mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / arch / ia64 / kernel / ivt.S
blob1efcbe5f0c78183f7571a58a5c0fe98767a04d34
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * arch/ia64/kernel/ivt.S
4  *
5  * Copyright (C) 1998-2001, 2003, 2005 Hewlett-Packard Co
6  *      Stephane Eranian <eranian@hpl.hp.com>
7  *      David Mosberger <davidm@hpl.hp.com>
8  * Copyright (C) 2000, 2002-2003 Intel Co
9  *      Asit Mallick <asit.k.mallick@intel.com>
10  *      Suresh Siddha <suresh.b.siddha@intel.com>
11  *      Kenneth Chen <kenneth.w.chen@intel.com>
12  *      Fenghua Yu <fenghua.yu@intel.com>
13  *
14  * 00/08/23 Asit Mallick <asit.k.mallick@intel.com> TLB handling for SMP
15  * 00/12/20 David Mosberger-Tang <davidm@hpl.hp.com> DTLB/ITLB handler now uses virtual PT.
16  *
17  * Copyright (C) 2005 Hewlett-Packard Co
18  *      Dan Magenheimer <dan.magenheimer@hp.com>
19  *      Xen paravirtualization
20  * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
21  *                    VA Linux Systems Japan K.K.
22  *                    pv_ops.
23  *      Yaozu (Eddie) Dong <eddie.dong@intel.com>
24  */
26  * This file defines the interruption vector table used by the CPU.
27  * It does not include one entry per possible cause of interruption.
28  *
29  * The first 20 entries of the table contain 64 bundles each while the
30  * remaining 48 entries contain only 16 bundles each.
31  *
32  * The 64 bundles are used to allow inlining the whole handler for critical
33  * interruptions like TLB misses.
34  *
35  *  For each entry, the comment is as follows:
36  *
37  *              // 0x1c00 Entry 7 (size 64 bundles) Data Key Miss (12,51)
38  *  entry offset ----/     /         /                  /          /
39  *  entry number ---------/         /                  /          /
40  *  size of the entry -------------/                  /          /
41  *  vector name -------------------------------------/          /
42  *  interruptions triggering this vector ----------------------/
43  *
44  * The table is 32KB in size and must be aligned on 32KB boundary.
45  * (The CPU ignores the 15 lower bits of the address)
46  *
47  * Table is based upon EAS2.6 (Oct 1999)
48  */
51 #include <asm/asmmacro.h>
52 #include <asm/break.h>
53 #include <asm/kregs.h>
54 #include <asm/asm-offsets.h>
55 #include <asm/pgtable.h>
56 #include <asm/processor.h>
57 #include <asm/ptrace.h>
58 #include <asm/thread_info.h>
59 #include <asm/unistd.h>
60 #include <asm/errno.h>
61 #include <asm/export.h>
63 #if 0
64 # define PSR_DEFAULT_BITS       psr.ac
65 #else
66 # define PSR_DEFAULT_BITS       0
67 #endif
69 #if 0
70   /*
71    * This lets you track the last eight faults that occurred on the CPU.  Make sure ar.k2 isn't
72    * needed for something else before enabling this...
73    */
74 # define DBG_FAULT(i)   mov r16=ar.k2;; shl r16=r16,8;; add r16=(i),r16;;mov ar.k2=r16
75 #else
76 # define DBG_FAULT(i)
77 #endif
79 #include "minstate.h"
81 #define FAULT(n)                                                                        \
82         mov r31=pr;                                                                     \
83         mov r19=n;;                     /* prepare to save predicates */                \
84         br.sptk.many dispatch_to_fault_handler
86         .section .text..ivt,"ax"
88         .align 32768    // align on 32KB boundary
89         .global ia64_ivt
90         EXPORT_DATA_SYMBOL(ia64_ivt)
91 ia64_ivt:
92 /////////////////////////////////////////////////////////////////////////////////////////
93 // 0x0000 Entry 0 (size 64 bundles) VHPT Translation (8,20,47)
94 ENTRY(vhpt_miss)
95         DBG_FAULT(0)
96         /*
97          * The VHPT vector is invoked when the TLB entry for the virtual page table
98          * is missing.  This happens only as a result of a previous
99          * (the "original") TLB miss, which may either be caused by an instruction
100          * fetch or a data access (or non-access).
101          *
102          * What we do here is normal TLB miss handing for the _original_ miss,
103          * followed by inserting the TLB entry for the virtual page table page
104          * that the VHPT walker was attempting to access.  The latter gets
105          * inserted as long as page table entry above pte level have valid
106          * mappings for the faulting address.  The TLB entry for the original
107          * miss gets inserted only if the pte entry indicates that the page is
108          * present.
109          *
110          * do_page_fault gets invoked in the following cases:
111          *      - the faulting virtual address uses unimplemented address bits
112          *      - the faulting virtual address has no valid page table mapping
113          */
114         MOV_FROM_IFA(r16)                       // get address that caused the TLB miss
115 #ifdef CONFIG_HUGETLB_PAGE
116         movl r18=PAGE_SHIFT
117         MOV_FROM_ITIR(r25)
118 #endif
119         ;;
120         RSM_PSR_DT                              // use physical addressing for data
121         mov r31=pr                              // save the predicate registers
122         mov r19=IA64_KR(PT_BASE)                // get page table base address
123         shl r21=r16,3                           // shift bit 60 into sign bit
124         shr.u r17=r16,61                        // get the region number into r17
125         ;;
126         shr.u r22=r21,3
127 #ifdef CONFIG_HUGETLB_PAGE
128         extr.u r26=r25,2,6
129         ;;
130         cmp.ne p8,p0=r18,r26
131         sub r27=r26,r18
132         ;;
133 (p8)    dep r25=r18,r25,2,6
134 (p8)    shr r22=r22,r27
135 #endif
136         ;;
137         cmp.eq p6,p7=5,r17                      // is IFA pointing into to region 5?
138         shr.u r18=r22,PGDIR_SHIFT               // get bottom portion of pgd index bit
139         ;;
140 (p7)    dep r17=r17,r19,(PAGE_SHIFT-3),3        // put region number bits in place
142         srlz.d
143         LOAD_PHYSICAL(p6, r19, swapper_pg_dir)  // region 5 is rooted at swapper_pg_dir
145         .pred.rel "mutex", p6, p7
146 (p6)    shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT
147 (p7)    shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT-3
148         ;;
149 (p6)    dep r17=r18,r19,3,(PAGE_SHIFT-3)        // r17=pgd_offset for region 5
150 (p7)    dep r17=r18,r17,3,(PAGE_SHIFT-6)        // r17=pgd_offset for region[0-4]
151         cmp.eq p7,p6=0,r21                      // unused address bits all zeroes?
152 #if CONFIG_PGTABLE_LEVELS == 4
153         shr.u r28=r22,PUD_SHIFT                 // shift pud index into position
154 #else
155         shr.u r18=r22,PMD_SHIFT                 // shift pmd index into position
156 #endif
157         ;;
158         ld8 r17=[r17]                           // get *pgd (may be 0)
159         ;;
160 (p7)    cmp.eq p6,p7=r17,r0                     // was pgd_present(*pgd) == NULL?
161 #if CONFIG_PGTABLE_LEVELS == 4
162         dep r28=r28,r17,3,(PAGE_SHIFT-3)        // r28=pud_offset(pgd,addr)
163         ;;
164         shr.u r18=r22,PMD_SHIFT                 // shift pmd index into position
165 (p7)    ld8 r29=[r28]                           // get *pud (may be 0)
166         ;;
167 (p7)    cmp.eq.or.andcm p6,p7=r29,r0            // was pud_present(*pud) == NULL?
168         dep r17=r18,r29,3,(PAGE_SHIFT-3)        // r17=pmd_offset(pud,addr)
169 #else
170         dep r17=r18,r17,3,(PAGE_SHIFT-3)        // r17=pmd_offset(pgd,addr)
171 #endif
172         ;;
173 (p7)    ld8 r20=[r17]                           // get *pmd (may be 0)
174         shr.u r19=r22,PAGE_SHIFT                // shift pte index into position
175         ;;
176 (p7)    cmp.eq.or.andcm p6,p7=r20,r0            // was pmd_present(*pmd) == NULL?
177         dep r21=r19,r20,3,(PAGE_SHIFT-3)        // r21=pte_offset(pmd,addr)
178         ;;
179 (p7)    ld8 r18=[r21]                           // read *pte
180         MOV_FROM_ISR(r19)                       // cr.isr bit 32 tells us if this is an insn miss
181         ;;
182 (p7)    tbit.z p6,p7=r18,_PAGE_P_BIT            // page present bit cleared?
183         MOV_FROM_IHA(r22)                       // get the VHPT address that caused the TLB miss
184         ;;                                      // avoid RAW on p7
185 (p7)    tbit.nz.unc p10,p11=r19,32              // is it an instruction TLB miss?
186         dep r23=0,r20,0,PAGE_SHIFT              // clear low bits to get page address
187         ;;
188         ITC_I_AND_D(p10, p11, r18, r24)         // insert the instruction TLB entry and
189                                                 // insert the data TLB entry
190 (p6)    br.cond.spnt.many page_fault            // handle bad address/page not present (page fault)
191         MOV_TO_IFA(r22, r24)
193 #ifdef CONFIG_HUGETLB_PAGE
194         MOV_TO_ITIR(p8, r25, r24)               // change to default page-size for VHPT
195 #endif
197         /*
198          * Now compute and insert the TLB entry for the virtual page table.  We never
199          * execute in a page table page so there is no need to set the exception deferral
200          * bit.
201          */
202         adds r24=__DIRTY_BITS_NO_ED|_PAGE_PL_0|_PAGE_AR_RW,r23
203         ;;
204         ITC_D(p7, r24, r25)
205         ;;
206 #ifdef CONFIG_SMP
207         /*
208          * Tell the assemblers dependency-violation checker that the above "itc" instructions
209          * cannot possibly affect the following loads:
210          */
211         dv_serialize_data
213         /*
214          * Re-check pagetable entry.  If they changed, we may have received a ptc.g
215          * between reading the pagetable and the "itc".  If so, flush the entry we
216          * inserted and retry.  At this point, we have:
217          *
218          * r28 = equivalent of pud_offset(pgd, ifa)
219          * r17 = equivalent of pmd_offset(pud, ifa)
220          * r21 = equivalent of pte_offset(pmd, ifa)
221          *
222          * r29 = *pud
223          * r20 = *pmd
224          * r18 = *pte
225          */
226         ld8 r25=[r21]                           // read *pte again
227         ld8 r26=[r17]                           // read *pmd again
228 #if CONFIG_PGTABLE_LEVELS == 4
229         ld8 r19=[r28]                           // read *pud again
230 #endif
231         cmp.ne p6,p7=r0,r0
232         ;;
233         cmp.ne.or.andcm p6,p7=r26,r20           // did *pmd change
234 #if CONFIG_PGTABLE_LEVELS == 4
235         cmp.ne.or.andcm p6,p7=r19,r29           // did *pud change
236 #endif
237         mov r27=PAGE_SHIFT<<2
238         ;;
239 (p6)    ptc.l r22,r27                           // purge PTE page translation
240 (p7)    cmp.ne.or.andcm p6,p7=r25,r18           // did *pte change
241         ;;
242 (p6)    ptc.l r16,r27                           // purge translation
243 #endif
245         mov pr=r31,-1                           // restore predicate registers
246         RFI
247 END(vhpt_miss)
249         .org ia64_ivt+0x400
250 /////////////////////////////////////////////////////////////////////////////////////////
251 // 0x0400 Entry 1 (size 64 bundles) ITLB (21)
252 ENTRY(itlb_miss)
253         DBG_FAULT(1)
254         /*
255          * The ITLB handler accesses the PTE via the virtually mapped linear
256          * page table.  If a nested TLB miss occurs, we switch into physical
257          * mode, walk the page table, and then re-execute the PTE read and
258          * go on normally after that.
259          */
260         MOV_FROM_IFA(r16)                       // get virtual address
261         mov r29=b0                              // save b0
262         mov r31=pr                              // save predicates
263 .itlb_fault:
264         MOV_FROM_IHA(r17)                       // get virtual address of PTE
265         movl r30=1f                             // load nested fault continuation point
266         ;;
267 1:      ld8 r18=[r17]                           // read *pte
268         ;;
269         mov b0=r29
270         tbit.z p6,p0=r18,_PAGE_P_BIT            // page present bit cleared?
271 (p6)    br.cond.spnt page_fault
272         ;;
273         ITC_I(p0, r18, r19)
274         ;;
275 #ifdef CONFIG_SMP
276         /*
277          * Tell the assemblers dependency-violation checker that the above "itc" instructions
278          * cannot possibly affect the following loads:
279          */
280         dv_serialize_data
282         ld8 r19=[r17]                           // read *pte again and see if same
283         mov r20=PAGE_SHIFT<<2                   // setup page size for purge
284         ;;
285         cmp.ne p7,p0=r18,r19
286         ;;
287 (p7)    ptc.l r16,r20
288 #endif
289         mov pr=r31,-1
290         RFI
291 END(itlb_miss)
293         .org ia64_ivt+0x0800
294 /////////////////////////////////////////////////////////////////////////////////////////
295 // 0x0800 Entry 2 (size 64 bundles) DTLB (9,48)
296 ENTRY(dtlb_miss)
297         DBG_FAULT(2)
298         /*
299          * The DTLB handler accesses the PTE via the virtually mapped linear
300          * page table.  If a nested TLB miss occurs, we switch into physical
301          * mode, walk the page table, and then re-execute the PTE read and
302          * go on normally after that.
303          */
304         MOV_FROM_IFA(r16)                       // get virtual address
305         mov r29=b0                              // save b0
306         mov r31=pr                              // save predicates
307 dtlb_fault:
308         MOV_FROM_IHA(r17)                       // get virtual address of PTE
309         movl r30=1f                             // load nested fault continuation point
310         ;;
311 1:      ld8 r18=[r17]                           // read *pte
312         ;;
313         mov b0=r29
314         tbit.z p6,p0=r18,_PAGE_P_BIT            // page present bit cleared?
315 (p6)    br.cond.spnt page_fault
316         ;;
317         ITC_D(p0, r18, r19)
318         ;;
319 #ifdef CONFIG_SMP
320         /*
321          * Tell the assemblers dependency-violation checker that the above "itc" instructions
322          * cannot possibly affect the following loads:
323          */
324         dv_serialize_data
326         ld8 r19=[r17]                           // read *pte again and see if same
327         mov r20=PAGE_SHIFT<<2                   // setup page size for purge
328         ;;
329         cmp.ne p7,p0=r18,r19
330         ;;
331 (p7)    ptc.l r16,r20
332 #endif
333         mov pr=r31,-1
334         RFI
335 END(dtlb_miss)
337         .org ia64_ivt+0x0c00
338 /////////////////////////////////////////////////////////////////////////////////////////
339 // 0x0c00 Entry 3 (size 64 bundles) Alt ITLB (19)
340 ENTRY(alt_itlb_miss)
341         DBG_FAULT(3)
342         MOV_FROM_IFA(r16)       // get address that caused the TLB miss
343         movl r17=PAGE_KERNEL
344         MOV_FROM_IPSR(p0, r21)
345         movl r19=(((1 << IA64_MAX_PHYS_BITS) - 1) & ~0xfff)
346         mov r31=pr
347         ;;
348 #ifdef CONFIG_DISABLE_VHPT
349         shr.u r22=r16,61                        // get the region number into r21
350         ;;
351         cmp.gt p8,p0=6,r22                      // user mode
352         ;;
353         THASH(p8, r17, r16, r23)
354         ;;
355         MOV_TO_IHA(p8, r17, r23)
356 (p8)    mov r29=b0                              // save b0
357 (p8)    br.cond.dptk .itlb_fault
358 #endif
359         extr.u r23=r21,IA64_PSR_CPL0_BIT,2      // extract psr.cpl
360         and r19=r19,r16         // clear ed, reserved bits, and PTE control bits
361         shr.u r18=r16,57        // move address bit 61 to bit 4
362         ;;
363         andcm r18=0x10,r18      // bit 4=~address-bit(61)
364         cmp.ne p8,p0=r0,r23     // psr.cpl != 0?
365         or r19=r17,r19          // insert PTE control bits into r19
366         ;;
367         or r19=r19,r18          // set bit 4 (uncached) if the access was to region 6
368 (p8)    br.cond.spnt page_fault
369         ;;
370         ITC_I(p0, r19, r18)     // insert the TLB entry
371         mov pr=r31,-1
372         RFI
373 END(alt_itlb_miss)
375         .org ia64_ivt+0x1000
376 /////////////////////////////////////////////////////////////////////////////////////////
377 // 0x1000 Entry 4 (size 64 bundles) Alt DTLB (7,46)
378 ENTRY(alt_dtlb_miss)
379         DBG_FAULT(4)
380         MOV_FROM_IFA(r16)       // get address that caused the TLB miss
381         movl r17=PAGE_KERNEL
382         MOV_FROM_ISR(r20)
383         movl r19=(((1 << IA64_MAX_PHYS_BITS) - 1) & ~0xfff)
384         MOV_FROM_IPSR(p0, r21)
385         mov r31=pr
386         mov r24=PERCPU_ADDR
387         ;;
388 #ifdef CONFIG_DISABLE_VHPT
389         shr.u r22=r16,61                        // get the region number into r21
390         ;;
391         cmp.gt p8,p0=6,r22                      // access to region 0-5
392         ;;
393         THASH(p8, r17, r16, r25)
394         ;;
395         MOV_TO_IHA(p8, r17, r25)
396 (p8)    mov r29=b0                              // save b0
397 (p8)    br.cond.dptk dtlb_fault
398 #endif
399         cmp.ge p10,p11=r16,r24                  // access to per_cpu_data?
400         tbit.z p12,p0=r16,61                    // access to region 6?
401         mov r25=PERCPU_PAGE_SHIFT << 2
402         mov r26=PERCPU_PAGE_SIZE
403         nop.m 0
404         nop.b 0
405         ;;
406 (p10)   mov r19=IA64_KR(PER_CPU_DATA)
407 (p11)   and r19=r19,r16                         // clear non-ppn fields
408         extr.u r23=r21,IA64_PSR_CPL0_BIT,2      // extract psr.cpl
409         and r22=IA64_ISR_CODE_MASK,r20          // get the isr.code field
410         tbit.nz p6,p7=r20,IA64_ISR_SP_BIT       // is speculation bit on?
411         tbit.nz p9,p0=r20,IA64_ISR_NA_BIT       // is non-access bit on?
412         ;;
413 (p10)   sub r19=r19,r26
414         MOV_TO_ITIR(p10, r25, r24)
415         cmp.ne p8,p0=r0,r23
416 (p9)    cmp.eq.or.andcm p6,p7=IA64_ISR_CODE_LFETCH,r22  // check isr.code field
417 (p12)   dep r17=-1,r17,4,1                      // set ma=UC for region 6 addr
418 (p8)    br.cond.spnt page_fault
420         dep r21=-1,r21,IA64_PSR_ED_BIT,1
421         ;;
422         or r19=r19,r17          // insert PTE control bits into r19
423         MOV_TO_IPSR(p6, r21, r24)
424         ;;
425         ITC_D(p7, r19, r18)     // insert the TLB entry
426         mov pr=r31,-1
427         RFI
428 END(alt_dtlb_miss)
430         .org ia64_ivt+0x1400
431 /////////////////////////////////////////////////////////////////////////////////////////
432 // 0x1400 Entry 5 (size 64 bundles) Data nested TLB (6,45)
433 ENTRY(nested_dtlb_miss)
434         /*
435          * In the absence of kernel bugs, we get here when the virtually mapped linear
436          * page table is accessed non-speculatively (e.g., in the Dirty-bit, Instruction
437          * Access-bit, or Data Access-bit faults).  If the DTLB entry for the virtual page
438          * table is missing, a nested TLB miss fault is triggered and control is
439          * transferred to this point.  When this happens, we lookup the pte for the
440          * faulting address by walking the page table in physical mode and return to the
441          * continuation point passed in register r30 (or call page_fault if the address is
442          * not mapped).
443          *
444          * Input:       r16:    faulting address
445          *              r29:    saved b0
446          *              r30:    continuation address
447          *              r31:    saved pr
448          *
449          * Output:      r17:    physical address of PTE of faulting address
450          *              r29:    saved b0
451          *              r30:    continuation address
452          *              r31:    saved pr
453          *
454          * Clobbered:   b0, r18, r19, r21, r22, psr.dt (cleared)
455          */
456         RSM_PSR_DT                              // switch to using physical data addressing
457         mov r19=IA64_KR(PT_BASE)                // get the page table base address
458         shl r21=r16,3                           // shift bit 60 into sign bit
459         MOV_FROM_ITIR(r18)
460         ;;
461         shr.u r17=r16,61                        // get the region number into r17
462         extr.u r18=r18,2,6                      // get the faulting page size
463         ;;
464         cmp.eq p6,p7=5,r17                      // is faulting address in region 5?
465         add r22=-PAGE_SHIFT,r18                 // adjustment for hugetlb address
466         add r18=PGDIR_SHIFT-PAGE_SHIFT,r18
467         ;;
468         shr.u r22=r16,r22
469         shr.u r18=r16,r18
470 (p7)    dep r17=r17,r19,(PAGE_SHIFT-3),3        // put region number bits in place
472         srlz.d
473         LOAD_PHYSICAL(p6, r19, swapper_pg_dir)  // region 5 is rooted at swapper_pg_dir
475         .pred.rel "mutex", p6, p7
476 (p6)    shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT
477 (p7)    shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT-3
478         ;;
479 (p6)    dep r17=r18,r19,3,(PAGE_SHIFT-3)        // r17=pgd_offset for region 5
480 (p7)    dep r17=r18,r17,3,(PAGE_SHIFT-6)        // r17=pgd_offset for region[0-4]
481         cmp.eq p7,p6=0,r21                      // unused address bits all zeroes?
482 #if CONFIG_PGTABLE_LEVELS == 4
483         shr.u r18=r22,PUD_SHIFT                 // shift pud index into position
484 #else
485         shr.u r18=r22,PMD_SHIFT                 // shift pmd index into position
486 #endif
487         ;;
488         ld8 r17=[r17]                           // get *pgd (may be 0)
489         ;;
490 (p7)    cmp.eq p6,p7=r17,r0                     // was pgd_present(*pgd) == NULL?
491         dep r17=r18,r17,3,(PAGE_SHIFT-3)        // r17=p[u|m]d_offset(pgd,addr)
492         ;;
493 #if CONFIG_PGTABLE_LEVELS == 4
494 (p7)    ld8 r17=[r17]                           // get *pud (may be 0)
495         shr.u r18=r22,PMD_SHIFT                 // shift pmd index into position
496         ;;
497 (p7)    cmp.eq.or.andcm p6,p7=r17,r0            // was pud_present(*pud) == NULL?
498         dep r17=r18,r17,3,(PAGE_SHIFT-3)        // r17=pmd_offset(pud,addr)
499         ;;
500 #endif
501 (p7)    ld8 r17=[r17]                           // get *pmd (may be 0)
502         shr.u r19=r22,PAGE_SHIFT                // shift pte index into position
503         ;;
504 (p7)    cmp.eq.or.andcm p6,p7=r17,r0            // was pmd_present(*pmd) == NULL?
505         dep r17=r19,r17,3,(PAGE_SHIFT-3)        // r17=pte_offset(pmd,addr);
506 (p6)    br.cond.spnt page_fault
507         mov b0=r30
508         br.sptk.many b0                         // return to continuation point
509 END(nested_dtlb_miss)
511         .org ia64_ivt+0x1800
512 /////////////////////////////////////////////////////////////////////////////////////////
513 // 0x1800 Entry 6 (size 64 bundles) Instruction Key Miss (24)
514 ENTRY(ikey_miss)
515         DBG_FAULT(6)
516         FAULT(6)
517 END(ikey_miss)
519         .org ia64_ivt+0x1c00
520 /////////////////////////////////////////////////////////////////////////////////////////
521 // 0x1c00 Entry 7 (size 64 bundles) Data Key Miss (12,51)
522 ENTRY(dkey_miss)
523         DBG_FAULT(7)
524         FAULT(7)
525 END(dkey_miss)
527         .org ia64_ivt+0x2000
528 /////////////////////////////////////////////////////////////////////////////////////////
529 // 0x2000 Entry 8 (size 64 bundles) Dirty-bit (54)
530 ENTRY(dirty_bit)
531         DBG_FAULT(8)
532         /*
533          * What we do here is to simply turn on the dirty bit in the PTE.  We need to
534          * update both the page-table and the TLB entry.  To efficiently access the PTE,
535          * we address it through the virtual page table.  Most likely, the TLB entry for
536          * the relevant virtual page table page is still present in the TLB so we can
537          * normally do this without additional TLB misses.  In case the necessary virtual
538          * page table TLB entry isn't present, we take a nested TLB miss hit where we look
539          * up the physical address of the L3 PTE and then continue at label 1 below.
540          */
541         MOV_FROM_IFA(r16)                       // get the address that caused the fault
542         movl r30=1f                             // load continuation point in case of nested fault
543         ;;
544         THASH(p0, r17, r16, r18)                // compute virtual address of L3 PTE
545         mov r29=b0                              // save b0 in case of nested fault
546         mov r31=pr                              // save pr
547 #ifdef CONFIG_SMP
548         mov r28=ar.ccv                          // save ar.ccv
549         ;;
550 1:      ld8 r18=[r17]
551         ;;                                      // avoid RAW on r18
552         mov ar.ccv=r18                          // set compare value for cmpxchg
553         or r25=_PAGE_D|_PAGE_A,r18              // set the dirty and accessed bits
554         tbit.z p7,p6 = r18,_PAGE_P_BIT          // Check present bit
555         ;;
556 (p6)    cmpxchg8.acq r26=[r17],r25,ar.ccv       // Only update if page is present
557         mov r24=PAGE_SHIFT<<2
558         ;;
559 (p6)    cmp.eq p6,p7=r26,r18                    // Only compare if page is present
560         ;;
561         ITC_D(p6, r25, r18)                     // install updated PTE
562         ;;
563         /*
564          * Tell the assemblers dependency-violation checker that the above "itc" instructions
565          * cannot possibly affect the following loads:
566          */
567         dv_serialize_data
569         ld8 r18=[r17]                           // read PTE again
570         ;;
571         cmp.eq p6,p7=r18,r25                    // is it same as the newly installed
572         ;;
573 (p7)    ptc.l r16,r24
574         mov b0=r29                              // restore b0
575         mov ar.ccv=r28
576 #else
577         ;;
578 1:      ld8 r18=[r17]
579         ;;                                      // avoid RAW on r18
580         or r18=_PAGE_D|_PAGE_A,r18              // set the dirty and accessed bits
581         mov b0=r29                              // restore b0
582         ;;
583         st8 [r17]=r18                           // store back updated PTE
584         ITC_D(p0, r18, r16)                     // install updated PTE
585 #endif
586         mov pr=r31,-1                           // restore pr
587         RFI
588 END(dirty_bit)
590         .org ia64_ivt+0x2400
591 /////////////////////////////////////////////////////////////////////////////////////////
592 // 0x2400 Entry 9 (size 64 bundles) Instruction Access-bit (27)
593 ENTRY(iaccess_bit)
594         DBG_FAULT(9)
595         // Like Entry 8, except for instruction access
596         MOV_FROM_IFA(r16)                       // get the address that caused the fault
597         movl r30=1f                             // load continuation point in case of nested fault
598         mov r31=pr                              // save predicates
599 #ifdef CONFIG_ITANIUM
600         /*
601          * Erratum 10 (IFA may contain incorrect address) has "NoFix" status.
602          */
603         MOV_FROM_IPSR(p0, r17)
604         ;;
605         MOV_FROM_IIP(r18)
606         tbit.z p6,p0=r17,IA64_PSR_IS_BIT        // IA64 instruction set?
607         ;;
608 (p6)    mov r16=r18                             // if so, use cr.iip instead of cr.ifa
609 #endif /* CONFIG_ITANIUM */
610         ;;
611         THASH(p0, r17, r16, r18)                // compute virtual address of L3 PTE
612         mov r29=b0                              // save b0 in case of nested fault)
613 #ifdef CONFIG_SMP
614         mov r28=ar.ccv                          // save ar.ccv
615         ;;
616 1:      ld8 r18=[r17]
617         ;;
618         mov ar.ccv=r18                          // set compare value for cmpxchg
619         or r25=_PAGE_A,r18                      // set the accessed bit
620         tbit.z p7,p6 = r18,_PAGE_P_BIT          // Check present bit
621         ;;
622 (p6)    cmpxchg8.acq r26=[r17],r25,ar.ccv       // Only if page present
623         mov r24=PAGE_SHIFT<<2
624         ;;
625 (p6)    cmp.eq p6,p7=r26,r18                    // Only if page present
626         ;;
627         ITC_I(p6, r25, r26)                     // install updated PTE
628         ;;
629         /*
630          * Tell the assemblers dependency-violation checker that the above "itc" instructions
631          * cannot possibly affect the following loads:
632          */
633         dv_serialize_data
635         ld8 r18=[r17]                           // read PTE again
636         ;;
637         cmp.eq p6,p7=r18,r25                    // is it same as the newly installed
638         ;;
639 (p7)    ptc.l r16,r24
640         mov b0=r29                              // restore b0
641         mov ar.ccv=r28
642 #else /* !CONFIG_SMP */
643         ;;
644 1:      ld8 r18=[r17]
645         ;;
646         or r18=_PAGE_A,r18                      // set the accessed bit
647         mov b0=r29                              // restore b0
648         ;;
649         st8 [r17]=r18                           // store back updated PTE
650         ITC_I(p0, r18, r16)                     // install updated PTE
651 #endif /* !CONFIG_SMP */
652         mov pr=r31,-1
653         RFI
654 END(iaccess_bit)
656         .org ia64_ivt+0x2800
657 /////////////////////////////////////////////////////////////////////////////////////////
658 // 0x2800 Entry 10 (size 64 bundles) Data Access-bit (15,55)
659 ENTRY(daccess_bit)
660         DBG_FAULT(10)
661         // Like Entry 8, except for data access
662         MOV_FROM_IFA(r16)                       // get the address that caused the fault
663         movl r30=1f                             // load continuation point in case of nested fault
664         ;;
665         THASH(p0, r17, r16, r18)                // compute virtual address of L3 PTE
666         mov r31=pr
667         mov r29=b0                              // save b0 in case of nested fault)
668 #ifdef CONFIG_SMP
669         mov r28=ar.ccv                          // save ar.ccv
670         ;;
671 1:      ld8 r18=[r17]
672         ;;                                      // avoid RAW on r18
673         mov ar.ccv=r18                          // set compare value for cmpxchg
674         or r25=_PAGE_A,r18                      // set the dirty bit
675         tbit.z p7,p6 = r18,_PAGE_P_BIT          // Check present bit
676         ;;
677 (p6)    cmpxchg8.acq r26=[r17],r25,ar.ccv       // Only if page is present
678         mov r24=PAGE_SHIFT<<2
679         ;;
680 (p6)    cmp.eq p6,p7=r26,r18                    // Only if page is present
681         ;;
682         ITC_D(p6, r25, r26)                     // install updated PTE
683         /*
684          * Tell the assemblers dependency-violation checker that the above "itc" instructions
685          * cannot possibly affect the following loads:
686          */
687         dv_serialize_data
688         ;;
689         ld8 r18=[r17]                           // read PTE again
690         ;;
691         cmp.eq p6,p7=r18,r25                    // is it same as the newly installed
692         ;;
693 (p7)    ptc.l r16,r24
694         mov ar.ccv=r28
695 #else
696         ;;
697 1:      ld8 r18=[r17]
698         ;;                                      // avoid RAW on r18
699         or r18=_PAGE_A,r18                      // set the accessed bit
700         ;;
701         st8 [r17]=r18                           // store back updated PTE
702         ITC_D(p0, r18, r16)                     // install updated PTE
703 #endif
704         mov b0=r29                              // restore b0
705         mov pr=r31,-1
706         RFI
707 END(daccess_bit)
709         .org ia64_ivt+0x2c00
710 /////////////////////////////////////////////////////////////////////////////////////////
711 // 0x2c00 Entry 11 (size 64 bundles) Break instruction (33)
712 ENTRY(break_fault)
713         /*
714          * The streamlined system call entry/exit paths only save/restore the initial part
715          * of pt_regs.  This implies that the callers of system-calls must adhere to the
716          * normal procedure calling conventions.
717          *
718          *   Registers to be saved & restored:
719          *      CR registers: cr.ipsr, cr.iip, cr.ifs
720          *      AR registers: ar.unat, ar.pfs, ar.rsc, ar.rnat, ar.bspstore, ar.fpsr
721          *      others: pr, b0, b6, loadrs, r1, r11, r12, r13, r15
722          *   Registers to be restored only:
723          *      r8-r11: output value from the system call.
724          *
725          * During system call exit, scratch registers (including r15) are modified/cleared
726          * to prevent leaking bits from kernel to user level.
727          */
728         DBG_FAULT(11)
729         mov.m r16=IA64_KR(CURRENT)              // M2 r16 <- current task (12 cyc)
730         MOV_FROM_IPSR(p0, r29)                  // M2 (12 cyc)
731         mov r31=pr                              // I0 (2 cyc)
733         MOV_FROM_IIM(r17)                       // M2 (2 cyc)
734         mov.m r27=ar.rsc                        // M2 (12 cyc)
735         mov r18=__IA64_BREAK_SYSCALL            // A
737         mov.m ar.rsc=0                          // M2
738         mov.m r21=ar.fpsr                       // M2 (12 cyc)
739         mov r19=b6                              // I0 (2 cyc)
740         ;;
741         mov.m r23=ar.bspstore                   // M2 (12 cyc)
742         mov.m r24=ar.rnat                       // M2 (5 cyc)
743         mov.i r26=ar.pfs                        // I0 (2 cyc)
745         invala                                  // M0|1
746         nop.m 0                                 // M
747         mov r20=r1                              // A                    save r1
749         nop.m 0
750         movl r30=sys_call_table                 // X
752         MOV_FROM_IIP(r28)                       // M2 (2 cyc)
753         cmp.eq p0,p7=r18,r17                    // I0 is this a system call?
754 (p7)    br.cond.spnt non_syscall                // B  no ->
755         //
756         // From this point on, we are definitely on the syscall-path
757         // and we can use (non-banked) scratch registers.
758         //
759 ///////////////////////////////////////////////////////////////////////
760         mov r1=r16                              // A    move task-pointer to "addl"-addressable reg
761         mov r2=r16                              // A    setup r2 for ia64_syscall_setup
762         add r9=TI_FLAGS+IA64_TASK_SIZE,r16      // A    r9 = &current_thread_info()->flags
764         adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16
765         adds r15=-1024,r15                      // A    subtract 1024 from syscall number
766         mov r3=NR_syscalls - 1
767         ;;
768         ld1.bias r17=[r16]                      // M0|1 r17 = current->thread.on_ustack flag
769         ld4 r9=[r9]                             // M0|1 r9 = current_thread_info()->flags
770         extr.u r8=r29,41,2                      // I0   extract ei field from cr.ipsr
772         shladd r30=r15,3,r30                    // A    r30 = sys_call_table + 8*(syscall-1024)
773         addl r22=IA64_RBS_OFFSET,r1             // A    compute base of RBS
774         cmp.leu p6,p7=r15,r3                    // A    syscall number in range?
775         ;;
777         lfetch.fault.excl.nt1 [r22]             // M0|1 prefetch RBS
778 (p6)    ld8 r30=[r30]                           // M0|1 load address of syscall entry point
779         tnat.nz.or p7,p0=r15                    // I0   is syscall nr a NaT?
781         mov.m ar.bspstore=r22                   // M2   switch to kernel RBS
782         cmp.eq p8,p9=2,r8                       // A    isr.ei==2?
783         ;;
785 (p8)    mov r8=0                                // A    clear ei to 0
786 (p7)    movl r30=sys_ni_syscall                 // X
788 (p8)    adds r28=16,r28                         // A    switch cr.iip to next bundle
789 (p9)    adds r8=1,r8                            // A    increment ei to next slot
790 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
791         ;;
792         mov b6=r30                              // I0   setup syscall handler branch reg early
793 #else
794         nop.i 0
795         ;;
796 #endif
798         mov.m r25=ar.unat                       // M2 (5 cyc)
799         dep r29=r8,r29,41,2                     // I0   insert new ei into cr.ipsr
800         adds r15=1024,r15                       // A    restore original syscall number
801         //
802         // If any of the above loads miss in L1D, we'll stall here until
803         // the data arrives.
804         //
805 ///////////////////////////////////////////////////////////////////////
806         st1 [r16]=r0                            // M2|3 clear current->thread.on_ustack flag
807 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
808         MOV_FROM_ITC(p0, p14, r30, r18)         // M    get cycle for accounting
809 #else
810         mov b6=r30                              // I0   setup syscall handler branch reg early
811 #endif
812         cmp.eq pKStk,pUStk=r0,r17               // A    were we on kernel stacks already?
814         and r9=_TIF_SYSCALL_TRACEAUDIT,r9       // A    mask trace or audit
815         mov r18=ar.bsp                          // M2 (12 cyc)
816 (pKStk) br.cond.spnt .break_fixup               // B    we're already in kernel-mode -- fix up RBS
817         ;;
818 .back_from_break_fixup:
819 (pUStk) addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r1 // A    compute base of memory stack
820         cmp.eq p14,p0=r9,r0                     // A    are syscalls being traced/audited?
821         br.call.sptk.many b7=ia64_syscall_setup // B
823 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
824         // mov.m r30=ar.itc is called in advance, and r13 is current
825         add r16=TI_AC_STAMP+IA64_TASK_SIZE,r13  // A
826         add r17=TI_AC_LEAVE+IA64_TASK_SIZE,r13  // A
827 (pKStk) br.cond.spnt .skip_accounting           // B    unlikely skip
828         ;;
829         ld8 r18=[r16],TI_AC_STIME-TI_AC_STAMP   // M  get last stamp
830         ld8 r19=[r17],TI_AC_UTIME-TI_AC_LEAVE   // M  time at leave
831         ;;
832         ld8 r20=[r16],TI_AC_STAMP-TI_AC_STIME   // M  cumulated stime
833         ld8 r21=[r17]                           // M  cumulated utime
834         sub r22=r19,r18                         // A  stime before leave
835         ;;
836         st8 [r16]=r30,TI_AC_STIME-TI_AC_STAMP   // M  update stamp
837         sub r18=r30,r19                         // A  elapsed time in user
838         ;;
839         add r20=r20,r22                         // A  sum stime
840         add r21=r21,r18                         // A  sum utime
841         ;;
842         st8 [r16]=r20                           // M  update stime
843         st8 [r17]=r21                           // M  update utime
844         ;;
845 .skip_accounting:
846 #endif
847         mov ar.rsc=0x3                          // M2   set eager mode, pl 0, LE, loadrs=0
848         nop 0
849         BSW_1(r2, r14)                          // B (6 cyc) regs are saved, switch to bank 1
850         ;;
852         SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(r3, r16) // M2   now it's safe to re-enable intr.-collection
853                                                 // M0   ensure interruption collection is on
854         movl r3=ia64_ret_from_syscall           // X
855         ;;
856         mov rp=r3                               // I0   set the real return addr
857 (p10)   br.cond.spnt.many ia64_ret_from_syscall // B    return if bad call-frame or r15 is a NaT
859         SSM_PSR_I(p15, p15, r16)                // M2   restore psr.i
860 (p14)   br.call.sptk.many b6=b6                 // B    invoke syscall-handker (ignore return addr)
861         br.cond.spnt.many ia64_trace_syscall    // B    do syscall-tracing thingamagic
862         // NOT REACHED
863 ///////////////////////////////////////////////////////////////////////
864         // On entry, we optimistically assumed that we're coming from user-space.
865         // For the rare cases where a system-call is done from within the kernel,
866         // we fix things up at this point:
867 .break_fixup:
868         add r1=-IA64_PT_REGS_SIZE,sp            // A    allocate space for pt_regs structure
869         mov ar.rnat=r24                         // M2   restore kernel's AR.RNAT
870         ;;
871         mov ar.bspstore=r23                     // M2   restore kernel's AR.BSPSTORE
872         br.cond.sptk .back_from_break_fixup
873 END(break_fault)
875         .org ia64_ivt+0x3000
876 /////////////////////////////////////////////////////////////////////////////////////////
877 // 0x3000 Entry 12 (size 64 bundles) External Interrupt (4)
878 ENTRY(interrupt)
879         /* interrupt handler has become too big to fit this area. */
880         br.sptk.many __interrupt
881 END(interrupt)
883         .org ia64_ivt+0x3400
884 /////////////////////////////////////////////////////////////////////////////////////////
885 // 0x3400 Entry 13 (size 64 bundles) Reserved
886         DBG_FAULT(13)
887         FAULT(13)
889         .org ia64_ivt+0x3800
890 /////////////////////////////////////////////////////////////////////////////////////////
891 // 0x3800 Entry 14 (size 64 bundles) Reserved
892         DBG_FAULT(14)
893         FAULT(14)
895         /*
896          * There is no particular reason for this code to be here, other than that
897          * there happens to be space here that would go unused otherwise.  If this
898          * fault ever gets "unreserved", simply moved the following code to a more
899          * suitable spot...
900          *
901          * ia64_syscall_setup() is a separate subroutine so that it can
902          *      allocate stacked registers so it can safely demine any
903          *      potential NaT values from the input registers.
904          *
905          * On entry:
906          *      - executing on bank 0 or bank 1 register set (doesn't matter)
907          *      -  r1: stack pointer
908          *      -  r2: current task pointer
909          *      -  r3: preserved
910          *      - r11: original contents (saved ar.pfs to be saved)
911          *      - r12: original contents (sp to be saved)
912          *      - r13: original contents (tp to be saved)
913          *      - r15: original contents (syscall # to be saved)
914          *      - r18: saved bsp (after switching to kernel stack)
915          *      - r19: saved b6
916          *      - r20: saved r1 (gp)
917          *      - r21: saved ar.fpsr
918          *      - r22: kernel's register backing store base (krbs_base)
919          *      - r23: saved ar.bspstore
920          *      - r24: saved ar.rnat
921          *      - r25: saved ar.unat
922          *      - r26: saved ar.pfs
923          *      - r27: saved ar.rsc
924          *      - r28: saved cr.iip
925          *      - r29: saved cr.ipsr
926          *      - r30: ar.itc for accounting (don't touch)
927          *      - r31: saved pr
928          *      -  b0: original contents (to be saved)
929          * On exit:
930          *      -  p10: TRUE if syscall is invoked with more than 8 out
931          *              registers or r15's Nat is true
932          *      -  r1: kernel's gp
933          *      -  r3: preserved (same as on entry)
934          *      -  r8: -EINVAL if p10 is true
935          *      - r12: points to kernel stack
936          *      - r13: points to current task
937          *      - r14: preserved (same as on entry)
938          *      - p13: preserved
939          *      - p15: TRUE if interrupts need to be re-enabled
940          *      - ar.fpsr: set to kernel settings
941          *      -  b6: preserved (same as on entry)
942          */
943 GLOBAL_ENTRY(ia64_syscall_setup)
944 #if PT(B6) != 0
945 # error This code assumes that b6 is the first field in pt_regs.
946 #endif
947         st8 [r1]=r19                            // save b6
948         add r16=PT(CR_IPSR),r1                  // initialize first base pointer
949         add r17=PT(R11),r1                      // initialize second base pointer
950         ;;
951         alloc r19=ar.pfs,8,0,0,0                // ensure in0-in7 are writable
952         st8 [r16]=r29,PT(AR_PFS)-PT(CR_IPSR)    // save cr.ipsr
953         tnat.nz p8,p0=in0
955         st8.spill [r17]=r11,PT(CR_IIP)-PT(R11)  // save r11
956         tnat.nz p9,p0=in1
957 (pKStk) mov r18=r0                              // make sure r18 isn't NaT
958         ;;
960         st8 [r16]=r26,PT(CR_IFS)-PT(AR_PFS)     // save ar.pfs
961         st8 [r17]=r28,PT(AR_UNAT)-PT(CR_IIP)    // save cr.iip
962         mov r28=b0                              // save b0 (2 cyc)
963         ;;
965         st8 [r17]=r25,PT(AR_RSC)-PT(AR_UNAT)    // save ar.unat
966         dep r19=0,r19,38,26                     // clear all bits but 0..37 [I0]
967 (p8)    mov in0=-1
968         ;;
970         st8 [r16]=r19,PT(AR_RNAT)-PT(CR_IFS)    // store ar.pfs.pfm in cr.ifs
971         extr.u r11=r19,7,7      // I0           // get sol of ar.pfs
972         and r8=0x7f,r19         // A            // get sof of ar.pfs
974         st8 [r17]=r27,PT(AR_BSPSTORE)-PT(AR_RSC)// save ar.rsc
975         tbit.nz p15,p0=r29,IA64_PSR_I_BIT // I0
976 (p9)    mov in1=-1
977         ;;
979 (pUStk) sub r18=r18,r22                         // r18=RSE.ndirty*8
980         tnat.nz p10,p0=in2
981         add r11=8,r11
982         ;;
983 (pKStk) adds r16=PT(PR)-PT(AR_RNAT),r16         // skip over ar_rnat field
984 (pKStk) adds r17=PT(B0)-PT(AR_BSPSTORE),r17     // skip over ar_bspstore field
985         tnat.nz p11,p0=in3
986         ;;
987 (p10)   mov in2=-1
988         tnat.nz p12,p0=in4                              // [I0]
989 (p11)   mov in3=-1
990         ;;
991 (pUStk) st8 [r16]=r24,PT(PR)-PT(AR_RNAT)        // save ar.rnat
992 (pUStk) st8 [r17]=r23,PT(B0)-PT(AR_BSPSTORE)    // save ar.bspstore
993         shl r18=r18,16                          // compute ar.rsc to be used for "loadrs"
994         ;;
995         st8 [r16]=r31,PT(LOADRS)-PT(PR)         // save predicates
996         st8 [r17]=r28,PT(R1)-PT(B0)             // save b0
997         tnat.nz p13,p0=in5                              // [I0]
998         ;;
999         st8 [r16]=r18,PT(R12)-PT(LOADRS)        // save ar.rsc value for "loadrs"
1000         st8.spill [r17]=r20,PT(R13)-PT(R1)      // save original r1
1001 (p12)   mov in4=-1
1002         ;;
1004 .mem.offset 0,0; st8.spill [r16]=r12,PT(AR_FPSR)-PT(R12)        // save r12
1005 .mem.offset 8,0; st8.spill [r17]=r13,PT(R15)-PT(R13)            // save r13
1006 (p13)   mov in5=-1
1007         ;;
1008         st8 [r16]=r21,PT(R8)-PT(AR_FPSR)        // save ar.fpsr
1009         tnat.nz p13,p0=in6
1010         cmp.lt p10,p9=r11,r8    // frame size can't be more than local+8
1011         ;;
1012         mov r8=1
1013 (p9)    tnat.nz p10,p0=r15
1014         adds r12=-16,r1         // switch to kernel memory stack (with 16 bytes of scratch)
1016         st8.spill [r17]=r15                     // save r15
1017         tnat.nz p8,p0=in7
1018         nop.i 0
1020         mov r13=r2                              // establish `current'
1021         movl r1=__gp                            // establish kernel global pointer
1022         ;;
1023         st8 [r16]=r8            // ensure pt_regs.r8 != 0 (see handle_syscall_error)
1024 (p13)   mov in6=-1
1025 (p8)    mov in7=-1
1027         cmp.eq pSys,pNonSys=r0,r0               // set pSys=1, pNonSys=0
1028         movl r17=FPSR_DEFAULT
1029         ;;
1030         mov.m ar.fpsr=r17                       // set ar.fpsr to kernel default value
1031 (p10)   mov r8=-EINVAL
1032         br.ret.sptk.many b7
1033 END(ia64_syscall_setup)
1035         .org ia64_ivt+0x3c00
1036 /////////////////////////////////////////////////////////////////////////////////////////
1037 // 0x3c00 Entry 15 (size 64 bundles) Reserved
1038         DBG_FAULT(15)
1039         FAULT(15)
1041         .org ia64_ivt+0x4000
1042 /////////////////////////////////////////////////////////////////////////////////////////
1043 // 0x4000 Entry 16 (size 64 bundles) Reserved
1044         DBG_FAULT(16)
1045         FAULT(16)
1047 #if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE)
1048         /*
1049          * There is no particular reason for this code to be here, other than
1050          * that there happens to be space here that would go unused otherwise.
1051          * If this fault ever gets "unreserved", simply moved the following
1052          * code to a more suitable spot...
1053          *
1054          * account_sys_enter is called from SAVE_MIN* macros if accounting is
1055          * enabled and if the macro is entered from user mode.
1056          */
1057 GLOBAL_ENTRY(account_sys_enter)
1058         // mov.m r20=ar.itc is called in advance, and r13 is current
1059         add r16=TI_AC_STAMP+IA64_TASK_SIZE,r13
1060         add r17=TI_AC_LEAVE+IA64_TASK_SIZE,r13
1061         ;;
1062         ld8 r18=[r16],TI_AC_STIME-TI_AC_STAMP   // time at last check in kernel
1063         ld8 r19=[r17],TI_AC_UTIME-TI_AC_LEAVE   // time at left from kernel
1064         ;;
1065         ld8 r23=[r16],TI_AC_STAMP-TI_AC_STIME   // cumulated stime
1066         ld8 r21=[r17]                           // cumulated utime
1067         sub r22=r19,r18                         // stime before leave kernel
1068         ;;
1069         st8 [r16]=r20,TI_AC_STIME-TI_AC_STAMP   // update stamp
1070         sub r18=r20,r19                         // elapsed time in user mode
1071         ;;
1072         add r23=r23,r22                         // sum stime
1073         add r21=r21,r18                         // sum utime
1074         ;;
1075         st8 [r16]=r23                           // update stime
1076         st8 [r17]=r21                           // update utime
1077         ;;
1078         br.ret.sptk.many rp
1079 END(account_sys_enter)
1080 #endif
1082         .org ia64_ivt+0x4400
1083 /////////////////////////////////////////////////////////////////////////////////////////
1084 // 0x4400 Entry 17 (size 64 bundles) Reserved
1085         DBG_FAULT(17)
1086         FAULT(17)
1088         .org ia64_ivt+0x4800
1089 /////////////////////////////////////////////////////////////////////////////////////////
1090 // 0x4800 Entry 18 (size 64 bundles) Reserved
1091         DBG_FAULT(18)
1092         FAULT(18)
1094         .org ia64_ivt+0x4c00
1095 /////////////////////////////////////////////////////////////////////////////////////////
1096 // 0x4c00 Entry 19 (size 64 bundles) Reserved
1097         DBG_FAULT(19)
1098         FAULT(19)
1101 // --- End of long entries, Beginning of short entries
1104         .org ia64_ivt+0x5000
1105 /////////////////////////////////////////////////////////////////////////////////////////
1106 // 0x5000 Entry 20 (size 16 bundles) Page Not Present (10,22,49)
1107 ENTRY(page_not_present)
1108         DBG_FAULT(20)
1109         MOV_FROM_IFA(r16)
1110         RSM_PSR_DT
1111         /*
1112          * The Linux page fault handler doesn't expect non-present pages to be in
1113          * the TLB.  Flush the existing entry now, so we meet that expectation.
1114          */
1115         mov r17=PAGE_SHIFT<<2
1116         ;;
1117         ptc.l r16,r17
1118         ;;
1119         mov r31=pr
1120         srlz.d
1121         br.sptk.many page_fault
1122 END(page_not_present)
1124         .org ia64_ivt+0x5100
1125 /////////////////////////////////////////////////////////////////////////////////////////
1126 // 0x5100 Entry 21 (size 16 bundles) Key Permission (13,25,52)
1127 ENTRY(key_permission)
1128         DBG_FAULT(21)
1129         MOV_FROM_IFA(r16)
1130         RSM_PSR_DT
1131         mov r31=pr
1132         ;;
1133         srlz.d
1134         br.sptk.many page_fault
1135 END(key_permission)
1137         .org ia64_ivt+0x5200
1138 /////////////////////////////////////////////////////////////////////////////////////////
1139 // 0x5200 Entry 22 (size 16 bundles) Instruction Access Rights (26)
1140 ENTRY(iaccess_rights)
1141         DBG_FAULT(22)
1142         MOV_FROM_IFA(r16)
1143         RSM_PSR_DT
1144         mov r31=pr
1145         ;;
1146         srlz.d
1147         br.sptk.many page_fault
1148 END(iaccess_rights)
1150         .org ia64_ivt+0x5300
1151 /////////////////////////////////////////////////////////////////////////////////////////
1152 // 0x5300 Entry 23 (size 16 bundles) Data Access Rights (14,53)
1153 ENTRY(daccess_rights)
1154         DBG_FAULT(23)
1155         MOV_FROM_IFA(r16)
1156         RSM_PSR_DT
1157         mov r31=pr
1158         ;;
1159         srlz.d
1160         br.sptk.many page_fault
1161 END(daccess_rights)
1163         .org ia64_ivt+0x5400
1164 /////////////////////////////////////////////////////////////////////////////////////////
1165 // 0x5400 Entry 24 (size 16 bundles) General Exception (5,32,34,36,38,39)
1166 ENTRY(general_exception)
1167         DBG_FAULT(24)
1168         MOV_FROM_ISR(r16)
1169         mov r31=pr
1170         ;;
1171         cmp4.eq p6,p0=0,r16
1172 (p6)    br.sptk.many dispatch_illegal_op_fault
1173         ;;
1174         mov r19=24              // fault number
1175         br.sptk.many dispatch_to_fault_handler
1176 END(general_exception)
1178         .org ia64_ivt+0x5500
1179 /////////////////////////////////////////////////////////////////////////////////////////
1180 // 0x5500 Entry 25 (size 16 bundles) Disabled FP-Register (35)
1181 ENTRY(disabled_fp_reg)
1182         DBG_FAULT(25)
1183         rsm psr.dfh             // ensure we can access fph
1184         ;;
1185         srlz.d
1186         mov r31=pr
1187         mov r19=25
1188         br.sptk.many dispatch_to_fault_handler
1189 END(disabled_fp_reg)
1191         .org ia64_ivt+0x5600
1192 /////////////////////////////////////////////////////////////////////////////////////////
1193 // 0x5600 Entry 26 (size 16 bundles) Nat Consumption (11,23,37,50)
1194 ENTRY(nat_consumption)
1195         DBG_FAULT(26)
1197         MOV_FROM_IPSR(p0, r16)
1198         MOV_FROM_ISR(r17)
1199         mov r31=pr                              // save PR
1200         ;;
1201         and r18=0xf,r17                         // r18 = cr.ipsr.code{3:0}
1202         tbit.z p6,p0=r17,IA64_ISR_NA_BIT
1203         ;;
1204         cmp.ne.or p6,p0=IA64_ISR_CODE_LFETCH,r18
1205         dep r16=-1,r16,IA64_PSR_ED_BIT,1
1206 (p6)    br.cond.spnt 1f         // branch if (cr.ispr.na == 0 || cr.ipsr.code{3:0} != LFETCH)
1207         ;;
1208         MOV_TO_IPSR(p0, r16, r18)
1209         mov pr=r31,-1
1210         ;;
1211         RFI
1213 1:      mov pr=r31,-1
1214         ;;
1215         FAULT(26)
1216 END(nat_consumption)
1218         .org ia64_ivt+0x5700
1219 /////////////////////////////////////////////////////////////////////////////////////////
1220 // 0x5700 Entry 27 (size 16 bundles) Speculation (40)
1221 ENTRY(speculation_vector)
1222         DBG_FAULT(27)
1223         /*
1224          * A [f]chk.[as] instruction needs to take the branch to the recovery code but
1225          * this part of the architecture is not implemented in hardware on some CPUs, such
1226          * as Itanium.  Thus, in general we need to emulate the behavior.  IIM contains
1227          * the relative target (not yet sign extended).  So after sign extending it we
1228          * simply add it to IIP.  We also need to reset the EI field of the IPSR to zero,
1229          * i.e., the slot to restart into.
1230          *
1231          * cr.imm contains zero_ext(imm21)
1232          */
1233         MOV_FROM_IIM(r18)
1234         ;;
1235         MOV_FROM_IIP(r17)
1236         shl r18=r18,43                  // put sign bit in position (43=64-21)
1237         ;;
1239         MOV_FROM_IPSR(p0, r16)
1240         shr r18=r18,39                  // sign extend (39=43-4)
1241         ;;
1243         add r17=r17,r18                 // now add the offset
1244         ;;
1245         MOV_TO_IIP(r17, r19)
1246         dep r16=0,r16,41,2              // clear EI
1247         ;;
1249         MOV_TO_IPSR(p0, r16, r19)
1250         ;;
1252         RFI
1253 END(speculation_vector)
1255         .org ia64_ivt+0x5800
1256 /////////////////////////////////////////////////////////////////////////////////////////
1257 // 0x5800 Entry 28 (size 16 bundles) Reserved
1258         DBG_FAULT(28)
1259         FAULT(28)
1261         .org ia64_ivt+0x5900
1262 /////////////////////////////////////////////////////////////////////////////////////////
1263 // 0x5900 Entry 29 (size 16 bundles) Debug (16,28,56)
1264 ENTRY(debug_vector)
1265         DBG_FAULT(29)
1266         FAULT(29)
1267 END(debug_vector)
1269         .org ia64_ivt+0x5a00
1270 /////////////////////////////////////////////////////////////////////////////////////////
1271 // 0x5a00 Entry 30 (size 16 bundles) Unaligned Reference (57)
1272 ENTRY(unaligned_access)
1273         DBG_FAULT(30)
1274         mov r31=pr              // prepare to save predicates
1275         ;;
1276         br.sptk.many dispatch_unaligned_handler
1277 END(unaligned_access)
1279         .org ia64_ivt+0x5b00
1280 /////////////////////////////////////////////////////////////////////////////////////////
1281 // 0x5b00 Entry 31 (size 16 bundles) Unsupported Data Reference (57)
1282 ENTRY(unsupported_data_reference)
1283         DBG_FAULT(31)
1284         FAULT(31)
1285 END(unsupported_data_reference)
1287         .org ia64_ivt+0x5c00
1288 /////////////////////////////////////////////////////////////////////////////////////////
1289 // 0x5c00 Entry 32 (size 16 bundles) Floating-Point Fault (64)
1290 ENTRY(floating_point_fault)
1291         DBG_FAULT(32)
1292         FAULT(32)
1293 END(floating_point_fault)
1295         .org ia64_ivt+0x5d00
1296 /////////////////////////////////////////////////////////////////////////////////////////
1297 // 0x5d00 Entry 33 (size 16 bundles) Floating Point Trap (66)
1298 ENTRY(floating_point_trap)
1299         DBG_FAULT(33)
1300         FAULT(33)
1301 END(floating_point_trap)
1303         .org ia64_ivt+0x5e00
1304 /////////////////////////////////////////////////////////////////////////////////////////
1305 // 0x5e00 Entry 34 (size 16 bundles) Lower Privilege Transfer Trap (66)
1306 ENTRY(lower_privilege_trap)
1307         DBG_FAULT(34)
1308         FAULT(34)
1309 END(lower_privilege_trap)
1311         .org ia64_ivt+0x5f00
1312 /////////////////////////////////////////////////////////////////////////////////////////
1313 // 0x5f00 Entry 35 (size 16 bundles) Taken Branch Trap (68)
1314 ENTRY(taken_branch_trap)
1315         DBG_FAULT(35)
1316         FAULT(35)
1317 END(taken_branch_trap)
1319         .org ia64_ivt+0x6000
1320 /////////////////////////////////////////////////////////////////////////////////////////
1321 // 0x6000 Entry 36 (size 16 bundles) Single Step Trap (69)
1322 ENTRY(single_step_trap)
1323         DBG_FAULT(36)
1324         FAULT(36)
1325 END(single_step_trap)
1327         .org ia64_ivt+0x6100
1328 /////////////////////////////////////////////////////////////////////////////////////////
1329 // 0x6100 Entry 37 (size 16 bundles) Reserved
1330         DBG_FAULT(37)
1331         FAULT(37)
1333         .org ia64_ivt+0x6200
1334 /////////////////////////////////////////////////////////////////////////////////////////
1335 // 0x6200 Entry 38 (size 16 bundles) Reserved
1336         DBG_FAULT(38)
1337         FAULT(38)
1339         .org ia64_ivt+0x6300
1340 /////////////////////////////////////////////////////////////////////////////////////////
1341 // 0x6300 Entry 39 (size 16 bundles) Reserved
1342         DBG_FAULT(39)
1343         FAULT(39)
1345         .org ia64_ivt+0x6400
1346 /////////////////////////////////////////////////////////////////////////////////////////
1347 // 0x6400 Entry 40 (size 16 bundles) Reserved
1348         DBG_FAULT(40)
1349         FAULT(40)
1351         .org ia64_ivt+0x6500
1352 /////////////////////////////////////////////////////////////////////////////////////////
1353 // 0x6500 Entry 41 (size 16 bundles) Reserved
1354         DBG_FAULT(41)
1355         FAULT(41)
1357         .org ia64_ivt+0x6600
1358 /////////////////////////////////////////////////////////////////////////////////////////
1359 // 0x6600 Entry 42 (size 16 bundles) Reserved
1360         DBG_FAULT(42)
1361         FAULT(42)
1363         .org ia64_ivt+0x6700
1364 /////////////////////////////////////////////////////////////////////////////////////////
1365 // 0x6700 Entry 43 (size 16 bundles) Reserved
1366         DBG_FAULT(43)
1367         FAULT(43)
1369         .org ia64_ivt+0x6800
1370 /////////////////////////////////////////////////////////////////////////////////////////
1371 // 0x6800 Entry 44 (size 16 bundles) Reserved
1372         DBG_FAULT(44)
1373         FAULT(44)
1375         .org ia64_ivt+0x6900
1376 /////////////////////////////////////////////////////////////////////////////////////////
1377 // 0x6900 Entry 45 (size 16 bundles) IA-32 Exeception (17,18,29,41,42,43,44,58,60,61,62,72,73,75,76,77)
1378 ENTRY(ia32_exception)
1379         DBG_FAULT(45)
1380         FAULT(45)
1381 END(ia32_exception)
1383         .org ia64_ivt+0x6a00
1384 /////////////////////////////////////////////////////////////////////////////////////////
1385 // 0x6a00 Entry 46 (size 16 bundles) IA-32 Intercept  (30,31,59,70,71)
1386 ENTRY(ia32_intercept)
1387         DBG_FAULT(46)
1388         FAULT(46)
1389 END(ia32_intercept)
1391         .org ia64_ivt+0x6b00
1392 /////////////////////////////////////////////////////////////////////////////////////////
1393 // 0x6b00 Entry 47 (size 16 bundles) IA-32 Interrupt  (74)
1394 ENTRY(ia32_interrupt)
1395         DBG_FAULT(47)
1396         FAULT(47)
1397 END(ia32_interrupt)
1399         .org ia64_ivt+0x6c00
1400 /////////////////////////////////////////////////////////////////////////////////////////
1401 // 0x6c00 Entry 48 (size 16 bundles) Reserved
1402         DBG_FAULT(48)
1403         FAULT(48)
1405         .org ia64_ivt+0x6d00
1406 /////////////////////////////////////////////////////////////////////////////////////////
1407 // 0x6d00 Entry 49 (size 16 bundles) Reserved
1408         DBG_FAULT(49)
1409         FAULT(49)
1411         .org ia64_ivt+0x6e00
1412 /////////////////////////////////////////////////////////////////////////////////////////
1413 // 0x6e00 Entry 50 (size 16 bundles) Reserved
1414         DBG_FAULT(50)
1415         FAULT(50)
1417         .org ia64_ivt+0x6f00
1418 /////////////////////////////////////////////////////////////////////////////////////////
1419 // 0x6f00 Entry 51 (size 16 bundles) Reserved
1420         DBG_FAULT(51)
1421         FAULT(51)
1423         .org ia64_ivt+0x7000
1424 /////////////////////////////////////////////////////////////////////////////////////////
1425 // 0x7000 Entry 52 (size 16 bundles) Reserved
1426         DBG_FAULT(52)
1427         FAULT(52)
1429         .org ia64_ivt+0x7100
1430 /////////////////////////////////////////////////////////////////////////////////////////
1431 // 0x7100 Entry 53 (size 16 bundles) Reserved
1432         DBG_FAULT(53)
1433         FAULT(53)
1435         .org ia64_ivt+0x7200
1436 /////////////////////////////////////////////////////////////////////////////////////////
1437 // 0x7200 Entry 54 (size 16 bundles) Reserved
1438         DBG_FAULT(54)
1439         FAULT(54)
1441         .org ia64_ivt+0x7300
1442 /////////////////////////////////////////////////////////////////////////////////////////
1443 // 0x7300 Entry 55 (size 16 bundles) Reserved
1444         DBG_FAULT(55)
1445         FAULT(55)
1447         .org ia64_ivt+0x7400
1448 /////////////////////////////////////////////////////////////////////////////////////////
1449 // 0x7400 Entry 56 (size 16 bundles) Reserved
1450         DBG_FAULT(56)
1451         FAULT(56)
1453         .org ia64_ivt+0x7500
1454 /////////////////////////////////////////////////////////////////////////////////////////
1455 // 0x7500 Entry 57 (size 16 bundles) Reserved
1456         DBG_FAULT(57)
1457         FAULT(57)
1459         .org ia64_ivt+0x7600
1460 /////////////////////////////////////////////////////////////////////////////////////////
1461 // 0x7600 Entry 58 (size 16 bundles) Reserved
1462         DBG_FAULT(58)
1463         FAULT(58)
1465         .org ia64_ivt+0x7700
1466 /////////////////////////////////////////////////////////////////////////////////////////
1467 // 0x7700 Entry 59 (size 16 bundles) Reserved
1468         DBG_FAULT(59)
1469         FAULT(59)
1471         .org ia64_ivt+0x7800
1472 /////////////////////////////////////////////////////////////////////////////////////////
1473 // 0x7800 Entry 60 (size 16 bundles) Reserved
1474         DBG_FAULT(60)
1475         FAULT(60)
1477         .org ia64_ivt+0x7900
1478 /////////////////////////////////////////////////////////////////////////////////////////
1479 // 0x7900 Entry 61 (size 16 bundles) Reserved
1480         DBG_FAULT(61)
1481         FAULT(61)
1483         .org ia64_ivt+0x7a00
1484 /////////////////////////////////////////////////////////////////////////////////////////
1485 // 0x7a00 Entry 62 (size 16 bundles) Reserved
1486         DBG_FAULT(62)
1487         FAULT(62)
1489         .org ia64_ivt+0x7b00
1490 /////////////////////////////////////////////////////////////////////////////////////////
1491 // 0x7b00 Entry 63 (size 16 bundles) Reserved
1492         DBG_FAULT(63)
1493         FAULT(63)
1495         .org ia64_ivt+0x7c00
1496 /////////////////////////////////////////////////////////////////////////////////////////
1497 // 0x7c00 Entry 64 (size 16 bundles) Reserved
1498         DBG_FAULT(64)
1499         FAULT(64)
1501         .org ia64_ivt+0x7d00
1502 /////////////////////////////////////////////////////////////////////////////////////////
1503 // 0x7d00 Entry 65 (size 16 bundles) Reserved
1504         DBG_FAULT(65)
1505         FAULT(65)
1507         .org ia64_ivt+0x7e00
1508 /////////////////////////////////////////////////////////////////////////////////////////
1509 // 0x7e00 Entry 66 (size 16 bundles) Reserved
1510         DBG_FAULT(66)
1511         FAULT(66)
1513         .org ia64_ivt+0x7f00
1514 /////////////////////////////////////////////////////////////////////////////////////////
1515 // 0x7f00 Entry 67 (size 16 bundles) Reserved
1516         DBG_FAULT(67)
1517         FAULT(67)
1519         //-----------------------------------------------------------------------------------
1520         // call do_page_fault (predicates are in r31, psr.dt may be off, r16 is faulting address)
1521 ENTRY(page_fault)
1522         SSM_PSR_DT_AND_SRLZ_I
1523         ;;
1524         SAVE_MIN_WITH_COVER
1525         alloc r15=ar.pfs,0,0,3,0
1526         MOV_FROM_IFA(out0)
1527         MOV_FROM_ISR(out1)
1528         SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(r14, r3)
1529         adds r3=8,r2                            // set up second base pointer
1530         SSM_PSR_I(p15, p15, r14)                // restore psr.i
1531         movl r14=ia64_leave_kernel
1532         ;;
1533         SAVE_REST
1534         mov rp=r14
1535         ;;
1536         adds out2=16,r12                        // out2 = pointer to pt_regs
1537         br.call.sptk.many b6=ia64_do_page_fault // ignore return address
1538 END(page_fault)
1540 ENTRY(non_syscall)
1541         mov ar.rsc=r27                  // restore ar.rsc before SAVE_MIN_WITH_COVER
1542         ;;
1543         SAVE_MIN_WITH_COVER
1545         // There is no particular reason for this code to be here, other than that
1546         // there happens to be space here that would go unused otherwise.  If this
1547         // fault ever gets "unreserved", simply moved the following code to a more
1548         // suitable spot...
1550         alloc r14=ar.pfs,0,0,2,0
1551         MOV_FROM_IIM(out0)
1552         add out1=16,sp
1553         adds r3=8,r2                    // set up second base pointer for SAVE_REST
1555         SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(r15, r24)
1556                                         // guarantee that interruption collection is on
1557         SSM_PSR_I(p15, p15, r15)        // restore psr.i
1558         movl r15=ia64_leave_kernel
1559         ;;
1560         SAVE_REST
1561         mov rp=r15
1562         ;;
1563         br.call.sptk.many b6=ia64_bad_break     // avoid WAW on CFM and ignore return addr
1564 END(non_syscall)
1566 ENTRY(__interrupt)
1567         DBG_FAULT(12)
1568         mov r31=pr              // prepare to save predicates
1569         ;;
1570         SAVE_MIN_WITH_COVER     // uses r31; defines r2 and r3
1571         SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(r3, r14)
1572                                 // ensure everybody knows psr.ic is back on
1573         adds r3=8,r2            // set up second base pointer for SAVE_REST
1574         ;;
1575         SAVE_REST
1576         ;;
1577         MCA_RECOVER_RANGE(interrupt)
1578         alloc r14=ar.pfs,0,0,2,0 // must be first in an insn group
1579         MOV_FROM_IVR(out0, r8)  // pass cr.ivr as first arg
1580         add out1=16,sp          // pass pointer to pt_regs as second arg
1581         ;;
1582         srlz.d                  // make sure we see the effect of cr.ivr
1583         movl r14=ia64_leave_kernel
1584         ;;
1585         mov rp=r14
1586         br.call.sptk.many b6=ia64_handle_irq
1587 END(__interrupt)
1589         /*
1590          * There is no particular reason for this code to be here, other than that
1591          * there happens to be space here that would go unused otherwise.  If this
1592          * fault ever gets "unreserved", simply moved the following code to a more
1593          * suitable spot...
1594          */
1596 ENTRY(dispatch_unaligned_handler)
1597         SAVE_MIN_WITH_COVER
1598         ;;
1599         alloc r14=ar.pfs,0,0,2,0                // now it's safe (must be first in insn group!)
1600         MOV_FROM_IFA(out0)
1601         adds out1=16,sp
1603         SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(r3, r24)
1604                                                 // guarantee that interruption collection is on
1605         SSM_PSR_I(p15, p15, r3)                 // restore psr.i
1606         adds r3=8,r2                            // set up second base pointer
1607         ;;
1608         SAVE_REST
1609         movl r14=ia64_leave_kernel
1610         ;;
1611         mov rp=r14
1612         br.sptk.many ia64_prepare_handle_unaligned
1613 END(dispatch_unaligned_handler)
1615         /*
1616          * There is no particular reason for this code to be here, other than that
1617          * there happens to be space here that would go unused otherwise.  If this
1618          * fault ever gets "unreserved", simply moved the following code to a more
1619          * suitable spot...
1620          */
1622 ENTRY(dispatch_to_fault_handler)
1623         /*
1624          * Input:
1625          *      psr.ic: off
1626          *      r19:    fault vector number (e.g., 24 for General Exception)
1627          *      r31:    contains saved predicates (pr)
1628          */
1629         SAVE_MIN_WITH_COVER_R19
1630         alloc r14=ar.pfs,0,0,5,0
1631         MOV_FROM_ISR(out1)
1632         MOV_FROM_IFA(out2)
1633         MOV_FROM_IIM(out3)
1634         MOV_FROM_ITIR(out4)
1635         ;;
1636         SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(r3, out0)
1637                                                 // guarantee that interruption collection is on
1638         mov out0=r15
1639         ;;
1640         SSM_PSR_I(p15, p15, r3)                 // restore psr.i
1641         adds r3=8,r2                            // set up second base pointer for SAVE_REST
1642         ;;
1643         SAVE_REST
1644         movl r14=ia64_leave_kernel
1645         ;;
1646         mov rp=r14
1647         br.call.sptk.many b6=ia64_fault
1648 END(dispatch_to_fault_handler)
1650         /*
1651          * Squatting in this space ...
1652          *
1653          * This special case dispatcher for illegal operation faults allows preserved
1654          * registers to be modified through a callback function (asm only) that is handed
1655          * back from the fault handler in r8. Up to three arguments can be passed to the
1656          * callback function by returning an aggregate with the callback as its first
1657          * element, followed by the arguments.
1658          */
1659 ENTRY(dispatch_illegal_op_fault)
1660         .prologue
1661         .body
1662         SAVE_MIN_WITH_COVER
1663         SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(r3, r24)
1664                                 // guarantee that interruption collection is on
1665         ;;
1666         SSM_PSR_I(p15, p15, r3) // restore psr.i
1667         adds r3=8,r2    // set up second base pointer for SAVE_REST
1668         ;;
1669         alloc r14=ar.pfs,0,0,1,0        // must be first in insn group
1670         mov out0=ar.ec
1671         ;;
1672         SAVE_REST
1673         PT_REGS_UNWIND_INFO(0)
1674         ;;
1675         br.call.sptk.many rp=ia64_illegal_op_fault
1676 .ret0:  ;;
1677         alloc r14=ar.pfs,0,0,3,0        // must be first in insn group
1678         mov out0=r9
1679         mov out1=r10
1680         mov out2=r11
1681         movl r15=ia64_leave_kernel
1682         ;;
1683         mov rp=r15
1684         mov b6=r8
1685         ;;
1686         cmp.ne p6,p0=0,r8
1687 (p6)    br.call.dpnt.many b6=b6         // call returns to ia64_leave_kernel
1688         br.sptk.many ia64_leave_kernel
1689 END(dispatch_illegal_op_fault)