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-rw-r--r--arch/sparc/include/asm/tsb.h283
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diff --git a/arch/sparc/include/asm/tsb.h b/arch/sparc/include/asm/tsb.h
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1#ifndef _SPARC64_TSB_H
2#define _SPARC64_TSB_H
3
4/* The sparc64 TSB is similar to the powerpc hashtables. It's a
5 * power-of-2 sized table of TAG/PTE pairs. The cpu precomputes
6 * pointers into this table for 8K and 64K page sizes, and also a
7 * comparison TAG based upon the virtual address and context which
8 * faults.
9 *
10 * TLB miss trap handler software does the actual lookup via something
11 * of the form:
12 *
13 * ldxa [%g0] ASI_{D,I}MMU_TSB_8KB_PTR, %g1
14 * ldxa [%g0] ASI_{D,I}MMU, %g6
15 * sllx %g6, 22, %g6
16 * srlx %g6, 22, %g6
17 * ldda [%g1] ASI_NUCLEUS_QUAD_LDD, %g4
18 * cmp %g4, %g6
19 * bne,pn %xcc, tsb_miss_{d,i}tlb
20 * mov FAULT_CODE_{D,I}TLB, %g3
21 * stxa %g5, [%g0] ASI_{D,I}TLB_DATA_IN
22 * retry
23 *
24 *
25 * Each 16-byte slot of the TSB is the 8-byte tag and then the 8-byte
26 * PTE. The TAG is of the same layout as the TLB TAG TARGET mmu
27 * register which is:
28 *
29 * -------------------------------------------------
30 * | - | CONTEXT | - | VADDR bits 63:22 |
31 * -------------------------------------------------
32 * 63 61 60 48 47 42 41 0
33 *
34 * But actually, since we use per-mm TSB's, we zero out the CONTEXT
35 * field.
36 *
37 * Like the powerpc hashtables we need to use locking in order to
38 * synchronize while we update the entries. PTE updates need locking
39 * as well.
40 *
41 * We need to carefully choose a lock bits for the TSB entry. We
42 * choose to use bit 47 in the tag. Also, since we never map anything
43 * at page zero in context zero, we use zero as an invalid tag entry.
44 * When the lock bit is set, this forces a tag comparison failure.
45 */
46
47#define TSB_TAG_LOCK_BIT 47
48#define TSB_TAG_LOCK_HIGH (1 << (TSB_TAG_LOCK_BIT - 32))
49
50#define TSB_TAG_INVALID_BIT 46
51#define TSB_TAG_INVALID_HIGH (1 << (TSB_TAG_INVALID_BIT - 32))
52
53#define TSB_MEMBAR membar #StoreStore
54
55/* Some cpus support physical address quad loads. We want to use
56 * those if possible so we don't need to hard-lock the TSB mapping
57 * into the TLB. We encode some instruction patching in order to
58 * support this.
59 *
60 * The kernel TSB is locked into the TLB by virtue of being in the
61 * kernel image, so we don't play these games for swapper_tsb access.
62 */
63#ifndef __ASSEMBLY__
64struct tsb_ldquad_phys_patch_entry {
65 unsigned int addr;
66 unsigned int sun4u_insn;
67 unsigned int sun4v_insn;
68};
69extern struct tsb_ldquad_phys_patch_entry __tsb_ldquad_phys_patch,
70 __tsb_ldquad_phys_patch_end;
71
72struct tsb_phys_patch_entry {
73 unsigned int addr;
74 unsigned int insn;
75};
76extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
77#endif
78#define TSB_LOAD_QUAD(TSB, REG) \
79661: ldda [TSB] ASI_NUCLEUS_QUAD_LDD, REG; \
80 .section .tsb_ldquad_phys_patch, "ax"; \
81 .word 661b; \
82 ldda [TSB] ASI_QUAD_LDD_PHYS, REG; \
83 ldda [TSB] ASI_QUAD_LDD_PHYS_4V, REG; \
84 .previous
85
86#define TSB_LOAD_TAG_HIGH(TSB, REG) \
87661: lduwa [TSB] ASI_N, REG; \
88 .section .tsb_phys_patch, "ax"; \
89 .word 661b; \
90 lduwa [TSB] ASI_PHYS_USE_EC, REG; \
91 .previous
92
93#define TSB_LOAD_TAG(TSB, REG) \
94661: ldxa [TSB] ASI_N, REG; \
95 .section .tsb_phys_patch, "ax"; \
96 .word 661b; \
97 ldxa [TSB] ASI_PHYS_USE_EC, REG; \
98 .previous
99
100#define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \
101661: casa [TSB] ASI_N, REG1, REG2; \
102 .section .tsb_phys_patch, "ax"; \
103 .word 661b; \
104 casa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
105 .previous
106
107#define TSB_CAS_TAG(TSB, REG1, REG2) \
108661: casxa [TSB] ASI_N, REG1, REG2; \
109 .section .tsb_phys_patch, "ax"; \
110 .word 661b; \
111 casxa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
112 .previous
113
114#define TSB_STORE(ADDR, VAL) \
115661: stxa VAL, [ADDR] ASI_N; \
116 .section .tsb_phys_patch, "ax"; \
117 .word 661b; \
118 stxa VAL, [ADDR] ASI_PHYS_USE_EC; \
119 .previous
120
121#define TSB_LOCK_TAG(TSB, REG1, REG2) \
12299: TSB_LOAD_TAG_HIGH(TSB, REG1); \
123 sethi %hi(TSB_TAG_LOCK_HIGH), REG2;\
124 andcc REG1, REG2, %g0; \
125 bne,pn %icc, 99b; \
126 nop; \
127 TSB_CAS_TAG_HIGH(TSB, REG1, REG2); \
128 cmp REG1, REG2; \
129 bne,pn %icc, 99b; \
130 nop; \
131 TSB_MEMBAR
132
133#define TSB_WRITE(TSB, TTE, TAG) \
134 add TSB, 0x8, TSB; \
135 TSB_STORE(TSB, TTE); \
136 sub TSB, 0x8, TSB; \
137 TSB_MEMBAR; \
138 TSB_STORE(TSB, TAG);
139
140#define KTSB_LOAD_QUAD(TSB, REG) \
141 ldda [TSB] ASI_NUCLEUS_QUAD_LDD, REG;
142
143#define KTSB_STORE(ADDR, VAL) \
144 stxa VAL, [ADDR] ASI_N;
145
146#define KTSB_LOCK_TAG(TSB, REG1, REG2) \
14799: lduwa [TSB] ASI_N, REG1; \
148 sethi %hi(TSB_TAG_LOCK_HIGH), REG2;\
149 andcc REG1, REG2, %g0; \
150 bne,pn %icc, 99b; \
151 nop; \
152 casa [TSB] ASI_N, REG1, REG2;\
153 cmp REG1, REG2; \
154 bne,pn %icc, 99b; \
155 nop; \
156 TSB_MEMBAR
157
158#define KTSB_WRITE(TSB, TTE, TAG) \
159 add TSB, 0x8, TSB; \
160 stxa TTE, [TSB] ASI_N; \
161 sub TSB, 0x8, TSB; \
162 TSB_MEMBAR; \
163 stxa TAG, [TSB] ASI_N;
164
165 /* Do a kernel page table walk. Leaves physical PTE pointer in
166 * REG1. Jumps to FAIL_LABEL on early page table walk termination.
167 * VADDR will not be clobbered, but REG2 will.
168 */
169#define KERN_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL) \
170 sethi %hi(swapper_pg_dir), REG1; \
171 or REG1, %lo(swapper_pg_dir), REG1; \
172 sllx VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
173 srlx REG2, 64 - PAGE_SHIFT, REG2; \
174 andn REG2, 0x3, REG2; \
175 lduw [REG1 + REG2], REG1; \
176 brz,pn REG1, FAIL_LABEL; \
177 sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
178 srlx REG2, 64 - PAGE_SHIFT, REG2; \
179 sllx REG1, 11, REG1; \
180 andn REG2, 0x3, REG2; \
181 lduwa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
182 brz,pn REG1, FAIL_LABEL; \
183 sllx VADDR, 64 - PMD_SHIFT, REG2; \
184 srlx REG2, 64 - PAGE_SHIFT, REG2; \
185 sllx REG1, 11, REG1; \
186 andn REG2, 0x7, REG2; \
187 add REG1, REG2, REG1;
188
189 /* Do a user page table walk in MMU globals. Leaves physical PTE
190 * pointer in REG1. Jumps to FAIL_LABEL on early page table walk
191 * termination. Physical base of page tables is in PHYS_PGD which
192 * will not be modified.
193 *
194 * VADDR will not be clobbered, but REG1 and REG2 will.
195 */
196#define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL) \
197 sllx VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
198 srlx REG2, 64 - PAGE_SHIFT, REG2; \
199 andn REG2, 0x3, REG2; \
200 lduwa [PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \
201 brz,pn REG1, FAIL_LABEL; \
202 sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
203 srlx REG2, 64 - PAGE_SHIFT, REG2; \
204 sllx REG1, 11, REG1; \
205 andn REG2, 0x3, REG2; \
206 lduwa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
207 brz,pn REG1, FAIL_LABEL; \
208 sllx VADDR, 64 - PMD_SHIFT, REG2; \
209 srlx REG2, 64 - PAGE_SHIFT, REG2; \
210 sllx REG1, 11, REG1; \
211 andn REG2, 0x7, REG2; \
212 add REG1, REG2, REG1;
213
214/* Lookup a OBP mapping on VADDR in the prom_trans[] table at TL>0.
215 * If no entry is found, FAIL_LABEL will be branched to. On success
216 * the resulting PTE value will be left in REG1. VADDR is preserved
217 * by this routine.
218 */
219#define OBP_TRANS_LOOKUP(VADDR, REG1, REG2, REG3, FAIL_LABEL) \
220 sethi %hi(prom_trans), REG1; \
221 or REG1, %lo(prom_trans), REG1; \
22297: ldx [REG1 + 0x00], REG2; \
223 brz,pn REG2, FAIL_LABEL; \
224 nop; \
225 ldx [REG1 + 0x08], REG3; \
226 add REG2, REG3, REG3; \
227 cmp REG2, VADDR; \
228 bgu,pt %xcc, 98f; \
229 cmp VADDR, REG3; \
230 bgeu,pt %xcc, 98f; \
231 ldx [REG1 + 0x10], REG3; \
232 sub VADDR, REG2, REG2; \
233 ba,pt %xcc, 99f; \
234 add REG3, REG2, REG1; \
23598: ba,pt %xcc, 97b; \
236 add REG1, (3 * 8), REG1; \
23799:
238
239 /* We use a 32K TSB for the whole kernel, this allows to
240 * handle about 16MB of modules and vmalloc mappings without
241 * incurring many hash conflicts.
242 */
243#define KERNEL_TSB_SIZE_BYTES (32 * 1024)
244#define KERNEL_TSB_NENTRIES \
245 (KERNEL_TSB_SIZE_BYTES / 16)
246#define KERNEL_TSB4M_NENTRIES 4096
247
248 /* Do a kernel TSB lookup at tl>0 on VADDR+TAG, branch to OK_LABEL
249 * on TSB hit. REG1, REG2, REG3, and REG4 are used as temporaries
250 * and the found TTE will be left in REG1. REG3 and REG4 must
251 * be an even/odd pair of registers.
252 *
253 * VADDR and TAG will be preserved and not clobbered by this macro.
254 */
255#define KERN_TSB_LOOKUP_TL1(VADDR, TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
256 sethi %hi(swapper_tsb), REG1; \
257 or REG1, %lo(swapper_tsb), REG1; \
258 srlx VADDR, PAGE_SHIFT, REG2; \
259 and REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \
260 sllx REG2, 4, REG2; \
261 add REG1, REG2, REG2; \
262 KTSB_LOAD_QUAD(REG2, REG3); \
263 cmp REG3, TAG; \
264 be,a,pt %xcc, OK_LABEL; \
265 mov REG4, REG1;
266
267#ifndef CONFIG_DEBUG_PAGEALLOC
268 /* This version uses a trick, the TAG is already (VADDR >> 22) so
269 * we can make use of that for the index computation.
270 */
271#define KERN_TSB4M_LOOKUP_TL1(TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
272 sethi %hi(swapper_4m_tsb), REG1; \
273 or REG1, %lo(swapper_4m_tsb), REG1; \
274 and TAG, (KERNEL_TSB4M_NENTRIES - 1), REG2; \
275 sllx REG2, 4, REG2; \
276 add REG1, REG2, REG2; \
277 KTSB_LOAD_QUAD(REG2, REG3); \
278 cmp REG3, TAG; \
279 be,a,pt %xcc, OK_LABEL; \
280 mov REG4, REG1;
281#endif
282
283#endif /* !(_SPARC64_TSB_H) */
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-05 14:49:24 -0500