xref: /qemu/hw/tpm/tpm_tis_common.c (revision cd38cc519b60bbe5dd8d85f6aaa72b2d7902930b)
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 "tpm_ppi.h"
35 #include "trace.h"
36 
37 #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
38 #define TPM_TIS_LOCALITY_SHIFT      12
39 #define TPM_TIS_NO_LOCALITY         0xff
40 
41 #define TPM_TIS_IS_VALID_LOCTY(x)   ((x) < TPM_TIS_NUM_LOCALITIES)
42 
43 #define TPM_TIS_BUFFER_MAX          4096
44 
45 typedef enum {
46     TPM_TIS_STATE_IDLE = 0,
47     TPM_TIS_STATE_READY,
48     TPM_TIS_STATE_COMPLETION,
49     TPM_TIS_STATE_EXECUTION,
50     TPM_TIS_STATE_RECEPTION,
51 } TPMTISState;
52 
53 /* locality data  -- all fields are persisted */
54 typedef struct TPMLocality {
55     TPMTISState state;
56     uint8_t access;
57     uint32_t sts;
58     uint32_t iface_id;
59     uint32_t inte;
60     uint32_t ints;
61 } TPMLocality;
62 
63 typedef struct TPMState {
64     ISADevice busdev;
65     MemoryRegion mmio;
66 
67     unsigned char buffer[TPM_TIS_BUFFER_MAX];
68     uint16_t rw_offset;
69 
70     uint8_t active_locty;
71     uint8_t aborting_locty;
72     uint8_t next_locty;
73 
74     TPMLocality loc[TPM_TIS_NUM_LOCALITIES];
75 
76     qemu_irq irq;
77     uint32_t irq_num;
78 
79     TPMBackendCmd cmd;
80 
81     TPMBackend *be_driver;
82     TPMVersion be_tpm_version;
83 
84     size_t be_buffer_size;
85 
86     bool ppi_enabled;
87     TPMPPI ppi;
88 } TPMState;
89 
90 #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS)
91 
92 #define DEBUG_TIS 0
93 
94 /* local prototypes */
95 
96 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
97                                   unsigned size);
98 
99 /* utility functions */
100 
101 static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
102 {
103     return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
104 }
105 
106 static void tpm_tis_show_buffer(const unsigned char *buffer,
107                                 size_t buffer_size, const char *string)
108 {
109     size_t len, i;
110     char *line_buffer, *p;
111 
112     len = MIN(tpm_cmd_get_size(buffer), buffer_size);
113 
114     /*
115      * allocate enough room for 3 chars per buffer entry plus a
116      * newline after every 16 chars and a final null terminator.
117      */
118     line_buffer = g_malloc(len * 3 + (len / 16) + 1);
119 
120     for (i = 0, p = line_buffer; i < len; i++) {
121         if (i && !(i % 16)) {
122             p += sprintf(p, "\n");
123         }
124         p += sprintf(p, "%.2X ", buffer[i]);
125     }
126     trace_tpm_tis_show_buffer(string, len, line_buffer);
127 
128     g_free(line_buffer);
129 }
130 
131 /*
132  * Set the given flags in the STS register by clearing the register but
133  * preserving the SELFTEST_DONE and TPM_FAMILY_MASK flags and then setting
134  * the new flags.
135  *
136  * The SELFTEST_DONE flag is acquired from the backend that determines it by
137  * peeking into TPM commands.
138  *
139  * A VM suspend/resume will preserve the flag by storing it into the VM
140  * device state, but the backend will not remember it when QEMU is started
141  * again. Therefore, we cache the flag here. Once set, it will not be unset
142  * except by a reset.
143  */
144 static void tpm_tis_sts_set(TPMLocality *l, uint32_t flags)
145 {
146     l->sts &= TPM_TIS_STS_SELFTEST_DONE | TPM_TIS_STS_TPM_FAMILY_MASK;
147     l->sts |= flags;
148 }
149 
150 /*
151  * Send a request to the TPM.
152  */
153 static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
154 {
155     if (trace_event_get_state_backends(TRACE_TPM_TIS_SHOW_BUFFER)) {
156         tpm_tis_show_buffer(s->buffer, s->be_buffer_size, "To TPM");
157     }
158 
159     /*
160      * rw_offset serves as length indicator for length of data;
161      * it's reset when the response comes back
162      */
163     s->loc[locty].state = TPM_TIS_STATE_EXECUTION;
164 
165     s->cmd = (TPMBackendCmd) {
166         .locty = locty,
167         .in = s->buffer,
168         .in_len = s->rw_offset,
169         .out = s->buffer,
170         .out_len = s->be_buffer_size,
171     };
172 
173     tpm_backend_deliver_request(s->be_driver, &s->cmd);
174 }
175 
176 /* raise an interrupt if allowed */
177 static void tpm_tis_raise_irq(TPMState *s, uint8_t locty, uint32_t irqmask)
178 {
179     if (!TPM_TIS_IS_VALID_LOCTY(locty)) {
180         return;
181     }
182 
183     if ((s->loc[locty].inte & TPM_TIS_INT_ENABLED) &&
184         (s->loc[locty].inte & irqmask)) {
185         trace_tpm_tis_raise_irq(irqmask);
186         qemu_irq_raise(s->irq);
187         s->loc[locty].ints |= irqmask;
188     }
189 }
190 
191 static uint32_t tpm_tis_check_request_use_except(TPMState *s, uint8_t locty)
192 {
193     uint8_t l;
194 
195     for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
196         if (l == locty) {
197             continue;
198         }
199         if ((s->loc[l].access & TPM_TIS_ACCESS_REQUEST_USE)) {
200             return 1;
201         }
202     }
203 
204     return 0;
205 }
206 
207 static void tpm_tis_new_active_locality(TPMState *s, uint8_t new_active_locty)
208 {
209     bool change = (s->active_locty != new_active_locty);
210     bool is_seize;
211     uint8_t mask;
212 
213     if (change && TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
214         is_seize = TPM_TIS_IS_VALID_LOCTY(new_active_locty) &&
215                    s->loc[new_active_locty].access & TPM_TIS_ACCESS_SEIZE;
216 
217         if (is_seize) {
218             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY);
219         } else {
220             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY|
221                      TPM_TIS_ACCESS_REQUEST_USE);
222         }
223         /* reset flags on the old active locality */
224         s->loc[s->active_locty].access &= mask;
225 
226         if (is_seize) {
227             s->loc[s->active_locty].access |= TPM_TIS_ACCESS_BEEN_SEIZED;
228         }
229     }
230 
231     s->active_locty = new_active_locty;
232 
233     trace_tpm_tis_new_active_locality(s->active_locty);
234 
235     if (TPM_TIS_IS_VALID_LOCTY(new_active_locty)) {
236         /* set flags on the new active locality */
237         s->loc[new_active_locty].access |= TPM_TIS_ACCESS_ACTIVE_LOCALITY;
238         s->loc[new_active_locty].access &= ~(TPM_TIS_ACCESS_REQUEST_USE |
239                                                TPM_TIS_ACCESS_SEIZE);
240     }
241 
242     if (change) {
243         tpm_tis_raise_irq(s, s->active_locty, TPM_TIS_INT_LOCALITY_CHANGED);
244     }
245 }
246 
247 /* abort -- this function switches the locality */
248 static void tpm_tis_abort(TPMState *s)
249 {
250     s->rw_offset = 0;
251 
252     trace_tpm_tis_abort(s->next_locty);
253 
254     /*
255      * Need to react differently depending on who's aborting now and
256      * which locality will become active afterwards.
257      */
258     if (s->aborting_locty == s->next_locty) {
259         s->loc[s->aborting_locty].state = TPM_TIS_STATE_READY;
260         tpm_tis_sts_set(&s->loc[s->aborting_locty],
261                         TPM_TIS_STS_COMMAND_READY);
262         tpm_tis_raise_irq(s, s->aborting_locty, TPM_TIS_INT_COMMAND_READY);
263     }
264 
265     /* locality after abort is another one than the current one */
266     tpm_tis_new_active_locality(s, s->next_locty);
267 
268     s->next_locty = TPM_TIS_NO_LOCALITY;
269     /* nobody's aborting a command anymore */
270     s->aborting_locty = TPM_TIS_NO_LOCALITY;
271 }
272 
273 /* prepare aborting current command */
274 static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
275 {
276     uint8_t busy_locty;
277 
278     assert(TPM_TIS_IS_VALID_LOCTY(newlocty));
279 
280     s->aborting_locty = locty; /* may also be TPM_TIS_NO_LOCALITY */
281     s->next_locty = newlocty;  /* locality after successful abort */
282 
283     /*
284      * only abort a command using an interrupt if currently executing
285      * a command AND if there's a valid connection to the vTPM.
286      */
287     for (busy_locty = 0; busy_locty < TPM_TIS_NUM_LOCALITIES; busy_locty++) {
288         if (s->loc[busy_locty].state == TPM_TIS_STATE_EXECUTION) {
289             /*
290              * request the backend to cancel. Some backends may not
291              * support it
292              */
293             tpm_backend_cancel_cmd(s->be_driver);
294             return;
295         }
296     }
297 
298     tpm_tis_abort(s);
299 }
300 
301 /*
302  * Callback from the TPM to indicate that the response was received.
303  */
304 static void tpm_tis_request_completed(TPMIf *ti, int ret)
305 {
306     TPMState *s = TPM(ti);
307     uint8_t locty = s->cmd.locty;
308     uint8_t l;
309 
310     assert(TPM_TIS_IS_VALID_LOCTY(locty));
311 
312     if (s->cmd.selftest_done) {
313         for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
314             s->loc[l].sts |= TPM_TIS_STS_SELFTEST_DONE;
315         }
316     }
317 
318     /* FIXME: report error if ret != 0 */
319     tpm_tis_sts_set(&s->loc[locty],
320                     TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
321     s->loc[locty].state = TPM_TIS_STATE_COMPLETION;
322     s->rw_offset = 0;
323 
324     if (trace_event_get_state_backends(TRACE_TPM_TIS_SHOW_BUFFER)) {
325         tpm_tis_show_buffer(s->buffer, s->be_buffer_size, "From TPM");
326     }
327 
328     if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
329         tpm_tis_abort(s);
330     }
331 
332     tpm_tis_raise_irq(s, locty,
333                       TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
334 }
335 
336 /*
337  * Read a byte of response data
338  */
339 static uint32_t tpm_tis_data_read(TPMState *s, uint8_t locty)
340 {
341     uint32_t ret = TPM_TIS_NO_DATA_BYTE;
342     uint16_t len;
343 
344     if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
345         len = MIN(tpm_cmd_get_size(&s->buffer),
346                   s->be_buffer_size);
347 
348         ret = s->buffer[s->rw_offset++];
349         if (s->rw_offset >= len) {
350             /* got last byte */
351             tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
352             tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
353         }
354         trace_tpm_tis_data_read(ret, s->rw_offset - 1);
355     }
356 
357     return ret;
358 }
359 
360 #ifdef DEBUG_TIS
361 static void tpm_tis_dump_state(void *opaque, hwaddr addr)
362 {
363     static const unsigned regs[] = {
364         TPM_TIS_REG_ACCESS,
365         TPM_TIS_REG_INT_ENABLE,
366         TPM_TIS_REG_INT_VECTOR,
367         TPM_TIS_REG_INT_STATUS,
368         TPM_TIS_REG_INTF_CAPABILITY,
369         TPM_TIS_REG_STS,
370         TPM_TIS_REG_DID_VID,
371         TPM_TIS_REG_RID,
372         0xfff};
373     int idx;
374     uint8_t locty = tpm_tis_locality_from_addr(addr);
375     hwaddr base = addr & ~0xfff;
376     TPMState *s = opaque;
377 
378     printf("tpm_tis: active locality      : %d\n"
379            "tpm_tis: state of locality %d : %d\n"
380            "tpm_tis: register dump:\n",
381            s->active_locty,
382            locty, s->loc[locty].state);
383 
384     for (idx = 0; regs[idx] != 0xfff; idx++) {
385         printf("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
386                (int)tpm_tis_mmio_read(opaque, base + regs[idx], 4));
387     }
388 
389     printf("tpm_tis: r/w offset    : %d\n"
390            "tpm_tis: result buffer : ",
391            s->rw_offset);
392     for (idx = 0;
393          idx < MIN(tpm_cmd_get_size(&s->buffer), s->be_buffer_size);
394          idx++) {
395         printf("%c%02x%s",
396                s->rw_offset == idx ? '>' : ' ',
397                s->buffer[idx],
398                ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
399     }
400     printf("\n");
401 }
402 #endif
403 
404 /*
405  * Read a register of the TIS interface
406  * See specs pages 33-63 for description of the registers
407  */
408 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
409                                   unsigned size)
410 {
411     TPMState *s = opaque;
412     uint16_t offset = addr & 0xffc;
413     uint8_t shift = (addr & 0x3) * 8;
414     uint32_t val = 0xffffffff;
415     uint8_t locty = tpm_tis_locality_from_addr(addr);
416     uint32_t avail;
417     uint8_t v;
418 
419     if (tpm_backend_had_startup_error(s->be_driver)) {
420         return 0;
421     }
422 
423     switch (offset) {
424     case TPM_TIS_REG_ACCESS:
425         /* never show the SEIZE flag even though we use it internally */
426         val = s->loc[locty].access & ~TPM_TIS_ACCESS_SEIZE;
427         /* the pending flag is always calculated */
428         if (tpm_tis_check_request_use_except(s, locty)) {
429             val |= TPM_TIS_ACCESS_PENDING_REQUEST;
430         }
431         val |= !tpm_backend_get_tpm_established_flag(s->be_driver);
432         break;
433     case TPM_TIS_REG_INT_ENABLE:
434         val = s->loc[locty].inte;
435         break;
436     case TPM_TIS_REG_INT_VECTOR:
437         val = s->irq_num;
438         break;
439     case TPM_TIS_REG_INT_STATUS:
440         val = s->loc[locty].ints;
441         break;
442     case TPM_TIS_REG_INTF_CAPABILITY:
443         switch (s->be_tpm_version) {
444         case TPM_VERSION_UNSPEC:
445             val = 0;
446             break;
447         case TPM_VERSION_1_2:
448             val = TPM_TIS_CAPABILITIES_SUPPORTED1_3;
449             break;
450         case TPM_VERSION_2_0:
451             val = TPM_TIS_CAPABILITIES_SUPPORTED2_0;
452             break;
453         }
454         break;
455     case TPM_TIS_REG_STS:
456         if (s->active_locty == locty) {
457             if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
458                 val = TPM_TIS_BURST_COUNT(
459                        MIN(tpm_cmd_get_size(&s->buffer),
460                            s->be_buffer_size)
461                        - s->rw_offset) | s->loc[locty].sts;
462             } else {
463                 avail = s->be_buffer_size - s->rw_offset;
464                 /*
465                  * byte-sized reads should not return 0x00 for 0x100
466                  * available bytes.
467                  */
468                 if (size == 1 && avail > 0xff) {
469                     avail = 0xff;
470                 }
471                 val = TPM_TIS_BURST_COUNT(avail) | s->loc[locty].sts;
472             }
473         }
474         break;
475     case TPM_TIS_REG_DATA_FIFO:
476     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
477         if (s->active_locty == locty) {
478             if (size > 4 - (addr & 0x3)) {
479                 /* prevent access beyond FIFO */
480                 size = 4 - (addr & 0x3);
481             }
482             val = 0;
483             shift = 0;
484             while (size > 0) {
485                 switch (s->loc[locty].state) {
486                 case TPM_TIS_STATE_COMPLETION:
487                     v = tpm_tis_data_read(s, locty);
488                     break;
489                 default:
490                     v = TPM_TIS_NO_DATA_BYTE;
491                     break;
492                 }
493                 val |= (v << shift);
494                 shift += 8;
495                 size--;
496             }
497             shift = 0; /* no more adjustments */
498         }
499         break;
500     case TPM_TIS_REG_INTERFACE_ID:
501         val = s->loc[locty].iface_id;
502         break;
503     case TPM_TIS_REG_DID_VID:
504         val = (TPM_TIS_TPM_DID << 16) | TPM_TIS_TPM_VID;
505         break;
506     case TPM_TIS_REG_RID:
507         val = TPM_TIS_TPM_RID;
508         break;
509 #ifdef DEBUG_TIS
510     case TPM_TIS_REG_DEBUG:
511         tpm_tis_dump_state(opaque, addr);
512         break;
513 #endif
514     }
515 
516     if (shift) {
517         val >>= shift;
518     }
519 
520     trace_tpm_tis_mmio_read(size, addr, val);
521 
522     return val;
523 }
524 
525 /*
526  * Write a value to a register of the TIS interface
527  * See specs pages 33-63 for description of the registers
528  */
529 static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
530                                uint64_t val, unsigned size)
531 {
532     TPMState *s = opaque;
533     uint16_t off = addr & 0xffc;
534     uint8_t shift = (addr & 0x3) * 8;
535     uint8_t locty = tpm_tis_locality_from_addr(addr);
536     uint8_t active_locty, l;
537     int c, set_new_locty = 1;
538     uint16_t len;
539     uint32_t mask = (size == 1) ? 0xff : ((size == 2) ? 0xffff : ~0);
540 
541     trace_tpm_tis_mmio_write(size, addr, val);
542 
543     if (locty == 4) {
544         trace_tpm_tis_mmio_write_locty4();
545         return;
546     }
547 
548     if (tpm_backend_had_startup_error(s->be_driver)) {
549         return;
550     }
551 
552     val &= mask;
553 
554     if (shift) {
555         val <<= shift;
556         mask <<= shift;
557     }
558 
559     mask ^= 0xffffffff;
560 
561     switch (off) {
562     case TPM_TIS_REG_ACCESS:
563 
564         if ((val & TPM_TIS_ACCESS_SEIZE)) {
565             val &= ~(TPM_TIS_ACCESS_REQUEST_USE |
566                      TPM_TIS_ACCESS_ACTIVE_LOCALITY);
567         }
568 
569         active_locty = s->active_locty;
570 
571         if ((val & TPM_TIS_ACCESS_ACTIVE_LOCALITY)) {
572             /* give up locality if currently owned */
573             if (s->active_locty == locty) {
574                 trace_tpm_tis_mmio_write_release_locty(locty);
575 
576                 uint8_t newlocty = TPM_TIS_NO_LOCALITY;
577                 /* anybody wants the locality ? */
578                 for (c = TPM_TIS_NUM_LOCALITIES - 1; c >= 0; c--) {
579                     if ((s->loc[c].access & TPM_TIS_ACCESS_REQUEST_USE)) {
580                         trace_tpm_tis_mmio_write_locty_req_use(c);
581                         newlocty = c;
582                         break;
583                     }
584                 }
585                 trace_tpm_tis_mmio_write_next_locty(newlocty);
586 
587                 if (TPM_TIS_IS_VALID_LOCTY(newlocty)) {
588                     set_new_locty = 0;
589                     tpm_tis_prep_abort(s, locty, newlocty);
590                 } else {
591                     active_locty = TPM_TIS_NO_LOCALITY;
592                 }
593             } else {
594                 /* not currently the owner; clear a pending request */
595                 s->loc[locty].access &= ~TPM_TIS_ACCESS_REQUEST_USE;
596             }
597         }
598 
599         if ((val & TPM_TIS_ACCESS_BEEN_SEIZED)) {
600             s->loc[locty].access &= ~TPM_TIS_ACCESS_BEEN_SEIZED;
601         }
602 
603         if ((val & TPM_TIS_ACCESS_SEIZE)) {
604             /*
605              * allow seize if a locality is active and the requesting
606              * locality is higher than the one that's active
607              * OR
608              * allow seize for requesting locality if no locality is
609              * active
610              */
611             while ((TPM_TIS_IS_VALID_LOCTY(s->active_locty) &&
612                     locty > s->active_locty) ||
613                     !TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
614                 bool higher_seize = FALSE;
615 
616                 /* already a pending SEIZE ? */
617                 if ((s->loc[locty].access & TPM_TIS_ACCESS_SEIZE)) {
618                     break;
619                 }
620 
621                 /* check for ongoing seize by a higher locality */
622                 for (l = locty + 1; l < TPM_TIS_NUM_LOCALITIES; l++) {
623                     if ((s->loc[l].access & TPM_TIS_ACCESS_SEIZE)) {
624                         higher_seize = TRUE;
625                         break;
626                     }
627                 }
628 
629                 if (higher_seize) {
630                     break;
631                 }
632 
633                 /* cancel any seize by a lower locality */
634                 for (l = 0; l < locty; l++) {
635                     s->loc[l].access &= ~TPM_TIS_ACCESS_SEIZE;
636                 }
637 
638                 s->loc[locty].access |= TPM_TIS_ACCESS_SEIZE;
639 
640                 trace_tpm_tis_mmio_write_locty_seized(locty, s->active_locty);
641                 trace_tpm_tis_mmio_write_init_abort();
642 
643                 set_new_locty = 0;
644                 tpm_tis_prep_abort(s, s->active_locty, locty);
645                 break;
646             }
647         }
648 
649         if ((val & TPM_TIS_ACCESS_REQUEST_USE)) {
650             if (s->active_locty != locty) {
651                 if (TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
652                     s->loc[locty].access |= TPM_TIS_ACCESS_REQUEST_USE;
653                 } else {
654                     /* no locality active -> make this one active now */
655                     active_locty = locty;
656                 }
657             }
658         }
659 
660         if (set_new_locty) {
661             tpm_tis_new_active_locality(s, active_locty);
662         }
663 
664         break;
665     case TPM_TIS_REG_INT_ENABLE:
666         if (s->active_locty != locty) {
667             break;
668         }
669 
670         s->loc[locty].inte &= mask;
671         s->loc[locty].inte |= (val & (TPM_TIS_INT_ENABLED |
672                                         TPM_TIS_INT_POLARITY_MASK |
673                                         TPM_TIS_INTERRUPTS_SUPPORTED));
674         break;
675     case TPM_TIS_REG_INT_VECTOR:
676         /* hard wired -- ignore */
677         break;
678     case TPM_TIS_REG_INT_STATUS:
679         if (s->active_locty != locty) {
680             break;
681         }
682 
683         /* clearing of interrupt flags */
684         if (((val & TPM_TIS_INTERRUPTS_SUPPORTED)) &&
685             (s->loc[locty].ints & TPM_TIS_INTERRUPTS_SUPPORTED)) {
686             s->loc[locty].ints &= ~val;
687             if (s->loc[locty].ints == 0) {
688                 qemu_irq_lower(s->irq);
689                 trace_tpm_tis_mmio_write_lowering_irq();
690             }
691         }
692         s->loc[locty].ints &= ~(val & TPM_TIS_INTERRUPTS_SUPPORTED);
693         break;
694     case TPM_TIS_REG_STS:
695         if (s->active_locty != locty) {
696             break;
697         }
698 
699         if (s->be_tpm_version == TPM_VERSION_2_0) {
700             /* some flags that are only supported for TPM 2 */
701             if (val & TPM_TIS_STS_COMMAND_CANCEL) {
702                 if (s->loc[locty].state == TPM_TIS_STATE_EXECUTION) {
703                     /*
704                      * request the backend to cancel. Some backends may not
705                      * support it
706                      */
707                     tpm_backend_cancel_cmd(s->be_driver);
708                 }
709             }
710 
711             if (val & TPM_TIS_STS_RESET_ESTABLISHMENT_BIT) {
712                 if (locty == 3 || locty == 4) {
713                     tpm_backend_reset_tpm_established_flag(s->be_driver, locty);
714                 }
715             }
716         }
717 
718         val &= (TPM_TIS_STS_COMMAND_READY | TPM_TIS_STS_TPM_GO |
719                 TPM_TIS_STS_RESPONSE_RETRY);
720 
721         if (val == TPM_TIS_STS_COMMAND_READY) {
722             switch (s->loc[locty].state) {
723 
724             case TPM_TIS_STATE_READY:
725                 s->rw_offset = 0;
726             break;
727 
728             case TPM_TIS_STATE_IDLE:
729                 tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_COMMAND_READY);
730                 s->loc[locty].state = TPM_TIS_STATE_READY;
731                 tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
732             break;
733 
734             case TPM_TIS_STATE_EXECUTION:
735             case TPM_TIS_STATE_RECEPTION:
736                 /* abort currently running command */
737                 trace_tpm_tis_mmio_write_init_abort();
738                 tpm_tis_prep_abort(s, locty, locty);
739             break;
740 
741             case TPM_TIS_STATE_COMPLETION:
742                 s->rw_offset = 0;
743                 /* shortcut to ready state with C/R set */
744                 s->loc[locty].state = TPM_TIS_STATE_READY;
745                 if (!(s->loc[locty].sts & TPM_TIS_STS_COMMAND_READY)) {
746                     tpm_tis_sts_set(&s->loc[locty],
747                                     TPM_TIS_STS_COMMAND_READY);
748                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
749                 }
750                 s->loc[locty].sts &= ~(TPM_TIS_STS_DATA_AVAILABLE);
751             break;
752 
753             }
754         } else if (val == TPM_TIS_STS_TPM_GO) {
755             switch (s->loc[locty].state) {
756             case TPM_TIS_STATE_RECEPTION:
757                 if ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) == 0) {
758                     tpm_tis_tpm_send(s, locty);
759                 }
760                 break;
761             default:
762                 /* ignore */
763                 break;
764             }
765         } else if (val == TPM_TIS_STS_RESPONSE_RETRY) {
766             switch (s->loc[locty].state) {
767             case TPM_TIS_STATE_COMPLETION:
768                 s->rw_offset = 0;
769                 tpm_tis_sts_set(&s->loc[locty],
770                                 TPM_TIS_STS_VALID|
771                                 TPM_TIS_STS_DATA_AVAILABLE);
772                 break;
773             default:
774                 /* ignore */
775                 break;
776             }
777         }
778         break;
779     case TPM_TIS_REG_DATA_FIFO:
780     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
781         /* data fifo */
782         if (s->active_locty != locty) {
783             break;
784         }
785 
786         if (s->loc[locty].state == TPM_TIS_STATE_IDLE ||
787             s->loc[locty].state == TPM_TIS_STATE_EXECUTION ||
788             s->loc[locty].state == TPM_TIS_STATE_COMPLETION) {
789             /* drop the byte */
790         } else {
791             trace_tpm_tis_mmio_write_data2send(val, size);
792             if (s->loc[locty].state == TPM_TIS_STATE_READY) {
793                 s->loc[locty].state = TPM_TIS_STATE_RECEPTION;
794                 tpm_tis_sts_set(&s->loc[locty],
795                                 TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
796             }
797 
798             val >>= shift;
799             if (size > 4 - (addr & 0x3)) {
800                 /* prevent access beyond FIFO */
801                 size = 4 - (addr & 0x3);
802             }
803 
804             while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
805                 if (s->rw_offset < s->be_buffer_size) {
806                     s->buffer[s->rw_offset++] =
807                         (uint8_t)val;
808                     val >>= 8;
809                     size--;
810                 } else {
811                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
812                 }
813             }
814 
815             /* check for complete packet */
816             if (s->rw_offset > 5 &&
817                 (s->loc[locty].sts & TPM_TIS_STS_EXPECT)) {
818                 /* we have a packet length - see if we have all of it */
819                 bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
820 
821                 len = tpm_cmd_get_size(&s->buffer);
822                 if (len > s->rw_offset) {
823                     tpm_tis_sts_set(&s->loc[locty],
824                                     TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
825                 } else {
826                     /* packet complete */
827                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
828                 }
829                 if (need_irq) {
830                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
831                 }
832             }
833         }
834         break;
835     case TPM_TIS_REG_INTERFACE_ID:
836         if (val & TPM_TIS_IFACE_ID_INT_SEL_LOCK) {
837             for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
838                 s->loc[l].iface_id |= TPM_TIS_IFACE_ID_INT_SEL_LOCK;
839             }
840         }
841         break;
842     }
843 }
844 
845 static const MemoryRegionOps tpm_tis_memory_ops = {
846     .read = tpm_tis_mmio_read,
847     .write = tpm_tis_mmio_write,
848     .endianness = DEVICE_LITTLE_ENDIAN,
849     .valid = {
850         .min_access_size = 1,
851         .max_access_size = 4,
852     },
853 };
854 
855 /*
856  * Get the TPMVersion of the backend device being used
857  */
858 static enum TPMVersion tpm_tis_get_tpm_version(TPMIf *ti)
859 {
860     TPMState *s = TPM(ti);
861 
862     if (tpm_backend_had_startup_error(s->be_driver)) {
863         return TPM_VERSION_UNSPEC;
864     }
865 
866     return tpm_backend_get_tpm_version(s->be_driver);
867 }
868 
869 /*
870  * This function is called when the machine starts, resets or due to
871  * S3 resume.
872  */
873 static void tpm_tis_reset(DeviceState *dev)
874 {
875     TPMState *s = TPM(dev);
876     int c;
877 
878     s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
879     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->be_driver),
880                             TPM_TIS_BUFFER_MAX);
881 
882     if (s->ppi_enabled) {
883         tpm_ppi_reset(&s->ppi);
884     }
885     tpm_backend_reset(s->be_driver);
886 
887     s->active_locty = TPM_TIS_NO_LOCALITY;
888     s->next_locty = TPM_TIS_NO_LOCALITY;
889     s->aborting_locty = TPM_TIS_NO_LOCALITY;
890 
891     for (c = 0; c < TPM_TIS_NUM_LOCALITIES; c++) {
892         s->loc[c].access = TPM_TIS_ACCESS_TPM_REG_VALID_STS;
893         switch (s->be_tpm_version) {
894         case TPM_VERSION_UNSPEC:
895             break;
896         case TPM_VERSION_1_2:
897             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY1_2;
898             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
899             break;
900         case TPM_VERSION_2_0:
901             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY2_0;
902             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0;
903             break;
904         }
905         s->loc[c].inte = TPM_TIS_INT_POLARITY_LOW_LEVEL;
906         s->loc[c].ints = 0;
907         s->loc[c].state = TPM_TIS_STATE_IDLE;
908 
909         s->rw_offset = 0;
910     }
911 
912     tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size);
913 }
914 
915 /* persistent state handling */
916 
917 static int tpm_tis_pre_save(void *opaque)
918 {
919     TPMState *s = opaque;
920     uint8_t locty = s->active_locty;
921 
922     trace_tpm_tis_pre_save(locty, s->rw_offset);
923 
924     if (DEBUG_TIS) {
925         tpm_tis_dump_state(opaque, 0);
926     }
927 
928     /*
929      * Synchronize with backend completion.
930      */
931     tpm_backend_finish_sync(s->be_driver);
932 
933     return 0;
934 }
935 
936 static const VMStateDescription vmstate_locty = {
937     .name = "tpm-tis/locty",
938     .version_id = 0,
939     .fields      = (VMStateField[]) {
940         VMSTATE_UINT32(state, TPMLocality),
941         VMSTATE_UINT32(inte, TPMLocality),
942         VMSTATE_UINT32(ints, TPMLocality),
943         VMSTATE_UINT8(access, TPMLocality),
944         VMSTATE_UINT32(sts, TPMLocality),
945         VMSTATE_UINT32(iface_id, TPMLocality),
946         VMSTATE_END_OF_LIST(),
947     }
948 };
949 
950 static const VMStateDescription vmstate_tpm_tis = {
951     .name = "tpm-tis",
952     .version_id = 0,
953     .pre_save  = tpm_tis_pre_save,
954     .fields = (VMStateField[]) {
955         VMSTATE_BUFFER(buffer, TPMState),
956         VMSTATE_UINT16(rw_offset, TPMState),
957         VMSTATE_UINT8(active_locty, TPMState),
958         VMSTATE_UINT8(aborting_locty, TPMState),
959         VMSTATE_UINT8(next_locty, TPMState),
960 
961         VMSTATE_STRUCT_ARRAY(loc, TPMState, TPM_TIS_NUM_LOCALITIES, 0,
962                              vmstate_locty, TPMLocality),
963 
964         VMSTATE_END_OF_LIST()
965     }
966 };
967 
968 static Property tpm_tis_properties[] = {
969     DEFINE_PROP_UINT32("irq", TPMState, irq_num, TPM_TIS_IRQ),
970     DEFINE_PROP_TPMBE("tpmdev", TPMState, be_driver),
971     DEFINE_PROP_BOOL("ppi", TPMState, ppi_enabled, true),
972     DEFINE_PROP_END_OF_LIST(),
973 };
974 
975 static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
976 {
977     TPMState *s = TPM(dev);
978 
979     if (!tpm_find()) {
980         error_setg(errp, "at most one TPM device is permitted");
981         return;
982     }
983 
984     if (!s->be_driver) {
985         error_setg(errp, "'tpmdev' property is required");
986         return;
987     }
988     if (s->irq_num > 15) {
989         error_setg(errp, "IRQ %d is outside valid range of 0 to 15",
990                    s->irq_num);
991         return;
992     }
993 
994     isa_init_irq(&s->busdev, &s->irq, s->irq_num);
995 
996     memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
997                                 TPM_TIS_ADDR_BASE, &s->mmio);
998 
999     if (s->ppi_enabled) {
1000         tpm_ppi_init(&s->ppi, isa_address_space(ISA_DEVICE(dev)),
1001                      TPM_PPI_ADDR_BASE, OBJECT(s));
1002     }
1003 }
1004 
1005 static void tpm_tis_initfn(Object *obj)
1006 {
1007     TPMState *s = TPM(obj);
1008 
1009     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_tis_memory_ops,
1010                           s, "tpm-tis-mmio",
1011                           TPM_TIS_NUM_LOCALITIES << TPM_TIS_LOCALITY_SHIFT);
1012 }
1013 
1014 static void tpm_tis_class_init(ObjectClass *klass, void *data)
1015 {
1016     DeviceClass *dc = DEVICE_CLASS(klass);
1017     TPMIfClass *tc = TPM_IF_CLASS(klass);
1018 
1019     dc->realize = tpm_tis_realizefn;
1020     dc->props = tpm_tis_properties;
1021     dc->reset = tpm_tis_reset;
1022     dc->vmsd  = &vmstate_tpm_tis;
1023     tc->model = TPM_MODEL_TPM_TIS;
1024     tc->get_version = tpm_tis_get_tpm_version;
1025     tc->request_completed = tpm_tis_request_completed;
1026 }
1027 
1028 static const TypeInfo tpm_tis_info = {
1029     .name = TYPE_TPM_TIS,
1030     .parent = TYPE_ISA_DEVICE,
1031     .instance_size = sizeof(TPMState),
1032     .instance_init = tpm_tis_initfn,
1033     .class_init  = tpm_tis_class_init,
1034     .interfaces = (InterfaceInfo[]) {
1035         { TYPE_TPM_IF },
1036         { }
1037     }
1038 };
1039 
1040 static void tpm_tis_register(void)
1041 {
1042     type_register_static(&tpm_tis_info);
1043 }
1044 
1045 type_init(tpm_tis_register)
1046