xref: /openbmc/qemu/hw/intc/arm_gicv3_dist.c (revision dc5bd18f)
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--, value <<= 8) {
445             value |= gicd_read_ipriorityr(s, attrs, i);
446         }
447         *data = value;
448         return MEMTX_OK;
449     }
450     case GICD_ITARGETSR ... GICD_ITARGETSR + 0x3ff:
451         /* RAZ/WI since affinity routing is always enabled */
452         *data = 0;
453         return MEMTX_OK;
454     case GICD_ICFGR ... GICD_ICFGR + 0xff:
455     {
456         /* Here only the even bits are used; odd bits are RES0 */
457         int irq = (offset - GICD_ICFGR) * 4;
458         uint32_t value = 0;
459 
460         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
461             *data = 0;
462             return MEMTX_OK;
463         }
464 
465         /* Since our edge_trigger bitmap is one bit per irq, we only need
466          * half of the 32-bit word, which we can then spread out
467          * into the odd bits.
468          */
469         value = *gic_bmp_ptr32(s->edge_trigger, irq & ~0x1f);
470         value &= mask_group_and_nsacr(s, attrs, NULL, irq & ~0x1f);
471         value = extract32(value, (irq & 0x1f) ? 16 : 0, 16);
472         value = half_shuffle32(value) << 1;
473         *data = value;
474         return MEMTX_OK;
475     }
476     case GICD_IGRPMODR ... GICD_IGRPMODR + 0xff:
477     {
478         int irq;
479 
480         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
481             /* RAZ/WI if security disabled, or if
482              * security enabled and this is an NS access
483              */
484             *data = 0;
485             return MEMTX_OK;
486         }
487         /* RAZ/WI for SGIs, PPIs, unimplemented irqs */
488         irq = (offset - GICD_IGRPMODR) * 8;
489         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
490             *data = 0;
491             return MEMTX_OK;
492         }
493         *data = *gic_bmp_ptr32(s->grpmod, irq);
494         return MEMTX_OK;
495     }
496     case GICD_NSACR ... GICD_NSACR + 0xff:
497     {
498         /* Two bits per interrupt */
499         int irq = (offset - GICD_NSACR) * 4;
500 
501         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
502             *data = 0;
503             return MEMTX_OK;
504         }
505 
506         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
507             /* RAZ/WI if security disabled, or if
508              * security enabled and this is an NS access
509              */
510             *data = 0;
511             return MEMTX_OK;
512         }
513 
514         *data = s->gicd_nsacr[irq / 16];
515         return MEMTX_OK;
516     }
517     case GICD_CPENDSGIR ... GICD_CPENDSGIR + 0xf:
518     case GICD_SPENDSGIR ... GICD_SPENDSGIR + 0xf:
519         /* RAZ/WI since affinity routing is always enabled */
520         *data = 0;
521         return MEMTX_OK;
522     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
523     {
524         uint64_t r;
525         int irq = (offset - GICD_IROUTER) / 8;
526 
527         r = gicd_read_irouter(s, attrs, irq);
528         if (offset & 7) {
529             *data = r >> 32;
530         } else {
531             *data = (uint32_t)r;
532         }
533         return MEMTX_OK;
534     }
535     case GICD_IDREGS ... GICD_IDREGS + 0x1f:
536         /* ID registers */
537         *data = gicv3_idreg(offset - GICD_IDREGS);
538         return MEMTX_OK;
539     case GICD_SGIR:
540         /* WO registers, return unknown value */
541         qemu_log_mask(LOG_GUEST_ERROR,
542                       "%s: invalid guest read from WO register at offset "
543                       TARGET_FMT_plx "\n", __func__, offset);
544         *data = 0;
545         return MEMTX_OK;
546     default:
547         return MEMTX_ERROR;
548     }
549 }
550 
551 static MemTxResult gicd_writel(GICv3State *s, hwaddr offset,
552                                uint64_t value, MemTxAttrs attrs)
553 {
554     /* Almost all GICv3 distributor registers are 32-bit. Note that
555      * RO registers must ignore writes, not abort.
556      */
557 
558     switch (offset) {
559     case GICD_CTLR:
560     {
561         uint32_t mask;
562         /* GICv3 5.3.20 */
563         if (s->gicd_ctlr & GICD_CTLR_DS) {
564             /* With only one security state, E1NWF is RAZ/WI, DS is RAO/WI,
565              * ARE is RAO/WI (affinity routing always on), and only
566              * bits 0 and 1 (group enables) are writable.
567              */
568             mask = GICD_CTLR_EN_GRP0 | GICD_CTLR_EN_GRP1NS;
569         } else {
570             if (attrs.secure) {
571                 /* for secure access:
572                  * ARE_NS and ARE_S are RAO/WI (affinity routing always on)
573                  * E1NWF is RAZ/WI (we don't support enable-1-of-n-wakeup)
574                  *
575                  * We can only modify bits[2:0] (the group enables).
576                  */
577                 mask = GICD_CTLR_DS | GICD_CTLR_EN_GRP0 | GICD_CTLR_EN_GRP1_ALL;
578             } else {
579                 /* For non secure access ARE_NS is RAO/WI and EnableGrp1
580                  * is RES0. The only writable bit is [1] (EnableGrp1A), which
581                  * is an alias of the Secure bit [1].
582                  */
583                 mask = GICD_CTLR_EN_GRP1NS;
584             }
585         }
586         s->gicd_ctlr = (s->gicd_ctlr & ~mask) | (value & mask);
587         if (value & mask & GICD_CTLR_DS) {
588             /* We just set DS, so the ARE_NS and EnG1S bits are now RES0.
589              * Note that this is a one-way transition because if DS is set
590              * then it's not writeable, so it can only go back to 0 with a
591              * hardware reset.
592              */
593             s->gicd_ctlr &= ~(GICD_CTLR_EN_GRP1S | GICD_CTLR_ARE_NS);
594         }
595         gicv3_full_update(s);
596         return MEMTX_OK;
597     }
598     case GICD_STATUSR:
599         /* RAZ/WI for our implementation */
600         return MEMTX_OK;
601     case GICD_IGROUPR ... GICD_IGROUPR + 0x7f:
602     {
603         int irq;
604 
605         if (!attrs.secure && !(s->gicd_ctlr & GICD_CTLR_DS)) {
606             return MEMTX_OK;
607         }
608         /* RAZ/WI for SGIs, PPIs, unimplemented irqs */
609         irq = (offset - GICD_IGROUPR) * 8;
610         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
611             return MEMTX_OK;
612         }
613         *gic_bmp_ptr32(s->group, irq) = value;
614         gicv3_update(s, irq, 32);
615         return MEMTX_OK;
616     }
617     case GICD_ISENABLER ... GICD_ISENABLER + 0x7f:
618         gicd_write_set_bitmap_reg(s, attrs, s->enabled, NULL,
619                                   offset - GICD_ISENABLER, value);
620         return MEMTX_OK;
621     case GICD_ICENABLER ... GICD_ICENABLER + 0x7f:
622         gicd_write_clear_bitmap_reg(s, attrs, s->enabled, NULL,
623                                     offset - GICD_ICENABLER, value);
624         return MEMTX_OK;
625     case GICD_ISPENDR ... GICD_ISPENDR + 0x7f:
626         gicd_write_set_bitmap_reg(s, attrs, s->pending, mask_nsacr_ge1,
627                                   offset - GICD_ISPENDR, value);
628         return MEMTX_OK;
629     case GICD_ICPENDR ... GICD_ICPENDR + 0x7f:
630         gicd_write_clear_bitmap_reg(s, attrs, s->pending, mask_nsacr_ge2,
631                                     offset - GICD_ICPENDR, value);
632         return MEMTX_OK;
633     case GICD_ISACTIVER ... GICD_ISACTIVER + 0x7f:
634         gicd_write_set_bitmap_reg(s, attrs, s->active, NULL,
635                                   offset - GICD_ISACTIVER, value);
636         return MEMTX_OK;
637     case GICD_ICACTIVER ... GICD_ICACTIVER + 0x7f:
638         gicd_write_clear_bitmap_reg(s, attrs, s->active, NULL,
639                                     offset - GICD_ICACTIVER, value);
640         return MEMTX_OK;
641     case GICD_IPRIORITYR ... GICD_IPRIORITYR + 0x3ff:
642     {
643         int i, irq = offset - GICD_IPRIORITYR;
644 
645         if (irq < GIC_INTERNAL || irq + 3 >= s->num_irq) {
646             return MEMTX_OK;
647         }
648 
649         for (i = irq; i < irq + 4; i++, value >>= 8) {
650             gicd_write_ipriorityr(s, attrs, i, value);
651         }
652         gicv3_update(s, irq, 4);
653         return MEMTX_OK;
654     }
655     case GICD_ITARGETSR ... GICD_ITARGETSR + 0x3ff:
656         /* RAZ/WI since affinity routing is always enabled */
657         return MEMTX_OK;
658     case GICD_ICFGR ... GICD_ICFGR + 0xff:
659     {
660         /* Here only the odd bits are used; even bits are RES0 */
661         int irq = (offset - GICD_ICFGR) * 4;
662         uint32_t mask, oldval;
663 
664         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
665             return MEMTX_OK;
666         }
667 
668         /* Since our edge_trigger bitmap is one bit per irq, our input
669          * 32-bits will compress down into 16 bits which we need
670          * to write into the bitmap.
671          */
672         value = half_unshuffle32(value >> 1);
673         mask = mask_group_and_nsacr(s, attrs, NULL, irq & ~0x1f);
674         if (irq & 0x1f) {
675             value <<= 16;
676             mask &= 0xffff0000U;
677         } else {
678             mask &= 0xffff;
679         }
680         oldval = *gic_bmp_ptr32(s->edge_trigger, (irq & ~0x1f));
681         value = (oldval & ~mask) | (value & mask);
682         *gic_bmp_ptr32(s->edge_trigger, irq & ~0x1f) = value;
683         return MEMTX_OK;
684     }
685     case GICD_IGRPMODR ... GICD_IGRPMODR + 0xff:
686     {
687         int irq;
688 
689         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
690             /* RAZ/WI if security disabled, or if
691              * security enabled and this is an NS access
692              */
693             return MEMTX_OK;
694         }
695         /* RAZ/WI for SGIs, PPIs, unimplemented irqs */
696         irq = (offset - GICD_IGRPMODR) * 8;
697         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
698             return MEMTX_OK;
699         }
700         *gic_bmp_ptr32(s->grpmod, irq) = value;
701         gicv3_update(s, irq, 32);
702         return MEMTX_OK;
703     }
704     case GICD_NSACR ... GICD_NSACR + 0xff:
705     {
706         /* Two bits per interrupt */
707         int irq = (offset - GICD_NSACR) * 4;
708 
709         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
710             return MEMTX_OK;
711         }
712 
713         if ((s->gicd_ctlr & GICD_CTLR_DS) || !attrs.secure) {
714             /* RAZ/WI if security disabled, or if
715              * security enabled and this is an NS access
716              */
717             return MEMTX_OK;
718         }
719 
720         s->gicd_nsacr[irq / 16] = value;
721         /* No update required as this only affects access permission checks */
722         return MEMTX_OK;
723     }
724     case GICD_SGIR:
725         /* RES0 if affinity routing is enabled */
726         return MEMTX_OK;
727     case GICD_CPENDSGIR ... GICD_CPENDSGIR + 0xf:
728     case GICD_SPENDSGIR ... GICD_SPENDSGIR + 0xf:
729         /* RAZ/WI since affinity routing is always enabled */
730         return MEMTX_OK;
731     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
732     {
733         uint64_t r;
734         int irq = (offset - GICD_IROUTER) / 8;
735 
736         if (irq < GIC_INTERNAL || irq >= s->num_irq) {
737             return MEMTX_OK;
738         }
739 
740         /* Write half of the 64-bit register */
741         r = gicd_read_irouter(s, attrs, irq);
742         r = deposit64(r, (offset & 7) ? 32 : 0, 32, value);
743         gicd_write_irouter(s, attrs, irq, r);
744         return MEMTX_OK;
745     }
746     case GICD_IDREGS ... GICD_IDREGS + 0x1f:
747     case GICD_TYPER:
748     case GICD_IIDR:
749         /* RO registers, ignore the write */
750         qemu_log_mask(LOG_GUEST_ERROR,
751                       "%s: invalid guest write to RO register at offset "
752                       TARGET_FMT_plx "\n", __func__, offset);
753         return MEMTX_OK;
754     default:
755         return MEMTX_ERROR;
756     }
757 }
758 
759 static MemTxResult gicd_writell(GICv3State *s, hwaddr offset,
760                                 uint64_t value, MemTxAttrs attrs)
761 {
762     /* Our only 64-bit registers are GICD_IROUTER<n> */
763     int irq;
764 
765     switch (offset) {
766     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
767         irq = (offset - GICD_IROUTER) / 8;
768         gicd_write_irouter(s, attrs, irq, value);
769         return MEMTX_OK;
770     default:
771         return MEMTX_ERROR;
772     }
773 }
774 
775 static MemTxResult gicd_readll(GICv3State *s, hwaddr offset,
776                                uint64_t *data, MemTxAttrs attrs)
777 {
778     /* Our only 64-bit registers are GICD_IROUTER<n> */
779     int irq;
780 
781     switch (offset) {
782     case GICD_IROUTER ... GICD_IROUTER + 0x1fdf:
783         irq = (offset - GICD_IROUTER) / 8;
784         *data = gicd_read_irouter(s, attrs, irq);
785         return MEMTX_OK;
786     default:
787         return MEMTX_ERROR;
788     }
789 }
790 
791 MemTxResult gicv3_dist_read(void *opaque, hwaddr offset, uint64_t *data,
792                             unsigned size, MemTxAttrs attrs)
793 {
794     GICv3State *s = (GICv3State *)opaque;
795     MemTxResult r;
796 
797     switch (size) {
798     case 1:
799         r = gicd_readb(s, offset, data, attrs);
800         break;
801     case 2:
802         r = gicd_readw(s, offset, data, attrs);
803         break;
804     case 4:
805         r = gicd_readl(s, offset, data, attrs);
806         break;
807     case 8:
808         r = gicd_readll(s, offset, data, attrs);
809         break;
810     default:
811         r = MEMTX_ERROR;
812         break;
813     }
814 
815     if (r == MEMTX_ERROR) {
816         qemu_log_mask(LOG_GUEST_ERROR,
817                       "%s: invalid guest read at offset " TARGET_FMT_plx
818                       "size %u\n", __func__, offset, size);
819         trace_gicv3_dist_badread(offset, size, attrs.secure);
820         /* The spec requires that reserved registers are RAZ/WI;
821          * so use MEMTX_ERROR returns from leaf functions as a way to
822          * trigger the guest-error logging but don't return it to
823          * the caller, or we'll cause a spurious guest data abort.
824          */
825         r = MEMTX_OK;
826         *data = 0;
827     } else {
828         trace_gicv3_dist_read(offset, *data, size, attrs.secure);
829     }
830     return r;
831 }
832 
833 MemTxResult gicv3_dist_write(void *opaque, hwaddr offset, uint64_t data,
834                              unsigned size, MemTxAttrs attrs)
835 {
836     GICv3State *s = (GICv3State *)opaque;
837     MemTxResult r;
838 
839     switch (size) {
840     case 1:
841         r = gicd_writeb(s, offset, data, attrs);
842         break;
843     case 2:
844         r = gicd_writew(s, offset, data, attrs);
845         break;
846     case 4:
847         r = gicd_writel(s, offset, data, attrs);
848         break;
849     case 8:
850         r = gicd_writell(s, offset, data, attrs);
851         break;
852     default:
853         r = MEMTX_ERROR;
854         break;
855     }
856 
857     if (r == MEMTX_ERROR) {
858         qemu_log_mask(LOG_GUEST_ERROR,
859                       "%s: invalid guest write at offset " TARGET_FMT_plx
860                       "size %u\n", __func__, offset, size);
861         trace_gicv3_dist_badwrite(offset, data, size, attrs.secure);
862         /* The spec requires that reserved registers are RAZ/WI;
863          * so use MEMTX_ERROR returns from leaf functions as a way to
864          * trigger the guest-error logging but don't return it to
865          * the caller, or we'll cause a spurious guest data abort.
866          */
867         r = MEMTX_OK;
868     } else {
869         trace_gicv3_dist_write(offset, data, size, attrs.secure);
870     }
871     return r;
872 }
873 
874 void gicv3_dist_set_irq(GICv3State *s, int irq, int level)
875 {
876     /* Update distributor state for a change in an external SPI input line */
877     if (level == gicv3_gicd_level_test(s, irq)) {
878         return;
879     }
880 
881     trace_gicv3_dist_set_irq(irq, level);
882 
883     gicv3_gicd_level_replace(s, irq, level);
884 
885     if (level) {
886         /* 0->1 edges latch the pending bit for edge-triggered interrupts */
887         if (gicv3_gicd_edge_trigger_test(s, irq)) {
888             gicv3_gicd_pending_set(s, irq);
889         }
890     }
891 
892     gicv3_update(s, irq, 1);
893 }
894