xref: /qemu/hw/tpm/tpm_tis_common.c (revision ca75c421731d59b4a4b64d094cf2c747896c6922)
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/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 "tpm_int.h"
37 #include "tpm_util.h"
38 #include "tpm_ppi.h"
39 #include "trace.h"
40 
41 #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
42 #define TPM_TIS_LOCALITY_SHIFT      12
43 #define TPM_TIS_NO_LOCALITY         0xff
44 
45 #define TPM_TIS_IS_VALID_LOCTY(x)   ((x) < TPM_TIS_NUM_LOCALITIES)
46 
47 #define TPM_TIS_BUFFER_MAX          4096
48 
49 typedef enum {
50     TPM_TIS_STATE_IDLE = 0,
51     TPM_TIS_STATE_READY,
52     TPM_TIS_STATE_COMPLETION,
53     TPM_TIS_STATE_EXECUTION,
54     TPM_TIS_STATE_RECEPTION,
55 } TPMTISState;
56 
57 /* locality data  -- all fields are persisted */
58 typedef struct TPMLocality {
59     TPMTISState state;
60     uint8_t access;
61     uint32_t sts;
62     uint32_t iface_id;
63     uint32_t inte;
64     uint32_t ints;
65 } TPMLocality;
66 
67 typedef struct TPMState {
68     MemoryRegion mmio;
69 
70     unsigned char buffer[TPM_TIS_BUFFER_MAX];
71     uint16_t rw_offset;
72 
73     uint8_t active_locty;
74     uint8_t aborting_locty;
75     uint8_t next_locty;
76 
77     TPMLocality loc[TPM_TIS_NUM_LOCALITIES];
78 
79     qemu_irq irq;
80     uint32_t irq_num;
81 
82     TPMBackendCmd cmd;
83 
84     TPMBackend *be_driver;
85     TPMVersion be_tpm_version;
86 
87     size_t be_buffer_size;
88 
89     bool ppi_enabled;
90     TPMPPI ppi;
91 } TPMState;
92 
93 typedef struct TPMStateISA {
94     /*< private >*/
95     ISADevice parent_obj;
96 
97     /*< public >*/
98     TPMState state; /* not a QOM object */
99 } TPMStateISA;
100 
101 #define TPM_TIS_ISA(obj) OBJECT_CHECK(TPMStateISA, (obj), TYPE_TPM_TIS_ISA)
102 
103 #define DEBUG_TIS 0
104 
105 /* local prototypes */
106 
107 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
108                                   unsigned size);
109 
110 /* utility functions */
111 
112 static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
113 {
114     return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
115 }
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 (trace_event_get_state_backends(TRACE_TPM_UTIL_SHOW_BUFFER)) {
143         tpm_util_show_buffer(s->buffer, s->be_buffer_size, "To TPM");
144     }
145 
146     /*
147      * rw_offset serves as length indicator for length of data;
148      * it's reset when the response comes back
149      */
150     s->loc[locty].state = TPM_TIS_STATE_EXECUTION;
151 
152     s->cmd = (TPMBackendCmd) {
153         .locty = locty,
154         .in = s->buffer,
155         .in_len = s->rw_offset,
156         .out = s->buffer,
157         .out_len = s->be_buffer_size,
158     };
159 
160     tpm_backend_deliver_request(s->be_driver, &s->cmd);
161 }
162 
163 /* raise an interrupt if allowed */
164 static void tpm_tis_raise_irq(TPMState *s, uint8_t locty, uint32_t irqmask)
165 {
166     if (!TPM_TIS_IS_VALID_LOCTY(locty)) {
167         return;
168     }
169 
170     if ((s->loc[locty].inte & TPM_TIS_INT_ENABLED) &&
171         (s->loc[locty].inte & irqmask)) {
172         trace_tpm_tis_raise_irq(irqmask);
173         qemu_irq_raise(s->irq);
174         s->loc[locty].ints |= irqmask;
175     }
176 }
177 
178 static uint32_t tpm_tis_check_request_use_except(TPMState *s, uint8_t locty)
179 {
180     uint8_t l;
181 
182     for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
183         if (l == locty) {
184             continue;
185         }
186         if ((s->loc[l].access & TPM_TIS_ACCESS_REQUEST_USE)) {
187             return 1;
188         }
189     }
190 
191     return 0;
192 }
193 
194 static void tpm_tis_new_active_locality(TPMState *s, uint8_t new_active_locty)
195 {
196     bool change = (s->active_locty != new_active_locty);
197     bool is_seize;
198     uint8_t mask;
199 
200     if (change && TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
201         is_seize = TPM_TIS_IS_VALID_LOCTY(new_active_locty) &&
202                    s->loc[new_active_locty].access & TPM_TIS_ACCESS_SEIZE;
203 
204         if (is_seize) {
205             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY);
206         } else {
207             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY|
208                      TPM_TIS_ACCESS_REQUEST_USE);
209         }
210         /* reset flags on the old active locality */
211         s->loc[s->active_locty].access &= mask;
212 
213         if (is_seize) {
214             s->loc[s->active_locty].access |= TPM_TIS_ACCESS_BEEN_SEIZED;
215         }
216     }
217 
218     s->active_locty = new_active_locty;
219 
220     trace_tpm_tis_new_active_locality(s->active_locty);
221 
222     if (TPM_TIS_IS_VALID_LOCTY(new_active_locty)) {
223         /* set flags on the new active locality */
224         s->loc[new_active_locty].access |= TPM_TIS_ACCESS_ACTIVE_LOCALITY;
225         s->loc[new_active_locty].access &= ~(TPM_TIS_ACCESS_REQUEST_USE |
226                                                TPM_TIS_ACCESS_SEIZE);
227     }
228 
229     if (change) {
230         tpm_tis_raise_irq(s, s->active_locty, TPM_TIS_INT_LOCALITY_CHANGED);
231     }
232 }
233 
234 /* abort -- this function switches the locality */
235 static void tpm_tis_abort(TPMState *s)
236 {
237     s->rw_offset = 0;
238 
239     trace_tpm_tis_abort(s->next_locty);
240 
241     /*
242      * Need to react differently depending on who's aborting now and
243      * which locality will become active afterwards.
244      */
245     if (s->aborting_locty == s->next_locty) {
246         s->loc[s->aborting_locty].state = TPM_TIS_STATE_READY;
247         tpm_tis_sts_set(&s->loc[s->aborting_locty],
248                         TPM_TIS_STS_COMMAND_READY);
249         tpm_tis_raise_irq(s, s->aborting_locty, TPM_TIS_INT_COMMAND_READY);
250     }
251 
252     /* locality after abort is another one than the current one */
253     tpm_tis_new_active_locality(s, s->next_locty);
254 
255     s->next_locty = TPM_TIS_NO_LOCALITY;
256     /* nobody's aborting a command anymore */
257     s->aborting_locty = TPM_TIS_NO_LOCALITY;
258 }
259 
260 /* prepare aborting current command */
261 static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
262 {
263     uint8_t busy_locty;
264 
265     assert(TPM_TIS_IS_VALID_LOCTY(newlocty));
266 
267     s->aborting_locty = locty; /* may also be TPM_TIS_NO_LOCALITY */
268     s->next_locty = newlocty;  /* locality after successful abort */
269 
270     /*
271      * only abort a command using an interrupt if currently executing
272      * a command AND if there's a valid connection to the vTPM.
273      */
274     for (busy_locty = 0; busy_locty < TPM_TIS_NUM_LOCALITIES; busy_locty++) {
275         if (s->loc[busy_locty].state == TPM_TIS_STATE_EXECUTION) {
276             /*
277              * request the backend to cancel. Some backends may not
278              * support it
279              */
280             tpm_backend_cancel_cmd(s->be_driver);
281             return;
282         }
283     }
284 
285     tpm_tis_abort(s);
286 }
287 
288 /*
289  * Callback from the TPM to indicate that the response was received.
290  */
291 static void tpm_tis_request_completed(TPMState *s, int ret)
292 {
293     uint8_t locty = s->cmd.locty;
294     uint8_t l;
295 
296     assert(TPM_TIS_IS_VALID_LOCTY(locty));
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 (trace_event_get_state_backends(TRACE_TPM_UTIL_SHOW_BUFFER)) {
311         tpm_util_show_buffer(s->buffer, s->be_buffer_size, "From TPM");
312     }
313 
314     if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
315         tpm_tis_abort(s);
316     }
317 
318     tpm_tis_raise_irq(s, locty,
319                       TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
320 }
321 
322 /*
323  * Read a byte of response data
324  */
325 static uint32_t tpm_tis_data_read(TPMState *s, uint8_t locty)
326 {
327     uint32_t ret = TPM_TIS_NO_DATA_BYTE;
328     uint16_t len;
329 
330     if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
331         len = MIN(tpm_cmd_get_size(&s->buffer),
332                   s->be_buffer_size);
333 
334         ret = s->buffer[s->rw_offset++];
335         if (s->rw_offset >= len) {
336             /* got last byte */
337             tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
338             tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
339         }
340         trace_tpm_tis_data_read(ret, s->rw_offset - 1);
341     }
342 
343     return ret;
344 }
345 
346 #ifdef DEBUG_TIS
347 static void tpm_tis_dump_state(TPMState *s, hwaddr addr)
348 {
349     static const unsigned regs[] = {
350         TPM_TIS_REG_ACCESS,
351         TPM_TIS_REG_INT_ENABLE,
352         TPM_TIS_REG_INT_VECTOR,
353         TPM_TIS_REG_INT_STATUS,
354         TPM_TIS_REG_INTF_CAPABILITY,
355         TPM_TIS_REG_STS,
356         TPM_TIS_REG_DID_VID,
357         TPM_TIS_REG_RID,
358         0xfff};
359     int idx;
360     uint8_t locty = tpm_tis_locality_from_addr(addr);
361     hwaddr base = addr & ~0xfff;
362 
363     printf("tpm_tis: active locality      : %d\n"
364            "tpm_tis: state of locality %d : %d\n"
365            "tpm_tis: register dump:\n",
366            s->active_locty,
367            locty, s->loc[locty].state);
368 
369     for (idx = 0; regs[idx] != 0xfff; idx++) {
370         printf("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
371                (int)tpm_tis_mmio_read(s, base + regs[idx], 4));
372     }
373 
374     printf("tpm_tis: r/w offset    : %d\n"
375            "tpm_tis: result buffer : ",
376            s->rw_offset);
377     for (idx = 0;
378          idx < MIN(tpm_cmd_get_size(&s->buffer), s->be_buffer_size);
379          idx++) {
380         printf("%c%02x%s",
381                s->rw_offset == idx ? '>' : ' ',
382                s->buffer[idx],
383                ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
384     }
385     printf("\n");
386 }
387 #endif
388 
389 /*
390  * Read a register of the TIS interface
391  * See specs pages 33-63 for description of the registers
392  */
393 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
394                                   unsigned size)
395 {
396     TPMState *s = opaque;
397     uint16_t offset = addr & 0xffc;
398     uint8_t shift = (addr & 0x3) * 8;
399     uint32_t val = 0xffffffff;
400     uint8_t locty = tpm_tis_locality_from_addr(addr);
401     uint32_t avail;
402     uint8_t v;
403 
404     if (tpm_backend_had_startup_error(s->be_driver)) {
405         return 0;
406     }
407 
408     switch (offset) {
409     case TPM_TIS_REG_ACCESS:
410         /* never show the SEIZE flag even though we use it internally */
411         val = s->loc[locty].access & ~TPM_TIS_ACCESS_SEIZE;
412         /* the pending flag is always calculated */
413         if (tpm_tis_check_request_use_except(s, locty)) {
414             val |= TPM_TIS_ACCESS_PENDING_REQUEST;
415         }
416         val |= !tpm_backend_get_tpm_established_flag(s->be_driver);
417         break;
418     case TPM_TIS_REG_INT_ENABLE:
419         val = s->loc[locty].inte;
420         break;
421     case TPM_TIS_REG_INT_VECTOR:
422         val = s->irq_num;
423         break;
424     case TPM_TIS_REG_INT_STATUS:
425         val = s->loc[locty].ints;
426         break;
427     case TPM_TIS_REG_INTF_CAPABILITY:
428         switch (s->be_tpm_version) {
429         case TPM_VERSION_UNSPEC:
430             val = 0;
431             break;
432         case TPM_VERSION_1_2:
433             val = TPM_TIS_CAPABILITIES_SUPPORTED1_3;
434             break;
435         case TPM_VERSION_2_0:
436             val = TPM_TIS_CAPABILITIES_SUPPORTED2_0;
437             break;
438         }
439         break;
440     case TPM_TIS_REG_STS:
441         if (s->active_locty == locty) {
442             if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
443                 val = TPM_TIS_BURST_COUNT(
444                        MIN(tpm_cmd_get_size(&s->buffer),
445                            s->be_buffer_size)
446                        - s->rw_offset) | s->loc[locty].sts;
447             } else {
448                 avail = s->be_buffer_size - s->rw_offset;
449                 /*
450                  * byte-sized reads should not return 0x00 for 0x100
451                  * available bytes.
452                  */
453                 if (size == 1 && avail > 0xff) {
454                     avail = 0xff;
455                 }
456                 val = TPM_TIS_BURST_COUNT(avail) | s->loc[locty].sts;
457             }
458         }
459         break;
460     case TPM_TIS_REG_DATA_FIFO:
461     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
462         if (s->active_locty == locty) {
463             if (size > 4 - (addr & 0x3)) {
464                 /* prevent access beyond FIFO */
465                 size = 4 - (addr & 0x3);
466             }
467             val = 0;
468             shift = 0;
469             while (size > 0) {
470                 switch (s->loc[locty].state) {
471                 case TPM_TIS_STATE_COMPLETION:
472                     v = tpm_tis_data_read(s, locty);
473                     break;
474                 default:
475                     v = TPM_TIS_NO_DATA_BYTE;
476                     break;
477                 }
478                 val |= (v << shift);
479                 shift += 8;
480                 size--;
481             }
482             shift = 0; /* no more adjustments */
483         }
484         break;
485     case TPM_TIS_REG_INTERFACE_ID:
486         val = s->loc[locty].iface_id;
487         break;
488     case TPM_TIS_REG_DID_VID:
489         val = (TPM_TIS_TPM_DID << 16) | TPM_TIS_TPM_VID;
490         break;
491     case TPM_TIS_REG_RID:
492         val = TPM_TIS_TPM_RID;
493         break;
494 #ifdef DEBUG_TIS
495     case TPM_TIS_REG_DEBUG:
496         tpm_tis_dump_state(s, addr);
497         break;
498 #endif
499     }
500 
501     if (shift) {
502         val >>= shift;
503     }
504 
505     trace_tpm_tis_mmio_read(size, addr, val);
506 
507     return val;
508 }
509 
510 /*
511  * Write a value to a register of the TIS interface
512  * See specs pages 33-63 for description of the registers
513  */
514 static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
515                                uint64_t val, unsigned size)
516 {
517     TPMState *s = opaque;
518     uint16_t off = addr & 0xffc;
519     uint8_t shift = (addr & 0x3) * 8;
520     uint8_t locty = tpm_tis_locality_from_addr(addr);
521     uint8_t active_locty, l;
522     int c, set_new_locty = 1;
523     uint16_t len;
524     uint32_t mask = (size == 1) ? 0xff : ((size == 2) ? 0xffff : ~0);
525 
526     trace_tpm_tis_mmio_write(size, addr, val);
527 
528     if (locty == 4) {
529         trace_tpm_tis_mmio_write_locty4();
530         return;
531     }
532 
533     if (tpm_backend_had_startup_error(s->be_driver)) {
534         return;
535     }
536 
537     val &= mask;
538 
539     if (shift) {
540         val <<= shift;
541         mask <<= shift;
542     }
543 
544     mask ^= 0xffffffff;
545 
546     switch (off) {
547     case TPM_TIS_REG_ACCESS:
548 
549         if ((val & TPM_TIS_ACCESS_SEIZE)) {
550             val &= ~(TPM_TIS_ACCESS_REQUEST_USE |
551                      TPM_TIS_ACCESS_ACTIVE_LOCALITY);
552         }
553 
554         active_locty = s->active_locty;
555 
556         if ((val & TPM_TIS_ACCESS_ACTIVE_LOCALITY)) {
557             /* give up locality if currently owned */
558             if (s->active_locty == locty) {
559                 trace_tpm_tis_mmio_write_release_locty(locty);
560 
561                 uint8_t newlocty = TPM_TIS_NO_LOCALITY;
562                 /* anybody wants the locality ? */
563                 for (c = TPM_TIS_NUM_LOCALITIES - 1; c >= 0; c--) {
564                     if ((s->loc[c].access & TPM_TIS_ACCESS_REQUEST_USE)) {
565                         trace_tpm_tis_mmio_write_locty_req_use(c);
566                         newlocty = c;
567                         break;
568                     }
569                 }
570                 trace_tpm_tis_mmio_write_next_locty(newlocty);
571 
572                 if (TPM_TIS_IS_VALID_LOCTY(newlocty)) {
573                     set_new_locty = 0;
574                     tpm_tis_prep_abort(s, locty, newlocty);
575                 } else {
576                     active_locty = TPM_TIS_NO_LOCALITY;
577                 }
578             } else {
579                 /* not currently the owner; clear a pending request */
580                 s->loc[locty].access &= ~TPM_TIS_ACCESS_REQUEST_USE;
581             }
582         }
583 
584         if ((val & TPM_TIS_ACCESS_BEEN_SEIZED)) {
585             s->loc[locty].access &= ~TPM_TIS_ACCESS_BEEN_SEIZED;
586         }
587 
588         if ((val & TPM_TIS_ACCESS_SEIZE)) {
589             /*
590              * allow seize if a locality is active and the requesting
591              * locality is higher than the one that's active
592              * OR
593              * allow seize for requesting locality if no locality is
594              * active
595              */
596             while ((TPM_TIS_IS_VALID_LOCTY(s->active_locty) &&
597                     locty > s->active_locty) ||
598                     !TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
599                 bool higher_seize = FALSE;
600 
601                 /* already a pending SEIZE ? */
602                 if ((s->loc[locty].access & TPM_TIS_ACCESS_SEIZE)) {
603                     break;
604                 }
605 
606                 /* check for ongoing seize by a higher locality */
607                 for (l = locty + 1; l < TPM_TIS_NUM_LOCALITIES; l++) {
608                     if ((s->loc[l].access & TPM_TIS_ACCESS_SEIZE)) {
609                         higher_seize = TRUE;
610                         break;
611                     }
612                 }
613 
614                 if (higher_seize) {
615                     break;
616                 }
617 
618                 /* cancel any seize by a lower locality */
619                 for (l = 0; l < locty; l++) {
620                     s->loc[l].access &= ~TPM_TIS_ACCESS_SEIZE;
621                 }
622 
623                 s->loc[locty].access |= TPM_TIS_ACCESS_SEIZE;
624 
625                 trace_tpm_tis_mmio_write_locty_seized(locty, s->active_locty);
626                 trace_tpm_tis_mmio_write_init_abort();
627 
628                 set_new_locty = 0;
629                 tpm_tis_prep_abort(s, s->active_locty, locty);
630                 break;
631             }
632         }
633 
634         if ((val & TPM_TIS_ACCESS_REQUEST_USE)) {
635             if (s->active_locty != locty) {
636                 if (TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
637                     s->loc[locty].access |= TPM_TIS_ACCESS_REQUEST_USE;
638                 } else {
639                     /* no locality active -> make this one active now */
640                     active_locty = locty;
641                 }
642             }
643         }
644 
645         if (set_new_locty) {
646             tpm_tis_new_active_locality(s, active_locty);
647         }
648 
649         break;
650     case TPM_TIS_REG_INT_ENABLE:
651         if (s->active_locty != locty) {
652             break;
653         }
654 
655         s->loc[locty].inte &= mask;
656         s->loc[locty].inte |= (val & (TPM_TIS_INT_ENABLED |
657                                         TPM_TIS_INT_POLARITY_MASK |
658                                         TPM_TIS_INTERRUPTS_SUPPORTED));
659         break;
660     case TPM_TIS_REG_INT_VECTOR:
661         /* hard wired -- ignore */
662         break;
663     case TPM_TIS_REG_INT_STATUS:
664         if (s->active_locty != locty) {
665             break;
666         }
667 
668         /* clearing of interrupt flags */
669         if (((val & TPM_TIS_INTERRUPTS_SUPPORTED)) &&
670             (s->loc[locty].ints & TPM_TIS_INTERRUPTS_SUPPORTED)) {
671             s->loc[locty].ints &= ~val;
672             if (s->loc[locty].ints == 0) {
673                 qemu_irq_lower(s->irq);
674                 trace_tpm_tis_mmio_write_lowering_irq();
675             }
676         }
677         s->loc[locty].ints &= ~(val & TPM_TIS_INTERRUPTS_SUPPORTED);
678         break;
679     case TPM_TIS_REG_STS:
680         if (s->active_locty != locty) {
681             break;
682         }
683 
684         if (s->be_tpm_version == TPM_VERSION_2_0) {
685             /* some flags that are only supported for TPM 2 */
686             if (val & TPM_TIS_STS_COMMAND_CANCEL) {
687                 if (s->loc[locty].state == TPM_TIS_STATE_EXECUTION) {
688                     /*
689                      * request the backend to cancel. Some backends may not
690                      * support it
691                      */
692                     tpm_backend_cancel_cmd(s->be_driver);
693                 }
694             }
695 
696             if (val & TPM_TIS_STS_RESET_ESTABLISHMENT_BIT) {
697                 if (locty == 3 || locty == 4) {
698                     tpm_backend_reset_tpm_established_flag(s->be_driver, locty);
699                 }
700             }
701         }
702 
703         val &= (TPM_TIS_STS_COMMAND_READY | TPM_TIS_STS_TPM_GO |
704                 TPM_TIS_STS_RESPONSE_RETRY);
705 
706         if (val == TPM_TIS_STS_COMMAND_READY) {
707             switch (s->loc[locty].state) {
708 
709             case TPM_TIS_STATE_READY:
710                 s->rw_offset = 0;
711             break;
712 
713             case TPM_TIS_STATE_IDLE:
714                 tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_COMMAND_READY);
715                 s->loc[locty].state = TPM_TIS_STATE_READY;
716                 tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
717             break;
718 
719             case TPM_TIS_STATE_EXECUTION:
720             case TPM_TIS_STATE_RECEPTION:
721                 /* abort currently running command */
722                 trace_tpm_tis_mmio_write_init_abort();
723                 tpm_tis_prep_abort(s, locty, locty);
724             break;
725 
726             case TPM_TIS_STATE_COMPLETION:
727                 s->rw_offset = 0;
728                 /* shortcut to ready state with C/R set */
729                 s->loc[locty].state = TPM_TIS_STATE_READY;
730                 if (!(s->loc[locty].sts & TPM_TIS_STS_COMMAND_READY)) {
731                     tpm_tis_sts_set(&s->loc[locty],
732                                     TPM_TIS_STS_COMMAND_READY);
733                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
734                 }
735                 s->loc[locty].sts &= ~(TPM_TIS_STS_DATA_AVAILABLE);
736             break;
737 
738             }
739         } else if (val == TPM_TIS_STS_TPM_GO) {
740             switch (s->loc[locty].state) {
741             case TPM_TIS_STATE_RECEPTION:
742                 if ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) == 0) {
743                     tpm_tis_tpm_send(s, locty);
744                 }
745                 break;
746             default:
747                 /* ignore */
748                 break;
749             }
750         } else if (val == TPM_TIS_STS_RESPONSE_RETRY) {
751             switch (s->loc[locty].state) {
752             case TPM_TIS_STATE_COMPLETION:
753                 s->rw_offset = 0;
754                 tpm_tis_sts_set(&s->loc[locty],
755                                 TPM_TIS_STS_VALID|
756                                 TPM_TIS_STS_DATA_AVAILABLE);
757                 break;
758             default:
759                 /* ignore */
760                 break;
761             }
762         }
763         break;
764     case TPM_TIS_REG_DATA_FIFO:
765     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
766         /* data fifo */
767         if (s->active_locty != locty) {
768             break;
769         }
770 
771         if (s->loc[locty].state == TPM_TIS_STATE_IDLE ||
772             s->loc[locty].state == TPM_TIS_STATE_EXECUTION ||
773             s->loc[locty].state == TPM_TIS_STATE_COMPLETION) {
774             /* drop the byte */
775         } else {
776             trace_tpm_tis_mmio_write_data2send(val, size);
777             if (s->loc[locty].state == TPM_TIS_STATE_READY) {
778                 s->loc[locty].state = TPM_TIS_STATE_RECEPTION;
779                 tpm_tis_sts_set(&s->loc[locty],
780                                 TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
781             }
782 
783             val >>= shift;
784             if (size > 4 - (addr & 0x3)) {
785                 /* prevent access beyond FIFO */
786                 size = 4 - (addr & 0x3);
787             }
788 
789             while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
790                 if (s->rw_offset < s->be_buffer_size) {
791                     s->buffer[s->rw_offset++] =
792                         (uint8_t)val;
793                     val >>= 8;
794                     size--;
795                 } else {
796                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
797                 }
798             }
799 
800             /* check for complete packet */
801             if (s->rw_offset > 5 &&
802                 (s->loc[locty].sts & TPM_TIS_STS_EXPECT)) {
803                 /* we have a packet length - see if we have all of it */
804                 bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
805 
806                 len = tpm_cmd_get_size(&s->buffer);
807                 if (len > s->rw_offset) {
808                     tpm_tis_sts_set(&s->loc[locty],
809                                     TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
810                 } else {
811                     /* packet complete */
812                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
813                 }
814                 if (need_irq) {
815                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
816                 }
817             }
818         }
819         break;
820     case TPM_TIS_REG_INTERFACE_ID:
821         if (val & TPM_TIS_IFACE_ID_INT_SEL_LOCK) {
822             for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
823                 s->loc[l].iface_id |= TPM_TIS_IFACE_ID_INT_SEL_LOCK;
824             }
825         }
826         break;
827     }
828 }
829 
830 static const MemoryRegionOps tpm_tis_memory_ops = {
831     .read = tpm_tis_mmio_read,
832     .write = tpm_tis_mmio_write,
833     .endianness = DEVICE_LITTLE_ENDIAN,
834     .valid = {
835         .min_access_size = 1,
836         .max_access_size = 4,
837     },
838 };
839 
840 /*
841  * Get the TPMVersion of the backend device being used
842  */
843 static enum TPMVersion tpm_tis_get_tpm_version(TPMState *s)
844 {
845     if (tpm_backend_had_startup_error(s->be_driver)) {
846         return TPM_VERSION_UNSPEC;
847     }
848 
849     return tpm_backend_get_tpm_version(s->be_driver);
850 }
851 
852 /*
853  * This function is called when the machine starts, resets or due to
854  * S3 resume.
855  */
856 static void tpm_tis_reset(TPMState *s)
857 {
858     int c;
859 
860     s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
861     s->be_buffer_size = MIN(tpm_backend_get_buffer_size(s->be_driver),
862                             TPM_TIS_BUFFER_MAX);
863 
864     if (s->ppi_enabled) {
865         tpm_ppi_reset(&s->ppi);
866     }
867     tpm_backend_reset(s->be_driver);
868 
869     s->active_locty = TPM_TIS_NO_LOCALITY;
870     s->next_locty = TPM_TIS_NO_LOCALITY;
871     s->aborting_locty = TPM_TIS_NO_LOCALITY;
872 
873     for (c = 0; c < TPM_TIS_NUM_LOCALITIES; c++) {
874         s->loc[c].access = TPM_TIS_ACCESS_TPM_REG_VALID_STS;
875         switch (s->be_tpm_version) {
876         case TPM_VERSION_UNSPEC:
877             break;
878         case TPM_VERSION_1_2:
879             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY1_2;
880             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
881             break;
882         case TPM_VERSION_2_0:
883             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY2_0;
884             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0;
885             break;
886         }
887         s->loc[c].inte = TPM_TIS_INT_POLARITY_LOW_LEVEL;
888         s->loc[c].ints = 0;
889         s->loc[c].state = TPM_TIS_STATE_IDLE;
890 
891         s->rw_offset = 0;
892     }
893 
894     if (tpm_backend_startup_tpm(s->be_driver, s->be_buffer_size) < 0) {
895         exit(1);
896     }
897 }
898 
899 /* persistent state handling */
900 
901 static int tpm_tis_pre_save(TPMState *s)
902 {
903     uint8_t locty = s->active_locty;
904 
905     trace_tpm_tis_pre_save(locty, s->rw_offset);
906 
907     if (DEBUG_TIS) {
908         tpm_tis_dump_state(s, 0);
909     }
910 
911     /*
912      * Synchronize with backend completion.
913      */
914     tpm_backend_finish_sync(s->be_driver);
915 
916     return 0;
917 }
918 
919 static const VMStateDescription vmstate_locty = {
920     .name = "tpm-tis/locty",
921     .version_id = 0,
922     .fields      = (VMStateField[]) {
923         VMSTATE_UINT32(state, TPMLocality),
924         VMSTATE_UINT32(inte, TPMLocality),
925         VMSTATE_UINT32(ints, TPMLocality),
926         VMSTATE_UINT8(access, TPMLocality),
927         VMSTATE_UINT32(sts, TPMLocality),
928         VMSTATE_UINT32(iface_id, TPMLocality),
929         VMSTATE_END_OF_LIST(),
930     }
931 };
932 
933 /* ISA */
934 
935 static int tpm_tis_pre_save_isa(void *opaque)
936 {
937     TPMStateISA *isadev = opaque;
938 
939     return tpm_tis_pre_save(&isadev->state);
940 }
941 
942 static const VMStateDescription vmstate_tpm_tis_isa = {
943     .name = "tpm-tis",
944     .version_id = 0,
945     .pre_save  = tpm_tis_pre_save_isa,
946     .fields = (VMStateField[]) {
947         VMSTATE_BUFFER(state.buffer, TPMStateISA),
948         VMSTATE_UINT16(state.rw_offset, TPMStateISA),
949         VMSTATE_UINT8(state.active_locty, TPMStateISA),
950         VMSTATE_UINT8(state.aborting_locty, TPMStateISA),
951         VMSTATE_UINT8(state.next_locty, TPMStateISA),
952 
953         VMSTATE_STRUCT_ARRAY(state.loc, TPMStateISA, TPM_TIS_NUM_LOCALITIES, 0,
954                              vmstate_locty, TPMLocality),
955 
956         VMSTATE_END_OF_LIST()
957     }
958 };
959 
960 static void tpm_tis_isa_request_completed(TPMIf *ti, int ret)
961 {
962     TPMStateISA *isadev = TPM_TIS_ISA(ti);
963     TPMState *s = &isadev->state;
964 
965     tpm_tis_request_completed(s, ret);
966 }
967 
968 static enum TPMVersion tpm_tis_isa_get_tpm_version(TPMIf *ti)
969 {
970     TPMStateISA *isadev = TPM_TIS_ISA(ti);
971     TPMState *s = &isadev->state;
972 
973     return tpm_tis_get_tpm_version(s);
974 }
975 
976 static void tpm_tis_isa_reset(DeviceState *dev)
977 {
978     TPMStateISA *isadev = TPM_TIS_ISA(dev);
979     TPMState *s = &isadev->state;
980 
981     return tpm_tis_reset(s);
982 }
983 
984 static Property tpm_tis_isa_properties[] = {
985     DEFINE_PROP_UINT32("irq", TPMStateISA, state.irq_num, TPM_TIS_IRQ),
986     DEFINE_PROP_TPMBE("tpmdev", TPMStateISA, state.be_driver),
987     DEFINE_PROP_BOOL("ppi", TPMStateISA, state.ppi_enabled, true),
988     DEFINE_PROP_END_OF_LIST(),
989 };
990 
991 static void tpm_tis_isa_initfn(Object *obj)
992 {
993     TPMStateISA *isadev = TPM_TIS_ISA(obj);
994     TPMState *s = &isadev->state;
995 
996     memory_region_init_io(&s->mmio, obj, &tpm_tis_memory_ops,
997                           s, "tpm-tis-mmio",
998                           TPM_TIS_NUM_LOCALITIES << TPM_TIS_LOCALITY_SHIFT);
999 }
1000 
1001 static void tpm_tis_isa_realizefn(DeviceState *dev, Error **errp)
1002 {
1003     TPMStateISA *isadev = TPM_TIS_ISA(dev);
1004     TPMState *s = &isadev->state;
1005 
1006     if (!tpm_find()) {
1007         error_setg(errp, "at most one TPM device is permitted");
1008         return;
1009     }
1010 
1011     if (!s->be_driver) {
1012         error_setg(errp, "'tpmdev' property is required");
1013         return;
1014     }
1015     if (s->irq_num > 15) {
1016         error_setg(errp, "IRQ %d is outside valid range of 0 to 15",
1017                    s->irq_num);
1018         return;
1019     }
1020 
1021     isa_init_irq(ISA_DEVICE(dev), &s->irq, s->irq_num);
1022 
1023     memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
1024                                 TPM_TIS_ADDR_BASE, &s->mmio);
1025 
1026     if (s->ppi_enabled) {
1027         tpm_ppi_init(&s->ppi, isa_address_space(ISA_DEVICE(dev)),
1028                      TPM_PPI_ADDR_BASE, OBJECT(dev));
1029     }
1030 }
1031 
1032 static void tpm_tis_isa_class_init(ObjectClass *klass, void *data)
1033 {
1034     DeviceClass *dc = DEVICE_CLASS(klass);
1035     TPMIfClass *tc = TPM_IF_CLASS(klass);
1036 
1037     device_class_set_props(dc, tpm_tis_isa_properties);
1038     dc->vmsd  = &vmstate_tpm_tis_isa;
1039     tc->model = TPM_MODEL_TPM_TIS;
1040     dc->realize = tpm_tis_isa_realizefn;
1041     dc->reset = tpm_tis_isa_reset;
1042     tc->request_completed = tpm_tis_isa_request_completed;
1043     tc->get_version = tpm_tis_isa_get_tpm_version;
1044 }
1045 
1046 static const TypeInfo tpm_tis_isa_info = {
1047     .name = TYPE_TPM_TIS_ISA,
1048     .parent = TYPE_ISA_DEVICE,
1049     .instance_size = sizeof(TPMStateISA),
1050     .instance_init = tpm_tis_isa_initfn,
1051     .class_init  = tpm_tis_isa_class_init,
1052     .interfaces = (InterfaceInfo[]) {
1053         { TYPE_TPM_IF },
1054         { }
1055     }
1056 };
1057 
1058 static void tpm_tis_isa_register(void)
1059 {
1060     type_register_static(&tpm_tis_isa_info);
1061 }
1062 
1063 type_init(tpm_tis_isa_register)
1064