1/*
2 * ppc64 MMU hashtable management routines
3 *
4 * (c) Copyright IBM Corp. 2003, 2005
5 *
6 * Maintained by: Benjamin Herrenschmidt
7 *                <benh@kernel.crashing.org>
8 *
9 * This file is covered by the GNU Public Licence v2 as
10 * described in the kernel's COPYING file.
11 */
12
13#include <asm/reg.h>
14#include <asm/pgtable.h>
15#include <asm/mmu.h>
16#include <asm/page.h>
17#include <asm/types.h>
18#include <asm/ppc_asm.h>
19#include <asm/asm-offsets.h>
20#include <asm/cputable.h>
21
22	.text
23
24/*
25 * Stackframe:
26 *
27 *         +-> Back chain			(SP + 256)
28 *         |   General register save area	(SP + 112)
29 *         |   Parameter save area		(SP + 48)
30 *         |   TOC save area			(SP + 40)
31 *         |   link editor doubleword		(SP + 32)
32 *         |   compiler doubleword		(SP + 24)
33 *         |   LR save area			(SP + 16)
34 *         |   CR save area			(SP + 8)
35 * SP ---> +-- Back chain			(SP + 0)
36 */
37
38#ifndef CONFIG_PPC_64K_PAGES
39
40/*****************************************************************************
41 *                                                                           *
42 *           4K SW & 4K HW pages implementation                              *
43 *                                                                           *
44 *****************************************************************************/
45
46
47/*
48 * _hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
49 *		 pte_t *ptep, unsigned long trap, unsigned long flags,
50 *		 int ssize)
51 *
52 * Adds a 4K page to the hash table in a segment of 4K pages only
53 */
54
55_GLOBAL(__hash_page_4K)
56	mflr	r0
57	std	r0,16(r1)
58	stdu	r1,-STACKFRAMESIZE(r1)
59	/* Save all params that we need after a function call */
60	std	r6,STK_PARAM(R6)(r1)
61	std	r8,STK_PARAM(R8)(r1)
62	std	r9,STK_PARAM(R9)(r1)
63
64	/* Save non-volatile registers.
65	 * r31 will hold "old PTE"
66	 * r30 is "new PTE"
67	 * r29 is vpn
68	 * r28 is a hash value
69	 * r27 is hashtab mask (maybe dynamic patched instead ?)
70	 */
71	std	r27,STK_REG(R27)(r1)
72	std	r28,STK_REG(R28)(r1)
73	std	r29,STK_REG(R29)(r1)
74	std	r30,STK_REG(R30)(r1)
75	std	r31,STK_REG(R31)(r1)
76
77	/* Step 1:
78	 *
79	 * Check permissions, atomically mark the linux PTE busy
80	 * and hashed.
81	 */
821:
83	ldarx	r31,0,r6
84	/* Check access rights (access & ~(pte_val(*ptep))) */
85	andc.	r0,r4,r31
86	bne-	htab_wrong_access
87	/* Check if PTE is busy */
88	andi.	r0,r31,_PAGE_BUSY
89	/* If so, just bail out and refault if needed. Someone else
90	 * is changing this PTE anyway and might hash it.
91	 */
92	bne-	htab_bail_ok
93
94	/* Prepare new PTE value (turn access RW into DIRTY, then
95	 * add BUSY,HASHPTE and ACCESSED)
96	 */
97	rlwinm	r30,r4,32-9+7,31-7,31-7	/* _PAGE_RW -> _PAGE_DIRTY */
98	or	r30,r30,r31
99	ori	r30,r30,_PAGE_BUSY | _PAGE_ACCESSED | _PAGE_HASHPTE
100	/* Write the linux PTE atomically (setting busy) */
101	stdcx.	r30,0,r6
102	bne-	1b
103	isync
104
105	/* Step 2:
106	 *
107	 * Insert/Update the HPTE in the hash table. At this point,
108	 * r4 (access) is re-useable, we use it for the new HPTE flags
109	 */
110
111BEGIN_FTR_SECTION
112	cmpdi	r9,0			/* check segment size */
113	bne	3f
114END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
115	/* Calc vpn and put it in r29 */
116	sldi	r29,r5,SID_SHIFT - VPN_SHIFT
117	rldicl  r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
118	or	r29,r28,r29
119	/*
120	 * Calculate hash value for primary slot and store it in r28
121	 * r3 = va, r5 = vsid
122	 * r0 = (va >> 12) & ((1ul << (28 - 12)) -1)
123	 */
124	rldicl	r0,r3,64-12,48
125	xor	r28,r5,r0		/* hash */
126	b	4f
127
1283:	/* Calc vpn and put it in r29 */
129	sldi	r29,r5,SID_SHIFT_1T - VPN_SHIFT
130	rldicl  r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT_1T - VPN_SHIFT)
131	or	r29,r28,r29
132
133	/*
134	 * calculate hash value for primary slot and
135	 * store it in r28 for 1T segment
136	 * r3 = va, r5 = vsid
137	 */
138	sldi	r28,r5,25		/* vsid << 25 */
139	/* r0 =  (va >> 12) & ((1ul << (40 - 12)) -1) */
140	rldicl	r0,r3,64-12,36
141	xor	r28,r28,r5		/* vsid ^ ( vsid << 25) */
142	xor	r28,r28,r0		/* hash */
143
144	/* Convert linux PTE bits into HW equivalents */
1454:	andi.	r3,r30,0x1fe		/* Get basic set of flags */
146	xori	r3,r3,HPTE_R_N		/* _PAGE_EXEC -> NOEXEC */
147	rlwinm	r0,r30,32-9+1,30,30	/* _PAGE_RW -> _PAGE_USER (r0) */
148	rlwinm	r4,r30,32-7+1,30,30	/* _PAGE_DIRTY -> _PAGE_USER (r4) */
149	and	r0,r0,r4		/* _PAGE_RW & _PAGE_DIRTY ->r0 bit 30*/
150	andc	r0,r30,r0		/* r0 = pte & ~r0 */
151	rlwimi	r3,r0,32-1,31,31	/* Insert result into PP lsb */
152	/*
153	 * Always add "C" bit for perf. Memory coherence is always enabled
154	 */
155	ori	r3,r3,HPTE_R_C | HPTE_R_M
156
157	/* We eventually do the icache sync here (maybe inline that
158	 * code rather than call a C function...)
159	 */
160BEGIN_FTR_SECTION
161	mr	r4,r30
162	mr	r5,r7
163	bl	hash_page_do_lazy_icache
164END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE)
165
166	/* At this point, r3 contains new PP bits, save them in
167	 * place of "access" in the param area (sic)
168	 */
169	std	r3,STK_PARAM(R4)(r1)
170
171	/* Get htab_hash_mask */
172	ld	r4,htab_hash_mask@got(2)
173	ld	r27,0(r4)	/* htab_hash_mask -> r27 */
174
175	/* Check if we may already be in the hashtable, in this case, we
176	 * go to out-of-line code to try to modify the HPTE
177	 */
178	andi.	r0,r31,_PAGE_HASHPTE
179	bne	htab_modify_pte
180
181htab_insert_pte:
182	/* Clear hpte bits in new pte (we also clear BUSY btw) and
183	 * add _PAGE_HASHPTE
184	 */
185	lis	r0,_PAGE_HPTEFLAGS@h
186	ori	r0,r0,_PAGE_HPTEFLAGS@l
187	andc	r30,r30,r0
188	ori	r30,r30,_PAGE_HASHPTE
189
190	/* physical address r5 */
191	rldicl	r5,r31,64-PTE_RPN_SHIFT,PTE_RPN_SHIFT
192	sldi	r5,r5,PAGE_SHIFT
193
194	/* Calculate primary group hash */
195	and	r0,r28,r27
196	rldicr	r3,r0,3,63-3		/* r3 = (hash & mask) << 3 */
197
198	/* Call ppc_md.hpte_insert */
199	ld	r6,STK_PARAM(R4)(r1)	/* Retrieve new pp bits */
200	mr	r4,r29			/* Retrieve vpn */
201	li	r7,0			/* !bolted, !secondary */
202	li	r8,MMU_PAGE_4K		/* page size */
203	li	r9,MMU_PAGE_4K		/* actual page size */
204	ld	r10,STK_PARAM(R9)(r1)	/* segment size */
205.globl htab_call_hpte_insert1
206htab_call_hpte_insert1:
207	bl	.			/* Patched by htab_finish_init() */
208	cmpdi	0,r3,0
209	bge	htab_pte_insert_ok	/* Insertion successful */
210	cmpdi	0,r3,-2			/* Critical failure */
211	beq-	htab_pte_insert_failure
212
213	/* Now try secondary slot */
214
215	/* physical address r5 */
216	rldicl	r5,r31,64-PTE_RPN_SHIFT,PTE_RPN_SHIFT
217	sldi	r5,r5,PAGE_SHIFT
218
219	/* Calculate secondary group hash */
220	andc	r0,r27,r28
221	rldicr	r3,r0,3,63-3	/* r0 = (~hash & mask) << 3 */
222
223	/* Call ppc_md.hpte_insert */
224	ld	r6,STK_PARAM(R4)(r1)	/* Retrieve new pp bits */
225	mr	r4,r29			/* Retrieve vpn */
226	li	r7,HPTE_V_SECONDARY	/* !bolted, secondary */
227	li	r8,MMU_PAGE_4K		/* page size */
228	li	r9,MMU_PAGE_4K		/* actual page size */
229	ld	r10,STK_PARAM(R9)(r1)	/* segment size */
230.globl htab_call_hpte_insert2
231htab_call_hpte_insert2:
232	bl	.			/* Patched by htab_finish_init() */
233	cmpdi	0,r3,0
234	bge+	htab_pte_insert_ok	/* Insertion successful */
235	cmpdi	0,r3,-2			/* Critical failure */
236	beq-	htab_pte_insert_failure
237
238	/* Both are full, we need to evict something */
239	mftb	r0
240	/* Pick a random group based on TB */
241	andi.	r0,r0,1
242	mr	r5,r28
243	bne	2f
244	not	r5,r5
2452:	and	r0,r5,r27
246	rldicr	r3,r0,3,63-3	/* r0 = (hash & mask) << 3 */
247	/* Call ppc_md.hpte_remove */
248.globl htab_call_hpte_remove
249htab_call_hpte_remove:
250	bl	.			/* Patched by htab_finish_init() */
251
252	/* Try all again */
253	b	htab_insert_pte
254
255htab_bail_ok:
256	li	r3,0
257	b	htab_bail
258
259htab_pte_insert_ok:
260	/* Insert slot number & secondary bit in PTE */
261	rldimi	r30,r3,12,63-15
262
263	/* Write out the PTE with a normal write
264	 * (maybe add eieio may be good still ?)
265	 */
266htab_write_out_pte:
267	ld	r6,STK_PARAM(R6)(r1)
268	std	r30,0(r6)
269	li	r3, 0
270htab_bail:
271	ld	r27,STK_REG(R27)(r1)
272	ld	r28,STK_REG(R28)(r1)
273	ld	r29,STK_REG(R29)(r1)
274	ld      r30,STK_REG(R30)(r1)
275	ld      r31,STK_REG(R31)(r1)
276	addi    r1,r1,STACKFRAMESIZE
277	ld      r0,16(r1)
278	mtlr    r0
279	blr
280
281htab_modify_pte:
282	/* Keep PP bits in r4 and slot idx from the PTE around in r3 */
283	mr	r4,r3
284	rlwinm	r3,r31,32-12,29,31
285
286	/* Secondary group ? if yes, get a inverted hash value */
287	mr	r5,r28
288	andi.	r0,r31,_PAGE_SECONDARY
289	beq	1f
290	not	r5,r5
2911:
292	/* Calculate proper slot value for ppc_md.hpte_updatepp */
293	and	r0,r5,r27
294	rldicr	r0,r0,3,63-3	/* r0 = (hash & mask) << 3 */
295	add	r3,r0,r3	/* add slot idx */
296
297	/* Call ppc_md.hpte_updatepp */
298	mr	r5,r29			/* vpn */
299	li	r6,MMU_PAGE_4K		/* base page size */
300	li	r7,MMU_PAGE_4K		/* actual page size */
301	ld	r8,STK_PARAM(R9)(r1)	/* segment size */
302	ld	r9,STK_PARAM(R8)(r1)	/* get "flags" param */
303.globl htab_call_hpte_updatepp
304htab_call_hpte_updatepp:
305	bl	.			/* Patched by htab_finish_init() */
306
307	/* if we failed because typically the HPTE wasn't really here
308	 * we try an insertion.
309	 */
310	cmpdi	0,r3,-1
311	beq-	htab_insert_pte
312
313	/* Clear the BUSY bit and Write out the PTE */
314	li	r0,_PAGE_BUSY
315	andc	r30,r30,r0
316	b	htab_write_out_pte
317
318htab_wrong_access:
319	/* Bail out clearing reservation */
320	stdcx.	r31,0,r6
321	li	r3,1
322	b	htab_bail
323
324htab_pte_insert_failure:
325	/* Bail out restoring old PTE */
326	ld	r6,STK_PARAM(R6)(r1)
327	std	r31,0(r6)
328	li	r3,-1
329	b	htab_bail
330
331
332#else /* CONFIG_PPC_64K_PAGES */
333
334
335/*****************************************************************************
336 *                                                                           *
337 *           64K SW & 4K or 64K HW in a 4K segment pages implementation      *
338 *                                                                           *
339 *****************************************************************************/
340
341/* _hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
342 *		 pte_t *ptep, unsigned long trap, unsigned local flags,
343 *		 int ssize, int subpg_prot)
344 */
345
346/*
347 * For now, we do NOT implement Admixed pages
348 */
349_GLOBAL(__hash_page_4K)
350	mflr	r0
351	std	r0,16(r1)
352	stdu	r1,-STACKFRAMESIZE(r1)
353	/* Save all params that we need after a function call */
354	std	r6,STK_PARAM(R6)(r1)
355	std	r8,STK_PARAM(R8)(r1)
356	std	r9,STK_PARAM(R9)(r1)
357
358	/* Save non-volatile registers.
359	 * r31 will hold "old PTE"
360	 * r30 is "new PTE"
361	 * r29 is vpn
362	 * r28 is a hash value
363	 * r27 is hashtab mask (maybe dynamic patched instead ?)
364	 * r26 is the hidx mask
365	 * r25 is the index in combo page
366	 */
367	std	r25,STK_REG(R25)(r1)
368	std	r26,STK_REG(R26)(r1)
369	std	r27,STK_REG(R27)(r1)
370	std	r28,STK_REG(R28)(r1)
371	std	r29,STK_REG(R29)(r1)
372	std	r30,STK_REG(R30)(r1)
373	std	r31,STK_REG(R31)(r1)
374
375	/* Step 1:
376	 *
377	 * Check permissions, atomically mark the linux PTE busy
378	 * and hashed.
379	 */
3801:
381	ldarx	r31,0,r6
382	/* Check access rights (access & ~(pte_val(*ptep))) */
383	andc.	r0,r4,r31
384	bne-	htab_wrong_access
385	/* Check if PTE is busy */
386	andi.	r0,r31,_PAGE_BUSY
387	/* If so, just bail out and refault if needed. Someone else
388	 * is changing this PTE anyway and might hash it.
389	 */
390	bne-	htab_bail_ok
391	/* Prepare new PTE value (turn access RW into DIRTY, then
392	 * add BUSY and ACCESSED)
393	 */
394	rlwinm	r30,r4,32-9+7,31-7,31-7	/* _PAGE_RW -> _PAGE_DIRTY */
395	or	r30,r30,r31
396	ori	r30,r30,_PAGE_BUSY | _PAGE_ACCESSED
397	oris	r30,r30,_PAGE_COMBO@h
398	/* Write the linux PTE atomically (setting busy) */
399	stdcx.	r30,0,r6
400	bne-	1b
401	isync
402
403	/* Step 2:
404	 *
405	 * Insert/Update the HPTE in the hash table. At this point,
406	 * r4 (access) is re-useable, we use it for the new HPTE flags
407	 */
408
409	/* Load the hidx index */
410	rldicl	r25,r3,64-12,60
411
412BEGIN_FTR_SECTION
413	cmpdi	r9,0			/* check segment size */
414	bne	3f
415END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
416	/* Calc vpn and put it in r29 */
417	sldi	r29,r5,SID_SHIFT - VPN_SHIFT
418	/*
419	 * clrldi r3,r3,64 - SID_SHIFT -->  ea & 0xfffffff
420	 * srdi	 r28,r3,VPN_SHIFT
421	 */
422	rldicl  r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
423	or	r29,r28,r29
424	/*
425	 * Calculate hash value for primary slot and store it in r28
426	 * r3 = va, r5 = vsid
427	 * r0 = (va >> 12) & ((1ul << (28 - 12)) -1)
428	 */
429	rldicl	r0,r3,64-12,48
430	xor	r28,r5,r0		/* hash */
431	b	4f
432
4333:	/* Calc vpn and put it in r29 */
434	sldi	r29,r5,SID_SHIFT_1T - VPN_SHIFT
435	/*
436	 * clrldi r3,r3,64 - SID_SHIFT_1T -->  ea & 0xffffffffff
437	 * srdi	r28,r3,VPN_SHIFT
438	 */
439	rldicl  r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT_1T - VPN_SHIFT)
440	or	r29,r28,r29
441
442	/*
443	 * Calculate hash value for primary slot and
444	 * store it in r28  for 1T segment
445	 * r3 = va, r5 = vsid
446	 */
447	sldi	r28,r5,25		/* vsid << 25 */
448	/* r0 = (va >> 12) & ((1ul << (40 - 12)) -1) */
449	rldicl	r0,r3,64-12,36
450	xor	r28,r28,r5		/* vsid ^ ( vsid << 25) */
451	xor	r28,r28,r0		/* hash */
452
453	/* Convert linux PTE bits into HW equivalents */
4544:
455#ifdef CONFIG_PPC_SUBPAGE_PROT
456	andc	r10,r30,r10
457	andi.	r3,r10,0x1fe		/* Get basic set of flags */
458	rlwinm	r0,r10,32-9+1,30,30	/* _PAGE_RW -> _PAGE_USER (r0) */
459#else
460	andi.	r3,r30,0x1fe		/* Get basic set of flags */
461	rlwinm	r0,r30,32-9+1,30,30	/* _PAGE_RW -> _PAGE_USER (r0) */
462#endif
463	xori	r3,r3,HPTE_R_N		/* _PAGE_EXEC -> NOEXEC */
464	rlwinm	r4,r30,32-7+1,30,30	/* _PAGE_DIRTY -> _PAGE_USER (r4) */
465	and	r0,r0,r4		/* _PAGE_RW & _PAGE_DIRTY ->r0 bit 30*/
466	andc	r0,r3,r0		/* r0 = pte & ~r0 */
467	rlwimi	r3,r0,32-1,31,31	/* Insert result into PP lsb */
468	/*
469	 * Always add "C" bit for perf. Memory coherence is always enabled
470	 */
471	ori	r3,r3,HPTE_R_C | HPTE_R_M
472
473	/* We eventually do the icache sync here (maybe inline that
474	 * code rather than call a C function...)
475	 */
476BEGIN_FTR_SECTION
477	mr	r4,r30
478	mr	r5,r7
479	bl	hash_page_do_lazy_icache
480END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE)
481
482	/* At this point, r3 contains new PP bits, save them in
483	 * place of "access" in the param area (sic)
484	 */
485	std	r3,STK_PARAM(R4)(r1)
486
487	/* Get htab_hash_mask */
488	ld	r4,htab_hash_mask@got(2)
489	ld	r27,0(r4)	/* htab_hash_mask -> r27 */
490
491	/* Check if we may already be in the hashtable, in this case, we
492	 * go to out-of-line code to try to modify the HPTE. We look for
493	 * the bit at (1 >> (index + 32))
494	 */
495	rldicl.	r0,r31,64-12,48
496	li	r26,0			/* Default hidx */
497	beq	htab_insert_pte
498
499	/*
500	 * Check if the pte was already inserted into the hash table
501	 * as a 64k HW page, and invalidate the 64k HPTE if so.
502	 */
503	andis.	r0,r31,_PAGE_COMBO@h
504	beq	htab_inval_old_hpte
505
506	ld	r6,STK_PARAM(R6)(r1)
507	ori	r26,r6,PTE_PAGE_HIDX_OFFSET /* Load the hidx mask. */
508	ld	r26,0(r26)
509	addi	r5,r25,36		/* Check actual HPTE_SUB bit, this */
510	rldcr.	r0,r31,r5,0		/* must match pgtable.h definition */
511	bne	htab_modify_pte
512
513htab_insert_pte:
514	/* real page number in r5, PTE RPN value + index */
515	andis.	r0,r31,_PAGE_4K_PFN@h
516	srdi	r5,r31,PTE_RPN_SHIFT
517	bne-	htab_special_pfn
518	sldi	r5,r5,PAGE_FACTOR
519	add	r5,r5,r25
520htab_special_pfn:
521	sldi	r5,r5,HW_PAGE_SHIFT
522
523	/* Calculate primary group hash */
524	and	r0,r28,r27
525	rldicr	r3,r0,3,63-3		/* r0 = (hash & mask) << 3 */
526
527	/* Call ppc_md.hpte_insert */
528	ld	r6,STK_PARAM(R4)(r1)	/* Retrieve new pp bits */
529	mr	r4,r29			/* Retrieve vpn */
530	li	r7,0			/* !bolted, !secondary */
531	li	r8,MMU_PAGE_4K		/* page size */
532	li	r9,MMU_PAGE_4K		/* actual page size */
533	ld	r10,STK_PARAM(R9)(r1)	/* segment size */
534.globl htab_call_hpte_insert1
535htab_call_hpte_insert1:
536	bl	.			/* patched by htab_finish_init() */
537	cmpdi	0,r3,0
538	bge	htab_pte_insert_ok	/* Insertion successful */
539	cmpdi	0,r3,-2			/* Critical failure */
540	beq-	htab_pte_insert_failure
541
542	/* Now try secondary slot */
543
544	/* real page number in r5, PTE RPN value + index */
545	andis.	r0,r31,_PAGE_4K_PFN@h
546	srdi	r5,r31,PTE_RPN_SHIFT
547	bne-	3f
548	sldi	r5,r5,PAGE_FACTOR
549	add	r5,r5,r25
5503:	sldi	r5,r5,HW_PAGE_SHIFT
551
552	/* Calculate secondary group hash */
553	andc	r0,r27,r28
554	rldicr	r3,r0,3,63-3		/* r0 = (~hash & mask) << 3 */
555
556	/* Call ppc_md.hpte_insert */
557	ld	r6,STK_PARAM(R4)(r1)	/* Retrieve new pp bits */
558	mr	r4,r29			/* Retrieve vpn */
559	li	r7,HPTE_V_SECONDARY	/* !bolted, secondary */
560	li	r8,MMU_PAGE_4K		/* page size */
561	li	r9,MMU_PAGE_4K		/* actual page size */
562	ld	r10,STK_PARAM(R9)(r1)	/* segment size */
563.globl htab_call_hpte_insert2
564htab_call_hpte_insert2:
565	bl	.			/* patched by htab_finish_init() */
566	cmpdi	0,r3,0
567	bge+	htab_pte_insert_ok	/* Insertion successful */
568	cmpdi	0,r3,-2			/* Critical failure */
569	beq-	htab_pte_insert_failure
570
571	/* Both are full, we need to evict something */
572	mftb	r0
573	/* Pick a random group based on TB */
574	andi.	r0,r0,1
575	mr	r5,r28
576	bne	2f
577	not	r5,r5
5782:	and	r0,r5,r27
579	rldicr	r3,r0,3,63-3		/* r0 = (hash & mask) << 3 */
580	/* Call ppc_md.hpte_remove */
581.globl htab_call_hpte_remove
582htab_call_hpte_remove:
583	bl	.			/* patched by htab_finish_init() */
584
585	/* Try all again */
586	b	htab_insert_pte
587
588	/*
589	 * Call out to C code to invalidate an 64k HW HPTE that is
590	 * useless now that the segment has been switched to 4k pages.
591	 */
592htab_inval_old_hpte:
593	mr	r3,r29			/* vpn */
594	mr	r4,r31			/* PTE.pte */
595	li	r5,0			/* PTE.hidx */
596	li	r6,MMU_PAGE_64K		/* psize */
597	ld	r7,STK_PARAM(R9)(r1)	/* ssize */
598	ld	r8,STK_PARAM(R8)(r1)	/* flags */
599	bl	flush_hash_page
600	/* Clear out _PAGE_HPTE_SUB bits in the new linux PTE */
601	lis	r0,_PAGE_HPTE_SUB@h
602	ori	r0,r0,_PAGE_HPTE_SUB@l
603	andc	r30,r30,r0
604	b	htab_insert_pte
605
606htab_bail_ok:
607	li	r3,0
608	b	htab_bail
609
610htab_pte_insert_ok:
611	/* Insert slot number & secondary bit in PTE second half,
612	 * clear _PAGE_BUSY and set approriate HPTE slot bit
613	 */
614	ld	r6,STK_PARAM(R6)(r1)
615	li	r0,_PAGE_BUSY
616	andc	r30,r30,r0
617	/* HPTE SUB bit */
618	li	r0,1
619	subfic	r5,r25,27		/* Must match bit position in */
620	sld	r0,r0,r5		/* pgtable.h */
621	or	r30,r30,r0
622	/* hindx */
623	sldi	r5,r25,2
624	sld	r3,r3,r5
625	li	r4,0xf
626	sld	r4,r4,r5
627	andc	r26,r26,r4
628	or	r26,r26,r3
629	ori	r5,r6,PTE_PAGE_HIDX_OFFSET
630	std	r26,0(r5)
631	lwsync
632	std	r30,0(r6)
633	li	r3, 0
634htab_bail:
635	ld	r25,STK_REG(R25)(r1)
636	ld	r26,STK_REG(R26)(r1)
637	ld	r27,STK_REG(R27)(r1)
638	ld	r28,STK_REG(R28)(r1)
639	ld	r29,STK_REG(R29)(r1)
640	ld      r30,STK_REG(R30)(r1)
641	ld      r31,STK_REG(R31)(r1)
642	addi    r1,r1,STACKFRAMESIZE
643	ld      r0,16(r1)
644	mtlr    r0
645	blr
646
647htab_modify_pte:
648	/* Keep PP bits in r4 and slot idx from the PTE around in r3 */
649	mr	r4,r3
650	sldi	r5,r25,2
651	srd	r3,r26,r5
652
653	/* Secondary group ? if yes, get a inverted hash value */
654	mr	r5,r28
655	andi.	r0,r3,0x8 /* page secondary ? */
656	beq	1f
657	not	r5,r5
6581:	andi.	r3,r3,0x7 /* extract idx alone */
659
660	/* Calculate proper slot value for ppc_md.hpte_updatepp */
661	and	r0,r5,r27
662	rldicr	r0,r0,3,63-3	/* r0 = (hash & mask) << 3 */
663	add	r3,r0,r3	/* add slot idx */
664
665	/* Call ppc_md.hpte_updatepp */
666	mr	r5,r29			/* vpn */
667	li	r6,MMU_PAGE_4K		/* base page size */
668	li	r7,MMU_PAGE_4K		/* actual page size */
669	ld	r8,STK_PARAM(R9)(r1)	/* segment size */
670	ld	r9,STK_PARAM(R8)(r1)	/* get "flags" param */
671.globl htab_call_hpte_updatepp
672htab_call_hpte_updatepp:
673	bl	.			/* patched by htab_finish_init() */
674
675	/* if we failed because typically the HPTE wasn't really here
676	 * we try an insertion.
677	 */
678	cmpdi	0,r3,-1
679	beq-	htab_insert_pte
680
681	/* Clear the BUSY bit and Write out the PTE */
682	li	r0,_PAGE_BUSY
683	andc	r30,r30,r0
684	ld	r6,STK_PARAM(R6)(r1)
685	std	r30,0(r6)
686	li	r3,0
687	b	htab_bail
688
689htab_wrong_access:
690	/* Bail out clearing reservation */
691	stdcx.	r31,0,r6
692	li	r3,1
693	b	htab_bail
694
695htab_pte_insert_failure:
696	/* Bail out restoring old PTE */
697	ld	r6,STK_PARAM(R6)(r1)
698	std	r31,0(r6)
699	li	r3,-1
700	b	htab_bail
701
702#endif /* CONFIG_PPC_64K_PAGES */
703
704#ifdef CONFIG_PPC_HAS_HASH_64K
705
706/*****************************************************************************
707 *                                                                           *
708 *           64K SW & 64K HW in a 64K segment pages implementation           *
709 *                                                                           *
710 *****************************************************************************/
711
712_GLOBAL(__hash_page_64K)
713	mflr	r0
714	std	r0,16(r1)
715	stdu	r1,-STACKFRAMESIZE(r1)
716	/* Save all params that we need after a function call */
717	std	r6,STK_PARAM(R6)(r1)
718	std	r8,STK_PARAM(R8)(r1)
719	std	r9,STK_PARAM(R9)(r1)
720
721	/* Save non-volatile registers.
722	 * r31 will hold "old PTE"
723	 * r30 is "new PTE"
724	 * r29 is vpn
725	 * r28 is a hash value
726	 * r27 is hashtab mask (maybe dynamic patched instead ?)
727	 */
728	std	r27,STK_REG(R27)(r1)
729	std	r28,STK_REG(R28)(r1)
730	std	r29,STK_REG(R29)(r1)
731	std	r30,STK_REG(R30)(r1)
732	std	r31,STK_REG(R31)(r1)
733
734	/* Step 1:
735	 *
736	 * Check permissions, atomically mark the linux PTE busy
737	 * and hashed.
738	 */
7391:
740	ldarx	r31,0,r6
741	/* Check access rights (access & ~(pte_val(*ptep))) */
742	andc.	r0,r4,r31
743	bne-	ht64_wrong_access
744	/* Check if PTE is busy */
745	andi.	r0,r31,_PAGE_BUSY
746	/* If so, just bail out and refault if needed. Someone else
747	 * is changing this PTE anyway and might hash it.
748	 */
749	bne-	ht64_bail_ok
750BEGIN_FTR_SECTION
751	/* Check if PTE has the cache-inhibit bit set */
752	andi.	r0,r31,_PAGE_NO_CACHE
753	/* If so, bail out and refault as a 4k page */
754	bne-	ht64_bail_ok
755END_MMU_FTR_SECTION_IFCLR(MMU_FTR_CI_LARGE_PAGE)
756	/* Prepare new PTE value (turn access RW into DIRTY, then
757	 * add BUSY and ACCESSED)
758	 */
759	rlwinm	r30,r4,32-9+7,31-7,31-7	/* _PAGE_RW -> _PAGE_DIRTY */
760	or	r30,r30,r31
761	ori	r30,r30,_PAGE_BUSY | _PAGE_ACCESSED
762	/* Write the linux PTE atomically (setting busy) */
763	stdcx.	r30,0,r6
764	bne-	1b
765	isync
766
767	/* Step 2:
768	 *
769	 * Insert/Update the HPTE in the hash table. At this point,
770	 * r4 (access) is re-useable, we use it for the new HPTE flags
771	 */
772
773BEGIN_FTR_SECTION
774	cmpdi	r9,0			/* check segment size */
775	bne	3f
776END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
777	/* Calc vpn and put it in r29 */
778	sldi	r29,r5,SID_SHIFT - VPN_SHIFT
779	rldicl  r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
780	or	r29,r28,r29
781
782	/* Calculate hash value for primary slot and store it in r28
783	 * r3 = va, r5 = vsid
784	 * r0 = (va >> 16) & ((1ul << (28 - 16)) -1)
785	 */
786	rldicl	r0,r3,64-16,52
787	xor	r28,r5,r0		/* hash */
788	b	4f
789
7903:	/* Calc vpn and put it in r29 */
791	sldi	r29,r5,SID_SHIFT_1T - VPN_SHIFT
792	rldicl  r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT_1T - VPN_SHIFT)
793	or	r29,r28,r29
794	/*
795	 * calculate hash value for primary slot and
796	 * store it in r28 for 1T segment
797	 * r3 = va, r5 = vsid
798	 */
799	sldi	r28,r5,25		/* vsid << 25 */
800	/* r0 = (va >> 16) & ((1ul << (40 - 16)) -1) */
801	rldicl	r0,r3,64-16,40
802	xor	r28,r28,r5		/* vsid ^ ( vsid << 25) */
803	xor	r28,r28,r0		/* hash */
804
805	/* Convert linux PTE bits into HW equivalents */
8064:	andi.	r3,r30,0x1fe		/* Get basic set of flags */
807	xori	r3,r3,HPTE_R_N		/* _PAGE_EXEC -> NOEXEC */
808	rlwinm	r0,r30,32-9+1,30,30	/* _PAGE_RW -> _PAGE_USER (r0) */
809	rlwinm	r4,r30,32-7+1,30,30	/* _PAGE_DIRTY -> _PAGE_USER (r4) */
810	and	r0,r0,r4		/* _PAGE_RW & _PAGE_DIRTY ->r0 bit 30*/
811	andc	r0,r30,r0		/* r0 = pte & ~r0 */
812	rlwimi	r3,r0,32-1,31,31	/* Insert result into PP lsb */
813	/*
814	 * Always add "C" bit for perf. Memory coherence is always enabled
815	 */
816	ori	r3,r3,HPTE_R_C | HPTE_R_M
817
818	/* We eventually do the icache sync here (maybe inline that
819	 * code rather than call a C function...)
820	 */
821BEGIN_FTR_SECTION
822	mr	r4,r30
823	mr	r5,r7
824	bl	hash_page_do_lazy_icache
825END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE)
826
827	/* At this point, r3 contains new PP bits, save them in
828	 * place of "access" in the param area (sic)
829	 */
830	std	r3,STK_PARAM(R4)(r1)
831
832	/* Get htab_hash_mask */
833	ld	r4,htab_hash_mask@got(2)
834	ld	r27,0(r4)	/* htab_hash_mask -> r27 */
835
836	/* Check if we may already be in the hashtable, in this case, we
837	 * go to out-of-line code to try to modify the HPTE
838	 */
839	rldicl.	r0,r31,64-12,48
840	bne	ht64_modify_pte
841
842ht64_insert_pte:
843	/* Clear hpte bits in new pte (we also clear BUSY btw) and
844	 * add _PAGE_HPTE_SUB0
845	 */
846	lis	r0,_PAGE_HPTEFLAGS@h
847	ori	r0,r0,_PAGE_HPTEFLAGS@l
848	andc	r30,r30,r0
849#ifdef CONFIG_PPC_64K_PAGES
850	oris	r30,r30,_PAGE_HPTE_SUB0@h
851#else
852	ori	r30,r30,_PAGE_HASHPTE
853#endif
854	/* Phyical address in r5 */
855	rldicl	r5,r31,64-PTE_RPN_SHIFT,PTE_RPN_SHIFT
856	sldi	r5,r5,PAGE_SHIFT
857
858	/* Calculate primary group hash */
859	and	r0,r28,r27
860	rldicr	r3,r0,3,63-3	/* r0 = (hash & mask) << 3 */
861
862	/* Call ppc_md.hpte_insert */
863	ld	r6,STK_PARAM(R4)(r1)	/* Retrieve new pp bits */
864	mr	r4,r29			/* Retrieve vpn */
865	li	r7,0			/* !bolted, !secondary */
866	li	r8,MMU_PAGE_64K
867	li	r9,MMU_PAGE_64K		/* actual page size */
868	ld	r10,STK_PARAM(R9)(r1)	/* segment size */
869.globl ht64_call_hpte_insert1
870ht64_call_hpte_insert1:
871	bl	.			/* patched by htab_finish_init() */
872	cmpdi	0,r3,0
873	bge	ht64_pte_insert_ok	/* Insertion successful */
874	cmpdi	0,r3,-2			/* Critical failure */
875	beq-	ht64_pte_insert_failure
876
877	/* Now try secondary slot */
878
879	/* Phyical address in r5 */
880	rldicl	r5,r31,64-PTE_RPN_SHIFT,PTE_RPN_SHIFT
881	sldi	r5,r5,PAGE_SHIFT
882
883	/* Calculate secondary group hash */
884	andc	r0,r27,r28
885	rldicr	r3,r0,3,63-3	/* r0 = (~hash & mask) << 3 */
886
887	/* Call ppc_md.hpte_insert */
888	ld	r6,STK_PARAM(R4)(r1)	/* Retrieve new pp bits */
889	mr	r4,r29			/* Retrieve vpn */
890	li	r7,HPTE_V_SECONDARY	/* !bolted, secondary */
891	li	r8,MMU_PAGE_64K
892	li	r9,MMU_PAGE_64K		/* actual page size */
893	ld	r10,STK_PARAM(R9)(r1)	/* segment size */
894.globl ht64_call_hpte_insert2
895ht64_call_hpte_insert2:
896	bl	.			/* patched by htab_finish_init() */
897	cmpdi	0,r3,0
898	bge+	ht64_pte_insert_ok	/* Insertion successful */
899	cmpdi	0,r3,-2			/* Critical failure */
900	beq-	ht64_pte_insert_failure
901
902	/* Both are full, we need to evict something */
903	mftb	r0
904	/* Pick a random group based on TB */
905	andi.	r0,r0,1
906	mr	r5,r28
907	bne	2f
908	not	r5,r5
9092:	and	r0,r5,r27
910	rldicr	r3,r0,3,63-3	/* r0 = (hash & mask) << 3 */
911	/* Call ppc_md.hpte_remove */
912.globl ht64_call_hpte_remove
913ht64_call_hpte_remove:
914	bl	.			/* patched by htab_finish_init() */
915
916	/* Try all again */
917	b	ht64_insert_pte
918
919ht64_bail_ok:
920	li	r3,0
921	b	ht64_bail
922
923ht64_pte_insert_ok:
924	/* Insert slot number & secondary bit in PTE */
925	rldimi	r30,r3,12,63-15
926
927	/* Write out the PTE with a normal write
928	 * (maybe add eieio may be good still ?)
929	 */
930ht64_write_out_pte:
931	ld	r6,STK_PARAM(R6)(r1)
932	std	r30,0(r6)
933	li	r3, 0
934ht64_bail:
935	ld	r27,STK_REG(R27)(r1)
936	ld	r28,STK_REG(R28)(r1)
937	ld	r29,STK_REG(R29)(r1)
938	ld      r30,STK_REG(R30)(r1)
939	ld      r31,STK_REG(R31)(r1)
940	addi    r1,r1,STACKFRAMESIZE
941	ld      r0,16(r1)
942	mtlr    r0
943	blr
944
945ht64_modify_pte:
946	/* Keep PP bits in r4 and slot idx from the PTE around in r3 */
947	mr	r4,r3
948	rlwinm	r3,r31,32-12,29,31
949
950	/* Secondary group ? if yes, get a inverted hash value */
951	mr	r5,r28
952	andi.	r0,r31,_PAGE_F_SECOND
953	beq	1f
954	not	r5,r5
9551:
956	/* Calculate proper slot value for ppc_md.hpte_updatepp */
957	and	r0,r5,r27
958	rldicr	r0,r0,3,63-3	/* r0 = (hash & mask) << 3 */
959	add	r3,r0,r3	/* add slot idx */
960
961	/* Call ppc_md.hpte_updatepp */
962	mr	r5,r29			/* vpn */
963	li	r6,MMU_PAGE_64K		/* base page size */
964	li	r7,MMU_PAGE_64K		/* actual page size */
965	ld	r8,STK_PARAM(R9)(r1)	/* segment size */
966	ld	r9,STK_PARAM(R8)(r1)	/* get "flags" param */
967.globl ht64_call_hpte_updatepp
968ht64_call_hpte_updatepp:
969	bl	.			/* patched by htab_finish_init() */
970
971	/* if we failed because typically the HPTE wasn't really here
972	 * we try an insertion.
973	 */
974	cmpdi	0,r3,-1
975	beq-	ht64_insert_pte
976
977	/* Clear the BUSY bit and Write out the PTE */
978	li	r0,_PAGE_BUSY
979	andc	r30,r30,r0
980	b	ht64_write_out_pte
981
982ht64_wrong_access:
983	/* Bail out clearing reservation */
984	stdcx.	r31,0,r6
985	li	r3,1
986	b	ht64_bail
987
988ht64_pte_insert_failure:
989	/* Bail out restoring old PTE */
990	ld	r6,STK_PARAM(R6)(r1)
991	std	r31,0(r6)
992	li	r3,-1
993	b	ht64_bail
994
995
996#endif /* CONFIG_PPC_HAS_HASH_64K */
997
998
999/*****************************************************************************
1000 *                                                                           *
1001 *           Huge pages implementation is in hugetlbpage.c                   *
1002 *                                                                           *
1003 *****************************************************************************/
1004