xref: /openbmc/qemu/hw/intc/arm_gicv3_dist.c (revision 99d423e5)
1 /*
2  * ARM GICv3 emulation: Distributor
3  *
4  * Copyright (c) 2015 Huawei.
5  * Copyright (c) 2016 Linaro Limited.
6  * Written by Shlomo Pongratz, Peter Maydell
7  *
8  * This code is licensed under the GPL, version 2 or (at your option)
9  * any later version.
10  */
11 
12 #include "qemu/osdep.h"
13 #include "qemu/log.h"
14 #include "trace.h"
15 #include "gicv3_internal.h"
16 
17 /* The GICD_NSACR registers contain a two bit field for each interrupt which
18  * allows the guest to give NonSecure code access to registers controlling
19  * Secure interrupts:
20  *  0b00: no access (NS accesses to bits for Secure interrupts will RAZ/WI)
21  *  0b01: NS r/w accesses permitted to ISPENDR, SETSPI_NSR, SGIR
22  *  0b10: as 0b01, and also r/w to ICPENDR, r/o to ISACTIVER/ICACTIVER,
23  *        and w/o to CLRSPI_NSR
24  *  0b11: as 0b10, and also r/w to IROUTER and ITARGETSR
25  *
26  * Given a (multiple-of-32) interrupt number, these mask functions return
27  * a mask word where each bit is 1 if the NSACR settings permit access
28  * to the interrupt. The mask returned can then be ORed with the GICD_GROUP
29  * word for this set of interrupts to give an overall mask.
30  */
31 
32 typedef uint32_t maskfn(GICv3State *s, int irq);
33 
34 static uint32_t mask_nsacr_ge1(GICv3State *s, int irq)
35 {
36     /* Return a mask where each bit is set if the NSACR field is >= 1 */
37     uint64_t raw_nsacr = s->gicd_nsacr[irq / 16 + 1];
38 
39     raw_nsacr = raw_nsacr << 32 | s->gicd_nsacr[irq / 16];
40     raw_nsacr = (raw_nsacr >> 1) | raw_nsacr;
41     return half_unshuffle64(raw_nsacr);
42 }
43 
44 static uint32_t mask_nsacr_ge2(GICv3State *s, int irq)
45 {
46     /* Return a mask where each bit is set if the NSACR field is >= 2 */
47     uint64_t raw_nsacr = s->gicd_nsacr[irq / 16 + 1];
48 
49     raw_nsacr = raw_nsacr << 32 | s->gicd_nsacr[irq / 16];
50     raw_nsacr = raw_nsacr >> 1;
51     return half_unshuffle64(raw_nsacr);
52 }
53 
54 /* We don't need a mask_nsacr_ge3() because IROUTER<n> isn't a bitmap register,
55  * but it would be implemented using:
56  *  raw_nsacr = (raw_nsacr >> 1) & raw_nsacr;
57  */
58 
59 static uint32_t mask_group_and_nsacr(GICv3State *s, MemTxAttrs attrs,
60                                      maskfn *maskfn, int irq)
61 {
62     /* Return a 32-bit mask which should be applied for this set of 32
63      * interrupts; each bit is 1 if access is permitted by the
64      * combination of attrs.secure, GICD_GROUPR and GICD_NSACR.
65      */
66     uint32_t mask;
67 
68     if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
69         /* bits for Group 0 or Secure Group 1 interrupts are RAZ/WI
70          * unless the NSACR bits permit access.
71          */
72         mask = *gic_bmp_ptr32(s->group, irq);
73         if (maskfn) {
74             mask |= maskfn(s, irq);
75         }
76         return mask;
77     }
78     return 0xFFFFFFFFU;
79 }
80 
81 static int gicd_ns_access(GICv3State *s, int irq)
82 {
83     /* Return the 2 bit NS_access<x> field from GICD_NSACR<n> for the
84      * specified interrupt.
85      */
86     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
87         return 0;
88     }
89     return extract32(s->gicd_nsacr[irq / 16], (irq % 16) * 2, 2);
90 }
91 
92 static void gicd_write_set_bitmap_reg(GICv3State *s, MemTxAttrs attrs,
93                                       uint32_t *bmp,
94                                       maskfn *maskfn,
95                                       int offset, uint32_t val)
96 {
97     /* Helper routine to implement writing to a "set-bitmap" register
98      * (GICD_ISENABLER, GICD_ISPENDR, etc).
99      * Semantics implemented here:
100      * RAZ/WI for SGIs, PPIs, unimplemented IRQs
101      * Bits corresponding to Group 0 or Secure Group 1 interrupts RAZ/WI.
102      * Writing 1 means "set bit in bitmap"; writing 0 is ignored.
103      * offset should be the offset in bytes of the register from the start
104      * of its group.
105      */
106     int irq = offset * 8;
107 
108     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
109         return;
110     }
111     val &= mask_group_and_nsacr(s, attrs, maskfn, irq);
112     *gic_bmp_ptr32(bmp, irq) |= val;
113     gicv3_update(s, irq, 32);
114 }
115 
116 static void gicd_write_clear_bitmap_reg(GICv3State *s, MemTxAttrs attrs,
117                                         uint32_t *bmp,
118                                         maskfn *maskfn,
119                                         int offset, uint32_t val)
120 {
121     /* Helper routine to implement writing to a "clear-bitmap" register
122      * (GICD_ICENABLER, GICD_ICPENDR, etc).
123      * Semantics implemented here:
124      * RAZ/WI for SGIs, PPIs, unimplemented IRQs
125      * Bits corresponding to Group 0 or Secure Group 1 interrupts RAZ/WI.
126      * Writing 1 means "clear bit in bitmap"; writing 0 is ignored.
127      * offset should be the offset in bytes of the register from the start
128      * of its group.
129      */
130     int irq = offset * 8;
131 
132     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
133         return;
134     }
135     val &= mask_group_and_nsacr(s, attrs, maskfn, irq);
136     *gic_bmp_ptr32(bmp, irq) &= ~val;
137     gicv3_update(s, irq, 32);
138 }
139 
140 static uint32_t gicd_read_bitmap_reg(GICv3State *s, MemTxAttrs attrs,
141                                      uint32_t *bmp,
142                                      maskfn *maskfn,
143                                      int offset)
144 {
145     /* Helper routine to implement reading a "set/clear-bitmap" register
146      * (GICD_ICENABLER, GICD_ISENABLER, GICD_ICPENDR, etc).
147      * Semantics implemented here:
148      * RAZ/WI for SGIs, PPIs, unimplemented IRQs
149      * Bits corresponding to Group 0 or Secure Group 1 interrupts RAZ/WI.
150      * offset should be the offset in bytes of the register from the start
151      * of its group.
152      */
153     int irq = offset * 8;
154     uint32_t val;
155 
156     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
157         return 0;
158     }
159     val = *gic_bmp_ptr32(bmp, irq);
160     if (bmp == s->pending) {
161         /* The PENDING register is a special case -- for level triggered
162          * interrupts, the PENDING state is the logical OR of the state of
163          * the PENDING latch with the input line level.
164          */
165         uint32_t edge = *gic_bmp_ptr32(s->edge_trigger, irq);
166         uint32_t level = *gic_bmp_ptr32(s->level, irq);
167         val |= (~edge & level);
168     }
169     val &= mask_group_and_nsacr(s, attrs, maskfn, irq);
170     return val;
171 }
172 
173 static uint8_t gicd_read_ipriorityr(GICv3State *s, MemTxAttrs attrs, int irq)
174 {
175     /* Read the value of GICD_IPRIORITYR<n> for the specified interrupt,
176      * honouring security state (these are RAZ/WI for Group 0 or Secure
177      * Group 1 interrupts).
178      */
179     uint32_t prio;
180 
181     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
182         return 0;
183     }
184 
185     prio = s->gicd_ipriority[irq];
186 
187     if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
188         if (!gicv3_gicd_group_test(s, irq)) {
189             /* Fields for Group 0 or Secure Group 1 interrupts are RAZ/WI */
190             return 0;
191         }
192         /* NS view of the interrupt priority */
193         prio = (prio << 1) & 0xff;
194     }
195     return prio;
196 }
197 
198 static void gicd_write_ipriorityr(GICv3State *s, MemTxAttrs attrs, int irq,
199                                   uint8_t value)
200 {
201     /* Write the value of GICD_IPRIORITYR<n> for the specified interrupt,
202      * honouring security state (these are RAZ/WI for Group 0 or Secure
203      * Group 1 interrupts).
204      */
205     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
206         return;
207     }
208 
209     if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
210         if (!gicv3_gicd_group_test(s, irq)) {
211             /* Fields for Group 0 or Secure Group 1 interrupts are RAZ/WI */
212             return;
213         }
214         /* NS view of the interrupt priority */
215         value = 0x80 | (value >> 1);
216     }
217     s->gicd_ipriority[irq] = value;
218 }
219 
220 static uint64_t gicd_read_irouter(GICv3State *s, MemTxAttrs attrs, int irq)
221 {
222     /* Read the value of GICD_IROUTER<n> for the specified interrupt,
223      * honouring security state.
224      */
225     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
226         return 0;
227     }
228 
229     if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
230         /* RAZ/WI for NS accesses to secure interrupts */
231         if (!gicv3_gicd_group_test(s, irq)) {
232             if (gicd_ns_access(s, irq) != 3) {
233                 return 0;
234             }
235         }
236     }
237 
238     return s->gicd_irouter[irq];
239 }
240 
241 static void gicd_write_irouter(GICv3State *s, MemTxAttrs attrs, int irq,
242                                uint64_t val)
243 {
244     /* Write the value of GICD_IROUTER<n> for the specified interrupt,
245      * honouring security state.
246      */
247     if (irq < GIC_INTERNAL || irq >= s->num_irq) {
248         return;
249     }
250 
251     if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
252         /* RAZ/WI for NS accesses to secure interrupts */
253         if (!gicv3_gicd_group_test(s, irq)) {
254             if (gicd_ns_access(s, irq) != 3) {
255                 return;
256             }
257         }
258     }
259 
260     s->gicd_irouter[irq] = val;
261     gicv3_cache_target_cpustate(s, irq);
262     gicv3_update(s, irq, 1);
263 }
264 
265 static MemTxResult gicd_readb(GICv3State *s, hwaddr offset,
266                               uint64_t *data, MemTxAttrs attrs)
267 {
268     /* Most GICv3 distributor registers do not support byte accesses. */
269     switch (offset) {
270     case GICD_CPENDSGIR ... GICD_CPENDSGIR + 0xf:
271     case GICD_SPENDSGIR ... GICD_SPENDSGIR + 0xf:
272     case GICD_ITARGETSR ... GICD_ITARGETSR + 0x3ff:
273         /* This GIC implementation always has affinity routing enabled,
274          * so these registers are all RAZ/WI.
275          */
276         return MEMTX_OK;
277     case GICD_IPRIORITYR ... GICD_IPRIORITYR + 0x3ff:
278         *data = gicd_read_ipriorityr(s, attrs, offset - GICD_IPRIORITYR);
279         return MEMTX_OK;
280     default:
281         return MEMTX_ERROR;
282     }
283 }
284 
285 static MemTxResult gicd_writeb(GICv3State *s, hwaddr offset,
286                                uint64_t value, MemTxAttrs attrs)
287 {
288     /* Most GICv3 distributor registers do not support byte accesses. */
289     switch (offset) {
290     case GICD_CPENDSGIR ... GICD_CPENDSGIR + 0xf:
291     case GICD_SPENDSGIR ... GICD_SPENDSGIR + 0xf:
292     case GICD_ITARGETSR ... GICD_ITARGETSR + 0x3ff:
293         /* This GIC implementation always has affinity routing enabled,
294          * so these registers are all RAZ/WI.
295          */
296         return MEMTX_OK;
297     case GICD_IPRIORITYR ... GICD_IPRIORITYR + 0x3ff:
298     {
299         int irq = offset - GICD_IPRIORITYR;
300 
301         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
302             return MEMTX_OK;
303         }
304         gicd_write_ipriorityr(s, attrs, irq, value);
305         gicv3_update(s, irq, 1);
306         return MEMTX_OK;
307     }
308     default:
309         return MEMTX_ERROR;
310     }
311 }
312 
313 static MemTxResult gicd_readw(GICv3State *s, hwaddr offset,
314                               uint64_t *data, MemTxAttrs attrs)
315 {
316     /* Only GICD_SETSPI_NSR, GICD_CLRSPI_NSR, GICD_SETSPI_SR and GICD_SETSPI_NSR
317      * support 16 bit accesses, and those registers are all part of the
318      * optional message-based SPI feature which this GIC does not currently
319      * implement (ie for us GICD_TYPER.MBIS == 0), so for us they are
320      * reserved.
321      */
322     return MEMTX_ERROR;
323 }
324 
325 static MemTxResult gicd_writew(GICv3State *s, hwaddr offset,
326                                uint64_t value, MemTxAttrs attrs)
327 {
328     /* Only GICD_SETSPI_NSR, GICD_CLRSPI_NSR, GICD_SETSPI_SR and GICD_SETSPI_NSR
329      * support 16 bit accesses, and those registers are all part of the
330      * optional message-based SPI feature which this GIC does not currently
331      * implement (ie for us GICD_TYPER.MBIS == 0), so for us they are
332      * reserved.
333      */
334     return MEMTX_ERROR;
335 }
336 
337 static MemTxResult gicd_readl(GICv3State *s, hwaddr offset,
338                               uint64_t *data, MemTxAttrs attrs)
339 {
340     /* Almost all GICv3 distributor registers are 32-bit.
341      * Note that WO registers must return an UNKNOWN value on reads,
342      * not an abort.
343      */
344 
345     switch (offset) {
346     case GICD_CTLR:
347         if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
348             /* The NS view of the GICD_CTLR sees only certain bits:
349              * + bit [31] (RWP) is an alias of the Secure bit [31]
350              * + bit [4] (ARE_NS) is an alias of Secure bit [5]
351              * + bit [1] (EnableGrp1A) is an alias of Secure bit [1] if
352              *   NS affinity routing is enabled, otherwise RES0
353              * + bit [0] (EnableGrp1) is an alias of Secure bit [1] if
354              *   NS affinity routing is not enabled, otherwise RES0
355              * Since for QEMU affinity routing is always enabled
356              * for both S and NS this means that bits [4] and [5] are
357              * both always 1, and we can simply make the NS view
358              * be bits 31, 4 and 1 of the S view.
359              */
360             *data = s->gicd_ctlr & (GICD_CTLR_ARE_S |
361                                     GICD_CTLR_EN_GRP1NS |
362                                     GICD_CTLR_RWP);
363         } else {
364             *data = s->gicd_ctlr;
365         }
366         return MEMTX_OK;
367     case GICD_TYPER:
368     {
369         /* For this implementation:
370          * No1N == 1 (1-of-N SPI interrupts not supported)
371          * A3V == 1 (non-zero values of Affinity level 3 supported)
372          * IDbits == 0xf (we support 16-bit interrupt identifiers)
373          * DVIS == 0 (Direct virtual LPI injection not supported)
374          * LPIS == 0 (LPIs not supported)
375          * MBIS == 0 (message-based SPIs not supported)
376          * SecurityExtn == 1 if security extns supported
377          * CPUNumber == 0 since for us ARE is always 1
378          * ITLinesNumber == (num external irqs / 32) - 1
379          */
380         int itlinesnumber = ((s->num_irq - GIC_INTERNAL) / 32) - 1;
381 
382         *data = (1 << 25) | (1 << 24) | (s->security_extn << 10) |
383             (0xf << 19) | itlinesnumber;
384         return MEMTX_OK;
385     }
386     case GICD_IIDR:
387         /* We claim to be an ARM r0p0 with a zero ProductID.
388          * This is the same as an r0p0 GIC-500.
389          */
390         *data = gicv3_iidr();
391         return MEMTX_OK;
392     case GICD_STATUSR:
393         /* RAZ/WI for us (this is an optional register and our implementation
394          * does not track RO/WO/reserved violations to report them to the guest)
395          */
396         *data = 0;
397         return MEMTX_OK;
398     case GICD_IGROUPR ... GICD_IGROUPR + 0x7f:
399     {
400         int irq;
401 
402         if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
403             *data = 0;
404             return MEMTX_OK;
405         }
406         /* RAZ/WI for SGIs, PPIs, unimplemented irqs */
407         irq = (offset - GICD_IGROUPR) * 8;
408         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
409             *data = 0;
410             return MEMTX_OK;
411         }
412         *data = *gic_bmp_ptr32(s->group, irq);
413         return MEMTX_OK;
414     }
415     case GICD_ISENABLER ... GICD_ISENABLER + 0x7f:
416         *data = gicd_read_bitmap_reg(s, attrs, s->enabled, NULL,
417                                      offset - GICD_ISENABLER);
418         return MEMTX_OK;
419     case GICD_ICENABLER ... GICD_ICENABLER + 0x7f:
420         *data = gicd_read_bitmap_reg(s, attrs, s->enabled, NULL,
421                                      offset - GICD_ICENABLER);
422         return MEMTX_OK;
423     case GICD_ISPENDR ... GICD_ISPENDR + 0x7f:
424         *data = gicd_read_bitmap_reg(s, attrs, s->pending, mask_nsacr_ge1,
425                                      offset - GICD_ISPENDR);
426         return MEMTX_OK;
427     case GICD_ICPENDR ... GICD_ICPENDR + 0x7f:
428         *data = gicd_read_bitmap_reg(s, attrs, s->pending, mask_nsacr_ge2,
429                                      offset - GICD_ICPENDR);
430         return MEMTX_OK;
431     case GICD_ISACTIVER ... GICD_ISACTIVER + 0x7f:
432         *data = gicd_read_bitmap_reg(s, attrs, s->active, mask_nsacr_ge2,
433                                      offset - GICD_ISACTIVER);
434         return MEMTX_OK;
435     case GICD_ICACTIVER ... GICD_ICACTIVER + 0x7f:
436         *data = gicd_read_bitmap_reg(s, attrs, s->active, mask_nsacr_ge2,
437                                      offset - GICD_ICACTIVER);
438         return MEMTX_OK;
439     case GICD_IPRIORITYR ... GICD_IPRIORITYR + 0x3ff:
440     {
441         int i, irq = offset - GICD_IPRIORITYR;
442         uint32_t value = 0;
443 
444         for (i = irq + 3; i >= irq; i--) {
445             value <<= 8;
446             value |= gicd_read_ipriorityr(s, attrs, i);
447         }
448         *data = value;
449         return MEMTX_OK;
450     }
451     case GICD_ITARGETSR ... GICD_ITARGETSR + 0x3ff:
452         /* RAZ/WI since affinity routing is always enabled */
453         *data = 0;
454         return MEMTX_OK;
455     case GICD_ICFGR ... GICD_ICFGR + 0xff:
456     {
457         /* Here only the even bits are used; odd bits are RES0 */
458         int irq = (offset - GICD_ICFGR) * 4;
459         uint32_t value = 0;
460 
461         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
462             *data = 0;
463             return MEMTX_OK;
464         }
465 
466         /* Since our edge_trigger bitmap is one bit per irq, we only need
467          * half of the 32-bit word, which we can then spread out
468          * into the odd bits.
469          */
470         value = *gic_bmp_ptr32(s->edge_trigger, irq & ~0x1f);
471         value &= mask_group_and_nsacr(s, attrs, NULL, irq & ~0x1f);
472         value = extract32(value, (irq & 0x1f) ? 16 : 0, 16);
473         value = half_shuffle32(value) << 1;
474         *data = value;
475         return MEMTX_OK;
476     }
477     case GICD_IGRPMODR ... GICD_IGRPMODR + 0xff:
478     {
479         int irq;
480 
481         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
482             /* RAZ/WI if security disabled, or if
483              * security enabled and this is an NS access
484              */
485             *data = 0;
486             return MEMTX_OK;
487         }
488         /* RAZ/WI for SGIs, PPIs, unimplemented irqs */
489         irq = (offset - GICD_IGRPMODR) * 8;
490         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
491             *data = 0;
492             return MEMTX_OK;
493         }
494         *data = *gic_bmp_ptr32(s->grpmod, irq);
495         return MEMTX_OK;
496     }
497     case GICD_NSACR ... GICD_NSACR + 0xff:
498     {
499         /* Two bits per interrupt */
500         int irq = (offset - GICD_NSACR) * 4;
501 
502         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
503             *data = 0;
504             return MEMTX_OK;
505         }
506 
507         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
508             /* RAZ/WI if security disabled, or if
509              * security enabled and this is an NS access
510              */
511             *data = 0;
512             return MEMTX_OK;
513         }
514 
515         *data = s->gicd_nsacr[irq / 16];
516         return MEMTX_OK;
517     }
518     case GICD_CPENDSGIR ... GICD_CPENDSGIR + 0xf:
519     case GICD_SPENDSGIR ... GICD_SPENDSGIR + 0xf:
520         /* RAZ/WI since affinity routing is always enabled */
521         *data = 0;
522         return MEMTX_OK;
523     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
524     {
525         uint64_t r;
526         int irq = (offset - GICD_IROUTER) / 8;
527 
528         r = gicd_read_irouter(s, attrs, irq);
529         if (offset & 7) {
530             *data = r >> 32;
531         } else {
532             *data = (uint32_t)r;
533         }
534         return MEMTX_OK;
535     }
536     case GICD_IDREGS ... GICD_IDREGS + 0x1f:
537         /* ID registers */
538         *data = gicv3_idreg(offset - GICD_IDREGS);
539         return MEMTX_OK;
540     case GICD_SGIR:
541         /* WO registers, return unknown value */
542         qemu_log_mask(LOG_GUEST_ERROR,
543                       "%s: invalid guest read from WO register at offset "
544                       TARGET_FMT_plx "\n", __func__, offset);
545         *data = 0;
546         return MEMTX_OK;
547     default:
548         return MEMTX_ERROR;
549     }
550 }
551 
552 static MemTxResult gicd_writel(GICv3State *s, hwaddr offset,
553                                uint64_t value, MemTxAttrs attrs)
554 {
555     /* Almost all GICv3 distributor registers are 32-bit. Note that
556      * RO registers must ignore writes, not abort.
557      */
558 
559     switch (offset) {
560     case GICD_CTLR:
561     {
562         uint32_t mask;
563         /* GICv3 5.3.20 */
564         if (s->gicd_ctlr & GICD_CTLR_DS) {
565             /* With only one security state, E1NWF is RAZ/WI, DS is RAO/WI,
566              * ARE is RAO/WI (affinity routing always on), and only
567              * bits 0 and 1 (group enables) are writable.
568              */
569             mask = GICD_CTLR_EN_GRP0 | GICD_CTLR_EN_GRP1NS;
570         } else {
571             if (attrs.secure) {
572                 /* for secure access:
573                  * ARE_NS and ARE_S are RAO/WI (affinity routing always on)
574                  * E1NWF is RAZ/WI (we don't support enable-1-of-n-wakeup)
575                  *
576                  * We can only modify bits[2:0] (the group enables).
577                  */
578                 mask = GICD_CTLR_DS | GICD_CTLR_EN_GRP0 | GICD_CTLR_EN_GRP1_ALL;
579             } else {
580                 /* For non secure access ARE_NS is RAO/WI and EnableGrp1
581                  * is RES0. The only writable bit is [1] (EnableGrp1A), which
582                  * is an alias of the Secure bit [1].
583                  */
584                 mask = GICD_CTLR_EN_GRP1NS;
585             }
586         }
587         s->gicd_ctlr = (s->gicd_ctlr & ~mask) | (value & mask);
588         if (value & mask & GICD_CTLR_DS) {
589             /* We just set DS, so the ARE_NS and EnG1S bits are now RES0.
590              * Note that this is a one-way transition because if DS is set
591              * then it's not writeable, so it can only go back to 0 with a
592              * hardware reset.
593              */
594             s->gicd_ctlr &= ~(GICD_CTLR_EN_GRP1S | GICD_CTLR_ARE_NS);
595         }
596         gicv3_full_update(s);
597         return MEMTX_OK;
598     }
599     case GICD_STATUSR:
600         /* RAZ/WI for our implementation */
601         return MEMTX_OK;
602     case GICD_IGROUPR ... GICD_IGROUPR + 0x7f:
603     {
604         int irq;
605 
606         if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
607             return MEMTX_OK;
608         }
609         /* RAZ/WI for SGIs, PPIs, unimplemented irqs */
610         irq = (offset - GICD_IGROUPR) * 8;
611         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
612             return MEMTX_OK;
613         }
614         *gic_bmp_ptr32(s->group, irq) = value;
615         gicv3_update(s, irq, 32);
616         return MEMTX_OK;
617     }
618     case GICD_ISENABLER ... GICD_ISENABLER + 0x7f:
619         gicd_write_set_bitmap_reg(s, attrs, s->enabled, NULL,
620                                   offset - GICD_ISENABLER, value);
621         return MEMTX_OK;
622     case GICD_ICENABLER ... GICD_ICENABLER + 0x7f:
623         gicd_write_clear_bitmap_reg(s, attrs, s->enabled, NULL,
624                                     offset - GICD_ICENABLER, value);
625         return MEMTX_OK;
626     case GICD_ISPENDR ... GICD_ISPENDR + 0x7f:
627         gicd_write_set_bitmap_reg(s, attrs, s->pending, mask_nsacr_ge1,
628                                   offset - GICD_ISPENDR, value);
629         return MEMTX_OK;
630     case GICD_ICPENDR ... GICD_ICPENDR + 0x7f:
631         gicd_write_clear_bitmap_reg(s, attrs, s->pending, mask_nsacr_ge2,
632                                     offset - GICD_ICPENDR, value);
633         return MEMTX_OK;
634     case GICD_ISACTIVER ... GICD_ISACTIVER + 0x7f:
635         gicd_write_set_bitmap_reg(s, attrs, s->active, NULL,
636                                   offset - GICD_ISACTIVER, value);
637         return MEMTX_OK;
638     case GICD_ICACTIVER ... GICD_ICACTIVER + 0x7f:
639         gicd_write_clear_bitmap_reg(s, attrs, s->active, NULL,
640                                     offset - GICD_ICACTIVER, value);
641         return MEMTX_OK;
642     case GICD_IPRIORITYR ... GICD_IPRIORITYR + 0x3ff:
643     {
644         int i, irq = offset - GICD_IPRIORITYR;
645 
646         if (irq < GIC_INTERNAL || irq + 3 >= s->num_irq) {
647             return MEMTX_OK;
648         }
649 
650         for (i = irq; i < irq + 4; i++, value >>= 8) {
651             gicd_write_ipriorityr(s, attrs, i, value);
652         }
653         gicv3_update(s, irq, 4);
654         return MEMTX_OK;
655     }
656     case GICD_ITARGETSR ... GICD_ITARGETSR + 0x3ff:
657         /* RAZ/WI since affinity routing is always enabled */
658         return MEMTX_OK;
659     case GICD_ICFGR ... GICD_ICFGR + 0xff:
660     {
661         /* Here only the odd bits are used; even bits are RES0 */
662         int irq = (offset - GICD_ICFGR) * 4;
663         uint32_t mask, oldval;
664 
665         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
666             return MEMTX_OK;
667         }
668 
669         /* Since our edge_trigger bitmap is one bit per irq, our input
670          * 32-bits will compress down into 16 bits which we need
671          * to write into the bitmap.
672          */
673         value = half_unshuffle32(value >> 1);
674         mask = mask_group_and_nsacr(s, attrs, NULL, irq & ~0x1f);
675         if (irq & 0x1f) {
676             value <<= 16;
677             mask &= 0xffff0000U;
678         } else {
679             mask &= 0xffff;
680         }
681         oldval = *gic_bmp_ptr32(s->edge_trigger, (irq & ~0x1f));
682         value = (oldval & ~mask) | (value & mask);
683         *gic_bmp_ptr32(s->edge_trigger, irq & ~0x1f) = value;
684         return MEMTX_OK;
685     }
686     case GICD_IGRPMODR ... GICD_IGRPMODR + 0xff:
687     {
688         int irq;
689 
690         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
691             /* RAZ/WI if security disabled, or if
692              * security enabled and this is an NS access
693              */
694             return MEMTX_OK;
695         }
696         /* RAZ/WI for SGIs, PPIs, unimplemented irqs */
697         irq = (offset - GICD_IGRPMODR) * 8;
698         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
699             return MEMTX_OK;
700         }
701         *gic_bmp_ptr32(s->grpmod, irq) = value;
702         gicv3_update(s, irq, 32);
703         return MEMTX_OK;
704     }
705     case GICD_NSACR ... GICD_NSACR + 0xff:
706     {
707         /* Two bits per interrupt */
708         int irq = (offset - GICD_NSACR) * 4;
709 
710         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
711             return MEMTX_OK;
712         }
713 
714         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
715             /* RAZ/WI if security disabled, or if
716              * security enabled and this is an NS access
717              */
718             return MEMTX_OK;
719         }
720 
721         s->gicd_nsacr[irq / 16] = value;
722         /* No update required as this only affects access permission checks */
723         return MEMTX_OK;
724     }
725     case GICD_SGIR:
726         /* RES0 if affinity routing is enabled */
727         return MEMTX_OK;
728     case GICD_CPENDSGIR ... GICD_CPENDSGIR + 0xf:
729     case GICD_SPENDSGIR ... GICD_SPENDSGIR + 0xf:
730         /* RAZ/WI since affinity routing is always enabled */
731         return MEMTX_OK;
732     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
733     {
734         uint64_t r;
735         int irq = (offset - GICD_IROUTER) / 8;
736 
737         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
738             return MEMTX_OK;
739         }
740 
741         /* Write half of the 64-bit register */
742         r = gicd_read_irouter(s, attrs, irq);
743         r = deposit64(r, (offset & 7) ? 32 : 0, 32, value);
744         gicd_write_irouter(s, attrs, irq, r);
745         return MEMTX_OK;
746     }
747     case GICD_IDREGS ... GICD_IDREGS + 0x1f:
748     case GICD_TYPER:
749     case GICD_IIDR:
750         /* RO registers, ignore the write */
751         qemu_log_mask(LOG_GUEST_ERROR,
752                       "%s: invalid guest write to RO register at offset "
753                       TARGET_FMT_plx "\n", __func__, offset);
754         return MEMTX_OK;
755     default:
756         return MEMTX_ERROR;
757     }
758 }
759 
760 static MemTxResult gicd_writell(GICv3State *s, hwaddr offset,
761                                 uint64_t value, MemTxAttrs attrs)
762 {
763     /* Our only 64-bit registers are GICD_IROUTER<n> */
764     int irq;
765 
766     switch (offset) {
767     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
768         irq = (offset - GICD_IROUTER) / 8;
769         gicd_write_irouter(s, attrs, irq, value);
770         return MEMTX_OK;
771     default:
772         return MEMTX_ERROR;
773     }
774 }
775 
776 static MemTxResult gicd_readll(GICv3State *s, hwaddr offset,
777                                uint64_t *data, MemTxAttrs attrs)
778 {
779     /* Our only 64-bit registers are GICD_IROUTER<n> */
780     int irq;
781 
782     switch (offset) {
783     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
784         irq = (offset - GICD_IROUTER) / 8;
785         *data = gicd_read_irouter(s, attrs, irq);
786         return MEMTX_OK;
787     default:
788         return MEMTX_ERROR;
789     }
790 }
791 
792 MemTxResult gicv3_dist_read(void *opaque, hwaddr offset, uint64_t *data,
793                             unsigned size, MemTxAttrs attrs)
794 {
795     GICv3State *s = (GICv3State *)opaque;
796     MemTxResult r;
797 
798     switch (size) {
799     case 1:
800         r = gicd_readb(s, offset, data, attrs);
801         break;
802     case 2:
803         r = gicd_readw(s, offset, data, attrs);
804         break;
805     case 4:
806         r = gicd_readl(s, offset, data, attrs);
807         break;
808     case 8:
809         r = gicd_readll(s, offset, data, attrs);
810         break;
811     default:
812         r = MEMTX_ERROR;
813         break;
814     }
815 
816     if (r == MEMTX_ERROR) {
817         qemu_log_mask(LOG_GUEST_ERROR,
818                       "%s: invalid guest read at offset " TARGET_FMT_plx
819                       "size %u\n", __func__, offset, size);
820         trace_gicv3_dist_badread(offset, size, attrs.secure);
821         /* The spec requires that reserved registers are RAZ/WI;
822          * so use MEMTX_ERROR returns from leaf functions as a way to
823          * trigger the guest-error logging but don't return it to
824          * the caller, or we'll cause a spurious guest data abort.
825          */
826         r = MEMTX_OK;
827         *data = 0;
828     } else {
829         trace_gicv3_dist_read(offset, *data, size, attrs.secure);
830     }
831     return r;
832 }
833 
834 MemTxResult gicv3_dist_write(void *opaque, hwaddr offset, uint64_t data,
835                              unsigned size, MemTxAttrs attrs)
836 {
837     GICv3State *s = (GICv3State *)opaque;
838     MemTxResult r;
839 
840     switch (size) {
841     case 1:
842         r = gicd_writeb(s, offset, data, attrs);
843         break;
844     case 2:
845         r = gicd_writew(s, offset, data, attrs);
846         break;
847     case 4:
848         r = gicd_writel(s, offset, data, attrs);
849         break;
850     case 8:
851         r = gicd_writell(s, offset, data, attrs);
852         break;
853     default:
854         r = MEMTX_ERROR;
855         break;
856     }
857 
858     if (r == MEMTX_ERROR) {
859         qemu_log_mask(LOG_GUEST_ERROR,
860                       "%s: invalid guest write at offset " TARGET_FMT_plx
861                       "size %u\n", __func__, offset, size);
862         trace_gicv3_dist_badwrite(offset, data, size, attrs.secure);
863         /* The spec requires that reserved registers are RAZ/WI;
864          * so use MEMTX_ERROR returns from leaf functions as a way to
865          * trigger the guest-error logging but don't return it to
866          * the caller, or we'll cause a spurious guest data abort.
867          */
868         r = MEMTX_OK;
869     } else {
870         trace_gicv3_dist_write(offset, data, size, attrs.secure);
871     }
872     return r;
873 }
874 
875 void gicv3_dist_set_irq(GICv3State *s, int irq, int level)
876 {
877     /* Update distributor state for a change in an external SPI input line */
878     if (level == gicv3_gicd_level_test(s, irq)) {
879         return;
880     }
881 
882     trace_gicv3_dist_set_irq(irq, level);
883 
884     gicv3_gicd_level_replace(s, irq, level);
885 
886     if (level) {
887         /* 0->1 edges latch the pending bit for edge-triggered interrupts */
888         if (gicv3_gicd_edge_trigger_test(s, irq)) {
889             gicv3_gicd_pending_set(s, irq);
890         }
891     }
892 
893     gicv3_update(s, irq, 1);
894 }
895