summaryrefslogblamecommitdiff
path: root/arch/powerpc/kernel/head.S
blob: d49bff1a7d51cde337eef16d50fac9077b7c3c61 (plain) (tree)
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537







































































































































                                                                          





                                                             
                      
































































                                                                         
                                














































































































































                                                                               
                                                                    



                                                 
                                                                

































                                                                    
                                                    

































































                                                                      
                                               

                             
                                                                             











                                                                           

                                                                 







                                          

                                                                         

















                                                             
                                             






































































































































































































                                                                              
                                                         

      
                                                                                 
                                                         
                                                                  
                    

                                                                         

                                                              
                                                                         
                                                              
                                                                  
                          






                                                                  
                                                                 














                                                                             










                                                                           
                                                              














                                          
                                              



                                          
                                              





























































































































































































































































































                                                                               
















































                                                                         














































































                                                                        


























































































































































































































































































































































                                                                              
/*
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
 *    Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
 *  Adapted for Power Macintosh by Paul Mackerras.
 *  Low-level exception handlers and MMU support
 *  rewritten by Paul Mackerras.
 *    Copyright (C) 1996 Paul Mackerras.
 *  MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
 *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
 *
 *  This file contains the low-level support and setup for the
 *  PowerPC platform, including trap and interrupt dispatch.
 *  (The PPC 8xx embedded CPUs use head_8xx.S instead.)
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#include <linux/config.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/cputable.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>

#ifdef CONFIG_APUS
#include <asm/amigappc.h>
#endif

#ifdef CONFIG_PPC64BRIDGE
#define LOAD_BAT(n, reg, RA, RB)	\
	ld	RA,(n*32)+0(reg);	\
	ld	RB,(n*32)+8(reg);	\
	mtspr	SPRN_IBAT##n##U,RA;	\
	mtspr	SPRN_IBAT##n##L,RB;	\
	ld	RA,(n*32)+16(reg);	\
	ld	RB,(n*32)+24(reg);	\
	mtspr	SPRN_DBAT##n##U,RA;	\
	mtspr	SPRN_DBAT##n##L,RB;	\

#else /* CONFIG_PPC64BRIDGE */

/* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
#define LOAD_BAT(n, reg, RA, RB)	\
	/* see the comment for clear_bats() -- Cort */ \
	li	RA,0;			\
	mtspr	SPRN_IBAT##n##U,RA;	\
	mtspr	SPRN_DBAT##n##U,RA;	\
	lwz	RA,(n*16)+0(reg);	\
	lwz	RB,(n*16)+4(reg);	\
	mtspr	SPRN_IBAT##n##U,RA;	\
	mtspr	SPRN_IBAT##n##L,RB;	\
	beq	1f;			\
	lwz	RA,(n*16)+8(reg);	\
	lwz	RB,(n*16)+12(reg);	\
	mtspr	SPRN_DBAT##n##U,RA;	\
	mtspr	SPRN_DBAT##n##L,RB;	\
1:
#endif /* CONFIG_PPC64BRIDGE */

	.text
	.stabs	"arch/ppc/kernel/",N_SO,0,0,0f
	.stabs	"head.S",N_SO,0,0,0f
0:
	.globl	_stext
_stext:

/*
 * _start is defined this way because the XCOFF loader in the OpenFirmware
 * on the powermac expects the entry point to be a procedure descriptor.
 */
	.text
	.globl	_start
_start:
	/*
	 * These are here for legacy reasons, the kernel used to
	 * need to look like a coff function entry for the pmac
	 * but we're always started by some kind of bootloader now.
	 *  -- Cort
	 */
	nop	/* used by __secondary_hold on prep (mtx) and chrp smp */
	nop	/* used by __secondary_hold on prep (mtx) and chrp smp */
	nop

/* PMAC
 * Enter here with the kernel text, data and bss loaded starting at
 * 0, running with virtual == physical mapping.
 * r5 points to the prom entry point (the client interface handler
 * address).  Address translation is turned on, with the prom
 * managing the hash table.  Interrupts are disabled.  The stack
 * pointer (r1) points to just below the end of the half-meg region
 * from 0x380000 - 0x400000, which is mapped in already.
 *
 * If we are booted from MacOS via BootX, we enter with the kernel
 * image loaded somewhere, and the following values in registers:
 *  r3: 'BooX' (0x426f6f58)
 *  r4: virtual address of boot_infos_t
 *  r5: 0
 *
 * APUS
 *   r3: 'APUS'
 *   r4: physical address of memory base
 *   Linux/m68k style BootInfo structure at &_end.
 *
 * PREP
 * This is jumped to on prep systems right after the kernel is relocated
 * to its proper place in memory by the boot loader.  The expected layout
 * of the regs is:
 *   r3: ptr to residual data
 *   r4: initrd_start or if no initrd then 0
 *   r5: initrd_end - unused if r4 is 0
 *   r6: Start of command line string
 *   r7: End of command line string
 *
 * This just gets a minimal mmu environment setup so we can call
 * start_here() to do the real work.
 * -- Cort
 */

	.globl	__start
__start:
/*
 * We have to do any OF calls before we map ourselves to KERNELBASE,
 * because OF may have I/O devices mapped into that area
 * (particularly on CHRP).
 */
	cmpwi	0,r5,0
	beq	1f
	bl	prom_init
	trap

1:	mr	r31,r3			/* save parameters */
	mr	r30,r4
	li	r24,0			/* cpu # */

/*
 * early_init() does the early machine identification and does
 * the necessary low-level setup and clears the BSS
 *  -- Cort <cort@fsmlabs.com>
 */
	bl	early_init

/*
 * On POWER4, we first need to tweak some CPU configuration registers
 * like real mode cache inhibit or exception base
 */
#ifdef CONFIG_POWER4
	bl	__970_cpu_preinit
#endif /* CONFIG_POWER4 */

#ifdef CONFIG_APUS
/* On APUS the __va/__pa constants need to be set to the correct
 * values before continuing.
 */
	mr	r4,r30
	bl	fix_mem_constants
#endif /* CONFIG_APUS */

/* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
 * the physical address we are running at, returned by early_init()
 */
 	bl	mmu_off
__after_mmu_off:
#ifndef CONFIG_POWER4
	bl	clear_bats
	bl	flush_tlbs

	bl	initial_bats
#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
	bl	setup_disp_bat
#endif
#else /* CONFIG_POWER4 */
	bl	reloc_offset
	bl	initial_mm_power4
#endif /* CONFIG_POWER4 */

/*
 * Call setup_cpu for CPU 0 and initialize 6xx Idle
 */
	bl	reloc_offset
	li	r24,0			/* cpu# */
	bl	call_setup_cpu		/* Call setup_cpu for this CPU */
#ifdef CONFIG_6xx
	bl	reloc_offset
	bl	init_idle_6xx
#endif /* CONFIG_6xx */
#ifdef CONFIG_POWER4
	bl	reloc_offset
	bl	init_idle_power4
#endif /* CONFIG_POWER4 */


#ifndef CONFIG_APUS
/*
 * We need to run with _start at physical address 0.
 * On CHRP, we are loaded at 0x10000 since OF on CHRP uses
 * the exception vectors at 0 (and therefore this copy
 * overwrites OF's exception vectors with our own).
 * The MMU is off at this point.
 */
	bl	reloc_offset
	mr	r26,r3
	addis	r4,r3,KERNELBASE@h	/* current address of _start */
	cmpwi	0,r4,0			/* are we already running at 0? */
	bne	relocate_kernel
#endif /* CONFIG_APUS */
/*
 * we now have the 1st 16M of ram mapped with the bats.
 * prep needs the mmu to be turned on here, but pmac already has it on.
 * this shouldn't bother the pmac since it just gets turned on again
 * as we jump to our code at KERNELBASE. -- Cort
 * Actually no, pmac doesn't have it on any more. BootX enters with MMU
 * off, and in other cases, we now turn it off before changing BATs above.
 */
turn_on_mmu:
	mfmsr	r0
	ori	r0,r0,MSR_DR|MSR_IR
	mtspr	SPRN_SRR1,r0
	lis	r0,start_here@h
	ori	r0,r0,start_here@l
	mtspr	SPRN_SRR0,r0
	SYNC
	RFI				/* enables MMU */

/*
 * We need __secondary_hold as a place to hold the other cpus on
 * an SMP machine, even when we are running a UP kernel.
 */
	. = 0xc0			/* for prep bootloader */
	li	r3,1			/* MTX only has 1 cpu */
	.globl	__secondary_hold
__secondary_hold:
	/* tell the master we're here */
	stw	r3,4(0)
#ifdef CONFIG_SMP
100:	lwz	r4,0(0)
	/* wait until we're told to start */
	cmpw	0,r4,r3
	bne	100b
	/* our cpu # was at addr 0 - go */
	mr	r24,r3			/* cpu # */
	b	__secondary_start
#else
	b	.
#endif /* CONFIG_SMP */

/*
 * Exception entry code.  This code runs with address translation
 * turned off, i.e. using physical addresses.
 * We assume sprg3 has the physical address of the current
 * task's thread_struct.
 */
#define EXCEPTION_PROLOG	\
	mtspr	SPRN_SPRG0,r10;	\
	mtspr	SPRN_SPRG1,r11;	\
	mfcr	r10;		\
	EXCEPTION_PROLOG_1;	\
	EXCEPTION_PROLOG_2

#define EXCEPTION_PROLOG_1	\
	mfspr	r11,SPRN_SRR1;		/* check whether user or kernel */ \
	andi.	r11,r11,MSR_PR;	\
	tophys(r11,r1);			/* use tophys(r1) if kernel */ \
	beq	1f;		\
	mfspr	r11,SPRN_SPRG3;	\
	lwz	r11,THREAD_INFO-THREAD(r11);	\
	addi	r11,r11,THREAD_SIZE;	\
	tophys(r11,r11);	\
1:	subi	r11,r11,INT_FRAME_SIZE	/* alloc exc. frame */


#define EXCEPTION_PROLOG_2	\
	CLR_TOP32(r11);		\
	stw	r10,_CCR(r11);		/* save registers */ \
	stw	r12,GPR12(r11);	\
	stw	r9,GPR9(r11);	\
	mfspr	r10,SPRN_SPRG0;	\
	stw	r10,GPR10(r11);	\
	mfspr	r12,SPRN_SPRG1;	\
	stw	r12,GPR11(r11);	\
	mflr	r10;		\
	stw	r10,_LINK(r11);	\
	mfspr	r12,SPRN_SRR0;	\
	mfspr	r9,SPRN_SRR1;	\
	stw	r1,GPR1(r11);	\
	stw	r1,0(r11);	\
	tovirt(r1,r11);			/* set new kernel sp */	\
	li	r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
	MTMSRD(r10);			/* (except for mach check in rtas) */ \
	stw	r0,GPR0(r11);	\
	SAVE_4GPRS(3, r11);	\
	SAVE_2GPRS(7, r11)

/*
 * Note: code which follows this uses cr0.eq (set if from kernel),
 * r11, r12 (SRR0), and r9 (SRR1).
 *
 * Note2: once we have set r1 we are in a position to take exceptions
 * again, and we could thus set MSR:RI at that point.
 */

/*
 * Exception vectors.
 */
#define EXCEPTION(n, label, hdlr, xfer)		\
	. = n;					\
label:						\
	EXCEPTION_PROLOG;			\
	addi	r3,r1,STACK_FRAME_OVERHEAD;	\
	xfer(n, hdlr)

#define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret)	\
	li	r10,trap;					\
	stw	r10,TRAP(r11);					\
	li	r10,MSR_KERNEL;					\
	copyee(r10, r9);					\
	bl	tfer;						\
i##n:								\
	.long	hdlr;						\
	.long	ret

#define COPY_EE(d, s)		rlwimi d,s,0,16,16
#define NOCOPY(d, s)

#define EXC_XFER_STD(n, hdlr)		\
	EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full,	\
			  ret_from_except_full)

#define EXC_XFER_LITE(n, hdlr)		\
	EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
			  ret_from_except)

#define EXC_XFER_EE(n, hdlr)		\
	EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
			  ret_from_except_full)

#define EXC_XFER_EE_LITE(n, hdlr)	\
	EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
			  ret_from_except)

/* System reset */
/* core99 pmac starts the seconary here by changing the vector, and
   putting it back to what it was (unknown_exception) when done.  */
#if defined(CONFIG_GEMINI) && defined(CONFIG_SMP)
	. = 0x100
	b	__secondary_start_gemini
#else
	EXCEPTION(0x100, Reset, unknown_exception, EXC_XFER_STD)
#endif

/* Machine check */
/*
 * On CHRP, this is complicated by the fact that we could get a
 * machine check inside RTAS, and we have no guarantee that certain
 * critical registers will have the values we expect.  The set of
 * registers that might have bad values includes all the GPRs
 * and all the BATs.  We indicate that we are in RTAS by putting
 * a non-zero value, the address of the exception frame to use,
 * in SPRG2.  The machine check handler checks SPRG2 and uses its
 * value if it is non-zero.  If we ever needed to free up SPRG2,
 * we could use a field in the thread_info or thread_struct instead.
 * (Other exception handlers assume that r1 is a valid kernel stack
 * pointer when we take an exception from supervisor mode.)
 *	-- paulus.
 */
	. = 0x200
	mtspr	SPRN_SPRG0,r10
	mtspr	SPRN_SPRG1,r11
	mfcr	r10
#ifdef CONFIG_PPC_CHRP
	mfspr	r11,SPRN_SPRG2
	cmpwi	0,r11,0
	bne	7f
#endif /* CONFIG_PPC_CHRP */
	EXCEPTION_PROLOG_1
7:	EXCEPTION_PROLOG_2
	addi	r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_CHRP
	mfspr	r4,SPRN_SPRG2
	cmpwi	cr1,r4,0
	bne	cr1,1f
#endif
	EXC_XFER_STD(0x200, machine_check_exception)
#ifdef CONFIG_PPC_CHRP
1:	b	machine_check_in_rtas
#endif

/* Data access exception. */
	. = 0x300
#ifdef CONFIG_PPC64BRIDGE
	b	DataAccess
DataAccessCont:
#else
DataAccess:
	EXCEPTION_PROLOG
#endif /* CONFIG_PPC64BRIDGE */
	mfspr	r10,SPRN_DSISR
	andis.	r0,r10,0xa470		/* weird error? */
	bne	1f			/* if not, try to put a PTE */
	mfspr	r4,SPRN_DAR		/* into the hash table */
	rlwinm	r3,r10,32-15,21,21	/* DSISR_STORE -> _PAGE_RW */
	bl	hash_page
1:	stw	r10,_DSISR(r11)
	mr	r5,r10
	mfspr	r4,SPRN_DAR
	EXC_XFER_EE_LITE(0x300, handle_page_fault)

#ifdef CONFIG_PPC64BRIDGE
/* SLB fault on data access. */
	. = 0x380
	b	DataSegment
#endif /* CONFIG_PPC64BRIDGE */

/* Instruction access exception. */
	. = 0x400
#ifdef CONFIG_PPC64BRIDGE
	b	InstructionAccess
InstructionAccessCont:
#else
InstructionAccess:
	EXCEPTION_PROLOG
#endif /* CONFIG_PPC64BRIDGE */
	andis.	r0,r9,0x4000		/* no pte found? */
	beq	1f			/* if so, try to put a PTE */
	li	r3,0			/* into the hash table */
	mr	r4,r12			/* SRR0 is fault address */
	bl	hash_page
1:	mr	r4,r12
	mr	r5,r9
	EXC_XFER_EE_LITE(0x400, handle_page_fault)

#ifdef CONFIG_PPC64BRIDGE
/* SLB fault on instruction access. */
	. = 0x480
	b	InstructionSegment
#endif /* CONFIG_PPC64BRIDGE */

/* External interrupt */
	EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)

/* Alignment exception */
	. = 0x600
Alignment:
	EXCEPTION_PROLOG
	mfspr	r4,SPRN_DAR
	stw	r4,_DAR(r11)
	mfspr	r5,SPRN_DSISR
	stw	r5,_DSISR(r11)
	addi	r3,r1,STACK_FRAME_OVERHEAD
	EXC_XFER_EE(0x600, alignment_exception)

/* Program check exception */
	EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)

/* Floating-point unavailable */
	. = 0x800
FPUnavailable:
	EXCEPTION_PROLOG
	bne	load_up_fpu		/* if from user, just load it up */
	addi	r3,r1,STACK_FRAME_OVERHEAD
	EXC_XFER_EE_LITE(0x800, KernelFP)

/* Decrementer */
	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)

	EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)

/* System call */
	. = 0xc00
SystemCall:
	EXCEPTION_PROLOG
	EXC_XFER_EE_LITE(0xc00, DoSyscall)

/* Single step - not used on 601 */
	EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
	EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_EE)

/*
 * The Altivec unavailable trap is at 0x0f20.  Foo.
 * We effectively remap it to 0x3000.
 * We include an altivec unavailable exception vector even if
 * not configured for Altivec, so that you can't panic a
 * non-altivec kernel running on a machine with altivec just
 * by executing an altivec instruction.
 */
	. = 0xf00
	b	Trap_0f

	. = 0xf20
	b	AltiVecUnavailable

Trap_0f:
	EXCEPTION_PROLOG
	addi	r3,r1,STACK_FRAME_OVERHEAD
	EXC_XFER_EE(0xf00, unknown_exception)

/*
 * Handle TLB miss for instruction on 603/603e.
 * Note: we get an alternate set of r0 - r3 to use automatically.
 */
	. = 0x1000
InstructionTLBMiss:
/*
 * r0:	stored ctr
 * r1:	linux style pte ( later becomes ppc hardware pte )
 * r2:	ptr to linux-style pte
 * r3:	scratch
 */
	mfctr	r0
	/* Get PTE (linux-style) and check access */
	mfspr	r3,SPRN_IMISS
	lis	r1,KERNELBASE@h		/* check if kernel address */
	cmplw	0,r3,r1
	mfspr	r2,SPRN_SPRG3
	li	r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
	lwz	r2,PGDIR(r2)
	blt+	112f
	lis	r2,swapper_pg_dir@ha	/* if kernel address, use */
	addi	r2,r2,swapper_pg_dir@l	/* kernel page table */
	mfspr	r1,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
	rlwinm	r1,r1,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
112:	tophys(r2,r2)
	rlwimi	r2,r3,12,20,29		/* insert top 10 bits of address */
	lwz	r2,0(r2)		/* get pmd entry */
	rlwinm.	r2,r2,0,0,19		/* extract address of pte page */
	beq-	InstructionAddressInvalid	/* return if no mapping */
	rlwimi	r2,r3,22,20,29		/* insert next 10 bits of address */
	lwz	r3,0(r2)		/* get linux-style pte */
	andc.	r1,r1,r3		/* check access & ~permission */
	bne-	InstructionAddressInvalid /* return if access not permitted */
	ori	r3,r3,_PAGE_ACCESSED	/* set _PAGE_ACCESSED in pte */
	/*
	 * NOTE! We are assuming this is not an SMP system, otherwise
	 * we would need to update the pte atomically with lwarx/stwcx.
	 */
	stw	r3,0(r2)		/* update PTE (accessed bit) */
	/* Convert linux-style PTE to low word of PPC-style PTE */
	rlwinm	r1,r3,32-10,31,31	/* _PAGE_RW -> PP lsb */
	rlwinm	r2,r3,32-7,31,31	/* _PAGE_DIRTY -> PP lsb */
	and	r1,r1,r2		/* writable if _RW and _DIRTY */
	rlwimi	r3,r3,32-1,30,30	/* _PAGE_USER -> PP msb */
	rlwimi	r3,r3,32-1,31,31	/* _PAGE_USER -> PP lsb */
	ori	r1,r1,0xe14		/* clear out reserved bits and M */
	andc	r1,r3,r1		/* PP = user? (rw&dirty? 2: 3): 0 */
	mtspr	SPRN_RPA,r1
	mfspr	r3,SPRN_IMISS
	tlbli	r3
	mfspr	r3,SPRN_SRR1		/* Need to restore CR0 */
	mtcrf	0x80,r3
	rfi
InstructionAddressInvalid:
	mfspr	r3,SPRN_SRR1
	rlwinm	r1,r3,9,6,6	/* Get load/store bit */

	addis	r1,r1,0x2000
	mtspr	SPRN_DSISR,r1	/* (shouldn't be needed) */
	mtctr	r0		/* Restore CTR */
	andi.	r2,r3,0xFFFF	/* Clear upper bits of SRR1 */
	or	r2,r2,r1
	mtspr	SPRN_SRR1,r2
	mfspr	r1,SPRN_IMISS	/* Get failing address */
	rlwinm.	r2,r2,0,31,31	/* Check for little endian access */
	rlwimi	r2,r2,1,30,30	/* change 1 -> 3 */
	xor	r1,r1,r2
	mtspr	SPRN_DAR,r1	/* Set fault address */
	mfmsr	r0		/* Restore "normal" registers */
	xoris	r0,r0,MSR_TGPR>>16
	mtcrf	0x80,r3		/* Restore CR0 */
	mtmsr	r0
	b	InstructionAccess

/*
 * Handle TLB miss for DATA Load operation on 603/603e
 */
	. = 0x1100
DataLoadTLBMiss:
/*
 * r0:	stored ctr
 * r1:	linux style pte ( later becomes ppc hardware pte )
 * r2:	ptr to linux-style pte
 * r3:	scratch
 */
	mfctr	r0
	/* Get PTE (linux-style) and check access */
	mfspr	r3,SPRN_DMISS
	lis	r1,KERNELBASE@h		/* check if kernel address */
	cmplw	0,r3,r1
	mfspr	r2,SPRN_SPRG3
	li	r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
	lwz	r2,PGDIR(r2)
	blt+	112f
	lis	r2,swapper_pg_dir@ha	/* if kernel address, use */
	addi	r2,r2,swapper_pg_dir@l	/* kernel page table */
	mfspr	r1,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
	rlwinm	r1,r1,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
112:	tophys(r2,r2)
	rlwimi	r2,r3,12,20,29		/* insert top 10 bits of address */
	lwz	r2,0(r2)		/* get pmd entry */
	rlwinm.	r2,r2,0,0,19		/* extract address of pte page */
	beq-	DataAddressInvalid	/* return if no mapping */
	rlwimi	r2,r3,22,20,29		/* insert next 10 bits of address */
	lwz	r3,0(r2)		/* get linux-style pte */
	andc.	r1,r1,r3		/* check access & ~permission */
	bne-	DataAddressInvalid	/* return if access not permitted */
	ori	r3,r3,_PAGE_ACCESSED	/* set _PAGE_ACCESSED in pte */
	/*
	 * NOTE! We are assuming this is not an SMP system, otherwise
	 * we would need to update the pte atomically with lwarx/stwcx.
	 */
	stw	r3,0(r2)		/* update PTE (accessed bit) */
	/* Convert linux-style PTE to low word of PPC-style PTE */
	rlwinm	r1,r3,32-10,31,31	/* _PAGE_RW -> PP lsb */
	rlwinm	r2,r3,32-7,31,31	/* _PAGE_DIRTY -> PP lsb */
	and	r1,r1,r2		/* writable if _RW and _DIRTY */
	rlwimi	r3,r3,32-1,30,30	/* _PAGE_USER -> PP msb */
	rlwimi	r3,r3,32-1,31,31	/* _PAGE_USER -> PP lsb */
	ori	r1,r1,0xe14		/* clear out reserved bits and M */
	andc	r1,r3,r1		/* PP = user? (rw&dirty? 2: 3): 0 */
	mtspr	SPRN_RPA,r1
	mfspr	r3,SPRN_DMISS
	tlbld	r3
	mfspr	r3,SPRN_SRR1		/* Need to restore CR0 */
	mtcrf	0x80,r3
	rfi
DataAddressInvalid:
	mfspr	r3,SPRN_SRR1
	rlwinm	r1,r3,9,6,6	/* Get load/store bit */
	addis	r1,r1,0x2000
	mtspr	SPRN_DSISR,r1
	mtctr	r0		/* Restore CTR */
	andi.	r2,r3,0xFFFF	/* Clear upper bits of SRR1 */
	mtspr	SPRN_SRR1,r2
	mfspr	r1,SPRN_DMISS	/* Get failing address */
	rlwinm.	r2,r2,0,31,31	/* Check for little endian access */
	beq	20f		/* Jump if big endian */
	xori	r1,r1,3
20:	mtspr	SPRN_DAR,r1	/* Set fault address */
	mfmsr	r0		/* Restore "normal" registers */
	xoris	r0,r0,MSR_TGPR>>16
	mtcrf	0x80,r3		/* Restore CR0 */
	mtmsr	r0
	b	DataAccess

/*
 * Handle TLB miss for DATA Store on 603/603e
 */
	. = 0x1200
DataStoreTLBMiss:
/*
 * r0:	stored ctr
 * r1:	linux style pte ( later becomes ppc hardware pte )
 * r2:	ptr to linux-style pte
 * r3:	scratch
 */
	mfctr	r0
	/* Get PTE (linux-style) and check access */
	mfspr	r3,SPRN_DMISS
	lis	r1,KERNELBASE@h		/* check if kernel address */
	cmplw	0,r3,r1
	mfspr	r2,SPRN_SPRG3
	li	r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
	lwz	r2,PGDIR(r2)
	blt+	112f
	lis	r2,swapper_pg_dir@ha	/* if kernel address, use */
	addi	r2,r2,swapper_pg_dir@l	/* kernel page table */
	mfspr	r1,SPRN_SRR1		/* and MSR_PR bit from SRR1 */
	rlwinm	r1,r1,32-12,29,29	/* shift MSR_PR to _PAGE_USER posn */
112:	tophys(r2,r2)
	rlwimi	r2,r3,12,20,29		/* insert top 10 bits of address */
	lwz	r2,0(r2)		/* get pmd entry */
	rlwinm.	r2,r2,0,0,19		/* extract address of pte page */
	beq-	DataAddressInvalid	/* return if no mapping */
	rlwimi	r2,r3,22,20,29		/* insert next 10 bits of address */
	lwz	r3,0(r2)		/* get linux-style pte */
	andc.	r1,r1,r3		/* check access & ~permission */
	bne-	DataAddressInvalid	/* return if access not permitted */
	ori	r3,r3,_PAGE_ACCESSED|_PAGE_DIRTY
	/*
	 * NOTE! We are assuming this is not an SMP system, otherwise
	 * we would need to update the pte atomically with lwarx/stwcx.
	 */
	stw	r3,0(r2)		/* update PTE (accessed/dirty bits) */
	/* Convert linux-style PTE to low word of PPC-style PTE */
	rlwimi	r3,r3,32-1,30,30	/* _PAGE_USER -> PP msb */
	li	r1,0xe15		/* clear out reserved bits and M */
	andc	r1,r3,r1		/* PP = user? 2: 0 */
	mtspr	SPRN_RPA,r1
	mfspr	r3,SPRN_DMISS
	tlbld	r3
	mfspr	r3,SPRN_SRR1		/* Need to restore CR0 */
	mtcrf	0x80,r3
	rfi

#ifndef CONFIG_ALTIVEC
#define altivec_assist_exception	unknown_exception
#endif

	EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_EE)
	EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
	EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
#ifdef CONFIG_POWER4
	EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x1700, Trap_17, altivec_assist_exception, EXC_XFER_EE)
	EXCEPTION(0x1800, Trap_18, TAUException, EXC_XFER_STD)
#else /* !CONFIG_POWER4 */
	EXCEPTION(0x1600, Trap_16, altivec_assist_exception, EXC_XFER_EE)
	EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
	EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
#endif /* CONFIG_POWER4 */
	EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x1c00, Trap_1c, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
	EXCEPTION(0x2100, Trap_21, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2200, Trap_22, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2300, Trap_23, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2400, Trap_24, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2500, Trap_25, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2600, Trap_26, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2700, Trap_27, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2800, Trap_28, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2900, Trap_29, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2a00, Trap_2a, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2b00, Trap_2b, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_EE)
	EXCEPTION(0x2f00, MOLTrampoline, unknown_exception, EXC_XFER_EE_LITE)

	.globl mol_trampoline
	.set mol_trampoline, i0x2f00

	. = 0x3000

AltiVecUnavailable:
	EXCEPTION_PROLOG
#ifdef CONFIG_ALTIVEC
	bne	load_up_altivec		/* if from user, just load it up */
#endif /* CONFIG_ALTIVEC */
	EXC_XFER_EE_LITE(0xf20, altivec_unavailable_exception)

#ifdef CONFIG_PPC64BRIDGE
DataAccess:
	EXCEPTION_PROLOG
	b	DataAccessCont

InstructionAccess:
	EXCEPTION_PROLOG
	b	InstructionAccessCont

DataSegment:
	EXCEPTION_PROLOG
	addi	r3,r1,STACK_FRAME_OVERHEAD
	mfspr	r4,SPRN_DAR
	stw	r4,_DAR(r11)
	EXC_XFER_STD(0x380, unknown_exception)

InstructionSegment:
	EXCEPTION_PROLOG
	addi	r3,r1,STACK_FRAME_OVERHEAD
	EXC_XFER_STD(0x480, unknown_exception)
#endif /* CONFIG_PPC64BRIDGE */

#ifdef CONFIG_ALTIVEC
/* Note that the AltiVec support is closely modeled after the FP
 * support.  Changes to one are likely to be applicable to the
 * other!  */
load_up_altivec:
/*
 * Disable AltiVec for the task which had AltiVec previously,
 * and save its AltiVec registers in its thread_struct.
 * Enables AltiVec for use in the kernel on return.
 * On SMP we know the AltiVec units are free, since we give it up every
 * switch.  -- Kumar
 */
	mfmsr	r5
	oris	r5,r5,MSR_VEC@h
	MTMSRD(r5)			/* enable use of AltiVec now */
	isync
/*
 * For SMP, we don't do lazy AltiVec switching because it just gets too
 * horrendously complex, especially when a task switches from one CPU
 * to another.  Instead we call giveup_altivec in switch_to.
 */
#ifndef CONFIG_SMP
	tophys(r6,0)
	addis	r3,r6,last_task_used_altivec@ha
	lwz	r4,last_task_used_altivec@l(r3)
	cmpwi	0,r4,0
	beq	1f
	add	r4,r4,r6
	addi	r4,r4,THREAD	/* want THREAD of last_task_used_altivec */
	SAVE_32VRS(0,r10,r4)
	mfvscr	vr0
	li	r10,THREAD_VSCR
	stvx	vr0,r10,r4
	lwz	r5,PT_REGS(r4)
	add	r5,r5,r6
	lwz	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
	lis	r10,MSR_VEC@h
	andc	r4,r4,r10	/* disable altivec for previous task */
	stw	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
1:
#endif /* CONFIG_SMP */
	/* enable use of AltiVec after return */
	oris	r9,r9,MSR_VEC@h
	mfspr	r5,SPRN_SPRG3		/* current task's THREAD (phys) */
	li	r4,1
	li	r10,THREAD_VSCR
	stw	r4,THREAD_USED_VR(r5)
	lvx	vr0,r10,r5
	mtvscr	vr0
	REST_32VRS(0,r10,r5)
#ifndef CONFIG_SMP
	subi	r4,r5,THREAD
	sub	r4,r4,r6
	stw	r4,last_task_used_altivec@l(r3)
#endif /* CONFIG_SMP */
	/* restore registers and return */
	/* we haven't used ctr or xer or lr */
	b	fast_exception_return

/*
 * AltiVec unavailable trap from kernel - print a message, but let
 * the task use AltiVec in the kernel until it returns to user mode.
 */
KernelAltiVec:
	lwz	r3,_MSR(r1)
	oris	r3,r3,MSR_VEC@h
	stw	r3,_MSR(r1)	/* enable use of AltiVec after return */
	lis	r3,87f@h
	ori	r3,r3,87f@l
	mr	r4,r2		/* current */
	lwz	r5,_NIP(r1)
	bl	printk
	b	ret_from_except
87:	.string	"AltiVec used in kernel  (task=%p, pc=%x)  \n"
	.align	4,0

/*
 * giveup_altivec(tsk)
 * Disable AltiVec for the task given as the argument,
 * and save the AltiVec registers in its thread_struct.
 * Enables AltiVec for use in the kernel on return.
 */

	.globl	giveup_altivec
giveup_altivec:
	mfmsr	r5
	oris	r5,r5,MSR_VEC@h
	SYNC
	MTMSRD(r5)			/* enable use of AltiVec now */
	isync
	cmpwi	0,r3,0
	beqlr-				/* if no previous owner, done */
	addi	r3,r3,THREAD		/* want THREAD of task */
	lwz	r5,PT_REGS(r3)
	cmpwi	0,r5,0
	SAVE_32VRS(0, r4, r3)
	mfvscr	vr0
	li	r4,THREAD_VSCR
	stvx	vr0,r4,r3
	beq	1f
	lwz	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
	lis	r3,MSR_VEC@h
	andc	r4,r4,r3		/* disable AltiVec for previous task */
	stw	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
1:
#ifndef CONFIG_SMP
	li	r5,0
	lis	r4,last_task_used_altivec@ha
	stw	r5,last_task_used_altivec@l(r4)
#endif /* CONFIG_SMP */
	blr
#endif /* CONFIG_ALTIVEC */

/*
 * This code is jumped to from the startup code to copy
 * the kernel image to physical address 0.
 */
relocate_kernel:
	addis	r9,r26,klimit@ha	/* fetch klimit */
	lwz	r25,klimit@l(r9)
	addis	r25,r25,-KERNELBASE@h
	li	r3,0			/* Destination base address */
	li	r6,0			/* Destination offset */
	li	r5,0x4000		/* # bytes of memory to copy */
	bl	copy_and_flush		/* copy the first 0x4000 bytes */
	addi	r0,r3,4f@l		/* jump to the address of 4f */
	mtctr	r0			/* in copy and do the rest. */
	bctr				/* jump to the copy */
4:	mr	r5,r25
	bl	copy_and_flush		/* copy the rest */
	b	turn_on_mmu

/*
 * Copy routine used to copy the kernel to start at physical address 0
 * and flush and invalidate the caches as needed.
 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
 */
copy_and_flush:
	addi	r5,r5,-4
	addi	r6,r6,-4
4:	li	r0,L1_CACHE_LINE_SIZE/4
	mtctr	r0
3:	addi	r6,r6,4			/* copy a cache line */
	lwzx	r0,r6,r4
	stwx	r0,r6,r3
	bdnz	3b
	dcbst	r6,r3			/* write it to memory */
	sync
	icbi	r6,r3			/* flush the icache line */
	cmplw	0,r6,r5
	blt	4b
	sync				/* additional sync needed on g4 */
	isync
	addi	r5,r5,4
	addi	r6,r6,4
	blr

#ifdef CONFIG_APUS
/*
 * On APUS the physical base address of the kernel is not known at compile
 * time, which means the __pa/__va constants used are incorrect. In the
 * __init section is recorded the virtual addresses of instructions using
 * these constants, so all that has to be done is fix these before
 * continuing the kernel boot.
 *
 * r4 = The physical address of the kernel base.
 */
fix_mem_constants:
	mr	r10,r4
	addis	r10,r10,-KERNELBASE@h    /* virt_to_phys constant */
	neg	r11,r10	                 /* phys_to_virt constant */

	lis	r12,__vtop_table_begin@h
	ori	r12,r12,__vtop_table_begin@l
	add	r12,r12,r10	         /* table begin phys address */
	lis	r13,__vtop_table_end@h
	ori	r13,r13,__vtop_table_end@l
	add	r13,r13,r10	         /* table end phys address */
	subi	r12,r12,4
	subi	r13,r13,4
1:	lwzu	r14,4(r12)               /* virt address of instruction */
	add     r14,r14,r10              /* phys address of instruction */
	lwz     r15,0(r14)               /* instruction, now insert top */
	rlwimi  r15,r10,16,16,31         /* half of vp const in low half */
	stw	r15,0(r14)               /* of instruction and restore. */
	dcbst	r0,r14			 /* write it to memory */
	sync
	icbi	r0,r14			 /* flush the icache line */
	cmpw	r12,r13
	bne     1b
	sync				/* additional sync needed on g4 */
	isync

/*
 * Map the memory where the exception handlers will
 * be copied to when hash constants have been patched.
 */
#ifdef CONFIG_APUS_FAST_EXCEPT
	lis	r8,0xfff0
#else
	lis	r8,0
#endif
	ori	r8,r8,0x2		/* 128KB, supervisor */
	mtspr	SPRN_DBAT3U,r8
	mtspr	SPRN_DBAT3L,r8

	lis	r12,__ptov_table_begin@h
	ori	r12,r12,__ptov_table_begin@l
	add	r12,r12,r10	         /* table begin phys address */
	lis	r13,__ptov_table_end@h
	ori	r13,r13,__ptov_table_end@l
	add	r13,r13,r10	         /* table end phys address */
	subi	r12,r12,4
	subi	r13,r13,4
1:	lwzu	r14,4(r12)               /* virt address of instruction */
	add     r14,r14,r10              /* phys address of instruction */
	lwz     r15,0(r14)               /* instruction, now insert top */
	rlwimi  r15,r11,16,16,31         /* half of pv const in low half*/
	stw	r15,0(r14)               /* of instruction and restore. */
	dcbst	r0,r14			 /* write it to memory */
	sync
	icbi	r0,r14			 /* flush the icache line */
	cmpw	r12,r13
	bne     1b

	sync				/* additional sync needed on g4 */
	isync				/* No speculative loading until now */
	blr

/***********************************************************************
 *  Please note that on APUS the exception handlers are located at the
 *  physical address 0xfff0000. For this reason, the exception handlers
 *  cannot use relative branches to access the code below.
 ***********************************************************************/
#endif /* CONFIG_APUS */

#ifdef CONFIG_SMP
#ifdef CONFIG_GEMINI
	.globl	__secondary_start_gemini
__secondary_start_gemini:
        mfspr   r4,SPRN_HID0
        ori     r4,r4,HID0_ICFI
        li      r3,0
        ori     r3,r3,HID0_ICE
        andc    r4,r4,r3
        mtspr   SPRN_HID0,r4
        sync
        b       __secondary_start
#endif /* CONFIG_GEMINI */

	.globl	__secondary_start_pmac_0
__secondary_start_pmac_0:
	/* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
	li	r24,0
	b	1f
	li	r24,1
	b	1f
	li	r24,2
	b	1f
	li	r24,3
1:
	/* on powersurge, we come in here with IR=0 and DR=1, and DBAT 0
	   set to map the 0xf0000000 - 0xffffffff region */
	mfmsr	r0
	rlwinm	r0,r0,0,28,26		/* clear DR (0x10) */
	SYNC
	mtmsr	r0
	isync

	.globl	__secondary_start
__secondary_start:
#ifdef CONFIG_PPC64BRIDGE
	mfmsr	r0
	clrldi	r0,r0,1			/* make sure it's in 32-bit mode */
	SYNC
	MTMSRD(r0)
	isync
#endif
	/* Copy some CPU settings from CPU 0 */
	bl	__restore_cpu_setup

	lis	r3,-KERNELBASE@h
	mr	r4,r24
	bl	call_setup_cpu		/* Call setup_cpu for this CPU */
#ifdef CONFIG_6xx
	lis	r3,-KERNELBASE@h
	bl	init_idle_6xx
#endif /* CONFIG_6xx */
#ifdef CONFIG_POWER4
	lis	r3,-KERNELBASE@h
	bl	init_idle_power4
#endif /* CONFIG_POWER4 */

	/* get current_thread_info and current */
	lis	r1,secondary_ti@ha
	tophys(r1,r1)
	lwz	r1,secondary_ti@l(r1)
	tophys(r2,r1)
	lwz	r2,TI_TASK(r2)

	/* stack */
	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
	li	r0,0
	tophys(r3,r1)
	stw	r0,0(r3)

	/* load up the MMU */
	bl	load_up_mmu

	/* ptr to phys current thread */
	tophys(r4,r2)
	addi	r4,r4,THREAD	/* phys address of our thread_struct */
	CLR_TOP32(r4)
	mtspr	SPRN_SPRG3,r4
	li	r3,0
	mtspr	SPRN_SPRG2,r3	/* 0 => not in RTAS */

	/* enable MMU and jump to start_secondary */
	li	r4,MSR_KERNEL
	FIX_SRR1(r4,r5)
	lis	r3,start_secondary@h
	ori	r3,r3,start_secondary@l
	mtspr	SPRN_SRR0,r3
	mtspr	SPRN_SRR1,r4
	SYNC
	RFI
#endif /* CONFIG_SMP */

/*
 * Those generic dummy functions are kept for CPUs not
 * included in CONFIG_6xx
 */
#if !defined(CONFIG_6xx) && !defined(CONFIG_POWER4)
_GLOBAL(__save_cpu_setup)
	blr
_GLOBAL(__restore_cpu_setup)
	blr
#endif /* !defined(CONFIG_6xx) && !defined(CONFIG_POWER4) */


/*
 * Load stuff into the MMU.  Intended to be called with
 * IR=0 and DR=0.
 */
load_up_mmu:
	sync			/* Force all PTE updates to finish */
	isync
	tlbia			/* Clear all TLB entries */
	sync			/* wait for tlbia/tlbie to finish */
	TLBSYNC			/* ... on all CPUs */
	/* Load the SDR1 register (hash table base & size) */
	lis	r6,_SDR1@ha
	tophys(r6,r6)
	lwz	r6,_SDR1@l(r6)
	mtspr	SPRN_SDR1,r6
#ifdef CONFIG_PPC64BRIDGE
	/* clear the ASR so we only use the pseudo-segment registers. */
	li	r6,0
	mtasr	r6
#endif /* CONFIG_PPC64BRIDGE */
	li	r0,16		/* load up segment register values */
	mtctr	r0		/* for context 0 */
	lis	r3,0x2000	/* Ku = 1, VSID = 0 */
	li	r4,0
3:	mtsrin	r3,r4
	addi	r3,r3,0x111	/* increment VSID */
	addis	r4,r4,0x1000	/* address of next segment */
	bdnz	3b
#ifndef CONFIG_POWER4
/* Load the BAT registers with the values set up by MMU_init.
   MMU_init takes care of whether we're on a 601 or not. */
	mfpvr	r3
	srwi	r3,r3,16
	cmpwi	r3,1
	lis	r3,BATS@ha
	addi	r3,r3,BATS@l
	tophys(r3,r3)
	LOAD_BAT(0,r3,r4,r5)
	LOAD_BAT(1,r3,r4,r5)
	LOAD_BAT(2,r3,r4,r5)
	LOAD_BAT(3,r3,r4,r5)
#endif /* CONFIG_POWER4 */
	blr

/*
 * This is where the main kernel code starts.
 */
start_here:
	/* ptr to current */
	lis	r2,init_task@h
	ori	r2,r2,init_task@l
	/* Set up for using our exception vectors */
	/* ptr to phys current thread */
	tophys(r4,r2)
	addi	r4,r4,THREAD	/* init task's THREAD */
	CLR_TOP32(r4)
	mtspr	SPRN_SPRG3,r4
	li	r3,0
	mtspr	SPRN_SPRG2,r3	/* 0 => not in RTAS */

	/* stack */
	lis	r1,init_thread_union@ha
	addi	r1,r1,init_thread_union@l
	li	r0,0
	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
/*
 * Do early bootinfo parsing, platform-specific initialization,
 * and set up the MMU.
 */
	mr	r3,r31
	mr	r4,r30
	bl	machine_init
	bl	MMU_init

#ifdef CONFIG_APUS
	/* Copy exception code to exception vector base on APUS. */
	lis	r4,KERNELBASE@h
#ifdef CONFIG_APUS_FAST_EXCEPT
	lis	r3,0xfff0		/* Copy to 0xfff00000 */
#else
	lis	r3,0			/* Copy to 0x00000000 */
#endif
	li	r5,0x4000		/* # bytes of memory to copy */
	li	r6,0
	bl	copy_and_flush		/* copy the first 0x4000 bytes */
#endif  /* CONFIG_APUS */

/*
 * Go back to running unmapped so we can load up new values
 * for SDR1 (hash table pointer) and the segment registers
 * and change to using our exception vectors.
 */
	lis	r4,2f@h
	ori	r4,r4,2f@l
	tophys(r4,r4)
	li	r3,MSR_KERNEL & ~(MSR_IR|MSR_DR)
	FIX_SRR1(r3,r5)
	mtspr	SPRN_SRR0,r4
	mtspr	SPRN_SRR1,r3
	SYNC
	RFI
/* Load up the kernel context */
2:	bl	load_up_mmu

#ifdef CONFIG_BDI_SWITCH
	/* Add helper information for the Abatron bdiGDB debugger.
	 * We do this here because we know the mmu is disabled, and
	 * will be enabled for real in just a few instructions.
	 */
	lis	r5, abatron_pteptrs@h
	ori	r5, r5, abatron_pteptrs@l
	stw	r5, 0xf0(r0)	/* This much match your Abatron config */
	lis	r6, swapper_pg_dir@h
	ori	r6, r6, swapper_pg_dir@l
	tophys(r5, r5)
	stw	r6, 0(r5)
#endif /* CONFIG_BDI_SWITCH */

/* Now turn on the MMU for real! */
	li	r4,MSR_KERNEL
	FIX_SRR1(r4,r5)
	lis	r3,start_kernel@h
	ori	r3,r3,start_kernel@l
	mtspr	SPRN_SRR0,r3
	mtspr	SPRN_SRR1,r4
	SYNC
	RFI

/*
 * Set up the segment registers for a new context.
 */
_GLOBAL(set_context)
	mulli	r3,r3,897	/* multiply context by skew factor */
	rlwinm	r3,r3,4,8,27	/* VSID = (context & 0xfffff) << 4 */
	addis	r3,r3,0x6000	/* Set Ks, Ku bits */
	li	r0,NUM_USER_SEGMENTS
	mtctr	r0

#ifdef CONFIG_BDI_SWITCH
	/* Context switch the PTE pointer for the Abatron BDI2000.
	 * The PGDIR is passed as second argument.
	 */
	lis	r5, KERNELBASE@h
	lwz	r5, 0xf0(r5)
	stw	r4, 0x4(r5)
#endif
	li	r4,0
	isync
3:
#ifdef CONFIG_PPC64BRIDGE
	slbie	r4
#endif /* CONFIG_PPC64BRIDGE */
	mtsrin	r3,r4
	addi	r3,r3,0x111	/* next VSID */
	rlwinm	r3,r3,0,8,3	/* clear out any overflow from VSID field */
	addis	r4,r4,0x1000	/* address of next segment */
	bdnz	3b
	sync
	isync
	blr

/*
 * An undocumented "feature" of 604e requires that the v bit
 * be cleared before changing BAT values.
 *
 * Also, newer IBM firmware does not clear bat3 and 4 so
 * this makes sure it's done.
 *  -- Cort
 */
clear_bats:
	li	r10,0
	mfspr	r9,SPRN_PVR
	rlwinm	r9,r9,16,16,31		/* r9 = 1 for 601, 4 for 604 */
	cmpwi	r9, 1
	beq	1f

	mtspr	SPRN_DBAT0U,r10
	mtspr	SPRN_DBAT0L,r10
	mtspr	SPRN_DBAT1U,r10
	mtspr	SPRN_DBAT1L,r10
	mtspr	SPRN_DBAT2U,r10
	mtspr	SPRN_DBAT2L,r10
	mtspr	SPRN_DBAT3U,r10
	mtspr	SPRN_DBAT3L,r10
1:
	mtspr	SPRN_IBAT0U,r10
	mtspr	SPRN_IBAT0L,r10
	mtspr	SPRN_IBAT1U,r10
	mtspr	SPRN_IBAT1L,r10
	mtspr	SPRN_IBAT2U,r10
	mtspr	SPRN_IBAT2L,r10
	mtspr	SPRN_IBAT3U,r10
	mtspr	SPRN_IBAT3L,r10
BEGIN_FTR_SECTION
	/* Here's a tweak: at this point, CPU setup have
	 * not been called yet, so HIGH_BAT_EN may not be
	 * set in HID0 for the 745x processors. However, it
	 * seems that doesn't affect our ability to actually
	 * write to these SPRs.
	 */
	mtspr	SPRN_DBAT4U,r10
	mtspr	SPRN_DBAT4L,r10
	mtspr	SPRN_DBAT5U,r10
	mtspr	SPRN_DBAT5L,r10
	mtspr	SPRN_DBAT6U,r10
	mtspr	SPRN_DBAT6L,r10
	mtspr	SPRN_DBAT7U,r10
	mtspr	SPRN_DBAT7L,r10
	mtspr	SPRN_IBAT4U,r10
	mtspr	SPRN_IBAT4L,r10
	mtspr	SPRN_IBAT5U,r10
	mtspr	SPRN_IBAT5L,r10
	mtspr	SPRN_IBAT6U,r10
	mtspr	SPRN_IBAT6L,r10
	mtspr	SPRN_IBAT7U,r10
	mtspr	SPRN_IBAT7L,r10
END_FTR_SECTION_IFSET(CPU_FTR_HAS_HIGH_BATS)
	blr

flush_tlbs:
	lis	r10, 0x40
1:	addic.	r10, r10, -0x1000
	tlbie	r10
	blt	1b
	sync
	blr

mmu_off:
 	addi	r4, r3, __after_mmu_off - _start
	mfmsr	r3
	andi.	r0,r3,MSR_DR|MSR_IR		/* MMU enabled? */
	beqlr
	andc	r3,r3,r0
	mtspr	SPRN_SRR0,r4
	mtspr	SPRN_SRR1,r3
	sync
	RFI

#ifndef CONFIG_POWER4
/*
 * Use the first pair of BAT registers to map the 1st 16MB
 * of RAM to KERNELBASE.  From this point on we can't safely
 * call OF any more.
 */
initial_bats:
	lis	r11,KERNELBASE@h
#ifndef CONFIG_PPC64BRIDGE
	mfspr	r9,SPRN_PVR
	rlwinm	r9,r9,16,16,31		/* r9 = 1 for 601, 4 for 604 */
	cmpwi	0,r9,1
	bne	4f
	ori	r11,r11,4		/* set up BAT registers for 601 */
	li	r8,0x7f			/* valid, block length = 8MB */
	oris	r9,r11,0x800000@h	/* set up BAT reg for 2nd 8M */
	oris	r10,r8,0x800000@h	/* set up BAT reg for 2nd 8M */
	mtspr	SPRN_IBAT0U,r11		/* N.B. 601 has valid bit in */
	mtspr	SPRN_IBAT0L,r8		/* lower BAT register */
	mtspr	SPRN_IBAT1U,r9
	mtspr	SPRN_IBAT1L,r10
	isync
	blr
#endif /* CONFIG_PPC64BRIDGE */

4:	tophys(r8,r11)
#ifdef CONFIG_SMP
	ori	r8,r8,0x12		/* R/W access, M=1 */
#else
	ori	r8,r8,2			/* R/W access */
#endif /* CONFIG_SMP */
#ifdef CONFIG_APUS
	ori	r11,r11,BL_8M<<2|0x2	/* set up 8MB BAT registers for 604 */
#else
	ori	r11,r11,BL_256M<<2|0x2	/* set up BAT registers for 604 */
#endif /* CONFIG_APUS */

#ifdef CONFIG_PPC64BRIDGE
	/* clear out the high 32 bits in the BAT */
	clrldi	r11,r11,32
	clrldi	r8,r8,32
#endif /* CONFIG_PPC64BRIDGE */
	mtspr	SPRN_DBAT0L,r8		/* N.B. 6xx (not 601) have valid */
	mtspr	SPRN_DBAT0U,r11		/* bit in upper BAT register */
	mtspr	SPRN_IBAT0L,r8
	mtspr	SPRN_IBAT0U,r11
	isync
	blr

#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
setup_disp_bat:
	/*
	 * setup the display bat prepared for us in prom.c
	 */
	mflr	r8
	bl	reloc_offset
	mtlr	r8
	addis	r8,r3,disp_BAT@ha
	addi	r8,r8,disp_BAT@l
	lwz	r11,0(r8)
	lwz	r8,4(r8)
	mfspr	r9,SPRN_PVR
	rlwinm	r9,r9,16,16,31		/* r9 = 1 for 601, 4 for 604 */
	cmpwi	0,r9,1
	beq	1f
	mtspr	SPRN_DBAT3L,r8
	mtspr	SPRN_DBAT3U,r11
	blr
1:	mtspr	SPRN_IBAT3L,r8
	mtspr	SPRN_IBAT3U,r11
	blr

#endif /* !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT) */

#else /* CONFIG_POWER4 */
/*
 * Load up the SDR1 and segment register values now
 * since we don't have the BATs.
 * Also make sure we are running in 32-bit mode.
 */

initial_mm_power4:
	addis	r14,r3,_SDR1@ha		/* get the value from _SDR1 */
	lwz	r14,_SDR1@l(r14)	/* assume hash table below 4GB */
	mtspr	SPRN_SDR1,r14
	slbia
	lis	r4,0x2000		/* set pseudo-segment reg 12 */
	ori	r5,r4,0x0ccc
	mtsr	12,r5
#if 0
	ori	r5,r4,0x0888		/* set pseudo-segment reg 8 */
	mtsr	8,r5			/* (for access to serial port) */
#endif
#ifdef CONFIG_BOOTX_TEXT
	ori	r5,r4,0x0999		/* set pseudo-segment reg 9 */
	mtsr	9,r5			/* (for access to screen) */
#endif
	mfmsr	r0
	clrldi	r0,r0,1
	sync
	mtmsr	r0
	isync
	blr

#endif /* CONFIG_POWER4 */

#ifdef CONFIG_8260
/* Jump into the system reset for the rom.
 * We first disable the MMU, and then jump to the ROM reset address.
 *
 * r3 is the board info structure, r4 is the location for starting.
 * I use this for building a small kernel that can load other kernels,
 * rather than trying to write or rely on a rom monitor that can tftp load.
 */
       .globl  m8260_gorom
m8260_gorom:
	mfmsr	r0
	rlwinm	r0,r0,0,17,15	/* clear MSR_EE in r0 */
	sync
	mtmsr	r0
	sync
	mfspr	r11, SPRN_HID0
	lis	r10, 0
	ori	r10,r10,HID0_ICE|HID0_DCE
	andc	r11, r11, r10
	mtspr	SPRN_HID0, r11
	isync
	li	r5, MSR_ME|MSR_RI
	lis	r6,2f@h
	addis	r6,r6,-KERNELBASE@h
	ori	r6,r6,2f@l
	mtspr	SPRN_SRR0,r6
	mtspr	SPRN_SRR1,r5
	isync
	sync
	rfi
2:
	mtlr	r4
	blr
#endif


/*
 * We put a few things here that have to be page-aligned.
 * This stuff goes at the beginning of the data segment,
 * which is page-aligned.
 */
	.data
	.globl	sdata
sdata:
	.globl	empty_zero_page
empty_zero_page:
	.space	4096

	.globl	swapper_pg_dir
swapper_pg_dir:
	.space	4096

/*
 * This space gets a copy of optional info passed to us by the bootstrap
 * Used to pass parameters into the kernel like root=/dev/sda1, etc.
 */
	.globl	cmd_line
cmd_line:
	.space	512

	.globl intercept_table
intercept_table:
	.long 0, 0, i0x200, i0x300, i0x400, 0, i0x600, i0x700
	.long i0x800, 0, 0, 0, 0, i0xd00, 0, 0
	.long 0, 0, 0, i0x1300, 0, 0, 0, 0
	.long 0, 0, 0, 0, 0, 0, 0, 0
	.long 0, 0, 0, 0, 0, 0, 0, 0
	.long 0, 0, 0, 0, 0, 0, 0, 0

/* Room for two PTE pointers, usually the kernel and current user pointers
 * to their respective root page table.
 */
abatron_pteptrs:
	.space	8