xref: /qemu/hw/tpm/tpm_tis_common.c (revision c03785440d1d949cad6fa515e456479c2ec9b212)
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 
35 #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
36 #define TPM_TIS_LOCALITY_SHIFT      12
37 #define TPM_TIS_NO_LOCALITY         0xff
38 
39 #define TPM_TIS_IS_VALID_LOCTY(x)   ((x) < TPM_TIS_NUM_LOCALITIES)
40 
41 #define TPM_TIS_BUFFER_MAX          4096
42 
43 typedef enum {
44     TPM_TIS_STATE_IDLE = 0,
45     TPM_TIS_STATE_READY,
46     TPM_TIS_STATE_COMPLETION,
47     TPM_TIS_STATE_EXECUTION,
48     TPM_TIS_STATE_RECEPTION,
49 } TPMTISState;
50 
51 typedef struct TPMSizedBuffer {
52     uint32_t size;
53     uint8_t  *buffer;
54 } TPMSizedBuffer;
55 
56 /* locality data  -- all fields are persisted */
57 typedef struct TPMLocality {
58     TPMTISState state;
59     uint8_t access;
60     uint32_t sts;
61     uint32_t iface_id;
62     uint32_t inte;
63     uint32_t ints;
64 
65     uint16_t w_offset;
66     uint16_t r_offset;
67     TPMSizedBuffer w_buffer;
68     TPMSizedBuffer r_buffer;
69 } TPMLocality;
70 
71 typedef struct TPMState {
72     ISADevice busdev;
73     MemoryRegion mmio;
74 
75     uint32_t offset;
76     uint8_t buf[TPM_TIS_BUFFER_MAX];
77 
78     uint8_t active_locty;
79     uint8_t aborting_locty;
80     uint8_t next_locty;
81 
82     TPMLocality loc[TPM_TIS_NUM_LOCALITIES];
83 
84     qemu_irq irq;
85     uint32_t irq_num;
86 
87     TPMBackendCmd cmd;
88 
89     TPMBackend *be_driver;
90     TPMVersion be_tpm_version;
91 } TPMState;
92 
93 #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS)
94 
95 #define DEBUG_TIS 0
96 
97 #define DPRINTF(fmt, ...) do { \
98     if (DEBUG_TIS) { \
99         printf(fmt, ## __VA_ARGS__); \
100     } \
101 } while (0);
102 
103 /* tis registers */
104 #define TPM_TIS_REG_ACCESS                0x00
105 #define TPM_TIS_REG_INT_ENABLE            0x08
106 #define TPM_TIS_REG_INT_VECTOR            0x0c
107 #define TPM_TIS_REG_INT_STATUS            0x10
108 #define TPM_TIS_REG_INTF_CAPABILITY       0x14
109 #define TPM_TIS_REG_STS                   0x18
110 #define TPM_TIS_REG_DATA_FIFO             0x24
111 #define TPM_TIS_REG_INTERFACE_ID          0x30
112 #define TPM_TIS_REG_DATA_XFIFO            0x80
113 #define TPM_TIS_REG_DATA_XFIFO_END        0xbc
114 #define TPM_TIS_REG_DID_VID               0xf00
115 #define TPM_TIS_REG_RID                   0xf04
116 
117 /* vendor-specific registers */
118 #define TPM_TIS_REG_DEBUG                 0xf90
119 
120 #define TPM_TIS_STS_TPM_FAMILY_MASK         (0x3 << 26)/* TPM 2.0 */
121 #define TPM_TIS_STS_TPM_FAMILY1_2           (0 << 26)  /* TPM 2.0 */
122 #define TPM_TIS_STS_TPM_FAMILY2_0           (1 << 26)  /* TPM 2.0 */
123 #define TPM_TIS_STS_RESET_ESTABLISHMENT_BIT (1 << 25)  /* TPM 2.0 */
124 #define TPM_TIS_STS_COMMAND_CANCEL          (1 << 24)  /* TPM 2.0 */
125 
126 #define TPM_TIS_STS_VALID                 (1 << 7)
127 #define TPM_TIS_STS_COMMAND_READY         (1 << 6)
128 #define TPM_TIS_STS_TPM_GO                (1 << 5)
129 #define TPM_TIS_STS_DATA_AVAILABLE        (1 << 4)
130 #define TPM_TIS_STS_EXPECT                (1 << 3)
131 #define TPM_TIS_STS_SELFTEST_DONE         (1 << 2)
132 #define TPM_TIS_STS_RESPONSE_RETRY        (1 << 1)
133 
134 #define TPM_TIS_BURST_COUNT_SHIFT         8
135 #define TPM_TIS_BURST_COUNT(X) \
136     ((X) << TPM_TIS_BURST_COUNT_SHIFT)
137 
138 #define TPM_TIS_ACCESS_TPM_REG_VALID_STS  (1 << 7)
139 #define TPM_TIS_ACCESS_ACTIVE_LOCALITY    (1 << 5)
140 #define TPM_TIS_ACCESS_BEEN_SEIZED        (1 << 4)
141 #define TPM_TIS_ACCESS_SEIZE              (1 << 3)
142 #define TPM_TIS_ACCESS_PENDING_REQUEST    (1 << 2)
143 #define TPM_TIS_ACCESS_REQUEST_USE        (1 << 1)
144 #define TPM_TIS_ACCESS_TPM_ESTABLISHMENT  (1 << 0)
145 
146 #define TPM_TIS_INT_ENABLED               (1 << 31)
147 #define TPM_TIS_INT_DATA_AVAILABLE        (1 << 0)
148 #define TPM_TIS_INT_STS_VALID             (1 << 1)
149 #define TPM_TIS_INT_LOCALITY_CHANGED      (1 << 2)
150 #define TPM_TIS_INT_COMMAND_READY         (1 << 7)
151 
152 #define TPM_TIS_INT_POLARITY_MASK         (3 << 3)
153 #define TPM_TIS_INT_POLARITY_LOW_LEVEL    (1 << 3)
154 
155 #define TPM_TIS_INTERRUPTS_SUPPORTED (TPM_TIS_INT_LOCALITY_CHANGED | \
156                                       TPM_TIS_INT_DATA_AVAILABLE   | \
157                                       TPM_TIS_INT_STS_VALID | \
158                                       TPM_TIS_INT_COMMAND_READY)
159 
160 #define TPM_TIS_CAP_INTERFACE_VERSION1_3 (2 << 28)
161 #define TPM_TIS_CAP_INTERFACE_VERSION1_3_FOR_TPM2_0 (3 << 28)
162 #define TPM_TIS_CAP_DATA_TRANSFER_64B    (3 << 9)
163 #define TPM_TIS_CAP_DATA_TRANSFER_LEGACY (0 << 9)
164 #define TPM_TIS_CAP_BURST_COUNT_DYNAMIC  (0 << 8)
165 #define TPM_TIS_CAP_INTERRUPT_LOW_LEVEL  (1 << 4) /* support is mandatory */
166 #define TPM_TIS_CAPABILITIES_SUPPORTED1_3 \
167     (TPM_TIS_CAP_INTERRUPT_LOW_LEVEL | \
168      TPM_TIS_CAP_BURST_COUNT_DYNAMIC | \
169      TPM_TIS_CAP_DATA_TRANSFER_64B | \
170      TPM_TIS_CAP_INTERFACE_VERSION1_3 | \
171      TPM_TIS_INTERRUPTS_SUPPORTED)
172 
173 #define TPM_TIS_CAPABILITIES_SUPPORTED2_0 \
174     (TPM_TIS_CAP_INTERRUPT_LOW_LEVEL | \
175      TPM_TIS_CAP_BURST_COUNT_DYNAMIC | \
176      TPM_TIS_CAP_DATA_TRANSFER_64B | \
177      TPM_TIS_CAP_INTERFACE_VERSION1_3_FOR_TPM2_0 | \
178      TPM_TIS_INTERRUPTS_SUPPORTED)
179 
180 #define TPM_TIS_IFACE_ID_INTERFACE_TIS1_3   (0xf)     /* TPM 2.0 */
181 #define TPM_TIS_IFACE_ID_INTERFACE_FIFO     (0x0)     /* TPM 2.0 */
182 #define TPM_TIS_IFACE_ID_INTERFACE_VER_FIFO (0 << 4)  /* TPM 2.0 */
183 #define TPM_TIS_IFACE_ID_CAP_5_LOCALITIES   (1 << 8)  /* TPM 2.0 */
184 #define TPM_TIS_IFACE_ID_CAP_TIS_SUPPORTED  (1 << 13) /* TPM 2.0 */
185 #define TPM_TIS_IFACE_ID_INT_SEL_LOCK       (1 << 19) /* TPM 2.0 */
186 
187 #define TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3 \
188     (TPM_TIS_IFACE_ID_INTERFACE_TIS1_3 | \
189      (~0u << 4)/* all of it is don't care */)
190 
191 /* if backend was a TPM 2.0: */
192 #define TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0 \
193     (TPM_TIS_IFACE_ID_INTERFACE_FIFO | \
194      TPM_TIS_IFACE_ID_INTERFACE_VER_FIFO | \
195      TPM_TIS_IFACE_ID_CAP_5_LOCALITIES | \
196      TPM_TIS_IFACE_ID_CAP_TIS_SUPPORTED)
197 
198 #define TPM_TIS_TPM_DID       0x0001
199 #define TPM_TIS_TPM_VID       PCI_VENDOR_ID_IBM
200 #define TPM_TIS_TPM_RID       0x0001
201 
202 #define TPM_TIS_NO_DATA_BYTE  0xff
203 
204 /* local prototypes */
205 
206 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
207                                   unsigned size);
208 
209 /* utility functions */
210 
211 static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
212 {
213     return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
214 }
215 
216 static uint32_t tpm_tis_get_size_from_buffer(const TPMSizedBuffer *sb)
217 {
218     return tpm_cmd_get_size(sb->buffer);
219 }
220 
221 static void tpm_tis_show_buffer(const TPMSizedBuffer *sb, const char *string)
222 {
223 #ifdef DEBUG_TIS
224     uint32_t len, i;
225 
226     len = tpm_tis_get_size_from_buffer(sb);
227     DPRINTF("tpm_tis: %s length = %d\n", string, len);
228     for (i = 0; i < len; i++) {
229         if (i && !(i % 16)) {
230             DPRINTF("\n");
231         }
232         DPRINTF("%.2X ", sb->buffer[i]);
233     }
234     DPRINTF("\n");
235 #endif
236 }
237 
238 /*
239  * Set the given flags in the STS register by clearing the register but
240  * preserving the SELFTEST_DONE and TPM_FAMILY_MASK flags and then setting
241  * the new flags.
242  *
243  * The SELFTEST_DONE flag is acquired from the backend that determines it by
244  * peeking into TPM commands.
245  *
246  * A VM suspend/resume will preserve the flag by storing it into the VM
247  * device state, but the backend will not remember it when QEMU is started
248  * again. Therefore, we cache the flag here. Once set, it will not be unset
249  * except by a reset.
250  */
251 static void tpm_tis_sts_set(TPMLocality *l, uint32_t flags)
252 {
253     l->sts &= TPM_TIS_STS_SELFTEST_DONE | TPM_TIS_STS_TPM_FAMILY_MASK;
254     l->sts |= flags;
255 }
256 
257 /*
258  * Send a request to the TPM.
259  */
260 static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
261 {
262     TPMLocality *locty_data = &s->loc[locty];
263 
264     tpm_tis_show_buffer(&s->loc[locty].w_buffer, "tpm_tis: To TPM");
265 
266     /*
267      * w_offset serves as length indicator for length of data;
268      * it's reset when the response comes back
269      */
270     s->loc[locty].state = TPM_TIS_STATE_EXECUTION;
271 
272     s->cmd = (TPMBackendCmd) {
273         .locty = locty,
274         .in = locty_data->w_buffer.buffer,
275         .in_len = locty_data->w_offset,
276         .out = locty_data->r_buffer.buffer,
277         .out_len = locty_data->r_buffer.size
278     };
279 
280     tpm_backend_deliver_request(s->be_driver, &s->cmd);
281 }
282 
283 /* raise an interrupt if allowed */
284 static void tpm_tis_raise_irq(TPMState *s, uint8_t locty, uint32_t irqmask)
285 {
286     if (!TPM_TIS_IS_VALID_LOCTY(locty)) {
287         return;
288     }
289 
290     if ((s->loc[locty].inte & TPM_TIS_INT_ENABLED) &&
291         (s->loc[locty].inte & irqmask)) {
292         DPRINTF("tpm_tis: Raising IRQ for flag %08x\n", irqmask);
293         qemu_irq_raise(s->irq);
294         s->loc[locty].ints |= irqmask;
295     }
296 }
297 
298 static uint32_t tpm_tis_check_request_use_except(TPMState *s, uint8_t locty)
299 {
300     uint8_t l;
301 
302     for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
303         if (l == locty) {
304             continue;
305         }
306         if ((s->loc[l].access & TPM_TIS_ACCESS_REQUEST_USE)) {
307             return 1;
308         }
309     }
310 
311     return 0;
312 }
313 
314 static void tpm_tis_new_active_locality(TPMState *s, uint8_t new_active_locty)
315 {
316     bool change = (s->active_locty != new_active_locty);
317     bool is_seize;
318     uint8_t mask;
319 
320     if (change && TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
321         is_seize = TPM_TIS_IS_VALID_LOCTY(new_active_locty) &&
322                    s->loc[new_active_locty].access & TPM_TIS_ACCESS_SEIZE;
323 
324         if (is_seize) {
325             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY);
326         } else {
327             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY|
328                      TPM_TIS_ACCESS_REQUEST_USE);
329         }
330         /* reset flags on the old active locality */
331         s->loc[s->active_locty].access &= mask;
332 
333         if (is_seize) {
334             s->loc[s->active_locty].access |= TPM_TIS_ACCESS_BEEN_SEIZED;
335         }
336     }
337 
338     s->active_locty = new_active_locty;
339 
340     DPRINTF("tpm_tis: Active locality is now %d\n", s->active_locty);
341 
342     if (TPM_TIS_IS_VALID_LOCTY(new_active_locty)) {
343         /* set flags on the new active locality */
344         s->loc[new_active_locty].access |= TPM_TIS_ACCESS_ACTIVE_LOCALITY;
345         s->loc[new_active_locty].access &= ~(TPM_TIS_ACCESS_REQUEST_USE |
346                                                TPM_TIS_ACCESS_SEIZE);
347     }
348 
349     if (change) {
350         tpm_tis_raise_irq(s, s->active_locty, TPM_TIS_INT_LOCALITY_CHANGED);
351     }
352 }
353 
354 /* abort -- this function switches the locality */
355 static void tpm_tis_abort(TPMState *s, uint8_t locty)
356 {
357     s->loc[locty].r_offset = 0;
358     s->loc[locty].w_offset = 0;
359 
360     DPRINTF("tpm_tis: tis_abort: new active locality is %d\n", s->next_locty);
361 
362     /*
363      * Need to react differently depending on who's aborting now and
364      * which locality will become active afterwards.
365      */
366     if (s->aborting_locty == s->next_locty) {
367         s->loc[s->aborting_locty].state = TPM_TIS_STATE_READY;
368         tpm_tis_sts_set(&s->loc[s->aborting_locty],
369                         TPM_TIS_STS_COMMAND_READY);
370         tpm_tis_raise_irq(s, s->aborting_locty, TPM_TIS_INT_COMMAND_READY);
371     }
372 
373     /* locality after abort is another one than the current one */
374     tpm_tis_new_active_locality(s, s->next_locty);
375 
376     s->next_locty = TPM_TIS_NO_LOCALITY;
377     /* nobody's aborting a command anymore */
378     s->aborting_locty = TPM_TIS_NO_LOCALITY;
379 }
380 
381 /* prepare aborting current command */
382 static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
383 {
384     uint8_t busy_locty;
385 
386     s->aborting_locty = locty;
387     s->next_locty = newlocty;  /* locality after successful abort */
388 
389     /*
390      * only abort a command using an interrupt if currently executing
391      * a command AND if there's a valid connection to the vTPM.
392      */
393     for (busy_locty = 0; busy_locty < TPM_TIS_NUM_LOCALITIES; busy_locty++) {
394         if (s->loc[busy_locty].state == TPM_TIS_STATE_EXECUTION) {
395             /*
396              * request the backend to cancel. Some backends may not
397              * support it
398              */
399             tpm_backend_cancel_cmd(s->be_driver);
400             return;
401         }
402     }
403 
404     tpm_tis_abort(s, locty);
405 }
406 
407 /*
408  * Callback from the TPM to indicate that the response was received.
409  */
410 static void tpm_tis_request_completed(TPMIf *ti)
411 {
412     TPMState *s = TPM(ti);
413     uint8_t locty = s->cmd.locty;
414     uint8_t l;
415 
416     if (s->cmd.selftest_done) {
417         for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
418             s->loc[locty].sts |= TPM_TIS_STS_SELFTEST_DONE;
419         }
420     }
421 
422     tpm_tis_sts_set(&s->loc[locty],
423                     TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
424     s->loc[locty].state = TPM_TIS_STATE_COMPLETION;
425     s->loc[locty].r_offset = 0;
426     s->loc[locty].w_offset = 0;
427 
428     tpm_tis_show_buffer(&s->loc[locty].r_buffer, "tpm_tis: From TPM");
429 
430     if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
431         tpm_tis_abort(s, locty);
432     }
433 
434     tpm_tis_raise_irq(s, locty,
435                       TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
436 }
437 
438 /*
439  * Read a byte of response data
440  */
441 static uint32_t tpm_tis_data_read(TPMState *s, uint8_t locty)
442 {
443     uint32_t ret = TPM_TIS_NO_DATA_BYTE;
444     uint16_t len;
445 
446     if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
447         len = tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer);
448 
449         ret = s->loc[locty].r_buffer.buffer[s->loc[locty].r_offset++];
450         if (s->loc[locty].r_offset >= len) {
451             /* got last byte */
452             tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
453             tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
454         }
455         DPRINTF("tpm_tis: tpm_tis_data_read byte 0x%02x   [%d]\n",
456                 ret, s->loc[locty].r_offset - 1);
457     }
458 
459     return ret;
460 }
461 
462 #ifdef DEBUG_TIS
463 static void tpm_tis_dump_state(void *opaque, hwaddr addr)
464 {
465     static const unsigned regs[] = {
466         TPM_TIS_REG_ACCESS,
467         TPM_TIS_REG_INT_ENABLE,
468         TPM_TIS_REG_INT_VECTOR,
469         TPM_TIS_REG_INT_STATUS,
470         TPM_TIS_REG_INTF_CAPABILITY,
471         TPM_TIS_REG_STS,
472         TPM_TIS_REG_DID_VID,
473         TPM_TIS_REG_RID,
474         0xfff};
475     int idx;
476     uint8_t locty = tpm_tis_locality_from_addr(addr);
477     hwaddr base = addr & ~0xfff;
478     TPMState *s = opaque;
479 
480     DPRINTF("tpm_tis: active locality      : %d\n"
481             "tpm_tis: state of locality %d : %d\n"
482             "tpm_tis: register dump:\n",
483             s->active_locty,
484             locty, s->loc[locty].state);
485 
486     for (idx = 0; regs[idx] != 0xfff; idx++) {
487         DPRINTF("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
488                 (int)tpm_tis_mmio_read(opaque, base + regs[idx], 4));
489     }
490 
491     DPRINTF("tpm_tis: read offset   : %d\n"
492             "tpm_tis: result buffer : ",
493             s->loc[locty].r_offset);
494     for (idx = 0;
495          idx < tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer);
496          idx++) {
497         DPRINTF("%c%02x%s",
498                 s->loc[locty].r_offset == idx ? '>' : ' ',
499                 s->loc[locty].r_buffer.buffer[idx],
500                 ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
501     }
502     DPRINTF("\n"
503             "tpm_tis: write offset  : %d\n"
504             "tpm_tis: request buffer: ",
505             s->loc[locty].w_offset);
506     for (idx = 0;
507          idx < tpm_tis_get_size_from_buffer(&s->loc[locty].w_buffer);
508          idx++) {
509         DPRINTF("%c%02x%s",
510                 s->loc[locty].w_offset == idx ? '>' : ' ',
511                 s->loc[locty].w_buffer.buffer[idx],
512                 ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
513     }
514     DPRINTF("\n");
515 }
516 #endif
517 
518 /*
519  * Read a register of the TIS interface
520  * See specs pages 33-63 for description of the registers
521  */
522 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
523                                   unsigned size)
524 {
525     TPMState *s = opaque;
526     uint16_t offset = addr & 0xffc;
527     uint8_t shift = (addr & 0x3) * 8;
528     uint32_t val = 0xffffffff;
529     uint8_t locty = tpm_tis_locality_from_addr(addr);
530     uint32_t avail;
531     uint8_t v;
532 
533     if (tpm_backend_had_startup_error(s->be_driver)) {
534         return 0;
535     }
536 
537     switch (offset) {
538     case TPM_TIS_REG_ACCESS:
539         /* never show the SEIZE flag even though we use it internally */
540         val = s->loc[locty].access & ~TPM_TIS_ACCESS_SEIZE;
541         /* the pending flag is always calculated */
542         if (tpm_tis_check_request_use_except(s, locty)) {
543             val |= TPM_TIS_ACCESS_PENDING_REQUEST;
544         }
545         val |= !tpm_backend_get_tpm_established_flag(s->be_driver);
546         break;
547     case TPM_TIS_REG_INT_ENABLE:
548         val = s->loc[locty].inte;
549         break;
550     case TPM_TIS_REG_INT_VECTOR:
551         val = s->irq_num;
552         break;
553     case TPM_TIS_REG_INT_STATUS:
554         val = s->loc[locty].ints;
555         break;
556     case TPM_TIS_REG_INTF_CAPABILITY:
557         switch (s->be_tpm_version) {
558         case TPM_VERSION_UNSPEC:
559             val = 0;
560             break;
561         case TPM_VERSION_1_2:
562             val = TPM_TIS_CAPABILITIES_SUPPORTED1_3;
563             break;
564         case TPM_VERSION_2_0:
565             val = TPM_TIS_CAPABILITIES_SUPPORTED2_0;
566             break;
567         }
568         break;
569     case TPM_TIS_REG_STS:
570         if (s->active_locty == locty) {
571             if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
572                 val = TPM_TIS_BURST_COUNT(
573                        tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer)
574                        - s->loc[locty].r_offset) | s->loc[locty].sts;
575             } else {
576                 avail = s->loc[locty].w_buffer.size
577                         - s->loc[locty].w_offset;
578                 /*
579                  * byte-sized reads should not return 0x00 for 0x100
580                  * available bytes.
581                  */
582                 if (size == 1 && avail > 0xff) {
583                     avail = 0xff;
584                 }
585                 val = TPM_TIS_BURST_COUNT(avail) | s->loc[locty].sts;
586             }
587         }
588         break;
589     case TPM_TIS_REG_DATA_FIFO:
590     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
591         if (s->active_locty == locty) {
592             if (size > 4 - (addr & 0x3)) {
593                 /* prevent access beyond FIFO */
594                 size = 4 - (addr & 0x3);
595             }
596             val = 0;
597             shift = 0;
598             while (size > 0) {
599                 switch (s->loc[locty].state) {
600                 case TPM_TIS_STATE_COMPLETION:
601                     v = tpm_tis_data_read(s, locty);
602                     break;
603                 default:
604                     v = TPM_TIS_NO_DATA_BYTE;
605                     break;
606                 }
607                 val |= (v << shift);
608                 shift += 8;
609                 size--;
610             }
611             shift = 0; /* no more adjustments */
612         }
613         break;
614     case TPM_TIS_REG_INTERFACE_ID:
615         val = s->loc[locty].iface_id;
616         break;
617     case TPM_TIS_REG_DID_VID:
618         val = (TPM_TIS_TPM_DID << 16) | TPM_TIS_TPM_VID;
619         break;
620     case TPM_TIS_REG_RID:
621         val = TPM_TIS_TPM_RID;
622         break;
623 #ifdef DEBUG_TIS
624     case TPM_TIS_REG_DEBUG:
625         tpm_tis_dump_state(opaque, addr);
626         break;
627 #endif
628     }
629 
630     if (shift) {
631         val >>= shift;
632     }
633 
634     DPRINTF("tpm_tis:  read.%u(%08x) = %08x\n", size, (int)addr, (int)val);
635 
636     return val;
637 }
638 
639 /*
640  * Write a value to a register of the TIS interface
641  * See specs pages 33-63 for description of the registers
642  */
643 static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
644                                uint64_t val, unsigned size)
645 {
646     TPMState *s = opaque;
647     uint16_t off = addr & 0xffc;
648     uint8_t shift = (addr & 0x3) * 8;
649     uint8_t locty = tpm_tis_locality_from_addr(addr);
650     uint8_t active_locty, l;
651     int c, set_new_locty = 1;
652     uint16_t len;
653     uint32_t mask = (size == 1) ? 0xff : ((size == 2) ? 0xffff : ~0);
654 
655     DPRINTF("tpm_tis: write.%u(%08x) = %08x\n", size, (int)addr, (int)val);
656 
657     if (locty == 4) {
658         DPRINTF("tpm_tis: Access to locality 4 only allowed from hardware\n");
659         return;
660     }
661 
662     if (tpm_backend_had_startup_error(s->be_driver)) {
663         return;
664     }
665 
666     val &= mask;
667 
668     if (shift) {
669         val <<= shift;
670         mask <<= shift;
671     }
672 
673     mask ^= 0xffffffff;
674 
675     switch (off) {
676     case TPM_TIS_REG_ACCESS:
677 
678         if ((val & TPM_TIS_ACCESS_SEIZE)) {
679             val &= ~(TPM_TIS_ACCESS_REQUEST_USE |
680                      TPM_TIS_ACCESS_ACTIVE_LOCALITY);
681         }
682 
683         active_locty = s->active_locty;
684 
685         if ((val & TPM_TIS_ACCESS_ACTIVE_LOCALITY)) {
686             /* give up locality if currently owned */
687             if (s->active_locty == locty) {
688                 DPRINTF("tpm_tis: Releasing locality %d\n", locty);
689 
690                 uint8_t newlocty = TPM_TIS_NO_LOCALITY;
691                 /* anybody wants the locality ? */
692                 for (c = TPM_TIS_NUM_LOCALITIES - 1; c >= 0; c--) {
693                     if ((s->loc[c].access & TPM_TIS_ACCESS_REQUEST_USE)) {
694                         DPRINTF("tpm_tis: Locality %d requests use.\n", c);
695                         newlocty = c;
696                         break;
697                     }
698                 }
699                 DPRINTF("tpm_tis: TPM_TIS_ACCESS_ACTIVE_LOCALITY: "
700                         "Next active locality: %d\n",
701                         newlocty);
702 
703                 if (TPM_TIS_IS_VALID_LOCTY(newlocty)) {
704                     set_new_locty = 0;
705                     tpm_tis_prep_abort(s, locty, newlocty);
706                 } else {
707                     active_locty = TPM_TIS_NO_LOCALITY;
708                 }
709             } else {
710                 /* not currently the owner; clear a pending request */
711                 s->loc[locty].access &= ~TPM_TIS_ACCESS_REQUEST_USE;
712             }
713         }
714 
715         if ((val & TPM_TIS_ACCESS_BEEN_SEIZED)) {
716             s->loc[locty].access &= ~TPM_TIS_ACCESS_BEEN_SEIZED;
717         }
718 
719         if ((val & TPM_TIS_ACCESS_SEIZE)) {
720             /*
721              * allow seize if a locality is active and the requesting
722              * locality is higher than the one that's active
723              * OR
724              * allow seize for requesting locality if no locality is
725              * active
726              */
727             while ((TPM_TIS_IS_VALID_LOCTY(s->active_locty) &&
728                     locty > s->active_locty) ||
729                     !TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
730                 bool higher_seize = FALSE;
731 
732                 /* already a pending SEIZE ? */
733                 if ((s->loc[locty].access & TPM_TIS_ACCESS_SEIZE)) {
734                     break;
735                 }
736 
737                 /* check for ongoing seize by a higher locality */
738                 for (l = locty + 1; l < TPM_TIS_NUM_LOCALITIES; l++) {
739                     if ((s->loc[l].access & TPM_TIS_ACCESS_SEIZE)) {
740                         higher_seize = TRUE;
741                         break;
742                     }
743                 }
744 
745                 if (higher_seize) {
746                     break;
747                 }
748 
749                 /* cancel any seize by a lower locality */
750                 for (l = 0; l < locty - 1; l++) {
751                     s->loc[l].access &= ~TPM_TIS_ACCESS_SEIZE;
752                 }
753 
754                 s->loc[locty].access |= TPM_TIS_ACCESS_SEIZE;
755                 DPRINTF("tpm_tis: TPM_TIS_ACCESS_SEIZE: "
756                         "Locality %d seized from locality %d\n",
757                         locty, s->active_locty);
758                 DPRINTF("tpm_tis: TPM_TIS_ACCESS_SEIZE: Initiating abort.\n");
759                 set_new_locty = 0;
760                 tpm_tis_prep_abort(s, s->active_locty, locty);
761                 break;
762             }
763         }
764 
765         if ((val & TPM_TIS_ACCESS_REQUEST_USE)) {
766             if (s->active_locty != locty) {
767                 if (TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
768                     s->loc[locty].access |= TPM_TIS_ACCESS_REQUEST_USE;
769                 } else {
770                     /* no locality active -> make this one active now */
771                     active_locty = locty;
772                 }
773             }
774         }
775 
776         if (set_new_locty) {
777             tpm_tis_new_active_locality(s, active_locty);
778         }
779 
780         break;
781     case TPM_TIS_REG_INT_ENABLE:
782         if (s->active_locty != locty) {
783             break;
784         }
785 
786         s->loc[locty].inte &= mask;
787         s->loc[locty].inte |= (val & (TPM_TIS_INT_ENABLED |
788                                         TPM_TIS_INT_POLARITY_MASK |
789                                         TPM_TIS_INTERRUPTS_SUPPORTED));
790         break;
791     case TPM_TIS_REG_INT_VECTOR:
792         /* hard wired -- ignore */
793         break;
794     case TPM_TIS_REG_INT_STATUS:
795         if (s->active_locty != locty) {
796             break;
797         }
798 
799         /* clearing of interrupt flags */
800         if (((val & TPM_TIS_INTERRUPTS_SUPPORTED)) &&
801             (s->loc[locty].ints & TPM_TIS_INTERRUPTS_SUPPORTED)) {
802             s->loc[locty].ints &= ~val;
803             if (s->loc[locty].ints == 0) {
804                 qemu_irq_lower(s->irq);
805                 DPRINTF("tpm_tis: Lowering IRQ\n");
806             }
807         }
808         s->loc[locty].ints &= ~(val & TPM_TIS_INTERRUPTS_SUPPORTED);
809         break;
810     case TPM_TIS_REG_STS:
811         if (s->active_locty != locty) {
812             break;
813         }
814 
815         if (s->be_tpm_version == TPM_VERSION_2_0) {
816             /* some flags that are only supported for TPM 2 */
817             if (val & TPM_TIS_STS_COMMAND_CANCEL) {
818                 if (s->loc[locty].state == TPM_TIS_STATE_EXECUTION) {
819                     /*
820                      * request the backend to cancel. Some backends may not
821                      * support it
822                      */
823                     tpm_backend_cancel_cmd(s->be_driver);
824                 }
825             }
826 
827             if (val & TPM_TIS_STS_RESET_ESTABLISHMENT_BIT) {
828                 if (locty == 3 || locty == 4) {
829                     tpm_backend_reset_tpm_established_flag(s->be_driver, locty);
830                 }
831             }
832         }
833 
834         val &= (TPM_TIS_STS_COMMAND_READY | TPM_TIS_STS_TPM_GO |
835                 TPM_TIS_STS_RESPONSE_RETRY);
836 
837         if (val == TPM_TIS_STS_COMMAND_READY) {
838             switch (s->loc[locty].state) {
839 
840             case TPM_TIS_STATE_READY:
841                 s->loc[locty].w_offset = 0;
842                 s->loc[locty].r_offset = 0;
843             break;
844 
845             case TPM_TIS_STATE_IDLE:
846                 tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_COMMAND_READY);
847                 s->loc[locty].state = TPM_TIS_STATE_READY;
848                 tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
849             break;
850 
851             case TPM_TIS_STATE_EXECUTION:
852             case TPM_TIS_STATE_RECEPTION:
853                 /* abort currently running command */
854                 DPRINTF("tpm_tis: %s: Initiating abort.\n",
855                         __func__);
856                 tpm_tis_prep_abort(s, locty, locty);
857             break;
858 
859             case TPM_TIS_STATE_COMPLETION:
860                 s->loc[locty].w_offset = 0;
861                 s->loc[locty].r_offset = 0;
862                 /* shortcut to ready state with C/R set */
863                 s->loc[locty].state = TPM_TIS_STATE_READY;
864                 if (!(s->loc[locty].sts & TPM_TIS_STS_COMMAND_READY)) {
865                     tpm_tis_sts_set(&s->loc[locty],
866                                     TPM_TIS_STS_COMMAND_READY);
867                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
868                 }
869                 s->loc[locty].sts &= ~(TPM_TIS_STS_DATA_AVAILABLE);
870             break;
871 
872             }
873         } else if (val == TPM_TIS_STS_TPM_GO) {
874             switch (s->loc[locty].state) {
875             case TPM_TIS_STATE_RECEPTION:
876                 if ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) == 0) {
877                     tpm_tis_tpm_send(s, locty);
878                 }
879                 break;
880             default:
881                 /* ignore */
882                 break;
883             }
884         } else if (val == TPM_TIS_STS_RESPONSE_RETRY) {
885             switch (s->loc[locty].state) {
886             case TPM_TIS_STATE_COMPLETION:
887                 s->loc[locty].r_offset = 0;
888                 tpm_tis_sts_set(&s->loc[locty],
889                                 TPM_TIS_STS_VALID|
890                                 TPM_TIS_STS_DATA_AVAILABLE);
891                 break;
892             default:
893                 /* ignore */
894                 break;
895             }
896         }
897         break;
898     case TPM_TIS_REG_DATA_FIFO:
899     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
900         /* data fifo */
901         if (s->active_locty != locty) {
902             break;
903         }
904 
905         if (s->loc[locty].state == TPM_TIS_STATE_IDLE ||
906             s->loc[locty].state == TPM_TIS_STATE_EXECUTION ||
907             s->loc[locty].state == TPM_TIS_STATE_COMPLETION) {
908             /* drop the byte */
909         } else {
910             DPRINTF("tpm_tis: Data to send to TPM: %08x (size=%d)\n",
911                     (int)val, size);
912             if (s->loc[locty].state == TPM_TIS_STATE_READY) {
913                 s->loc[locty].state = TPM_TIS_STATE_RECEPTION;
914                 tpm_tis_sts_set(&s->loc[locty],
915                                 TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
916             }
917 
918             val >>= shift;
919             if (size > 4 - (addr & 0x3)) {
920                 /* prevent access beyond FIFO */
921                 size = 4 - (addr & 0x3);
922             }
923 
924             while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
925                 if (s->loc[locty].w_offset < s->loc[locty].w_buffer.size) {
926                     s->loc[locty].w_buffer.
927                         buffer[s->loc[locty].w_offset++] = (uint8_t)val;
928                     val >>= 8;
929                     size--;
930                 } else {
931                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
932                 }
933             }
934 
935             /* check for complete packet */
936             if (s->loc[locty].w_offset > 5 &&
937                 (s->loc[locty].sts & TPM_TIS_STS_EXPECT)) {
938                 /* we have a packet length - see if we have all of it */
939                 bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
940 
941                 len = tpm_tis_get_size_from_buffer(&s->loc[locty].w_buffer);
942                 if (len > s->loc[locty].w_offset) {
943                     tpm_tis_sts_set(&s->loc[locty],
944                                     TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
945                 } else {
946                     /* packet complete */
947                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
948                 }
949                 if (need_irq) {
950                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
951                 }
952             }
953         }
954         break;
955     case TPM_TIS_REG_INTERFACE_ID:
956         if (val & TPM_TIS_IFACE_ID_INT_SEL_LOCK) {
957             for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
958                 s->loc[l].iface_id |= TPM_TIS_IFACE_ID_INT_SEL_LOCK;
959             }
960         }
961         break;
962     }
963 }
964 
965 static const MemoryRegionOps tpm_tis_memory_ops = {
966     .read = tpm_tis_mmio_read,
967     .write = tpm_tis_mmio_write,
968     .endianness = DEVICE_LITTLE_ENDIAN,
969     .valid = {
970         .min_access_size = 1,
971         .max_access_size = 4,
972     },
973 };
974 
975 static int tpm_tis_do_startup_tpm(TPMState *s)
976 {
977     return tpm_backend_startup_tpm(s->be_driver);
978 }
979 
980 static void tpm_tis_realloc_buffer(TPMSizedBuffer *sb)
981 {
982     size_t wanted_size = 4096; /* Linux tpm.c buffer size */
983 
984     if (sb->size != wanted_size) {
985         sb->buffer = g_realloc(sb->buffer, wanted_size);
986         sb->size = wanted_size;
987     }
988 }
989 
990 /*
991  * Get the TPMVersion of the backend device being used
992  */
993 static enum TPMVersion tpm_tis_get_tpm_version(TPMIf *ti)
994 {
995     TPMState *s = TPM(ti);
996 
997     if (tpm_backend_had_startup_error(s->be_driver)) {
998         return TPM_VERSION_UNSPEC;
999     }
1000 
1001     return tpm_backend_get_tpm_version(s->be_driver);
1002 }
1003 
1004 /*
1005  * This function is called when the machine starts, resets or due to
1006  * S3 resume.
1007  */
1008 static void tpm_tis_reset(DeviceState *dev)
1009 {
1010     TPMState *s = TPM(dev);
1011     int c;
1012 
1013     s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
1014 
1015     tpm_backend_reset(s->be_driver);
1016 
1017     s->active_locty = TPM_TIS_NO_LOCALITY;
1018     s->next_locty = TPM_TIS_NO_LOCALITY;
1019     s->aborting_locty = TPM_TIS_NO_LOCALITY;
1020 
1021     for (c = 0; c < TPM_TIS_NUM_LOCALITIES; c++) {
1022         s->loc[c].access = TPM_TIS_ACCESS_TPM_REG_VALID_STS;
1023         switch (s->be_tpm_version) {
1024         case TPM_VERSION_UNSPEC:
1025             break;
1026         case TPM_VERSION_1_2:
1027             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY1_2;
1028             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
1029             break;
1030         case TPM_VERSION_2_0:
1031             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY2_0;
1032             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0;
1033             break;
1034         }
1035         s->loc[c].inte = TPM_TIS_INT_POLARITY_LOW_LEVEL;
1036         s->loc[c].ints = 0;
1037         s->loc[c].state = TPM_TIS_STATE_IDLE;
1038 
1039         s->loc[c].w_offset = 0;
1040         tpm_tis_realloc_buffer(&s->loc[c].w_buffer);
1041         s->loc[c].r_offset = 0;
1042         tpm_tis_realloc_buffer(&s->loc[c].r_buffer);
1043     }
1044 
1045     tpm_tis_do_startup_tpm(s);
1046 }
1047 
1048 static const VMStateDescription vmstate_tpm_tis = {
1049     .name = "tpm",
1050     .unmigratable = 1,
1051 };
1052 
1053 static Property tpm_tis_properties[] = {
1054     DEFINE_PROP_UINT32("irq", TPMState, irq_num, TPM_TIS_IRQ),
1055     DEFINE_PROP_TPMBE("tpmdev", TPMState, be_driver),
1056     DEFINE_PROP_END_OF_LIST(),
1057 };
1058 
1059 static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
1060 {
1061     TPMState *s = TPM(dev);
1062 
1063     if (!tpm_find()) {
1064         error_setg(errp, "at most one TPM device is permitted");
1065         return;
1066     }
1067 
1068     if (!s->be_driver) {
1069         error_setg(errp, "'tpmdev' property is required");
1070         return;
1071     }
1072     if (s->irq_num > 15) {
1073         error_setg(errp, "IRQ %d is outside valid range of 0 to 15",
1074                    s->irq_num);
1075         return;
1076     }
1077 
1078     isa_init_irq(&s->busdev, &s->irq, s->irq_num);
1079 
1080     memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
1081                                 TPM_TIS_ADDR_BASE, &s->mmio);
1082 }
1083 
1084 static void tpm_tis_initfn(Object *obj)
1085 {
1086     TPMState *s = TPM(obj);
1087 
1088     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_tis_memory_ops,
1089                           s, "tpm-tis-mmio",
1090                           TPM_TIS_NUM_LOCALITIES << TPM_TIS_LOCALITY_SHIFT);
1091 }
1092 
1093 static void tpm_tis_class_init(ObjectClass *klass, void *data)
1094 {
1095     DeviceClass *dc = DEVICE_CLASS(klass);
1096     TPMIfClass *tc = TPM_IF_CLASS(klass);
1097 
1098     dc->realize = tpm_tis_realizefn;
1099     dc->props = tpm_tis_properties;
1100     dc->reset = tpm_tis_reset;
1101     dc->vmsd  = &vmstate_tpm_tis;
1102     tc->model = TPM_MODEL_TPM_TIS;
1103     tc->get_version = tpm_tis_get_tpm_version;
1104     tc->request_completed = tpm_tis_request_completed;
1105 }
1106 
1107 static const TypeInfo tpm_tis_info = {
1108     .name = TYPE_TPM_TIS,
1109     .parent = TYPE_ISA_DEVICE,
1110     .instance_size = sizeof(TPMState),
1111     .instance_init = tpm_tis_initfn,
1112     .class_init  = tpm_tis_class_init,
1113     .interfaces = (InterfaceInfo[]) {
1114         { TYPE_TPM_IF },
1115         { }
1116     }
1117 };
1118 
1119 static void tpm_tis_register(void)
1120 {
1121     type_register_static(&tpm_tis_info);
1122     tpm_register_model(TPM_MODEL_TPM_TIS);
1123 }
1124 
1125 type_init(tpm_tis_register)
1126