xref: /openbmc/qemu/hw/tpm/tpm_tis_common.c (revision f6476697)
1 /*
2  * tpm_tis_common.c - QEMU's TPM TIS interface emulator
3  * device agnostic functions
4  *
5  * Copyright (C) 2006,2010-2013 IBM Corporation
6  *
7  * Authors:
8  *  Stefan Berger <stefanb@us.ibm.com>
9  *  David Safford <safford@us.ibm.com>
10  *
11  * Xen 4 support: Andrease Niederl <andreas.niederl@iaik.tugraz.at>
12  *
13  * This work is licensed under the terms of the GNU GPL, version 2 or later.
14  * See the COPYING file in the top-level directory.
15  *
16  * Implementation of the TIS interface according to specs found at
17  * http://www.trustedcomputinggroup.org. This implementation currently
18  * supports version 1.3, 21 March 2013
19  * In the developers menu choose the PC Client section then find the TIS
20  * specification.
21  *
22  * TPM TIS for TPM 2 implementation following TCG PC Client Platform
23  * TPM Profile (PTP) Specification, Familiy 2.0, Revision 00.43
24  */
25 #include "qemu/osdep.h"
26 #include "hw/irq.h"
27 #include "hw/isa/isa.h"
28 #include "qapi/error.h"
29 #include "qemu/module.h"
30 
31 #include "hw/acpi/tpm.h"
32 #include "hw/pci/pci_ids.h"
33 #include "hw/qdev-properties.h"
34 #include "migration/vmstate.h"
35 #include "sysemu/tpm_backend.h"
36 #include "sysemu/tpm_util.h"
37 #include "tpm_ppi.h"
38 #include "trace.h"
39 
40 #include "tpm_tis.h"
41 
42 #define DEBUG_TIS 0
43 
44 /* local prototypes */
45 
46 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
47                                   unsigned size);
48 
49 /* utility functions */
50 
51 static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
52 {
53     return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
54 }
55 
56 
57 /*
58  * Set the given flags in the STS register by clearing the register but
59  * preserving the SELFTEST_DONE and TPM_FAMILY_MASK flags and then setting
60  * the new flags.
61  *
62  * The SELFTEST_DONE flag is acquired from the backend that determines it by
63  * peeking into TPM commands.
64  *
65  * A VM suspend/resume will preserve the flag by storing it into the VM
66  * device state, but the backend will not remember it when QEMU is started
67  * again. Therefore, we cache the flag here. Once set, it will not be unset
68  * except by a reset.
69  */
70 static void tpm_tis_sts_set(TPMLocality *l, uint32_t flags)
71 {
72     l->sts &= TPM_TIS_STS_SELFTEST_DONE | TPM_TIS_STS_TPM_FAMILY_MASK;
73     l->sts |= flags;
74 }
75 
76 /*
77  * Send a request to the TPM.
78  */
79 static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
80 {
81     tpm_util_show_buffer(s->buffer, s->be_buffer_size, "To TPM");
82 
83     /*
84      * rw_offset serves as length indicator for length of data;
85      * it's reset when the response comes back
86      */
87     s->loc[locty].state = TPM_TIS_STATE_EXECUTION;
88 
89     s->cmd = (TPMBackendCmd) {
90         .locty = locty,
91         .in = s->buffer,
92         .in_len = s->rw_offset,
93         .out = s->buffer,
94         .out_len = s->be_buffer_size,
95     };
96 
97     tpm_backend_deliver_request(s->be_driver, &s->cmd);
98 }
99 
100 /* raise an interrupt if allowed */
101 static void tpm_tis_raise_irq(TPMState *s, uint8_t locty, uint32_t irqmask)
102 {
103     if (!TPM_TIS_IS_VALID_LOCTY(locty)) {
104         return;
105     }
106 
107     if ((s->loc[locty].inte & TPM_TIS_INT_ENABLED) &&
108         (s->loc[locty].inte & irqmask)) {
109         trace_tpm_tis_raise_irq(irqmask);
110         qemu_irq_raise(s->irq);
111         s->loc[locty].ints |= irqmask;
112     }
113 }
114 
115 static uint32_t tpm_tis_check_request_use_except(TPMState *s, uint8_t locty)
116 {
117     uint8_t l;
118 
119     for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
120         if (l == locty) {
121             continue;
122         }
123         if ((s->loc[l].access & TPM_TIS_ACCESS_REQUEST_USE)) {
124             return 1;
125         }
126     }
127 
128     return 0;
129 }
130 
131 static void tpm_tis_new_active_locality(TPMState *s, uint8_t new_active_locty)
132 {
133     bool change = (s->active_locty != new_active_locty);
134     bool is_seize;
135     uint8_t mask;
136 
137     if (change && TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
138         is_seize = TPM_TIS_IS_VALID_LOCTY(new_active_locty) &&
139                    s->loc[new_active_locty].access & TPM_TIS_ACCESS_SEIZE;
140 
141         if (is_seize) {
142             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY);
143         } else {
144             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY|
145                      TPM_TIS_ACCESS_REQUEST_USE);
146         }
147         /* reset flags on the old active locality */
148         s->loc[s->active_locty].access &= mask;
149 
150         if (is_seize) {
151             s->loc[s->active_locty].access |= TPM_TIS_ACCESS_BEEN_SEIZED;
152         }
153     }
154 
155     s->active_locty = new_active_locty;
156 
157     trace_tpm_tis_new_active_locality(s->active_locty);
158 
159     if (TPM_TIS_IS_VALID_LOCTY(new_active_locty)) {
160         /* set flags on the new active locality */
161         s->loc[new_active_locty].access |= TPM_TIS_ACCESS_ACTIVE_LOCALITY;
162         s->loc[new_active_locty].access &= ~(TPM_TIS_ACCESS_REQUEST_USE |
163                                                TPM_TIS_ACCESS_SEIZE);
164     }
165 
166     if (change) {
167         tpm_tis_raise_irq(s, s->active_locty, TPM_TIS_INT_LOCALITY_CHANGED);
168     }
169 }
170 
171 /* abort -- this function switches the locality */
172 static void tpm_tis_abort(TPMState *s)
173 {
174     s->rw_offset = 0;
175 
176     trace_tpm_tis_abort(s->next_locty);
177 
178     /*
179      * Need to react differently depending on who's aborting now and
180      * which locality will become active afterwards.
181      */
182     if (s->aborting_locty == s->next_locty) {
183         s->loc[s->aborting_locty].state = TPM_TIS_STATE_READY;
184         tpm_tis_sts_set(&s->loc[s->aborting_locty],
185                         TPM_TIS_STS_COMMAND_READY);
186         tpm_tis_raise_irq(s, s->aborting_locty, TPM_TIS_INT_COMMAND_READY);
187     }
188 
189     /* locality after abort is another one than the current one */
190     tpm_tis_new_active_locality(s, s->next_locty);
191 
192     s->next_locty = TPM_TIS_NO_LOCALITY;
193     /* nobody's aborting a command anymore */
194     s->aborting_locty = TPM_TIS_NO_LOCALITY;
195 }
196 
197 /* prepare aborting current command */
198 static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
199 {
200     uint8_t busy_locty;
201 
202     assert(TPM_TIS_IS_VALID_LOCTY(newlocty));
203 
204     s->aborting_locty = locty; /* may also be TPM_TIS_NO_LOCALITY */
205     s->next_locty = newlocty;  /* locality after successful abort */
206 
207     /*
208      * only abort a command using an interrupt if currently executing
209      * a command AND if there's a valid connection to the vTPM.
210      */
211     for (busy_locty = 0; busy_locty < TPM_TIS_NUM_LOCALITIES; busy_locty++) {
212         if (s->loc[busy_locty].state == TPM_TIS_STATE_EXECUTION) {
213             /*
214              * request the backend to cancel. Some backends may not
215              * support it
216              */
217             tpm_backend_cancel_cmd(s->be_driver);
218             return;
219         }
220     }
221 
222     tpm_tis_abort(s);
223 }
224 
225 /*
226  * Callback from the TPM to indicate that the response was received.
227  */
228 void tpm_tis_request_completed(TPMState *s, int ret)
229 {
230     uint8_t locty = s->cmd.locty;
231     uint8_t l;
232 
233     assert(TPM_TIS_IS_VALID_LOCTY(locty));
234 
235     if (s->cmd.selftest_done) {
236         for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
237             s->loc[l].sts |= TPM_TIS_STS_SELFTEST_DONE;
238         }
239     }
240 
241     /* FIXME: report error if ret != 0 */
242     tpm_tis_sts_set(&s->loc[locty],
243                     TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
244     s->loc[locty].state = TPM_TIS_STATE_COMPLETION;
245     s->rw_offset = 0;
246 
247     tpm_util_show_buffer(s->buffer, s->be_buffer_size, "From TPM");
248 
249     if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
250         tpm_tis_abort(s);
251     }
252 
253     tpm_tis_raise_irq(s, locty,
254                       TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
255 }
256 
257 /*
258  * Read a byte of response data
259  */
260 static uint32_t tpm_tis_data_read(TPMState *s, uint8_t locty)
261 {
262     uint32_t ret = TPM_TIS_NO_DATA_BYTE;
263     uint16_t len;
264 
265     if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
266         len = MIN(tpm_cmd_get_size(&s->buffer),
267                   s->be_buffer_size);
268 
269         ret = s->buffer[s->rw_offset++];
270         if (s->rw_offset >= len) {
271             /* got last byte */
272             tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
273             tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
274         }
275         trace_tpm_tis_data_read(ret, s->rw_offset - 1);
276     }
277 
278     return ret;
279 }
280 
281 #ifdef DEBUG_TIS
282 static void tpm_tis_dump_state(TPMState *s, hwaddr addr)
283 {
284     static const unsigned regs[] = {
285         TPM_TIS_REG_ACCESS,
286         TPM_TIS_REG_INT_ENABLE,
287         TPM_TIS_REG_INT_VECTOR,
288         TPM_TIS_REG_INT_STATUS,
289         TPM_TIS_REG_INTF_CAPABILITY,
290         TPM_TIS_REG_STS,
291         TPM_TIS_REG_DID_VID,
292         TPM_TIS_REG_RID,
293         0xfff};
294     int idx;
295     uint8_t locty = tpm_tis_locality_from_addr(addr);
296     hwaddr base = addr & ~0xfff;
297 
298     printf("tpm_tis: active locality      : %d\n"
299            "tpm_tis: state of locality %d : %d\n"
300            "tpm_tis: register dump:\n",
301            s->active_locty,
302            locty, s->loc[locty].state);
303 
304     for (idx = 0; regs[idx] != 0xfff; idx++) {
305         printf("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
306                (int)tpm_tis_mmio_read(s, base + regs[idx], 4));
307     }
308 
309     printf("tpm_tis: r/w offset    : %d\n"
310            "tpm_tis: result buffer : ",
311            s->rw_offset);
312     for (idx = 0;
313          idx < MIN(tpm_cmd_get_size(&s->buffer), s->be_buffer_size);
314          idx++) {
315         printf("%c%02x%s",
316                s->rw_offset == idx ? '>' : ' ',
317                s->buffer[idx],
318                ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
319     }
320     printf("\n");
321 }
322 #endif
323 
324 /*
325  * Read a register of the TIS interface
326  * See specs pages 33-63 for description of the registers
327  */
328 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
329                                   unsigned size)
330 {
331     TPMState *s = opaque;
332     uint16_t offset = addr & 0xffc;
333     uint8_t shift = (addr & 0x3) * 8;
334     uint32_t val = 0xffffffff;
335     uint8_t locty = tpm_tis_locality_from_addr(addr);
336     uint32_t avail;
337     uint8_t v;
338 
339     if (tpm_backend_had_startup_error(s->be_driver)) {
340         return 0;
341     }
342 
343     switch (offset) {
344     case TPM_TIS_REG_ACCESS:
345         /* never show the SEIZE flag even though we use it internally */
346         val = s->loc[locty].access & ~TPM_TIS_ACCESS_SEIZE;
347         /* the pending flag is always calculated */
348         if (tpm_tis_check_request_use_except(s, locty)) {
349             val |= TPM_TIS_ACCESS_PENDING_REQUEST;
350         }
351         val |= !tpm_backend_get_tpm_established_flag(s->be_driver);
352         break;
353     case TPM_TIS_REG_INT_ENABLE:
354         val = s->loc[locty].inte;
355         break;
356     case TPM_TIS_REG_INT_VECTOR:
357         val = s->irq_num;
358         break;
359     case TPM_TIS_REG_INT_STATUS:
360         val = s->loc[locty].ints;
361         break;
362     case TPM_TIS_REG_INTF_CAPABILITY:
363         switch (s->be_tpm_version) {
364         case TPM_VERSION_UNSPEC:
365             val = 0;
366             break;
367         case TPM_VERSION_1_2:
368             val = TPM_TIS_CAPABILITIES_SUPPORTED1_3;
369             break;
370         case TPM_VERSION_2_0:
371             val = TPM_TIS_CAPABILITIES_SUPPORTED2_0;
372             break;
373         }
374         break;
375     case TPM_TIS_REG_STS:
376         if (s->active_locty == locty) {
377             if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
378                 val = TPM_TIS_BURST_COUNT(
379                        MIN(tpm_cmd_get_size(&s->buffer),
380                            s->be_buffer_size)
381                        - s->rw_offset) | s->loc[locty].sts;
382             } else {
383                 avail = s->be_buffer_size - s->rw_offset;
384                 /*
385                  * byte-sized reads should not return 0x00 for 0x100
386                  * available bytes.
387                  */
388                 if (size == 1 && avail > 0xff) {
389                     avail = 0xff;
390                 }
391                 val = TPM_TIS_BURST_COUNT(avail) | s->loc[locty].sts;
392             }
393         }
394         break;
395     case TPM_TIS_REG_DATA_FIFO:
396     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
397         if (s->active_locty == locty) {
398             if (size > 4 - (addr & 0x3)) {
399                 /* prevent access beyond FIFO */
400                 size = 4 - (addr & 0x3);
401             }
402             val = 0;
403             shift = 0;
404             while (size > 0) {
405                 switch (s->loc[locty].state) {
406                 case TPM_TIS_STATE_COMPLETION:
407                     v = tpm_tis_data_read(s, locty);
408                     break;
409                 default:
410                     v = TPM_TIS_NO_DATA_BYTE;
411                     break;
412                 }
413                 val |= (v << shift);
414                 shift += 8;
415                 size--;
416             }
417             shift = 0; /* no more adjustments */
418         }
419         break;
420     case TPM_TIS_REG_INTERFACE_ID:
421         val = s->loc[locty].iface_id;
422         break;
423     case TPM_TIS_REG_DID_VID:
424         val = (TPM_TIS_TPM_DID << 16) | TPM_TIS_TPM_VID;
425         break;
426     case TPM_TIS_REG_RID:
427         val = TPM_TIS_TPM_RID;
428         break;
429 #ifdef DEBUG_TIS
430     case TPM_TIS_REG_DEBUG:
431         tpm_tis_dump_state(s, addr);
432         break;
433 #endif
434     }
435 
436     if (shift) {
437         val >>= shift;
438     }
439 
440     trace_tpm_tis_mmio_read(size, addr, val);
441 
442     return val;
443 }
444 
445 /*
446  * Write a value to a register of the TIS interface
447  * See specs pages 33-63 for description of the registers
448  */
449 static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
450                                uint64_t val, unsigned size)
451 {
452     TPMState *s = opaque;
453     uint16_t off = addr & 0xffc;
454     uint8_t shift = (addr & 0x3) * 8;
455     uint8_t locty = tpm_tis_locality_from_addr(addr);
456     uint8_t active_locty, l;
457     int c, set_new_locty = 1;
458     uint16_t len;
459     uint32_t mask = (size == 1) ? 0xff : ((size == 2) ? 0xffff : ~0);
460 
461     trace_tpm_tis_mmio_write(size, addr, val);
462 
463     if (locty == 4) {
464         trace_tpm_tis_mmio_write_locty4();
465         return;
466     }
467 
468     if (tpm_backend_had_startup_error(s->be_driver)) {
469         return;
470     }
471 
472     val &= mask;
473 
474     if (shift) {
475         val <<= shift;
476         mask <<= shift;
477     }
478 
479     mask ^= 0xffffffff;
480 
481     switch (off) {
482     case TPM_TIS_REG_ACCESS:
483 
484         if ((val & TPM_TIS_ACCESS_SEIZE)) {
485             val &= ~(TPM_TIS_ACCESS_REQUEST_USE |
486                      TPM_TIS_ACCESS_ACTIVE_LOCALITY);
487         }
488 
489         active_locty = s->active_locty;
490 
491         if ((val & TPM_TIS_ACCESS_ACTIVE_LOCALITY)) {
492             /* give up locality if currently owned */
493             if (s->active_locty == locty) {
494                 trace_tpm_tis_mmio_write_release_locty(locty);
495 
496                 uint8_t newlocty = TPM_TIS_NO_LOCALITY;
497                 /* anybody wants the locality ? */
498                 for (c = TPM_TIS_NUM_LOCALITIES - 1; c >= 0; c--) {
499                     if ((s->loc[c].access & TPM_TIS_ACCESS_REQUEST_USE)) {
500                         trace_tpm_tis_mmio_write_locty_req_use(c);
501                         newlocty = c;
502                         break;
503                     }
504                 }
505                 trace_tpm_tis_mmio_write_next_locty(newlocty);
506 
507                 if (TPM_TIS_IS_VALID_LOCTY(newlocty)) {
508                     set_new_locty = 0;
509                     tpm_tis_prep_abort(s, locty, newlocty);
510                 } else {
511                     active_locty = TPM_TIS_NO_LOCALITY;
512                 }
513             } else {
514                 /* not currently the owner; clear a pending request */
515                 s->loc[locty].access &= ~TPM_TIS_ACCESS_REQUEST_USE;
516             }
517         }
518 
519         if ((val & TPM_TIS_ACCESS_BEEN_SEIZED)) {
520             s->loc[locty].access &= ~TPM_TIS_ACCESS_BEEN_SEIZED;
521         }
522 
523         if ((val & TPM_TIS_ACCESS_SEIZE)) {
524             /*
525              * allow seize if a locality is active and the requesting
526              * locality is higher than the one that's active
527              * OR
528              * allow seize for requesting locality if no locality is
529              * active
530              */
531             while ((TPM_TIS_IS_VALID_LOCTY(s->active_locty) &&
532                     locty > s->active_locty) ||
533                     !TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
534                 bool higher_seize = false;
535 
536                 /* already a pending SEIZE ? */
537                 if ((s->loc[locty].access & TPM_TIS_ACCESS_SEIZE)) {
538                     break;
539                 }
540 
541                 /* check for ongoing seize by a higher locality */
542                 for (l = locty + 1; l < TPM_TIS_NUM_LOCALITIES; l++) {
543                     if ((s->loc[l].access & TPM_TIS_ACCESS_SEIZE)) {
544                         higher_seize = true;
545                         break;
546                     }
547                 }
548 
549                 if (higher_seize) {
550                     break;
551                 }
552 
553                 /* cancel any seize by a lower locality */
554                 for (l = 0; l < locty; l++) {
555                     s->loc[l].access &= ~TPM_TIS_ACCESS_SEIZE;
556                 }
557 
558                 s->loc[locty].access |= TPM_TIS_ACCESS_SEIZE;
559 
560                 trace_tpm_tis_mmio_write_locty_seized(locty, s->active_locty);
561                 trace_tpm_tis_mmio_write_init_abort();
562 
563                 set_new_locty = 0;
564                 tpm_tis_prep_abort(s, s->active_locty, locty);
565                 break;
566             }
567         }
568 
569         if ((val & TPM_TIS_ACCESS_REQUEST_USE)) {
570             if (s->active_locty != locty) {
571                 if (TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
572                     s->loc[locty].access |= TPM_TIS_ACCESS_REQUEST_USE;
573                 } else {
574                     /* no locality active -> make this one active now */
575                     active_locty = locty;
576                 }
577             }
578         }
579 
580         if (set_new_locty) {
581             tpm_tis_new_active_locality(s, active_locty);
582         }
583 
584         break;
585     case TPM_TIS_REG_INT_ENABLE:
586         if (s->active_locty != locty) {
587             break;
588         }
589 
590         s->loc[locty].inte &= mask;
591         s->loc[locty].inte |= (val & (TPM_TIS_INT_ENABLED |
592                                         TPM_TIS_INT_POLARITY_MASK |
593                                         TPM_TIS_INTERRUPTS_SUPPORTED));
594         break;
595     case TPM_TIS_REG_INT_VECTOR:
596         /* hard wired -- ignore */
597         break;
598     case TPM_TIS_REG_INT_STATUS:
599         if (s->active_locty != locty) {
600             break;
601         }
602 
603         /* clearing of interrupt flags */
604         if (((val & TPM_TIS_INTERRUPTS_SUPPORTED)) &&
605             (s->loc[locty].ints & TPM_TIS_INTERRUPTS_SUPPORTED)) {
606             s->loc[locty].ints &= ~val;
607             if (s->loc[locty].ints == 0) {
608                 qemu_irq_lower(s->irq);
609                 trace_tpm_tis_mmio_write_lowering_irq();
610             }
611         }
612         s->loc[locty].ints &= ~(val & TPM_TIS_INTERRUPTS_SUPPORTED);
613         break;
614     case TPM_TIS_REG_STS:
615         if (s->active_locty != locty) {
616             break;
617         }
618 
619         if (s->be_tpm_version == TPM_VERSION_2_0) {
620             /* some flags that are only supported for TPM 2 */
621             if (val & TPM_TIS_STS_COMMAND_CANCEL) {
622                 if (s->loc[locty].state == TPM_TIS_STATE_EXECUTION) {
623                     /*
624                      * request the backend to cancel. Some backends may not
625                      * support it
626                      */
627                     tpm_backend_cancel_cmd(s->be_driver);
628                 }
629             }
630 
631             if (val & TPM_TIS_STS_RESET_ESTABLISHMENT_BIT) {
632                 if (locty == 3 || locty == 4) {
633                     tpm_backend_reset_tpm_established_flag(s->be_driver, locty);
634                 }
635             }
636         }
637 
638         val &= (TPM_TIS_STS_COMMAND_READY | TPM_TIS_STS_TPM_GO |
639                 TPM_TIS_STS_RESPONSE_RETRY);
640 
641         if (val == TPM_TIS_STS_COMMAND_READY) {
642             switch (s->loc[locty].state) {
643 
644             case TPM_TIS_STATE_READY:
645                 s->rw_offset = 0;
646             break;
647 
648             case TPM_TIS_STATE_IDLE:
649                 tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_COMMAND_READY);
650                 s->loc[locty].state = TPM_TIS_STATE_READY;
651                 tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
652             break;
653 
654             case TPM_TIS_STATE_EXECUTION:
655             case TPM_TIS_STATE_RECEPTION:
656                 /* abort currently running command */
657                 trace_tpm_tis_mmio_write_init_abort();
658                 tpm_tis_prep_abort(s, locty, locty);
659             break;
660 
661             case TPM_TIS_STATE_COMPLETION:
662                 s->rw_offset = 0;
663                 /* shortcut to ready state with C/R set */
664                 s->loc[locty].state = TPM_TIS_STATE_READY;
665                 if (!(s->loc[locty].sts & TPM_TIS_STS_COMMAND_READY)) {
666                     tpm_tis_sts_set(&s->loc[locty],
667                                     TPM_TIS_STS_COMMAND_READY);
668                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
669                 }
670                 s->loc[locty].sts &= ~(TPM_TIS_STS_DATA_AVAILABLE);
671             break;
672 
673             }
674         } else if (val == TPM_TIS_STS_TPM_GO) {
675             switch (s->loc[locty].state) {
676             case TPM_TIS_STATE_RECEPTION:
677                 if ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) == 0) {
678                     tpm_tis_tpm_send(s, locty);
679                 }
680                 break;
681             default:
682                 /* ignore */
683                 break;
684             }
685         } else if (val == TPM_TIS_STS_RESPONSE_RETRY) {
686             switch (s->loc[locty].state) {
687             case TPM_TIS_STATE_COMPLETION:
688                 s->rw_offset = 0;
689                 tpm_tis_sts_set(&s->loc[locty],
690                                 TPM_TIS_STS_VALID|
691                                 TPM_TIS_STS_DATA_AVAILABLE);
692                 break;
693             default:
694                 /* ignore */
695                 break;
696             }
697         }
698         break;
699     case TPM_TIS_REG_DATA_FIFO:
700     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
701         /* data fifo */
702         if (s->active_locty != locty) {
703             break;
704         }
705 
706         if (s->loc[locty].state == TPM_TIS_STATE_IDLE ||
707             s->loc[locty].state == TPM_TIS_STATE_EXECUTION ||
708             s->loc[locty].state == TPM_TIS_STATE_COMPLETION) {
709             /* drop the byte */
710         } else {
711             trace_tpm_tis_mmio_write_data2send(val, size);
712             if (s->loc[locty].state == TPM_TIS_STATE_READY) {
713                 s->loc[locty].state = TPM_TIS_STATE_RECEPTION;
714                 tpm_tis_sts_set(&s->loc[locty],
715                                 TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
716             }
717 
718             val >>= shift;
719             if (size > 4 - (addr & 0x3)) {
720                 /* prevent access beyond FIFO */
721                 size = 4 - (addr & 0x3);
722             }
723 
724             while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
725                 if (s->rw_offset < s->be_buffer_size) {
726                     s->buffer[s->rw_offset++] =
727                         (uint8_t)val;
728                     val >>= 8;
729                     size--;
730                 } else {
731                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
732                 }
733             }
734 
735             /* check for complete packet */
736             if (s->rw_offset > 5 &&
737                 (s->loc[locty].sts & TPM_TIS_STS_EXPECT)) {
738                 /* we have a packet length - see if we have all of it */
739                 bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
740 
741                 len = tpm_cmd_get_size(&s->buffer);
742                 if (len > s->rw_offset) {
743                     tpm_tis_sts_set(&s->loc[locty],
744                                     TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
745                 } else {
746                     /* packet complete */
747                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
748                 }
749                 if (need_irq) {
750                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
751                 }
752             }
753         }
754         break;
755     case TPM_TIS_REG_INTERFACE_ID:
756         if (val & TPM_TIS_IFACE_ID_INT_SEL_LOCK) {
757             for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
758                 s->loc[l].iface_id |= TPM_TIS_IFACE_ID_INT_SEL_LOCK;
759             }
760         }
761         break;
762     }
763 }
764 
765 const MemoryRegionOps tpm_tis_memory_ops = {
766     .read = tpm_tis_mmio_read,
767     .write = tpm_tis_mmio_write,
768     .endianness = DEVICE_LITTLE_ENDIAN,
769     .valid = {
770         .min_access_size = 1,
771         .max_access_size = 4,
772     },
773 };
774 
775 /*
776  * Get the TPMVersion of the backend device being used
777  */
778 enum TPMVersion tpm_tis_get_tpm_version(TPMState *s)
779 {
780     if (tpm_backend_had_startup_error(s->be_driver)) {
781         return TPM_VERSION_UNSPEC;
782     }
783 
784     return tpm_backend_get_tpm_version(s->be_driver);
785 }
786 
787 /*
788  * This function is called when the machine starts, resets or due to
789  * S3 resume.
790  */
791 void tpm_tis_reset(TPMState *s)
792 {
793     int c;
794 
795     s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
796     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->be_driver),
797                             TPM_TIS_BUFFER_MAX);
798 
799     if (s->ppi_enabled) {
800         tpm_ppi_reset(&s->ppi);
801     }
802     tpm_backend_reset(s->be_driver);
803 
804     s->active_locty = TPM_TIS_NO_LOCALITY;
805     s->next_locty = TPM_TIS_NO_LOCALITY;
806     s->aborting_locty = TPM_TIS_NO_LOCALITY;
807 
808     for (c = 0; c < TPM_TIS_NUM_LOCALITIES; c++) {
809         s->loc[c].access = TPM_TIS_ACCESS_TPM_REG_VALID_STS;
810         switch (s->be_tpm_version) {
811         case TPM_VERSION_UNSPEC:
812             break;
813         case TPM_VERSION_1_2:
814             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY1_2;
815             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
816             break;
817         case TPM_VERSION_2_0:
818             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY2_0;
819             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0;
820             break;
821         }
822         s->loc[c].inte = TPM_TIS_INT_POLARITY_LOW_LEVEL;
823         s->loc[c].ints = 0;
824         s->loc[c].state = TPM_TIS_STATE_IDLE;
825 
826         s->rw_offset = 0;
827     }
828 
829     if (tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size) < 0) {
830         exit(1);
831     }
832 }
833 
834 /* persistent state handling */
835 
836 int tpm_tis_pre_save(TPMState *s)
837 {
838     uint8_t locty = s->active_locty;
839 
840     trace_tpm_tis_pre_save(locty, s->rw_offset);
841 
842     if (DEBUG_TIS) {
843         tpm_tis_dump_state(s, 0);
844     }
845 
846     /*
847      * Synchronize with backend completion.
848      */
849     tpm_backend_finish_sync(s->be_driver);
850 
851     return 0;
852 }
853 
854 const VMStateDescription vmstate_locty = {
855     .name = "tpm-tis/locty",
856     .version_id = 0,
857     .fields      = (VMStateField[]) {
858         VMSTATE_UINT32(state, TPMLocality),
859         VMSTATE_UINT32(inte, TPMLocality),
860         VMSTATE_UINT32(ints, TPMLocality),
861         VMSTATE_UINT8(access, TPMLocality),
862         VMSTATE_UINT32(sts, TPMLocality),
863         VMSTATE_UINT32(iface_id, TPMLocality),
864         VMSTATE_END_OF_LIST(),
865     }
866 };
867 
868