xref: /openbmc/qemu/hw/ppc/ppc4xx_devs.c (revision 9884abee)
1 /*
2  * QEMU PowerPC 4xx embedded processors shared devices emulation
3  *
4  * Copyright (c) 2007 Jocelyn Mayer
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "qemu/osdep.h"
25 #include "hw/hw.h"
26 #include "hw/ppc/ppc.h"
27 #include "hw/ppc/ppc4xx.h"
28 #include "hw/boards.h"
29 #include "qemu/log.h"
30 #include "exec/address-spaces.h"
31 
32 #define DEBUG_UIC
33 
34 
35 #ifdef DEBUG_UIC
36 #  define LOG_UIC(...) qemu_log_mask(CPU_LOG_INT, ## __VA_ARGS__)
37 #else
38 #  define LOG_UIC(...) do { } while (0)
39 #endif
40 
41 static void ppc4xx_reset(void *opaque)
42 {
43     PowerPCCPU *cpu = opaque;
44 
45     cpu_reset(CPU(cpu));
46 }
47 
48 /*****************************************************************************/
49 /* Generic PowerPC 4xx processor instantiation */
50 PowerPCCPU *ppc4xx_init(const char *cpu_model,
51                         clk_setup_t *cpu_clk, clk_setup_t *tb_clk,
52                         uint32_t sysclk)
53 {
54     PowerPCCPU *cpu;
55     CPUPPCState *env;
56 
57     /* init CPUs */
58     cpu = cpu_ppc_init(cpu_model);
59     if (cpu == NULL) {
60         fprintf(stderr, "Unable to find PowerPC %s CPU definition\n",
61                 cpu_model);
62         exit(1);
63     }
64     env = &cpu->env;
65 
66     cpu_clk->cb = NULL; /* We don't care about CPU clock frequency changes */
67     cpu_clk->opaque = env;
68     /* Set time-base frequency to sysclk */
69     tb_clk->cb = ppc_40x_timers_init(env, sysclk, PPC_INTERRUPT_PIT);
70     tb_clk->opaque = env;
71     ppc_dcr_init(env, NULL, NULL);
72     /* Register qemu callbacks */
73     qemu_register_reset(ppc4xx_reset, cpu);
74 
75     return cpu;
76 }
77 
78 /*****************************************************************************/
79 /* "Universal" Interrupt controller */
80 enum {
81     DCR_UICSR  = 0x000,
82     DCR_UICSRS = 0x001,
83     DCR_UICER  = 0x002,
84     DCR_UICCR  = 0x003,
85     DCR_UICPR  = 0x004,
86     DCR_UICTR  = 0x005,
87     DCR_UICMSR = 0x006,
88     DCR_UICVR  = 0x007,
89     DCR_UICVCR = 0x008,
90     DCR_UICMAX = 0x009,
91 };
92 
93 #define UIC_MAX_IRQ 32
94 typedef struct ppcuic_t ppcuic_t;
95 struct ppcuic_t {
96     uint32_t dcr_base;
97     int use_vectors;
98     uint32_t level;  /* Remembers the state of level-triggered interrupts. */
99     uint32_t uicsr;  /* Status register */
100     uint32_t uicer;  /* Enable register */
101     uint32_t uiccr;  /* Critical register */
102     uint32_t uicpr;  /* Polarity register */
103     uint32_t uictr;  /* Triggering register */
104     uint32_t uicvcr; /* Vector configuration register */
105     uint32_t uicvr;
106     qemu_irq *irqs;
107 };
108 
109 static void ppcuic_trigger_irq (ppcuic_t *uic)
110 {
111     uint32_t ir, cr;
112     int start, end, inc, i;
113 
114     /* Trigger interrupt if any is pending */
115     ir = uic->uicsr & uic->uicer & (~uic->uiccr);
116     cr = uic->uicsr & uic->uicer & uic->uiccr;
117     LOG_UIC("%s: uicsr %08" PRIx32 " uicer %08" PRIx32
118                 " uiccr %08" PRIx32 "\n"
119                 "   %08" PRIx32 " ir %08" PRIx32 " cr %08" PRIx32 "\n",
120                 __func__, uic->uicsr, uic->uicer, uic->uiccr,
121                 uic->uicsr & uic->uicer, ir, cr);
122     if (ir != 0x0000000) {
123         LOG_UIC("Raise UIC interrupt\n");
124         qemu_irq_raise(uic->irqs[PPCUIC_OUTPUT_INT]);
125     } else {
126         LOG_UIC("Lower UIC interrupt\n");
127         qemu_irq_lower(uic->irqs[PPCUIC_OUTPUT_INT]);
128     }
129     /* Trigger critical interrupt if any is pending and update vector */
130     if (cr != 0x0000000) {
131         qemu_irq_raise(uic->irqs[PPCUIC_OUTPUT_CINT]);
132         if (uic->use_vectors) {
133             /* Compute critical IRQ vector */
134             if (uic->uicvcr & 1) {
135                 start = 31;
136                 end = 0;
137                 inc = -1;
138             } else {
139                 start = 0;
140                 end = 31;
141                 inc = 1;
142             }
143             uic->uicvr = uic->uicvcr & 0xFFFFFFFC;
144             for (i = start; i <= end; i += inc) {
145                 if (cr & (1 << i)) {
146                     uic->uicvr += (i - start) * 512 * inc;
147                     break;
148                 }
149             }
150         }
151         LOG_UIC("Raise UIC critical interrupt - "
152                     "vector %08" PRIx32 "\n", uic->uicvr);
153     } else {
154         LOG_UIC("Lower UIC critical interrupt\n");
155         qemu_irq_lower(uic->irqs[PPCUIC_OUTPUT_CINT]);
156         uic->uicvr = 0x00000000;
157     }
158 }
159 
160 static void ppcuic_set_irq (void *opaque, int irq_num, int level)
161 {
162     ppcuic_t *uic;
163     uint32_t mask, sr;
164 
165     uic = opaque;
166     mask = 1U << (31-irq_num);
167     LOG_UIC("%s: irq %d level %d uicsr %08" PRIx32
168                 " mask %08" PRIx32 " => %08" PRIx32 " %08" PRIx32 "\n",
169                 __func__, irq_num, level,
170                 uic->uicsr, mask, uic->uicsr & mask, level << irq_num);
171     if (irq_num < 0 || irq_num > 31)
172         return;
173     sr = uic->uicsr;
174 
175     /* Update status register */
176     if (uic->uictr & mask) {
177         /* Edge sensitive interrupt */
178         if (level == 1)
179             uic->uicsr |= mask;
180     } else {
181         /* Level sensitive interrupt */
182         if (level == 1) {
183             uic->uicsr |= mask;
184             uic->level |= mask;
185         } else {
186             uic->uicsr &= ~mask;
187             uic->level &= ~mask;
188         }
189     }
190     LOG_UIC("%s: irq %d level %d sr %" PRIx32 " => "
191                 "%08" PRIx32 "\n", __func__, irq_num, level, uic->uicsr, sr);
192     if (sr != uic->uicsr)
193         ppcuic_trigger_irq(uic);
194 }
195 
196 static uint32_t dcr_read_uic (void *opaque, int dcrn)
197 {
198     ppcuic_t *uic;
199     uint32_t ret;
200 
201     uic = opaque;
202     dcrn -= uic->dcr_base;
203     switch (dcrn) {
204     case DCR_UICSR:
205     case DCR_UICSRS:
206         ret = uic->uicsr;
207         break;
208     case DCR_UICER:
209         ret = uic->uicer;
210         break;
211     case DCR_UICCR:
212         ret = uic->uiccr;
213         break;
214     case DCR_UICPR:
215         ret = uic->uicpr;
216         break;
217     case DCR_UICTR:
218         ret = uic->uictr;
219         break;
220     case DCR_UICMSR:
221         ret = uic->uicsr & uic->uicer;
222         break;
223     case DCR_UICVR:
224         if (!uic->use_vectors)
225             goto no_read;
226         ret = uic->uicvr;
227         break;
228     case DCR_UICVCR:
229         if (!uic->use_vectors)
230             goto no_read;
231         ret = uic->uicvcr;
232         break;
233     default:
234     no_read:
235         ret = 0x00000000;
236         break;
237     }
238 
239     return ret;
240 }
241 
242 static void dcr_write_uic (void *opaque, int dcrn, uint32_t val)
243 {
244     ppcuic_t *uic;
245 
246     uic = opaque;
247     dcrn -= uic->dcr_base;
248     LOG_UIC("%s: dcr %d val 0x%x\n", __func__, dcrn, val);
249     switch (dcrn) {
250     case DCR_UICSR:
251         uic->uicsr &= ~val;
252         uic->uicsr |= uic->level;
253         ppcuic_trigger_irq(uic);
254         break;
255     case DCR_UICSRS:
256         uic->uicsr |= val;
257         ppcuic_trigger_irq(uic);
258         break;
259     case DCR_UICER:
260         uic->uicer = val;
261         ppcuic_trigger_irq(uic);
262         break;
263     case DCR_UICCR:
264         uic->uiccr = val;
265         ppcuic_trigger_irq(uic);
266         break;
267     case DCR_UICPR:
268         uic->uicpr = val;
269         break;
270     case DCR_UICTR:
271         uic->uictr = val;
272         ppcuic_trigger_irq(uic);
273         break;
274     case DCR_UICMSR:
275         break;
276     case DCR_UICVR:
277         break;
278     case DCR_UICVCR:
279         uic->uicvcr = val & 0xFFFFFFFD;
280         ppcuic_trigger_irq(uic);
281         break;
282     }
283 }
284 
285 static void ppcuic_reset (void *opaque)
286 {
287     ppcuic_t *uic;
288 
289     uic = opaque;
290     uic->uiccr = 0x00000000;
291     uic->uicer = 0x00000000;
292     uic->uicpr = 0x00000000;
293     uic->uicsr = 0x00000000;
294     uic->uictr = 0x00000000;
295     if (uic->use_vectors) {
296         uic->uicvcr = 0x00000000;
297         uic->uicvr = 0x0000000;
298     }
299 }
300 
301 qemu_irq *ppcuic_init (CPUPPCState *env, qemu_irq *irqs,
302                        uint32_t dcr_base, int has_ssr, int has_vr)
303 {
304     ppcuic_t *uic;
305     int i;
306 
307     uic = g_malloc0(sizeof(ppcuic_t));
308     uic->dcr_base = dcr_base;
309     uic->irqs = irqs;
310     if (has_vr)
311         uic->use_vectors = 1;
312     for (i = 0; i < DCR_UICMAX; i++) {
313         ppc_dcr_register(env, dcr_base + i, uic,
314                          &dcr_read_uic, &dcr_write_uic);
315     }
316     qemu_register_reset(ppcuic_reset, uic);
317 
318     return qemu_allocate_irqs(&ppcuic_set_irq, uic, UIC_MAX_IRQ);
319 }
320 
321 /*****************************************************************************/
322 /* SDRAM controller */
323 typedef struct ppc4xx_sdram_t ppc4xx_sdram_t;
324 struct ppc4xx_sdram_t {
325     uint32_t addr;
326     int nbanks;
327     MemoryRegion containers[4]; /* used for clipping */
328     MemoryRegion *ram_memories;
329     hwaddr ram_bases[4];
330     hwaddr ram_sizes[4];
331     uint32_t besr0;
332     uint32_t besr1;
333     uint32_t bear;
334     uint32_t cfg;
335     uint32_t status;
336     uint32_t rtr;
337     uint32_t pmit;
338     uint32_t bcr[4];
339     uint32_t tr;
340     uint32_t ecccfg;
341     uint32_t eccesr;
342     qemu_irq irq;
343 };
344 
345 enum {
346     SDRAM0_CFGADDR = 0x010,
347     SDRAM0_CFGDATA = 0x011,
348 };
349 
350 /* XXX: TOFIX: some patches have made this code become inconsistent:
351  *      there are type inconsistencies, mixing hwaddr, target_ulong
352  *      and uint32_t
353  */
354 static uint32_t sdram_bcr (hwaddr ram_base,
355                            hwaddr ram_size)
356 {
357     uint32_t bcr;
358 
359     switch (ram_size) {
360     case (4 * 1024 * 1024):
361         bcr = 0x00000000;
362         break;
363     case (8 * 1024 * 1024):
364         bcr = 0x00020000;
365         break;
366     case (16 * 1024 * 1024):
367         bcr = 0x00040000;
368         break;
369     case (32 * 1024 * 1024):
370         bcr = 0x00060000;
371         break;
372     case (64 * 1024 * 1024):
373         bcr = 0x00080000;
374         break;
375     case (128 * 1024 * 1024):
376         bcr = 0x000A0000;
377         break;
378     case (256 * 1024 * 1024):
379         bcr = 0x000C0000;
380         break;
381     default:
382         printf("%s: invalid RAM size " TARGET_FMT_plx "\n", __func__,
383                ram_size);
384         return 0x00000000;
385     }
386     bcr |= ram_base & 0xFF800000;
387     bcr |= 1;
388 
389     return bcr;
390 }
391 
392 static inline hwaddr sdram_base(uint32_t bcr)
393 {
394     return bcr & 0xFF800000;
395 }
396 
397 static target_ulong sdram_size (uint32_t bcr)
398 {
399     target_ulong size;
400     int sh;
401 
402     sh = (bcr >> 17) & 0x7;
403     if (sh == 7)
404         size = -1;
405     else
406         size = (4 * 1024 * 1024) << sh;
407 
408     return size;
409 }
410 
411 static void sdram_set_bcr(ppc4xx_sdram_t *sdram,
412                           uint32_t *bcrp, uint32_t bcr, int enabled)
413 {
414     unsigned n = bcrp - sdram->bcr;
415 
416     if (*bcrp & 0x00000001) {
417         /* Unmap RAM */
418 #ifdef DEBUG_SDRAM
419         printf("%s: unmap RAM area " TARGET_FMT_plx " " TARGET_FMT_lx "\n",
420                __func__, sdram_base(*bcrp), sdram_size(*bcrp));
421 #endif
422         memory_region_del_subregion(get_system_memory(),
423                                     &sdram->containers[n]);
424         memory_region_del_subregion(&sdram->containers[n],
425                                     &sdram->ram_memories[n]);
426         object_unparent(OBJECT(&sdram->containers[n]));
427     }
428     *bcrp = bcr & 0xFFDEE001;
429     if (enabled && (bcr & 0x00000001)) {
430 #ifdef DEBUG_SDRAM
431         printf("%s: Map RAM area " TARGET_FMT_plx " " TARGET_FMT_lx "\n",
432                __func__, sdram_base(bcr), sdram_size(bcr));
433 #endif
434         memory_region_init(&sdram->containers[n], NULL, "sdram-containers",
435                            sdram_size(bcr));
436         memory_region_add_subregion(&sdram->containers[n], 0,
437                                     &sdram->ram_memories[n]);
438         memory_region_add_subregion(get_system_memory(),
439                                     sdram_base(bcr),
440                                     &sdram->containers[n]);
441     }
442 }
443 
444 static void sdram_map_bcr (ppc4xx_sdram_t *sdram)
445 {
446     int i;
447 
448     for (i = 0; i < sdram->nbanks; i++) {
449         if (sdram->ram_sizes[i] != 0) {
450             sdram_set_bcr(sdram,
451                           &sdram->bcr[i],
452                           sdram_bcr(sdram->ram_bases[i], sdram->ram_sizes[i]),
453                           1);
454         } else {
455             sdram_set_bcr(sdram, &sdram->bcr[i], 0x00000000, 0);
456         }
457     }
458 }
459 
460 static void sdram_unmap_bcr (ppc4xx_sdram_t *sdram)
461 {
462     int i;
463 
464     for (i = 0; i < sdram->nbanks; i++) {
465 #ifdef DEBUG_SDRAM
466         printf("%s: Unmap RAM area " TARGET_FMT_plx " " TARGET_FMT_lx "\n",
467                __func__, sdram_base(sdram->bcr[i]), sdram_size(sdram->bcr[i]));
468 #endif
469         memory_region_del_subregion(get_system_memory(),
470                                     &sdram->ram_memories[i]);
471     }
472 }
473 
474 static uint32_t dcr_read_sdram (void *opaque, int dcrn)
475 {
476     ppc4xx_sdram_t *sdram;
477     uint32_t ret;
478 
479     sdram = opaque;
480     switch (dcrn) {
481     case SDRAM0_CFGADDR:
482         ret = sdram->addr;
483         break;
484     case SDRAM0_CFGDATA:
485         switch (sdram->addr) {
486         case 0x00: /* SDRAM_BESR0 */
487             ret = sdram->besr0;
488             break;
489         case 0x08: /* SDRAM_BESR1 */
490             ret = sdram->besr1;
491             break;
492         case 0x10: /* SDRAM_BEAR */
493             ret = sdram->bear;
494             break;
495         case 0x20: /* SDRAM_CFG */
496             ret = sdram->cfg;
497             break;
498         case 0x24: /* SDRAM_STATUS */
499             ret = sdram->status;
500             break;
501         case 0x30: /* SDRAM_RTR */
502             ret = sdram->rtr;
503             break;
504         case 0x34: /* SDRAM_PMIT */
505             ret = sdram->pmit;
506             break;
507         case 0x40: /* SDRAM_B0CR */
508             ret = sdram->bcr[0];
509             break;
510         case 0x44: /* SDRAM_B1CR */
511             ret = sdram->bcr[1];
512             break;
513         case 0x48: /* SDRAM_B2CR */
514             ret = sdram->bcr[2];
515             break;
516         case 0x4C: /* SDRAM_B3CR */
517             ret = sdram->bcr[3];
518             break;
519         case 0x80: /* SDRAM_TR */
520             ret = -1; /* ? */
521             break;
522         case 0x94: /* SDRAM_ECCCFG */
523             ret = sdram->ecccfg;
524             break;
525         case 0x98: /* SDRAM_ECCESR */
526             ret = sdram->eccesr;
527             break;
528         default: /* Error */
529             ret = -1;
530             break;
531         }
532         break;
533     default:
534         /* Avoid gcc warning */
535         ret = 0x00000000;
536         break;
537     }
538 
539     return ret;
540 }
541 
542 static void dcr_write_sdram (void *opaque, int dcrn, uint32_t val)
543 {
544     ppc4xx_sdram_t *sdram;
545 
546     sdram = opaque;
547     switch (dcrn) {
548     case SDRAM0_CFGADDR:
549         sdram->addr = val;
550         break;
551     case SDRAM0_CFGDATA:
552         switch (sdram->addr) {
553         case 0x00: /* SDRAM_BESR0 */
554             sdram->besr0 &= ~val;
555             break;
556         case 0x08: /* SDRAM_BESR1 */
557             sdram->besr1 &= ~val;
558             break;
559         case 0x10: /* SDRAM_BEAR */
560             sdram->bear = val;
561             break;
562         case 0x20: /* SDRAM_CFG */
563             val &= 0xFFE00000;
564             if (!(sdram->cfg & 0x80000000) && (val & 0x80000000)) {
565 #ifdef DEBUG_SDRAM
566                 printf("%s: enable SDRAM controller\n", __func__);
567 #endif
568                 /* validate all RAM mappings */
569                 sdram_map_bcr(sdram);
570                 sdram->status &= ~0x80000000;
571             } else if ((sdram->cfg & 0x80000000) && !(val & 0x80000000)) {
572 #ifdef DEBUG_SDRAM
573                 printf("%s: disable SDRAM controller\n", __func__);
574 #endif
575                 /* invalidate all RAM mappings */
576                 sdram_unmap_bcr(sdram);
577                 sdram->status |= 0x80000000;
578             }
579             if (!(sdram->cfg & 0x40000000) && (val & 0x40000000))
580                 sdram->status |= 0x40000000;
581             else if ((sdram->cfg & 0x40000000) && !(val & 0x40000000))
582                 sdram->status &= ~0x40000000;
583             sdram->cfg = val;
584             break;
585         case 0x24: /* SDRAM_STATUS */
586             /* Read-only register */
587             break;
588         case 0x30: /* SDRAM_RTR */
589             sdram->rtr = val & 0x3FF80000;
590             break;
591         case 0x34: /* SDRAM_PMIT */
592             sdram->pmit = (val & 0xF8000000) | 0x07C00000;
593             break;
594         case 0x40: /* SDRAM_B0CR */
595             sdram_set_bcr(sdram, &sdram->bcr[0], val, sdram->cfg & 0x80000000);
596             break;
597         case 0x44: /* SDRAM_B1CR */
598             sdram_set_bcr(sdram, &sdram->bcr[1], val, sdram->cfg & 0x80000000);
599             break;
600         case 0x48: /* SDRAM_B2CR */
601             sdram_set_bcr(sdram, &sdram->bcr[2], val, sdram->cfg & 0x80000000);
602             break;
603         case 0x4C: /* SDRAM_B3CR */
604             sdram_set_bcr(sdram, &sdram->bcr[3], val, sdram->cfg & 0x80000000);
605             break;
606         case 0x80: /* SDRAM_TR */
607             sdram->tr = val & 0x018FC01F;
608             break;
609         case 0x94: /* SDRAM_ECCCFG */
610             sdram->ecccfg = val & 0x00F00000;
611             break;
612         case 0x98: /* SDRAM_ECCESR */
613             val &= 0xFFF0F000;
614             if (sdram->eccesr == 0 && val != 0)
615                 qemu_irq_raise(sdram->irq);
616             else if (sdram->eccesr != 0 && val == 0)
617                 qemu_irq_lower(sdram->irq);
618             sdram->eccesr = val;
619             break;
620         default: /* Error */
621             break;
622         }
623         break;
624     }
625 }
626 
627 static void sdram_reset (void *opaque)
628 {
629     ppc4xx_sdram_t *sdram;
630 
631     sdram = opaque;
632     sdram->addr = 0x00000000;
633     sdram->bear = 0x00000000;
634     sdram->besr0 = 0x00000000; /* No error */
635     sdram->besr1 = 0x00000000; /* No error */
636     sdram->cfg = 0x00000000;
637     sdram->ecccfg = 0x00000000; /* No ECC */
638     sdram->eccesr = 0x00000000; /* No error */
639     sdram->pmit = 0x07C00000;
640     sdram->rtr = 0x05F00000;
641     sdram->tr = 0x00854009;
642     /* We pre-initialize RAM banks */
643     sdram->status = 0x00000000;
644     sdram->cfg = 0x00800000;
645 }
646 
647 void ppc4xx_sdram_init (CPUPPCState *env, qemu_irq irq, int nbanks,
648                         MemoryRegion *ram_memories,
649                         hwaddr *ram_bases,
650                         hwaddr *ram_sizes,
651                         int do_init)
652 {
653     ppc4xx_sdram_t *sdram;
654 
655     sdram = g_malloc0(sizeof(ppc4xx_sdram_t));
656     sdram->irq = irq;
657     sdram->nbanks = nbanks;
658     sdram->ram_memories = ram_memories;
659     memset(sdram->ram_bases, 0, 4 * sizeof(hwaddr));
660     memcpy(sdram->ram_bases, ram_bases,
661            nbanks * sizeof(hwaddr));
662     memset(sdram->ram_sizes, 0, 4 * sizeof(hwaddr));
663     memcpy(sdram->ram_sizes, ram_sizes,
664            nbanks * sizeof(hwaddr));
665     qemu_register_reset(&sdram_reset, sdram);
666     ppc_dcr_register(env, SDRAM0_CFGADDR,
667                      sdram, &dcr_read_sdram, &dcr_write_sdram);
668     ppc_dcr_register(env, SDRAM0_CFGDATA,
669                      sdram, &dcr_read_sdram, &dcr_write_sdram);
670     if (do_init)
671         sdram_map_bcr(sdram);
672 }
673 
674 /* Fill in consecutive SDRAM banks with 'ram_size' bytes of memory.
675  *
676  * sdram_bank_sizes[] must be 0-terminated.
677  *
678  * The 4xx SDRAM controller supports a small number of banks, and each bank
679  * must be one of a small set of sizes. The number of banks and the supported
680  * sizes varies by SoC. */
681 ram_addr_t ppc4xx_sdram_adjust(ram_addr_t ram_size, int nr_banks,
682                                MemoryRegion ram_memories[],
683                                hwaddr ram_bases[],
684                                hwaddr ram_sizes[],
685                                const unsigned int sdram_bank_sizes[])
686 {
687     MemoryRegion *ram = g_malloc0(sizeof(*ram));
688     ram_addr_t size_left = ram_size;
689     ram_addr_t base = 0;
690     unsigned int bank_size;
691     int i;
692     int j;
693 
694     for (i = 0; i < nr_banks; i++) {
695         for (j = 0; sdram_bank_sizes[j] != 0; j++) {
696             bank_size = sdram_bank_sizes[j];
697             if (bank_size <= size_left) {
698                 size_left -= bank_size;
699             }
700         }
701         if (!size_left) {
702             /* No need to use the remaining banks. */
703             break;
704         }
705     }
706 
707     ram_size -= size_left;
708     if (size_left) {
709         printf("Truncating memory to %d MiB to fit SDRAM controller limits.\n",
710                (int)(ram_size >> 20));
711     }
712 
713     memory_region_allocate_system_memory(ram, NULL, "ppc4xx.sdram", ram_size);
714 
715     size_left = ram_size;
716     for (i = 0; i < nr_banks && size_left; i++) {
717         for (j = 0; sdram_bank_sizes[j] != 0; j++) {
718             bank_size = sdram_bank_sizes[j];
719 
720             if (bank_size <= size_left) {
721                 char name[32];
722                 snprintf(name, sizeof(name), "ppc4xx.sdram%d", i);
723                 memory_region_init_alias(&ram_memories[i], NULL, name, ram,
724                                          base, bank_size);
725                 ram_bases[i] = base;
726                 ram_sizes[i] = bank_size;
727                 base += bank_size;
728                 size_left -= bank_size;
729                 break;
730             }
731         }
732     }
733 
734     return ram_size;
735 }
736