xref: /openbmc/qemu/hw/misc/tz-mpc.c (revision 37677d7d)
1 /*
2  * ARM AHB5 TrustZone Memory Protection Controller emulation
3  *
4  * Copyright (c) 2018 Linaro Limited
5  * Written by Peter Maydell
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 or
9  * (at your option) any later version.
10  */
11 
12 #include "qemu/osdep.h"
13 #include "qemu/log.h"
14 #include "qemu/module.h"
15 #include "qapi/error.h"
16 #include "trace.h"
17 #include "hw/sysbus.h"
18 #include "hw/registerfields.h"
19 #include "hw/misc/tz-mpc.h"
20 
21 /* Our IOMMU has two IOMMU indexes, one for secure transactions and one for
22  * non-secure transactions.
23  */
24 enum {
25     IOMMU_IDX_S,
26     IOMMU_IDX_NS,
27     IOMMU_NUM_INDEXES,
28 };
29 
30 /* Config registers */
31 REG32(CTRL, 0x00)
32     FIELD(CTRL, SEC_RESP, 4, 1)
33     FIELD(CTRL, AUTOINC, 8, 1)
34     FIELD(CTRL, LOCKDOWN, 31, 1)
35 REG32(BLK_MAX, 0x10)
36 REG32(BLK_CFG, 0x14)
37 REG32(BLK_IDX, 0x18)
38 REG32(BLK_LUT, 0x1c)
39 REG32(INT_STAT, 0x20)
40     FIELD(INT_STAT, IRQ, 0, 1)
41 REG32(INT_CLEAR, 0x24)
42     FIELD(INT_CLEAR, IRQ, 0, 1)
43 REG32(INT_EN, 0x28)
44     FIELD(INT_EN, IRQ, 0, 1)
45 REG32(INT_INFO1, 0x2c)
46 REG32(INT_INFO2, 0x30)
47     FIELD(INT_INFO2, HMASTER, 0, 16)
48     FIELD(INT_INFO2, HNONSEC, 16, 1)
49     FIELD(INT_INFO2, CFG_NS, 17, 1)
50 REG32(INT_SET, 0x34)
51     FIELD(INT_SET, IRQ, 0, 1)
52 REG32(PIDR4, 0xfd0)
53 REG32(PIDR5, 0xfd4)
54 REG32(PIDR6, 0xfd8)
55 REG32(PIDR7, 0xfdc)
56 REG32(PIDR0, 0xfe0)
57 REG32(PIDR1, 0xfe4)
58 REG32(PIDR2, 0xfe8)
59 REG32(PIDR3, 0xfec)
60 REG32(CIDR0, 0xff0)
61 REG32(CIDR1, 0xff4)
62 REG32(CIDR2, 0xff8)
63 REG32(CIDR3, 0xffc)
64 
65 static const uint8_t tz_mpc_idregs[] = {
66     0x04, 0x00, 0x00, 0x00,
67     0x60, 0xb8, 0x1b, 0x00,
68     0x0d, 0xf0, 0x05, 0xb1,
69 };
70 
71 static void tz_mpc_irq_update(TZMPC *s)
72 {
73     qemu_set_irq(s->irq, s->int_stat && s->int_en);
74 }
75 
76 static void tz_mpc_iommu_notify(TZMPC *s, uint32_t lutidx,
77                                 uint32_t oldlut, uint32_t newlut)
78 {
79     /* Called when the LUT word at lutidx has changed from oldlut to newlut;
80      * must call the IOMMU notifiers for the changed blocks.
81      */
82     IOMMUTLBEntry entry = {
83         .addr_mask = s->blocksize - 1,
84     };
85     hwaddr addr = lutidx * s->blocksize * 32;
86     int i;
87 
88     for (i = 0; i < 32; i++, addr += s->blocksize) {
89         bool block_is_ns;
90 
91         if (!((oldlut ^ newlut) & (1 << i))) {
92             continue;
93         }
94         /* This changes the mappings for both the S and the NS space,
95          * so we need to do four notifies: an UNMAP then a MAP for each.
96          */
97         block_is_ns = newlut & (1 << i);
98 
99         trace_tz_mpc_iommu_notify(addr);
100         entry.iova = addr;
101         entry.translated_addr = addr;
102 
103         entry.perm = IOMMU_NONE;
104         memory_region_notify_iommu(&s->upstream, IOMMU_IDX_S, entry);
105         memory_region_notify_iommu(&s->upstream, IOMMU_IDX_NS, entry);
106 
107         entry.perm = IOMMU_RW;
108         if (block_is_ns) {
109             entry.target_as = &s->blocked_io_as;
110         } else {
111             entry.target_as = &s->downstream_as;
112         }
113         memory_region_notify_iommu(&s->upstream, IOMMU_IDX_S, entry);
114         if (block_is_ns) {
115             entry.target_as = &s->downstream_as;
116         } else {
117             entry.target_as = &s->blocked_io_as;
118         }
119         memory_region_notify_iommu(&s->upstream, IOMMU_IDX_NS, entry);
120     }
121 }
122 
123 static void tz_mpc_autoinc_idx(TZMPC *s, unsigned access_size)
124 {
125     /* Auto-increment BLK_IDX if necessary */
126     if (access_size == 4 && (s->ctrl & R_CTRL_AUTOINC_MASK)) {
127         s->blk_idx++;
128         s->blk_idx %= s->blk_max;
129     }
130 }
131 
132 static MemTxResult tz_mpc_reg_read(void *opaque, hwaddr addr,
133                                    uint64_t *pdata,
134                                    unsigned size, MemTxAttrs attrs)
135 {
136     TZMPC *s = TZ_MPC(opaque);
137     uint64_t r;
138     uint32_t offset = addr & ~0x3;
139 
140     if (!attrs.secure && offset < A_PIDR4) {
141         /* NS accesses can only see the ID registers */
142         qemu_log_mask(LOG_GUEST_ERROR,
143                       "TZ MPC register read: NS access to offset 0x%x\n",
144                       offset);
145         r = 0;
146         goto read_out;
147     }
148 
149     switch (offset) {
150     case A_CTRL:
151         r = s->ctrl;
152         break;
153     case A_BLK_MAX:
154         r = s->blk_max - 1;
155         break;
156     case A_BLK_CFG:
157         /* We are never in "init in progress state", so this just indicates
158          * the block size. s->blocksize == (1 << BLK_CFG + 5), so
159          * BLK_CFG == ctz32(s->blocksize) - 5
160          */
161         r = ctz32(s->blocksize) - 5;
162         break;
163     case A_BLK_IDX:
164         r = s->blk_idx;
165         break;
166     case A_BLK_LUT:
167         r = s->blk_lut[s->blk_idx];
168         tz_mpc_autoinc_idx(s, size);
169         break;
170     case A_INT_STAT:
171         r = s->int_stat;
172         break;
173     case A_INT_EN:
174         r = s->int_en;
175         break;
176     case A_INT_INFO1:
177         r = s->int_info1;
178         break;
179     case A_INT_INFO2:
180         r = s->int_info2;
181         break;
182     case A_PIDR4:
183     case A_PIDR5:
184     case A_PIDR6:
185     case A_PIDR7:
186     case A_PIDR0:
187     case A_PIDR1:
188     case A_PIDR2:
189     case A_PIDR3:
190     case A_CIDR0:
191     case A_CIDR1:
192     case A_CIDR2:
193     case A_CIDR3:
194         r = tz_mpc_idregs[(offset - A_PIDR4) / 4];
195         break;
196     case A_INT_CLEAR:
197     case A_INT_SET:
198         qemu_log_mask(LOG_GUEST_ERROR,
199                       "TZ MPC register read: write-only offset 0x%x\n",
200                       offset);
201         r = 0;
202         break;
203     default:
204         qemu_log_mask(LOG_GUEST_ERROR,
205                       "TZ MPC register read: bad offset 0x%x\n", offset);
206         r = 0;
207         break;
208     }
209 
210     if (size != 4) {
211         /* None of our registers are read-sensitive (except BLK_LUT,
212          * which can special case the "size not 4" case), so just
213          * pull the right bytes out of the word read result.
214          */
215         r = extract32(r, (addr & 3) * 8, size * 8);
216     }
217 
218 read_out:
219     trace_tz_mpc_reg_read(addr, r, size);
220     *pdata = r;
221     return MEMTX_OK;
222 }
223 
224 static MemTxResult tz_mpc_reg_write(void *opaque, hwaddr addr,
225                                     uint64_t value,
226                                     unsigned size, MemTxAttrs attrs)
227 {
228     TZMPC *s = TZ_MPC(opaque);
229     uint32_t offset = addr & ~0x3;
230 
231     trace_tz_mpc_reg_write(addr, value, size);
232 
233     if (!attrs.secure && offset < A_PIDR4) {
234         /* NS accesses can only see the ID registers */
235         qemu_log_mask(LOG_GUEST_ERROR,
236                       "TZ MPC register write: NS access to offset 0x%x\n",
237                       offset);
238         return MEMTX_OK;
239     }
240 
241     if (size != 4) {
242         /* Expand the byte or halfword write to a full word size.
243          * In most cases we can do this with zeroes; the exceptions
244          * are CTRL, BLK_IDX and BLK_LUT.
245          */
246         uint32_t oldval;
247 
248         switch (offset) {
249         case A_CTRL:
250             oldval = s->ctrl;
251             break;
252         case A_BLK_IDX:
253             oldval = s->blk_idx;
254             break;
255         case A_BLK_LUT:
256             oldval = s->blk_lut[s->blk_idx];
257             break;
258         default:
259             oldval = 0;
260             break;
261         }
262         value = deposit32(oldval, (addr & 3) * 8, size * 8, value);
263     }
264 
265     if ((s->ctrl & R_CTRL_LOCKDOWN_MASK) &&
266         (offset == A_CTRL || offset == A_BLK_LUT || offset == A_INT_EN)) {
267         /* Lockdown mode makes these three registers read-only, and
268          * the only way out of it is to reset the device.
269          */
270         qemu_log_mask(LOG_GUEST_ERROR, "TZ MPC register write to offset 0x%x "
271                       "while MPC is in lockdown mode\n", offset);
272         return MEMTX_OK;
273     }
274 
275     switch (offset) {
276     case A_CTRL:
277         /* We don't implement the 'data gating' feature so all other bits
278          * are reserved and we make them RAZ/WI.
279          */
280         s->ctrl = value & (R_CTRL_SEC_RESP_MASK |
281                            R_CTRL_AUTOINC_MASK |
282                            R_CTRL_LOCKDOWN_MASK);
283         break;
284     case A_BLK_IDX:
285         s->blk_idx = value % s->blk_max;
286         break;
287     case A_BLK_LUT:
288         tz_mpc_iommu_notify(s, s->blk_idx, s->blk_lut[s->blk_idx], value);
289         s->blk_lut[s->blk_idx] = value;
290         tz_mpc_autoinc_idx(s, size);
291         break;
292     case A_INT_CLEAR:
293         if (value & R_INT_CLEAR_IRQ_MASK) {
294             s->int_stat = 0;
295             tz_mpc_irq_update(s);
296         }
297         break;
298     case A_INT_EN:
299         s->int_en = value & R_INT_EN_IRQ_MASK;
300         tz_mpc_irq_update(s);
301         break;
302     case A_INT_SET:
303         if (value & R_INT_SET_IRQ_MASK) {
304             s->int_stat = R_INT_STAT_IRQ_MASK;
305             tz_mpc_irq_update(s);
306         }
307         break;
308     case A_PIDR4:
309     case A_PIDR5:
310     case A_PIDR6:
311     case A_PIDR7:
312     case A_PIDR0:
313     case A_PIDR1:
314     case A_PIDR2:
315     case A_PIDR3:
316     case A_CIDR0:
317     case A_CIDR1:
318     case A_CIDR2:
319     case A_CIDR3:
320         qemu_log_mask(LOG_GUEST_ERROR,
321                       "TZ MPC register write: read-only offset 0x%x\n", offset);
322         break;
323     default:
324         qemu_log_mask(LOG_GUEST_ERROR,
325                       "TZ MPC register write: bad offset 0x%x\n", offset);
326         break;
327     }
328 
329     return MEMTX_OK;
330 }
331 
332 static const MemoryRegionOps tz_mpc_reg_ops = {
333     .read_with_attrs = tz_mpc_reg_read,
334     .write_with_attrs = tz_mpc_reg_write,
335     .endianness = DEVICE_LITTLE_ENDIAN,
336     .valid.min_access_size = 1,
337     .valid.max_access_size = 4,
338     .impl.min_access_size = 1,
339     .impl.max_access_size = 4,
340 };
341 
342 static inline bool tz_mpc_cfg_ns(TZMPC *s, hwaddr addr)
343 {
344     /* Return the cfg_ns bit from the LUT for the specified address */
345     hwaddr blknum = addr / s->blocksize;
346     hwaddr blkword = blknum / 32;
347     uint32_t blkbit = 1U << (blknum % 32);
348 
349     /* This would imply the address was larger than the size we
350      * defined this memory region to be, so it can't happen.
351      */
352     assert(blkword < s->blk_max);
353     return s->blk_lut[blkword] & blkbit;
354 }
355 
356 static MemTxResult tz_mpc_handle_block(TZMPC *s, hwaddr addr, MemTxAttrs attrs)
357 {
358     /* Handle a blocked transaction: raise IRQ, capture info, etc */
359     if (!s->int_stat) {
360         /* First blocked transfer: capture information into INT_INFO1 and
361          * INT_INFO2. Subsequent transfers are still blocked but don't
362          * capture information until the guest clears the interrupt.
363          */
364 
365         s->int_info1 = addr;
366         s->int_info2 = 0;
367         s->int_info2 = FIELD_DP32(s->int_info2, INT_INFO2, HMASTER,
368                                   attrs.requester_id & 0xffff);
369         s->int_info2 = FIELD_DP32(s->int_info2, INT_INFO2, HNONSEC,
370                                   ~attrs.secure);
371         s->int_info2 = FIELD_DP32(s->int_info2, INT_INFO2, CFG_NS,
372                                   tz_mpc_cfg_ns(s, addr));
373         s->int_stat |= R_INT_STAT_IRQ_MASK;
374         tz_mpc_irq_update(s);
375     }
376 
377     /* Generate bus error if desired; otherwise RAZ/WI */
378     return (s->ctrl & R_CTRL_SEC_RESP_MASK) ? MEMTX_ERROR : MEMTX_OK;
379 }
380 
381 /* Accesses only reach these read and write functions if the MPC is
382  * blocking them; non-blocked accesses go directly to the downstream
383  * memory region without passing through this code.
384  */
385 static MemTxResult tz_mpc_mem_blocked_read(void *opaque, hwaddr addr,
386                                            uint64_t *pdata,
387                                            unsigned size, MemTxAttrs attrs)
388 {
389     TZMPC *s = TZ_MPC(opaque);
390 
391     trace_tz_mpc_mem_blocked_read(addr, size, attrs.secure);
392 
393     *pdata = 0;
394     return tz_mpc_handle_block(s, addr, attrs);
395 }
396 
397 static MemTxResult tz_mpc_mem_blocked_write(void *opaque, hwaddr addr,
398                                             uint64_t value,
399                                             unsigned size, MemTxAttrs attrs)
400 {
401     TZMPC *s = TZ_MPC(opaque);
402 
403     trace_tz_mpc_mem_blocked_write(addr, value, size, attrs.secure);
404 
405     return tz_mpc_handle_block(s, addr, attrs);
406 }
407 
408 static const MemoryRegionOps tz_mpc_mem_blocked_ops = {
409     .read_with_attrs = tz_mpc_mem_blocked_read,
410     .write_with_attrs = tz_mpc_mem_blocked_write,
411     .endianness = DEVICE_LITTLE_ENDIAN,
412     .valid.min_access_size = 1,
413     .valid.max_access_size = 8,
414     .impl.min_access_size = 1,
415     .impl.max_access_size = 8,
416 };
417 
418 static IOMMUTLBEntry tz_mpc_translate(IOMMUMemoryRegion *iommu,
419                                       hwaddr addr, IOMMUAccessFlags flags,
420                                       int iommu_idx)
421 {
422     TZMPC *s = TZ_MPC(container_of(iommu, TZMPC, upstream));
423     bool ok;
424 
425     IOMMUTLBEntry ret = {
426         .iova = addr & ~(s->blocksize - 1),
427         .translated_addr = addr & ~(s->blocksize - 1),
428         .addr_mask = s->blocksize - 1,
429         .perm = IOMMU_RW,
430     };
431 
432     /* Look at the per-block configuration for this address, and
433      * return a TLB entry directing the transaction at either
434      * downstream_as or blocked_io_as, as appropriate.
435      * If the LUT cfg_ns bit is 1, only non-secure transactions
436      * may pass. If the bit is 0, only secure transactions may pass.
437      */
438     ok = tz_mpc_cfg_ns(s, addr) == (iommu_idx == IOMMU_IDX_NS);
439 
440     trace_tz_mpc_translate(addr, flags,
441                            iommu_idx == IOMMU_IDX_S ? "S" : "NS",
442                            ok ? "pass" : "block");
443 
444     ret.target_as = ok ? &s->downstream_as : &s->blocked_io_as;
445     return ret;
446 }
447 
448 static int tz_mpc_attrs_to_index(IOMMUMemoryRegion *iommu, MemTxAttrs attrs)
449 {
450     /* We treat unspecified attributes like secure. Transactions with
451      * unspecified attributes come from places like
452      * rom_reset() for initial image load, and we want
453      * those to pass through the from-reset "everything is secure" config.
454      * All the real during-emulation transactions from the CPU will
455      * specify attributes.
456      */
457     return (attrs.unspecified || attrs.secure) ? IOMMU_IDX_S : IOMMU_IDX_NS;
458 }
459 
460 static int tz_mpc_num_indexes(IOMMUMemoryRegion *iommu)
461 {
462     return IOMMU_NUM_INDEXES;
463 }
464 
465 static void tz_mpc_reset(DeviceState *dev)
466 {
467     TZMPC *s = TZ_MPC(dev);
468 
469     s->ctrl = 0x00000100;
470     s->blk_idx = 0;
471     s->int_stat = 0;
472     s->int_en = 1;
473     s->int_info1 = 0;
474     s->int_info2 = 0;
475 
476     memset(s->blk_lut, 0, s->blk_max * sizeof(uint32_t));
477 }
478 
479 static void tz_mpc_init(Object *obj)
480 {
481     DeviceState *dev = DEVICE(obj);
482     TZMPC *s = TZ_MPC(obj);
483 
484     qdev_init_gpio_out_named(dev, &s->irq, "irq", 1);
485 }
486 
487 static void tz_mpc_realize(DeviceState *dev, Error **errp)
488 {
489     Object *obj = OBJECT(dev);
490     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
491     TZMPC *s = TZ_MPC(dev);
492     uint64_t size;
493 
494     /* We can't create the upstream end of the port until realize,
495      * as we don't know the size of the MR used as the downstream until then.
496      * We insist on having a downstream, to avoid complicating the code
497      * with handling the "don't know how big this is" case. It's easy
498      * enough for the user to create an unimplemented_device as downstream
499      * if they have nothing else to plug into this.
500      */
501     if (!s->downstream) {
502         error_setg(errp, "MPC 'downstream' link not set");
503         return;
504     }
505 
506     size = memory_region_size(s->downstream);
507 
508     memory_region_init_iommu(&s->upstream, sizeof(s->upstream),
509                              TYPE_TZ_MPC_IOMMU_MEMORY_REGION,
510                              obj, "tz-mpc-upstream", size);
511 
512     /* In real hardware the block size is configurable. In QEMU we could
513      * make it configurable but will need it to be at least as big as the
514      * target page size so we can execute out of the resulting MRs. Guest
515      * software is supposed to check the block size using the BLK_CFG
516      * register, so make it fixed at the page size.
517      */
518     s->blocksize = memory_region_iommu_get_min_page_size(&s->upstream);
519     if (size % s->blocksize != 0) {
520         error_setg(errp,
521                    "MPC 'downstream' size %" PRId64
522                    " is not a multiple of %" HWADDR_PRIx " bytes",
523                    size, s->blocksize);
524         object_unref(OBJECT(&s->upstream));
525         return;
526     }
527 
528     /* BLK_MAX is the max value of BLK_IDX, which indexes an array of 32-bit
529      * words, each bit of which indicates one block.
530      */
531     s->blk_max = DIV_ROUND_UP(size / s->blocksize, 32);
532 
533     memory_region_init_io(&s->regmr, obj, &tz_mpc_reg_ops,
534                           s, "tz-mpc-regs", 0x1000);
535     sysbus_init_mmio(sbd, &s->regmr);
536 
537     sysbus_init_mmio(sbd, MEMORY_REGION(&s->upstream));
538 
539     /* This memory region is not exposed to users of this device as a
540      * sysbus MMIO region, but is instead used internally as something
541      * that our IOMMU translate function might direct accesses to.
542      */
543     memory_region_init_io(&s->blocked_io, obj, &tz_mpc_mem_blocked_ops,
544                           s, "tz-mpc-blocked-io", size);
545 
546     address_space_init(&s->downstream_as, s->downstream,
547                        "tz-mpc-downstream");
548     address_space_init(&s->blocked_io_as, &s->blocked_io,
549                        "tz-mpc-blocked-io");
550 
551     s->blk_lut = g_new0(uint32_t, s->blk_max);
552 }
553 
554 static int tz_mpc_post_load(void *opaque, int version_id)
555 {
556     TZMPC *s = TZ_MPC(opaque);
557 
558     /* Check the incoming data doesn't point blk_idx off the end of blk_lut. */
559     if (s->blk_idx >= s->blk_max) {
560         return -1;
561     }
562     return 0;
563 }
564 
565 static const VMStateDescription tz_mpc_vmstate = {
566     .name = "tz-mpc",
567     .version_id = 1,
568     .minimum_version_id = 1,
569     .post_load = tz_mpc_post_load,
570     .fields = (VMStateField[]) {
571         VMSTATE_UINT32(ctrl, TZMPC),
572         VMSTATE_UINT32(blk_idx, TZMPC),
573         VMSTATE_UINT32(int_stat, TZMPC),
574         VMSTATE_UINT32(int_en, TZMPC),
575         VMSTATE_UINT32(int_info1, TZMPC),
576         VMSTATE_UINT32(int_info2, TZMPC),
577         VMSTATE_VARRAY_UINT32(blk_lut, TZMPC, blk_max,
578                               0, vmstate_info_uint32, uint32_t),
579         VMSTATE_END_OF_LIST()
580     }
581 };
582 
583 static Property tz_mpc_properties[] = {
584     DEFINE_PROP_LINK("downstream", TZMPC, downstream,
585                      TYPE_MEMORY_REGION, MemoryRegion *),
586     DEFINE_PROP_END_OF_LIST(),
587 };
588 
589 static void tz_mpc_class_init(ObjectClass *klass, void *data)
590 {
591     DeviceClass *dc = DEVICE_CLASS(klass);
592 
593     dc->realize = tz_mpc_realize;
594     dc->vmsd = &tz_mpc_vmstate;
595     dc->reset = tz_mpc_reset;
596     dc->props = tz_mpc_properties;
597 }
598 
599 static const TypeInfo tz_mpc_info = {
600     .name = TYPE_TZ_MPC,
601     .parent = TYPE_SYS_BUS_DEVICE,
602     .instance_size = sizeof(TZMPC),
603     .instance_init = tz_mpc_init,
604     .class_init = tz_mpc_class_init,
605 };
606 
607 static void tz_mpc_iommu_memory_region_class_init(ObjectClass *klass,
608                                                   void *data)
609 {
610     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_CLASS(klass);
611 
612     imrc->translate = tz_mpc_translate;
613     imrc->attrs_to_index = tz_mpc_attrs_to_index;
614     imrc->num_indexes = tz_mpc_num_indexes;
615 }
616 
617 static const TypeInfo tz_mpc_iommu_memory_region_info = {
618     .name = TYPE_TZ_MPC_IOMMU_MEMORY_REGION,
619     .parent = TYPE_IOMMU_MEMORY_REGION,
620     .class_init = tz_mpc_iommu_memory_region_class_init,
621 };
622 
623 static void tz_mpc_register_types(void)
624 {
625     type_register_static(&tz_mpc_info);
626     type_register_static(&tz_mpc_iommu_memory_region_info);
627 }
628 
629 type_init(tz_mpc_register_types);
630