| blob | 377e0c155c95a5a904c3394451266bd8d0fede0d |
1 /*
2 * Kernel execution entry point code.
3 *
4 * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org>
5 * Initial PowerPC version.
6 * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu>
7 * Rewritten for PReP
8 * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
9 * Low-level exception handers, MMU support, and rewrite.
10 * Copyright (c) 1997 Dan Malek <dmalek@jlc.net>
11 * PowerPC 8xx modifications.
12 * Copyright (c) 1998-1999 TiVo, Inc.
13 * PowerPC 403GCX modifications.
14 * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
15 * PowerPC 403GCX/405GP modifications.
16 * Copyright 2000 MontaVista Software Inc.
17 * PPC405 modifications
18 * PowerPC 403GCX/405GP modifications.
19 * Author: MontaVista Software, Inc.
20 * frank_rowand@mvista.com or source@mvista.com
21 * debbie_chu@mvista.com
22 * Copyright 2002-2004 MontaVista Software, Inc.
23 * PowerPC 44x support, Matt Porter <mporter@kernel.crashing.org>
24 * Copyright 2004 Freescale Semiconductor, Inc
25 * PowerPC e500 modifications, Kumar Gala <galak@kernel.crashing.org>
26 *
27 * This program is free software; you can redistribute it and/or modify it
28 * under the terms of the GNU General Public License as published by the
29 * Free Software Foundation; either version 2 of the License, or (at your
30 * option) any later version.
31 */
33 #include <linux/threads.h>
34 #include <asm/processor.h>
35 #include <asm/page.h>
36 #include <asm/mmu.h>
37 #include <asm/pgtable.h>
38 #include <asm/cputable.h>
39 #include <asm/thread_info.h>
40 #include <asm/ppc_asm.h>
41 #include <asm/asm-offsets.h>
42 #include <asm/cache.h>
43 #include "head_booke.h"
45 /* As with the other PowerPC ports, it is expected that when code
46 * execution begins here, the following registers contain valid, yet
47 * optional, information:
48 *
49 * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.)
50 * r4 - Starting address of the init RAM disk
51 * r5 - Ending address of the init RAM disk
52 * r6 - Start of kernel command line string (e.g. "mem=128")
53 * r7 - End of kernel command line string
54 *
55 */
56 .section .text.head, "ax"
57 _ENTRY(_stext);
58 _ENTRY(_start);
59 /*
60 * Reserve a word at a fixed location to store the address
61 * of abatron_pteptrs
62 */
63 nop
64 /*
65 * Save parameters we are passed
66 */
67 mr r31,r3
68 mr r30,r4
69 mr r29,r5
70 mr r28,r6
71 mr r27,r7
72 li r25,0 /* phys kernel start (low) */
73 li r24,0 /* CPU number */
74 li r23,0 /* phys kernel start (high) */
76 /* We try to not make any assumptions about how the boot loader
77 * setup or used the TLBs. We invalidate all mappings from the
78 * boot loader and load a single entry in TLB1[0] to map the
79 * first 64M of kernel memory. Any boot info passed from the
80 * bootloader needs to live in this first 64M.
81 *
82 * Requirement on bootloader:
83 * - The page we're executing in needs to reside in TLB1 and
84 * have IPROT=1. If not an invalidate broadcast could
85 * evict the entry we're currently executing in.
86 *
87 * r3 = Index of TLB1 were executing in
88 * r4 = Current MSR[IS]
89 * r5 = Index of TLB1 temp mapping
90 *
91 * Later in mapin_ram we will correctly map lowmem, and resize TLB1[0]
92 * if needed
93 */
95 /* 1. Find the index of the entry we're executing in */
96 bl invstr /* Find our address */
97 invstr: mflr r6 /* Make it accessible */
98 mfmsr r7
99 rlwinm r4,r7,27,31,31 /* extract MSR[IS] */
100 mfspr r7, SPRN_PID0
101 slwi r7,r7,16
102 or r7,r7,r4
103 mtspr SPRN_MAS6,r7
104 tlbsx 0,r6 /* search MSR[IS], SPID=PID0 */
105 #ifndef CONFIG_E200
106 mfspr r7,SPRN_MAS1
107 andis. r7,r7,MAS1_VALID@h
108 bne match_TLB
109 mfspr r7,SPRN_PID1
110 slwi r7,r7,16
111 or r7,r7,r4
112 mtspr SPRN_MAS6,r7
113 tlbsx 0,r6 /* search MSR[IS], SPID=PID1 */
114 mfspr r7,SPRN_MAS1
115 andis. r7,r7,MAS1_VALID@h
116 bne match_TLB
117 mfspr r7, SPRN_PID2
118 slwi r7,r7,16
119 or r7,r7,r4
120 mtspr SPRN_MAS6,r7
121 tlbsx 0,r6 /* Fall through, we had to match */
122 #endif
123 match_TLB:
124 mfspr r7,SPRN_MAS0
125 rlwinm r3,r7,16,20,31 /* Extract MAS0(Entry) */
127 mfspr r7,SPRN_MAS1 /* Insure IPROT set */
128 oris r7,r7,MAS1_IPROT@h
129 mtspr SPRN_MAS1,r7
130 tlbwe
132 /* 2. Invalidate all entries except the entry we're executing in */
133 mfspr r9,SPRN_TLB1CFG
134 andi. r9,r9,0xfff
135 li r6,0 /* Set Entry counter to 0 */
136 1: lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
137 rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */
138 mtspr SPRN_MAS0,r7
139 tlbre
140 mfspr r7,SPRN_MAS1
141 rlwinm r7,r7,0,2,31 /* Clear MAS1 Valid and IPROT */
142 cmpw r3,r6
143 beq skpinv /* Dont update the current execution TLB */
144 mtspr SPRN_MAS1,r7
145 tlbwe
146 isync
147 skpinv: addi r6,r6,1 /* Increment */
148 cmpw r6,r9 /* Are we done? */
149 bne 1b /* If not, repeat */
151 /* Invalidate TLB0 */
152 li r6,0x04
153 tlbivax 0,r6
154 TLBSYNC
155 /* Invalidate TLB1 */
156 li r6,0x0c
157 tlbivax 0,r6
158 TLBSYNC
160 /* 3. Setup a temp mapping and jump to it */
161 andi. r5, r3, 0x1 /* Find an entry not used and is non-zero */
162 addi r5, r5, 0x1
163 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
164 rlwimi r7,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */
165 mtspr SPRN_MAS0,r7
166 tlbre
168 /* grab and fixup the RPN */
169 mfspr r6,SPRN_MAS1 /* extract MAS1[SIZE] */
170 rlwinm r6,r6,25,27,30
171 li r8,-1
172 addi r6,r6,10
173 slw r6,r8,r6 /* convert to mask */
175 bl 1f /* Find our address */
176 1: mflr r7
178 mfspr r8,SPRN_MAS3
179 #ifdef CONFIG_PHYS_64BIT
180 mfspr r23,SPRN_MAS7
181 #endif
182 and r8,r6,r8
183 subfic r9,r6,-4096
184 and r9,r9,r7
186 or r25,r8,r9
187 ori r8,r25,(MAS3_SX|MAS3_SW|MAS3_SR)
189 /* Just modify the entry ID and EPN for the temp mapping */
190 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
191 rlwimi r7,r5,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r5) */
192 mtspr SPRN_MAS0,r7
193 xori r6,r4,1 /* Setup TMP mapping in the other Address space */
194 slwi r6,r6,12
195 oris r6,r6,(MAS1_VALID|MAS1_IPROT)@h
196 ori r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_4K))@l
197 mtspr SPRN_MAS1,r6
198 mfspr r6,SPRN_MAS2
199 li r7,0 /* temp EPN = 0 */
200 rlwimi r7,r6,0,20,31
201 mtspr SPRN_MAS2,r7
202 mtspr SPRN_MAS3,r8
203 tlbwe
205 xori r6,r4,1
206 slwi r6,r6,5 /* setup new context with other address space */
207 bl 1f /* Find our address */
208 1: mflr r9
209 rlwimi r7,r9,0,20,31
210 addi r7,r7,24
211 mtspr SPRN_SRR0,r7
212 mtspr SPRN_SRR1,r6
213 rfi
215 /* 4. Clear out PIDs & Search info */
216 li r6,0
217 mtspr SPRN_PID0,r6
218 #ifndef CONFIG_E200
219 mtspr SPRN_PID1,r6
220 mtspr SPRN_PID2,r6
221 #endif
222 mtspr SPRN_MAS6,r6
224 /* 5. Invalidate mapping we started in */
225 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
226 rlwimi r7,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */
227 mtspr SPRN_MAS0,r7
228 tlbre
229 mfspr r6,SPRN_MAS1
230 rlwinm r6,r6,0,2,0 /* clear IPROT */
231 mtspr SPRN_MAS1,r6
232 tlbwe
233 /* Invalidate TLB1 */
234 li r9,0x0c
235 tlbivax 0,r9
236 TLBSYNC
238 /* 6. Setup KERNELBASE mapping in TLB1[0] */
239 lis r6,0x1000 /* Set MAS0(TLBSEL) = TLB1(1), ESEL = 0 */
240 mtspr SPRN_MAS0,r6
241 lis r6,(MAS1_VALID|MAS1_IPROT)@h
242 ori r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_64M))@l
243 mtspr SPRN_MAS1,r6
244 li r7,0
245 lis r6,PAGE_OFFSET@h
246 ori r6,r6,PAGE_OFFSET@l
247 rlwimi r6,r7,0,20,31
248 mtspr SPRN_MAS2,r6
249 mtspr SPRN_MAS3,r8
250 tlbwe
252 /* 7. Jump to KERNELBASE mapping */
253 lis r6,KERNELBASE@h
254 ori r6,r6,KERNELBASE@l
255 rlwimi r6,r7,0,20,31
256 lis r7,MSR_KERNEL@h
257 ori r7,r7,MSR_KERNEL@l
258 bl 1f /* Find our address */
259 1: mflr r9
260 rlwimi r6,r9,0,20,31
261 addi r6,r6,24
262 mtspr SPRN_SRR0,r6
263 mtspr SPRN_SRR1,r7
264 rfi /* start execution out of TLB1[0] entry */
266 /* 8. Clear out the temp mapping */
267 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
268 rlwimi r7,r5,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r5) */
269 mtspr SPRN_MAS0,r7
270 tlbre
271 mfspr r8,SPRN_MAS1
272 rlwinm r8,r8,0,2,0 /* clear IPROT */
273 mtspr SPRN_MAS1,r8
274 tlbwe
275 /* Invalidate TLB1 */
276 li r9,0x0c
277 tlbivax 0,r9
278 TLBSYNC
280 /* Establish the interrupt vector offsets */
281 SET_IVOR(0, CriticalInput);
282 SET_IVOR(1, MachineCheck);
283 SET_IVOR(2, DataStorage);
284 SET_IVOR(3, InstructionStorage);
285 SET_IVOR(4, ExternalInput);
286 SET_IVOR(5, Alignment);
287 SET_IVOR(6, Program);
288 SET_IVOR(7, FloatingPointUnavailable);
289 SET_IVOR(8, SystemCall);
290 SET_IVOR(9, AuxillaryProcessorUnavailable);
291 SET_IVOR(10, Decrementer);
292 SET_IVOR(11, FixedIntervalTimer);
293 SET_IVOR(12, WatchdogTimer);
294 SET_IVOR(13, DataTLBError);
295 SET_IVOR(14, InstructionTLBError);
296 SET_IVOR(15, DebugDebug);
297 #if defined(CONFIG_E500) && !defined(CONFIG_PPC_E500MC)
298 SET_IVOR(15, DebugCrit);
299 #endif
300 SET_IVOR(32, SPEUnavailable);
301 SET_IVOR(33, SPEFloatingPointData);
302 SET_IVOR(34, SPEFloatingPointRound);
303 #ifndef CONFIG_E200
304 SET_IVOR(35, PerformanceMonitor);
305 #endif
306 #ifdef CONFIG_PPC_E500MC
307 SET_IVOR(36, Doorbell);
308 #endif
310 /* Establish the interrupt vector base */
311 lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
312 mtspr SPRN_IVPR,r4
314 /* Setup the defaults for TLB entries */
315 li r2,(MAS4_TSIZED(BOOKE_PAGESZ_4K))@l
316 #ifdef CONFIG_E200
317 oris r2,r2,MAS4_TLBSELD(1)@h
318 #endif
319 mtspr SPRN_MAS4, r2
321 #if 0
322 /* Enable DOZE */
323 mfspr r2,SPRN_HID0
324 oris r2,r2,HID0_DOZE@h
325 mtspr SPRN_HID0, r2
326 #endif
327 #ifdef CONFIG_E200
328 /* enable dedicated debug exception handling resources (Debug APU) */
329 mfspr r2,SPRN_HID0
330 ori r2,r2,HID0_DAPUEN@l
331 mtspr SPRN_HID0,r2
332 #endif
334 #if !defined(CONFIG_BDI_SWITCH)
335 /*
336 * The Abatron BDI JTAG debugger does not tolerate others
337 * mucking with the debug registers.
338 */
339 lis r2,DBCR0_IDM@h
340 mtspr SPRN_DBCR0,r2
341 isync
342 /* clear any residual debug events */
343 li r2,-1
344 mtspr SPRN_DBSR,r2
345 #endif
347 /*
348 * This is where the main kernel code starts.
349 */
351 /* ptr to current */
352 lis r2,init_task@h
353 ori r2,r2,init_task@l
355 /* ptr to current thread */
356 addi r4,r2,THREAD /* init task's THREAD */
357 mtspr SPRN_SPRG3,r4
359 /* stack */
360 lis r1,init_thread_union@h
361 ori r1,r1,init_thread_union@l
362 li r0,0
363 stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
365 bl early_init
367 #ifdef CONFIG_RELOCATABLE
368 lis r3,kernstart_addr@ha
369 la r3,kernstart_addr@l(r3)
370 #ifdef CONFIG_PHYS_64BIT
371 stw r23,0(r3)
372 stw r25,4(r3)
373 #else
374 stw r25,0(r3)
375 #endif
376 #endif
378 mfspr r3,SPRN_TLB1CFG
379 andi. r3,r3,0xfff
380 lis r4,num_tlbcam_entries@ha
381 stw r3,num_tlbcam_entries@l(r4)
382 /*
383 * Decide what sort of machine this is and initialize the MMU.
384 */
385 mr r3,r31
386 mr r4,r30
387 mr r5,r29
388 mr r6,r28
389 mr r7,r27
390 bl machine_init
391 bl MMU_init
393 /* Setup PTE pointers for the Abatron bdiGDB */
394 lis r6, swapper_pg_dir@h
395 ori r6, r6, swapper_pg_dir@l
396 lis r5, abatron_pteptrs@h
397 ori r5, r5, abatron_pteptrs@l
398 lis r4, KERNELBASE@h
399 ori r4, r4, KERNELBASE@l
400 stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */
401 stw r6, 0(r5)
403 /* Let's move on */
404 lis r4,start_kernel@h
405 ori r4,r4,start_kernel@l
406 lis r3,MSR_KERNEL@h
407 ori r3,r3,MSR_KERNEL@l
408 mtspr SPRN_SRR0,r4
409 mtspr SPRN_SRR1,r3
410 rfi /* change context and jump to start_kernel */
412 /* Macros to hide the PTE size differences
413 *
414 * FIND_PTE -- walks the page tables given EA & pgdir pointer
415 * r10 -- EA of fault
416 * r11 -- PGDIR pointer
417 * r12 -- free
418 * label 2: is the bailout case
419 *
420 * if we find the pte (fall through):
421 * r11 is low pte word
422 * r12 is pointer to the pte
423 */
424 #ifdef CONFIG_PTE_64BIT
425 #define PTE_FLAGS_OFFSET 4
426 #define FIND_PTE \
427 rlwinm r12, r10, 13, 19, 29; /* Compute pgdir/pmd offset */ \
428 lwzx r11, r12, r11; /* Get pgd/pmd entry */ \
429 rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \
430 beq 2f; /* Bail if no table */ \
431 rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \
432 lwz r11, 4(r12); /* Get pte entry */
433 #else
434 #define PTE_FLAGS_OFFSET 0
435 #define FIND_PTE \
436 rlwimi r11, r10, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \
437 lwz r11, 0(r11); /* Get L1 entry */ \
438 rlwinm. r12, r11, 0, 0, 19; /* Extract L2 (pte) base address */ \
439 beq 2f; /* Bail if no table */ \
440 rlwimi r12, r10, 22, 20, 29; /* Compute PTE address */ \
441 lwz r11, 0(r12); /* Get Linux PTE */
442 #endif
444 /*
445 * Interrupt vector entry code
446 *
447 * The Book E MMUs are always on so we don't need to handle
448 * interrupts in real mode as with previous PPC processors. In
449 * this case we handle interrupts in the kernel virtual address
450 * space.
451 *
452 * Interrupt vectors are dynamically placed relative to the
453 * interrupt prefix as determined by the address of interrupt_base.
454 * The interrupt vectors offsets are programmed using the labels
455 * for each interrupt vector entry.
456 *
457 * Interrupt vectors must be aligned on a 16 byte boundary.
458 * We align on a 32 byte cache line boundary for good measure.
459 */
461 interrupt_base:
462 /* Critical Input Interrupt */
463 CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception)
465 /* Machine Check Interrupt */
466 #ifdef CONFIG_E200
467 /* no RFMCI, MCSRRs on E200 */
468 CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception)
469 #else
470 MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception)
471 #endif
473 /* Data Storage Interrupt */
474 START_EXCEPTION(DataStorage)
475 NORMAL_EXCEPTION_PROLOG
476 mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */
477 stw r5,_ESR(r11)
478 mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */
479 andis. r10,r5,(ESR_ILK|ESR_DLK)@h
480 bne 1f
481 EXC_XFER_EE_LITE(0x0300, handle_page_fault)
482 1:
483 addi r3,r1,STACK_FRAME_OVERHEAD
484 EXC_XFER_EE_LITE(0x0300, CacheLockingException)
486 /* Instruction Storage Interrupt */
487 INSTRUCTION_STORAGE_EXCEPTION
489 /* External Input Interrupt */
490 EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE)
492 /* Alignment Interrupt */
493 ALIGNMENT_EXCEPTION
495 /* Program Interrupt */
496 PROGRAM_EXCEPTION
498 /* Floating Point Unavailable Interrupt */
499 #ifdef CONFIG_PPC_FPU
500 FP_UNAVAILABLE_EXCEPTION
501 #else
502 #ifdef CONFIG_E200
503 /* E200 treats 'normal' floating point instructions as FP Unavail exception */
504 EXCEPTION(0x0800, FloatingPointUnavailable, program_check_exception, EXC_XFER_EE)
505 #else
506 EXCEPTION(0x0800, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
507 #endif
508 #endif
510 /* System Call Interrupt */
511 START_EXCEPTION(SystemCall)
512 NORMAL_EXCEPTION_PROLOG
513 EXC_XFER_EE_LITE(0x0c00, DoSyscall)
515 /* Auxillary Processor Unavailable Interrupt */
516 EXCEPTION(0x2900, AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE)
518 /* Decrementer Interrupt */
519 DECREMENTER_EXCEPTION
521 /* Fixed Internal Timer Interrupt */
522 /* TODO: Add FIT support */
523 EXCEPTION(0x3100, FixedIntervalTimer, unknown_exception, EXC_XFER_EE)
525 /* Watchdog Timer Interrupt */
526 #ifdef CONFIG_BOOKE_WDT
527 CRITICAL_EXCEPTION(0x3200, WatchdogTimer, WatchdogException)
528 #else
529 CRITICAL_EXCEPTION(0x3200, WatchdogTimer, unknown_exception)
530 #endif
532 /* Data TLB Error Interrupt */
533 START_EXCEPTION(DataTLBError)
534 mtspr SPRN_SPRG0, r10 /* Save some working registers */
535 mtspr SPRN_SPRG1, r11
536 mtspr SPRN_SPRG4W, r12
537 mtspr SPRN_SPRG5W, r13
538 mfcr r11
539 mtspr SPRN_SPRG7W, r11
540 mfspr r10, SPRN_DEAR /* Get faulting address */
542 /* If we are faulting a kernel address, we have to use the
543 * kernel page tables.
544 */
545 lis r11, PAGE_OFFSET@h
546 cmplw 5, r10, r11
547 blt 5, 3f
548 lis r11, swapper_pg_dir@h
549 ori r11, r11, swapper_pg_dir@l
551 mfspr r12,SPRN_MAS1 /* Set TID to 0 */
552 rlwinm r12,r12,0,16,1
553 mtspr SPRN_MAS1,r12
555 b 4f
557 /* Get the PGD for the current thread */
558 3:
559 mfspr r11,SPRN_SPRG3
560 lwz r11,PGDIR(r11)
562 4:
563 /* Mask of required permission bits. Note that while we
564 * do copy ESR:ST to _PAGE_RW position as trying to write
565 * to an RO page is pretty common, we don't do it with
566 * _PAGE_DIRTY. We could do it, but it's a fairly rare
567 * event so I'd rather take the overhead when it happens
568 * rather than adding an instruction here. We should measure
569 * whether the whole thing is worth it in the first place
570 * as we could avoid loading SPRN_ESR completely in the first
571 * place...
572 *
573 * TODO: Is it worth doing that mfspr & rlwimi in the first
574 * place or can we save a couple of instructions here ?
575 */
576 mfspr r12,SPRN_ESR
577 li r13,_PAGE_PRESENT|_PAGE_ACCESSED
578 rlwimi r13,r12,11,29,29
580 FIND_PTE
581 andc. r13,r13,r11 /* Check permission */
583 #ifdef CONFIG_PTE_64BIT
584 #ifdef CONFIG_SMP
585 subf r10,r11,r12 /* create false data dep */
586 lwzx r13,r11,r10 /* Get upper pte bits */
587 #else
588 lwz r13,0(r12) /* Get upper pte bits */
589 #endif
590 #endif
592 bne 2f /* Bail if permission/valid mismach */
594 /* Jump to common tlb load */
595 b finish_tlb_load
596 2:
597 /* The bailout. Restore registers to pre-exception conditions
598 * and call the heavyweights to help us out.
599 */
600 mfspr r11, SPRN_SPRG7R
601 mtcr r11
602 mfspr r13, SPRN_SPRG5R
603 mfspr r12, SPRN_SPRG4R
604 mfspr r11, SPRN_SPRG1
605 mfspr r10, SPRN_SPRG0
606 b DataStorage
608 /* Instruction TLB Error Interrupt */
609 /*
610 * Nearly the same as above, except we get our
611 * information from different registers and bailout
612 * to a different point.
613 */
614 START_EXCEPTION(InstructionTLBError)
615 mtspr SPRN_SPRG0, r10 /* Save some working registers */
616 mtspr SPRN_SPRG1, r11
617 mtspr SPRN_SPRG4W, r12
618 mtspr SPRN_SPRG5W, r13
619 mfcr r11
620 mtspr SPRN_SPRG7W, r11
621 mfspr r10, SPRN_SRR0 /* Get faulting address */
623 /* If we are faulting a kernel address, we have to use the
624 * kernel page tables.
625 */
626 lis r11, PAGE_OFFSET@h
627 cmplw 5, r10, r11
628 blt 5, 3f
629 lis r11, swapper_pg_dir@h
630 ori r11, r11, swapper_pg_dir@l
632 mfspr r12,SPRN_MAS1 /* Set TID to 0 */
633 rlwinm r12,r12,0,16,1
634 mtspr SPRN_MAS1,r12
636 b 4f
638 /* Get the PGD for the current thread */
639 3:
640 mfspr r11,SPRN_SPRG3
641 lwz r11,PGDIR(r11)
643 4:
644 /* Make up the required permissions */
645 li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_HWEXEC
647 FIND_PTE
648 andc. r13,r13,r11 /* Check permission */
650 #ifdef CONFIG_PTE_64BIT
651 #ifdef CONFIG_SMP
652 subf r10,r11,r12 /* create false data dep */
653 lwzx r13,r11,r10 /* Get upper pte bits */
654 #else
655 lwz r13,0(r12) /* Get upper pte bits */
656 #endif
657 #endif
659 bne 2f /* Bail if permission mismach */
661 #ifdef CONFIG_PTE_64BIT
662 lwz r13,0(r12)
663 #endif
665 /* Jump to common TLB load point */
666 b finish_tlb_load
668 2:
669 /* The bailout. Restore registers to pre-exception conditions
670 * and call the heavyweights to help us out.
671 */
672 mfspr r11, SPRN_SPRG7R
673 mtcr r11
674 mfspr r13, SPRN_SPRG5R
675 mfspr r12, SPRN_SPRG4R
676 mfspr r11, SPRN_SPRG1
677 mfspr r10, SPRN_SPRG0
678 b InstructionStorage
680 #ifdef CONFIG_SPE
681 /* SPE Unavailable */
682 START_EXCEPTION(SPEUnavailable)
683 NORMAL_EXCEPTION_PROLOG
684 bne load_up_spe
685 addi r3,r1,STACK_FRAME_OVERHEAD
686 EXC_XFER_EE_LITE(0x2010, KernelSPE)
687 #else
688 EXCEPTION(0x2020, SPEUnavailable, unknown_exception, EXC_XFER_EE)
689 #endif /* CONFIG_SPE */
691 /* SPE Floating Point Data */
692 #ifdef CONFIG_SPE
693 EXCEPTION(0x2030, SPEFloatingPointData, SPEFloatingPointException, EXC_XFER_EE);
694 #else
695 EXCEPTION(0x2040, SPEFloatingPointData, unknown_exception, EXC_XFER_EE)
696 #endif /* CONFIG_SPE */
698 /* SPE Floating Point Round */
699 EXCEPTION(0x2050, SPEFloatingPointRound, unknown_exception, EXC_XFER_EE)
701 /* Performance Monitor */
702 EXCEPTION(0x2060, PerformanceMonitor, performance_monitor_exception, EXC_XFER_STD)
704 #ifdef CONFIG_PPC_E500MC
705 EXCEPTION(0x2070, Doorbell, unknown_exception, EXC_XFER_EE)
706 #endif
708 /* Debug Interrupt */
709 DEBUG_DEBUG_EXCEPTION
710 #if defined(CONFIG_E500) && !defined(CONFIG_PPC_E500MC)
711 DEBUG_CRIT_EXCEPTION
712 #endif
714 /*
715 * Local functions
716 */
718 /*
719 * Both the instruction and data TLB miss get to this
720 * point to load the TLB.
721 * r10 - available to use
722 * r11 - TLB (info from Linux PTE)
723 * r12 - available to use
724 * r13 - upper bits of PTE (if PTE_64BIT) or available to use
725 * CR5 - results of addr >= PAGE_OFFSET
726 * MAS0, MAS1 - loaded with proper value when we get here
727 * MAS2, MAS3 - will need additional info from Linux PTE
728 * Upon exit, we reload everything and RFI.
729 */
730 finish_tlb_load:
731 /*
732 * We set execute, because we don't have the granularity to
733 * properly set this at the page level (Linux problem).
734 * Many of these bits are software only. Bits we don't set
735 * here we (properly should) assume have the appropriate value.
736 */
738 mfspr r12, SPRN_MAS2
739 #ifdef CONFIG_PTE_64BIT
740 rlwimi r12, r11, 26, 24, 31 /* extract ...WIMGE from pte */
741 #else
742 rlwimi r12, r11, 26, 27, 31 /* extract WIMGE from pte */
743 #endif
744 mtspr SPRN_MAS2, r12
746 li r10, (_PAGE_HWEXEC | _PAGE_PRESENT)
747 rlwimi r10, r11, 31, 29, 29 /* extract _PAGE_DIRTY into SW */
748 and r12, r11, r10
749 andi. r10, r11, _PAGE_USER /* Test for _PAGE_USER */
750 slwi r10, r12, 1
751 or r10, r10, r12
752 iseleq r12, r12, r10
754 #ifdef CONFIG_PTE_64BIT
755 2: rlwimi r12, r13, 24, 0, 7 /* grab RPN[32:39] */
756 rlwimi r12, r11, 24, 8, 19 /* grab RPN[40:51] */
757 mtspr SPRN_MAS3, r12
758 BEGIN_FTR_SECTION
759 srwi r10, r13, 8 /* grab RPN[8:31] */
760 mtspr SPRN_MAS7, r10
761 END_FTR_SECTION_IFSET(CPU_FTR_BIG_PHYS)
762 #else
763 2: rlwimi r11, r12, 0, 20, 31 /* Extract RPN from PTE and merge with perms */
764 mtspr SPRN_MAS3, r11
765 #endif
766 #ifdef CONFIG_E200
767 /* Round robin TLB1 entries assignment */
768 mfspr r12, SPRN_MAS0
770 /* Extract TLB1CFG(NENTRY) */
771 mfspr r11, SPRN_TLB1CFG
772 andi. r11, r11, 0xfff
774 /* Extract MAS0(NV) */
775 andi. r13, r12, 0xfff
776 addi r13, r13, 1
777 cmpw 0, r13, r11
778 addi r12, r12, 1
780 /* check if we need to wrap */
781 blt 7f
783 /* wrap back to first free tlbcam entry */
784 lis r13, tlbcam_index@ha
785 lwz r13, tlbcam_index@l(r13)
786 rlwimi r12, r13, 0, 20, 31
787 7:
788 mtspr SPRN_MAS0,r12
789 #endif /* CONFIG_E200 */
791 tlbwe
793 /* Done...restore registers and get out of here. */
794 mfspr r11, SPRN_SPRG7R
795 mtcr r11
796 mfspr r13, SPRN_SPRG5R
797 mfspr r12, SPRN_SPRG4R
798 mfspr r11, SPRN_SPRG1
799 mfspr r10, SPRN_SPRG0
800 rfi /* Force context change */
802 #ifdef CONFIG_SPE
803 /* Note that the SPE support is closely modeled after the AltiVec
804 * support. Changes to one are likely to be applicable to the
805 * other! */
806 load_up_spe:
807 /*
808 * Disable SPE for the task which had SPE previously,
809 * and save its SPE registers in its thread_struct.
810 * Enables SPE for use in the kernel on return.
811 * On SMP we know the SPE units are free, since we give it up every
812 * switch. -- Kumar
813 */
814 mfmsr r5
815 oris r5,r5,MSR_SPE@h
816 mtmsr r5 /* enable use of SPE now */
817 isync
818 /*
819 * For SMP, we don't do lazy SPE switching because it just gets too
820 * horrendously complex, especially when a task switches from one CPU
821 * to another. Instead we call giveup_spe in switch_to.
822 */
823 #ifndef CONFIG_SMP
824 lis r3,last_task_used_spe@ha
825 lwz r4,last_task_used_spe@l(r3)
826 cmpi 0,r4,0
827 beq 1f
828 addi r4,r4,THREAD /* want THREAD of last_task_used_spe */
829 SAVE_32EVRS(0,r10,r4)
830 evxor evr10, evr10, evr10 /* clear out evr10 */
831 evmwumiaa evr10, evr10, evr10 /* evr10 <- ACC = 0 * 0 + ACC */
832 li r5,THREAD_ACC
833 evstddx evr10, r4, r5 /* save off accumulator */
834 lwz r5,PT_REGS(r4)
835 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
836 lis r10,MSR_SPE@h
837 andc r4,r4,r10 /* disable SPE for previous task */
838 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
839 1:
840 #endif /* !CONFIG_SMP */
841 /* enable use of SPE after return */
842 oris r9,r9,MSR_SPE@h
843 mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
844 li r4,1
845 li r10,THREAD_ACC
846 stw r4,THREAD_USED_SPE(r5)
847 evlddx evr4,r10,r5
848 evmra evr4,evr4
849 REST_32EVRS(0,r10,r5)
850 #ifndef CONFIG_SMP
851 subi r4,r5,THREAD
852 stw r4,last_task_used_spe@l(r3)
853 #endif /* !CONFIG_SMP */
854 /* restore registers and return */
855 2: REST_4GPRS(3, r11)
856 lwz r10,_CCR(r11)
857 REST_GPR(1, r11)
858 mtcr r10
859 lwz r10,_LINK(r11)
860 mtlr r10
861 REST_GPR(10, r11)
862 mtspr SPRN_SRR1,r9
863 mtspr SPRN_SRR0,r12
864 REST_GPR(9, r11)
865 REST_GPR(12, r11)
866 lwz r11,GPR11(r11)
867 rfi
869 /*
870 * SPE unavailable trap from kernel - print a message, but let
871 * the task use SPE in the kernel until it returns to user mode.
872 */
873 KernelSPE:
874 lwz r3,_MSR(r1)
875 oris r3,r3,MSR_SPE@h
876 stw r3,_MSR(r1) /* enable use of SPE after return */
877 lis r3,87f@h
878 ori r3,r3,87f@l
879 mr r4,r2 /* current */
880 lwz r5,_NIP(r1)
881 bl printk
882 b ret_from_except
883 87: .string "SPE used in kernel (task=%p, pc=%x) \n"
884 .align 4,0
886 #endif /* CONFIG_SPE */
888 /*
889 * Global functions
890 */
892 /*
893 * extern void loadcam_entry(unsigned int index)
894 *
895 * Load TLBCAM[index] entry in to the L2 CAM MMU
896 */
897 _GLOBAL(loadcam_entry)
898 lis r4,TLBCAM@ha
899 addi r4,r4,TLBCAM@l
900 mulli r5,r3,20
901 add r3,r5,r4
902 lwz r4,0(r3)
903 mtspr SPRN_MAS0,r4
904 lwz r4,4(r3)
905 mtspr SPRN_MAS1,r4
906 lwz r4,8(r3)
907 mtspr SPRN_MAS2,r4
908 lwz r4,12(r3)
909 mtspr SPRN_MAS3,r4
910 tlbwe
911 isync
912 blr
914 /*
915 * extern void giveup_altivec(struct task_struct *prev)
916 *
917 * The e500 core does not have an AltiVec unit.
918 */
919 _GLOBAL(giveup_altivec)
920 blr
922 #ifdef CONFIG_SPE
923 /*
924 * extern void giveup_spe(struct task_struct *prev)
925 *
926 */
927 _GLOBAL(giveup_spe)
928 mfmsr r5
929 oris r5,r5,MSR_SPE@h
930 mtmsr r5 /* enable use of SPE now */
931 isync
932 cmpi 0,r3,0
933 beqlr- /* if no previous owner, done */
934 addi r3,r3,THREAD /* want THREAD of task */
935 lwz r5,PT_REGS(r3)
936 cmpi 0,r5,0
937 SAVE_32EVRS(0, r4, r3)
938 evxor evr6, evr6, evr6 /* clear out evr6 */
939 evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */
940 li r4,THREAD_ACC
941 evstddx evr6, r4, r3 /* save off accumulator */
942 mfspr r6,SPRN_SPEFSCR
943 stw r6,THREAD_SPEFSCR(r3) /* save spefscr register value */
944 beq 1f
945 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
946 lis r3,MSR_SPE@h
947 andc r4,r4,r3 /* disable SPE for previous task */
948 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
949 1:
950 #ifndef CONFIG_SMP
951 li r5,0
952 lis r4,last_task_used_spe@ha
953 stw r5,last_task_used_spe@l(r4)
954 #endif /* !CONFIG_SMP */
955 blr
956 #endif /* CONFIG_SPE */
958 /*
959 * extern void giveup_fpu(struct task_struct *prev)
960 *
961 * Not all FSL Book-E cores have an FPU
962 */
963 #ifndef CONFIG_PPC_FPU
964 _GLOBAL(giveup_fpu)
965 blr
966 #endif
968 /*
969 * extern void abort(void)
970 *
971 * At present, this routine just applies a system reset.
972 */
973 _GLOBAL(abort)
974 li r13,0
975 mtspr SPRN_DBCR0,r13 /* disable all debug events */
976 isync
977 mfmsr r13
978 ori r13,r13,MSR_DE@l /* Enable Debug Events */
979 mtmsr r13
980 isync
981 mfspr r13,SPRN_DBCR0
982 lis r13,(DBCR0_IDM|DBCR0_RST_CHIP)@h
983 mtspr SPRN_DBCR0,r13
984 isync
986 _GLOBAL(set_context)
988 #ifdef CONFIG_BDI_SWITCH
989 /* Context switch the PTE pointer for the Abatron BDI2000.
990 * The PGDIR is the second parameter.
991 */
992 lis r5, abatron_pteptrs@h
993 ori r5, r5, abatron_pteptrs@l
994 stw r4, 0x4(r5)
995 #endif
996 mtspr SPRN_PID,r3
997 isync /* Force context change */
998 blr
1000 _GLOBAL(flush_dcache_L1)
1001 mfspr r3,SPRN_L1CFG0
1003 rlwinm r5,r3,9,3 /* Extract cache block size */
1004 twlgti r5,1 /* Only 32 and 64 byte cache blocks
1005 * are currently defined.
1006 */
1007 li r4,32
1008 subfic r6,r5,2 /* r6 = log2(1KiB / cache block size) -
1009 * log2(number of ways)
1010 */
1011 slw r5,r4,r5 /* r5 = cache block size */
1013 rlwinm r7,r3,0,0xff /* Extract number of KiB in the cache */
1014 mulli r7,r7,13 /* An 8-way cache will require 13
1015 * loads per set.
1016 */
1017 slw r7,r7,r6
1019 /* save off HID0 and set DCFA */
1020 mfspr r8,SPRN_HID0
1021 ori r9,r8,HID0_DCFA@l
1022 mtspr SPRN_HID0,r9
1023 isync
1025 lis r4,KERNELBASE@h
1026 mtctr r7
1028 1: lwz r3,0(r4) /* Load... */
1029 add r4,r4,r5
1030 bdnz 1b
1032 msync
1033 lis r4,KERNELBASE@h
1034 mtctr r7
1036 1: dcbf 0,r4 /* ...and flush. */
1037 add r4,r4,r5
1038 bdnz 1b
1040 /* restore HID0 */
1041 mtspr SPRN_HID0,r8
1042 isync
1044 blr
1046 /*
1047 * We put a few things here that have to be page-aligned. This stuff
1048 * goes at the beginning of the data segment, which is page-aligned.
1049 */
1050 .data
1051 .align 12
1052 .globl sdata
1053 sdata:
1054 .globl empty_zero_page
1055 empty_zero_page:
1056 .space 4096
1057 .globl swapper_pg_dir
1058 swapper_pg_dir:
1059 .space PGD_TABLE_SIZE
1061 /*
1062 * Room for two PTE pointers, usually the kernel and current user pointers
1063 * to their respective root page table.
1064 */
1065 abatron_pteptrs:
1066 .space 8