nohz: prevent tick stop outside of the idle loop
[linux-2.6.git] / arch / powerpc / platforms / iseries / setup.c
1 /*
2  *    Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
3  *    Copyright (c) 1999-2000 Grant Erickson <grant@lcse.umn.edu>
4  *
5  *    Description:
6  *      Architecture- / platform-specific boot-time initialization code for
7  *      the IBM iSeries LPAR.  Adapted from original code by Grant Erickson and
8  *      code by Gary Thomas, Cort Dougan <cort@fsmlabs.com>, and Dan Malek
9  *      <dan@net4x.com>.
10  *
11  *      This program is free software; you can redistribute it and/or
12  *      modify it under the terms of the GNU General Public License
13  *      as published by the Free Software Foundation; either version
14  *      2 of the License, or (at your option) any later version.
15  */
16
17 #undef DEBUG
18
19 #include <linux/init.h>
20 #include <linux/threads.h>
21 #include <linux/smp.h>
22 #include <linux/param.h>
23 #include <linux/string.h>
24 #include <linux/seq_file.h>
25 #include <linux/kdev_t.h>
26 #include <linux/major.h>
27 #include <linux/root_dev.h>
28 #include <linux/kernel.h>
29 #include <linux/hrtimer.h>
30 #include <linux/tick.h>
31
32 #include <asm/processor.h>
33 #include <asm/machdep.h>
34 #include <asm/page.h>
35 #include <asm/mmu.h>
36 #include <asm/pgtable.h>
37 #include <asm/mmu_context.h>
38 #include <asm/cputable.h>
39 #include <asm/sections.h>
40 #include <asm/iommu.h>
41 #include <asm/firmware.h>
42 #include <asm/system.h>
43 #include <asm/time.h>
44 #include <asm/paca.h>
45 #include <asm/cache.h>
46 #include <asm/abs_addr.h>
47 #include <asm/iseries/hv_lp_config.h>
48 #include <asm/iseries/hv_call_event.h>
49 #include <asm/iseries/hv_call_xm.h>
50 #include <asm/iseries/it_lp_queue.h>
51 #include <asm/iseries/mf.h>
52 #include <asm/iseries/hv_lp_event.h>
53 #include <asm/iseries/lpar_map.h>
54 #include <asm/udbg.h>
55 #include <asm/irq.h>
56
57 #include "naca.h"
58 #include "setup.h"
59 #include "irq.h"
60 #include "vpd_areas.h"
61 #include "processor_vpd.h"
62 #include "it_lp_naca.h"
63 #include "main_store.h"
64 #include "call_sm.h"
65 #include "call_hpt.h"
66 #include "pci.h"
67
68 #ifdef DEBUG
69 #define DBG(fmt...) udbg_printf(fmt)
70 #else
71 #define DBG(fmt...)
72 #endif
73
74 /* Function Prototypes */
75 static unsigned long build_iSeries_Memory_Map(void);
76 static void iseries_shared_idle(void);
77 static void iseries_dedicated_idle(void);
78
79
80 struct MemoryBlock {
81         unsigned long absStart;
82         unsigned long absEnd;
83         unsigned long logicalStart;
84         unsigned long logicalEnd;
85 };
86
87 /*
88  * Process the main store vpd to determine where the holes in memory are
89  * and return the number of physical blocks and fill in the array of
90  * block data.
91  */
92 static unsigned long iSeries_process_Condor_mainstore_vpd(
93                 struct MemoryBlock *mb_array, unsigned long max_entries)
94 {
95         unsigned long holeFirstChunk, holeSizeChunks;
96         unsigned long numMemoryBlocks = 1;
97         struct IoHriMainStoreSegment4 *msVpd =
98                 (struct IoHriMainStoreSegment4 *)xMsVpd;
99         unsigned long holeStart = msVpd->nonInterleavedBlocksStartAdr;
100         unsigned long holeEnd = msVpd->nonInterleavedBlocksEndAdr;
101         unsigned long holeSize = holeEnd - holeStart;
102
103         printk("Mainstore_VPD: Condor\n");
104         /*
105          * Determine if absolute memory has any
106          * holes so that we can interpret the
107          * access map we get back from the hypervisor
108          * correctly.
109          */
110         mb_array[0].logicalStart = 0;
111         mb_array[0].logicalEnd = 0x100000000UL;
112         mb_array[0].absStart = 0;
113         mb_array[0].absEnd = 0x100000000UL;
114
115         if (holeSize) {
116                 numMemoryBlocks = 2;
117                 holeStart = holeStart & 0x000fffffffffffffUL;
118                 holeStart = addr_to_chunk(holeStart);
119                 holeFirstChunk = holeStart;
120                 holeSize = addr_to_chunk(holeSize);
121                 holeSizeChunks = holeSize;
122                 printk( "Main store hole: start chunk = %0lx, size = %0lx chunks\n",
123                                 holeFirstChunk, holeSizeChunks );
124                 mb_array[0].logicalEnd = holeFirstChunk;
125                 mb_array[0].absEnd = holeFirstChunk;
126                 mb_array[1].logicalStart = holeFirstChunk;
127                 mb_array[1].logicalEnd = 0x100000000UL - holeSizeChunks;
128                 mb_array[1].absStart = holeFirstChunk + holeSizeChunks;
129                 mb_array[1].absEnd = 0x100000000UL;
130         }
131         return numMemoryBlocks;
132 }
133
134 #define MaxSegmentAreas                 32
135 #define MaxSegmentAdrRangeBlocks        128
136 #define MaxAreaRangeBlocks              4
137
138 static unsigned long iSeries_process_Regatta_mainstore_vpd(
139                 struct MemoryBlock *mb_array, unsigned long max_entries)
140 {
141         struct IoHriMainStoreSegment5 *msVpdP =
142                 (struct IoHriMainStoreSegment5 *)xMsVpd;
143         unsigned long numSegmentBlocks = 0;
144         u32 existsBits = msVpdP->msAreaExists;
145         unsigned long area_num;
146
147         printk("Mainstore_VPD: Regatta\n");
148
149         for (area_num = 0; area_num < MaxSegmentAreas; ++area_num ) {
150                 unsigned long numAreaBlocks;
151                 struct IoHriMainStoreArea4 *currentArea;
152
153                 if (existsBits & 0x80000000) {
154                         unsigned long block_num;
155
156                         currentArea = &msVpdP->msAreaArray[area_num];
157                         numAreaBlocks = currentArea->numAdrRangeBlocks;
158                         printk("ms_vpd: processing area %2ld  blocks=%ld",
159                                         area_num, numAreaBlocks);
160                         for (block_num = 0; block_num < numAreaBlocks;
161                                         ++block_num ) {
162                                 /* Process an address range block */
163                                 struct MemoryBlock tempBlock;
164                                 unsigned long i;
165
166                                 tempBlock.absStart =
167                                         (unsigned long)currentArea->xAdrRangeBlock[block_num].blockStart;
168                                 tempBlock.absEnd =
169                                         (unsigned long)currentArea->xAdrRangeBlock[block_num].blockEnd;
170                                 tempBlock.logicalStart = 0;
171                                 tempBlock.logicalEnd   = 0;
172                                 printk("\n          block %ld absStart=%016lx absEnd=%016lx",
173                                                 block_num, tempBlock.absStart,
174                                                 tempBlock.absEnd);
175
176                                 for (i = 0; i < numSegmentBlocks; ++i) {
177                                         if (mb_array[i].absStart ==
178                                                         tempBlock.absStart)
179                                                 break;
180                                 }
181                                 if (i == numSegmentBlocks) {
182                                         if (numSegmentBlocks == max_entries)
183                                                 panic("iSeries_process_mainstore_vpd: too many memory blocks");
184                                         mb_array[numSegmentBlocks] = tempBlock;
185                                         ++numSegmentBlocks;
186                                 } else
187                                         printk(" (duplicate)");
188                         }
189                         printk("\n");
190                 }
191                 existsBits <<= 1;
192         }
193         /* Now sort the blocks found into ascending sequence */
194         if (numSegmentBlocks > 1) {
195                 unsigned long m, n;
196
197                 for (m = 0; m < numSegmentBlocks - 1; ++m) {
198                         for (n = numSegmentBlocks - 1; m < n; --n) {
199                                 if (mb_array[n].absStart <
200                                                 mb_array[n-1].absStart) {
201                                         struct MemoryBlock tempBlock;
202
203                                         tempBlock = mb_array[n];
204                                         mb_array[n] = mb_array[n-1];
205                                         mb_array[n-1] = tempBlock;
206                                 }
207                         }
208                 }
209         }
210         /*
211          * Assign "logical" addresses to each block.  These
212          * addresses correspond to the hypervisor "bitmap" space.
213          * Convert all addresses into units of 256K chunks.
214          */
215         {
216         unsigned long i, nextBitmapAddress;
217
218         printk("ms_vpd: %ld sorted memory blocks\n", numSegmentBlocks);
219         nextBitmapAddress = 0;
220         for (i = 0; i < numSegmentBlocks; ++i) {
221                 unsigned long length = mb_array[i].absEnd -
222                         mb_array[i].absStart;
223
224                 mb_array[i].logicalStart = nextBitmapAddress;
225                 mb_array[i].logicalEnd = nextBitmapAddress + length;
226                 nextBitmapAddress += length;
227                 printk("          Bitmap range: %016lx - %016lx\n"
228                                 "        Absolute range: %016lx - %016lx\n",
229                                 mb_array[i].logicalStart,
230                                 mb_array[i].logicalEnd,
231                                 mb_array[i].absStart, mb_array[i].absEnd);
232                 mb_array[i].absStart = addr_to_chunk(mb_array[i].absStart &
233                                 0x000fffffffffffffUL);
234                 mb_array[i].absEnd = addr_to_chunk(mb_array[i].absEnd &
235                                 0x000fffffffffffffUL);
236                 mb_array[i].logicalStart =
237                         addr_to_chunk(mb_array[i].logicalStart);
238                 mb_array[i].logicalEnd = addr_to_chunk(mb_array[i].logicalEnd);
239         }
240         }
241
242         return numSegmentBlocks;
243 }
244
245 static unsigned long iSeries_process_mainstore_vpd(struct MemoryBlock *mb_array,
246                 unsigned long max_entries)
247 {
248         unsigned long i;
249         unsigned long mem_blocks = 0;
250
251         if (cpu_has_feature(CPU_FTR_SLB))
252                 mem_blocks = iSeries_process_Regatta_mainstore_vpd(mb_array,
253                                 max_entries);
254         else
255                 mem_blocks = iSeries_process_Condor_mainstore_vpd(mb_array,
256                                 max_entries);
257
258         printk("Mainstore_VPD: numMemoryBlocks = %ld \n", mem_blocks);
259         for (i = 0; i < mem_blocks; ++i) {
260                 printk("Mainstore_VPD: block %3ld logical chunks %016lx - %016lx\n"
261                        "                             abs chunks %016lx - %016lx\n",
262                         i, mb_array[i].logicalStart, mb_array[i].logicalEnd,
263                         mb_array[i].absStart, mb_array[i].absEnd);
264         }
265         return mem_blocks;
266 }
267
268 static void __init iSeries_get_cmdline(void)
269 {
270         char *p, *q;
271
272         /* copy the command line parameter from the primary VSP  */
273         HvCallEvent_dmaToSp(cmd_line, 2 * 64* 1024, 256,
274                         HvLpDma_Direction_RemoteToLocal);
275
276         p = cmd_line;
277         q = cmd_line + 255;
278         while(p < q) {
279                 if (!*p || *p == '\n')
280                         break;
281                 ++p;
282         }
283         *p = 0;
284 }
285
286 static void __init iSeries_init_early(void)
287 {
288         DBG(" -> iSeries_init_early()\n");
289
290         /* Snapshot the timebase, for use in later recalibration */
291         iSeries_time_init_early();
292
293         /*
294          * Initialize the DMA/TCE management
295          */
296         iommu_init_early_iSeries();
297
298         /* Initialize machine-dependency vectors */
299 #ifdef CONFIG_SMP
300         smp_init_iSeries();
301 #endif
302
303         /* Associate Lp Event Queue 0 with processor 0 */
304         HvCallEvent_setLpEventQueueInterruptProc(0, 0);
305
306         mf_init();
307
308         DBG(" <- iSeries_init_early()\n");
309 }
310
311 struct mschunks_map mschunks_map = {
312         /* XXX We don't use these, but Piranha might need them. */
313         .chunk_size  = MSCHUNKS_CHUNK_SIZE,
314         .chunk_shift = MSCHUNKS_CHUNK_SHIFT,
315         .chunk_mask  = MSCHUNKS_OFFSET_MASK,
316 };
317 EXPORT_SYMBOL(mschunks_map);
318
319 static void mschunks_alloc(unsigned long num_chunks)
320 {
321         klimit = _ALIGN(klimit, sizeof(u32));
322         mschunks_map.mapping = (u32 *)klimit;
323         klimit += num_chunks * sizeof(u32);
324         mschunks_map.num_chunks = num_chunks;
325 }
326
327 /*
328  * The iSeries may have very large memories ( > 128 GB ) and a partition
329  * may get memory in "chunks" that may be anywhere in the 2**52 real
330  * address space.  The chunks are 256K in size.  To map this to the
331  * memory model Linux expects, the AS/400 specific code builds a
332  * translation table to translate what Linux thinks are "physical"
333  * addresses to the actual real addresses.  This allows us to make
334  * it appear to Linux that we have contiguous memory starting at
335  * physical address zero while in fact this could be far from the truth.
336  * To avoid confusion, I'll let the words physical and/or real address
337  * apply to the Linux addresses while I'll use "absolute address" to
338  * refer to the actual hardware real address.
339  *
340  * build_iSeries_Memory_Map gets information from the Hypervisor and
341  * looks at the Main Store VPD to determine the absolute addresses
342  * of the memory that has been assigned to our partition and builds
343  * a table used to translate Linux's physical addresses to these
344  * absolute addresses.  Absolute addresses are needed when
345  * communicating with the hypervisor (e.g. to build HPT entries)
346  *
347  * Returns the physical memory size
348  */
349
350 static unsigned long __init build_iSeries_Memory_Map(void)
351 {
352         u32 loadAreaFirstChunk, loadAreaLastChunk, loadAreaSize;
353         u32 nextPhysChunk;
354         u32 hptFirstChunk, hptLastChunk, hptSizeChunks, hptSizePages;
355         u32 totalChunks,moreChunks;
356         u32 currChunk, thisChunk, absChunk;
357         u32 currDword;
358         u32 chunkBit;
359         u64 map;
360         struct MemoryBlock mb[32];
361         unsigned long numMemoryBlocks, curBlock;
362
363         /* Chunk size on iSeries is 256K bytes */
364         totalChunks = (u32)HvLpConfig_getMsChunks();
365         mschunks_alloc(totalChunks);
366
367         /*
368          * Get absolute address of our load area
369          * and map it to physical address 0
370          * This guarantees that the loadarea ends up at physical 0
371          * otherwise, it might not be returned by PLIC as the first
372          * chunks
373          */
374
375         loadAreaFirstChunk = (u32)addr_to_chunk(itLpNaca.xLoadAreaAddr);
376         loadAreaSize =  itLpNaca.xLoadAreaChunks;
377
378         /*
379          * Only add the pages already mapped here.
380          * Otherwise we might add the hpt pages
381          * The rest of the pages of the load area
382          * aren't in the HPT yet and can still
383          * be assigned an arbitrary physical address
384          */
385         if ((loadAreaSize * 64) > HvPagesToMap)
386                 loadAreaSize = HvPagesToMap / 64;
387
388         loadAreaLastChunk = loadAreaFirstChunk + loadAreaSize - 1;
389
390         /*
391          * TODO Do we need to do something if the HPT is in the 64MB load area?
392          * This would be required if the itLpNaca.xLoadAreaChunks includes
393          * the HPT size
394          */
395
396         printk("Mapping load area - physical addr = 0000000000000000\n"
397                 "                    absolute addr = %016lx\n",
398                 chunk_to_addr(loadAreaFirstChunk));
399         printk("Load area size %dK\n", loadAreaSize * 256);
400
401         for (nextPhysChunk = 0; nextPhysChunk < loadAreaSize; ++nextPhysChunk)
402                 mschunks_map.mapping[nextPhysChunk] =
403                         loadAreaFirstChunk + nextPhysChunk;
404
405         /*
406          * Get absolute address of our HPT and remember it so
407          * we won't map it to any physical address
408          */
409         hptFirstChunk = (u32)addr_to_chunk(HvCallHpt_getHptAddress());
410         hptSizePages = (u32)HvCallHpt_getHptPages();
411         hptSizeChunks = hptSizePages >>
412                 (MSCHUNKS_CHUNK_SHIFT - HW_PAGE_SHIFT);
413         hptLastChunk = hptFirstChunk + hptSizeChunks - 1;
414
415         printk("HPT absolute addr = %016lx, size = %dK\n",
416                         chunk_to_addr(hptFirstChunk), hptSizeChunks * 256);
417
418         /*
419          * Determine if absolute memory has any
420          * holes so that we can interpret the
421          * access map we get back from the hypervisor
422          * correctly.
423          */
424         numMemoryBlocks = iSeries_process_mainstore_vpd(mb, 32);
425
426         /*
427          * Process the main store access map from the hypervisor
428          * to build up our physical -> absolute translation table
429          */
430         curBlock = 0;
431         currChunk = 0;
432         currDword = 0;
433         moreChunks = totalChunks;
434
435         while (moreChunks) {
436                 map = HvCallSm_get64BitsOfAccessMap(itLpNaca.xLpIndex,
437                                 currDword);
438                 thisChunk = currChunk;
439                 while (map) {
440                         chunkBit = map >> 63;
441                         map <<= 1;
442                         if (chunkBit) {
443                                 --moreChunks;
444                                 while (thisChunk >= mb[curBlock].logicalEnd) {
445                                         ++curBlock;
446                                         if (curBlock >= numMemoryBlocks)
447                                                 panic("out of memory blocks");
448                                 }
449                                 if (thisChunk < mb[curBlock].logicalStart)
450                                         panic("memory block error");
451
452                                 absChunk = mb[curBlock].absStart +
453                                         (thisChunk - mb[curBlock].logicalStart);
454                                 if (((absChunk < hptFirstChunk) ||
455                                      (absChunk > hptLastChunk)) &&
456                                     ((absChunk < loadAreaFirstChunk) ||
457                                      (absChunk > loadAreaLastChunk))) {
458                                         mschunks_map.mapping[nextPhysChunk] =
459                                                 absChunk;
460                                         ++nextPhysChunk;
461                                 }
462                         }
463                         ++thisChunk;
464                 }
465                 ++currDword;
466                 currChunk += 64;
467         }
468
469         /*
470          * main store size (in chunks) is
471          *   totalChunks - hptSizeChunks
472          * which should be equal to
473          *   nextPhysChunk
474          */
475         return chunk_to_addr(nextPhysChunk);
476 }
477
478 /*
479  * Document me.
480  */
481 static void __init iSeries_setup_arch(void)
482 {
483         if (get_lppaca()->shared_proc) {
484                 ppc_md.idle_loop = iseries_shared_idle;
485                 printk(KERN_DEBUG "Using shared processor idle loop\n");
486         } else {
487                 ppc_md.idle_loop = iseries_dedicated_idle;
488                 printk(KERN_DEBUG "Using dedicated idle loop\n");
489         }
490
491         /* Setup the Lp Event Queue */
492         setup_hvlpevent_queue();
493
494         printk("Max  logical processors = %d\n",
495                         itVpdAreas.xSlicMaxLogicalProcs);
496         printk("Max physical processors = %d\n",
497                         itVpdAreas.xSlicMaxPhysicalProcs);
498
499         iSeries_pcibios_init();
500 }
501
502 static void iSeries_show_cpuinfo(struct seq_file *m)
503 {
504         seq_printf(m, "machine\t\t: 64-bit iSeries Logical Partition\n");
505 }
506
507 static void __init iSeries_progress(char * st, unsigned short code)
508 {
509         printk("Progress: [%04x] - %s\n", (unsigned)code, st);
510         mf_display_progress(code);
511 }
512
513 static void __init iSeries_fixup_klimit(void)
514 {
515         /*
516          * Change klimit to take into account any ram disk
517          * that may be included
518          */
519         if (naca.xRamDisk)
520                 klimit = KERNELBASE + (u64)naca.xRamDisk +
521                         (naca.xRamDiskSize * HW_PAGE_SIZE);
522 }
523
524 static int __init iSeries_src_init(void)
525 {
526         /* clear the progress line */
527         if (firmware_has_feature(FW_FEATURE_ISERIES))
528                 ppc_md.progress(" ", 0xffff);
529         return 0;
530 }
531
532 late_initcall(iSeries_src_init);
533
534 static inline void process_iSeries_events(void)
535 {
536         asm volatile ("li 0,0x5555; sc" : : : "r0", "r3");
537 }
538
539 static void yield_shared_processor(void)
540 {
541         unsigned long tb;
542
543         HvCall_setEnabledInterrupts(HvCall_MaskIPI |
544                                     HvCall_MaskLpEvent |
545                                     HvCall_MaskLpProd |
546                                     HvCall_MaskTimeout);
547
548         tb = get_tb();
549         /* Compute future tb value when yield should expire */
550         HvCall_yieldProcessor(HvCall_YieldTimed, tb+tb_ticks_per_jiffy);
551
552         /*
553          * The decrementer stops during the yield.  Force a fake decrementer
554          * here and let the timer_interrupt code sort out the actual time.
555          */
556         get_lppaca()->int_dword.fields.decr_int = 1;
557         ppc64_runlatch_on();
558         process_iSeries_events();
559 }
560
561 static void iseries_shared_idle(void)
562 {
563         while (1) {
564                 tick_nohz_stop_sched_tick(1);
565                 while (!need_resched() && !hvlpevent_is_pending()) {
566                         local_irq_disable();
567                         ppc64_runlatch_off();
568
569                         /* Recheck with irqs off */
570                         if (!need_resched() && !hvlpevent_is_pending())
571                                 yield_shared_processor();
572
573                         HMT_medium();
574                         local_irq_enable();
575                 }
576
577                 ppc64_runlatch_on();
578                 tick_nohz_restart_sched_tick();
579
580                 if (hvlpevent_is_pending())
581                         process_iSeries_events();
582
583                 preempt_enable_no_resched();
584                 schedule();
585                 preempt_disable();
586         }
587 }
588
589 static void iseries_dedicated_idle(void)
590 {
591         set_thread_flag(TIF_POLLING_NRFLAG);
592
593         while (1) {
594                 tick_nohz_stop_sched_tick(1);
595                 if (!need_resched()) {
596                         while (!need_resched()) {
597                                 ppc64_runlatch_off();
598                                 HMT_low();
599
600                                 if (hvlpevent_is_pending()) {
601                                         HMT_medium();
602                                         ppc64_runlatch_on();
603                                         process_iSeries_events();
604                                 }
605                         }
606
607                         HMT_medium();
608                 }
609
610                 ppc64_runlatch_on();
611                 tick_nohz_restart_sched_tick();
612                 preempt_enable_no_resched();
613                 schedule();
614                 preempt_disable();
615         }
616 }
617
618 static void __iomem *iseries_ioremap(phys_addr_t address, unsigned long size,
619                                      unsigned long flags)
620 {
621         return (void __iomem *)address;
622 }
623
624 static void iseries_iounmap(volatile void __iomem *token)
625 {
626 }
627
628 static int __init iseries_probe(void)
629 {
630         unsigned long root = of_get_flat_dt_root();
631         if (!of_flat_dt_is_compatible(root, "IBM,iSeries"))
632                 return 0;
633
634         hpte_init_iSeries();
635         /* iSeries does not support 16M pages */
636         cur_cpu_spec->cpu_features &= ~CPU_FTR_16M_PAGE;
637
638         return 1;
639 }
640
641 define_machine(iseries) {
642         .name                   = "iSeries",
643         .setup_arch             = iSeries_setup_arch,
644         .show_cpuinfo           = iSeries_show_cpuinfo,
645         .init_IRQ               = iSeries_init_IRQ,
646         .get_irq                = iSeries_get_irq,
647         .init_early             = iSeries_init_early,
648         .pcibios_fixup          = iSeries_pci_final_fixup,
649         .pcibios_fixup_resources= iSeries_pcibios_fixup_resources,
650         .restart                = mf_reboot,
651         .power_off              = mf_power_off,
652         .halt                   = mf_power_off,
653         .get_boot_time          = iSeries_get_boot_time,
654         .set_rtc_time           = iSeries_set_rtc_time,
655         .get_rtc_time           = iSeries_get_rtc_time,
656         .calibrate_decr         = generic_calibrate_decr,
657         .progress               = iSeries_progress,
658         .probe                  = iseries_probe,
659         .ioremap                = iseries_ioremap,
660         .iounmap                = iseries_iounmap,
661         /* XXX Implement enable_pmcs for iSeries */
662 };
663
664 void * __init iSeries_early_setup(void)
665 {
666         unsigned long phys_mem_size;
667
668         /* Identify CPU type. This is done again by the common code later
669          * on but calling this function multiple times is fine.
670          */
671         identify_cpu(0, mfspr(SPRN_PVR));
672
673         powerpc_firmware_features |= FW_FEATURE_ISERIES;
674         powerpc_firmware_features |= FW_FEATURE_LPAR;
675
676         iSeries_fixup_klimit();
677
678         /*
679          * Initialize the table which translate Linux physical addresses to
680          * AS/400 absolute addresses
681          */
682         phys_mem_size = build_iSeries_Memory_Map();
683
684         iSeries_get_cmdline();
685
686         return (void *) __pa(build_flat_dt(phys_mem_size));
687 }
688
689 static void hvputc(char c)
690 {
691         if (c == '\n')
692                 hvputc('\r');
693
694         HvCall_writeLogBuffer(&c, 1);
695 }
696
697 void __init udbg_init_iseries(void)
698 {
699         udbg_putc = hvputc;
700 }