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[TCP]: TCP_CONG_YEAH requires TCP_CONG_VEGAS
[linux-2.6/verdex.git] / arch / powerpc / mm / hash_native_64.c
blob4a20d890e2f45be63cba2ea465941407935d3b4b
1 /*
2 * native hashtable management.
3 *
4 * SMP scalability work:
5 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
6 *
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.
11 */
12
13 #undef DEBUG_LOW
14
15 #include <linux/spinlock.h>
16 #include <linux/bitops.h>
17 #include <linux/threads.h>
18 #include <linux/smp.h>
19
20 #include <asm/abs_addr.h>
21 #include <asm/machdep.h>
22 #include <asm/mmu.h>
23 #include <asm/mmu_context.h>
24 #include <asm/pgtable.h>
25 #include <asm/tlbflush.h>
26 #include <asm/tlb.h>
27 #include <asm/cputable.h>
28 #include <asm/udbg.h>
29 #include <asm/kexec.h>
30
31 #ifdef DEBUG_LOW
32 #define DBG_LOW(fmt...) udbg_printf(fmt)
33 #else
34 #define DBG_LOW(fmt...)
35 #endif
36
37 #define HPTE_LOCK_BIT 3
38
39 static DEFINE_SPINLOCK(native_tlbie_lock);
40
41 static inline void __tlbie(unsigned long va, unsigned int psize)
42 {
43 unsigned int penc;
44
45 /* clear top 16 bits, non SLS segment */
46 va &= ~(0xffffULL << 48);
47
48 switch (psize) {
49 case MMU_PAGE_4K:
50 va &= ~0xffful;
51 asm volatile("tlbie %0,0" : : "r" (va) : "memory");
52 break;
53 default:
54 penc = mmu_psize_defs[psize].penc;
55 va &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
56 va |= penc << 12;
57 asm volatile("tlbie %0,1" : : "r" (va) : "memory");
58 break;
59 }
60 }
61
62 static inline void __tlbiel(unsigned long va, unsigned int psize)
63 {
64 unsigned int penc;
65
66 /* clear top 16 bits, non SLS segment */
67 va &= ~(0xffffULL << 48);
68
69 switch (psize) {
70 case MMU_PAGE_4K:
71 va &= ~0xffful;
72 asm volatile(".long 0x7c000224 | (%0 << 11) | (0 << 21)"
73 : : "r"(va) : "memory");
74 break;
75 default:
76 penc = mmu_psize_defs[psize].penc;
77 va &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
78 va |= penc << 12;
79 asm volatile(".long 0x7c000224 | (%0 << 11) | (1 << 21)"
80 : : "r"(va) : "memory");
81 break;
82 }
83
84 }
85
86 static inline void tlbie(unsigned long va, int psize, int local)
87 {
88 unsigned int use_local = local && cpu_has_feature(CPU_FTR_TLBIEL);
89 int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE);
90
91 if (use_local)
92 use_local = mmu_psize_defs[psize].tlbiel;
93 if (lock_tlbie && !use_local)
94 spin_lock(&native_tlbie_lock);
95 asm volatile("ptesync": : :"memory");
96 if (use_local) {
97 __tlbiel(va, psize);
98 asm volatile("ptesync": : :"memory");
99 } else {
100 __tlbie(va, psize);
101 asm volatile("eieio; tlbsync; ptesync": : :"memory");
102 }
103 if (lock_tlbie && !use_local)
104 spin_unlock(&native_tlbie_lock);
105 }
106
107 static inline void native_lock_hpte(hpte_t *hptep)
108 {
109 unsigned long *word = &hptep->v;
110
111 while (1) {
112 if (!test_and_set_bit(HPTE_LOCK_BIT, word))
113 break;
114 while(test_bit(HPTE_LOCK_BIT, word))
115 cpu_relax();
116 }
117 }
118
119 static inline void native_unlock_hpte(hpte_t *hptep)
120 {
121 unsigned long *word = &hptep->v;
122
123 asm volatile("lwsync":::"memory");
124 clear_bit(HPTE_LOCK_BIT, word);
125 }
126
127 static long native_hpte_insert(unsigned long hpte_group, unsigned long va,
128 unsigned long pa, unsigned long rflags,
129 unsigned long vflags, int psize)
130 {
131 hpte_t *hptep = htab_address + hpte_group;
132 unsigned long hpte_v, hpte_r;
133 int i;
134
135 if (!(vflags & HPTE_V_BOLTED)) {
136 DBG_LOW(" insert(group=%lx, va=%016lx, pa=%016lx,"
137 " rflags=%lx, vflags=%lx, psize=%d)\n",
138 hpte_group, va, pa, rflags, vflags, psize);
139 }
140
141 for (i = 0; i < HPTES_PER_GROUP; i++) {
142 if (! (hptep->v & HPTE_V_VALID)) {
143 /* retry with lock held */
144 native_lock_hpte(hptep);
145 if (! (hptep->v & HPTE_V_VALID))
146 break;
147 native_unlock_hpte(hptep);
148 }
149
150 hptep++;
151 }
152
153 if (i == HPTES_PER_GROUP)
154 return -1;
155
156 hpte_v = hpte_encode_v(va, psize) | vflags | HPTE_V_VALID;
157 hpte_r = hpte_encode_r(pa, psize) | rflags;
158
159 if (!(vflags & HPTE_V_BOLTED)) {
160 DBG_LOW(" i=%x hpte_v=%016lx, hpte_r=%016lx\n",
161 i, hpte_v, hpte_r);
162 }
163
164 hptep->r = hpte_r;
165 /* Guarantee the second dword is visible before the valid bit */
166 __asm__ __volatile__ ("eieio" : : : "memory");
167 /*
168 * Now set the first dword including the valid bit
169 * NOTE: this also unlocks the hpte
170 */
171 hptep->v = hpte_v;
172
173 __asm__ __volatile__ ("ptesync" : : : "memory");
174
175 return i | (!!(vflags & HPTE_V_SECONDARY) << 3);
176 }
177
178 static long native_hpte_remove(unsigned long hpte_group)
179 {
180 hpte_t *hptep;
181 int i;
182 int slot_offset;
183 unsigned long hpte_v;
184
185 DBG_LOW(" remove(group=%lx)\n", hpte_group);
186
187 /* pick a random entry to start at */
188 slot_offset = mftb() & 0x7;
189
190 for (i = 0; i < HPTES_PER_GROUP; i++) {
191 hptep = htab_address + hpte_group + slot_offset;
192 hpte_v = hptep->v;
193
194 if ((hpte_v & HPTE_V_VALID) && !(hpte_v & HPTE_V_BOLTED)) {
195 /* retry with lock held */
196 native_lock_hpte(hptep);
197 hpte_v = hptep->v;
198 if ((hpte_v & HPTE_V_VALID)
199 && !(hpte_v & HPTE_V_BOLTED))
200 break;
201 native_unlock_hpte(hptep);
202 }
203
204 slot_offset++;
205 slot_offset &= 0x7;
206 }
207
208 if (i == HPTES_PER_GROUP)
209 return -1;
210
211 /* Invalidate the hpte. NOTE: this also unlocks it */
212 hptep->v = 0;
213
214 return i;
215 }
216
217 static long native_hpte_updatepp(unsigned long slot, unsigned long newpp,
218 unsigned long va, int psize, int local)
219 {
220 hpte_t *hptep = htab_address + slot;
221 unsigned long hpte_v, want_v;
222 int ret = 0;
223
224 want_v = hpte_encode_v(va, psize);
225
226 DBG_LOW(" update(va=%016lx, avpnv=%016lx, hash=%016lx, newpp=%x)",
227 va, want_v & HPTE_V_AVPN, slot, newpp);
228
229 native_lock_hpte(hptep);
230
231 hpte_v = hptep->v;
232
233 /* Even if we miss, we need to invalidate the TLB */
234 if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID)) {
235 DBG_LOW(" -> miss\n");
236 native_unlock_hpte(hptep);
237 ret = -1;
238 } else {
239 DBG_LOW(" -> hit\n");
240 /* Update the HPTE */
241 hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) |
242 (newpp & (HPTE_R_PP | HPTE_R_N | HPTE_R_C));
243 native_unlock_hpte(hptep);
244 }
245
246 /* Ensure it is out of the tlb too. */
247 tlbie(va, psize, local);
248
249 return ret;
250 }
251
252 static long native_hpte_find(unsigned long va, int psize)
253 {
254 hpte_t *hptep;
255 unsigned long hash;
256 unsigned long i, j;
257 long slot;
258 unsigned long want_v, hpte_v;
259
260 hash = hpt_hash(va, mmu_psize_defs[psize].shift);
261 want_v = hpte_encode_v(va, psize);
262
263 for (j = 0; j < 2; j++) {
264 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
265 for (i = 0; i < HPTES_PER_GROUP; i++) {
266 hptep = htab_address + slot;
267 hpte_v = hptep->v;
268
269 if (HPTE_V_COMPARE(hpte_v, want_v)
270 && (hpte_v & HPTE_V_VALID)
271 && ( !!(hpte_v & HPTE_V_SECONDARY) == j)) {
272 /* HPTE matches */
273 if (j)
274 slot = -slot;
275 return slot;
276 }
277 ++slot;
278 }
279 hash = ~hash;
280 }
281
282 return -1;
283 }
284
285 /*
286 * Update the page protection bits. Intended to be used to create
287 * guard pages for kernel data structures on pages which are bolted
288 * in the HPT. Assumes pages being operated on will not be stolen.
289 *
290 * No need to lock here because we should be the only user.
291 */
292 static void native_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
293 int psize)
294 {
295 unsigned long vsid, va;
296 long slot;
297 hpte_t *hptep;
298
299 vsid = get_kernel_vsid(ea);
300 va = (vsid << 28) | (ea & 0x0fffffff);
301
302 slot = native_hpte_find(va, psize);
303 if (slot == -1)
304 panic("could not find page to bolt\n");
305 hptep = htab_address + slot;
306
307 /* Update the HPTE */
308 hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) |
309 (newpp & (HPTE_R_PP | HPTE_R_N));
310
311 /* Ensure it is out of the tlb too. */
312 tlbie(va, psize, 0);
313 }
314
315 static void native_hpte_invalidate(unsigned long slot, unsigned long va,
316 int psize, int local)
317 {
318 hpte_t *hptep = htab_address + slot;
319 unsigned long hpte_v;
320 unsigned long want_v;
321 unsigned long flags;
322
323 local_irq_save(flags);
324
325 DBG_LOW(" invalidate(va=%016lx, hash: %x)\n", va, slot);
326
327 want_v = hpte_encode_v(va, psize);
328 native_lock_hpte(hptep);
329 hpte_v = hptep->v;
330
331 /* Even if we miss, we need to invalidate the TLB */
332 if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID))
333 native_unlock_hpte(hptep);
334 else
335 /* Invalidate the hpte. NOTE: this also unlocks it */
336 hptep->v = 0;
337
338 /* Invalidate the TLB */
339 tlbie(va, psize, local);
340
341 local_irq_restore(flags);
342 }
343
344 #define LP_SHIFT 12
345 #define LP_BITS 8
346 #define LP_MASK(i) ((0xFF >> (i)) << LP_SHIFT)
347
348 static void hpte_decode(hpte_t *hpte, unsigned long slot,
349 int *psize, unsigned long *va)
350 {
351 unsigned long hpte_r = hpte->r;
352 unsigned long hpte_v = hpte->v;
353 unsigned long avpn;
354 int i, size, shift, penc;
355
356 if (!(hpte_v & HPTE_V_LARGE))
357 size = MMU_PAGE_4K;
358 else {
359 for (i = 0; i < LP_BITS; i++) {
360 if ((hpte_r & LP_MASK(i+1)) == LP_MASK(i+1))
361 break;
362 }
363 penc = LP_MASK(i+1) >> LP_SHIFT;
364 for (size = 0; size < MMU_PAGE_COUNT; size++) {
365
366 /* 4K pages are not represented by LP */
367 if (size == MMU_PAGE_4K)
368 continue;
369
370 /* valid entries have a shift value */
371 if (!mmu_psize_defs[size].shift)
372 continue;
373
374 if (penc == mmu_psize_defs[size].penc)
375 break;
376 }
377 }
378
379 /* This works for all page sizes, and for 256M and 1T segments */
380 shift = mmu_psize_defs[size].shift;
381 avpn = (HPTE_V_AVPN_VAL(hpte_v) & ~mmu_psize_defs[size].avpnm) << 23;
382
383 if (shift < 23) {
384 unsigned long vpi, vsid, pteg;
385
386 pteg = slot / HPTES_PER_GROUP;
387 if (hpte_v & HPTE_V_SECONDARY)
388 pteg = ~pteg;
389 switch (hpte_v >> HPTE_V_SSIZE_SHIFT) {
390 case MMU_SEGSIZE_256M:
391 vpi = ((avpn >> 28) ^ pteg) & htab_hash_mask;
392 break;
393 case MMU_SEGSIZE_1T:
394 vsid = avpn >> 40;
395 vpi = (vsid ^ (vsid << 25) ^ pteg) & htab_hash_mask;
396 break;
397 default:
398 avpn = vpi = size = 0;
399 }
400 avpn |= (vpi << mmu_psize_defs[size].shift);
401 }
402
403 *va = avpn;
404 *psize = size;
405 }
406
407 /*
408 * clear all mappings on kexec. All cpus are in real mode (or they will
409 * be when they isi), and we are the only one left. We rely on our kernel
410 * mapping being 0xC0's and the hardware ignoring those two real bits.
411 *
412 * TODO: add batching support when enabled. remember, no dynamic memory here,
413 * athough there is the control page available...
414 */
415 static void native_hpte_clear(void)
416 {
417 unsigned long slot, slots, flags;
418 hpte_t *hptep = htab_address;
419 unsigned long hpte_v, va;
420 unsigned long pteg_count;
421 int psize;
422
423 pteg_count = htab_hash_mask + 1;
424
425 local_irq_save(flags);
426
427 /* we take the tlbie lock and hold it. Some hardware will
428 * deadlock if we try to tlbie from two processors at once.
429 */
430 spin_lock(&native_tlbie_lock);
431
432 slots = pteg_count * HPTES_PER_GROUP;
433
434 for (slot = 0; slot < slots; slot++, hptep++) {
435 /*
436 * we could lock the pte here, but we are the only cpu
437 * running, right? and for crash dump, we probably
438 * don't want to wait for a maybe bad cpu.
439 */
440 hpte_v = hptep->v;
441
442 /*
443 * Call __tlbie() here rather than tlbie() since we
444 * already hold the native_tlbie_lock.
445 */
446 if (hpte_v & HPTE_V_VALID) {
447 hpte_decode(hptep, slot, &psize, &va);
448 hptep->v = 0;
449 __tlbie(va, psize);
450 }
451 }
452
453 asm volatile("eieio; tlbsync; ptesync":::"memory");
454 spin_unlock(&native_tlbie_lock);
455 local_irq_restore(flags);
456 }
457
458 /*
459 * Batched hash table flush, we batch the tlbie's to avoid taking/releasing
460 * the lock all the time
461 */
462 static void native_flush_hash_range(unsigned long number, int local)
463 {
464 unsigned long va, hash, index, hidx, shift, slot;
465 hpte_t *hptep;
466 unsigned long hpte_v;
467 unsigned long want_v;
468 unsigned long flags;
469 real_pte_t pte;
470 struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
471 unsigned long psize = batch->psize;
472 int i;
473
474 local_irq_save(flags);
475
476 for (i = 0; i < number; i++) {
477 va = batch->vaddr[i];
478 pte = batch->pte[i];
479
480 pte_iterate_hashed_subpages(pte, psize, va, index, shift) {
481 hash = hpt_hash(va, shift);
482 hidx = __rpte_to_hidx(pte, index);
483 if (hidx & _PTEIDX_SECONDARY)
484 hash = ~hash;
485 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
486 slot += hidx & _PTEIDX_GROUP_IX;
487 hptep = htab_address + slot;
488 want_v = hpte_encode_v(va, psize);
489 native_lock_hpte(hptep);
490 hpte_v = hptep->v;
491 if (!HPTE_V_COMPARE(hpte_v, want_v) ||
492 !(hpte_v & HPTE_V_VALID))
493 native_unlock_hpte(hptep);
494 else
495 hptep->v = 0;
496 } pte_iterate_hashed_end();
497 }
498
499 if (cpu_has_feature(CPU_FTR_TLBIEL) &&
500 mmu_psize_defs[psize].tlbiel && local) {
501 asm volatile("ptesync":::"memory");
502 for (i = 0; i < number; i++) {
503 va = batch->vaddr[i];
504 pte = batch->pte[i];
505
506 pte_iterate_hashed_subpages(pte, psize, va, index,
507 shift) {
508 __tlbiel(va, psize);
509 } pte_iterate_hashed_end();
510 }
511 asm volatile("ptesync":::"memory");
512 } else {
513 int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE);
514
515 if (lock_tlbie)
516 spin_lock(&native_tlbie_lock);
517
518 asm volatile("ptesync":::"memory");
519 for (i = 0; i < number; i++) {
520 va = batch->vaddr[i];
521 pte = batch->pte[i];
522
523 pte_iterate_hashed_subpages(pte, psize, va, index,
524 shift) {
525 __tlbie(va, psize);
526 } pte_iterate_hashed_end();
527 }
528 asm volatile("eieio; tlbsync; ptesync":::"memory");
529
530 if (lock_tlbie)
531 spin_unlock(&native_tlbie_lock);
532 }
533
534 local_irq_restore(flags);
535 }
536
537 #ifdef CONFIG_PPC_PSERIES
538 /* Disable TLB batching on nighthawk */
539 static inline int tlb_batching_enabled(void)
540 {
541 struct device_node *root = of_find_node_by_path("/");
542 int enabled = 1;
543
544 if (root) {
545 const char *model = of_get_property(root, "model", NULL);
546 if (model && !strcmp(model, "IBM,9076-N81"))
547 enabled = 0;
548 of_node_put(root);
549 }
550
551 return enabled;
552 }
553 #else
554 static inline int tlb_batching_enabled(void)
555 {
556 return 1;
557 }
558 #endif
559
560 void __init hpte_init_native(void)
561 {
562 ppc_md.hpte_invalidate = native_hpte_invalidate;
563 ppc_md.hpte_updatepp = native_hpte_updatepp;
564 ppc_md.hpte_updateboltedpp = native_hpte_updateboltedpp;
565 ppc_md.hpte_insert = native_hpte_insert;
566 ppc_md.hpte_remove = native_hpte_remove;
567 ppc_md.hpte_clear_all = native_hpte_clear;
568 if (tlb_batching_enabled())
569 ppc_md.flush_hash_range = native_flush_hash_range;
570 }
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