1 /*        $NetBSD: pmap_tlb.c,v 1.62 2024/01/01 16:56:30 skrll Exp $  */
2 
3 /*-
4  * Copyright (c) 2010 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas at 3am Software Foundry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 
34 __KERNEL_RCSID(0, "$NetBSD: pmap_tlb.c,v 1.62 2024/01/01 16:56:30 skrll Exp $");
35 
36 /*
37  * Manages address spaces in a TLB.
38  *
39  * Normally there is a 1:1 mapping between a TLB and a CPU.  However, some
40  * implementations may share a TLB between multiple CPUs (really CPU thread
41  * contexts).  This requires the TLB abstraction to be separated from the
42  * CPU abstraction.  It also requires that the TLB be locked while doing
43  * TLB activities.
44  *
45  * For each TLB, we track the ASIDs in use in a bitmap and a list of pmaps
46  * that have a valid ASID.
47  *
48  * We allocate ASIDs in increasing order until we have exhausted the supply,
49  * then reinitialize the ASID space, and start allocating again at 1.  When
50  * allocating from the ASID bitmap, we skip any ASID who has a corresponding
51  * bit set in the ASID bitmap.  Eventually this causes the ASID bitmap to fill
52  * and, when completely filled, a reinitialization of the ASID space.
53  *
54  * To reinitialize the ASID space, the ASID bitmap is reset and then the ASIDs
55  * of non-kernel TLB entries get recorded in the ASID bitmap.  If the entries
56  * in TLB consume more than half of the ASID space, all ASIDs are invalidated,
57  * the ASID bitmap is recleared, and the list of pmaps is emptied.  Otherwise,
58  * (the normal case), any ASID present in the TLB (even those which are no
59  * longer used by a pmap) will remain active (allocated) and all other ASIDs
60  * will be freed.  If the size of the TLB is much smaller than the ASID space,
61  * this algorithm completely avoids TLB invalidation.
62  *
63  * For multiprocessors, we also have to deal TLB invalidation requests from
64  * other CPUs, some of which are dealt with the reinitialization of the ASID
65  * space.  Whereas above we keep the ASIDs of those pmaps which have active
66  * TLB entries, this type of reinitialization preserves the ASIDs of any
67  * "onproc" user pmap and all other ASIDs will be freed.  We must do this
68  * since we can't change the current ASID.
69  *
70  * Each pmap has two bitmaps: pm_active and pm_onproc.  Each bit in pm_active
71  * indicates whether that pmap has an allocated ASID for a CPU.  Each bit in
72  * pm_onproc indicates that the pmap's ASID is in use, i.e. a CPU has it in its
73  * "current ASID" field, e.g. the ASID field of the COP 0 register EntryHi for
74  * MIPS, or the ASID field of TTBR0 for AA64.  The bit number used in these
75  * bitmaps comes from the CPU's cpu_index().  Even though these bitmaps contain
76  * the bits for all CPUs, the bits that correspond to the bits belonging to
77  * the CPUs sharing a TLB can only be manipulated while holding that TLB's
78  * lock.  Atomic ops must be used to update them since multiple CPUs may be
79  * changing different sets of bits at same time but these sets never overlap.
80  *
81  * When a change to the local TLB may require a change in the TLB's of other
82  * CPUs, we try to avoid sending an IPI if at all possible.  For instance, if
83  * we are updating a PTE and that PTE previously was invalid and therefore
84  * couldn't support an active mapping, there's no need for an IPI since there
85  * can't be a TLB entry to invalidate.  The other case is when we change a PTE
86  * to be modified we just update the local TLB.  If another TLB has a stale
87  * entry, a TLB MOD exception will be raised and that will cause the local TLB
88  * to be updated.
89  *
90  * We never need to update a non-local TLB if the pmap doesn't have a valid
91  * ASID for that TLB.  If it does have a valid ASID but isn't current "onproc"
92  * we simply reset its ASID for that TLB and then when it goes "onproc" it
93  * will allocate a new ASID and any existing TLB entries will be orphaned.
94  * Only in the case that pmap has an "onproc" ASID do we actually have to send
95  * an IPI.
96  *
97  * Once we determined we must send an IPI to shootdown a TLB, we need to send
98  * it to one of CPUs that share that TLB.  We choose the lowest numbered CPU
99  * that has one of the pmap's ASID "onproc".  In reality, any CPU sharing that
100  * TLB would do, but interrupting an active CPU seems best.
101  *
102  * A TLB might have multiple shootdowns active concurrently.  The shootdown
103  * logic compresses these into a few cases:
104  *        0) nobody needs to have its TLB entries invalidated
105  *        1) one ASID needs to have its TLB entries invalidated
106  *        2) more than one ASID needs to have its TLB entries invalidated
107  *        3) the kernel needs to have its TLB entries invalidated
108  *        4) the kernel and one or more ASID need their TLB entries invalidated.
109  *
110  * And for each case we do:
111  *        0) nothing,
112  *        1) if that ASID is still "onproc", we invalidate the TLB entries for
113  *           that single ASID.  If not, just reset the pmap's ASID to invalidate
114  *           and let it allocate a new ASID the next time it goes "onproc",
115  *        2) we reinitialize the ASID space (preserving any "onproc" ASIDs) and
116  *           invalidate all non-wired non-global TLB entries,
117  *        3) we invalidate all of the non-wired global TLB entries,
118  *        4) we reinitialize the ASID space (again preserving any "onproc" ASIDs)
119  *           invalidate all non-wired TLB entries.
120  *
121  * As you can see, shootdowns are not concerned with addresses, just address
122  * spaces.  Since the number of TLB entries is usually quite small, this avoids
123  * a lot of overhead for not much gain.
124  */
125 
126 #define __PMAP_PRIVATE
127 
128 #include "opt_multiprocessor.h"
129 
130 #include <sys/param.h>
131 
132 #include <sys/atomic.h>
133 #include <sys/cpu.h>
134 #include <sys/kernel.h>                           /* for cold */
135 #include <sys/mutex.h>
136 #include <sys/proc.h>
137 #include <sys/systm.h>
138 
139 #include <uvm/uvm.h>
140 
141 static kmutex_t pmap_tlb0_lock __cacheline_aligned;
142 
143 #define   IFCONSTANT(x)       (__builtin_constant_p((x)) ? (x) : 0)
144 
145 #if KERNEL_PID > 31
146 #error "KERNEL_PID expected in range 0-31"
147 #endif
148 
149 #define   TLBINFO_ASID_MARK_UNUSED(ti, asid) \
150           __BITMAP_CLR((asid), &(ti)->ti_asid_bitmap)
151 #define   TLBINFO_ASID_MARK_USED(ti, asid) \
152           __BITMAP_SET((asid), &(ti)->ti_asid_bitmap)
153 #define   TLBINFO_ASID_INUSE_P(ti, asid) \
154           __BITMAP_ISSET((asid), &(ti)->ti_asid_bitmap)
155 #define   TLBINFO_ASID_RESET(ti) \
156           do {                                                                            \
157                     __BITMAP_ZERO(&ti->ti_asid_bitmap);                         \
158                     for (tlb_asid_t asid = 0; asid <= KERNEL_PID; asid++)       \
159                               TLBINFO_ASID_MARK_USED(ti, asid);                 \
160           } while (0)
161 #define   TLBINFO_ASID_INITIAL_FREE(asid_max) \
162           (asid_max + 1 /* 0 */ - (1 + KERNEL_PID))
163 
164 struct pmap_tlb_info pmap_tlb0_info = {
165           .ti_name = "tlb0",
166           .ti_asid_hint = KERNEL_PID + 1,
167 #ifdef PMAP_TLB_NUM_PIDS
168           .ti_asid_max = IFCONSTANT(PMAP_TLB_NUM_PIDS - 1),
169           .ti_asids_free = IFCONSTANT(
170                     TLBINFO_ASID_INITIAL_FREE(PMAP_TLB_NUM_PIDS - 1)),
171 #endif
172           .ti_asid_bitmap._b[0] = __BITS(0, KERNEL_PID),
173 #ifdef PMAP_TLB_WIRED_UPAGES
174           .ti_wired = PMAP_TLB_WIRED_UPAGES,
175 #endif
176           .ti_lock = &pmap_tlb0_lock,
177           .ti_pais = LIST_HEAD_INITIALIZER(pmap_tlb0_info.ti_pais),
178 #if defined(MULTIPROCESSOR) && PMAP_TLB_MAX > 1
179           .ti_tlbinvop = TLBINV_NOBODY,
180 #endif
181 };
182 
183 #undef IFCONSTANT
184 
185 #if defined(MULTIPROCESSOR) && PMAP_TLB_MAX > 1
186 struct pmap_tlb_info *pmap_tlbs[PMAP_TLB_MAX] = {
187           [0] = &pmap_tlb0_info,
188 };
189 u_int pmap_ntlbs = 1;
190 #endif
191 
192 #ifdef MULTIPROCESSOR
193 __unused static inline bool
pmap_tlb_intersecting_active_p(pmap_t pm,struct pmap_tlb_info * ti)194 pmap_tlb_intersecting_active_p(pmap_t pm, struct pmap_tlb_info *ti)
195 {
196 #if PMAP_TLB_MAX == 1
197           return !kcpuset_iszero(pm->pm_active);
198 #else
199           return kcpuset_intersecting_p(pm->pm_active, ti->ti_kcpuset);
200 #endif
201 }
202 
203 static inline bool
pmap_tlb_intersecting_onproc_p(pmap_t pm,struct pmap_tlb_info * ti)204 pmap_tlb_intersecting_onproc_p(pmap_t pm, struct pmap_tlb_info *ti)
205 {
206 #if PMAP_TLB_MAX == 1
207           return !kcpuset_iszero(pm->pm_onproc);
208 #else
209           return kcpuset_intersecting_p(pm->pm_onproc, ti->ti_kcpuset);
210 #endif
211 }
212 #endif
213 
214 static void
pmap_tlb_pai_check(struct pmap_tlb_info * ti,bool locked_p)215 pmap_tlb_pai_check(struct pmap_tlb_info *ti, bool locked_p)
216 {
217           UVMHIST_FUNC(__func__);
218           UVMHIST_CALLARGS(maphist, "(ti=%#jx)", (uintptr_t)ti, 0, 0, 0);
219 
220 #ifdef DIAGNOSTIC
221           struct pmap_asid_info *pai;
222           if (!locked_p)
223                     TLBINFO_LOCK(ti);
224           LIST_FOREACH(pai, &ti->ti_pais, pai_link) {
225                     KASSERT(pai != NULL);
226                     KASSERT(PAI_PMAP(pai, ti) != pmap_kernel());
227                     KASSERT(pai->pai_asid > KERNEL_PID);
228                     KASSERTMSG(pai->pai_asid <= ti->ti_asid_max,
229                         "pm %p asid %#x", PAI_PMAP(pai, ti), pai->pai_asid);
230                     KASSERTMSG(TLBINFO_ASID_INUSE_P(ti, pai->pai_asid),
231                         "pm %p asid %u", PAI_PMAP(pai, ti), pai->pai_asid);
232 #ifdef MULTIPROCESSOR
233                     KASSERT(pmap_tlb_intersecting_active_p(PAI_PMAP(pai, ti), ti));
234 #endif
235           }
236           if (!locked_p)
237                     TLBINFO_UNLOCK(ti);
238 #endif
239           UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
240 }
241 
242 static void
pmap_tlb_pai_reset(struct pmap_tlb_info * ti,struct pmap_asid_info * pai,struct pmap * pm)243 pmap_tlb_pai_reset(struct pmap_tlb_info *ti, struct pmap_asid_info *pai,
244           struct pmap *pm)
245 {
246           UVMHIST_FUNC(__func__);
247           UVMHIST_CALLARGS(maphist, "(ti=%#jx, pai=%#jx, pm=%#jx): asid %u",
248               (uintptr_t)ti, (uintptr_t)pai, (uintptr_t)pm, pai->pai_asid);
249 
250           /*
251            * We must have an ASID but it must not be onproc (on a processor).
252            */
253           KASSERT(pai->pai_asid > KERNEL_PID);
254           KASSERT(pai->pai_asid <= ti->ti_asid_max);
255 #if defined(MULTIPROCESSOR)
256           KASSERT(pmap_tlb_intersecting_active_p(pm, ti));
257           KASSERT(!pmap_tlb_intersecting_onproc_p(pm, ti));
258 #endif
259           LIST_REMOVE(pai, pai_link);
260 #ifdef DIAGNOSTIC
261           pai->pai_link.le_prev = NULL; /* tagged as unlinked */
262 #endif
263           /*
264            * If the platform has a cheap way to flush ASIDs then free the ASID
265            * back into the pool.  On multiprocessor systems, we will flush the
266            * ASID from the TLB when it's allocated.  That way we know the flush
267            * was always done in the correct TLB space.  On uniprocessor systems,
268            * just do the flush now since we know that it has been used.  This has
269            * a bit less overhead.  Either way, this will mean that we will only
270            * need to flush all ASIDs if all ASIDs are in use and we need to
271            * allocate a new one.
272            */
273           if (PMAP_TLB_FLUSH_ASID_ON_RESET) {
274 #ifndef MULTIPROCESSOR
275                     UVMHIST_LOG(maphist, " ... asid %u flushed", pai->pai_asid, 0,
276                         0, 0);
277                     tlb_invalidate_asids(pai->pai_asid, pai->pai_asid);
278 #endif
279                     if (TLBINFO_ASID_INUSE_P(ti, pai->pai_asid)) {
280                               UVMHIST_LOG(maphist, " ... asid marked unused",
281                                   pai->pai_asid, 0, 0, 0);
282                               TLBINFO_ASID_MARK_UNUSED(ti, pai->pai_asid);
283                               ti->ti_asids_free++;
284                     }
285           }
286           /*
287            * Note that we don't mark the ASID as not in use in the TLB's ASID
288            * bitmap (thus it can't be allocated until the ASID space is exhausted
289            * and therefore reinitialized).  We don't want to flush the TLB for
290            * entries belonging to this ASID so we will let natural TLB entry
291            * replacement flush them out of the TLB.  Any new entries for this
292            * pmap will need a new ASID allocated.
293            */
294           pai->pai_asid = 0;
295 
296 #if defined(MULTIPROCESSOR)
297           /*
298            * The bits in pm_active belonging to this TLB can only be changed
299            * while this TLB's lock is held.
300            */
301 #if PMAP_TLB_MAX == 1
302           kcpuset_zero(pm->pm_active);
303 #else
304           kcpuset_remove(pm->pm_active, ti->ti_kcpuset);
305 #endif
306           KASSERT(!pmap_tlb_intersecting_active_p(pm, ti));
307 #endif /* MULTIPROCESSOR */
308 
309           UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
310 }
311 
312 void
pmap_tlb_info_evcnt_attach(struct pmap_tlb_info * ti)313 pmap_tlb_info_evcnt_attach(struct pmap_tlb_info *ti)
314 {
315 #if defined(MULTIPROCESSOR) && !defined(PMAP_TLB_NO_SYNCI_EVCNT)
316           evcnt_attach_dynamic_nozero(&ti->ti_evcnt_synci_desired,
317               EVCNT_TYPE_MISC, NULL,
318               ti->ti_name, "icache syncs desired");
319           evcnt_attach_dynamic_nozero(&ti->ti_evcnt_synci_asts,
320               EVCNT_TYPE_MISC, &ti->ti_evcnt_synci_desired,
321               ti->ti_name, "icache sync asts");
322           evcnt_attach_dynamic_nozero(&ti->ti_evcnt_synci_all,
323               EVCNT_TYPE_MISC, &ti->ti_evcnt_synci_asts,
324               ti->ti_name, "icache full syncs");
325           evcnt_attach_dynamic_nozero(&ti->ti_evcnt_synci_pages,
326               EVCNT_TYPE_MISC, &ti->ti_evcnt_synci_asts,
327               ti->ti_name, "icache pages synced");
328           evcnt_attach_dynamic_nozero(&ti->ti_evcnt_synci_duplicate,
329               EVCNT_TYPE_MISC, &ti->ti_evcnt_synci_desired,
330               ti->ti_name, "icache dup pages skipped");
331           evcnt_attach_dynamic_nozero(&ti->ti_evcnt_synci_deferred,
332               EVCNT_TYPE_MISC, &ti->ti_evcnt_synci_desired,
333               ti->ti_name, "icache pages deferred");
334 #endif /* MULTIPROCESSOR && !PMAP_TLB_NO_SYNCI_EVCNT */
335           evcnt_attach_dynamic_nozero(&ti->ti_evcnt_asid_reinits,
336               EVCNT_TYPE_MISC, NULL,
337               ti->ti_name, "asid pool reinit");
338 }
339 
340 void
pmap_tlb_info_init(struct pmap_tlb_info * ti)341 pmap_tlb_info_init(struct pmap_tlb_info *ti)
342 {
343 #if defined(MULTIPROCESSOR)
344 #if PMAP_TLB_MAX == 1
345           KASSERT(ti == &pmap_tlb0_info);
346 #else
347           if (ti != &pmap_tlb0_info) {
348                     KASSERT(pmap_ntlbs < PMAP_TLB_MAX);
349 
350                     KASSERT(pmap_tlbs[pmap_ntlbs] == NULL);
351 
352                     ti->ti_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SCHED);
353                     TLBINFO_ASID_RESET(ti);
354                     ti->ti_asid_hint = KERNEL_PID + 1;
355                     ti->ti_asid_max = pmap_tlbs[0]->ti_asid_max;
356                     ti->ti_asids_free = TLBINFO_ASID_INITIAL_FREE(ti->ti_asid_max);
357                     ti->ti_tlbinvop = TLBINV_NOBODY;
358                     ti->ti_victim = NULL;
359                     kcpuset_create(&ti->ti_kcpuset, true);
360                     ti->ti_index = pmap_ntlbs++;
361                     ti->ti_wired = 0;
362                     pmap_tlbs[ti->ti_index] = ti;
363                     snprintf(ti->ti_name, sizeof(ti->ti_name), "tlb%u",
364                         ti->ti_index);
365                     pmap_tlb_info_evcnt_attach(ti);
366 
367                     KASSERT(ti->ti_asid_max < PMAP_TLB_BITMAP_LENGTH);
368                     return;
369           }
370 #endif
371 #endif /* MULTIPROCESSOR */
372           KASSERT(ti == &pmap_tlb0_info);
373           KASSERT(ti->ti_lock == &pmap_tlb0_lock);
374 
375           mutex_init(ti->ti_lock, MUTEX_DEFAULT, IPL_SCHED);
376 #if defined(MULTIPROCESSOR) && PMAP_TLB_MAX > 1
377           kcpuset_create(&ti->ti_kcpuset, true);
378           kcpuset_set(ti->ti_kcpuset, cpu_index(curcpu()));
379 #endif
380 
381           const tlb_asid_t asid_max = pmap_md_tlb_asid_max();
382           if (ti->ti_asid_max == 0 || asid_max < ti->ti_asid_max) {
383                     ti->ti_asid_max = asid_max;
384                     ti->ti_asids_free = TLBINFO_ASID_INITIAL_FREE(ti->ti_asid_max);
385           }
386 
387           KASSERT(__type_fit(tlb_asid_t, ti->ti_asid_max + 1));
388           KASSERT(ti->ti_asid_max < PMAP_TLB_BITMAP_LENGTH);
389 }
390 
391 #if defined(MULTIPROCESSOR)
392 void
pmap_tlb_info_attach(struct pmap_tlb_info * ti,struct cpu_info * ci)393 pmap_tlb_info_attach(struct pmap_tlb_info *ti, struct cpu_info *ci)
394 {
395           KASSERT(!CPU_IS_PRIMARY(ci));
396           KASSERT(ci->ci_data.cpu_idlelwp != NULL);
397           KASSERT(cold);
398 
399           TLBINFO_LOCK(ti);
400 #if PMAP_TLB_MAX > 1
401           kcpuset_set(ti->ti_kcpuset, cpu_index(ci));
402           cpu_set_tlb_info(ci, ti);
403 #endif
404 
405           /*
406            * Do any MD tlb info init.
407            */
408           pmap_md_tlb_info_attach(ti, ci);
409 
410           /*
411            * The kernel pmap uses the kcpuset_running set so it's always
412            * up-to-date.
413            */
414           TLBINFO_UNLOCK(ti);
415 }
416 #endif /* MULTIPROCESSOR */
417 
418 #ifdef DIAGNOSTIC
419 static size_t
pmap_tlb_asid_count(struct pmap_tlb_info * ti)420 pmap_tlb_asid_count(struct pmap_tlb_info *ti)
421 {
422           size_t count = 0;
423           for (tlb_asid_t asid = 1; asid <= ti->ti_asid_max; asid++) {
424                     if (TLBINFO_ASID_INUSE_P(ti, asid))
425                               count++;
426           }
427           return count;
428 }
429 #endif
430 
431 static void
pmap_tlb_asid_reinitialize(struct pmap_tlb_info * ti,enum tlb_invalidate_op op)432 pmap_tlb_asid_reinitialize(struct pmap_tlb_info *ti, enum tlb_invalidate_op op)
433 {
434           UVMHIST_FUNC(__func__);
435           UVMHIST_CALLARGS(maphist, "(ti=%#jx, op=%ju)", (uintptr_t)ti, op, 0, 0);
436 
437           pmap_tlb_pai_check(ti, true);
438 
439           ti->ti_evcnt_asid_reinits.ev_count++;
440 
441           /*
442            * First, clear the ASID bitmap (except for ASID 0 which belongs
443            * to the kernel).
444            */
445           ti->ti_asids_free = TLBINFO_ASID_INITIAL_FREE(ti->ti_asid_max);
446           ti->ti_asid_hint = KERNEL_PID + 1;
447           TLBINFO_ASID_RESET(ti);
448 
449           switch (op) {
450 #if defined(MULTIPROCESSOR) && defined(PMAP_TLB_NEED_SHOOTDOWN)
451           case TLBINV_ALL:
452                     tlb_invalidate_all();
453                     break;
454           case TLBINV_ALLUSER:
455                     tlb_invalidate_asids(KERNEL_PID + 1, ti->ti_asid_max);
456                     break;
457 #endif /* MULTIPROCESSOR && PMAP_TLB_NEED_SHOOTDOWN */
458           case TLBINV_NOBODY: {
459                     /*
460                      * If we are just reclaiming ASIDs in the TLB, let's go find
461                      * what ASIDs are in use in the TLB.  Since this is a
462                      * semi-expensive operation, we don't want to do it too often.
463                      * So if more half of the ASIDs are in use, we don't have
464                      * enough free ASIDs so invalidate the TLB entries with ASIDs
465                      * and clear the ASID bitmap.  That will force everyone to
466                      * allocate a new ASID.
467                      */
468 #if !defined(MULTIPROCESSOR) || defined(PMAP_TLB_NEED_SHOOTDOWN)
469                     pmap_tlb_asid_check();
470                     const u_int asids_found = tlb_record_asids(
471                         ti->ti_asid_bitmap._b, ti->ti_asid_max);
472                     pmap_tlb_asid_check();
473 #ifdef DIAGNOSTIC
474                     const u_int asids_count = pmap_tlb_asid_count(ti);
475                     KASSERTMSG(asids_found == asids_count,
476                         "found %u != count %u", asids_found, asids_count);
477 #endif
478                     if (__predict_false(asids_found >= ti->ti_asid_max / 2)) {
479                               tlb_invalidate_asids(KERNEL_PID + 1, ti->ti_asid_max);
480 #else /* MULTIPROCESSOR && !PMAP_TLB_NEED_SHOOTDOWN */
481                               /*
482                                * For those systems (PowerPC) that don't require
483                                * cross cpu TLB shootdowns, we have to invalidate the
484                                * entire TLB because we can't record the ASIDs in use
485                                * on the other CPUs.  This is hopefully cheaper than
486                                * than trying to use an IPI to record all the ASIDs
487                                * on all the CPUs (which would be a synchronization
488                                * nightmare).
489                                */
490                               tlb_invalidate_all();
491 #endif /* MULTIPROCESSOR && !PMAP_TLB_NEED_SHOOTDOWN */
492                               TLBINFO_ASID_RESET(ti);
493                               ti->ti_asids_free = TLBINFO_ASID_INITIAL_FREE(
494                                         ti->ti_asid_max);
495 #if !defined(MULTIPROCESSOR) || defined(PMAP_TLB_NEED_SHOOTDOWN)
496                     } else {
497                               ti->ti_asids_free -= asids_found;
498                     }
499 #endif /* !MULTIPROCESSOR || PMAP_TLB_NEED_SHOOTDOWN */
500                     KASSERTMSG(ti->ti_asids_free <= ti->ti_asid_max, "%u",
501                         ti->ti_asids_free);
502                     break;
503           }
504           default:
505                     panic("%s: unexpected op %d", __func__, op);
506           }
507 
508           /*
509            * Now go through the active ASIDs.  If the ASID is on a processor or
510            * we aren't invalidating all ASIDs and the TLB has an entry owned by
511            * that ASID, mark it as in use.  Otherwise release the ASID.
512            */
513           struct pmap_asid_info *pai, *next;
514           for (pai = LIST_FIRST(&ti->ti_pais); pai != NULL; pai = next) {
515                     struct pmap * const pm = PAI_PMAP(pai, ti);
516                     next = LIST_NEXT(pai, pai_link);
517                     KASSERT(pm != pmap_kernel());
518                     KASSERT(pai->pai_asid > KERNEL_PID);
519 #if defined(MULTIPROCESSOR)
520                     if (pmap_tlb_intersecting_onproc_p(pm, ti)) {
521                               if (!TLBINFO_ASID_INUSE_P(ti, pai->pai_asid)) {
522                                         TLBINFO_ASID_MARK_USED(ti, pai->pai_asid);
523                                         ti->ti_asids_free--;
524                               }
525                               continue;
526                     }
527 #endif /* MULTIPROCESSOR */
528                     if (TLBINFO_ASID_INUSE_P(ti, pai->pai_asid)) {
529                               KASSERT(op == TLBINV_NOBODY);
530                     } else {
531                               pmap_tlb_pai_reset(ti, pai, pm);
532                     }
533           }
534 #ifdef DIAGNOSTIC
535           size_t free_count __diagused = ti->ti_asid_max - pmap_tlb_asid_count(ti);
536           KASSERTMSG(free_count == ti->ti_asids_free,
537               "bitmap error: %zu != %u", free_count, ti->ti_asids_free);
538 #endif
539           UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
540 }
541 
542 #if defined(MULTIPROCESSOR) && defined(PMAP_TLB_NEED_SHOOTDOWN)
543 #if PMAP_TLB_MAX == 1
544 #error shootdown not required for single TLB systems
545 #endif
546 void
pmap_tlb_shootdown_process(void)547 pmap_tlb_shootdown_process(void)
548 {
549           struct cpu_info * const ci = curcpu();
550           struct pmap_tlb_info * const ti = cpu_tlb_info(ci);
551 
552           UVMHIST_FUNC(__func__);
553           UVMHIST_CALLED(maphist);
554 
555           KASSERT(cpu_intr_p());
556           KASSERTMSG(ci->ci_cpl >= IPL_SCHED, "%s: cpl (%d) < IPL_SCHED (%d)",
557               __func__, ci->ci_cpl, IPL_SCHED);
558 
559           TLBINFO_LOCK(ti);
560           UVMHIST_LOG(maphist, "ti %#jx", (uintptr_t)ti, 0, 0, 0);
561 
562           switch (ti->ti_tlbinvop) {
563           case TLBINV_ONE: {
564                     /*
565                      * We only need to invalidate one user ASID.
566                      */
567                     UVMHIST_LOG(maphist, "TLBINV_ONE ti->ti_victim %#jx", (uintptr_t)ti->ti_victim, 0, 0, 0);
568                     struct pmap_asid_info * const pai = PMAP_PAI(ti->ti_victim, ti);
569                     KASSERT(ti->ti_victim != pmap_kernel());
570                     if (pmap_tlb_intersecting_onproc_p(ti->ti_victim, ti)) {
571                               UVMHIST_LOG(maphist, "... onproc asid %jd", pai->pai_asid, 0, 0, 0);
572                               /*
573                                * The victim is an active pmap so we will just
574                                * invalidate its TLB entries.
575                                */
576                               KASSERT(pai->pai_asid > KERNEL_PID);
577                               pmap_tlb_asid_check();
578                               tlb_invalidate_asids(pai->pai_asid, pai->pai_asid);
579                               pmap_tlb_asid_check();
580                     } else if (pai->pai_asid) {
581                               UVMHIST_LOG(maphist, "... not active asid %jd", pai->pai_asid, 0, 0, 0);
582                               /*
583                                * The victim is no longer an active pmap for this TLB.
584                                * So simply clear its ASID and when pmap_activate is
585                                * next called for this pmap, it will allocate a new
586                                * ASID.
587                                */
588                               pmap_tlb_pai_reset(ti, pai, PAI_PMAP(pai, ti));
589                     }
590                     break;
591           }
592           case TLBINV_ALLUSER:
593                     /*
594                      * Flush all user TLB entries.
595                      */
596                     pmap_tlb_asid_reinitialize(ti, TLBINV_ALLUSER);
597                     break;
598           case TLBINV_ALLKERNEL:
599                     /*
600                      * We need to invalidate all global TLB entries.
601                      */
602                     pmap_tlb_asid_check();
603                     tlb_invalidate_globals();
604                     pmap_tlb_asid_check();
605                     break;
606           case TLBINV_ALL:
607                     /*
608                      * Flush all the TLB entries (user and kernel).
609                      */
610                     pmap_tlb_asid_reinitialize(ti, TLBINV_ALL);
611                     break;
612           case TLBINV_NOBODY:
613                     /*
614                      * Might be spurious or another SMT CPU sharing this TLB
615                      * could have already done the work.
616                      */
617                     break;
618           }
619 
620           /*
621            * Indicate we are done with shutdown event.
622            */
623           ti->ti_victim = NULL;
624           ti->ti_tlbinvop = TLBINV_NOBODY;
625           TLBINFO_UNLOCK(ti);
626 }
627 
628 /*
629  * This state machine could be encoded into an array of integers but since all
630  * the values fit in 3 bits, the 5 entry "table" fits in a 16 bit value which
631  * can be loaded in a single instruction.
632  */
633 #define   TLBINV_MAP(op, nobody, one, alluser, allkernel, all)        \
634           ((((   (nobody) << 3 * TLBINV_NOBODY)                       \
635            | (      (one) << 3 * TLBINV_ONE)                          \
636            | (  (alluser) << 3 * TLBINV_ALLUSER)                      \
637            | ((allkernel) << 3 * TLBINV_ALLKERNEL)                    \
638            | (      (all) << 3 * TLBINV_ALL)) >> 3 * (op)) & 7)
639 
640 #define   TLBINV_USER_MAP(op) \
641           TLBINV_MAP(op, TLBINV_ONE, TLBINV_ALLUSER, TLBINV_ALLUSER,  \
642               TLBINV_ALL, TLBINV_ALL)
643 
644 #define   TLBINV_KERNEL_MAP(op)         \
645           TLBINV_MAP(op, TLBINV_ALLKERNEL, TLBINV_ALL, TLBINV_ALL,    \
646               TLBINV_ALLKERNEL, TLBINV_ALL)
647 
648 bool
pmap_tlb_shootdown_bystanders(pmap_t pm)649 pmap_tlb_shootdown_bystanders(pmap_t pm)
650 {
651           /*
652            * We don't need to deal with our own TLB.
653            */
654 
655           UVMHIST_FUNC(__func__);
656           UVMHIST_CALLARGS(maphist, "pm %#jx", (uintptr_t)pm, 0, 0, 0);
657 
658           KASSERT(kpreempt_disabled());
659 
660           const struct cpu_info * const ci = curcpu();
661 
662           kcpuset_t *pm_active = ci->ci_shootdowncpus;
663           kcpuset_copy(pm_active, pm->pm_active);
664           kcpuset_remove(pm_active, cpu_tlb_info(curcpu())->ti_kcpuset);
665           const bool kernel_p = (pm == pmap_kernel());
666           bool ipi_sent = false;
667 
668           /*
669            * If pm_active gets more bits set, then it's after all our changes
670            * have been made so they will already be cognizant of them.
671            */
672 
673           for (size_t i = 0; !kcpuset_iszero(pm_active); i++) {
674                     KASSERT(i < pmap_ntlbs);
675                     struct pmap_tlb_info * const ti = pmap_tlbs[i];
676                     KASSERT(tlbinfo_index(ti) == i);
677                     UVMHIST_LOG(maphist, "ti %#jx", (uintptr_t)ti, 0, 0, 0);
678                     /*
679                      * Skip this TLB if there are no active mappings for it.
680                      */
681                     if (!kcpuset_intersecting_p(pm_active, ti->ti_kcpuset))
682                               continue;
683                     struct pmap_asid_info * const pai = PMAP_PAI(pm, ti);
684                     kcpuset_remove(pm_active, ti->ti_kcpuset);
685                     TLBINFO_LOCK(ti);
686                     cpuid_t j = kcpuset_ffs_intersecting(pm->pm_onproc,
687                         ti->ti_kcpuset);
688                     // post decrement since ffs returns bit + 1 or 0 if no bit
689                     if (j-- > 0) {
690                               if (kernel_p) {
691                                         ti->ti_tlbinvop =
692                                             TLBINV_KERNEL_MAP(ti->ti_tlbinvop);
693                                         ti->ti_victim = NULL;
694                               } else {
695                                         KASSERT(pai->pai_asid);
696                                         if (__predict_false(ti->ti_victim == pm)) {
697                                                   KASSERT(ti->ti_tlbinvop == TLBINV_ONE);
698                                                   /*
699                                                    * We still need to invalidate this one
700                                                    * ASID so there's nothing to change.
701                                                    */
702                                         } else {
703                                                   ti->ti_tlbinvop =
704                                                       TLBINV_USER_MAP(ti->ti_tlbinvop);
705                                                   if (ti->ti_tlbinvop == TLBINV_ONE)
706                                                             ti->ti_victim = pm;
707                                                   else
708                                                             ti->ti_victim = NULL;
709                                         }
710                               }
711                               UVMHIST_LOG(maphist, "tlbinvop %jx victim %#jx", ti->ti_tlbinvop,
712                                   (uintptr_t)ti->ti_victim, 0, 0);
713                               TLBINFO_UNLOCK(ti);
714                               /*
715                                * Now we can send out the shootdown IPIs to a CPU
716                                * that shares this TLB and is currently using this
717                                * pmap.  That CPU will process the IPI and do the
718                                * all the work.  Any other CPUs sharing that TLB
719                                * will take advantage of that work.  pm_onproc might
720                                * change now that we have released the lock but we
721                                * can tolerate spurious shootdowns.
722                                */
723                               cpu_send_ipi(cpu_lookup(j), IPI_SHOOTDOWN);
724                               ipi_sent = true;
725                               continue;
726                     }
727                     if (!pmap_tlb_intersecting_active_p(pm, ti)) {
728                               UVMHIST_LOG(maphist, "pm %#jx not active", (uintptr_t)pm, 0, 0, 0);
729                               /*
730                                * If this pmap has an ASID assigned but it's not
731                                * currently running, nuke its ASID.  Next time the
732                                * pmap is activated, it will allocate a new ASID.
733                                * And best of all, we avoid an IPI.
734                                */
735                               KASSERT(!kernel_p);
736                               pmap_tlb_pai_reset(ti, pai, pm);
737                               //ti->ti_evcnt_lazy_shots.ev_count++;
738                     }
739                     TLBINFO_UNLOCK(ti);
740           }
741 
742           UVMHIST_LOG(maphist, " <-- done (ipi_sent=%jd)", ipi_sent, 0, 0, 0);
743 
744           return ipi_sent;
745 }
746 #endif /* MULTIPROCESSOR && PMAP_TLB_NEED_SHOOTDOWN */
747 
748 int
pmap_tlb_update_addr(pmap_t pm,vaddr_t va,pt_entry_t pte,u_int flags)749 pmap_tlb_update_addr(pmap_t pm, vaddr_t va, pt_entry_t pte, u_int flags)
750 {
751           KASSERT(kpreempt_disabled());
752 
753           struct pmap_tlb_info * const ti = cpu_tlb_info(curcpu());
754           struct pmap_asid_info * const pai = PMAP_PAI(pm, ti);
755           int rv = -1;
756 
757           UVMHIST_FUNC(__func__);
758           UVMHIST_CALLARGS(maphist, " (pm=%#jx va=%#jx, pte=%#jx flags=%#jx)",
759               (uintptr_t)pm, va, pte_value(pte), flags);
760 
761           KASSERTMSG(pte_valid_p(pte), "va %#"PRIxVADDR" %#"PRIxPTE,
762               va, pte_value(pte));
763 
764           TLBINFO_LOCK(ti);
765           if (pm == pmap_kernel() || PMAP_PAI_ASIDVALID_P(pai, ti)) {
766                     pmap_tlb_asid_check();
767                     rv = tlb_update_addr(va, pai->pai_asid, pte,
768                         (flags & PMAP_TLB_INSERT) != 0);
769                     pmap_tlb_asid_check();
770                     UVMHIST_LOG(maphist,
771                         "   %jd <-- tlb_update_addr(%#jx, %#jx, %#jx, ...)",
772                         rv, va, pai->pai_asid, pte_value(pte));
773                     KASSERTMSG((flags & PMAP_TLB_INSERT) == 0 || rv == 1,
774                         "pmap %p (asid %u) va %#"PRIxVADDR" pte %#"PRIxPTE" rv %d",
775                         pm, pai->pai_asid, va, pte_value(pte), rv);
776           }
777 #if defined(MULTIPROCESSOR) && defined(PMAP_TLB_NEED_SHOOTDOWN)
778           if (flags & PMAP_TLB_NEED_IPI)
779                     pm->pm_shootdown_pending = 1;
780 #endif
781           TLBINFO_UNLOCK(ti);
782 
783           UVMHIST_LOG(maphist, "   <-- done (rv=%jd)", rv, 0, 0, 0);
784 
785           return rv;
786 }
787 
788 void
pmap_tlb_invalidate_addr(pmap_t pm,vaddr_t va)789 pmap_tlb_invalidate_addr(pmap_t pm, vaddr_t va)
790 {
791           KASSERT(kpreempt_disabled());
792 
793           struct pmap_tlb_info * const ti = cpu_tlb_info(curcpu());
794           struct pmap_asid_info * const pai = PMAP_PAI(pm, ti);
795 
796           UVMHIST_FUNC(__func__);
797           UVMHIST_CALLARGS(maphist, " (pm=%#jx va=%#jx) ti=%#jx asid=%#jx",
798               (uintptr_t)pm, va, (uintptr_t)ti, pai->pai_asid);
799 
800           TLBINFO_LOCK(ti);
801           if (pm == pmap_kernel() || PMAP_PAI_ASIDVALID_P(pai, ti)) {
802                     pmap_tlb_asid_check();
803                     UVMHIST_LOG(maphist, " invalidating %#jx asid %#jx",
804                         va, pai->pai_asid, 0, 0);
805                     tlb_invalidate_addr(va, pai->pai_asid);
806                     pmap_tlb_asid_check();
807           }
808 #if defined(MULTIPROCESSOR) && defined(PMAP_TLB_NEED_SHOOTDOWN)
809           pm->pm_shootdown_pending = 1;
810 #endif
811           TLBINFO_UNLOCK(ti);
812           UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
813 }
814 
815 static inline void
pmap_tlb_asid_alloc(struct pmap_tlb_info * ti,pmap_t pm,struct pmap_asid_info * pai)816 pmap_tlb_asid_alloc(struct pmap_tlb_info *ti, pmap_t pm,
817           struct pmap_asid_info *pai)
818 {
819           /*
820            * We shouldn't have an ASID assigned, and thusly must not be onproc
821            * nor active.
822            */
823           KASSERT(pm != pmap_kernel());
824           KASSERT(pai->pai_asid == 0);
825           KASSERT(pai->pai_link.le_prev == NULL);
826 #if defined(MULTIPROCESSOR)
827           KASSERT(!pmap_tlb_intersecting_onproc_p(pm, ti));
828           KASSERT(!pmap_tlb_intersecting_active_p(pm, ti));
829 #endif
830           KASSERT(ti->ti_asids_free > 0);
831           KASSERT(ti->ti_asid_hint > KERNEL_PID);
832 
833           /*
834            * If the last ASID allocated was the maximum ASID, then the
835            * hint will be out of range.  Reset the hint to first
836            * available ASID.
837            */
838           if (PMAP_TLB_FLUSH_ASID_ON_RESET
839               && ti->ti_asid_hint > ti->ti_asid_max) {
840                     ti->ti_asid_hint = KERNEL_PID + 1;
841           }
842           KASSERTMSG(ti->ti_asid_hint <= ti->ti_asid_max, "hint %u",
843               ti->ti_asid_hint);
844 
845           /*
846            * Let's see if the hinted ASID is free.  If not search for
847            * a new one.
848            */
849           if (__predict_true(TLBINFO_ASID_INUSE_P(ti, ti->ti_asid_hint))) {
850                     const size_t nbpw = NBBY * sizeof(ti->ti_asid_bitmap._b[0]);
851                     size_t i;
852                     u_long bits;
853                     for (i = 0; (bits = ~ti->ti_asid_bitmap._b[i]) == 0; i++) {
854                               KASSERT(i < __arraycount(ti->ti_asid_bitmap._b) - 1);
855                     }
856                     /*
857                      * ffs wants to find the first bit set while we want
858                      * to find the first bit cleared.
859                      */
860                     const u_int n = __builtin_ffsl(bits) - 1;
861                     KASSERTMSG((bits << (nbpw - (n+1))) == (1ul << (nbpw-1)),
862                         "n %u bits %#lx", n, bits);
863                     KASSERT(n < nbpw);
864                     ti->ti_asid_hint = n + i * nbpw;
865           }
866 
867           KASSERT(ti->ti_asid_hint > KERNEL_PID);
868           KASSERT(ti->ti_asid_hint <= ti->ti_asid_max);
869           KASSERTMSG(PMAP_TLB_FLUSH_ASID_ON_RESET
870               || TLBINFO_ASID_INUSE_P(ti, ti->ti_asid_hint - 1),
871               "hint %u bitmap %p", ti->ti_asid_hint, &ti->ti_asid_bitmap);
872           KASSERTMSG(!TLBINFO_ASID_INUSE_P(ti, ti->ti_asid_hint),
873               "hint %u bitmap %p", ti->ti_asid_hint, &ti->ti_asid_bitmap);
874 
875           /*
876            * The hint contains our next ASID so take it and advance the hint.
877            * Mark it as used and insert the pai into the list of active asids.
878            * There is also one less asid free in this TLB.
879            */
880           pai->pai_asid = ti->ti_asid_hint++;
881 #ifdef MULTIPROCESSOR
882           if (PMAP_TLB_FLUSH_ASID_ON_RESET) {
883                     /*
884                      * Clean the new ASID from the TLB.
885                      */
886                     tlb_invalidate_asids(pai->pai_asid, pai->pai_asid);
887           }
888 #endif
889           TLBINFO_ASID_MARK_USED(ti, pai->pai_asid);
890           LIST_INSERT_HEAD(&ti->ti_pais, pai, pai_link);
891           ti->ti_asids_free--;
892 
893 #if defined(MULTIPROCESSOR)
894           /*
895            * Mark that we now have an active ASID for all CPUs sharing this TLB.
896            * The bits in pm_active belonging to this TLB can only be changed
897            * while this TLBs lock is held.
898            */
899 #if PMAP_TLB_MAX == 1
900           kcpuset_copy(pm->pm_active, kcpuset_running);
901 #else
902           kcpuset_merge(pm->pm_active, ti->ti_kcpuset);
903 #endif
904 #endif
905 }
906 
907 /*
908  * Acquire a TLB address space tag (called ASID or TLBPID) and return it.
909  * ASID might have already been previously acquired.
910  */
911 void
pmap_tlb_asid_acquire(pmap_t pm,struct lwp * l)912 pmap_tlb_asid_acquire(pmap_t pm, struct lwp *l)
913 {
914           KASSERT(kpreempt_disabled());
915 
916           struct cpu_info * const ci = l->l_cpu;
917           struct pmap_tlb_info * const ti = cpu_tlb_info(ci);
918           struct pmap_asid_info * const pai = PMAP_PAI(pm, ti);
919 
920           UVMHIST_FUNC(__func__);
921           UVMHIST_CALLARGS(maphist, "(pm=%#jx, l=%#jx, ti=%#jx)", (uintptr_t)pm,
922               (uintptr_t)l, (uintptr_t)ti, 0);
923 
924           /*
925            * Kernels use a fixed ASID and thus doesn't need to acquire one.
926            */
927           if (pm == pmap_kernel()) {
928                     UVMHIST_LOG(maphist, " <-- done (kernel)", 0, 0, 0, 0);
929                     return;
930           }
931 
932           TLBINFO_LOCK(ti);
933           KASSERT(pai->pai_asid <= KERNEL_PID || pai->pai_link.le_prev != NULL);
934           KASSERT(pai->pai_asid > KERNEL_PID || pai->pai_link.le_prev == NULL);
935           pmap_tlb_pai_check(ti, true);
936 
937           if (__predict_false(!tlbinfo_asids_p(ti))) {
938 #if defined(MULTIPROCESSOR)
939                     /*
940                      * Mark that we are active for all CPUs sharing this TLB.
941                      * The bits in pm_active belonging to this TLB can only
942                      * be changed  while this TLBs lock is held.
943                      */
944 #if PMAP_TLB_MAX == 1
945                     kcpuset_copy(pm->pm_active, kcpuset_running);
946 #else
947                     kcpuset_merge(pm->pm_active, ti->ti_kcpuset);
948 #endif
949 #endif
950           } else if (__predict_false(!PMAP_PAI_ASIDVALID_P(pai, ti))) {
951                     /*
952                      * If we've run out ASIDs, reinitialize the ASID space.
953                      */
954                     if (__predict_false(tlbinfo_noasids_p(ti))) {
955                               KASSERT(l == curlwp);
956                               UVMHIST_LOG(maphist, " asid reinit", 0, 0, 0, 0);
957                               pmap_tlb_asid_reinitialize(ti, TLBINV_NOBODY);
958                               KASSERT(!tlbinfo_noasids_p(ti));
959                     }
960 
961                     /*
962                      * Get an ASID.
963                      */
964                     pmap_tlb_asid_alloc(ti, pm, pai);
965                     UVMHIST_LOG(maphist, "allocated asid %#jx", pai->pai_asid,
966                         0, 0, 0);
967           }
968           pmap_tlb_pai_check(ti, true);
969 #if defined(MULTIPROCESSOR)
970           KASSERT(kcpuset_isset(pm->pm_active, cpu_index(ci)));
971 #endif
972 
973           if (l == curlwp) {
974 #if defined(MULTIPROCESSOR)
975                     /*
976                      * The bits in pm_onproc belonging to this TLB can only
977                      * be changed while this TLBs lock is held unless atomic
978                      * operations are used.
979                      */
980                     KASSERT(pm != pmap_kernel());
981                     kcpuset_atomic_set(pm->pm_onproc, cpu_index(ci));
982 #endif
983                     ci->ci_pmap_asid_cur = pai->pai_asid;
984                     UVMHIST_LOG(maphist, "setting asid to %#jx", pai->pai_asid,
985                         0, 0, 0);
986                     tlb_set_asid(pai->pai_asid, pm);
987                     pmap_tlb_asid_check();
988           } else {
989                     printf("%s: l (%p) != curlwp %p\n", __func__, l, curlwp);
990           }
991           TLBINFO_UNLOCK(ti);
992           UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
993 }
994 
995 void
pmap_tlb_asid_deactivate(pmap_t pm)996 pmap_tlb_asid_deactivate(pmap_t pm)
997 {
998           UVMHIST_FUNC(__func__);
999           UVMHIST_CALLARGS(maphist, "pm %#jx", (uintptr_t)pm, 0, 0, 0);
1000 
1001           KASSERT(kpreempt_disabled());
1002 #if defined(MULTIPROCESSOR)
1003           /*
1004            * The kernel pmap is aways onproc and active and must never have
1005            * those bits cleared.  If pmap_remove_all was called, it has already
1006            * deactivated the pmap and thusly onproc will be 0 so there's nothing
1007            * to do.
1008            */
1009           if (pm != pmap_kernel() && !kcpuset_iszero(pm->pm_onproc)) {
1010                     struct cpu_info * const ci = curcpu();
1011                     KASSERT(!cpu_intr_p());
1012                     KASSERTMSG(kcpuset_isset(pm->pm_onproc, cpu_index(ci)),
1013                         "%s: pmap %p onproc %p doesn't include cpu %d (%p)",
1014                         __func__, pm, pm->pm_onproc, cpu_index(ci), ci);
1015                     /*
1016                      * The bits in pm_onproc that belong to this TLB can
1017                      * be changed while this TLBs lock is not held as long
1018                      * as we use atomic ops.
1019                      */
1020                     kcpuset_atomic_clear(pm->pm_onproc, cpu_index(ci));
1021           }
1022 #endif
1023           curcpu()->ci_pmap_asid_cur = KERNEL_PID;
1024           tlb_set_asid(KERNEL_PID, pmap_kernel());
1025 
1026           pmap_tlb_pai_check(cpu_tlb_info(curcpu()), false);
1027 #if defined(DEBUG)
1028           pmap_tlb_asid_check();
1029 #endif
1030           UVMHIST_LOG(maphist, " <-- done (pm=%#jx)", (uintptr_t)pm, 0, 0, 0);
1031 }
1032 
1033 void
pmap_tlb_asid_release_all(struct pmap * pm)1034 pmap_tlb_asid_release_all(struct pmap *pm)
1035 {
1036           UVMHIST_FUNC(__func__);
1037           UVMHIST_CALLARGS(maphist, "(pm=%#jx)", (uintptr_t)pm, 0, 0, 0);
1038 
1039           KASSERT(pm != pmap_kernel());
1040 #if defined(MULTIPROCESSOR)
1041           //KASSERT(!kcpuset_iszero(pm->pm_onproc)); // XXX
1042           struct cpu_info * const ci __diagused = curcpu();
1043           KASSERT(!kcpuset_isotherset(pm->pm_onproc, cpu_index(ci)));
1044 #if PMAP_TLB_MAX > 1
1045           for (u_int i = 0; !kcpuset_iszero(pm->pm_active); i++) {
1046                     KASSERT(i < pmap_ntlbs);
1047                     struct pmap_tlb_info * const ti = pmap_tlbs[i];
1048 #else
1049                     struct pmap_tlb_info * const ti = &pmap_tlb0_info;
1050 #endif
1051                     struct pmap_asid_info * const pai = PMAP_PAI(pm, ti);
1052                     TLBINFO_LOCK(ti);
1053                     if (PMAP_PAI_ASIDVALID_P(pai, ti)) {
1054                               /*
1055                                * This pmap should not be in use by any other cpu so
1056                                * we can just reset and be happy.
1057                                */
1058                               if (ti->ti_victim == pm)
1059                                         ti->ti_victim = NULL;
1060                               if (__predict_true(tlbinfo_asids_p(ti)))
1061                                         pmap_tlb_pai_reset(ti, pai, pm);
1062                     }
1063                     KASSERT(pai->pai_link.le_prev == NULL);
1064                     TLBINFO_UNLOCK(ti);
1065 #if PMAP_TLB_MAX > 1
1066           }
1067 #endif
1068 #ifdef DIAGNOSTIC
1069           for (size_t i = 0; i < (PMAP_TLB_MAX > 1 ? pmap_ntlbs : 1); i++) {
1070                     KASSERTMSG(pm->pm_pai[i].pai_asid == 0,
1071                         "pm %p i %zu asid %u",
1072                         pm, i, pm->pm_pai[i].pai_asid);
1073           }
1074 #endif
1075 #else
1076           /*
1077            * Handle the case of an UP kernel which only has, at most, one TLB.
1078            * If the pmap has an ASID allocated, free it.
1079            */
1080           struct pmap_tlb_info * const ti = &pmap_tlb0_info;
1081           struct pmap_asid_info * const pai = PMAP_PAI(pm, ti);
1082           TLBINFO_LOCK(ti);
1083           if (pai->pai_asid > KERNEL_PID) {
1084                     if (curcpu()->ci_pmap_asid_cur == pai->pai_asid) {
1085                               tlb_invalidate_asids(pai->pai_asid, pai->pai_asid);
1086                     } else {
1087                               pmap_tlb_pai_reset(ti, pai, pm);
1088                     }
1089           }
1090           TLBINFO_UNLOCK(ti);
1091 #endif /* MULTIPROCESSOR */
1092           UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
1093 }
1094 
1095 void
pmap_tlb_asid_check(void)1096 pmap_tlb_asid_check(void)
1097 {
1098           UVMHIST_FUNC(__func__);
1099           UVMHIST_CALLED(maphist);
1100 
1101 #ifdef DEBUG
1102           kpreempt_disable();
1103           const tlb_asid_t asid __debugused = tlb_get_asid();
1104           UVMHIST_LOG(maphist, " asid %u vs pmap_cur_asid %u", asid,
1105               curcpu()->ci_pmap_asid_cur, 0, 0);
1106           KDASSERTMSG(asid == curcpu()->ci_pmap_asid_cur,
1107              "%s: asid (%#x) != current asid (%#x)",
1108               __func__, asid, curcpu()->ci_pmap_asid_cur);
1109           kpreempt_enable();
1110 #endif
1111           UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
1112 }
1113 
1114 #ifdef DEBUG
1115 void
pmap_tlb_check(pmap_t pm,bool (* func)(void *,vaddr_t,tlb_asid_t,pt_entry_t))1116 pmap_tlb_check(pmap_t pm, bool (*func)(void *, vaddr_t, tlb_asid_t, pt_entry_t))
1117 {
1118           struct pmap_tlb_info * const ti = cpu_tlb_info(curcpu());
1119           struct pmap_asid_info * const pai = PMAP_PAI(pm, ti);
1120           TLBINFO_LOCK(ti);
1121           if (pm == pmap_kernel() || pai->pai_asid > KERNEL_PID)
1122                     tlb_walk(pm, func);
1123           TLBINFO_UNLOCK(ti);
1124 }
1125 #endif /* DEBUG */
1126 
1127 #ifdef DDB
1128 void
1129 pmap_db_tlb_print(struct pmap *pm,
1130     void (*pr)(const char *, ...) __printflike(1, 2))
1131 {
1132 #if !defined(MULTIPROCESSOR) || PMAP_TLB_MAX == 1
1133           pr(" asid %5u\n", pm->pm_pai[0].pai_asid);
1134 #else
1135           for (size_t i = 0; i < (PMAP_TLB_MAX > 1 ? pmap_ntlbs : 1); i++) {
1136                     pr(" tlb %zu  asid %5u\n", i, pm->pm_pai[i].pai_asid);
1137           }
1138 #endif
1139 }
1140 #endif /* DDB */
1141