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/* Some cpus support physical address quad loads.  We want to use
54 * those if possible so we don't need to hard-lock the TSB mapping
55 * into the TLB.  We encode some instruction patching in order to
56 * support this.
57 *
58 * The kernel TSB is locked into the TLB by virtue of being in the
59 * kernel image, so we don't play these games for swapper_tsb access.
60 */
61#ifndef __ASSEMBLY__
62struct tsb_ldquad_phys_patch_entry {
63	unsigned int	addr;
64	unsigned int	sun4u_insn;
65	unsigned int	sun4v_insn;
66};
67extern struct tsb_ldquad_phys_patch_entry __tsb_ldquad_phys_patch,
68	__tsb_ldquad_phys_patch_end;
69
70struct tsb_phys_patch_entry {
71	unsigned int	addr;
72	unsigned int	insn;
73};
74extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
75#endif
76#define TSB_LOAD_QUAD(TSB, REG)	\
77661:	ldda		[TSB] ASI_NUCLEUS_QUAD_LDD, REG; \
78	.section	.tsb_ldquad_phys_patch, "ax"; \
79	.word		661b; \
80	ldda		[TSB] ASI_QUAD_LDD_PHYS, REG; \
81	ldda		[TSB] ASI_QUAD_LDD_PHYS_4V, REG; \
82	.previous
83
84#define TSB_LOAD_TAG_HIGH(TSB, REG) \
85661:	lduwa		[TSB] ASI_N, REG; \
86	.section	.tsb_phys_patch, "ax"; \
87	.word		661b; \
88	lduwa		[TSB] ASI_PHYS_USE_EC, REG; \
89	.previous
90
91#define TSB_LOAD_TAG(TSB, REG) \
92661:	ldxa		[TSB] ASI_N, REG; \
93	.section	.tsb_phys_patch, "ax"; \
94	.word		661b; \
95	ldxa		[TSB] ASI_PHYS_USE_EC, REG; \
96	.previous
97
98#define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \
99661:	casa		[TSB] ASI_N, REG1, REG2; \
100	.section	.tsb_phys_patch, "ax"; \
101	.word		661b; \
102	casa		[TSB] ASI_PHYS_USE_EC, REG1, REG2; \
103	.previous
104
105#define TSB_CAS_TAG(TSB, REG1, REG2) \
106661:	casxa		[TSB] ASI_N, REG1, REG2; \
107	.section	.tsb_phys_patch, "ax"; \
108	.word		661b; \
109	casxa		[TSB] ASI_PHYS_USE_EC, REG1, REG2; \
110	.previous
111
112#define TSB_STORE(ADDR, VAL) \
113661:	stxa		VAL, [ADDR] ASI_N; \
114	.section	.tsb_phys_patch, "ax"; \
115	.word		661b; \
116	stxa		VAL, [ADDR] ASI_PHYS_USE_EC; \
117	.previous
118
119#define TSB_LOCK_TAG(TSB, REG1, REG2)	\
12099:	TSB_LOAD_TAG_HIGH(TSB, REG1);	\
121	sethi	%hi(TSB_TAG_LOCK_HIGH), REG2;\
122	andcc	REG1, REG2, %g0;	\
123	bne,pn	%icc, 99b;		\
124	 nop;				\
125	TSB_CAS_TAG_HIGH(TSB, REG1, REG2);	\
126	cmp	REG1, REG2;		\
127	bne,pn	%icc, 99b;		\
128	 nop;				\
129
130#define TSB_WRITE(TSB, TTE, TAG) \
131	add	TSB, 0x8, TSB;   \
132	TSB_STORE(TSB, TTE);     \
133	sub	TSB, 0x8, TSB;   \
134	TSB_STORE(TSB, TAG);
135
136	/* Do a kernel page table walk.  Leaves valid PTE value in
137	 * REG1.  Jumps to FAIL_LABEL on early page table walk
138	 * termination.  VADDR will not be clobbered, but REG2 will.
139	 *
140	 * There are two masks we must apply to propagate bits from
141	 * the virtual address into the PTE physical address field
142	 * when dealing with huge pages.  This is because the page
143	 * table boundaries do not match the huge page size(s) the
144	 * hardware supports.
145	 *
146	 * In these cases we propagate the bits that are below the
147	 * page table level where we saw the huge page mapping, but
148	 * are still within the relevant physical bits for the huge
149	 * page size in question.  So for PMD mappings (which fall on
150	 * bit 23, for 8MB per PMD) we must propagate bit 22 for a
151	 * 4MB huge page.  For huge PUDs (which fall on bit 33, for
152	 * 8GB per PUD), we have to accomodate 256MB and 2GB huge
153	 * pages.  So for those we propagate bits 32 to 28.
154	 */
155#define KERN_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL)	\
156	sethi		%hi(swapper_pg_dir), REG1; \
157	or		REG1, %lo(swapper_pg_dir), REG1; \
158	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
159	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
160	andn		REG2, 0x7, REG2; \
161	ldx		[REG1 + REG2], REG1; \
162	brz,pn		REG1, FAIL_LABEL; \
163	 sllx		VADDR, 64 - (PUD_SHIFT + PUD_BITS), REG2; \
164	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
165	andn		REG2, 0x7, REG2; \
166	ldxa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
167	brz,pn		REG1, FAIL_LABEL; \
168	sethi		%uhi(_PAGE_PUD_HUGE), REG2; \
169	brz,pn		REG1, FAIL_LABEL; \
170	 sllx		REG2, 32, REG2; \
171	andcc		REG1, REG2, %g0; \
172	sethi		%hi(0xf8000000), REG2; \
173	bne,pt		%xcc, 697f; \
174	 sllx		REG2, 1, REG2; \
175	sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
176	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
177	andn		REG2, 0x7, REG2; \
178	ldxa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
179	sethi		%uhi(_PAGE_PMD_HUGE), REG2; \
180	brz,pn		REG1, FAIL_LABEL; \
181	 sllx		REG2, 32, REG2; \
182	andcc		REG1, REG2, %g0; \
183	be,pn		%xcc, 698f; \
184	 sethi		%hi(0x400000), REG2; \
185697:	brgez,pn	REG1, FAIL_LABEL; \
186	 andn		REG1, REG2, REG1; \
187	and		VADDR, REG2, REG2; \
188	ba,pt		%xcc, 699f; \
189	 or		REG1, REG2, REG1; \
190698:	sllx		VADDR, 64 - PMD_SHIFT, REG2; \
191	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
192	andn		REG2, 0x7, REG2; \
193	ldxa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
194	brgez,pn	REG1, FAIL_LABEL; \
195	 nop; \
196699:
197
198	/* PMD has been loaded into REG1, interpret the value, seeing
199	 * if it is a HUGE PMD or a normal one.  If it is not valid
200	 * then jump to FAIL_LABEL.  If it is a HUGE PMD, and it
201	 * translates to a valid PTE, branch to PTE_LABEL.
202	 *
203	 * We have to propagate the 4MB bit of the virtual address
204	 * because we are fabricating 8MB pages using 4MB hw pages.
205	 */
206#ifdef CONFIG_TRANSPARENT_HUGEPAGE
207#define USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
208	brz,pn		REG1, FAIL_LABEL;		\
209	 sethi		%uhi(_PAGE_PMD_HUGE), REG2;	\
210	sllx		REG2, 32, REG2;			\
211	andcc		REG1, REG2, %g0;		\
212	be,pt		%xcc, 700f;			\
213	 sethi		%hi(4 * 1024 * 1024), REG2;	\
214	brgez,pn	REG1, FAIL_LABEL;		\
215	 andn		REG1, REG2, REG1;		\
216	and		VADDR, REG2, REG2;		\
217	brlz,pt		REG1, PTE_LABEL;		\
218	 or		REG1, REG2, REG1;		\
219700:
220#else
221#define USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
222	brz,pn		REG1, FAIL_LABEL; \
223	 nop;
224#endif
225
226	/* Do a user page table walk in MMU globals.  Leaves final,
227	 * valid, PTE value in REG1.  Jumps to FAIL_LABEL on early
228	 * page table walk termination or if the PTE is not valid.
229	 *
230	 * Physical base of page tables is in PHYS_PGD which will not
231	 * be modified.
232	 *
233	 * VADDR will not be clobbered, but REG1 and REG2 will.
234	 */
235#define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL)	\
236	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
237	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
238	andn		REG2, 0x7, REG2; \
239	ldxa		[PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \
240	brz,pn		REG1, FAIL_LABEL; \
241	 sllx		VADDR, 64 - (PUD_SHIFT + PUD_BITS), REG2; \
242	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
243	andn		REG2, 0x7, REG2; \
244	ldxa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
245	brz,pn		REG1, FAIL_LABEL; \
246	 sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
247	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
248	andn		REG2, 0x7, REG2; \
249	ldxa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
250	USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, 800f) \
251	sllx		VADDR, 64 - PMD_SHIFT, REG2; \
252	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
253	andn		REG2, 0x7, REG2; \
254	add		REG1, REG2, REG1; \
255	ldxa		[REG1] ASI_PHYS_USE_EC, REG1; \
256	brgez,pn	REG1, FAIL_LABEL; \
257	 nop; \
258800:
259
260/* Lookup a OBP mapping on VADDR in the prom_trans[] table at TL>0.
261 * If no entry is found, FAIL_LABEL will be branched to.  On success
262 * the resulting PTE value will be left in REG1.  VADDR is preserved
263 * by this routine.
264 */
265#define OBP_TRANS_LOOKUP(VADDR, REG1, REG2, REG3, FAIL_LABEL) \
266	sethi		%hi(prom_trans), REG1; \
267	or		REG1, %lo(prom_trans), REG1; \
26897:	ldx		[REG1 + 0x00], REG2; \
269	brz,pn		REG2, FAIL_LABEL; \
270	 nop; \
271	ldx		[REG1 + 0x08], REG3; \
272	add		REG2, REG3, REG3; \
273	cmp		REG2, VADDR; \
274	bgu,pt		%xcc, 98f; \
275	 cmp		VADDR, REG3; \
276	bgeu,pt		%xcc, 98f; \
277	 ldx		[REG1 + 0x10], REG3; \
278	sub		VADDR, REG2, REG2; \
279	ba,pt		%xcc, 99f; \
280	 add		REG3, REG2, REG1; \
28198:	ba,pt		%xcc, 97b; \
282	 add		REG1, (3 * 8), REG1; \
28399:
284
285	/* We use a 32K TSB for the whole kernel, this allows to
286	 * handle about 16MB of modules and vmalloc mappings without
287	 * incurring many hash conflicts.
288	 */
289#define KERNEL_TSB_SIZE_BYTES	(32 * 1024)
290#define KERNEL_TSB_NENTRIES	\
291	(KERNEL_TSB_SIZE_BYTES / 16)
292#define KERNEL_TSB4M_NENTRIES	4096
293
294	/* Do a kernel TSB lookup at tl>0 on VADDR+TAG, branch to OK_LABEL
295	 * on TSB hit.  REG1, REG2, REG3, and REG4 are used as temporaries
296	 * and the found TTE will be left in REG1.  REG3 and REG4 must
297	 * be an even/odd pair of registers.
298	 *
299	 * VADDR and TAG will be preserved and not clobbered by this macro.
300	 */
301#define KERN_TSB_LOOKUP_TL1(VADDR, TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
302661:	sethi		%uhi(swapper_tsb), REG1; \
303	sethi		%hi(swapper_tsb), REG2; \
304	or		REG1, %ulo(swapper_tsb), REG1; \
305	or		REG2, %lo(swapper_tsb), REG2; \
306	.section	.swapper_tsb_phys_patch, "ax"; \
307	.word		661b; \
308	.previous; \
309	sllx		REG1, 32, REG1; \
310	or		REG1, REG2, REG1; \
311	srlx		VADDR, PAGE_SHIFT, REG2; \
312	and		REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \
313	sllx		REG2, 4, REG2; \
314	add		REG1, REG2, REG2; \
315	TSB_LOAD_QUAD(REG2, REG3); \
316	cmp		REG3, TAG; \
317	be,a,pt		%xcc, OK_LABEL; \
318	 mov		REG4, REG1;
319
320#ifndef CONFIG_DEBUG_PAGEALLOC
321	/* This version uses a trick, the TAG is already (VADDR >> 22) so
322	 * we can make use of that for the index computation.
323	 */
324#define KERN_TSB4M_LOOKUP_TL1(TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
325661:	sethi		%uhi(swapper_4m_tsb), REG1; \
326	sethi		%hi(swapper_4m_tsb), REG2; \
327	or		REG1, %ulo(swapper_4m_tsb), REG1; \
328	or		REG2, %lo(swapper_4m_tsb), REG2; \
329	.section	.swapper_4m_tsb_phys_patch, "ax"; \
330	.word		661b; \
331	.previous; \
332	sllx		REG1, 32, REG1; \
333	or		REG1, REG2, REG1; \
334	and		TAG, (KERNEL_TSB4M_NENTRIES - 1), REG2; \
335	sllx		REG2, 4, REG2; \
336	add		REG1, REG2, REG2; \
337	TSB_LOAD_QUAD(REG2, REG3); \
338	cmp		REG3, TAG; \
339	be,a,pt		%xcc, OK_LABEL; \
340	 mov		REG4, REG1;
341#endif
342
343#endif /* !(_SPARC64_TSB_H) */
344