              * locality is higher than the one that's active
594              * OR
595              * allow seize for requesting locality if no locality is
596              * active
597              */
598             while ((TPM_TIS_IS_VALID_LOCTY(s->active_locty) &&
599                     locty > s->active_locty) ||
600                     !TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
601                 bool higher_seize = FALSE;
602 
603                 /* already a pending SEIZE ? */
604                 if ((s->loc[locty].access & TPM_TIS_ACCESS_SEIZE)) {
605                     break;
606                 }
607 
608                 /* check for ongoing seize by a higher locality */
609                 for (l = locty + 1; l < TPM_TIS_NUM_LOCALITIES; l++) {
610                     if ((s->loc[l].access & TPM_TIS_ACCESS_SEIZE)) {
611                         higher_seize = TRUE;
612                         break;
613                     }
614                 }
615 
616                 if (higher_seize) {
617                     break;
618                 }
619 
620                 /* cancel any seize by a lower locality */
621                 for (l = 0; l < locty - 1; l++) {
622                     s->loc[l].access &= ~TPM_TIS_ACCESS_SEIZE;
623                 }
624 
625                 s->loc[locty].access |= TPM_TIS_ACCESS_SEIZE;
626 
627                 trace_tpm_tis_mmio_write_locty_seized(locty, s->active_locty);
628                 trace_tpm_tis_mmio_write_init_abort();
629 
630                 set_new_locty = 0;
631                 tpm_tis_prep_abort(s, s->active_locty, locty);
632                 break;
633             }
634         }
635 
636         if ((val & TPM_TIS_ACCESS_REQUEST_USE)) {
637             if (s->active_locty != locty) {
638                 if (TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
639                     s->loc[locty].access |= TPM_TIS_ACCESS_REQUEST_USE;
640                 } else {
641                     /* no locality active -> make this one active now */
642                     active_locty = locty;
643                 }
644             }
645         }
646 
647         if (set_new_locty) {
648             tpm_tis_new_active_locality(s, active_locty);
649         }
650 
651         break;
652     case TPM_TIS_REG_INT_ENABLE:
653         if (s->active_locty != locty) {
654             break;
655         }
656 
657         s->loc[locty].inte &= mask;
658         s->loc[locty].inte |= (val & (TPM_TIS_INT_ENABLED |
659                                         TPM_TIS_INT_POLARITY_MASK |
660                                         TPM_TIS_INTERRUPTS_SUPPORTED));
661         break;
662     case TPM_TIS_REG_INT_VECTOR:
663         /* hard wired -- ignore */
664         break;
665     case TPM_TIS_REG_INT_STATUS:
666         if (s->active_locty != locty) {
667             break;
668         }
669 
670         /* clearing of interrupt flags */
671         if (((val & TPM_TIS_INTERRUPTS_SUPPORTED)) &&
672             (s->loc[locty].ints & TPM_TIS_INTERRUPTS_SUPPORTED)) {
673             s->loc[locty].ints &= ~val;
674             if (s->loc[locty].ints == 0) {
675                 qemu_irq_lower(s->irq);
676                 trace_tpm_tis_mmio_write_lowering_irq();
677             }
678         }
679         s->loc[locty].ints &= ~(val & TPM_TIS_INTERRUPTS_SUPPORTED);
680         break;
681     case TPM_TIS_REG_STS:
682         if (s->active_locty != locty) {
683             break;
684         }
685 
686         if (s->be_tpm_version == TPM_VERSION_2_0) {
687             /* some flags that are only supported for TPM 2 */
688             if (val & TPM_TIS_STS_COMMAND_CANCEL) {
689                 if (s->loc[locty].state == TPM_TIS_STATE_EXECUTION) {
690                     /*
691                      * request the backend to cancel. Some backends may not
692                      * support it
693                      */
694                     tpm_backend_cancel_cmd(s->be_driver);
695                 }
696             }
697 
698             if (val & TPM_TIS_STS_RESET_ESTABLISHMENT_BIT) {
699                 if (locty == 3 || locty == 4) {
700                     tpm_backend_reset_tpm_established_flag(s->be_driver, locty);
701                 }
702             }
703         }
704 
705         val &= (TPM_TIS_STS_COMMAND_READY | TPM_TIS_STS_TPM_GO |
706                 TPM_TIS_STS_RESPONSE_RETRY);
707 
708         if (val == TPM_TIS_STS_COMMAND_READY) {
709             switch (s->loc[locty].state) {
710 
711             case TPM_TIS_STATE_READY:
712                 s->rw_offset = 0;
713             break;
714 
715             case TPM_TIS_STATE_IDLE:
716                 tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_COMMAND_READY);
717                 s->loc[locty].state = TPM_TIS_STATE_READY;
718                 tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
719             break;
720 
721             case TPM_TIS_STATE_EXECUTION:
722             case TPM_TIS_STATE_RECEPTION:
723                 /* abort currently running command */
724                 trace_tpm_tis_mmio_write_init_abort();
725                 tpm_tis_prep_abort(s, locty, locty);
726             break;
727 
728             case TPM_TIS_STATE_COMPLETION:
729                 s->rw_offset = 0;
730                 /* shortcut to ready state with C/R set */
731                 s->loc[locty].state = TPM_TIS_STATE_READY;
732                 if (!(s->loc[locty].sts & TPM_TIS_STS_COMMAND_READY)) {
733                     tpm_tis_sts_set(&s->loc[locty],
734                                     TPM_TIS_STS_COMMAND_READY);
735                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
736                 }
737                 s->loc[locty].sts &= ~(TPM_TIS_STS_DATA_AVAILABLE);
738             break;
739 
740             }
741         } else if (val == TPM_TIS_STS_TPM_GO) {
742             switch (s->loc[locty].state) {
743             case TPM_TIS_STATE_RECEPTION:
744                 if ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) == 0) {
745                     tpm_tis_tpm_send(s, locty);
746                 }
747                 break;
748             default:
749                 /* ignore */
750                 break;
751             }
752         } else if (val == TPM_TIS_STS_RESPONSE_RETRY) {
753             switch (s->loc[locty].state) {
754             case TPM_TIS_STATE_COMPLETION:
755                 s->rw_offset = 0;
756                 tpm_tis_sts_set(&s->loc[locty],
757                                 TPM_TIS_STS_VALID|
758                                 TPM_TIS_STS_DATA_AVAILABLE);
759                 break;
760             default:
761                 /* ignore */
762                 break;
763             }
764         }
765         break;
766     case TPM_TIS_REG_DATA_FIFO:
767     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
768         /* data fifo */
769         if (s->active_locty != locty) {
770             break;
771         }
772 
773         if (s->loc[locty].state == TPM_TIS_STATE_IDLE ||
774             s->loc[locty].state == TPM_TIS_STATE_EXECUTION ||
775             s->loc[locty].state == TPM_TIS_STATE_COMPLETION) {
776             /* drop the byte */
777         } else {
778             trace_tpm_tis_mmio_write_data2send(val, size);
779             if (s->loc[locty].state == TPM_TIS_STATE_READY) {
780                 s->loc[locty].state = TPM_TIS_STATE_RECEPTION;
781                 tpm_tis_sts_set(&s->loc[locty],
782                                 TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
783             }
784 
785             val >>= shift;
786             if (size > 4 - (addr & 0x3)) {
787                 /* prevent access beyond FIFO */
788                 size = 4 - (addr & 0x3);
789             }
790 
791             while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
792                 if (s->rw_offset < s->be_buffer_size) {
793                     s->buffer[s->rw_offset++] =
794                         (uint8_t)val;
795                     val >>= 8;
796                     size--;
797                 } else {
798                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
799                 }
800             }
801 
802             /* check for complete packet */
803             if (s->rw_offset > 5 &&
804                 (s->loc[locty].sts & TPM_TIS_STS_EXPECT)) {
805                 /* we have a packet length - see if we have all of it */
806                 bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
807 
808                 len = tpm_cmd_get_size(&s->buffer);
809                 if (len > s->rw_offset) {
810                     tpm_tis_sts_set(&s->loc[locty],
811                                     TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
812                 } else {
813                     /* packet complete */
814                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
815                 }
816                 if (need_irq) {
817                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
818                 }
819             }
820         }
821         break;
822     case TPM_TIS_REG_INTERFACE_ID:
823         if (val & TPM_TIS_IFACE_ID_INT_SEL_LOCK) {
824             for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
825                 s->loc[l].iface_id |= TPM_TIS_IFACE_ID_INT_SEL_LOCK;
826             }
827         }
828         break;
829     }
830 }
831 
832 static const MemoryRegionOps tpm_tis_memory_ops = {
833     .read = tpm_tis_mmio_read,
834     .write = tpm_tis_mmio_write,
835     .endianness = DEVICE_LITTLE_ENDIAN,
836     .valid = {
837         .min_access_size = 1,
838         .max_access_size = 4,
839     },
840 };
841 
842 /*
843  * Get the TPMVersion of the backend device being used
844  */
845 static enum TPMVersion tpm_tis_get_tpm_version(TPMIf *ti)
846 {
847     TPMState *s = TPM(ti);
848 
849     if (tpm_backend_had_startup_error(s->be_driver)) {
850         return TPM_VERSION_UNSPEC;
851     }
852 
853     return tpm_backend_get_tpm_version(s->be_driver);
854 }
855 
856 /*
857  * This function is called when the machine starts, resets or due to
858  * S3 resume.
859  */
860 static void tpm_tis_reset(DeviceState *dev)
861 {
862     TPMState *s = TPM(dev);
863     int c;
864 
865     s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
866     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->be_driver),
867                             TPM_TIS_BUFFER_MAX);
868 
869     tpm_backend_reset(s->be_driver);
870 
871     s->active_locty = TPM_TIS_NO_LOCALITY;
872     s->next_locty = TPM_TIS_NO_LOCALITY;
873     s->aborting_locty = TPM_TIS_NO_LOCALITY;
874 
875     for (c = 0; c < TPM_TIS_NUM_LOCALITIES; c++) {
876         s->loc[c].access = TPM_TIS_ACCESS_TPM_REG_VALID_STS;
877         switch (s->be_tpm_version) {
878         case TPM_VERSION_UNSPEC:
879             break;
880         case TPM_VERSION_1_2:
881             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY1_2;
882             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
883             break;
884         case TPM_VERSION_2_0:
885             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY2_0;
886             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0;
887             break;
888         }
889         s->loc[c].inte = TPM_TIS_INT_POLARITY_LOW_LEVEL;
890         s->loc[c].ints = 0;
891         s->loc[c].state = TPM_TIS_STATE_IDLE;
892 
893         s->rw_offset = 0;
894     }
895 
896     tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size);
897 }
898 
899 /* persistent state handling */
900 
901 static int tpm_tis_pre_save(void *opaque)
902 {
903     TPMState *s = opaque;
904     uint8_t locty = s->active_locty;
905 
906     trace_tpm_tis_pre_save(locty, s->rw_offset);
907 
908     if (DEBUG_TIS) {
909         tpm_tis_dump_state(opaque, 0);
910     }
911 
912     /*
913      * Synchronize with backend completion.
914      */
915     tpm_backend_finish_sync(s->be_driver);
916 
917     return 0;
918 }
919 
920 static const VMStateDescription vmstate_locty = {
921     .name = "tpm-tis/locty",
922     .version_id = 0,
923     .fields      = (VMStateField[]) {
924         VMSTATE_UINT32(state, TPMLocality),
925         VMSTATE_UINT32(inte, TPMLocality),
926         VMSTATE_UINT32(ints, TPMLocality),
927         VMSTATE_UINT8(access, TPMLocality),
928         VMSTATE_UINT32(sts, TPMLocality),
929         VMSTATE_UINT32(iface_id, TPMLocality),
930         VMSTATE_END_OF_LIST(),
931     }
932 };
933 
934 static const VMStateDescription vmstate_tpm_tis = {
935     .name = "tpm-tis",
936     .version_id = 0,
937     .pre_save  = tpm_tis_pre_save,
938     .fields = (VMStateField[]) {
939         VMSTATE_BUFFER(buffer, TPMState),
940         VMSTATE_UINT16(rw_offset, TPMState),
941         VMSTATE_UINT8(active_locty, TPMState),
942         VMSTATE_UINT8(aborting_locty, TPMState),
943         VMSTATE_UINT8(next_locty, TPMState),
944 
945         VMSTATE_STRUCT_ARRAY(loc, TPMState, TPM_TIS_NUM_LOCALITIES, 0,
946                              vmstate_locty, TPMLocality),
947 
948         VMSTATE_END_OF_LIST()
949     }
950 };
951 
952 static Property tpm_tis_properties[] = {
953     DEFINE_PROP_UINT32("irq", TPMState, irq_num, TPM_TIS_IRQ),
954     DEFINE_PROP_TPMBE("tpmdev", TPMState, be_driver),
955     DEFINE_PROP_END_OF_LIST(),
956 };
957 
958 static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
959 {
960     TPMState *s = TPM(dev);
961 
962     if (!tpm_find()) {
963         error_setg(errp, "at most one TPM device is permitted");
964         return;
965     }
966 
967     if (!s->be_driver) {
968         error_setg(errp, "'tpmdev' property is required");
969         return;
970     }
971     if (s->irq_num > 15) {
972         error_setg(errp, "IRQ %d is outside valid range of 0 to 15",
973                    s->irq_num);
974         return;
975     }
976 
977     isa_init_irq(&s->busdev, &s->irq, s->irq_num);
978 
979     memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
980                                 TPM_TIS_ADDR_BASE, &s->mmio);
981 }
982 
983 static void tpm_tis_initfn(Object *obj)
984 {
985     TPMState *s = TPM(obj);
986 
987     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_tis_memory_ops,
988                           s, "tpm-tis-mmio",
989                           TPM_TIS_NUM_LOCALITIES << TPM_TIS_LOCALITY_SHIFT);
990 }
991 
992 static void tpm_tis_class_init(ObjectClass *klass, void *data)
993 {
994     DeviceClass *dc = DEVICE_CLASS(klass);
995     TPMIfClass *tc = TPM_IF_CLASS(klass);
996 
997     dc->realize = tpm_tis_realizefn;
998     dc->props = tpm_tis_properties;
999     dc->reset = tpm_tis_reset;
1000     dc->vmsd  = &vmstate_tpm_tis;
1001     tc->model = TPM_MODEL_TPM_TIS;
1002     tc->get_version = tpm_tis_get_tpm_version;
1003     tc->request_completed = tpm_tis_request_completed;
1004 }
1005 
1006 static const TypeInfo tpm_tis_info = {
1007     .name = TYPE_TPM_TIS,
1008     .parent = TYPE_ISA_DEVICE,
1009     .instance_size = sizeof(TPMState),
1010     .instance_init = tpm_tis_initfn,
1011     .class_init  = tpm_tis_class_init,
1012     .interfaces = (InterfaceInfo[]) {
1013         { TYPE_TPM_IF },
1014         { }
1015     }
1016 };
1017 
1018 static void tpm_tis_register(void)
1019 {
1020     type_register_static(&tpm_tis_info);
1021 }
1022 
1023 type_init(tpm_tis_register)
1024