xref: /linux/arch/powerpc/mm/nohash/tlb_low_64e.S (revision a1c3be890440a1769ed6f822376a3e3ab0d42994)
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 *  Low level TLB miss handlers for Book3E
4 *
5 *  Copyright (C) 2008-2009
6 *      Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp.
7 */
8
9#include <linux/pgtable.h>
10#include <asm/processor.h>
11#include <asm/reg.h>
12#include <asm/page.h>
13#include <asm/mmu.h>
14#include <asm/ppc_asm.h>
15#include <asm/asm-offsets.h>
16#include <asm/cputable.h>
17#include <asm/exception-64e.h>
18#include <asm/ppc-opcode.h>
19#include <asm/kvm_asm.h>
20#include <asm/kvm_booke_hv_asm.h>
21#include <asm/feature-fixups.h>
22
23#define VPTE_PMD_SHIFT	(PTE_INDEX_SIZE)
24#define VPTE_PUD_SHIFT	(VPTE_PMD_SHIFT + PMD_INDEX_SIZE)
25#define VPTE_PGD_SHIFT	(VPTE_PUD_SHIFT + PUD_INDEX_SIZE)
26#define VPTE_INDEX_SIZE (VPTE_PGD_SHIFT + PGD_INDEX_SIZE)
27
28/**********************************************************************
29 *                                                                    *
30 * TLB miss handling for Book3E with a bolted linear mapping          *
31 * No virtual page table, no nested TLB misses                        *
32 *                                                                    *
33 **********************************************************************/
34
35/*
36 * Note that, unlike non-bolted handlers, TLB_EXFRAME is not
37 * modified by the TLB miss handlers themselves, since the TLB miss
38 * handler code will not itself cause a recursive TLB miss.
39 *
40 * TLB_EXFRAME will be modified when crit/mc/debug exceptions are
41 * entered/exited.
42 */
43.macro tlb_prolog_bolted intnum addr
44	mtspr	SPRN_SPRG_GEN_SCRATCH,r12
45	mfspr	r12,SPRN_SPRG_TLB_EXFRAME
46	std	r13,EX_TLB_R13(r12)
47	std	r10,EX_TLB_R10(r12)
48	mfspr	r13,SPRN_SPRG_PACA
49
50	mfcr	r10
51	std	r11,EX_TLB_R11(r12)
52#ifdef CONFIG_KVM_BOOKE_HV
53BEGIN_FTR_SECTION
54	mfspr	r11, SPRN_SRR1
55END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
56#endif
57	DO_KVM	\intnum, SPRN_SRR1
58	std	r16,EX_TLB_R16(r12)
59	mfspr	r16,\addr		/* get faulting address */
60	std	r14,EX_TLB_R14(r12)
61	ld	r14,PACAPGD(r13)
62	std	r15,EX_TLB_R15(r12)
63	std	r10,EX_TLB_CR(r12)
64#ifdef CONFIG_PPC_FSL_BOOK3E
65START_BTB_FLUSH_SECTION
66	mfspr r11, SPRN_SRR1
67	andi. r10,r11,MSR_PR
68	beq 1f
69	BTB_FLUSH(r10)
701:
71END_BTB_FLUSH_SECTION
72	std	r7,EX_TLB_R7(r12)
73#endif
74.endm
75
76.macro tlb_epilog_bolted
77	ld	r14,EX_TLB_CR(r12)
78#ifdef CONFIG_PPC_FSL_BOOK3E
79	ld	r7,EX_TLB_R7(r12)
80#endif
81	ld	r10,EX_TLB_R10(r12)
82	ld	r11,EX_TLB_R11(r12)
83	ld	r13,EX_TLB_R13(r12)
84	mtcr	r14
85	ld	r14,EX_TLB_R14(r12)
86	ld	r15,EX_TLB_R15(r12)
87	ld	r16,EX_TLB_R16(r12)
88	mfspr	r12,SPRN_SPRG_GEN_SCRATCH
89.endm
90
91/* Data TLB miss */
92	START_EXCEPTION(data_tlb_miss_bolted)
93	tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
94
95	/* We need _PAGE_PRESENT and  _PAGE_ACCESSED set */
96
97	/* We do the user/kernel test for the PID here along with the RW test
98	 */
99	/* We pre-test some combination of permissions to avoid double
100	 * faults:
101	 *
102	 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
103	 * ESR_ST   is 0x00800000
104	 * _PAGE_BAP_SW is 0x00000010
105	 * So the shift is >> 19. This tests for supervisor writeability.
106	 * If the page happens to be supervisor writeable and not user
107	 * writeable, we will take a new fault later, but that should be
108	 * a rare enough case.
109	 *
110	 * We also move ESR_ST in _PAGE_DIRTY position
111	 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
112	 *
113	 * MAS1 is preset for all we need except for TID that needs to
114	 * be cleared for kernel translations
115	 */
116
117	mfspr	r11,SPRN_ESR
118
119	srdi	r15,r16,60		/* get region */
120	rldicl.	r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
121	bne-	dtlb_miss_fault_bolted	/* Bail if fault addr is invalid */
122
123	rlwinm	r10,r11,32-19,27,27
124	rlwimi	r10,r11,32-16,19,19
125	cmpwi	r15,0			/* user vs kernel check */
126	ori	r10,r10,_PAGE_PRESENT
127	oris	r11,r10,_PAGE_ACCESSED@h
128
129	bne	tlb_miss_kernel_bolted
130
131tlb_miss_common_bolted:
132/*
133 * This is the guts of the TLB miss handler for bolted-linear.
134 * We are entered with:
135 *
136 * r16 = faulting address
137 * r15 = crap (free to use)
138 * r14 = page table base
139 * r13 = PACA
140 * r11 = PTE permission mask
141 * r10 = crap (free to use)
142 */
143	rldicl	r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
144	cmpldi	cr0,r14,0
145	clrrdi	r15,r15,3
146	beq	tlb_miss_fault_bolted	/* No PGDIR, bail */
147
148BEGIN_MMU_FTR_SECTION
149	/* Set the TLB reservation and search for existing entry. Then load
150	 * the entry.
151	 */
152	PPC_TLBSRX_DOT(0,R16)
153	ldx	r14,r14,r15		/* grab pgd entry */
154	beq	tlb_miss_done_bolted	/* tlb exists already, bail */
155MMU_FTR_SECTION_ELSE
156	ldx	r14,r14,r15		/* grab pgd entry */
157ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
158
159	rldicl	r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
160	clrrdi	r15,r15,3
161	cmpdi	cr0,r14,0
162	bge	tlb_miss_fault_bolted	/* Bad pgd entry or hugepage; bail */
163	ldx	r14,r14,r15		/* grab pud entry */
164
165	rldicl	r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
166	clrrdi	r15,r15,3
167	cmpdi	cr0,r14,0
168	bge	tlb_miss_fault_bolted
169	ldx	r14,r14,r15		/* Grab pmd entry */
170
171	rldicl	r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3
172	clrrdi	r15,r15,3
173	cmpdi	cr0,r14,0
174	bge	tlb_miss_fault_bolted
175	ldx	r14,r14,r15		/* Grab PTE, normal (!huge) page */
176
177	/* Check if required permissions are met */
178	andc.	r15,r11,r14
179	rldicr	r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
180	bne-	tlb_miss_fault_bolted
181
182	/* Now we build the MAS:
183	 *
184	 * MAS 0   :	Fully setup with defaults in MAS4 and TLBnCFG
185	 * MAS 1   :	Almost fully setup
186	 *               - PID already updated by caller if necessary
187	 *               - TSIZE need change if !base page size, not
188	 *                 yet implemented for now
189	 * MAS 2   :	Defaults not useful, need to be redone
190	 * MAS 3+7 :	Needs to be done
191	 */
192	clrrdi	r11,r16,12		/* Clear low crap in EA */
193	clrldi	r15,r15,12		/* Clear crap at the top */
194	rlwimi	r11,r14,32-19,27,31	/* Insert WIMGE */
195	rlwimi	r15,r14,32-8,22,25	/* Move in U bits */
196	mtspr	SPRN_MAS2,r11
197	andi.	r11,r14,_PAGE_DIRTY
198	rlwimi	r15,r14,32-2,26,31	/* Move in BAP bits */
199
200	/* Mask out SW and UW if !DIRTY (XXX optimize this !) */
201	bne	1f
202	li	r11,MAS3_SW|MAS3_UW
203	andc	r15,r15,r11
2041:
205	mtspr	SPRN_MAS7_MAS3,r15
206	tlbwe
207
208tlb_miss_done_bolted:
209	tlb_epilog_bolted
210	rfi
211
212itlb_miss_kernel_bolted:
213	li	r11,_PAGE_PRESENT|_PAGE_BAP_SX	/* Base perm */
214	oris	r11,r11,_PAGE_ACCESSED@h
215tlb_miss_kernel_bolted:
216	mfspr	r10,SPRN_MAS1
217	ld	r14,PACA_KERNELPGD(r13)
218	cmpldi	cr0,r15,8		/* Check for vmalloc region */
219	rlwinm	r10,r10,0,16,1		/* Clear TID */
220	mtspr	SPRN_MAS1,r10
221	beq+	tlb_miss_common_bolted
222
223tlb_miss_fault_bolted:
224	/* We need to check if it was an instruction miss */
225	andi.	r10,r11,_PAGE_EXEC|_PAGE_BAP_SX
226	bne	itlb_miss_fault_bolted
227dtlb_miss_fault_bolted:
228	tlb_epilog_bolted
229	b	exc_data_storage_book3e
230itlb_miss_fault_bolted:
231	tlb_epilog_bolted
232	b	exc_instruction_storage_book3e
233
234/* Instruction TLB miss */
235	START_EXCEPTION(instruction_tlb_miss_bolted)
236	tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
237
238	rldicl.	r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
239	srdi	r15,r16,60		/* get region */
240	bne-	itlb_miss_fault_bolted
241
242	li	r11,_PAGE_PRESENT|_PAGE_EXEC	/* Base perm */
243
244	/* We do the user/kernel test for the PID here along with the RW test
245	 */
246
247	cmpldi	cr0,r15,0			/* Check for user region */
248	oris	r11,r11,_PAGE_ACCESSED@h
249	beq	tlb_miss_common_bolted
250	b	itlb_miss_kernel_bolted
251
252#ifdef CONFIG_PPC_FSL_BOOK3E
253/*
254 * TLB miss handling for e6500 and derivatives, using hardware tablewalk.
255 *
256 * Linear mapping is bolted: no virtual page table or nested TLB misses
257 * Indirect entries in TLB1, hardware loads resulting direct entries
258 *    into TLB0
259 * No HES or NV hint on TLB1, so we need to do software round-robin
260 * No tlbsrx. so we need a spinlock, and we have to deal
261 *    with MAS-damage caused by tlbsx
262 * 4K pages only
263 */
264
265	START_EXCEPTION(instruction_tlb_miss_e6500)
266	tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
267
268	ld	r11,PACA_TCD_PTR(r13)
269	srdi.	r15,r16,60		/* get region */
270	ori	r16,r16,1
271
272	bne	tlb_miss_kernel_e6500	/* user/kernel test */
273
274	b	tlb_miss_common_e6500
275
276	START_EXCEPTION(data_tlb_miss_e6500)
277	tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
278
279	ld	r11,PACA_TCD_PTR(r13)
280	srdi.	r15,r16,60		/* get region */
281	rldicr	r16,r16,0,62
282
283	bne	tlb_miss_kernel_e6500	/* user vs kernel check */
284
285/*
286 * This is the guts of the TLB miss handler for e6500 and derivatives.
287 * We are entered with:
288 *
289 * r16 = page of faulting address (low bit 0 if data, 1 if instruction)
290 * r15 = crap (free to use)
291 * r14 = page table base
292 * r13 = PACA
293 * r11 = tlb_per_core ptr
294 * r10 = crap (free to use)
295 * r7  = esel_next
296 */
297tlb_miss_common_e6500:
298	crmove	cr2*4+2,cr0*4+2		/* cr2.eq != 0 if kernel address */
299
300BEGIN_FTR_SECTION		/* CPU_FTR_SMT */
301	/*
302	 * Search if we already have an indirect entry for that virtual
303	 * address, and if we do, bail out.
304	 *
305	 * MAS6:IND should be already set based on MAS4
306	 */
307	lhz	r10,PACAPACAINDEX(r13)
308	addi	r10,r10,1
309	crclr	cr1*4+eq	/* set cr1.eq = 0 for non-recursive */
3101:	lbarx	r15,0,r11
311	cmpdi	r15,0
312	bne	2f
313	stbcx.	r10,0,r11
314	bne	1b
3153:
316	.subsection 1
3172:	cmpd	cr1,r15,r10	/* recursive lock due to mcheck/crit/etc? */
318	beq	cr1,3b		/* unlock will happen if cr1.eq = 0 */
31910:	lbz	r15,0(r11)
320	cmpdi	r15,0
321	bne	10b
322	b	1b
323	.previous
324END_FTR_SECTION_IFSET(CPU_FTR_SMT)
325
326	lbz	r7,TCD_ESEL_NEXT(r11)
327
328BEGIN_FTR_SECTION		/* CPU_FTR_SMT */
329	/*
330	 * Erratum A-008139 says that we can't use tlbwe to change
331	 * an indirect entry in any way (including replacing or
332	 * invalidating) if the other thread could be in the process
333	 * of a lookup.  The workaround is to invalidate the entry
334	 * with tlbilx before overwriting.
335	 */
336
337	rlwinm	r10,r7,16,0xff0000
338	oris	r10,r10,MAS0_TLBSEL(1)@h
339	mtspr	SPRN_MAS0,r10
340	isync
341	tlbre
342	mfspr	r15,SPRN_MAS1
343	andis.	r15,r15,MAS1_VALID@h
344	beq	5f
345
346BEGIN_FTR_SECTION_NESTED(532)
347	mfspr	r10,SPRN_MAS8
348	rlwinm	r10,r10,0,0x80000fff  /* tgs,tlpid -> sgs,slpid */
349	mtspr	SPRN_MAS5,r10
350END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
351
352	mfspr	r10,SPRN_MAS1
353	rlwinm	r15,r10,0,0x3fff0000  /* tid -> spid */
354	rlwimi	r15,r10,20,0x00000003 /* ind,ts -> sind,sas */
355	mfspr	r10,SPRN_MAS6
356	mtspr	SPRN_MAS6,r15
357
358	mfspr	r15,SPRN_MAS2
359	isync
360	tlbilxva 0,r15
361	isync
362
363	mtspr	SPRN_MAS6,r10
364
3655:
366BEGIN_FTR_SECTION_NESTED(532)
367	li	r10,0
368	mtspr	SPRN_MAS8,r10
369	mtspr	SPRN_MAS5,r10
370END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
371
372	tlbsx	0,r16
373	mfspr	r10,SPRN_MAS1
374	andis.	r15,r10,MAS1_VALID@h
375	bne	tlb_miss_done_e6500
376FTR_SECTION_ELSE
377	mfspr	r10,SPRN_MAS1
378ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT)
379
380	oris	r10,r10,MAS1_VALID@h
381	beq	cr2,4f
382	rlwinm	r10,r10,0,16,1		/* Clear TID */
3834:	mtspr	SPRN_MAS1,r10
384
385	/* Now, we need to walk the page tables. First check if we are in
386	 * range.
387	 */
388	rldicl.	r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
389	bne-	tlb_miss_fault_e6500
390
391	rldicl	r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
392	cmpldi	cr0,r14,0
393	clrrdi	r15,r15,3
394	beq-	tlb_miss_fault_e6500 /* No PGDIR, bail */
395	ldx	r14,r14,r15		/* grab pgd entry */
396
397	rldicl	r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
398	clrrdi	r15,r15,3
399	cmpdi	cr0,r14,0
400	bge	tlb_miss_huge_e6500	/* Bad pgd entry or hugepage; bail */
401	ldx	r14,r14,r15		/* grab pud entry */
402
403	rldicl	r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
404	clrrdi	r15,r15,3
405	cmpdi	cr0,r14,0
406	bge	tlb_miss_huge_e6500
407	ldx	r14,r14,r15		/* Grab pmd entry */
408
409	mfspr	r10,SPRN_MAS0
410	cmpdi	cr0,r14,0
411	bge	tlb_miss_huge_e6500
412
413	/* Now we build the MAS for a 2M indirect page:
414	 *
415	 * MAS 0   :	ESEL needs to be filled by software round-robin
416	 * MAS 1   :	Fully set up
417	 *               - PID already updated by caller if necessary
418	 *               - TSIZE for now is base ind page size always
419	 *               - TID already cleared if necessary
420	 * MAS 2   :	Default not 2M-aligned, need to be redone
421	 * MAS 3+7 :	Needs to be done
422	 */
423
424	ori	r14,r14,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
425	mtspr	SPRN_MAS7_MAS3,r14
426
427	clrrdi	r15,r16,21		/* make EA 2M-aligned */
428	mtspr	SPRN_MAS2,r15
429
430tlb_miss_huge_done_e6500:
431	lbz	r16,TCD_ESEL_MAX(r11)
432	lbz	r14,TCD_ESEL_FIRST(r11)
433	rlwimi	r10,r7,16,0x00ff0000	/* insert esel_next into MAS0 */
434	addi	r7,r7,1			/* increment esel_next */
435	mtspr	SPRN_MAS0,r10
436	cmpw	r7,r16
437	iseleq	r7,r14,r7		/* if next == last use first */
438	stb	r7,TCD_ESEL_NEXT(r11)
439
440	tlbwe
441
442tlb_miss_done_e6500:
443	.macro	tlb_unlock_e6500
444BEGIN_FTR_SECTION
445	beq	cr1,1f		/* no unlock if lock was recursively grabbed */
446	li	r15,0
447	isync
448	stb	r15,0(r11)
4491:
450END_FTR_SECTION_IFSET(CPU_FTR_SMT)
451	.endm
452
453	tlb_unlock_e6500
454	tlb_epilog_bolted
455	rfi
456
457tlb_miss_huge_e6500:
458	beq	tlb_miss_fault_e6500
459	li	r10,1
460	andi.	r15,r14,HUGEPD_SHIFT_MASK@l /* r15 = psize */
461	rldimi	r14,r10,63,0		/* Set PD_HUGE */
462	xor	r14,r14,r15		/* Clear size bits */
463	ldx	r14,0,r14
464
465	/*
466	 * Now we build the MAS for a huge page.
467	 *
468	 * MAS 0   :	ESEL needs to be filled by software round-robin
469	 *		 - can be handled by indirect code
470	 * MAS 1   :	Need to clear IND and set TSIZE
471	 * MAS 2,3+7:	Needs to be redone similar to non-tablewalk handler
472	 */
473
474	subi	r15,r15,10		/* Convert psize to tsize */
475	mfspr	r10,SPRN_MAS1
476	rlwinm	r10,r10,0,~MAS1_IND
477	rlwimi	r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK
478	mtspr	SPRN_MAS1,r10
479
480	li	r10,-0x400
481	sld	r15,r10,r15		/* Generate mask based on size */
482	and	r10,r16,r15
483	rldicr	r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
484	rlwimi	r10,r14,32-19,27,31	/* Insert WIMGE */
485	clrldi	r15,r15,PAGE_SHIFT	/* Clear crap at the top */
486	rlwimi	r15,r14,32-8,22,25	/* Move in U bits */
487	mtspr	SPRN_MAS2,r10
488	andi.	r10,r14,_PAGE_DIRTY
489	rlwimi	r15,r14,32-2,26,31	/* Move in BAP bits */
490
491	/* Mask out SW and UW if !DIRTY (XXX optimize this !) */
492	bne	1f
493	li	r10,MAS3_SW|MAS3_UW
494	andc	r15,r15,r10
4951:
496	mtspr	SPRN_MAS7_MAS3,r15
497
498	mfspr	r10,SPRN_MAS0
499	b	tlb_miss_huge_done_e6500
500
501tlb_miss_kernel_e6500:
502	ld	r14,PACA_KERNELPGD(r13)
503	cmpldi	cr1,r15,8		/* Check for vmalloc region */
504	beq+	cr1,tlb_miss_common_e6500
505
506tlb_miss_fault_e6500:
507	tlb_unlock_e6500
508	/* We need to check if it was an instruction miss */
509	andi.	r16,r16,1
510	bne	itlb_miss_fault_e6500
511dtlb_miss_fault_e6500:
512	tlb_epilog_bolted
513	b	exc_data_storage_book3e
514itlb_miss_fault_e6500:
515	tlb_epilog_bolted
516	b	exc_instruction_storage_book3e
517#endif /* CONFIG_PPC_FSL_BOOK3E */
518
519/**********************************************************************
520 *                                                                    *
521 * TLB miss handling for Book3E with TLB reservation and HES support  *
522 *                                                                    *
523 **********************************************************************/
524
525
526/* Data TLB miss */
527	START_EXCEPTION(data_tlb_miss)
528	TLB_MISS_PROLOG
529
530	/* Now we handle the fault proper. We only save DEAR in normal
531	 * fault case since that's the only interesting values here.
532	 * We could probably also optimize by not saving SRR0/1 in the
533	 * linear mapping case but I'll leave that for later
534	 */
535	mfspr	r14,SPRN_ESR
536	mfspr	r16,SPRN_DEAR		/* get faulting address */
537	srdi	r15,r16,60		/* get region */
538	cmpldi	cr0,r15,0xc		/* linear mapping ? */
539	beq	tlb_load_linear		/* yes -> go to linear map load */
540
541	/* The page tables are mapped virtually linear. At this point, though,
542	 * we don't know whether we are trying to fault in a first level
543	 * virtual address or a virtual page table address. We can get that
544	 * from bit 0x1 of the region ID which we have set for a page table
545	 */
546	andi.	r10,r15,0x1
547	bne-	virt_page_table_tlb_miss
548
549	std	r14,EX_TLB_ESR(r12);	/* save ESR */
550	std	r16,EX_TLB_DEAR(r12);	/* save DEAR */
551
552	 /* We need _PAGE_PRESENT and  _PAGE_ACCESSED set */
553	li	r11,_PAGE_PRESENT
554	oris	r11,r11,_PAGE_ACCESSED@h
555
556	/* We do the user/kernel test for the PID here along with the RW test
557	 */
558	cmpldi	cr0,r15,0		/* Check for user region */
559
560	/* We pre-test some combination of permissions to avoid double
561	 * faults:
562	 *
563	 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
564	 * ESR_ST   is 0x00800000
565	 * _PAGE_BAP_SW is 0x00000010
566	 * So the shift is >> 19. This tests for supervisor writeability.
567	 * If the page happens to be supervisor writeable and not user
568	 * writeable, we will take a new fault later, but that should be
569	 * a rare enough case.
570	 *
571	 * We also move ESR_ST in _PAGE_DIRTY position
572	 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
573	 *
574	 * MAS1 is preset for all we need except for TID that needs to
575	 * be cleared for kernel translations
576	 */
577	rlwimi	r11,r14,32-19,27,27
578	rlwimi	r11,r14,32-16,19,19
579	beq	normal_tlb_miss
580	/* XXX replace the RMW cycles with immediate loads + writes */
5811:	mfspr	r10,SPRN_MAS1
582	cmpldi	cr0,r15,8		/* Check for vmalloc region */
583	rlwinm	r10,r10,0,16,1		/* Clear TID */
584	mtspr	SPRN_MAS1,r10
585	beq+	normal_tlb_miss
586
587	/* We got a crappy address, just fault with whatever DEAR and ESR
588	 * are here
589	 */
590	TLB_MISS_EPILOG_ERROR
591	b	exc_data_storage_book3e
592
593/* Instruction TLB miss */
594	START_EXCEPTION(instruction_tlb_miss)
595	TLB_MISS_PROLOG
596
597	/* If we take a recursive fault, the second level handler may need
598	 * to know whether we are handling a data or instruction fault in
599	 * order to get to the right store fault handler. We provide that
600	 * info by writing a crazy value in ESR in our exception frame
601	 */
602	li	r14,-1	/* store to exception frame is done later */
603
604	/* Now we handle the fault proper. We only save DEAR in the non
605	 * linear mapping case since we know the linear mapping case will
606	 * not re-enter. We could indeed optimize and also not save SRR0/1
607	 * in the linear mapping case but I'll leave that for later
608	 *
609	 * Faulting address is SRR0 which is already in r16
610	 */
611	srdi	r15,r16,60		/* get region */
612	cmpldi	cr0,r15,0xc		/* linear mapping ? */
613	beq	tlb_load_linear		/* yes -> go to linear map load */
614
615	/* We do the user/kernel test for the PID here along with the RW test
616	 */
617	li	r11,_PAGE_PRESENT|_PAGE_EXEC	/* Base perm */
618	oris	r11,r11,_PAGE_ACCESSED@h
619
620	cmpldi	cr0,r15,0			/* Check for user region */
621	std	r14,EX_TLB_ESR(r12)		/* write crazy -1 to frame */
622	beq	normal_tlb_miss
623
624	li	r11,_PAGE_PRESENT|_PAGE_BAP_SX	/* Base perm */
625	oris	r11,r11,_PAGE_ACCESSED@h
626	/* XXX replace the RMW cycles with immediate loads + writes */
627	mfspr	r10,SPRN_MAS1
628	cmpldi	cr0,r15,8			/* Check for vmalloc region */
629	rlwinm	r10,r10,0,16,1			/* Clear TID */
630	mtspr	SPRN_MAS1,r10
631	beq+	normal_tlb_miss
632
633	/* We got a crappy address, just fault */
634	TLB_MISS_EPILOG_ERROR
635	b	exc_instruction_storage_book3e
636
637/*
638 * This is the guts of the first-level TLB miss handler for direct
639 * misses. We are entered with:
640 *
641 * r16 = faulting address
642 * r15 = region ID
643 * r14 = crap (free to use)
644 * r13 = PACA
645 * r12 = TLB exception frame in PACA
646 * r11 = PTE permission mask
647 * r10 = crap (free to use)
648 */
649normal_tlb_miss:
650	/* So we first construct the page table address. We do that by
651	 * shifting the bottom of the address (not the region ID) by
652	 * PAGE_SHIFT-3, clearing the bottom 3 bits (get a PTE ptr) and
653	 * or'ing the fourth high bit.
654	 *
655	 * NOTE: For 64K pages, we do things slightly differently in
656	 * order to handle the weird page table format used by linux
657	 */
658	ori	r10,r15,0x1
659	rldicl	r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4
660	sldi	r15,r10,60
661	clrrdi	r14,r14,3
662	or	r10,r15,r14
663
664BEGIN_MMU_FTR_SECTION
665	/* Set the TLB reservation and search for existing entry. Then load
666	 * the entry.
667	 */
668	PPC_TLBSRX_DOT(0,R16)
669	ld	r14,0(r10)
670	beq	normal_tlb_miss_done
671MMU_FTR_SECTION_ELSE
672	ld	r14,0(r10)
673ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
674
675finish_normal_tlb_miss:
676	/* Check if required permissions are met */
677	andc.	r15,r11,r14
678	bne-	normal_tlb_miss_access_fault
679
680	/* Now we build the MAS:
681	 *
682	 * MAS 0   :	Fully setup with defaults in MAS4 and TLBnCFG
683	 * MAS 1   :	Almost fully setup
684	 *               - PID already updated by caller if necessary
685	 *               - TSIZE need change if !base page size, not
686	 *                 yet implemented for now
687	 * MAS 2   :	Defaults not useful, need to be redone
688	 * MAS 3+7 :	Needs to be done
689	 *
690	 * TODO: mix up code below for better scheduling
691	 */
692	clrrdi	r11,r16,12		/* Clear low crap in EA */
693	rlwimi	r11,r14,32-19,27,31	/* Insert WIMGE */
694	mtspr	SPRN_MAS2,r11
695
696	/* Check page size, if not standard, update MAS1 */
697	rldicl	r11,r14,64-8,64-8
698	cmpldi	cr0,r11,BOOK3E_PAGESZ_4K
699	beq-	1f
700	mfspr	r11,SPRN_MAS1
701	rlwimi	r11,r14,31,21,24
702	rlwinm	r11,r11,0,21,19
703	mtspr	SPRN_MAS1,r11
7041:
705	/* Move RPN in position */
706	rldicr	r11,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
707	clrldi	r15,r11,12		/* Clear crap at the top */
708	rlwimi	r15,r14,32-8,22,25	/* Move in U bits */
709	rlwimi	r15,r14,32-2,26,31	/* Move in BAP bits */
710
711	/* Mask out SW and UW if !DIRTY (XXX optimize this !) */
712	andi.	r11,r14,_PAGE_DIRTY
713	bne	1f
714	li	r11,MAS3_SW|MAS3_UW
715	andc	r15,r15,r11
7161:
717BEGIN_MMU_FTR_SECTION
718	srdi	r16,r15,32
719	mtspr	SPRN_MAS3,r15
720	mtspr	SPRN_MAS7,r16
721MMU_FTR_SECTION_ELSE
722	mtspr	SPRN_MAS7_MAS3,r15
723ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
724
725	tlbwe
726
727normal_tlb_miss_done:
728	/* We don't bother with restoring DEAR or ESR since we know we are
729	 * level 0 and just going back to userland. They are only needed
730	 * if you are going to take an access fault
731	 */
732	TLB_MISS_EPILOG_SUCCESS
733	rfi
734
735normal_tlb_miss_access_fault:
736	/* We need to check if it was an instruction miss */
737	andi.	r10,r11,_PAGE_EXEC
738	bne	1f
739	ld	r14,EX_TLB_DEAR(r12)
740	ld	r15,EX_TLB_ESR(r12)
741	mtspr	SPRN_DEAR,r14
742	mtspr	SPRN_ESR,r15
743	TLB_MISS_EPILOG_ERROR
744	b	exc_data_storage_book3e
7451:	TLB_MISS_EPILOG_ERROR
746	b	exc_instruction_storage_book3e
747
748
749/*
750 * This is the guts of the second-level TLB miss handler for direct
751 * misses. We are entered with:
752 *
753 * r16 = virtual page table faulting address
754 * r15 = region (top 4 bits of address)
755 * r14 = crap (free to use)
756 * r13 = PACA
757 * r12 = TLB exception frame in PACA
758 * r11 = crap (free to use)
759 * r10 = crap (free to use)
760 *
761 * Note that this should only ever be called as a second level handler
762 * with the current scheme when using SW load.
763 * That means we can always get the original fault DEAR at
764 * EX_TLB_DEAR-EX_TLB_SIZE(r12)
765 *
766 * It can be re-entered by the linear mapping miss handler. However, to
767 * avoid too much complication, it will restart the whole fault at level
768 * 0 so we don't care too much about clobbers
769 *
770 * XXX That code was written back when we couldn't clobber r14. We can now,
771 * so we could probably optimize things a bit
772 */
773virt_page_table_tlb_miss:
774	/* Are we hitting a kernel page table ? */
775	andi.	r10,r15,0x8
776
777	/* The cool thing now is that r10 contains 0 for user and 8 for kernel,
778	 * and we happen to have the swapper_pg_dir at offset 8 from the user
779	 * pgdir in the PACA :-).
780	 */
781	add	r11,r10,r13
782
783	/* If kernel, we need to clear MAS1 TID */
784	beq	1f
785	/* XXX replace the RMW cycles with immediate loads + writes */
786	mfspr	r10,SPRN_MAS1
787	rlwinm	r10,r10,0,16,1			/* Clear TID */
788	mtspr	SPRN_MAS1,r10
7891:
790BEGIN_MMU_FTR_SECTION
791	/* Search if we already have a TLB entry for that virtual address, and
792	 * if we do, bail out.
793	 */
794	PPC_TLBSRX_DOT(0,R16)
795	beq	virt_page_table_tlb_miss_done
796END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
797
798	/* Now, we need to walk the page tables. First check if we are in
799	 * range.
800	 */
801	rldicl.	r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4
802	bne-	virt_page_table_tlb_miss_fault
803
804	/* Get the PGD pointer */
805	ld	r15,PACAPGD(r11)
806	cmpldi	cr0,r15,0
807	beq-	virt_page_table_tlb_miss_fault
808
809	/* Get to PGD entry */
810	rldicl	r11,r16,64-VPTE_PGD_SHIFT,64-PGD_INDEX_SIZE-3
811	clrrdi	r10,r11,3
812	ldx	r15,r10,r15
813	cmpdi	cr0,r15,0
814	bge	virt_page_table_tlb_miss_fault
815
816	/* Get to PUD entry */
817	rldicl	r11,r16,64-VPTE_PUD_SHIFT,64-PUD_INDEX_SIZE-3
818	clrrdi	r10,r11,3
819	ldx	r15,r10,r15
820	cmpdi	cr0,r15,0
821	bge	virt_page_table_tlb_miss_fault
822
823	/* Get to PMD entry */
824	rldicl	r11,r16,64-VPTE_PMD_SHIFT,64-PMD_INDEX_SIZE-3
825	clrrdi	r10,r11,3
826	ldx	r15,r10,r15
827	cmpdi	cr0,r15,0
828	bge	virt_page_table_tlb_miss_fault
829
830	/* Ok, we're all right, we can now create a kernel translation for
831	 * a 4K or 64K page from r16 -> r15.
832	 */
833	/* Now we build the MAS:
834	 *
835	 * MAS 0   :	Fully setup with defaults in MAS4 and TLBnCFG
836	 * MAS 1   :	Almost fully setup
837	 *               - PID already updated by caller if necessary
838	 *               - TSIZE for now is base page size always
839	 * MAS 2   :	Use defaults
840	 * MAS 3+7 :	Needs to be done
841	 *
842	 * So we only do MAS 2 and 3 for now...
843	 */
844	clrldi	r11,r15,4		/* remove region ID from RPN */
845	ori	r10,r11,1		/* Or-in SR */
846
847BEGIN_MMU_FTR_SECTION
848	srdi	r16,r10,32
849	mtspr	SPRN_MAS3,r10
850	mtspr	SPRN_MAS7,r16
851MMU_FTR_SECTION_ELSE
852	mtspr	SPRN_MAS7_MAS3,r10
853ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
854
855	tlbwe
856
857BEGIN_MMU_FTR_SECTION
858virt_page_table_tlb_miss_done:
859
860	/* We have overridden MAS2:EPN but currently our primary TLB miss
861	 * handler will always restore it so that should not be an issue,
862	 * if we ever optimize the primary handler to not write MAS2 on
863	 * some cases, we'll have to restore MAS2:EPN here based on the
864	 * original fault's DEAR. If we do that we have to modify the
865	 * ITLB miss handler to also store SRR0 in the exception frame
866	 * as DEAR.
867	 *
868	 * However, one nasty thing we did is we cleared the reservation
869	 * (well, potentially we did). We do a trick here thus if we
870	 * are not a level 0 exception (we interrupted the TLB miss) we
871	 * offset the return address by -4 in order to replay the tlbsrx
872	 * instruction there
873	 */
874	subf	r10,r13,r12
875	cmpldi	cr0,r10,PACA_EXTLB+EX_TLB_SIZE
876	bne-	1f
877	ld	r11,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
878	addi	r10,r11,-4
879	std	r10,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
8801:
881END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
882	/* Return to caller, normal case */
883	TLB_MISS_EPILOG_SUCCESS
884	rfi
885
886virt_page_table_tlb_miss_fault:
887	/* If we fault here, things are a little bit tricky. We need to call
888	 * either data or instruction store fault, and we need to retrieve
889	 * the original fault address and ESR (for data).
890	 *
891	 * The thing is, we know that in normal circumstances, this is
892	 * always called as a second level tlb miss for SW load or as a first
893	 * level TLB miss for HW load, so we should be able to peek at the
894	 * relevant information in the first exception frame in the PACA.
895	 *
896	 * However, we do need to double check that, because we may just hit
897	 * a stray kernel pointer or a userland attack trying to hit those
898	 * areas. If that is the case, we do a data fault. (We can't get here
899	 * from an instruction tlb miss anyway).
900	 *
901	 * Note also that when going to a fault, we must unwind the previous
902	 * level as well. Since we are doing that, we don't need to clear or
903	 * restore the TLB reservation neither.
904	 */
905	subf	r10,r13,r12
906	cmpldi	cr0,r10,PACA_EXTLB+EX_TLB_SIZE
907	bne-	virt_page_table_tlb_miss_whacko_fault
908
909	/* We dig the original DEAR and ESR from slot 0 */
910	ld	r15,EX_TLB_DEAR+PACA_EXTLB(r13)
911	ld	r16,EX_TLB_ESR+PACA_EXTLB(r13)
912
913	/* We check for the "special" ESR value for instruction faults */
914	cmpdi	cr0,r16,-1
915	beq	1f
916	mtspr	SPRN_DEAR,r15
917	mtspr	SPRN_ESR,r16
918	TLB_MISS_EPILOG_ERROR
919	b	exc_data_storage_book3e
9201:	TLB_MISS_EPILOG_ERROR
921	b	exc_instruction_storage_book3e
922
923virt_page_table_tlb_miss_whacko_fault:
924	/* The linear fault will restart everything so ESR and DEAR will
925	 * not have been clobbered, let's just fault with what we have
926	 */
927	TLB_MISS_EPILOG_ERROR
928	b	exc_data_storage_book3e
929
930
931/**************************************************************
932 *                                                            *
933 * TLB miss handling for Book3E with hw page table support    *
934 *                                                            *
935 **************************************************************/
936
937
938/* Data TLB miss */
939	START_EXCEPTION(data_tlb_miss_htw)
940	TLB_MISS_PROLOG
941
942	/* Now we handle the fault proper. We only save DEAR in normal
943	 * fault case since that's the only interesting values here.
944	 * We could probably also optimize by not saving SRR0/1 in the
945	 * linear mapping case but I'll leave that for later
946	 */
947	mfspr	r14,SPRN_ESR
948	mfspr	r16,SPRN_DEAR		/* get faulting address */
949	srdi	r11,r16,60		/* get region */
950	cmpldi	cr0,r11,0xc		/* linear mapping ? */
951	beq	tlb_load_linear		/* yes -> go to linear map load */
952
953	/* We do the user/kernel test for the PID here along with the RW test
954	 */
955	cmpldi	cr0,r11,0		/* Check for user region */
956	ld	r15,PACAPGD(r13)	/* Load user pgdir */
957	beq	htw_tlb_miss
958
959	/* XXX replace the RMW cycles with immediate loads + writes */
9601:	mfspr	r10,SPRN_MAS1
961	cmpldi	cr0,r11,8		/* Check for vmalloc region */
962	rlwinm	r10,r10,0,16,1		/* Clear TID */
963	mtspr	SPRN_MAS1,r10
964	ld	r15,PACA_KERNELPGD(r13)	/* Load kernel pgdir */
965	beq+	htw_tlb_miss
966
967	/* We got a crappy address, just fault with whatever DEAR and ESR
968	 * are here
969	 */
970	TLB_MISS_EPILOG_ERROR
971	b	exc_data_storage_book3e
972
973/* Instruction TLB miss */
974	START_EXCEPTION(instruction_tlb_miss_htw)
975	TLB_MISS_PROLOG
976
977	/* If we take a recursive fault, the second level handler may need
978	 * to know whether we are handling a data or instruction fault in
979	 * order to get to the right store fault handler. We provide that
980	 * info by keeping a crazy value for ESR in r14
981	 */
982	li	r14,-1	/* store to exception frame is done later */
983
984	/* Now we handle the fault proper. We only save DEAR in the non
985	 * linear mapping case since we know the linear mapping case will
986	 * not re-enter. We could indeed optimize and also not save SRR0/1
987	 * in the linear mapping case but I'll leave that for later
988	 *
989	 * Faulting address is SRR0 which is already in r16
990	 */
991	srdi	r11,r16,60		/* get region */
992	cmpldi	cr0,r11,0xc		/* linear mapping ? */
993	beq	tlb_load_linear		/* yes -> go to linear map load */
994
995	/* We do the user/kernel test for the PID here along with the RW test
996	 */
997	cmpldi	cr0,r11,0			/* Check for user region */
998	ld	r15,PACAPGD(r13)		/* Load user pgdir */
999	beq	htw_tlb_miss
1000
1001	/* XXX replace the RMW cycles with immediate loads + writes */
10021:	mfspr	r10,SPRN_MAS1
1003	cmpldi	cr0,r11,8			/* Check for vmalloc region */
1004	rlwinm	r10,r10,0,16,1			/* Clear TID */
1005	mtspr	SPRN_MAS1,r10
1006	ld	r15,PACA_KERNELPGD(r13)		/* Load kernel pgdir */
1007	beq+	htw_tlb_miss
1008
1009	/* We got a crappy address, just fault */
1010	TLB_MISS_EPILOG_ERROR
1011	b	exc_instruction_storage_book3e
1012
1013
1014/*
1015 * This is the guts of the second-level TLB miss handler for direct
1016 * misses. We are entered with:
1017 *
1018 * r16 = virtual page table faulting address
1019 * r15 = PGD pointer
1020 * r14 = ESR
1021 * r13 = PACA
1022 * r12 = TLB exception frame in PACA
1023 * r11 = crap (free to use)
1024 * r10 = crap (free to use)
1025 *
1026 * It can be re-entered by the linear mapping miss handler. However, to
1027 * avoid too much complication, it will save/restore things for us
1028 */
1029htw_tlb_miss:
1030	/* Search if we already have a TLB entry for that virtual address, and
1031	 * if we do, bail out.
1032	 *
1033	 * MAS1:IND should be already set based on MAS4
1034	 */
1035	PPC_TLBSRX_DOT(0,R16)
1036	beq	htw_tlb_miss_done
1037
1038	/* Now, we need to walk the page tables. First check if we are in
1039	 * range.
1040	 */
1041	rldicl.	r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
1042	bne-	htw_tlb_miss_fault
1043
1044	/* Get the PGD pointer */
1045	cmpldi	cr0,r15,0
1046	beq-	htw_tlb_miss_fault
1047
1048	/* Get to PGD entry */
1049	rldicl	r11,r16,64-(PGDIR_SHIFT-3),64-PGD_INDEX_SIZE-3
1050	clrrdi	r10,r11,3
1051	ldx	r15,r10,r15
1052	cmpdi	cr0,r15,0
1053	bge	htw_tlb_miss_fault
1054
1055	/* Get to PUD entry */
1056	rldicl	r11,r16,64-(PUD_SHIFT-3),64-PUD_INDEX_SIZE-3
1057	clrrdi	r10,r11,3
1058	ldx	r15,r10,r15
1059	cmpdi	cr0,r15,0
1060	bge	htw_tlb_miss_fault
1061
1062	/* Get to PMD entry */
1063	rldicl	r11,r16,64-(PMD_SHIFT-3),64-PMD_INDEX_SIZE-3
1064	clrrdi	r10,r11,3
1065	ldx	r15,r10,r15
1066	cmpdi	cr0,r15,0
1067	bge	htw_tlb_miss_fault
1068
1069	/* Ok, we're all right, we can now create an indirect entry for
1070	 * a 1M or 256M page.
1071	 *
1072	 * The last trick is now that because we use "half" pages for
1073	 * the HTW (1M IND is 2K and 256M IND is 32K) we need to account
1074	 * for an added LSB bit to the RPN. For 64K pages, there is no
1075	 * problem as we already use 32K arrays (half PTE pages), but for
1076	 * 4K page we need to extract a bit from the virtual address and
1077	 * insert it into the "PA52" bit of the RPN.
1078	 */
1079	rlwimi	r15,r16,32-9,20,20
1080	/* Now we build the MAS:
1081	 *
1082	 * MAS 0   :	Fully setup with defaults in MAS4 and TLBnCFG
1083	 * MAS 1   :	Almost fully setup
1084	 *               - PID already updated by caller if necessary
1085	 *               - TSIZE for now is base ind page size always
1086	 * MAS 2   :	Use defaults
1087	 * MAS 3+7 :	Needs to be done
1088	 */
1089	ori	r10,r15,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
1090
1091BEGIN_MMU_FTR_SECTION
1092	srdi	r16,r10,32
1093	mtspr	SPRN_MAS3,r10
1094	mtspr	SPRN_MAS7,r16
1095MMU_FTR_SECTION_ELSE
1096	mtspr	SPRN_MAS7_MAS3,r10
1097ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
1098
1099	tlbwe
1100
1101htw_tlb_miss_done:
1102	/* We don't bother with restoring DEAR or ESR since we know we are
1103	 * level 0 and just going back to userland. They are only needed
1104	 * if you are going to take an access fault
1105	 */
1106	TLB_MISS_EPILOG_SUCCESS
1107	rfi
1108
1109htw_tlb_miss_fault:
1110	/* We need to check if it was an instruction miss. We know this
1111	 * though because r14 would contain -1
1112	 */
1113	cmpdi	cr0,r14,-1
1114	beq	1f
1115	mtspr	SPRN_DEAR,r16
1116	mtspr	SPRN_ESR,r14
1117	TLB_MISS_EPILOG_ERROR
1118	b	exc_data_storage_book3e
11191:	TLB_MISS_EPILOG_ERROR
1120	b	exc_instruction_storage_book3e
1121
1122/*
1123 * This is the guts of "any" level TLB miss handler for kernel linear
1124 * mapping misses. We are entered with:
1125 *
1126 *
1127 * r16 = faulting address
1128 * r15 = crap (free to use)
1129 * r14 = ESR (data) or -1 (instruction)
1130 * r13 = PACA
1131 * r12 = TLB exception frame in PACA
1132 * r11 = crap (free to use)
1133 * r10 = crap (free to use)
1134 *
1135 * In addition we know that we will not re-enter, so in theory, we could
1136 * use a simpler epilog not restoring SRR0/1 etc.. but we'll do that later.
1137 *
1138 * We also need to be careful about MAS registers here & TLB reservation,
1139 * as we know we'll have clobbered them if we interrupt the main TLB miss
1140 * handlers in which case we probably want to do a full restart at level
1141 * 0 rather than saving / restoring the MAS.
1142 *
1143 * Note: If we care about performance of that core, we can easily shuffle
1144 *       a few things around
1145 */
1146tlb_load_linear:
1147	/* For now, we assume the linear mapping is contiguous and stops at
1148	 * linear_map_top. We also assume the size is a multiple of 1G, thus
1149	 * we only use 1G pages for now. That might have to be changed in a
1150	 * final implementation, especially when dealing with hypervisors
1151	 */
1152	ld	r11,PACATOC(r13)
1153	ld	r11,linear_map_top@got(r11)
1154	ld	r10,0(r11)
1155	tovirt(10,10)
1156	cmpld	cr0,r16,r10
1157	bge	tlb_load_linear_fault
1158
1159	/* MAS1 need whole new setup. */
1160	li	r15,(BOOK3E_PAGESZ_1GB<<MAS1_TSIZE_SHIFT)
1161	oris	r15,r15,MAS1_VALID@h	/* MAS1 needs V and TSIZE */
1162	mtspr	SPRN_MAS1,r15
1163
1164	/* Already somebody there ? */
1165	PPC_TLBSRX_DOT(0,R16)
1166	beq	tlb_load_linear_done
1167
1168	/* Now we build the remaining MAS. MAS0 and 2 should be fine
1169	 * with their defaults, which leaves us with MAS 3 and 7. The
1170	 * mapping is linear, so we just take the address, clear the
1171	 * region bits, and or in the permission bits which are currently
1172	 * hard wired
1173	 */
1174	clrrdi	r10,r16,30		/* 1G page index */
1175	clrldi	r10,r10,4		/* clear region bits */
1176	ori	r10,r10,MAS3_SR|MAS3_SW|MAS3_SX
1177
1178BEGIN_MMU_FTR_SECTION
1179	srdi	r16,r10,32
1180	mtspr	SPRN_MAS3,r10
1181	mtspr	SPRN_MAS7,r16
1182MMU_FTR_SECTION_ELSE
1183	mtspr	SPRN_MAS7_MAS3,r10
1184ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
1185
1186	tlbwe
1187
1188tlb_load_linear_done:
1189	/* We use the "error" epilog for success as we do want to
1190	 * restore to the initial faulting context, whatever it was.
1191	 * We do that because we can't resume a fault within a TLB
1192	 * miss handler, due to MAS and TLB reservation being clobbered.
1193	 */
1194	TLB_MISS_EPILOG_ERROR
1195	rfi
1196
1197tlb_load_linear_fault:
1198	/* We keep the DEAR and ESR around, this shouldn't have happened */
1199	cmpdi	cr0,r14,-1
1200	beq	1f
1201	TLB_MISS_EPILOG_ERROR_SPECIAL
1202	b	exc_data_storage_book3e
12031:	TLB_MISS_EPILOG_ERROR_SPECIAL
1204	b	exc_instruction_storage_book3e
1205