xref: /linux/arch/mips/mm/tlbex.c (revision bd45ac0c5daae35e7c71138172e63df5cf644cf6)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Synthesize TLB refill handlers at runtime.
7  *
8  * Copyright (C) 2004,2005,2006 by Thiemo Seufer
9  * Copyright (C) 2005, 2007  Maciej W. Rozycki
10  * Copyright (C) 2006  Ralf Baechle (ralf@linux-mips.org)
11  *
12  * ... and the days got worse and worse and now you see
13  * I've gone completly out of my mind.
14  *
15  * They're coming to take me a away haha
16  * they're coming to take me a away hoho hihi haha
17  * to the funny farm where code is beautiful all the time ...
18  *
19  * (Condolences to Napoleon XIV)
20  */
21 
22 #include <linux/kernel.h>
23 #include <linux/types.h>
24 #include <linux/string.h>
25 #include <linux/init.h>
26 
27 #include <asm/bugs.h>
28 #include <asm/mmu_context.h>
29 #include <asm/inst.h>
30 #include <asm/elf.h>
31 #include <asm/war.h>
32 
33 static inline int r45k_bvahwbug(void)
34 {
35 	/* XXX: We should probe for the presence of this bug, but we don't. */
36 	return 0;
37 }
38 
39 static inline int r4k_250MHZhwbug(void)
40 {
41 	/* XXX: We should probe for the presence of this bug, but we don't. */
42 	return 0;
43 }
44 
45 static inline int __maybe_unused bcm1250_m3_war(void)
46 {
47 	return BCM1250_M3_WAR;
48 }
49 
50 static inline int __maybe_unused r10000_llsc_war(void)
51 {
52 	return R10000_LLSC_WAR;
53 }
54 
55 /*
56  * Found by experiment: At least some revisions of the 4kc throw under
57  * some circumstances a machine check exception, triggered by invalid
58  * values in the index register.  Delaying the tlbp instruction until
59  * after the next branch,  plus adding an additional nop in front of
60  * tlbwi/tlbwr avoids the invalid index register values. Nobody knows
61  * why; it's not an issue caused by the core RTL.
62  *
63  */
64 static int __init m4kc_tlbp_war(void)
65 {
66 	return (current_cpu_data.processor_id & 0xffff00) ==
67 	       (PRID_COMP_MIPS | PRID_IMP_4KC);
68 }
69 
70 /*
71  * A little micro-assembler, intended for TLB refill handler
72  * synthesizing. It is intentionally kept simple, does only support
73  * a subset of instructions, and does not try to hide pipeline effects
74  * like branch delay slots.
75  */
76 
77 enum fields
78 {
79 	RS = 0x001,
80 	RT = 0x002,
81 	RD = 0x004,
82 	RE = 0x008,
83 	SIMM = 0x010,
84 	UIMM = 0x020,
85 	BIMM = 0x040,
86 	JIMM = 0x080,
87 	FUNC = 0x100,
88 	SET = 0x200
89 };
90 
91 #define OP_MASK		0x3f
92 #define OP_SH		26
93 #define RS_MASK		0x1f
94 #define RS_SH		21
95 #define RT_MASK		0x1f
96 #define RT_SH		16
97 #define RD_MASK		0x1f
98 #define RD_SH		11
99 #define RE_MASK		0x1f
100 #define RE_SH		6
101 #define IMM_MASK	0xffff
102 #define IMM_SH		0
103 #define JIMM_MASK	0x3ffffff
104 #define JIMM_SH		0
105 #define FUNC_MASK	0x3f
106 #define FUNC_SH		0
107 #define SET_MASK	0x7
108 #define SET_SH		0
109 
110 enum opcode {
111 	insn_invalid,
112 	insn_addu, insn_addiu, insn_and, insn_andi, insn_beq,
113 	insn_beql, insn_bgez, insn_bgezl, insn_bltz, insn_bltzl,
114 	insn_bne, insn_daddu, insn_daddiu, insn_dmfc0, insn_dmtc0,
115 	insn_dsll, insn_dsll32, insn_dsra, insn_dsrl, insn_dsrl32,
116 	insn_dsubu, insn_eret, insn_j, insn_jal, insn_jr, insn_ld,
117 	insn_ll, insn_lld, insn_lui, insn_lw, insn_mfc0, insn_mtc0,
118 	insn_ori, insn_rfe, insn_sc, insn_scd, insn_sd, insn_sll,
119 	insn_sra, insn_srl, insn_subu, insn_sw, insn_tlbp, insn_tlbwi,
120 	insn_tlbwr, insn_xor, insn_xori
121 };
122 
123 struct insn {
124 	enum opcode opcode;
125 	u32 match;
126 	enum fields fields;
127 };
128 
129 /* This macro sets the non-variable bits of an instruction. */
130 #define M(a, b, c, d, e, f)					\
131 	((a) << OP_SH						\
132 	 | (b) << RS_SH						\
133 	 | (c) << RT_SH						\
134 	 | (d) << RD_SH						\
135 	 | (e) << RE_SH						\
136 	 | (f) << FUNC_SH)
137 
138 static struct insn insn_table[] __initdata = {
139 	{ insn_addiu, M(addiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM },
140 	{ insn_addu, M(spec_op, 0, 0, 0, 0, addu_op), RS | RT | RD },
141 	{ insn_and, M(spec_op, 0, 0, 0, 0, and_op), RS | RT | RD },
142 	{ insn_andi, M(andi_op, 0, 0, 0, 0, 0), RS | RT | UIMM },
143 	{ insn_beq, M(beq_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
144 	{ insn_beql, M(beql_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
145 	{ insn_bgez, M(bcond_op, 0, bgez_op, 0, 0, 0), RS | BIMM },
146 	{ insn_bgezl, M(bcond_op, 0, bgezl_op, 0, 0, 0), RS | BIMM },
147 	{ insn_bltz, M(bcond_op, 0, bltz_op, 0, 0, 0), RS | BIMM },
148 	{ insn_bltzl, M(bcond_op, 0, bltzl_op, 0, 0, 0), RS | BIMM },
149 	{ insn_bne, M(bne_op, 0, 0, 0, 0, 0), RS | RT | BIMM },
150 	{ insn_daddiu, M(daddiu_op, 0, 0, 0, 0, 0), RS | RT | SIMM },
151 	{ insn_daddu, M(spec_op, 0, 0, 0, 0, daddu_op), RS | RT | RD },
152 	{ insn_dmfc0, M(cop0_op, dmfc_op, 0, 0, 0, 0), RT | RD | SET},
153 	{ insn_dmtc0, M(cop0_op, dmtc_op, 0, 0, 0, 0), RT | RD | SET},
154 	{ insn_dsll, M(spec_op, 0, 0, 0, 0, dsll_op), RT | RD | RE },
155 	{ insn_dsll32, M(spec_op, 0, 0, 0, 0, dsll32_op), RT | RD | RE },
156 	{ insn_dsra, M(spec_op, 0, 0, 0, 0, dsra_op), RT | RD | RE },
157 	{ insn_dsrl, M(spec_op, 0, 0, 0, 0, dsrl_op), RT | RD | RE },
158 	{ insn_dsrl32, M(spec_op, 0, 0, 0, 0, dsrl32_op), RT | RD | RE },
159 	{ insn_dsubu, M(spec_op, 0, 0, 0, 0, dsubu_op), RS | RT | RD },
160 	{ insn_eret,  M(cop0_op, cop_op, 0, 0, 0, eret_op),  0 },
161 	{ insn_j,  M(j_op, 0, 0, 0, 0, 0),  JIMM },
162 	{ insn_jal,  M(jal_op, 0, 0, 0, 0, 0),  JIMM },
163 	{ insn_jr,  M(spec_op, 0, 0, 0, 0, jr_op),  RS },
164 	{ insn_ld,  M(ld_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
165 	{ insn_ll,  M(ll_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
166 	{ insn_lld,  M(lld_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
167 	{ insn_lui,  M(lui_op, 0, 0, 0, 0, 0),  RT | SIMM },
168 	{ insn_lw,  M(lw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
169 	{ insn_mfc0,  M(cop0_op, mfc_op, 0, 0, 0, 0),  RT | RD | SET},
170 	{ insn_mtc0,  M(cop0_op, mtc_op, 0, 0, 0, 0),  RT | RD | SET},
171 	{ insn_ori,  M(ori_op, 0, 0, 0, 0, 0),  RS | RT | UIMM },
172 	{ insn_rfe,  M(cop0_op, cop_op, 0, 0, 0, rfe_op),  0 },
173 	{ insn_sc,  M(sc_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
174 	{ insn_scd,  M(scd_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
175 	{ insn_sd,  M(sd_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
176 	{ insn_sll,  M(spec_op, 0, 0, 0, 0, sll_op),  RT | RD | RE },
177 	{ insn_sra,  M(spec_op, 0, 0, 0, 0, sra_op),  RT | RD | RE },
178 	{ insn_srl,  M(spec_op, 0, 0, 0, 0, srl_op),  RT | RD | RE },
179 	{ insn_subu,  M(spec_op, 0, 0, 0, 0, subu_op),  RS | RT | RD },
180 	{ insn_sw,  M(sw_op, 0, 0, 0, 0, 0),  RS | RT | SIMM },
181 	{ insn_tlbp,  M(cop0_op, cop_op, 0, 0, 0, tlbp_op),  0 },
182 	{ insn_tlbwi,  M(cop0_op, cop_op, 0, 0, 0, tlbwi_op),  0 },
183 	{ insn_tlbwr,  M(cop0_op, cop_op, 0, 0, 0, tlbwr_op),  0 },
184 	{ insn_xor,  M(spec_op, 0, 0, 0, 0, xor_op),  RS | RT | RD },
185 	{ insn_xori,  M(xori_op, 0, 0, 0, 0, 0),  RS | RT | UIMM },
186 	{ insn_invalid, 0, 0 }
187 };
188 
189 #undef M
190 
191 static u32 __init build_rs(u32 arg)
192 {
193 	if (arg & ~RS_MASK)
194 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
195 
196 	return (arg & RS_MASK) << RS_SH;
197 }
198 
199 static u32 __init build_rt(u32 arg)
200 {
201 	if (arg & ~RT_MASK)
202 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
203 
204 	return (arg & RT_MASK) << RT_SH;
205 }
206 
207 static u32 __init build_rd(u32 arg)
208 {
209 	if (arg & ~RD_MASK)
210 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
211 
212 	return (arg & RD_MASK) << RD_SH;
213 }
214 
215 static u32 __init build_re(u32 arg)
216 {
217 	if (arg & ~RE_MASK)
218 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
219 
220 	return (arg & RE_MASK) << RE_SH;
221 }
222 
223 static u32 __init build_simm(s32 arg)
224 {
225 	if (arg > 0x7fff || arg < -0x8000)
226 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
227 
228 	return arg & 0xffff;
229 }
230 
231 static u32 __init build_uimm(u32 arg)
232 {
233 	if (arg & ~IMM_MASK)
234 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
235 
236 	return arg & IMM_MASK;
237 }
238 
239 static u32 __init build_bimm(s32 arg)
240 {
241 	if (arg > 0x1ffff || arg < -0x20000)
242 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
243 
244 	if (arg & 0x3)
245 		printk(KERN_WARNING "Invalid TLB synthesizer branch target\n");
246 
247 	return ((arg < 0) ? (1 << 15) : 0) | ((arg >> 2) & 0x7fff);
248 }
249 
250 static u32 __init build_jimm(u32 arg)
251 {
252 	if (arg & ~((JIMM_MASK) << 2))
253 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
254 
255 	return (arg >> 2) & JIMM_MASK;
256 }
257 
258 static u32 __init build_func(u32 arg)
259 {
260 	if (arg & ~FUNC_MASK)
261 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
262 
263 	return arg & FUNC_MASK;
264 }
265 
266 static u32 __init build_set(u32 arg)
267 {
268 	if (arg & ~SET_MASK)
269 		printk(KERN_WARNING "TLB synthesizer field overflow\n");
270 
271 	return arg & SET_MASK;
272 }
273 
274 /*
275  * The order of opcode arguments is implicitly left to right,
276  * starting with RS and ending with FUNC or IMM.
277  */
278 static void __init build_insn(u32 **buf, enum opcode opc, ...)
279 {
280 	struct insn *ip = NULL;
281 	unsigned int i;
282 	va_list ap;
283 	u32 op;
284 
285 	for (i = 0; insn_table[i].opcode != insn_invalid; i++)
286 		if (insn_table[i].opcode == opc) {
287 			ip = &insn_table[i];
288 			break;
289 		}
290 
291 	if (!ip || (opc == insn_daddiu && r4k_daddiu_bug()))
292 		panic("Unsupported TLB synthesizer instruction %d", opc);
293 
294 	op = ip->match;
295 	va_start(ap, opc);
296 	if (ip->fields & RS) op |= build_rs(va_arg(ap, u32));
297 	if (ip->fields & RT) op |= build_rt(va_arg(ap, u32));
298 	if (ip->fields & RD) op |= build_rd(va_arg(ap, u32));
299 	if (ip->fields & RE) op |= build_re(va_arg(ap, u32));
300 	if (ip->fields & SIMM) op |= build_simm(va_arg(ap, s32));
301 	if (ip->fields & UIMM) op |= build_uimm(va_arg(ap, u32));
302 	if (ip->fields & BIMM) op |= build_bimm(va_arg(ap, s32));
303 	if (ip->fields & JIMM) op |= build_jimm(va_arg(ap, u32));
304 	if (ip->fields & FUNC) op |= build_func(va_arg(ap, u32));
305 	if (ip->fields & SET) op |= build_set(va_arg(ap, u32));
306 	va_end(ap);
307 
308 	**buf = op;
309 	(*buf)++;
310 }
311 
312 #define I_u1u2u3(op)						\
313 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
314 	 	unsigned int b, unsigned int c)			\
315 	{							\
316 		build_insn(buf, insn##op, a, b, c);		\
317 	}
318 
319 #define I_u2u1u3(op)						\
320 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
321 	 	unsigned int b, unsigned int c)			\
322 	{							\
323 		build_insn(buf, insn##op, b, a, c);		\
324 	}
325 
326 #define I_u3u1u2(op)						\
327 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
328 	 	unsigned int b, unsigned int c)			\
329 	{							\
330 		build_insn(buf, insn##op, b, c, a);		\
331 	}
332 
333 #define I_u1u2s3(op)						\
334 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
335 	 	unsigned int b, signed int c)			\
336 	{							\
337 		build_insn(buf, insn##op, a, b, c);		\
338 	}
339 
340 #define I_u2s3u1(op)						\
341 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
342 	 	signed int b, unsigned int c)			\
343 	{							\
344 		build_insn(buf, insn##op, c, a, b);		\
345 	}
346 
347 #define I_u2u1s3(op)						\
348 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
349 	 	unsigned int b, signed int c)			\
350 	{							\
351 		build_insn(buf, insn##op, b, a, c);		\
352 	}
353 
354 #define I_u1u2(op)						\
355 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
356 	 	unsigned int b)					\
357 	{							\
358 		build_insn(buf, insn##op, a, b);		\
359 	}
360 
361 #define I_u1s2(op)						\
362 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a, \
363 	 	signed int b)					\
364 	{							\
365 		build_insn(buf, insn##op, a, b);		\
366 	}
367 
368 #define I_u1(op)						\
369 	static void __init __maybe_unused i##op(u32 **buf, unsigned int a) \
370 	{							\
371 		build_insn(buf, insn##op, a);			\
372 	}
373 
374 #define I_0(op)							\
375 	static void __init __maybe_unused i##op(u32 **buf)	\
376 	{							\
377 		build_insn(buf, insn##op);			\
378 	}
379 
380 I_u2u1s3(_addiu);
381 I_u3u1u2(_addu);
382 I_u2u1u3(_andi);
383 I_u3u1u2(_and);
384 I_u1u2s3(_beq);
385 I_u1u2s3(_beql);
386 I_u1s2(_bgez);
387 I_u1s2(_bgezl);
388 I_u1s2(_bltz);
389 I_u1s2(_bltzl);
390 I_u1u2s3(_bne);
391 I_u1u2u3(_dmfc0);
392 I_u1u2u3(_dmtc0);
393 I_u2u1s3(_daddiu);
394 I_u3u1u2(_daddu);
395 I_u2u1u3(_dsll);
396 I_u2u1u3(_dsll32);
397 I_u2u1u3(_dsra);
398 I_u2u1u3(_dsrl);
399 I_u2u1u3(_dsrl32);
400 I_u3u1u2(_dsubu);
401 I_0(_eret);
402 I_u1(_j);
403 I_u1(_jal);
404 I_u1(_jr);
405 I_u2s3u1(_ld);
406 I_u2s3u1(_ll);
407 I_u2s3u1(_lld);
408 I_u1s2(_lui);
409 I_u2s3u1(_lw);
410 I_u1u2u3(_mfc0);
411 I_u1u2u3(_mtc0);
412 I_u2u1u3(_ori);
413 I_0(_rfe);
414 I_u2s3u1(_sc);
415 I_u2s3u1(_scd);
416 I_u2s3u1(_sd);
417 I_u2u1u3(_sll);
418 I_u2u1u3(_sra);
419 I_u2u1u3(_srl);
420 I_u3u1u2(_subu);
421 I_u2s3u1(_sw);
422 I_0(_tlbp);
423 I_0(_tlbwi);
424 I_0(_tlbwr);
425 I_u3u1u2(_xor)
426 I_u2u1u3(_xori);
427 
428 /*
429  * handling labels
430  */
431 
432 enum label_id {
433 	label_invalid,
434 	label_second_part,
435 	label_leave,
436 #ifdef MODULE_START
437 	label_module_alloc,
438 #endif
439 	label_vmalloc,
440 	label_vmalloc_done,
441 	label_tlbw_hazard,
442 	label_split,
443 	label_nopage_tlbl,
444 	label_nopage_tlbs,
445 	label_nopage_tlbm,
446 	label_smp_pgtable_change,
447 	label_r3000_write_probe_fail,
448 };
449 
450 struct label {
451 	u32 *addr;
452 	enum label_id lab;
453 };
454 
455 static void __init build_label(struct label **lab, u32 *addr,
456 			       enum label_id l)
457 {
458 	(*lab)->addr = addr;
459 	(*lab)->lab = l;
460 	(*lab)++;
461 }
462 
463 #define L_LA(lb)						\
464 	static inline void __init l##lb(struct label **lab, u32 *addr) \
465 	{							\
466 		build_label(lab, addr, label##lb);		\
467 	}
468 
469 L_LA(_second_part)
470 L_LA(_leave)
471 #ifdef MODULE_START
472 L_LA(_module_alloc)
473 #endif
474 L_LA(_vmalloc)
475 L_LA(_vmalloc_done)
476 L_LA(_tlbw_hazard)
477 L_LA(_split)
478 L_LA(_nopage_tlbl)
479 L_LA(_nopage_tlbs)
480 L_LA(_nopage_tlbm)
481 L_LA(_smp_pgtable_change)
482 L_LA(_r3000_write_probe_fail)
483 
484 /* convenience macros for instructions */
485 #ifdef CONFIG_64BIT
486 # define i_LW(buf, rs, rt, off) i_ld(buf, rs, rt, off)
487 # define i_SW(buf, rs, rt, off) i_sd(buf, rs, rt, off)
488 # define i_SLL(buf, rs, rt, sh) i_dsll(buf, rs, rt, sh)
489 # define i_SRA(buf, rs, rt, sh) i_dsra(buf, rs, rt, sh)
490 # define i_SRL(buf, rs, rt, sh) i_dsrl(buf, rs, rt, sh)
491 # define i_MFC0(buf, rt, rd...) i_dmfc0(buf, rt, rd)
492 # define i_MTC0(buf, rt, rd...) i_dmtc0(buf, rt, rd)
493 # define i_ADDIU(buf, rs, rt, val) i_daddiu(buf, rs, rt, val)
494 # define i_ADDU(buf, rs, rt, rd) i_daddu(buf, rs, rt, rd)
495 # define i_SUBU(buf, rs, rt, rd) i_dsubu(buf, rs, rt, rd)
496 # define i_LL(buf, rs, rt, off) i_lld(buf, rs, rt, off)
497 # define i_SC(buf, rs, rt, off) i_scd(buf, rs, rt, off)
498 #else
499 # define i_LW(buf, rs, rt, off) i_lw(buf, rs, rt, off)
500 # define i_SW(buf, rs, rt, off) i_sw(buf, rs, rt, off)
501 # define i_SLL(buf, rs, rt, sh) i_sll(buf, rs, rt, sh)
502 # define i_SRA(buf, rs, rt, sh) i_sra(buf, rs, rt, sh)
503 # define i_SRL(buf, rs, rt, sh) i_srl(buf, rs, rt, sh)
504 # define i_MFC0(buf, rt, rd...) i_mfc0(buf, rt, rd)
505 # define i_MTC0(buf, rt, rd...) i_mtc0(buf, rt, rd)
506 # define i_ADDIU(buf, rs, rt, val) i_addiu(buf, rs, rt, val)
507 # define i_ADDU(buf, rs, rt, rd) i_addu(buf, rs, rt, rd)
508 # define i_SUBU(buf, rs, rt, rd) i_subu(buf, rs, rt, rd)
509 # define i_LL(buf, rs, rt, off) i_ll(buf, rs, rt, off)
510 # define i_SC(buf, rs, rt, off) i_sc(buf, rs, rt, off)
511 #endif
512 
513 #define i_b(buf, off) i_beq(buf, 0, 0, off)
514 #define i_beqz(buf, rs, off) i_beq(buf, rs, 0, off)
515 #define i_beqzl(buf, rs, off) i_beql(buf, rs, 0, off)
516 #define i_bnez(buf, rs, off) i_bne(buf, rs, 0, off)
517 #define i_bnezl(buf, rs, off) i_bnel(buf, rs, 0, off)
518 #define i_move(buf, a, b) i_ADDU(buf, a, 0, b)
519 #define i_nop(buf) i_sll(buf, 0, 0, 0)
520 #define i_ssnop(buf) i_sll(buf, 0, 0, 1)
521 #define i_ehb(buf) i_sll(buf, 0, 0, 3)
522 
523 static int __init __maybe_unused in_compat_space_p(long addr)
524 {
525 	/* Is this address in 32bit compat space? */
526 #ifdef CONFIG_64BIT
527 	return (((addr) & 0xffffffff00000000L) == 0xffffffff00000000L);
528 #else
529 	return 1;
530 #endif
531 }
532 
533 static int __init __maybe_unused rel_highest(long val)
534 {
535 #ifdef CONFIG_64BIT
536 	return ((((val + 0x800080008000L) >> 48) & 0xffff) ^ 0x8000) - 0x8000;
537 #else
538 	return 0;
539 #endif
540 }
541 
542 static int __init __maybe_unused rel_higher(long val)
543 {
544 #ifdef CONFIG_64BIT
545 	return ((((val + 0x80008000L) >> 32) & 0xffff) ^ 0x8000) - 0x8000;
546 #else
547 	return 0;
548 #endif
549 }
550 
551 static int __init rel_hi(long val)
552 {
553 	return ((((val + 0x8000L) >> 16) & 0xffff) ^ 0x8000) - 0x8000;
554 }
555 
556 static int __init rel_lo(long val)
557 {
558 	return ((val & 0xffff) ^ 0x8000) - 0x8000;
559 }
560 
561 static void __init i_LA_mostly(u32 **buf, unsigned int rs, long addr)
562 {
563 	if (!in_compat_space_p(addr)) {
564 		i_lui(buf, rs, rel_highest(addr));
565 		if (rel_higher(addr))
566 			i_daddiu(buf, rs, rs, rel_higher(addr));
567 		if (rel_hi(addr)) {
568 			i_dsll(buf, rs, rs, 16);
569 			i_daddiu(buf, rs, rs, rel_hi(addr));
570 			i_dsll(buf, rs, rs, 16);
571 		} else
572 			i_dsll32(buf, rs, rs, 0);
573 	} else
574 		i_lui(buf, rs, rel_hi(addr));
575 }
576 
577 static void __init __maybe_unused i_LA(u32 **buf, unsigned int rs, long addr)
578 {
579 	i_LA_mostly(buf, rs, addr);
580 	if (rel_lo(addr)) {
581 		if (!in_compat_space_p(addr))
582 			i_daddiu(buf, rs, rs, rel_lo(addr));
583 		else
584 			i_addiu(buf, rs, rs, rel_lo(addr));
585 	}
586 }
587 
588 /*
589  * handle relocations
590  */
591 
592 struct reloc {
593 	u32 *addr;
594 	unsigned int type;
595 	enum label_id lab;
596 };
597 
598 static void __init r_mips_pc16(struct reloc **rel, u32 *addr,
599 			       enum label_id l)
600 {
601 	(*rel)->addr = addr;
602 	(*rel)->type = R_MIPS_PC16;
603 	(*rel)->lab = l;
604 	(*rel)++;
605 }
606 
607 static inline void __resolve_relocs(struct reloc *rel, struct label *lab)
608 {
609 	long laddr = (long)lab->addr;
610 	long raddr = (long)rel->addr;
611 
612 	switch (rel->type) {
613 	case R_MIPS_PC16:
614 		*rel->addr |= build_bimm(laddr - (raddr + 4));
615 		break;
616 
617 	default:
618 		panic("Unsupported TLB synthesizer relocation %d",
619 		      rel->type);
620 	}
621 }
622 
623 static void __init resolve_relocs(struct reloc *rel, struct label *lab)
624 {
625 	struct label *l;
626 
627 	for (; rel->lab != label_invalid; rel++)
628 		for (l = lab; l->lab != label_invalid; l++)
629 			if (rel->lab == l->lab)
630 				__resolve_relocs(rel, l);
631 }
632 
633 static void __init move_relocs(struct reloc *rel, u32 *first, u32 *end,
634 			       long off)
635 {
636 	for (; rel->lab != label_invalid; rel++)
637 		if (rel->addr >= first && rel->addr < end)
638 			rel->addr += off;
639 }
640 
641 static void __init move_labels(struct label *lab, u32 *first, u32 *end,
642 			       long off)
643 {
644 	for (; lab->lab != label_invalid; lab++)
645 		if (lab->addr >= first && lab->addr < end)
646 			lab->addr += off;
647 }
648 
649 static void __init copy_handler(struct reloc *rel, struct label *lab,
650 				u32 *first, u32 *end, u32 *target)
651 {
652 	long off = (long)(target - first);
653 
654 	memcpy(target, first, (end - first) * sizeof(u32));
655 
656 	move_relocs(rel, first, end, off);
657 	move_labels(lab, first, end, off);
658 }
659 
660 static int __init __maybe_unused insn_has_bdelay(struct reloc *rel,
661 						       u32 *addr)
662 {
663 	for (; rel->lab != label_invalid; rel++) {
664 		if (rel->addr == addr
665 		    && (rel->type == R_MIPS_PC16
666 			|| rel->type == R_MIPS_26))
667 			return 1;
668 	}
669 
670 	return 0;
671 }
672 
673 /* convenience functions for labeled branches */
674 static void __init __maybe_unused
675 	il_bltz(u32 **p, struct reloc **r, unsigned int reg, enum label_id l)
676 {
677 	r_mips_pc16(r, *p, l);
678 	i_bltz(p, reg, 0);
679 }
680 
681 static void __init __maybe_unused il_b(u32 **p, struct reloc **r,
682 					     enum label_id l)
683 {
684 	r_mips_pc16(r, *p, l);
685 	i_b(p, 0);
686 }
687 
688 static void __init il_beqz(u32 **p, struct reloc **r, unsigned int reg,
689 		    enum label_id l)
690 {
691 	r_mips_pc16(r, *p, l);
692 	i_beqz(p, reg, 0);
693 }
694 
695 static void __init __maybe_unused
696 il_beqzl(u32 **p, struct reloc **r, unsigned int reg, enum label_id l)
697 {
698 	r_mips_pc16(r, *p, l);
699 	i_beqzl(p, reg, 0);
700 }
701 
702 static void __init il_bnez(u32 **p, struct reloc **r, unsigned int reg,
703 		    enum label_id l)
704 {
705 	r_mips_pc16(r, *p, l);
706 	i_bnez(p, reg, 0);
707 }
708 
709 static void __init il_bgezl(u32 **p, struct reloc **r, unsigned int reg,
710 		     enum label_id l)
711 {
712 	r_mips_pc16(r, *p, l);
713 	i_bgezl(p, reg, 0);
714 }
715 
716 static void __init __maybe_unused
717 il_bgez(u32 **p, struct reloc **r, unsigned int reg, enum label_id l)
718 {
719 	r_mips_pc16(r, *p, l);
720 	i_bgez(p, reg, 0);
721 }
722 
723 /*
724  * For debug purposes.
725  */
726 static inline void dump_handler(const u32 *handler, int count)
727 {
728 	int i;
729 
730 	pr_debug("\t.set push\n");
731 	pr_debug("\t.set noreorder\n");
732 
733 	for (i = 0; i < count; i++)
734 		pr_debug("\t%p\t.word 0x%08x\n", &handler[i], handler[i]);
735 
736 	pr_debug("\t.set pop\n");
737 }
738 
739 /* The only general purpose registers allowed in TLB handlers. */
740 #define K0		26
741 #define K1		27
742 
743 /* Some CP0 registers */
744 #define C0_INDEX	0, 0
745 #define C0_ENTRYLO0	2, 0
746 #define C0_TCBIND	2, 2
747 #define C0_ENTRYLO1	3, 0
748 #define C0_CONTEXT	4, 0
749 #define C0_BADVADDR	8, 0
750 #define C0_ENTRYHI	10, 0
751 #define C0_EPC		14, 0
752 #define C0_XCONTEXT	20, 0
753 
754 #ifdef CONFIG_64BIT
755 # define GET_CONTEXT(buf, reg) i_MFC0(buf, reg, C0_XCONTEXT)
756 #else
757 # define GET_CONTEXT(buf, reg) i_MFC0(buf, reg, C0_CONTEXT)
758 #endif
759 
760 /* The worst case length of the handler is around 18 instructions for
761  * R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
762  * Maximum space available is 32 instructions for R3000 and 64
763  * instructions for R4000.
764  *
765  * We deliberately chose a buffer size of 128, so we won't scribble
766  * over anything important on overflow before we panic.
767  */
768 static u32 tlb_handler[128] __initdata;
769 
770 /* simply assume worst case size for labels and relocs */
771 static struct label labels[128] __initdata;
772 static struct reloc relocs[128] __initdata;
773 
774 /*
775  * The R3000 TLB handler is simple.
776  */
777 static void __init build_r3000_tlb_refill_handler(void)
778 {
779 	long pgdc = (long)pgd_current;
780 	u32 *p;
781 
782 	memset(tlb_handler, 0, sizeof(tlb_handler));
783 	p = tlb_handler;
784 
785 	i_mfc0(&p, K0, C0_BADVADDR);
786 	i_lui(&p, K1, rel_hi(pgdc)); /* cp0 delay */
787 	i_lw(&p, K1, rel_lo(pgdc), K1);
788 	i_srl(&p, K0, K0, 22); /* load delay */
789 	i_sll(&p, K0, K0, 2);
790 	i_addu(&p, K1, K1, K0);
791 	i_mfc0(&p, K0, C0_CONTEXT);
792 	i_lw(&p, K1, 0, K1); /* cp0 delay */
793 	i_andi(&p, K0, K0, 0xffc); /* load delay */
794 	i_addu(&p, K1, K1, K0);
795 	i_lw(&p, K0, 0, K1);
796 	i_nop(&p); /* load delay */
797 	i_mtc0(&p, K0, C0_ENTRYLO0);
798 	i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
799 	i_tlbwr(&p); /* cp0 delay */
800 	i_jr(&p, K1);
801 	i_rfe(&p); /* branch delay */
802 
803 	if (p > tlb_handler + 32)
804 		panic("TLB refill handler space exceeded");
805 
806 	pr_info("Synthesized TLB refill handler (%u instructions).\n",
807 		(unsigned int)(p - tlb_handler));
808 
809 	memcpy((void *)ebase, tlb_handler, 0x80);
810 
811 	dump_handler((u32 *)ebase, 32);
812 }
813 
814 /*
815  * The R4000 TLB handler is much more complicated. We have two
816  * consecutive handler areas with 32 instructions space each.
817  * Since they aren't used at the same time, we can overflow in the
818  * other one.To keep things simple, we first assume linear space,
819  * then we relocate it to the final handler layout as needed.
820  */
821 static u32 final_handler[64] __initdata;
822 
823 /*
824  * Hazards
825  *
826  * From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0:
827  * 2. A timing hazard exists for the TLBP instruction.
828  *
829  *      stalling_instruction
830  *      TLBP
831  *
832  * The JTLB is being read for the TLBP throughout the stall generated by the
833  * previous instruction. This is not really correct as the stalling instruction
834  * can modify the address used to access the JTLB.  The failure symptom is that
835  * the TLBP instruction will use an address created for the stalling instruction
836  * and not the address held in C0_ENHI and thus report the wrong results.
837  *
838  * The software work-around is to not allow the instruction preceding the TLBP
839  * to stall - make it an NOP or some other instruction guaranteed not to stall.
840  *
841  * Errata 2 will not be fixed.  This errata is also on the R5000.
842  *
843  * As if we MIPS hackers wouldn't know how to nop pipelines happy ...
844  */
845 static void __init __maybe_unused build_tlb_probe_entry(u32 **p)
846 {
847 	switch (current_cpu_type()) {
848 	/* Found by experiment: R4600 v2.0 needs this, too.  */
849 	case CPU_R4600:
850 	case CPU_R5000:
851 	case CPU_R5000A:
852 	case CPU_NEVADA:
853 		i_nop(p);
854 		i_tlbp(p);
855 		break;
856 
857 	default:
858 		i_tlbp(p);
859 		break;
860 	}
861 }
862 
863 /*
864  * Write random or indexed TLB entry, and care about the hazards from
865  * the preceeding mtc0 and for the following eret.
866  */
867 enum tlb_write_entry { tlb_random, tlb_indexed };
868 
869 static void __init build_tlb_write_entry(u32 **p, struct label **l,
870 					 struct reloc **r,
871 					 enum tlb_write_entry wmode)
872 {
873 	void(*tlbw)(u32 **) = NULL;
874 
875 	switch (wmode) {
876 	case tlb_random: tlbw = i_tlbwr; break;
877 	case tlb_indexed: tlbw = i_tlbwi; break;
878 	}
879 
880 	if (cpu_has_mips_r2) {
881 		i_ehb(p);
882 		tlbw(p);
883 		return;
884 	}
885 
886 	switch (current_cpu_type()) {
887 	case CPU_R4000PC:
888 	case CPU_R4000SC:
889 	case CPU_R4000MC:
890 	case CPU_R4400PC:
891 	case CPU_R4400SC:
892 	case CPU_R4400MC:
893 		/*
894 		 * This branch uses up a mtc0 hazard nop slot and saves
895 		 * two nops after the tlbw instruction.
896 		 */
897 		il_bgezl(p, r, 0, label_tlbw_hazard);
898 		tlbw(p);
899 		l_tlbw_hazard(l, *p);
900 		i_nop(p);
901 		break;
902 
903 	case CPU_R4600:
904 	case CPU_R4700:
905 	case CPU_R5000:
906 	case CPU_R5000A:
907 		i_nop(p);
908 		tlbw(p);
909 		i_nop(p);
910 		break;
911 
912 	case CPU_R4300:
913 	case CPU_5KC:
914 	case CPU_TX49XX:
915 	case CPU_AU1000:
916 	case CPU_AU1100:
917 	case CPU_AU1500:
918 	case CPU_AU1550:
919 	case CPU_AU1200:
920 	case CPU_AU1210:
921 	case CPU_AU1250:
922 	case CPU_PR4450:
923 		i_nop(p);
924 		tlbw(p);
925 		break;
926 
927 	case CPU_R10000:
928 	case CPU_R12000:
929 	case CPU_R14000:
930 	case CPU_4KC:
931 	case CPU_SB1:
932 	case CPU_SB1A:
933 	case CPU_4KSC:
934 	case CPU_20KC:
935 	case CPU_25KF:
936 	case CPU_BCM3302:
937 	case CPU_BCM4710:
938 	case CPU_LOONGSON2:
939 		if (m4kc_tlbp_war())
940 			i_nop(p);
941 		tlbw(p);
942 		break;
943 
944 	case CPU_NEVADA:
945 		i_nop(p); /* QED specifies 2 nops hazard */
946 		/*
947 		 * This branch uses up a mtc0 hazard nop slot and saves
948 		 * a nop after the tlbw instruction.
949 		 */
950 		il_bgezl(p, r, 0, label_tlbw_hazard);
951 		tlbw(p);
952 		l_tlbw_hazard(l, *p);
953 		break;
954 
955 	case CPU_RM7000:
956 		i_nop(p);
957 		i_nop(p);
958 		i_nop(p);
959 		i_nop(p);
960 		tlbw(p);
961 		break;
962 
963 	case CPU_RM9000:
964 		/*
965 		 * When the JTLB is updated by tlbwi or tlbwr, a subsequent
966 		 * use of the JTLB for instructions should not occur for 4
967 		 * cpu cycles and use for data translations should not occur
968 		 * for 3 cpu cycles.
969 		 */
970 		i_ssnop(p);
971 		i_ssnop(p);
972 		i_ssnop(p);
973 		i_ssnop(p);
974 		tlbw(p);
975 		i_ssnop(p);
976 		i_ssnop(p);
977 		i_ssnop(p);
978 		i_ssnop(p);
979 		break;
980 
981 	case CPU_VR4111:
982 	case CPU_VR4121:
983 	case CPU_VR4122:
984 	case CPU_VR4181:
985 	case CPU_VR4181A:
986 		i_nop(p);
987 		i_nop(p);
988 		tlbw(p);
989 		i_nop(p);
990 		i_nop(p);
991 		break;
992 
993 	case CPU_VR4131:
994 	case CPU_VR4133:
995 	case CPU_R5432:
996 		i_nop(p);
997 		i_nop(p);
998 		tlbw(p);
999 		break;
1000 
1001 	default:
1002 		panic("No TLB refill handler yet (CPU type: %d)",
1003 		      current_cpu_data.cputype);
1004 		break;
1005 	}
1006 }
1007 
1008 #ifdef CONFIG_64BIT
1009 /*
1010  * TMP and PTR are scratch.
1011  * TMP will be clobbered, PTR will hold the pmd entry.
1012  */
1013 static void __init
1014 build_get_pmde64(u32 **p, struct label **l, struct reloc **r,
1015 		 unsigned int tmp, unsigned int ptr)
1016 {
1017 	long pgdc = (long)pgd_current;
1018 
1019 	/*
1020 	 * The vmalloc handling is not in the hotpath.
1021 	 */
1022 	i_dmfc0(p, tmp, C0_BADVADDR);
1023 #ifdef MODULE_START
1024 	il_bltz(p, r, tmp, label_module_alloc);
1025 #else
1026 	il_bltz(p, r, tmp, label_vmalloc);
1027 #endif
1028 	/* No i_nop needed here, since the next insn doesn't touch TMP. */
1029 
1030 #ifdef CONFIG_SMP
1031 # ifdef  CONFIG_MIPS_MT_SMTC
1032 	/*
1033 	 * SMTC uses TCBind value as "CPU" index
1034 	 */
1035 	i_mfc0(p, ptr, C0_TCBIND);
1036 	i_dsrl(p, ptr, ptr, 19);
1037 # else
1038 	/*
1039 	 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
1040 	 * stored in CONTEXT.
1041 	 */
1042 	i_dmfc0(p, ptr, C0_CONTEXT);
1043 	i_dsrl(p, ptr, ptr, 23);
1044 #endif
1045 	i_LA_mostly(p, tmp, pgdc);
1046 	i_daddu(p, ptr, ptr, tmp);
1047 	i_dmfc0(p, tmp, C0_BADVADDR);
1048 	i_ld(p, ptr, rel_lo(pgdc), ptr);
1049 #else
1050 	i_LA_mostly(p, ptr, pgdc);
1051 	i_ld(p, ptr, rel_lo(pgdc), ptr);
1052 #endif
1053 
1054 	l_vmalloc_done(l, *p);
1055 
1056 	if (PGDIR_SHIFT - 3 < 32)		/* get pgd offset in bytes */
1057 		i_dsrl(p, tmp, tmp, PGDIR_SHIFT-3);
1058 	else
1059 		i_dsrl32(p, tmp, tmp, PGDIR_SHIFT - 3 - 32);
1060 
1061 	i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
1062 	i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
1063 	i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
1064 	i_ld(p, ptr, 0, ptr); /* get pmd pointer */
1065 	i_dsrl(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
1066 	i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
1067 	i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
1068 }
1069 
1070 /*
1071  * BVADDR is the faulting address, PTR is scratch.
1072  * PTR will hold the pgd for vmalloc.
1073  */
1074 static void __init
1075 build_get_pgd_vmalloc64(u32 **p, struct label **l, struct reloc **r,
1076 			unsigned int bvaddr, unsigned int ptr)
1077 {
1078 	long swpd = (long)swapper_pg_dir;
1079 
1080 #ifdef MODULE_START
1081 	long modd = (long)module_pg_dir;
1082 
1083 	l_module_alloc(l, *p);
1084 	/*
1085 	 * Assumption:
1086 	 * VMALLOC_START >= 0xc000000000000000UL
1087 	 * MODULE_START >= 0xe000000000000000UL
1088 	 */
1089 	i_SLL(p, ptr, bvaddr, 2);
1090 	il_bgez(p, r, ptr, label_vmalloc);
1091 
1092 	if (in_compat_space_p(MODULE_START) && !rel_lo(MODULE_START)) {
1093 		i_lui(p, ptr, rel_hi(MODULE_START)); /* delay slot */
1094 	} else {
1095 		/* unlikely configuration */
1096 		i_nop(p); /* delay slot */
1097 		i_LA(p, ptr, MODULE_START);
1098 	}
1099 	i_dsubu(p, bvaddr, bvaddr, ptr);
1100 
1101 	if (in_compat_space_p(modd) && !rel_lo(modd)) {
1102 		il_b(p, r, label_vmalloc_done);
1103 		i_lui(p, ptr, rel_hi(modd));
1104 	} else {
1105 		i_LA_mostly(p, ptr, modd);
1106 		il_b(p, r, label_vmalloc_done);
1107 		if (in_compat_space_p(modd))
1108 			i_addiu(p, ptr, ptr, rel_lo(modd));
1109 		else
1110 			i_daddiu(p, ptr, ptr, rel_lo(modd));
1111 	}
1112 
1113 	l_vmalloc(l, *p);
1114 	if (in_compat_space_p(MODULE_START) && !rel_lo(MODULE_START) &&
1115 	    MODULE_START << 32 == VMALLOC_START)
1116 		i_dsll32(p, ptr, ptr, 0);	/* typical case */
1117 	else
1118 		i_LA(p, ptr, VMALLOC_START);
1119 #else
1120 	l_vmalloc(l, *p);
1121 	i_LA(p, ptr, VMALLOC_START);
1122 #endif
1123 	i_dsubu(p, bvaddr, bvaddr, ptr);
1124 
1125 	if (in_compat_space_p(swpd) && !rel_lo(swpd)) {
1126 		il_b(p, r, label_vmalloc_done);
1127 		i_lui(p, ptr, rel_hi(swpd));
1128 	} else {
1129 		i_LA_mostly(p, ptr, swpd);
1130 		il_b(p, r, label_vmalloc_done);
1131 		if (in_compat_space_p(swpd))
1132 			i_addiu(p, ptr, ptr, rel_lo(swpd));
1133 		else
1134 			i_daddiu(p, ptr, ptr, rel_lo(swpd));
1135 	}
1136 }
1137 
1138 #else /* !CONFIG_64BIT */
1139 
1140 /*
1141  * TMP and PTR are scratch.
1142  * TMP will be clobbered, PTR will hold the pgd entry.
1143  */
1144 static void __init __maybe_unused
1145 build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
1146 {
1147 	long pgdc = (long)pgd_current;
1148 
1149 	/* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
1150 #ifdef CONFIG_SMP
1151 #ifdef  CONFIG_MIPS_MT_SMTC
1152 	/*
1153 	 * SMTC uses TCBind value as "CPU" index
1154 	 */
1155 	i_mfc0(p, ptr, C0_TCBIND);
1156 	i_LA_mostly(p, tmp, pgdc);
1157 	i_srl(p, ptr, ptr, 19);
1158 #else
1159 	/*
1160 	 * smp_processor_id() << 3 is stored in CONTEXT.
1161          */
1162 	i_mfc0(p, ptr, C0_CONTEXT);
1163 	i_LA_mostly(p, tmp, pgdc);
1164 	i_srl(p, ptr, ptr, 23);
1165 #endif
1166 	i_addu(p, ptr, tmp, ptr);
1167 #else
1168 	i_LA_mostly(p, ptr, pgdc);
1169 #endif
1170 	i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
1171 	i_lw(p, ptr, rel_lo(pgdc), ptr);
1172 	i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
1173 	i_sll(p, tmp, tmp, PGD_T_LOG2);
1174 	i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
1175 }
1176 
1177 #endif /* !CONFIG_64BIT */
1178 
1179 static void __init build_adjust_context(u32 **p, unsigned int ctx)
1180 {
1181 	unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
1182 	unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
1183 
1184 	switch (current_cpu_type()) {
1185 	case CPU_VR41XX:
1186 	case CPU_VR4111:
1187 	case CPU_VR4121:
1188 	case CPU_VR4122:
1189 	case CPU_VR4131:
1190 	case CPU_VR4181:
1191 	case CPU_VR4181A:
1192 	case CPU_VR4133:
1193 		shift += 2;
1194 		break;
1195 
1196 	default:
1197 		break;
1198 	}
1199 
1200 	if (shift)
1201 		i_SRL(p, ctx, ctx, shift);
1202 	i_andi(p, ctx, ctx, mask);
1203 }
1204 
1205 static void __init build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
1206 {
1207 	/*
1208 	 * Bug workaround for the Nevada. It seems as if under certain
1209 	 * circumstances the move from cp0_context might produce a
1210 	 * bogus result when the mfc0 instruction and its consumer are
1211 	 * in a different cacheline or a load instruction, probably any
1212 	 * memory reference, is between them.
1213 	 */
1214 	switch (current_cpu_type()) {
1215 	case CPU_NEVADA:
1216 		i_LW(p, ptr, 0, ptr);
1217 		GET_CONTEXT(p, tmp); /* get context reg */
1218 		break;
1219 
1220 	default:
1221 		GET_CONTEXT(p, tmp); /* get context reg */
1222 		i_LW(p, ptr, 0, ptr);
1223 		break;
1224 	}
1225 
1226 	build_adjust_context(p, tmp);
1227 	i_ADDU(p, ptr, ptr, tmp); /* add in offset */
1228 }
1229 
1230 static void __init build_update_entries(u32 **p, unsigned int tmp,
1231 					unsigned int ptep)
1232 {
1233 	/*
1234 	 * 64bit address support (36bit on a 32bit CPU) in a 32bit
1235 	 * Kernel is a special case. Only a few CPUs use it.
1236 	 */
1237 #ifdef CONFIG_64BIT_PHYS_ADDR
1238 	if (cpu_has_64bits) {
1239 		i_ld(p, tmp, 0, ptep); /* get even pte */
1240 		i_ld(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
1241 		i_dsrl(p, tmp, tmp, 6); /* convert to entrylo0 */
1242 		i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
1243 		i_dsrl(p, ptep, ptep, 6); /* convert to entrylo1 */
1244 		i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
1245 	} else {
1246 		int pte_off_even = sizeof(pte_t) / 2;
1247 		int pte_off_odd = pte_off_even + sizeof(pte_t);
1248 
1249 		/* The pte entries are pre-shifted */
1250 		i_lw(p, tmp, pte_off_even, ptep); /* get even pte */
1251 		i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
1252 		i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */
1253 		i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
1254 	}
1255 #else
1256 	i_LW(p, tmp, 0, ptep); /* get even pte */
1257 	i_LW(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
1258 	if (r45k_bvahwbug())
1259 		build_tlb_probe_entry(p);
1260 	i_SRL(p, tmp, tmp, 6); /* convert to entrylo0 */
1261 	if (r4k_250MHZhwbug())
1262 		i_mtc0(p, 0, C0_ENTRYLO0);
1263 	i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
1264 	i_SRL(p, ptep, ptep, 6); /* convert to entrylo1 */
1265 	if (r45k_bvahwbug())
1266 		i_mfc0(p, tmp, C0_INDEX);
1267 	if (r4k_250MHZhwbug())
1268 		i_mtc0(p, 0, C0_ENTRYLO1);
1269 	i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
1270 #endif
1271 }
1272 
1273 static void __init build_r4000_tlb_refill_handler(void)
1274 {
1275 	u32 *p = tlb_handler;
1276 	struct label *l = labels;
1277 	struct reloc *r = relocs;
1278 	u32 *f;
1279 	unsigned int final_len;
1280 
1281 	memset(tlb_handler, 0, sizeof(tlb_handler));
1282 	memset(labels, 0, sizeof(labels));
1283 	memset(relocs, 0, sizeof(relocs));
1284 	memset(final_handler, 0, sizeof(final_handler));
1285 
1286 	/*
1287 	 * create the plain linear handler
1288 	 */
1289 	if (bcm1250_m3_war()) {
1290 		i_MFC0(&p, K0, C0_BADVADDR);
1291 		i_MFC0(&p, K1, C0_ENTRYHI);
1292 		i_xor(&p, K0, K0, K1);
1293 		i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
1294 		il_bnez(&p, &r, K0, label_leave);
1295 		/* No need for i_nop */
1296 	}
1297 
1298 #ifdef CONFIG_64BIT
1299 	build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
1300 #else
1301 	build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
1302 #endif
1303 
1304 	build_get_ptep(&p, K0, K1);
1305 	build_update_entries(&p, K0, K1);
1306 	build_tlb_write_entry(&p, &l, &r, tlb_random);
1307 	l_leave(&l, p);
1308 	i_eret(&p); /* return from trap */
1309 
1310 #ifdef CONFIG_64BIT
1311 	build_get_pgd_vmalloc64(&p, &l, &r, K0, K1);
1312 #endif
1313 
1314 	/*
1315 	 * Overflow check: For the 64bit handler, we need at least one
1316 	 * free instruction slot for the wrap-around branch. In worst
1317 	 * case, if the intended insertion point is a delay slot, we
1318 	 * need three, with the second nop'ed and the third being
1319 	 * unused.
1320 	 */
1321 	/* Loongson2 ebase is different than r4k, we have more space */
1322 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
1323 	if ((p - tlb_handler) > 64)
1324 		panic("TLB refill handler space exceeded");
1325 #else
1326 	if (((p - tlb_handler) > 63)
1327 	    || (((p - tlb_handler) > 61)
1328 		&& insn_has_bdelay(relocs, tlb_handler + 29)))
1329 		panic("TLB refill handler space exceeded");
1330 #endif
1331 
1332 	/*
1333 	 * Now fold the handler in the TLB refill handler space.
1334 	 */
1335 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
1336 	f = final_handler;
1337 	/* Simplest case, just copy the handler. */
1338 	copy_handler(relocs, labels, tlb_handler, p, f);
1339 	final_len = p - tlb_handler;
1340 #else /* CONFIG_64BIT */
1341 	f = final_handler + 32;
1342 	if ((p - tlb_handler) <= 32) {
1343 		/* Just copy the handler. */
1344 		copy_handler(relocs, labels, tlb_handler, p, f);
1345 		final_len = p - tlb_handler;
1346 	} else {
1347 		u32 *split = tlb_handler + 30;
1348 
1349 		/*
1350 		 * Find the split point.
1351 		 */
1352 		if (insn_has_bdelay(relocs, split - 1))
1353 			split--;
1354 
1355 		/* Copy first part of the handler. */
1356 		copy_handler(relocs, labels, tlb_handler, split, f);
1357 		f += split - tlb_handler;
1358 
1359 		/* Insert branch. */
1360 		l_split(&l, final_handler);
1361 		il_b(&f, &r, label_split);
1362 		if (insn_has_bdelay(relocs, split))
1363 			i_nop(&f);
1364 		else {
1365 			copy_handler(relocs, labels, split, split + 1, f);
1366 			move_labels(labels, f, f + 1, -1);
1367 			f++;
1368 			split++;
1369 		}
1370 
1371 		/* Copy the rest of the handler. */
1372 		copy_handler(relocs, labels, split, p, final_handler);
1373 		final_len = (f - (final_handler + 32)) + (p - split);
1374 	}
1375 #endif /* CONFIG_64BIT */
1376 
1377 	resolve_relocs(relocs, labels);
1378 	pr_info("Synthesized TLB refill handler (%u instructions).\n",
1379 		final_len);
1380 
1381 	memcpy((void *)ebase, final_handler, 0x100);
1382 
1383 	dump_handler((u32 *)ebase, 64);
1384 }
1385 
1386 /*
1387  * TLB load/store/modify handlers.
1388  *
1389  * Only the fastpath gets synthesized at runtime, the slowpath for
1390  * do_page_fault remains normal asm.
1391  */
1392 extern void tlb_do_page_fault_0(void);
1393 extern void tlb_do_page_fault_1(void);
1394 
1395 /*
1396  * 128 instructions for the fastpath handler is generous and should
1397  * never be exceeded.
1398  */
1399 #define FASTPATH_SIZE 128
1400 
1401 u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned;
1402 u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned;
1403 u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned;
1404 
1405 static void __init
1406 iPTE_LW(u32 **p, struct label **l, unsigned int pte, unsigned int ptr)
1407 {
1408 #ifdef CONFIG_SMP
1409 # ifdef CONFIG_64BIT_PHYS_ADDR
1410 	if (cpu_has_64bits)
1411 		i_lld(p, pte, 0, ptr);
1412 	else
1413 # endif
1414 		i_LL(p, pte, 0, ptr);
1415 #else
1416 # ifdef CONFIG_64BIT_PHYS_ADDR
1417 	if (cpu_has_64bits)
1418 		i_ld(p, pte, 0, ptr);
1419 	else
1420 # endif
1421 		i_LW(p, pte, 0, ptr);
1422 #endif
1423 }
1424 
1425 static void __init
1426 iPTE_SW(u32 **p, struct reloc **r, unsigned int pte, unsigned int ptr,
1427 	unsigned int mode)
1428 {
1429 #ifdef CONFIG_64BIT_PHYS_ADDR
1430 	unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
1431 #endif
1432 
1433 	i_ori(p, pte, pte, mode);
1434 #ifdef CONFIG_SMP
1435 # ifdef CONFIG_64BIT_PHYS_ADDR
1436 	if (cpu_has_64bits)
1437 		i_scd(p, pte, 0, ptr);
1438 	else
1439 # endif
1440 		i_SC(p, pte, 0, ptr);
1441 
1442 	if (r10000_llsc_war())
1443 		il_beqzl(p, r, pte, label_smp_pgtable_change);
1444 	else
1445 		il_beqz(p, r, pte, label_smp_pgtable_change);
1446 
1447 # ifdef CONFIG_64BIT_PHYS_ADDR
1448 	if (!cpu_has_64bits) {
1449 		/* no i_nop needed */
1450 		i_ll(p, pte, sizeof(pte_t) / 2, ptr);
1451 		i_ori(p, pte, pte, hwmode);
1452 		i_sc(p, pte, sizeof(pte_t) / 2, ptr);
1453 		il_beqz(p, r, pte, label_smp_pgtable_change);
1454 		/* no i_nop needed */
1455 		i_lw(p, pte, 0, ptr);
1456 	} else
1457 		i_nop(p);
1458 # else
1459 	i_nop(p);
1460 # endif
1461 #else
1462 # ifdef CONFIG_64BIT_PHYS_ADDR
1463 	if (cpu_has_64bits)
1464 		i_sd(p, pte, 0, ptr);
1465 	else
1466 # endif
1467 		i_SW(p, pte, 0, ptr);
1468 
1469 # ifdef CONFIG_64BIT_PHYS_ADDR
1470 	if (!cpu_has_64bits) {
1471 		i_lw(p, pte, sizeof(pte_t) / 2, ptr);
1472 		i_ori(p, pte, pte, hwmode);
1473 		i_sw(p, pte, sizeof(pte_t) / 2, ptr);
1474 		i_lw(p, pte, 0, ptr);
1475 	}
1476 # endif
1477 #endif
1478 }
1479 
1480 /*
1481  * Check if PTE is present, if not then jump to LABEL. PTR points to
1482  * the page table where this PTE is located, PTE will be re-loaded
1483  * with it's original value.
1484  */
1485 static void __init
1486 build_pte_present(u32 **p, struct label **l, struct reloc **r,
1487 		  unsigned int pte, unsigned int ptr, enum label_id lid)
1488 {
1489 	i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
1490 	i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
1491 	il_bnez(p, r, pte, lid);
1492 	iPTE_LW(p, l, pte, ptr);
1493 }
1494 
1495 /* Make PTE valid, store result in PTR. */
1496 static void __init
1497 build_make_valid(u32 **p, struct reloc **r, unsigned int pte,
1498 		 unsigned int ptr)
1499 {
1500 	unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
1501 
1502 	iPTE_SW(p, r, pte, ptr, mode);
1503 }
1504 
1505 /*
1506  * Check if PTE can be written to, if not branch to LABEL. Regardless
1507  * restore PTE with value from PTR when done.
1508  */
1509 static void __init
1510 build_pte_writable(u32 **p, struct label **l, struct reloc **r,
1511 		   unsigned int pte, unsigned int ptr, enum label_id lid)
1512 {
1513 	i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1514 	i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1515 	il_bnez(p, r, pte, lid);
1516 	iPTE_LW(p, l, pte, ptr);
1517 }
1518 
1519 /* Make PTE writable, update software status bits as well, then store
1520  * at PTR.
1521  */
1522 static void __init
1523 build_make_write(u32 **p, struct reloc **r, unsigned int pte,
1524 		 unsigned int ptr)
1525 {
1526 	unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1527 			     | _PAGE_DIRTY);
1528 
1529 	iPTE_SW(p, r, pte, ptr, mode);
1530 }
1531 
1532 /*
1533  * Check if PTE can be modified, if not branch to LABEL. Regardless
1534  * restore PTE with value from PTR when done.
1535  */
1536 static void __init
1537 build_pte_modifiable(u32 **p, struct label **l, struct reloc **r,
1538 		     unsigned int pte, unsigned int ptr, enum label_id lid)
1539 {
1540 	i_andi(p, pte, pte, _PAGE_WRITE);
1541 	il_beqz(p, r, pte, lid);
1542 	iPTE_LW(p, l, pte, ptr);
1543 }
1544 
1545 /*
1546  * R3000 style TLB load/store/modify handlers.
1547  */
1548 
1549 /*
1550  * This places the pte into ENTRYLO0 and writes it with tlbwi.
1551  * Then it returns.
1552  */
1553 static void __init
1554 build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1555 {
1556 	i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1557 	i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1558 	i_tlbwi(p);
1559 	i_jr(p, tmp);
1560 	i_rfe(p); /* branch delay */
1561 }
1562 
1563 /*
1564  * This places the pte into ENTRYLO0 and writes it with tlbwi
1565  * or tlbwr as appropriate.  This is because the index register
1566  * may have the probe fail bit set as a result of a trap on a
1567  * kseg2 access, i.e. without refill.  Then it returns.
1568  */
1569 static void __init
1570 build_r3000_tlb_reload_write(u32 **p, struct label **l, struct reloc **r,
1571 			     unsigned int pte, unsigned int tmp)
1572 {
1573 	i_mfc0(p, tmp, C0_INDEX);
1574 	i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1575 	il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1576 	i_mfc0(p, tmp, C0_EPC); /* branch delay */
1577 	i_tlbwi(p); /* cp0 delay */
1578 	i_jr(p, tmp);
1579 	i_rfe(p); /* branch delay */
1580 	l_r3000_write_probe_fail(l, *p);
1581 	i_tlbwr(p); /* cp0 delay */
1582 	i_jr(p, tmp);
1583 	i_rfe(p); /* branch delay */
1584 }
1585 
1586 static void __init
1587 build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1588 				   unsigned int ptr)
1589 {
1590 	long pgdc = (long)pgd_current;
1591 
1592 	i_mfc0(p, pte, C0_BADVADDR);
1593 	i_lui(p, ptr, rel_hi(pgdc)); /* cp0 delay */
1594 	i_lw(p, ptr, rel_lo(pgdc), ptr);
1595 	i_srl(p, pte, pte, 22); /* load delay */
1596 	i_sll(p, pte, pte, 2);
1597 	i_addu(p, ptr, ptr, pte);
1598 	i_mfc0(p, pte, C0_CONTEXT);
1599 	i_lw(p, ptr, 0, ptr); /* cp0 delay */
1600 	i_andi(p, pte, pte, 0xffc); /* load delay */
1601 	i_addu(p, ptr, ptr, pte);
1602 	i_lw(p, pte, 0, ptr);
1603 	i_tlbp(p); /* load delay */
1604 }
1605 
1606 static void __init build_r3000_tlb_load_handler(void)
1607 {
1608 	u32 *p = handle_tlbl;
1609 	struct label *l = labels;
1610 	struct reloc *r = relocs;
1611 
1612 	memset(handle_tlbl, 0, sizeof(handle_tlbl));
1613 	memset(labels, 0, sizeof(labels));
1614 	memset(relocs, 0, sizeof(relocs));
1615 
1616 	build_r3000_tlbchange_handler_head(&p, K0, K1);
1617 	build_pte_present(&p, &l, &r, K0, K1, label_nopage_tlbl);
1618 	i_nop(&p); /* load delay */
1619 	build_make_valid(&p, &r, K0, K1);
1620 	build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1621 
1622 	l_nopage_tlbl(&l, p);
1623 	i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1624 	i_nop(&p);
1625 
1626 	if ((p - handle_tlbl) > FASTPATH_SIZE)
1627 		panic("TLB load handler fastpath space exceeded");
1628 
1629 	resolve_relocs(relocs, labels);
1630 	pr_info("Synthesized TLB load handler fastpath (%u instructions).\n",
1631 		(unsigned int)(p - handle_tlbl));
1632 
1633 	dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1634 }
1635 
1636 static void __init build_r3000_tlb_store_handler(void)
1637 {
1638 	u32 *p = handle_tlbs;
1639 	struct label *l = labels;
1640 	struct reloc *r = relocs;
1641 
1642 	memset(handle_tlbs, 0, sizeof(handle_tlbs));
1643 	memset(labels, 0, sizeof(labels));
1644 	memset(relocs, 0, sizeof(relocs));
1645 
1646 	build_r3000_tlbchange_handler_head(&p, K0, K1);
1647 	build_pte_writable(&p, &l, &r, K0, K1, label_nopage_tlbs);
1648 	i_nop(&p); /* load delay */
1649 	build_make_write(&p, &r, K0, K1);
1650 	build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1651 
1652 	l_nopage_tlbs(&l, p);
1653 	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1654 	i_nop(&p);
1655 
1656 	if ((p - handle_tlbs) > FASTPATH_SIZE)
1657 		panic("TLB store handler fastpath space exceeded");
1658 
1659 	resolve_relocs(relocs, labels);
1660 	pr_info("Synthesized TLB store handler fastpath (%u instructions).\n",
1661 		(unsigned int)(p - handle_tlbs));
1662 
1663 	dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
1664 }
1665 
1666 static void __init build_r3000_tlb_modify_handler(void)
1667 {
1668 	u32 *p = handle_tlbm;
1669 	struct label *l = labels;
1670 	struct reloc *r = relocs;
1671 
1672 	memset(handle_tlbm, 0, sizeof(handle_tlbm));
1673 	memset(labels, 0, sizeof(labels));
1674 	memset(relocs, 0, sizeof(relocs));
1675 
1676 	build_r3000_tlbchange_handler_head(&p, K0, K1);
1677 	build_pte_modifiable(&p, &l, &r, K0, K1, label_nopage_tlbm);
1678 	i_nop(&p); /* load delay */
1679 	build_make_write(&p, &r, K0, K1);
1680 	build_r3000_pte_reload_tlbwi(&p, K0, K1);
1681 
1682 	l_nopage_tlbm(&l, p);
1683 	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1684 	i_nop(&p);
1685 
1686 	if ((p - handle_tlbm) > FASTPATH_SIZE)
1687 		panic("TLB modify handler fastpath space exceeded");
1688 
1689 	resolve_relocs(relocs, labels);
1690 	pr_info("Synthesized TLB modify handler fastpath (%u instructions).\n",
1691 		(unsigned int)(p - handle_tlbm));
1692 
1693 	dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
1694 }
1695 
1696 /*
1697  * R4000 style TLB load/store/modify handlers.
1698  */
1699 static void __init
1700 build_r4000_tlbchange_handler_head(u32 **p, struct label **l,
1701 				   struct reloc **r, unsigned int pte,
1702 				   unsigned int ptr)
1703 {
1704 #ifdef CONFIG_64BIT
1705 	build_get_pmde64(p, l, r, pte, ptr); /* get pmd in ptr */
1706 #else
1707 	build_get_pgde32(p, pte, ptr); /* get pgd in ptr */
1708 #endif
1709 
1710 	i_MFC0(p, pte, C0_BADVADDR);
1711 	i_LW(p, ptr, 0, ptr);
1712 	i_SRL(p, pte, pte, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
1713 	i_andi(p, pte, pte, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
1714 	i_ADDU(p, ptr, ptr, pte);
1715 
1716 #ifdef CONFIG_SMP
1717 	l_smp_pgtable_change(l, *p);
1718 # endif
1719 	iPTE_LW(p, l, pte, ptr); /* get even pte */
1720 	if (!m4kc_tlbp_war())
1721 		build_tlb_probe_entry(p);
1722 }
1723 
1724 static void __init
1725 build_r4000_tlbchange_handler_tail(u32 **p, struct label **l,
1726 				   struct reloc **r, unsigned int tmp,
1727 				   unsigned int ptr)
1728 {
1729 	i_ori(p, ptr, ptr, sizeof(pte_t));
1730 	i_xori(p, ptr, ptr, sizeof(pte_t));
1731 	build_update_entries(p, tmp, ptr);
1732 	build_tlb_write_entry(p, l, r, tlb_indexed);
1733 	l_leave(l, *p);
1734 	i_eret(p); /* return from trap */
1735 
1736 #ifdef CONFIG_64BIT
1737 	build_get_pgd_vmalloc64(p, l, r, tmp, ptr);
1738 #endif
1739 }
1740 
1741 static void __init build_r4000_tlb_load_handler(void)
1742 {
1743 	u32 *p = handle_tlbl;
1744 	struct label *l = labels;
1745 	struct reloc *r = relocs;
1746 
1747 	memset(handle_tlbl, 0, sizeof(handle_tlbl));
1748 	memset(labels, 0, sizeof(labels));
1749 	memset(relocs, 0, sizeof(relocs));
1750 
1751 	if (bcm1250_m3_war()) {
1752 		i_MFC0(&p, K0, C0_BADVADDR);
1753 		i_MFC0(&p, K1, C0_ENTRYHI);
1754 		i_xor(&p, K0, K0, K1);
1755 		i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
1756 		il_bnez(&p, &r, K0, label_leave);
1757 		/* No need for i_nop */
1758 	}
1759 
1760 	build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1761 	build_pte_present(&p, &l, &r, K0, K1, label_nopage_tlbl);
1762 	if (m4kc_tlbp_war())
1763 		build_tlb_probe_entry(&p);
1764 	build_make_valid(&p, &r, K0, K1);
1765 	build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1766 
1767 	l_nopage_tlbl(&l, p);
1768 	i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1769 	i_nop(&p);
1770 
1771 	if ((p - handle_tlbl) > FASTPATH_SIZE)
1772 		panic("TLB load handler fastpath space exceeded");
1773 
1774 	resolve_relocs(relocs, labels);
1775 	pr_info("Synthesized TLB load handler fastpath (%u instructions).\n",
1776 		(unsigned int)(p - handle_tlbl));
1777 
1778 	dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1779 }
1780 
1781 static void __init build_r4000_tlb_store_handler(void)
1782 {
1783 	u32 *p = handle_tlbs;
1784 	struct label *l = labels;
1785 	struct reloc *r = relocs;
1786 
1787 	memset(handle_tlbs, 0, sizeof(handle_tlbs));
1788 	memset(labels, 0, sizeof(labels));
1789 	memset(relocs, 0, sizeof(relocs));
1790 
1791 	build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1792 	build_pte_writable(&p, &l, &r, K0, K1, label_nopage_tlbs);
1793 	if (m4kc_tlbp_war())
1794 		build_tlb_probe_entry(&p);
1795 	build_make_write(&p, &r, K0, K1);
1796 	build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1797 
1798 	l_nopage_tlbs(&l, p);
1799 	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1800 	i_nop(&p);
1801 
1802 	if ((p - handle_tlbs) > FASTPATH_SIZE)
1803 		panic("TLB store handler fastpath space exceeded");
1804 
1805 	resolve_relocs(relocs, labels);
1806 	pr_info("Synthesized TLB store handler fastpath (%u instructions).\n",
1807 		(unsigned int)(p - handle_tlbs));
1808 
1809 	dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
1810 }
1811 
1812 static void __init build_r4000_tlb_modify_handler(void)
1813 {
1814 	u32 *p = handle_tlbm;
1815 	struct label *l = labels;
1816 	struct reloc *r = relocs;
1817 
1818 	memset(handle_tlbm, 0, sizeof(handle_tlbm));
1819 	memset(labels, 0, sizeof(labels));
1820 	memset(relocs, 0, sizeof(relocs));
1821 
1822 	build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1823 	build_pte_modifiable(&p, &l, &r, K0, K1, label_nopage_tlbm);
1824 	if (m4kc_tlbp_war())
1825 		build_tlb_probe_entry(&p);
1826 	/* Present and writable bits set, set accessed and dirty bits. */
1827 	build_make_write(&p, &r, K0, K1);
1828 	build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1829 
1830 	l_nopage_tlbm(&l, p);
1831 	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1832 	i_nop(&p);
1833 
1834 	if ((p - handle_tlbm) > FASTPATH_SIZE)
1835 		panic("TLB modify handler fastpath space exceeded");
1836 
1837 	resolve_relocs(relocs, labels);
1838 	pr_info("Synthesized TLB modify handler fastpath (%u instructions).\n",
1839 		(unsigned int)(p - handle_tlbm));
1840 
1841 	dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
1842 }
1843 
1844 void __init build_tlb_refill_handler(void)
1845 {
1846 	/*
1847 	 * The refill handler is generated per-CPU, multi-node systems
1848 	 * may have local storage for it. The other handlers are only
1849 	 * needed once.
1850 	 */
1851 	static int run_once = 0;
1852 
1853 	switch (current_cpu_type()) {
1854 	case CPU_R2000:
1855 	case CPU_R3000:
1856 	case CPU_R3000A:
1857 	case CPU_R3081E:
1858 	case CPU_TX3912:
1859 	case CPU_TX3922:
1860 	case CPU_TX3927:
1861 		build_r3000_tlb_refill_handler();
1862 		if (!run_once) {
1863 			build_r3000_tlb_load_handler();
1864 			build_r3000_tlb_store_handler();
1865 			build_r3000_tlb_modify_handler();
1866 			run_once++;
1867 		}
1868 		break;
1869 
1870 	case CPU_R6000:
1871 	case CPU_R6000A:
1872 		panic("No R6000 TLB refill handler yet");
1873 		break;
1874 
1875 	case CPU_R8000:
1876 		panic("No R8000 TLB refill handler yet");
1877 		break;
1878 
1879 	default:
1880 		build_r4000_tlb_refill_handler();
1881 		if (!run_once) {
1882 			build_r4000_tlb_load_handler();
1883 			build_r4000_tlb_store_handler();
1884 			build_r4000_tlb_modify_handler();
1885 			run_once++;
1886 		}
1887 	}
1888 }
1889 
1890 void __init flush_tlb_handlers(void)
1891 {
1892 	flush_icache_range((unsigned long)handle_tlbl,
1893 			   (unsigned long)handle_tlbl + sizeof(handle_tlbl));
1894 	flush_icache_range((unsigned long)handle_tlbs,
1895 			   (unsigned long)handle_tlbs + sizeof(handle_tlbs));
1896 	flush_icache_range((unsigned long)handle_tlbm,
1897 			   (unsigned long)handle_tlbm + sizeof(handle_tlbm));
1898 }
1899