| blob | 522a677e050d757d9d19afb663b3adeda02245a1 |
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SPARC64_TSB_H
3 #define _SPARC64_TSB_H
5 /* The sparc64 TSB is similar to the powerpc hashtables. It's a
6 * power-of-2 sized table of TAG/PTE pairs. The cpu precomputes
7 * pointers into this table for 8K and 64K page sizes, and also a
8 * comparison TAG based upon the virtual address and context which
9 * faults.
10 *
11 * TLB miss trap handler software does the actual lookup via something
12 * of the form:
13 *
14 * ldxa [%g0] ASI_{D,I}MMU_TSB_8KB_PTR, %g1
15 * ldxa [%g0] ASI_{D,I}MMU, %g6
16 * sllx %g6, 22, %g6
17 * srlx %g6, 22, %g6
18 * ldda [%g1] ASI_NUCLEUS_QUAD_LDD, %g4
19 * cmp %g4, %g6
20 * bne,pn %xcc, tsb_miss_{d,i}tlb
21 * mov FAULT_CODE_{D,I}TLB, %g3
22 * stxa %g5, [%g0] ASI_{D,I}TLB_DATA_IN
23 * retry
24 *
25 *
26 * Each 16-byte slot of the TSB is the 8-byte tag and then the 8-byte
27 * PTE. The TAG is of the same layout as the TLB TAG TARGET mmu
28 * register which is:
29 *
30 * -------------------------------------------------
31 * | - | CONTEXT | - | VADDR bits 63:22 |
32 * -------------------------------------------------
33 * 63 61 60 48 47 42 41 0
34 *
35 * But actually, since we use per-mm TSB's, we zero out the CONTEXT
36 * field.
37 *
38 * Like the powerpc hashtables we need to use locking in order to
39 * synchronize while we update the entries. PTE updates need locking
40 * as well.
41 *
42 * We need to carefully choose a lock bits for the TSB entry. We
43 * choose to use bit 47 in the tag. Also, since we never map anything
44 * at page zero in context zero, we use zero as an invalid tag entry.
45 * When the lock bit is set, this forces a tag comparison failure.
46 */
48 #define TSB_TAG_LOCK_BIT 47
49 #define TSB_TAG_LOCK_HIGH (1 << (TSB_TAG_LOCK_BIT - 32))
51 #define TSB_TAG_INVALID_BIT 46
52 #define TSB_TAG_INVALID_HIGH (1 << (TSB_TAG_INVALID_BIT - 32))
54 /* Some cpus support physical address quad loads. We want to use
55 * those if possible so we don't need to hard-lock the TSB mapping
56 * into the TLB. We encode some instruction patching in order to
57 * support this.
58 *
59 * The kernel TSB is locked into the TLB by virtue of being in the
60 * kernel image, so we don't play these games for swapper_tsb access.
61 */
62 #ifndef __ASSEMBLY__
67 };
69 __tsb_ldquad_phys_patch_end;
74 };
76 #endif
77 #define TSB_LOAD_QUAD(TSB, REG) \
78 661: ldda [TSB] ASI_NUCLEUS_QUAD_LDD, REG; \
80 .word 661b; \
81 ldda [TSB] ASI_QUAD_LDD_PHYS, REG; \
82 ldda [TSB] ASI_QUAD_LDD_PHYS_4V, REG; \
83 .previous
85 #define TSB_LOAD_TAG_HIGH(TSB, REG) \
86 661: lduwa [TSB] ASI_N, REG; \
88 .word 661b; \
89 lduwa [TSB] ASI_PHYS_USE_EC, REG; \
90 .previous
92 #define TSB_LOAD_TAG(TSB, REG) \
93 661: ldxa [TSB] ASI_N, REG; \
95 .word 661b; \
96 ldxa [TSB] ASI_PHYS_USE_EC, REG; \
97 .previous
99 #define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \
100 661: casa [TSB] ASI_N, REG1, REG2; \
102 .word 661b; \
103 casa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
104 .previous
106 #define TSB_CAS_TAG(TSB, REG1, REG2) \
107 661: casxa [TSB] ASI_N, REG1, REG2; \
109 .word 661b; \
110 casxa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
111 .previous
113 #define TSB_STORE(ADDR, VAL) \
114 661: stxa VAL, [ADDR] ASI_N; \
116 .word 661b; \
117 stxa VAL, [ADDR] ASI_PHYS_USE_EC; \
118 .previous
120 #define TSB_LOCK_TAG(TSB, REG1, REG2) \
121 99: TSB_LOAD_TAG_HIGH(TSB, REG1); \
122 sethi %hi(TSB_TAG_LOCK_HIGH), REG2;\
123 andcc REG1, REG2, %g0; \
124 bne,pn %icc, 99b; \
125 nop; \
126 TSB_CAS_TAG_HIGH(TSB, REG1, REG2); \
127 cmp REG1, REG2; \
128 bne,pn %icc, 99b; \
129 nop; \
131 #define TSB_WRITE(TSB, TTE, TAG) \
132 add TSB, 0x8, TSB; \
133 TSB_STORE(TSB, TTE); \
134 sub TSB, 0x8, TSB; \
135 TSB_STORE(TSB, TAG);
137 /* Do a kernel page table walk. Leaves valid PTE value in
138 * REG1. Jumps to FAIL_LABEL on early page table walk
139 * termination. VADDR will not be clobbered, but REG2 will.
140 *
141 * There are two masks we must apply to propagate bits from
142 * the virtual address into the PTE physical address field
143 * when dealing with huge pages. This is because the page
144 * table boundaries do not match the huge page size(s) the
145 * hardware supports.
146 *
147 * In these cases we propagate the bits that are below the
148 * page table level where we saw the huge page mapping, but
149 * are still within the relevant physical bits for the huge
150 * page size in question. So for PMD mappings (which fall on
151 * bit 23, for 8MB per PMD) we must propagate bit 22 for a
152 * 4MB huge page. For huge PUDs (which fall on bit 33, for
153 * 8GB per PUD), we have to accommodate 256MB and 2GB huge
154 * pages. So for those we propagate bits 32 to 28.
155 */
156 #define KERN_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL) \
157 sethi %hi(swapper_pg_dir), REG1; \
158 or REG1, %lo(swapper_pg_dir), REG1; \
159 sllx VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
160 srlx REG2, 64 - PAGE_SHIFT, REG2; \
161 andn REG2, 0x7, REG2; \
162 ldx [REG1 + REG2], REG1; \
163 brz,pn REG1, FAIL_LABEL; \
164 sllx VADDR, 64 - (PUD_SHIFT + PUD_BITS), REG2; \
165 srlx REG2, 64 - PAGE_SHIFT, REG2; \
166 andn REG2, 0x7, REG2; \
167 ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
168 brz,pn REG1, FAIL_LABEL; \
169 sethi %uhi(_PAGE_PUD_HUGE), REG2; \
170 brz,pn REG1, FAIL_LABEL; \
171 sllx REG2, 32, REG2; \
172 andcc REG1, REG2, %g0; \
173 sethi %hi(0xf8000000), REG2; \
174 bne,pt %xcc, 697f; \
175 sllx REG2, 1, REG2; \
176 sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
177 srlx REG2, 64 - PAGE_SHIFT, REG2; \
178 andn REG2, 0x7, REG2; \
179 ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
180 sethi %uhi(_PAGE_PMD_HUGE), REG2; \
181 brz,pn REG1, FAIL_LABEL; \
182 sllx REG2, 32, REG2; \
183 andcc REG1, REG2, %g0; \
184 be,pn %xcc, 698f; \
185 sethi %hi(0x400000), REG2; \
186 697: brgez,pn REG1, FAIL_LABEL; \
187 andn REG1, REG2, REG1; \
188 and VADDR, REG2, REG2; \
189 ba,pt %xcc, 699f; \
190 or REG1, REG2, REG1; \
191 698: sllx VADDR, 64 - PMD_SHIFT, REG2; \
192 srlx REG2, 64 - PAGE_SHIFT, REG2; \
193 andn REG2, 0x7, REG2; \
194 ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
195 brgez,pn REG1, FAIL_LABEL; \
196 nop; \
197 699:
199 /* PUD has been loaded into REG1, interpret the value, seeing
200 * if it is a HUGE PUD or a normal one. If it is not valid
201 * then jump to FAIL_LABEL. If it is a HUGE PUD, and it
202 * translates to a valid PTE, branch to PTE_LABEL.
203 *
204 * We have to propagate bits [32:22] from the virtual address
205 * to resolve at 4M granularity.
206 */
207 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
208 #define USER_PGTABLE_CHECK_PUD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
209 700: ba 700f; \
210 nop; \
212 .word 700b; \
213 nop; \
214 .previous; \
215 brz,pn REG1, FAIL_LABEL; \
216 sethi %uhi(_PAGE_PUD_HUGE), REG2; \
217 sllx REG2, 32, REG2; \
218 andcc REG1, REG2, %g0; \
219 be,pt %xcc, 700f; \
220 sethi %hi(0xffe00000), REG2; \
221 sllx REG2, 1, REG2; \
222 brgez,pn REG1, FAIL_LABEL; \
223 andn REG1, REG2, REG1; \
224 and VADDR, REG2, REG2; \
225 brlz,pt REG1, PTE_LABEL; \
226 or REG1, REG2, REG1; \
227 700:
228 #else
229 #define USER_PGTABLE_CHECK_PUD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
230 brz,pn REG1, FAIL_LABEL; \
231 nop;
232 #endif
234 /* PMD has been loaded into REG1, interpret the value, seeing
235 * if it is a HUGE PMD or a normal one. If it is not valid
236 * then jump to FAIL_LABEL. If it is a HUGE PMD, and it
237 * translates to a valid PTE, branch to PTE_LABEL.
238 *
239 * We have to propagate the 4MB bit of the virtual address
240 * because we are fabricating 8MB pages using 4MB hw pages.
241 */
242 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
243 #define USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
244 brz,pn REG1, FAIL_LABEL; \
245 sethi %uhi(_PAGE_PMD_HUGE), REG2; \
246 sllx REG2, 32, REG2; \
247 andcc REG1, REG2, %g0; \
248 be,pt %xcc, 700f; \
249 sethi %hi(4 * 1024 * 1024), REG2; \
250 brgez,pn REG1, FAIL_LABEL; \
251 andn REG1, REG2, REG1; \
252 and VADDR, REG2, REG2; \
253 brlz,pt REG1, PTE_LABEL; \
254 or REG1, REG2, REG1; \
255 700:
256 #else
257 #define USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
258 brz,pn REG1, FAIL_LABEL; \
259 nop;
260 #endif
262 /* Do a user page table walk in MMU globals. Leaves final,
263 * valid, PTE value in REG1. Jumps to FAIL_LABEL on early
264 * page table walk termination or if the PTE is not valid.
265 *
266 * Physical base of page tables is in PHYS_PGD which will not
267 * be modified.
268 *
269 * VADDR will not be clobbered, but REG1 and REG2 will.
270 */
271 #define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL) \
272 sllx VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
273 srlx REG2, 64 - PAGE_SHIFT, REG2; \
274 andn REG2, 0x7, REG2; \
275 ldxa [PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \
276 brz,pn REG1, FAIL_LABEL; \
277 sllx VADDR, 64 - (PUD_SHIFT + PUD_BITS), REG2; \
278 srlx REG2, 64 - PAGE_SHIFT, REG2; \
279 andn REG2, 0x7, REG2; \
280 ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
281 USER_PGTABLE_CHECK_PUD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, 800f) \
282 brz,pn REG1, FAIL_LABEL; \
283 sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
284 srlx REG2, 64 - PAGE_SHIFT, REG2; \
285 andn REG2, 0x7, REG2; \
286 ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
287 USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, 800f) \
288 sllx VADDR, 64 - PMD_SHIFT, REG2; \
289 srlx REG2, 64 - PAGE_SHIFT, REG2; \
290 andn REG2, 0x7, REG2; \
291 add REG1, REG2, REG1; \
292 ldxa [REG1] ASI_PHYS_USE_EC, REG1; \
293 brgez,pn REG1, FAIL_LABEL; \
294 nop; \
295 800:
297 /* Lookup a OBP mapping on VADDR in the prom_trans[] table at TL>0.
298 * If no entry is found, FAIL_LABEL will be branched to. On success
299 * the resulting PTE value will be left in REG1. VADDR is preserved
300 * by this routine.
301 */
302 #define OBP_TRANS_LOOKUP(VADDR, REG1, REG2, REG3, FAIL_LABEL) \
303 sethi %hi(prom_trans), REG1; \
304 or REG1, %lo(prom_trans), REG1; \
305 97: ldx [REG1 + 0x00], REG2; \
306 brz,pn REG2, FAIL_LABEL; \
307 nop; \
308 ldx [REG1 + 0x08], REG3; \
309 add REG2, REG3, REG3; \
310 cmp REG2, VADDR; \
311 bgu,pt %xcc, 98f; \
312 cmp VADDR, REG3; \
313 bgeu,pt %xcc, 98f; \
314 ldx [REG1 + 0x10], REG3; \
315 sub VADDR, REG2, REG2; \
316 ba,pt %xcc, 99f; \
317 add REG3, REG2, REG1; \
318 98: ba,pt %xcc, 97b; \
319 add REG1, (3 * 8), REG1; \
320 99:
322 /* We use a 32K TSB for the whole kernel, this allows to
323 * handle about 16MB of modules and vmalloc mappings without
324 * incurring many hash conflicts.
325 */
326 #define KERNEL_TSB_SIZE_BYTES (32 * 1024)
327 #define KERNEL_TSB_NENTRIES \
328 (KERNEL_TSB_SIZE_BYTES / 16)
329 #define KERNEL_TSB4M_NENTRIES 4096
331 /* Do a kernel TSB lookup at tl>0 on VADDR+TAG, branch to OK_LABEL
332 * on TSB hit. REG1, REG2, REG3, and REG4 are used as temporaries
333 * and the found TTE will be left in REG1. REG3 and REG4 must
334 * be an even/odd pair of registers.
335 *
336 * VADDR and TAG will be preserved and not clobbered by this macro.
337 */
338 #define KERN_TSB_LOOKUP_TL1(VADDR, TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
339 661: sethi %uhi(swapper_tsb), REG1; \
340 sethi %hi(swapper_tsb), REG2; \
341 or REG1, %ulo(swapper_tsb), REG1; \
342 or REG2, %lo(swapper_tsb), REG2; \
344 .word 661b; \
345 .previous; \
346 sllx REG1, 32, REG1; \
347 or REG1, REG2, REG1; \
348 srlx VADDR, PAGE_SHIFT, REG2; \
349 and REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \
350 sllx REG2, 4, REG2; \
351 add REG1, REG2, REG2; \
352 TSB_LOAD_QUAD(REG2, REG3); \
353 cmp REG3, TAG; \
354 be,a,pt %xcc, OK_LABEL; \
355 mov REG4, REG1;
357 #ifndef CONFIG_DEBUG_PAGEALLOC
358 /* This version uses a trick, the TAG is already (VADDR >> 22) so
359 * we can make use of that for the index computation.
360 */
361 #define KERN_TSB4M_LOOKUP_TL1(TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
362 661: sethi %uhi(swapper_4m_tsb), REG1; \
363 sethi %hi(swapper_4m_tsb), REG2; \
364 or REG1, %ulo(swapper_4m_tsb), REG1; \
365 or REG2, %lo(swapper_4m_tsb), REG2; \
367 .word 661b; \
368 .previous; \
369 sllx REG1, 32, REG1; \
370 or REG1, REG2, REG1; \
371 and TAG, (KERNEL_TSB4M_NENTRIES - 1), REG2; \
372 sllx REG2, 4, REG2; \
373 add REG1, REG2, REG2; \
374 TSB_LOAD_QUAD(REG2, REG3); \
375 cmp REG3, TAG; \
376 be,a,pt %xcc, OK_LABEL; \
377 mov REG4, REG1;
378 #endif