2 * native hashtable management.
4 * SMP scalability work:
5 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
15 #include <linux/spinlock.h>
16 #include <linux/bitops.h>
18 #include <linux/threads.h>
19 #include <linux/smp.h>
21 #include <asm/machdep.h>
23 #include <asm/mmu_context.h>
24 #include <asm/pgtable.h>
25 #include <asm/tlbflush.h>
27 #include <asm/cputable.h>
29 #include <asm/kexec.h>
30 #include <asm/ppc-opcode.h>
32 #include <misc/cxl-base.h>
35 #define DBG_LOW(fmt...) udbg_printf(fmt)
37 #define DBG_LOW(fmt...)
41 #define HPTE_LOCK_BIT 3
43 #define HPTE_LOCK_BIT (56+3)
46 DEFINE_RAW_SPINLOCK(native_tlbie_lock
);
48 static inline void __tlbie(unsigned long vpn
, int psize
, int apsize
, int ssize
)
55 * We need 14 to 65 bits of va for a tlibe of 4K page
56 * With vpn we ignore the lower VPN_SHIFT bits already.
57 * And top two bits are already ignored because we can
58 * only accomadate 76 bits in a 64 bit vpn with a VPN_SHIFT
61 va
= vpn
<< VPN_SHIFT
;
63 * clear top 16 bits of 64bit va, non SLS segment
64 * Older versions of the architecture (2.02 and earler) require the
65 * masking of the top 16 bits.
67 va
&= ~(0xffffULL
<< 48);
71 /* clear out bits after (52) [0....52.....63] */
72 va
&= ~((1ul << (64 - 52)) - 1);
74 sllp
= ((mmu_psize_defs
[apsize
].sllp
& SLB_VSID_L
) >> 6) |
75 ((mmu_psize_defs
[apsize
].sllp
& SLB_VSID_LP
) >> 4);
77 asm volatile(ASM_FTR_IFCLR("tlbie %0,0", PPC_TLBIE(%1,%0), %2)
78 : : "r" (va
), "r"(0), "i" (CPU_FTR_ARCH_206
)
82 /* We need 14 to 14 + i bits of va */
83 penc
= mmu_psize_defs
[psize
].penc
[apsize
];
84 va
&= ~((1ul << mmu_psize_defs
[apsize
].shift
) - 1);
89 * We don't need all the bits, but rest of the bits
90 * must be ignored by the processor.
91 * vpn cover upto 65 bits of va. (0...65) and we need
94 va
|= (vpn
& 0xfe); /* AVAL */
96 asm volatile(ASM_FTR_IFCLR("tlbie %0,1", PPC_TLBIE(%1,%0), %2)
97 : : "r" (va
), "r"(0), "i" (CPU_FTR_ARCH_206
)
103 static inline void __tlbiel(unsigned long vpn
, int psize
, int apsize
, int ssize
)
109 /* VPN_SHIFT can be atmost 12 */
110 va
= vpn
<< VPN_SHIFT
;
112 * clear top 16 bits of 64 bit va, non SLS segment
113 * Older versions of the architecture (2.02 and earler) require the
114 * masking of the top 16 bits.
116 va
&= ~(0xffffULL
<< 48);
120 /* clear out bits after(52) [0....52.....63] */
121 va
&= ~((1ul << (64 - 52)) - 1);
123 sllp
= ((mmu_psize_defs
[apsize
].sllp
& SLB_VSID_L
) >> 6) |
124 ((mmu_psize_defs
[apsize
].sllp
& SLB_VSID_LP
) >> 4);
126 asm volatile(".long 0x7c000224 | (%0 << 11) | (0 << 21)"
127 : : "r"(va
) : "memory");
130 /* We need 14 to 14 + i bits of va */
131 penc
= mmu_psize_defs
[psize
].penc
[apsize
];
132 va
&= ~((1ul << mmu_psize_defs
[apsize
].shift
) - 1);
137 * We don't need all the bits, but rest of the bits
138 * must be ignored by the processor.
139 * vpn cover upto 65 bits of va. (0...65) and we need
144 asm volatile(".long 0x7c000224 | (%0 << 11) | (1 << 21)"
145 : : "r"(va
) : "memory");
151 static inline void tlbie(unsigned long vpn
, int psize
, int apsize
,
152 int ssize
, int local
)
154 unsigned int use_local
;
155 int lock_tlbie
= !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE
);
157 use_local
= local
&& mmu_has_feature(MMU_FTR_TLBIEL
) && !cxl_ctx_in_use();
160 use_local
= mmu_psize_defs
[psize
].tlbiel
;
161 if (lock_tlbie
&& !use_local
)
162 raw_spin_lock(&native_tlbie_lock
);
163 asm volatile("ptesync": : :"memory");
165 __tlbiel(vpn
, psize
, apsize
, ssize
);
166 asm volatile("ptesync": : :"memory");
168 __tlbie(vpn
, psize
, apsize
, ssize
);
169 asm volatile("eieio; tlbsync; ptesync": : :"memory");
171 if (lock_tlbie
&& !use_local
)
172 raw_spin_unlock(&native_tlbie_lock
);
175 static inline void native_lock_hpte(struct hash_pte
*hptep
)
177 unsigned long *word
= (unsigned long *)&hptep
->v
;
180 if (!test_and_set_bit_lock(HPTE_LOCK_BIT
, word
))
182 while(test_bit(HPTE_LOCK_BIT
, word
))
187 static inline void native_unlock_hpte(struct hash_pte
*hptep
)
189 unsigned long *word
= (unsigned long *)&hptep
->v
;
191 clear_bit_unlock(HPTE_LOCK_BIT
, word
);
194 static long native_hpte_insert(unsigned long hpte_group
, unsigned long vpn
,
195 unsigned long pa
, unsigned long rflags
,
196 unsigned long vflags
, int psize
, int apsize
, int ssize
)
198 struct hash_pte
*hptep
= htab_address
+ hpte_group
;
199 unsigned long hpte_v
, hpte_r
;
202 if (!(vflags
& HPTE_V_BOLTED
)) {
203 DBG_LOW(" insert(group=%lx, vpn=%016lx, pa=%016lx,"
204 " rflags=%lx, vflags=%lx, psize=%d)\n",
205 hpte_group
, vpn
, pa
, rflags
, vflags
, psize
);
208 for (i
= 0; i
< HPTES_PER_GROUP
; i
++) {
209 if (! (be64_to_cpu(hptep
->v
) & HPTE_V_VALID
)) {
210 /* retry with lock held */
211 native_lock_hpte(hptep
);
212 if (! (be64_to_cpu(hptep
->v
) & HPTE_V_VALID
))
214 native_unlock_hpte(hptep
);
220 if (i
== HPTES_PER_GROUP
)
223 hpte_v
= hpte_encode_v(vpn
, psize
, apsize
, ssize
) | vflags
| HPTE_V_VALID
;
224 hpte_r
= hpte_encode_r(pa
, psize
, apsize
) | rflags
;
226 if (!(vflags
& HPTE_V_BOLTED
)) {
227 DBG_LOW(" i=%x hpte_v=%016lx, hpte_r=%016lx\n",
231 hptep
->r
= cpu_to_be64(hpte_r
);
232 /* Guarantee the second dword is visible before the valid bit */
235 * Now set the first dword including the valid bit
236 * NOTE: this also unlocks the hpte
238 hptep
->v
= cpu_to_be64(hpte_v
);
240 __asm__
__volatile__ ("ptesync" : : : "memory");
242 return i
| (!!(vflags
& HPTE_V_SECONDARY
) << 3);
245 static long native_hpte_remove(unsigned long hpte_group
)
247 struct hash_pte
*hptep
;
250 unsigned long hpte_v
;
252 DBG_LOW(" remove(group=%lx)\n", hpte_group
);
254 /* pick a random entry to start at */
255 slot_offset
= mftb() & 0x7;
257 for (i
= 0; i
< HPTES_PER_GROUP
; i
++) {
258 hptep
= htab_address
+ hpte_group
+ slot_offset
;
259 hpte_v
= be64_to_cpu(hptep
->v
);
261 if ((hpte_v
& HPTE_V_VALID
) && !(hpte_v
& HPTE_V_BOLTED
)) {
262 /* retry with lock held */
263 native_lock_hpte(hptep
);
264 hpte_v
= be64_to_cpu(hptep
->v
);
265 if ((hpte_v
& HPTE_V_VALID
)
266 && !(hpte_v
& HPTE_V_BOLTED
))
268 native_unlock_hpte(hptep
);
275 if (i
== HPTES_PER_GROUP
)
278 /* Invalidate the hpte. NOTE: this also unlocks it */
284 static long native_hpte_updatepp(unsigned long slot
, unsigned long newpp
,
285 unsigned long vpn
, int bpsize
,
286 int apsize
, int ssize
, unsigned long flags
)
288 struct hash_pte
*hptep
= htab_address
+ slot
;
289 unsigned long hpte_v
, want_v
;
290 int ret
= 0, local
= 0;
292 want_v
= hpte_encode_avpn(vpn
, bpsize
, ssize
);
294 DBG_LOW(" update(vpn=%016lx, avpnv=%016lx, group=%lx, newpp=%lx)",
295 vpn
, want_v
& HPTE_V_AVPN
, slot
, newpp
);
297 hpte_v
= be64_to_cpu(hptep
->v
);
299 * We need to invalidate the TLB always because hpte_remove doesn't do
300 * a tlb invalidate. If a hash bucket gets full, we "evict" a more/less
301 * random entry from it. When we do that we don't invalidate the TLB
302 * (hpte_remove) because we assume the old translation is still
303 * technically "valid".
305 if (!HPTE_V_COMPARE(hpte_v
, want_v
) || !(hpte_v
& HPTE_V_VALID
)) {
306 DBG_LOW(" -> miss\n");
309 native_lock_hpte(hptep
);
310 /* recheck with locks held */
311 hpte_v
= be64_to_cpu(hptep
->v
);
312 if (unlikely(!HPTE_V_COMPARE(hpte_v
, want_v
) ||
313 !(hpte_v
& HPTE_V_VALID
))) {
316 DBG_LOW(" -> hit\n");
317 /* Update the HPTE */
318 hptep
->r
= cpu_to_be64((be64_to_cpu(hptep
->r
) &
319 ~(HPTE_R_PP
| HPTE_R_N
)) |
320 (newpp
& (HPTE_R_PP
| HPTE_R_N
|
323 native_unlock_hpte(hptep
);
326 if (flags
& HPTE_LOCAL_UPDATE
)
329 * Ensure it is out of the tlb too if it is not a nohpte fault
331 if (!(flags
& HPTE_NOHPTE_UPDATE
))
332 tlbie(vpn
, bpsize
, apsize
, ssize
, local
);
337 static long native_hpte_find(unsigned long vpn
, int psize
, int ssize
)
339 struct hash_pte
*hptep
;
343 unsigned long want_v
, hpte_v
;
345 hash
= hpt_hash(vpn
, mmu_psize_defs
[psize
].shift
, ssize
);
346 want_v
= hpte_encode_avpn(vpn
, psize
, ssize
);
348 /* Bolted mappings are only ever in the primary group */
349 slot
= (hash
& htab_hash_mask
) * HPTES_PER_GROUP
;
350 for (i
= 0; i
< HPTES_PER_GROUP
; i
++) {
351 hptep
= htab_address
+ slot
;
352 hpte_v
= be64_to_cpu(hptep
->v
);
354 if (HPTE_V_COMPARE(hpte_v
, want_v
) && (hpte_v
& HPTE_V_VALID
))
364 * Update the page protection bits. Intended to be used to create
365 * guard pages for kernel data structures on pages which are bolted
366 * in the HPT. Assumes pages being operated on will not be stolen.
368 * No need to lock here because we should be the only user.
370 static void native_hpte_updateboltedpp(unsigned long newpp
, unsigned long ea
,
371 int psize
, int ssize
)
376 struct hash_pte
*hptep
;
378 vsid
= get_kernel_vsid(ea
, ssize
);
379 vpn
= hpt_vpn(ea
, vsid
, ssize
);
381 slot
= native_hpte_find(vpn
, psize
, ssize
);
383 panic("could not find page to bolt\n");
384 hptep
= htab_address
+ slot
;
386 /* Update the HPTE */
387 hptep
->r
= cpu_to_be64((be64_to_cpu(hptep
->r
) &
388 ~(HPTE_R_PP
| HPTE_R_N
)) |
389 (newpp
& (HPTE_R_PP
| HPTE_R_N
)));
391 * Ensure it is out of the tlb too. Bolted entries base and
392 * actual page size will be same.
394 tlbie(vpn
, psize
, psize
, ssize
, 0);
397 static void native_hpte_invalidate(unsigned long slot
, unsigned long vpn
,
398 int bpsize
, int apsize
, int ssize
, int local
)
400 struct hash_pte
*hptep
= htab_address
+ slot
;
401 unsigned long hpte_v
;
402 unsigned long want_v
;
405 local_irq_save(flags
);
407 DBG_LOW(" invalidate(vpn=%016lx, hash: %lx)\n", vpn
, slot
);
409 want_v
= hpte_encode_avpn(vpn
, bpsize
, ssize
);
410 native_lock_hpte(hptep
);
411 hpte_v
= be64_to_cpu(hptep
->v
);
414 * We need to invalidate the TLB always because hpte_remove doesn't do
415 * a tlb invalidate. If a hash bucket gets full, we "evict" a more/less
416 * random entry from it. When we do that we don't invalidate the TLB
417 * (hpte_remove) because we assume the old translation is still
418 * technically "valid".
420 if (!HPTE_V_COMPARE(hpte_v
, want_v
) || !(hpte_v
& HPTE_V_VALID
))
421 native_unlock_hpte(hptep
);
423 /* Invalidate the hpte. NOTE: this also unlocks it */
426 /* Invalidate the TLB */
427 tlbie(vpn
, bpsize
, apsize
, ssize
, local
);
429 local_irq_restore(flags
);
432 static void native_hugepage_invalidate(unsigned long vsid
,
434 unsigned char *hpte_slot_array
,
435 int psize
, int ssize
, int local
)
438 struct hash_pte
*hptep
;
439 int actual_psize
= MMU_PAGE_16M
;
440 unsigned int max_hpte_count
, valid
;
441 unsigned long flags
, s_addr
= addr
;
442 unsigned long hpte_v
, want_v
, shift
;
443 unsigned long hidx
, vpn
= 0, hash
, slot
;
445 shift
= mmu_psize_defs
[psize
].shift
;
446 max_hpte_count
= 1U << (PMD_SHIFT
- shift
);
448 local_irq_save(flags
);
449 for (i
= 0; i
< max_hpte_count
; i
++) {
450 valid
= hpte_valid(hpte_slot_array
, i
);
453 hidx
= hpte_hash_index(hpte_slot_array
, i
);
456 addr
= s_addr
+ (i
* (1ul << shift
));
457 vpn
= hpt_vpn(addr
, vsid
, ssize
);
458 hash
= hpt_hash(vpn
, shift
, ssize
);
459 if (hidx
& _PTEIDX_SECONDARY
)
462 slot
= (hash
& htab_hash_mask
) * HPTES_PER_GROUP
;
463 slot
+= hidx
& _PTEIDX_GROUP_IX
;
465 hptep
= htab_address
+ slot
;
466 want_v
= hpte_encode_avpn(vpn
, psize
, ssize
);
467 native_lock_hpte(hptep
);
468 hpte_v
= be64_to_cpu(hptep
->v
);
470 /* Even if we miss, we need to invalidate the TLB */
471 if (!HPTE_V_COMPARE(hpte_v
, want_v
) || !(hpte_v
& HPTE_V_VALID
))
472 native_unlock_hpte(hptep
);
474 /* Invalidate the hpte. NOTE: this also unlocks it */
477 * We need to do tlb invalidate for all the address, tlbie
478 * instruction compares entry_VA in tlb with the VA specified
481 tlbie(vpn
, psize
, actual_psize
, ssize
, local
);
483 local_irq_restore(flags
);
486 static inline int __hpte_actual_psize(unsigned int lp
, int psize
)
491 /* start from 1 ignoring MMU_PAGE_4K */
492 for (i
= 1; i
< MMU_PAGE_COUNT
; i
++) {
495 if (mmu_psize_defs
[psize
].penc
[i
] == -1)
498 * encoding bits per actual page size
499 * PTE LP actual page size
506 shift
= mmu_psize_defs
[i
].shift
- LP_SHIFT
;
509 mask
= (1 << shift
) - 1;
510 if ((lp
& mask
) == mmu_psize_defs
[psize
].penc
[i
])
516 static void hpte_decode(struct hash_pte
*hpte
, unsigned long slot
,
517 int *psize
, int *apsize
, int *ssize
, unsigned long *vpn
)
519 unsigned long avpn
, pteg
, vpi
;
520 unsigned long hpte_v
= be64_to_cpu(hpte
->v
);
521 unsigned long hpte_r
= be64_to_cpu(hpte
->r
);
522 unsigned long vsid
, seg_off
;
523 int size
, a_size
, shift
;
524 /* Look at the 8 bit LP value */
525 unsigned int lp
= (hpte_r
>> LP_SHIFT
) & ((1 << LP_BITS
) - 1);
527 if (!(hpte_v
& HPTE_V_LARGE
)) {
529 a_size
= MMU_PAGE_4K
;
531 for (size
= 0; size
< MMU_PAGE_COUNT
; size
++) {
533 /* valid entries have a shift value */
534 if (!mmu_psize_defs
[size
].shift
)
537 a_size
= __hpte_actual_psize(lp
, size
);
542 /* This works for all page sizes, and for 256M and 1T segments */
543 *ssize
= hpte_v
>> HPTE_V_SSIZE_SHIFT
;
544 shift
= mmu_psize_defs
[size
].shift
;
546 avpn
= (HPTE_V_AVPN_VAL(hpte_v
) & ~mmu_psize_defs
[size
].avpnm
);
547 pteg
= slot
/ HPTES_PER_GROUP
;
548 if (hpte_v
& HPTE_V_SECONDARY
)
552 case MMU_SEGSIZE_256M
:
553 /* We only have 28 - 23 bits of seg_off in avpn */
554 seg_off
= (avpn
& 0x1f) << 23;
556 /* We can find more bits from the pteg value */
558 vpi
= (vsid
^ pteg
) & htab_hash_mask
;
559 seg_off
|= vpi
<< shift
;
561 *vpn
= vsid
<< (SID_SHIFT
- VPN_SHIFT
) | seg_off
>> VPN_SHIFT
;
564 /* We only have 40 - 23 bits of seg_off in avpn */
565 seg_off
= (avpn
& 0x1ffff) << 23;
568 vpi
= (vsid
^ (vsid
<< 25) ^ pteg
) & htab_hash_mask
;
569 seg_off
|= vpi
<< shift
;
571 *vpn
= vsid
<< (SID_SHIFT_1T
- VPN_SHIFT
) | seg_off
>> VPN_SHIFT
;
581 * clear all mappings on kexec. All cpus are in real mode (or they will
582 * be when they isi), and we are the only one left. We rely on our kernel
583 * mapping being 0xC0's and the hardware ignoring those two real bits.
585 * This must be called with interrupts disabled.
587 * Taking the native_tlbie_lock is unsafe here due to the possibility of
588 * lockdep being on. On pre POWER5 hardware, not taking the lock could
589 * cause deadlock. POWER5 and newer not taking the lock is fine. This only
590 * gets called during boot before secondary CPUs have come up and during
591 * crashdump and all bets are off anyway.
593 * TODO: add batching support when enabled. remember, no dynamic memory here,
594 * athough there is the control page available...
596 static void native_hpte_clear(void)
598 unsigned long vpn
= 0;
599 unsigned long slot
, slots
;
600 struct hash_pte
*hptep
= htab_address
;
601 unsigned long hpte_v
;
602 unsigned long pteg_count
;
603 int psize
, apsize
, ssize
;
605 pteg_count
= htab_hash_mask
+ 1;
607 slots
= pteg_count
* HPTES_PER_GROUP
;
609 for (slot
= 0; slot
< slots
; slot
++, hptep
++) {
611 * we could lock the pte here, but we are the only cpu
612 * running, right? and for crash dump, we probably
613 * don't want to wait for a maybe bad cpu.
615 hpte_v
= be64_to_cpu(hptep
->v
);
618 * Call __tlbie() here rather than tlbie() since we can't take the
621 if (hpte_v
& HPTE_V_VALID
) {
622 hpte_decode(hptep
, slot
, &psize
, &apsize
, &ssize
, &vpn
);
624 __tlbie(vpn
, psize
, apsize
, ssize
);
628 asm volatile("eieio; tlbsync; ptesync":::"memory");
632 * Batched hash table flush, we batch the tlbie's to avoid taking/releasing
633 * the lock all the time
635 static void native_flush_hash_range(unsigned long number
, int local
)
638 unsigned long hash
, index
, hidx
, shift
, slot
;
639 struct hash_pte
*hptep
;
640 unsigned long hpte_v
;
641 unsigned long want_v
;
644 struct ppc64_tlb_batch
*batch
= this_cpu_ptr(&ppc64_tlb_batch
);
645 unsigned long psize
= batch
->psize
;
646 int ssize
= batch
->ssize
;
648 unsigned int use_local
;
650 use_local
= local
&& mmu_has_feature(MMU_FTR_TLBIEL
) &&
651 mmu_psize_defs
[psize
].tlbiel
&& !cxl_ctx_in_use();
653 local_irq_save(flags
);
655 for (i
= 0; i
< number
; i
++) {
659 pte_iterate_hashed_subpages(pte
, psize
, vpn
, index
, shift
) {
660 hash
= hpt_hash(vpn
, shift
, ssize
);
661 hidx
= __rpte_to_hidx(pte
, index
);
662 if (hidx
& _PTEIDX_SECONDARY
)
664 slot
= (hash
& htab_hash_mask
) * HPTES_PER_GROUP
;
665 slot
+= hidx
& _PTEIDX_GROUP_IX
;
666 hptep
= htab_address
+ slot
;
667 want_v
= hpte_encode_avpn(vpn
, psize
, ssize
);
668 native_lock_hpte(hptep
);
669 hpte_v
= be64_to_cpu(hptep
->v
);
670 if (!HPTE_V_COMPARE(hpte_v
, want_v
) ||
671 !(hpte_v
& HPTE_V_VALID
))
672 native_unlock_hpte(hptep
);
675 } pte_iterate_hashed_end();
679 asm volatile("ptesync":::"memory");
680 for (i
= 0; i
< number
; i
++) {
684 pte_iterate_hashed_subpages(pte
, psize
,
686 __tlbiel(vpn
, psize
, psize
, ssize
);
687 } pte_iterate_hashed_end();
689 asm volatile("ptesync":::"memory");
691 int lock_tlbie
= !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE
);
694 raw_spin_lock(&native_tlbie_lock
);
696 asm volatile("ptesync":::"memory");
697 for (i
= 0; i
< number
; i
++) {
701 pte_iterate_hashed_subpages(pte
, psize
,
703 __tlbie(vpn
, psize
, psize
, ssize
);
704 } pte_iterate_hashed_end();
706 asm volatile("eieio; tlbsync; ptesync":::"memory");
709 raw_spin_unlock(&native_tlbie_lock
);
712 local_irq_restore(flags
);
715 void __init
hpte_init_native(void)
717 ppc_md
.hpte_invalidate
= native_hpte_invalidate
;
718 ppc_md
.hpte_updatepp
= native_hpte_updatepp
;
719 ppc_md
.hpte_updateboltedpp
= native_hpte_updateboltedpp
;
720 ppc_md
.hpte_insert
= native_hpte_insert
;
721 ppc_md
.hpte_remove
= native_hpte_remove
;
722 ppc_md
.hpte_clear_all
= native_hpte_clear
;
723 ppc_md
.flush_hash_range
= native_flush_hash_range
;
724 ppc_md
.hugepage_invalidate
= native_hugepage_invalidate
;