xref: /qemu/hw/tpm/tpm_tis_common.c (revision 8a89c9ac15981c2d15ce4ee6d6ad67da58824a04)
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 "sysemu/tpm_backend.h"
28 #include "tpm_int.h"
29 #include "sysemu/block-backend.h"
30 #include "exec/address-spaces.h"
31 #include "hw/hw.h"
32 #include "hw/i386/pc.h"
33 #include "hw/pci/pci_ids.h"
34 #include "qapi/error.h"
35 #include "qemu-common.h"
36 #include "qemu/main-loop.h"
37 #include "hw/acpi/tpm.h"
38 
39 #define TPM_TIS_NUM_LOCALITIES      5     /* per spec */
40 #define TPM_TIS_LOCALITY_SHIFT      12
41 #define TPM_TIS_NO_LOCALITY         0xff
42 
43 #define TPM_TIS_IS_VALID_LOCTY(x)   ((x) < TPM_TIS_NUM_LOCALITIES)
44 
45 #define TPM_TIS_BUFFER_MAX          4096
46 
47 typedef enum {
48     TPM_TIS_STATE_IDLE = 0,
49     TPM_TIS_STATE_READY,
50     TPM_TIS_STATE_COMPLETION,
51     TPM_TIS_STATE_EXECUTION,
52     TPM_TIS_STATE_RECEPTION,
53 } TPMTISState;
54 
55 typedef struct TPMSizedBuffer {
56     uint32_t size;
57     uint8_t  *buffer;
58 } TPMSizedBuffer;
59 
60 /* locality data  -- all fields are persisted */
61 typedef struct TPMLocality {
62     TPMTISState state;
63     uint8_t access;
64     uint32_t sts;
65     uint32_t iface_id;
66     uint32_t inte;
67     uint32_t ints;
68 
69     uint16_t w_offset;
70     uint16_t r_offset;
71     TPMSizedBuffer w_buffer;
72     TPMSizedBuffer r_buffer;
73 } TPMLocality;
74 
75 struct TPMState {
76     ISADevice busdev;
77     MemoryRegion mmio;
78 
79     QEMUBH *bh;
80     uint32_t offset;
81     uint8_t buf[TPM_TIS_BUFFER_MAX];
82 
83     uint8_t active_locty;
84     uint8_t aborting_locty;
85     uint8_t next_locty;
86 
87     TPMLocality loc[TPM_TIS_NUM_LOCALITIES];
88 
89     qemu_irq irq;
90     uint32_t irq_num;
91 
92     TPMBackendCmd cmd;
93 
94     char *backend;
95     TPMBackend *be_driver;
96     TPMVersion be_tpm_version;
97 };
98 
99 #define TPM(obj) OBJECT_CHECK(TPMState, (obj), TYPE_TPM_TIS)
100 
101 #define DEBUG_TIS 0
102 
103 #define DPRINTF(fmt, ...) do { \
104     if (DEBUG_TIS) { \
105         printf(fmt, ## __VA_ARGS__); \
106     } \
107 } while (0);
108 
109 /* tis registers */
110 #define TPM_TIS_REG_ACCESS                0x00
111 #define TPM_TIS_REG_INT_ENABLE            0x08
112 #define TPM_TIS_REG_INT_VECTOR            0x0c
113 #define TPM_TIS_REG_INT_STATUS            0x10
114 #define TPM_TIS_REG_INTF_CAPABILITY       0x14
115 #define TPM_TIS_REG_STS                   0x18
116 #define TPM_TIS_REG_DATA_FIFO             0x24
117 #define TPM_TIS_REG_INTERFACE_ID          0x30
118 #define TPM_TIS_REG_DATA_XFIFO            0x80
119 #define TPM_TIS_REG_DATA_XFIFO_END        0xbc
120 #define TPM_TIS_REG_DID_VID               0xf00
121 #define TPM_TIS_REG_RID                   0xf04
122 
123 /* vendor-specific registers */
124 #define TPM_TIS_REG_DEBUG                 0xf90
125 
126 #define TPM_TIS_STS_TPM_FAMILY_MASK         (0x3 << 26)/* TPM 2.0 */
127 #define TPM_TIS_STS_TPM_FAMILY1_2           (0 << 26)  /* TPM 2.0 */
128 #define TPM_TIS_STS_TPM_FAMILY2_0           (1 << 26)  /* TPM 2.0 */
129 #define TPM_TIS_STS_RESET_ESTABLISHMENT_BIT (1 << 25)  /* TPM 2.0 */
130 #define TPM_TIS_STS_COMMAND_CANCEL          (1 << 24)  /* TPM 2.0 */
131 
132 #define TPM_TIS_STS_VALID                 (1 << 7)
133 #define TPM_TIS_STS_COMMAND_READY         (1 << 6)
134 #define TPM_TIS_STS_TPM_GO                (1 << 5)
135 #define TPM_TIS_STS_DATA_AVAILABLE        (1 << 4)
136 #define TPM_TIS_STS_EXPECT                (1 << 3)
137 #define TPM_TIS_STS_SELFTEST_DONE         (1 << 2)
138 #define TPM_TIS_STS_RESPONSE_RETRY        (1 << 1)
139 
140 #define TPM_TIS_BURST_COUNT_SHIFT         8
141 #define TPM_TIS_BURST_COUNT(X) \
142     ((X) << TPM_TIS_BURST_COUNT_SHIFT)
143 
144 #define TPM_TIS_ACCESS_TPM_REG_VALID_STS  (1 << 7)
145 #define TPM_TIS_ACCESS_ACTIVE_LOCALITY    (1 << 5)
146 #define TPM_TIS_ACCESS_BEEN_SEIZED        (1 << 4)
147 #define TPM_TIS_ACCESS_SEIZE              (1 << 3)
148 #define TPM_TIS_ACCESS_PENDING_REQUEST    (1 << 2)
149 #define TPM_TIS_ACCESS_REQUEST_USE        (1 << 1)
150 #define TPM_TIS_ACCESS_TPM_ESTABLISHMENT  (1 << 0)
151 
152 #define TPM_TIS_INT_ENABLED               (1 << 31)
153 #define TPM_TIS_INT_DATA_AVAILABLE        (1 << 0)
154 #define TPM_TIS_INT_STS_VALID             (1 << 1)
155 #define TPM_TIS_INT_LOCALITY_CHANGED      (1 << 2)
156 #define TPM_TIS_INT_COMMAND_READY         (1 << 7)
157 
158 #define TPM_TIS_INT_POLARITY_MASK         (3 << 3)
159 #define TPM_TIS_INT_POLARITY_LOW_LEVEL    (1 << 3)
160 
161 #define TPM_TIS_INTERRUPTS_SUPPORTED (TPM_TIS_INT_LOCALITY_CHANGED | \
162                                       TPM_TIS_INT_DATA_AVAILABLE   | \
163                                       TPM_TIS_INT_STS_VALID | \
164                                       TPM_TIS_INT_COMMAND_READY)
165 
166 #define TPM_TIS_CAP_INTERFACE_VERSION1_3 (2 << 28)
167 #define TPM_TIS_CAP_INTERFACE_VERSION1_3_FOR_TPM2_0 (3 << 28)
168 #define TPM_TIS_CAP_DATA_TRANSFER_64B    (3 << 9)
169 #define TPM_TIS_CAP_DATA_TRANSFER_LEGACY (0 << 9)
170 #define TPM_TIS_CAP_BURST_COUNT_DYNAMIC  (0 << 8)
171 #define TPM_TIS_CAP_INTERRUPT_LOW_LEVEL  (1 << 4) /* support is mandatory */
172 #define TPM_TIS_CAPABILITIES_SUPPORTED1_3 \
173     (TPM_TIS_CAP_INTERRUPT_LOW_LEVEL | \
174      TPM_TIS_CAP_BURST_COUNT_DYNAMIC | \
175      TPM_TIS_CAP_DATA_TRANSFER_64B | \
176      TPM_TIS_CAP_INTERFACE_VERSION1_3 | \
177      TPM_TIS_INTERRUPTS_SUPPORTED)
178 
179 #define TPM_TIS_CAPABILITIES_SUPPORTED2_0 \
180     (TPM_TIS_CAP_INTERRUPT_LOW_LEVEL | \
181      TPM_TIS_CAP_BURST_COUNT_DYNAMIC | \
182      TPM_TIS_CAP_DATA_TRANSFER_64B | \
183      TPM_TIS_CAP_INTERFACE_VERSION1_3_FOR_TPM2_0 | \
184      TPM_TIS_INTERRUPTS_SUPPORTED)
185 
186 #define TPM_TIS_IFACE_ID_INTERFACE_TIS1_3   (0xf)     /* TPM 2.0 */
187 #define TPM_TIS_IFACE_ID_INTERFACE_FIFO     (0x0)     /* TPM 2.0 */
188 #define TPM_TIS_IFACE_ID_INTERFACE_VER_FIFO (0 << 4)  /* TPM 2.0 */
189 #define TPM_TIS_IFACE_ID_CAP_5_LOCALITIES   (1 << 8)  /* TPM 2.0 */
190 #define TPM_TIS_IFACE_ID_CAP_TIS_SUPPORTED  (1 << 13) /* TPM 2.0 */
191 #define TPM_TIS_IFACE_ID_INT_SEL_LOCK       (1 << 19) /* TPM 2.0 */
192 
193 #define TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3 \
194     (TPM_TIS_IFACE_ID_INTERFACE_TIS1_3 | \
195      (~0u << 4)/* all of it is don't care */)
196 
197 /* if backend was a TPM 2.0: */
198 #define TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0 \
199     (TPM_TIS_IFACE_ID_INTERFACE_FIFO | \
200      TPM_TIS_IFACE_ID_INTERFACE_VER_FIFO | \
201      TPM_TIS_IFACE_ID_CAP_5_LOCALITIES | \
202      TPM_TIS_IFACE_ID_CAP_TIS_SUPPORTED)
203 
204 #define TPM_TIS_TPM_DID       0x0001
205 #define TPM_TIS_TPM_VID       PCI_VENDOR_ID_IBM
206 #define TPM_TIS_TPM_RID       0x0001
207 
208 #define TPM_TIS_NO_DATA_BYTE  0xff
209 
210 /* local prototypes */
211 
212 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
213                                   unsigned size);
214 
215 /* utility functions */
216 
217 static uint8_t tpm_tis_locality_from_addr(hwaddr addr)
218 {
219     return (uint8_t)((addr >> TPM_TIS_LOCALITY_SHIFT) & 0x7);
220 }
221 
222 static uint32_t tpm_tis_get_size_from_buffer(const TPMSizedBuffer *sb)
223 {
224     return be32_to_cpu(*(uint32_t *)&sb->buffer[2]);
225 }
226 
227 static void tpm_tis_show_buffer(const TPMSizedBuffer *sb, const char *string)
228 {
229 #ifdef DEBUG_TIS
230     uint32_t len, i;
231 
232     len = tpm_tis_get_size_from_buffer(sb);
233     DPRINTF("tpm_tis: %s length = %d\n", string, len);
234     for (i = 0; i < len; i++) {
235         if (i && !(i % 16)) {
236             DPRINTF("\n");
237         }
238         DPRINTF("%.2X ", sb->buffer[i]);
239     }
240     DPRINTF("\n");
241 #endif
242 }
243 
244 /*
245  * Set the given flags in the STS register by clearing the register but
246  * preserving the SELFTEST_DONE and TPM_FAMILY_MASK flags and then setting
247  * the new flags.
248  *
249  * The SELFTEST_DONE flag is acquired from the backend that determines it by
250  * peeking into TPM commands.
251  *
252  * A VM suspend/resume will preserve the flag by storing it into the VM
253  * device state, but the backend will not remember it when QEMU is started
254  * again. Therefore, we cache the flag here. Once set, it will not be unset
255  * except by a reset.
256  */
257 static void tpm_tis_sts_set(TPMLocality *l, uint32_t flags)
258 {
259     l->sts &= TPM_TIS_STS_SELFTEST_DONE | TPM_TIS_STS_TPM_FAMILY_MASK;
260     l->sts |= flags;
261 }
262 
263 /*
264  * Send a request to the TPM.
265  */
266 static void tpm_tis_tpm_send(TPMState *s, uint8_t locty)
267 {
268     TPMLocality *locty_data = &s->loc[locty];
269 
270     tpm_tis_show_buffer(&s->loc[locty].w_buffer, "tpm_tis: To TPM");
271 
272     /*
273      * w_offset serves as length indicator for length of data;
274      * it's reset when the response comes back
275      */
276     s->loc[locty].state = TPM_TIS_STATE_EXECUTION;
277 
278     s->cmd = (TPMBackendCmd) {
279         .locty = locty,
280         .in = locty_data->w_buffer.buffer,
281         .in_len = locty_data->w_offset,
282         .out = locty_data->r_buffer.buffer,
283         .out_len = locty_data->r_buffer.size
284     };
285 
286     tpm_backend_deliver_request(s->be_driver, &s->cmd);
287 }
288 
289 /* raise an interrupt if allowed */
290 static void tpm_tis_raise_irq(TPMState *s, uint8_t locty, uint32_t irqmask)
291 {
292     if (!TPM_TIS_IS_VALID_LOCTY(locty)) {
293         return;
294     }
295 
296     if ((s->loc[locty].inte & TPM_TIS_INT_ENABLED) &&
297         (s->loc[locty].inte & irqmask)) {
298         DPRINTF("tpm_tis: Raising IRQ for flag %08x\n", irqmask);
299         qemu_irq_raise(s->irq);
300         s->loc[locty].ints |= irqmask;
301     }
302 }
303 
304 static uint32_t tpm_tis_check_request_use_except(TPMState *s, uint8_t locty)
305 {
306     uint8_t l;
307 
308     for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
309         if (l == locty) {
310             continue;
311         }
312         if ((s->loc[l].access & TPM_TIS_ACCESS_REQUEST_USE)) {
313             return 1;
314         }
315     }
316 
317     return 0;
318 }
319 
320 static void tpm_tis_new_active_locality(TPMState *s, uint8_t new_active_locty)
321 {
322     bool change = (s->active_locty != new_active_locty);
323     bool is_seize;
324     uint8_t mask;
325 
326     if (change && TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
327         is_seize = TPM_TIS_IS_VALID_LOCTY(new_active_locty) &&
328                    s->loc[new_active_locty].access & TPM_TIS_ACCESS_SEIZE;
329 
330         if (is_seize) {
331             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY);
332         } else {
333             mask = ~(TPM_TIS_ACCESS_ACTIVE_LOCALITY|
334                      TPM_TIS_ACCESS_REQUEST_USE);
335         }
336         /* reset flags on the old active locality */
337         s->loc[s->active_locty].access &= mask;
338 
339         if (is_seize) {
340             s->loc[s->active_locty].access |= TPM_TIS_ACCESS_BEEN_SEIZED;
341         }
342     }
343 
344     s->active_locty = new_active_locty;
345 
346     DPRINTF("tpm_tis: Active locality is now %d\n", s->active_locty);
347 
348     if (TPM_TIS_IS_VALID_LOCTY(new_active_locty)) {
349         /* set flags on the new active locality */
350         s->loc[new_active_locty].access |= TPM_TIS_ACCESS_ACTIVE_LOCALITY;
351         s->loc[new_active_locty].access &= ~(TPM_TIS_ACCESS_REQUEST_USE |
352                                                TPM_TIS_ACCESS_SEIZE);
353     }
354 
355     if (change) {
356         tpm_tis_raise_irq(s, s->active_locty, TPM_TIS_INT_LOCALITY_CHANGED);
357     }
358 }
359 
360 /* abort -- this function switches the locality */
361 static void tpm_tis_abort(TPMState *s, uint8_t locty)
362 {
363     s->loc[locty].r_offset = 0;
364     s->loc[locty].w_offset = 0;
365 
366     DPRINTF("tpm_tis: tis_abort: new active locality is %d\n", s->next_locty);
367 
368     /*
369      * Need to react differently depending on who's aborting now and
370      * which locality will become active afterwards.
371      */
372     if (s->aborting_locty == s->next_locty) {
373         s->loc[s->aborting_locty].state = TPM_TIS_STATE_READY;
374         tpm_tis_sts_set(&s->loc[s->aborting_locty],
375                         TPM_TIS_STS_COMMAND_READY);
376         tpm_tis_raise_irq(s, s->aborting_locty, TPM_TIS_INT_COMMAND_READY);
377     }
378 
379     /* locality after abort is another one than the current one */
380     tpm_tis_new_active_locality(s, s->next_locty);
381 
382     s->next_locty = TPM_TIS_NO_LOCALITY;
383     /* nobody's aborting a command anymore */
384     s->aborting_locty = TPM_TIS_NO_LOCALITY;
385 }
386 
387 /* prepare aborting current command */
388 static void tpm_tis_prep_abort(TPMState *s, uint8_t locty, uint8_t newlocty)
389 {
390     uint8_t busy_locty;
391 
392     s->aborting_locty = locty;
393     s->next_locty = newlocty;  /* locality after successful abort */
394 
395     /*
396      * only abort a command using an interrupt if currently executing
397      * a command AND if there's a valid connection to the vTPM.
398      */
399     for (busy_locty = 0; busy_locty < TPM_TIS_NUM_LOCALITIES; busy_locty++) {
400         if (s->loc[busy_locty].state == TPM_TIS_STATE_EXECUTION) {
401             /*
402              * request the backend to cancel. Some backends may not
403              * support it
404              */
405             tpm_backend_cancel_cmd(s->be_driver);
406             return;
407         }
408     }
409 
410     tpm_tis_abort(s, locty);
411 }
412 
413 static void tpm_tis_receive_bh(void *opaque)
414 {
415     TPMState *s = opaque;
416     uint8_t locty = s->cmd.locty;
417 
418     tpm_tis_sts_set(&s->loc[locty],
419                     TPM_TIS_STS_VALID | TPM_TIS_STS_DATA_AVAILABLE);
420     s->loc[locty].state = TPM_TIS_STATE_COMPLETION;
421     s->loc[locty].r_offset = 0;
422     s->loc[locty].w_offset = 0;
423 
424     tpm_tis_show_buffer(&s->loc[locty].r_buffer, "tpm_tis: From TPM");
425 
426     if (TPM_TIS_IS_VALID_LOCTY(s->next_locty)) {
427         tpm_tis_abort(s, locty);
428     }
429 
430     tpm_tis_raise_irq(s, locty,
431                       TPM_TIS_INT_DATA_AVAILABLE | TPM_TIS_INT_STS_VALID);
432 }
433 
434 static void tpm_tis_request_completed(TPMIf *ti)
435 {
436     TPMState *s = TPM(ti);
437 
438     bool is_selftest_done = s->cmd.selftest_done;
439     uint8_t locty = s->cmd.locty;
440     uint8_t l;
441 
442     if (is_selftest_done) {
443         for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
444             s->loc[locty].sts |= TPM_TIS_STS_SELFTEST_DONE;
445         }
446     }
447 
448     qemu_bh_schedule(s->bh);
449 }
450 
451 /*
452  * Read a byte of response data
453  */
454 static uint32_t tpm_tis_data_read(TPMState *s, uint8_t locty)
455 {
456     uint32_t ret = TPM_TIS_NO_DATA_BYTE;
457     uint16_t len;
458 
459     if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
460         len = tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer);
461 
462         ret = s->loc[locty].r_buffer.buffer[s->loc[locty].r_offset++];
463         if (s->loc[locty].r_offset >= len) {
464             /* got last byte */
465             tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
466             tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
467         }
468         DPRINTF("tpm_tis: tpm_tis_data_read byte 0x%02x   [%d]\n",
469                 ret, s->loc[locty].r_offset - 1);
470     }
471 
472     return ret;
473 }
474 
475 #ifdef DEBUG_TIS
476 static void tpm_tis_dump_state(void *opaque, hwaddr addr)
477 {
478     static const unsigned regs[] = {
479         TPM_TIS_REG_ACCESS,
480         TPM_TIS_REG_INT_ENABLE,
481         TPM_TIS_REG_INT_VECTOR,
482         TPM_TIS_REG_INT_STATUS,
483         TPM_TIS_REG_INTF_CAPABILITY,
484         TPM_TIS_REG_STS,
485         TPM_TIS_REG_DID_VID,
486         TPM_TIS_REG_RID,
487         0xfff};
488     int idx;
489     uint8_t locty = tpm_tis_locality_from_addr(addr);
490     hwaddr base = addr & ~0xfff;
491     TPMState *s = opaque;
492 
493     DPRINTF("tpm_tis: active locality      : %d\n"
494             "tpm_tis: state of locality %d : %d\n"
495             "tpm_tis: register dump:\n",
496             s->active_locty,
497             locty, s->loc[locty].state);
498 
499     for (idx = 0; regs[idx] != 0xfff; idx++) {
500         DPRINTF("tpm_tis: 0x%04x : 0x%08x\n", regs[idx],
501                 (int)tpm_tis_mmio_read(opaque, base + regs[idx], 4));
502     }
503 
504     DPRINTF("tpm_tis: read offset   : %d\n"
505             "tpm_tis: result buffer : ",
506             s->loc[locty].r_offset);
507     for (idx = 0;
508          idx < tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer);
509          idx++) {
510         DPRINTF("%c%02x%s",
511                 s->loc[locty].r_offset == idx ? '>' : ' ',
512                 s->loc[locty].r_buffer.buffer[idx],
513                 ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
514     }
515     DPRINTF("\n"
516             "tpm_tis: write offset  : %d\n"
517             "tpm_tis: request buffer: ",
518             s->loc[locty].w_offset);
519     for (idx = 0;
520          idx < tpm_tis_get_size_from_buffer(&s->loc[locty].w_buffer);
521          idx++) {
522         DPRINTF("%c%02x%s",
523                 s->loc[locty].w_offset == idx ? '>' : ' ',
524                 s->loc[locty].w_buffer.buffer[idx],
525                 ((idx & 0xf) == 0xf) ? "\ntpm_tis:                 " : "");
526     }
527     DPRINTF("\n");
528 }
529 #endif
530 
531 /*
532  * Read a register of the TIS interface
533  * See specs pages 33-63 for description of the registers
534  */
535 static uint64_t tpm_tis_mmio_read(void *opaque, hwaddr addr,
536                                   unsigned size)
537 {
538     TPMState *s = opaque;
539     uint16_t offset = addr & 0xffc;
540     uint8_t shift = (addr & 0x3) * 8;
541     uint32_t val = 0xffffffff;
542     uint8_t locty = tpm_tis_locality_from_addr(addr);
543     uint32_t avail;
544     uint8_t v;
545 
546     if (tpm_backend_had_startup_error(s->be_driver)) {
547         return 0;
548     }
549 
550     switch (offset) {
551     case TPM_TIS_REG_ACCESS:
552         /* never show the SEIZE flag even though we use it internally */
553         val = s->loc[locty].access & ~TPM_TIS_ACCESS_SEIZE;
554         /* the pending flag is always calculated */
555         if (tpm_tis_check_request_use_except(s, locty)) {
556             val |= TPM_TIS_ACCESS_PENDING_REQUEST;
557         }
558         val |= !tpm_backend_get_tpm_established_flag(s->be_driver);
559         break;
560     case TPM_TIS_REG_INT_ENABLE:
561         val = s->loc[locty].inte;
562         break;
563     case TPM_TIS_REG_INT_VECTOR:
564         val = s->irq_num;
565         break;
566     case TPM_TIS_REG_INT_STATUS:
567         val = s->loc[locty].ints;
568         break;
569     case TPM_TIS_REG_INTF_CAPABILITY:
570         switch (s->be_tpm_version) {
571         case TPM_VERSION_UNSPEC:
572             val = 0;
573             break;
574         case TPM_VERSION_1_2:
575             val = TPM_TIS_CAPABILITIES_SUPPORTED1_3;
576             break;
577         case TPM_VERSION_2_0:
578             val = TPM_TIS_CAPABILITIES_SUPPORTED2_0;
579             break;
580         }
581         break;
582     case TPM_TIS_REG_STS:
583         if (s->active_locty == locty) {
584             if ((s->loc[locty].sts & TPM_TIS_STS_DATA_AVAILABLE)) {
585                 val = TPM_TIS_BURST_COUNT(
586                        tpm_tis_get_size_from_buffer(&s->loc[locty].r_buffer)
587                        - s->loc[locty].r_offset) | s->loc[locty].sts;
588             } else {
589                 avail = s->loc[locty].w_buffer.size
590                         - s->loc[locty].w_offset;
591                 /*
592                  * byte-sized reads should not return 0x00 for 0x100
593                  * available bytes.
594                  */
595                 if (size == 1 && avail > 0xff) {
596                     avail = 0xff;
597                 }
598                 val = TPM_TIS_BURST_COUNT(avail) | s->loc[locty].sts;
599             }
600         }
601         break;
602     case TPM_TIS_REG_DATA_FIFO:
603     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
604         if (s->active_locty == locty) {
605             if (size > 4 - (addr & 0x3)) {
606                 /* prevent access beyond FIFO */
607                 size = 4 - (addr & 0x3);
608             }
609             val = 0;
610             shift = 0;
611             while (size > 0) {
612                 switch (s->loc[locty].state) {
613                 case TPM_TIS_STATE_COMPLETION:
614                     v = tpm_tis_data_read(s, locty);
615                     break;
616                 default:
617                     v = TPM_TIS_NO_DATA_BYTE;
618                     break;
619                 }
620                 val |= (v << shift);
621                 shift += 8;
622                 size--;
623             }
624             shift = 0; /* no more adjustments */
625         }
626         break;
627     case TPM_TIS_REG_INTERFACE_ID:
628         val = s->loc[locty].iface_id;
629         break;
630     case TPM_TIS_REG_DID_VID:
631         val = (TPM_TIS_TPM_DID << 16) | TPM_TIS_TPM_VID;
632         break;
633     case TPM_TIS_REG_RID:
634         val = TPM_TIS_TPM_RID;
635         break;
636 #ifdef DEBUG_TIS
637     case TPM_TIS_REG_DEBUG:
638         tpm_tis_dump_state(opaque, addr);
639         break;
640 #endif
641     }
642 
643     if (shift) {
644         val >>= shift;
645     }
646 
647     DPRINTF("tpm_tis:  read.%u(%08x) = %08x\n", size, (int)addr, (int)val);
648 
649     return val;
650 }
651 
652 /*
653  * Write a value to a register of the TIS interface
654  * See specs pages 33-63 for description of the registers
655  */
656 static void tpm_tis_mmio_write(void *opaque, hwaddr addr,
657                                uint64_t val, unsigned size)
658 {
659     TPMState *s = opaque;
660     uint16_t off = addr & 0xffc;
661     uint8_t shift = (addr & 0x3) * 8;
662     uint8_t locty = tpm_tis_locality_from_addr(addr);
663     uint8_t active_locty, l;
664     int c, set_new_locty = 1;
665     uint16_t len;
666     uint32_t mask = (size == 1) ? 0xff : ((size == 2) ? 0xffff : ~0);
667 
668     DPRINTF("tpm_tis: write.%u(%08x) = %08x\n", size, (int)addr, (int)val);
669 
670     if (locty == 4) {
671         DPRINTF("tpm_tis: Access to locality 4 only allowed from hardware\n");
672         return;
673     }
674 
675     if (tpm_backend_had_startup_error(s->be_driver)) {
676         return;
677     }
678 
679     val &= mask;
680 
681     if (shift) {
682         val <<= shift;
683         mask <<= shift;
684     }
685 
686     mask ^= 0xffffffff;
687 
688     switch (off) {
689     case TPM_TIS_REG_ACCESS:
690 
691         if ((val & TPM_TIS_ACCESS_SEIZE)) {
692             val &= ~(TPM_TIS_ACCESS_REQUEST_USE |
693                      TPM_TIS_ACCESS_ACTIVE_LOCALITY);
694         }
695 
696         active_locty = s->active_locty;
697 
698         if ((val & TPM_TIS_ACCESS_ACTIVE_LOCALITY)) {
699             /* give up locality if currently owned */
700             if (s->active_locty == locty) {
701                 DPRINTF("tpm_tis: Releasing locality %d\n", locty);
702 
703                 uint8_t newlocty = TPM_TIS_NO_LOCALITY;
704                 /* anybody wants the locality ? */
705                 for (c = TPM_TIS_NUM_LOCALITIES - 1; c >= 0; c--) {
706                     if ((s->loc[c].access & TPM_TIS_ACCESS_REQUEST_USE)) {
707                         DPRINTF("tpm_tis: Locality %d requests use.\n", c);
708                         newlocty = c;
709                         break;
710                     }
711                 }
712                 DPRINTF("tpm_tis: TPM_TIS_ACCESS_ACTIVE_LOCALITY: "
713                         "Next active locality: %d\n",
714                         newlocty);
715 
716                 if (TPM_TIS_IS_VALID_LOCTY(newlocty)) {
717                     set_new_locty = 0;
718                     tpm_tis_prep_abort(s, locty, newlocty);
719                 } else {
720                     active_locty = TPM_TIS_NO_LOCALITY;
721                 }
722             } else {
723                 /* not currently the owner; clear a pending request */
724                 s->loc[locty].access &= ~TPM_TIS_ACCESS_REQUEST_USE;
725             }
726         }
727 
728         if ((val & TPM_TIS_ACCESS_BEEN_SEIZED)) {
729             s->loc[locty].access &= ~TPM_TIS_ACCESS_BEEN_SEIZED;
730         }
731 
732         if ((val & TPM_TIS_ACCESS_SEIZE)) {
733             /*
734              * allow seize if a locality is active and the requesting
735              * locality is higher than the one that's active
736              * OR
737              * allow seize for requesting locality if no locality is
738              * active
739              */
740             while ((TPM_TIS_IS_VALID_LOCTY(s->active_locty) &&
741                     locty > s->active_locty) ||
742                     !TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
743                 bool higher_seize = FALSE;
744 
745                 /* already a pending SEIZE ? */
746                 if ((s->loc[locty].access & TPM_TIS_ACCESS_SEIZE)) {
747                     break;
748                 }
749 
750                 /* check for ongoing seize by a higher locality */
751                 for (l = locty + 1; l < TPM_TIS_NUM_LOCALITIES; l++) {
752                     if ((s->loc[l].access & TPM_TIS_ACCESS_SEIZE)) {
753                         higher_seize = TRUE;
754                         break;
755                     }
756                 }
757 
758                 if (higher_seize) {
759                     break;
760                 }
761 
762                 /* cancel any seize by a lower locality */
763                 for (l = 0; l < locty - 1; l++) {
764                     s->loc[l].access &= ~TPM_TIS_ACCESS_SEIZE;
765                 }
766 
767                 s->loc[locty].access |= TPM_TIS_ACCESS_SEIZE;
768                 DPRINTF("tpm_tis: TPM_TIS_ACCESS_SEIZE: "
769                         "Locality %d seized from locality %d\n",
770                         locty, s->active_locty);
771                 DPRINTF("tpm_tis: TPM_TIS_ACCESS_SEIZE: Initiating abort.\n");
772                 set_new_locty = 0;
773                 tpm_tis_prep_abort(s, s->active_locty, locty);
774                 break;
775             }
776         }
777 
778         if ((val & TPM_TIS_ACCESS_REQUEST_USE)) {
779             if (s->active_locty != locty) {
780                 if (TPM_TIS_IS_VALID_LOCTY(s->active_locty)) {
781                     s->loc[locty].access |= TPM_TIS_ACCESS_REQUEST_USE;
782                 } else {
783                     /* no locality active -> make this one active now */
784                     active_locty = locty;
785                 }
786             }
787         }
788 
789         if (set_new_locty) {
790             tpm_tis_new_active_locality(s, active_locty);
791         }
792 
793         break;
794     case TPM_TIS_REG_INT_ENABLE:
795         if (s->active_locty != locty) {
796             break;
797         }
798 
799         s->loc[locty].inte &= mask;
800         s->loc[locty].inte |= (val & (TPM_TIS_INT_ENABLED |
801                                         TPM_TIS_INT_POLARITY_MASK |
802                                         TPM_TIS_INTERRUPTS_SUPPORTED));
803         break;
804     case TPM_TIS_REG_INT_VECTOR:
805         /* hard wired -- ignore */
806         break;
807     case TPM_TIS_REG_INT_STATUS:
808         if (s->active_locty != locty) {
809             break;
810         }
811 
812         /* clearing of interrupt flags */
813         if (((val & TPM_TIS_INTERRUPTS_SUPPORTED)) &&
814             (s->loc[locty].ints & TPM_TIS_INTERRUPTS_SUPPORTED)) {
815             s->loc[locty].ints &= ~val;
816             if (s->loc[locty].ints == 0) {
817                 qemu_irq_lower(s->irq);
818                 DPRINTF("tpm_tis: Lowering IRQ\n");
819             }
820         }
821         s->loc[locty].ints &= ~(val & TPM_TIS_INTERRUPTS_SUPPORTED);
822         break;
823     case TPM_TIS_REG_STS:
824         if (s->active_locty != locty) {
825             break;
826         }
827 
828         if (s->be_tpm_version == TPM_VERSION_2_0) {
829             /* some flags that are only supported for TPM 2 */
830             if (val & TPM_TIS_STS_COMMAND_CANCEL) {
831                 if (s->loc[locty].state == TPM_TIS_STATE_EXECUTION) {
832                     /*
833                      * request the backend to cancel. Some backends may not
834                      * support it
835                      */
836                     tpm_backend_cancel_cmd(s->be_driver);
837                 }
838             }
839 
840             if (val & TPM_TIS_STS_RESET_ESTABLISHMENT_BIT) {
841                 if (locty == 3 || locty == 4) {
842                     tpm_backend_reset_tpm_established_flag(s->be_driver, locty);
843                 }
844             }
845         }
846 
847         val &= (TPM_TIS_STS_COMMAND_READY | TPM_TIS_STS_TPM_GO |
848                 TPM_TIS_STS_RESPONSE_RETRY);
849 
850         if (val == TPM_TIS_STS_COMMAND_READY) {
851             switch (s->loc[locty].state) {
852 
853             case TPM_TIS_STATE_READY:
854                 s->loc[locty].w_offset = 0;
855                 s->loc[locty].r_offset = 0;
856             break;
857 
858             case TPM_TIS_STATE_IDLE:
859                 tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_COMMAND_READY);
860                 s->loc[locty].state = TPM_TIS_STATE_READY;
861                 tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
862             break;
863 
864             case TPM_TIS_STATE_EXECUTION:
865             case TPM_TIS_STATE_RECEPTION:
866                 /* abort currently running command */
867                 DPRINTF("tpm_tis: %s: Initiating abort.\n",
868                         __func__);
869                 tpm_tis_prep_abort(s, locty, locty);
870             break;
871 
872             case TPM_TIS_STATE_COMPLETION:
873                 s->loc[locty].w_offset = 0;
874                 s->loc[locty].r_offset = 0;
875                 /* shortcut to ready state with C/R set */
876                 s->loc[locty].state = TPM_TIS_STATE_READY;
877                 if (!(s->loc[locty].sts & TPM_TIS_STS_COMMAND_READY)) {
878                     tpm_tis_sts_set(&s->loc[locty],
879                                     TPM_TIS_STS_COMMAND_READY);
880                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_COMMAND_READY);
881                 }
882                 s->loc[locty].sts &= ~(TPM_TIS_STS_DATA_AVAILABLE);
883             break;
884 
885             }
886         } else if (val == TPM_TIS_STS_TPM_GO) {
887             switch (s->loc[locty].state) {
888             case TPM_TIS_STATE_RECEPTION:
889                 if ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) == 0) {
890                     tpm_tis_tpm_send(s, locty);
891                 }
892                 break;
893             default:
894                 /* ignore */
895                 break;
896             }
897         } else if (val == TPM_TIS_STS_RESPONSE_RETRY) {
898             switch (s->loc[locty].state) {
899             case TPM_TIS_STATE_COMPLETION:
900                 s->loc[locty].r_offset = 0;
901                 tpm_tis_sts_set(&s->loc[locty],
902                                 TPM_TIS_STS_VALID|
903                                 TPM_TIS_STS_DATA_AVAILABLE);
904                 break;
905             default:
906                 /* ignore */
907                 break;
908             }
909         }
910         break;
911     case TPM_TIS_REG_DATA_FIFO:
912     case TPM_TIS_REG_DATA_XFIFO ... TPM_TIS_REG_DATA_XFIFO_END:
913         /* data fifo */
914         if (s->active_locty != locty) {
915             break;
916         }
917 
918         if (s->loc[locty].state == TPM_TIS_STATE_IDLE ||
919             s->loc[locty].state == TPM_TIS_STATE_EXECUTION ||
920             s->loc[locty].state == TPM_TIS_STATE_COMPLETION) {
921             /* drop the byte */
922         } else {
923             DPRINTF("tpm_tis: Data to send to TPM: %08x (size=%d)\n",
924                     (int)val, size);
925             if (s->loc[locty].state == TPM_TIS_STATE_READY) {
926                 s->loc[locty].state = TPM_TIS_STATE_RECEPTION;
927                 tpm_tis_sts_set(&s->loc[locty],
928                                 TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
929             }
930 
931             val >>= shift;
932             if (size > 4 - (addr & 0x3)) {
933                 /* prevent access beyond FIFO */
934                 size = 4 - (addr & 0x3);
935             }
936 
937             while ((s->loc[locty].sts & TPM_TIS_STS_EXPECT) && size > 0) {
938                 if (s->loc[locty].w_offset < s->loc[locty].w_buffer.size) {
939                     s->loc[locty].w_buffer.
940                         buffer[s->loc[locty].w_offset++] = (uint8_t)val;
941                     val >>= 8;
942                     size--;
943                 } else {
944                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
945                 }
946             }
947 
948             /* check for complete packet */
949             if (s->loc[locty].w_offset > 5 &&
950                 (s->loc[locty].sts & TPM_TIS_STS_EXPECT)) {
951                 /* we have a packet length - see if we have all of it */
952                 bool need_irq = !(s->loc[locty].sts & TPM_TIS_STS_VALID);
953 
954                 len = tpm_tis_get_size_from_buffer(&s->loc[locty].w_buffer);
955                 if (len > s->loc[locty].w_offset) {
956                     tpm_tis_sts_set(&s->loc[locty],
957                                     TPM_TIS_STS_EXPECT | TPM_TIS_STS_VALID);
958                 } else {
959                     /* packet complete */
960                     tpm_tis_sts_set(&s->loc[locty], TPM_TIS_STS_VALID);
961                 }
962                 if (need_irq) {
963                     tpm_tis_raise_irq(s, locty, TPM_TIS_INT_STS_VALID);
964                 }
965             }
966         }
967         break;
968     case TPM_TIS_REG_INTERFACE_ID:
969         if (val & TPM_TIS_IFACE_ID_INT_SEL_LOCK) {
970             for (l = 0; l < TPM_TIS_NUM_LOCALITIES; l++) {
971                 s->loc[l].iface_id |= TPM_TIS_IFACE_ID_INT_SEL_LOCK;
972             }
973         }
974         break;
975     }
976 }
977 
978 static const MemoryRegionOps tpm_tis_memory_ops = {
979     .read = tpm_tis_mmio_read,
980     .write = tpm_tis_mmio_write,
981     .endianness = DEVICE_LITTLE_ENDIAN,
982     .valid = {
983         .min_access_size = 1,
984         .max_access_size = 4,
985     },
986 };
987 
988 static int tpm_tis_do_startup_tpm(TPMState *s)
989 {
990     return tpm_backend_startup_tpm(s->be_driver);
991 }
992 
993 static void tpm_tis_realloc_buffer(TPMSizedBuffer *sb)
994 {
995     size_t wanted_size = 4096; /* Linux tpm.c buffer size */
996 
997     if (sb->size != wanted_size) {
998         sb->buffer = g_realloc(sb->buffer, wanted_size);
999         sb->size = wanted_size;
1000     }
1001 }
1002 
1003 /*
1004  * Get the TPMVersion of the backend device being used
1005  */
1006 TPMVersion tpm_tis_get_tpm_version(Object *obj)
1007 {
1008     TPMState *s = TPM(obj);
1009 
1010     if (tpm_backend_had_startup_error(s->be_driver)) {
1011         return TPM_VERSION_UNSPEC;
1012     }
1013 
1014     return tpm_backend_get_tpm_version(s->be_driver);
1015 }
1016 
1017 /*
1018  * This function is called when the machine starts, resets or due to
1019  * S3 resume.
1020  */
1021 static void tpm_tis_reset(DeviceState *dev)
1022 {
1023     TPMState *s = TPM(dev);
1024     int c;
1025 
1026     s->be_tpm_version = tpm_backend_get_tpm_version(s->be_driver);
1027 
1028     tpm_backend_reset(s->be_driver);
1029 
1030     s->active_locty = TPM_TIS_NO_LOCALITY;
1031     s->next_locty = TPM_TIS_NO_LOCALITY;
1032     s->aborting_locty = TPM_TIS_NO_LOCALITY;
1033 
1034     for (c = 0; c < TPM_TIS_NUM_LOCALITIES; c++) {
1035         s->loc[c].access = TPM_TIS_ACCESS_TPM_REG_VALID_STS;
1036         switch (s->be_tpm_version) {
1037         case TPM_VERSION_UNSPEC:
1038             break;
1039         case TPM_VERSION_1_2:
1040             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY1_2;
1041             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS1_3;
1042             break;
1043         case TPM_VERSION_2_0:
1044             s->loc[c].sts = TPM_TIS_STS_TPM_FAMILY2_0;
1045             s->loc[c].iface_id = TPM_TIS_IFACE_ID_SUPPORTED_FLAGS2_0;
1046             break;
1047         }
1048         s->loc[c].inte = TPM_TIS_INT_POLARITY_LOW_LEVEL;
1049         s->loc[c].ints = 0;
1050         s->loc[c].state = TPM_TIS_STATE_IDLE;
1051 
1052         s->loc[c].w_offset = 0;
1053         tpm_tis_realloc_buffer(&s->loc[c].w_buffer);
1054         s->loc[c].r_offset = 0;
1055         tpm_tis_realloc_buffer(&s->loc[c].r_buffer);
1056     }
1057 
1058     tpm_tis_do_startup_tpm(s);
1059 }
1060 
1061 static const VMStateDescription vmstate_tpm_tis = {
1062     .name = "tpm",
1063     .unmigratable = 1,
1064 };
1065 
1066 static Property tpm_tis_properties[] = {
1067     DEFINE_PROP_UINT32("irq", TPMState, irq_num, TPM_TIS_IRQ),
1068     DEFINE_PROP_STRING("tpmdev", TPMState, backend),
1069     DEFINE_PROP_END_OF_LIST(),
1070 };
1071 
1072 static void tpm_tis_realizefn(DeviceState *dev, Error **errp)
1073 {
1074     TPMState *s = TPM(dev);
1075 
1076     s->be_driver = qemu_find_tpm(s->backend);
1077     if (!s->be_driver) {
1078         error_setg(errp, "tpm_tis: backend driver with id %s could not be "
1079                    "found", s->backend);
1080         return;
1081     }
1082 
1083     s->be_driver->fe_model = TPM_MODEL_TPM_TIS;
1084 
1085     if (tpm_backend_init(s->be_driver, TPM_IF(s))) {
1086         error_setg(errp, "tpm_tis: backend driver with id %s could not be "
1087                    "initialized", s->backend);
1088         return;
1089     }
1090 
1091     if (s->irq_num > 15) {
1092         error_setg(errp, "tpm_tis: IRQ %d for TPM TIS is outside valid range "
1093                    "of 0 to 15", s->irq_num);
1094         return;
1095     }
1096 
1097     s->bh = qemu_bh_new(tpm_tis_receive_bh, s);
1098 
1099     isa_init_irq(&s->busdev, &s->irq, s->irq_num);
1100 
1101     memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
1102                                 TPM_TIS_ADDR_BASE, &s->mmio);
1103 }
1104 
1105 static void tpm_tis_initfn(Object *obj)
1106 {
1107     TPMState *s = TPM(obj);
1108 
1109     memory_region_init_io(&s->mmio, OBJECT(s), &tpm_tis_memory_ops,
1110                           s, "tpm-tis-mmio",
1111                           TPM_TIS_NUM_LOCALITIES << TPM_TIS_LOCALITY_SHIFT);
1112 }
1113 
1114 static void tpm_tis_class_init(ObjectClass *klass, void *data)
1115 {
1116     DeviceClass *dc = DEVICE_CLASS(klass);
1117     TPMIfClass *tc = TPM_IF_CLASS(klass);
1118 
1119     dc->realize = tpm_tis_realizefn;
1120     dc->props = tpm_tis_properties;
1121     dc->reset = tpm_tis_reset;
1122     dc->vmsd  = &vmstate_tpm_tis;
1123     tc->request_completed = tpm_tis_request_completed;
1124 }
1125 
1126 static const TypeInfo tpm_tis_info = {
1127     .name = TYPE_TPM_TIS,
1128     .parent = TYPE_ISA_DEVICE,
1129     .instance_size = sizeof(TPMState),
1130     .instance_init = tpm_tis_initfn,
1131     .class_init  = tpm_tis_class_init,
1132     .interfaces = (InterfaceInfo[]) {
1133         { TYPE_TPM_IF },
1134         { }
1135     }
1136 };
1137 
1138 static void tpm_tis_register(void)
1139 {
1140     type_register_static(&tpm_tis_info);
1141     tpm_register_model(TPM_MODEL_TPM_TIS);
1142 }
1143 
1144 type_init(tpm_tis_register)
1145