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  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 <stdarg.h>
23
24#include <linux/mm.h>
25#include <linux/kernel.h>
26#include <linux/types.h>
27#include <linux/string.h>
28#include <linux/init.h>
29
30#include <asm/pgtable.h>
31#include <asm/cacheflush.h>
32#include <asm/mmu_context.h>
33#include <asm/inst.h>
34#include <asm/elf.h>
35#include <asm/smp.h>
36#include <asm/war.h>
37
38static __init int __maybe_unused r45k_bvahwbug(void)
39{
40	return 0;
41}
42
43static __init int __maybe_unused r4k_250MHZhwbug(void)
44{
45	return 0;
46}
47
48static __init int __maybe_unused bcm1250_m3_war(void)
49{
50	return BCM1250_M3_WAR;
51}
52
53static __init int __maybe_unused r10000_llsc_war(void)
54{
55	return R10000_LLSC_WAR;
56}
57
58/*
59 * A little micro-assembler, intended for TLB refill handler
60 * synthesizing. It is intentionally kept simple, does only support
61 * a subset of instructions, and does not try to hide pipeline effects
62 * like branch delay slots.
63 */
64
65enum fields
66{
67	RS = 0x001,
68	RT = 0x002,
69	RD = 0x004,
70	RE = 0x008,
71	SIMM = 0x010,
72	UIMM = 0x020,
73	BIMM = 0x040,
74	JIMM = 0x080,
75	FUNC = 0x100,
76	SET = 0x200
77};
78
79#define OP_MASK		0x2f
80#define OP_SH		26
81#define RS_MASK		0x1f
82#define RS_SH		21
83#define RT_MASK		0x1f
84#define RT_SH		16
85#define RD_MASK		0x1f
86#define RD_SH		11
87#define RE_MASK		0x1f
88#define RE_SH		6
89#define IMM_MASK	0xffff
90#define IMM_SH		0
91#define JIMM_MASK	0x3ffffff
92#define JIMM_SH		0
93#define FUNC_MASK	0x2f
94#define FUNC_SH		0
95#define SET_MASK	0x7
96#define SET_SH		0
97
98enum opcode {
99	insn_invalid,
100	insn_addu, insn_addiu, insn_and, insn_andi, insn_beq,
101	insn_beql, insn_bgez, insn_bgezl, insn_bltz, insn_bltzl,
102	insn_bne, insn_daddu, insn_daddiu, insn_dmfc0, insn_dmtc0,
103	insn_dsll, insn_dsll32, insn_dsra, insn_dsrl, insn_dsrl32,
104	insn_dsubu, insn_eret, insn_j, insn_jal, insn_jr, insn_ld,
105	insn_ll, insn_lld, insn_lui, insn_lw, insn_mfc0, insn_mtc0,
106	insn_ori, insn_rfe, insn_sc, insn_scd, insn_sd, insn_sll,
107	insn_sra, insn_srl, insn_subu, insn_sw, insn_tlbp, insn_tlbwi,
108	insn_tlbwr, insn_xor, insn_xori
109};
110
111struct insn {
112	enum opcode opcode;
113	u32 match;
114	enum fields fields;
115};
116
117/* This macro sets the non-variable bits of an instruction. */
118#define M(a, b, c, d, e, f)					\
119	((a) << OP_SH						\
120	 | (b) << RS_SH						\
121	 | (c) << RT_SH						\
122	 | (d) << RD_SH						\
123	 | (e) << RE_SH						\
124	 | (f) << FUNC_SH)
125
126static __initdata struct insn insn_table[] = {
127	{ insn_addiu, M(addiu_op,0,0,0,0,0), RS | RT | SIMM },
128	{ insn_addu, M(spec_op,0,0,0,0,addu_op), RS | RT | RD },
129	{ insn_and, M(spec_op,0,0,0,0,and_op), RS | RT | RD },
130	{ insn_andi, M(andi_op,0,0,0,0,0), RS | RT | UIMM },
131	{ insn_beq, M(beq_op,0,0,0,0,0), RS | RT | BIMM },
132	{ insn_beql, M(beql_op,0,0,0,0,0), RS | RT | BIMM },
133	{ insn_bgez, M(bcond_op,0,bgez_op,0,0,0), RS | BIMM },
134	{ insn_bgezl, M(bcond_op,0,bgezl_op,0,0,0), RS | BIMM },
135	{ insn_bltz, M(bcond_op,0,bltz_op,0,0,0), RS | BIMM },
136	{ insn_bltzl, M(bcond_op,0,bltzl_op,0,0,0), RS | BIMM },
137	{ insn_bne, M(bne_op,0,0,0,0,0), RS | RT | BIMM },
138	{ insn_daddiu, M(daddiu_op,0,0,0,0,0), RS | RT | SIMM },
139	{ insn_daddu, M(spec_op,0,0,0,0,daddu_op), RS | RT | RD },
140	{ insn_dmfc0, M(cop0_op,dmfc_op,0,0,0,0), RT | RD | SET},
141	{ insn_dmtc0, M(cop0_op,dmtc_op,0,0,0,0), RT | RD | SET},
142	{ insn_dsll, M(spec_op,0,0,0,0,dsll_op), RT | RD | RE },
143	{ insn_dsll32, M(spec_op,0,0,0,0,dsll32_op), RT | RD | RE },
144	{ insn_dsra, M(spec_op,0,0,0,0,dsra_op), RT | RD | RE },
145	{ insn_dsrl, M(spec_op,0,0,0,0,dsrl_op), RT | RD | RE },
146	{ insn_dsrl32, M(spec_op,0,0,0,0,dsrl32_op), RT | RD | RE },
147	{ insn_dsubu, M(spec_op,0,0,0,0,dsubu_op), RS | RT | RD },
148	{ insn_eret, M(cop0_op,cop_op,0,0,0,eret_op), 0 },
149	{ insn_j, M(j_op,0,0,0,0,0), JIMM },
150	{ insn_jal, M(jal_op,0,0,0,0,0), JIMM },
151	{ insn_jr, M(spec_op,0,0,0,0,jr_op), RS },
152	{ insn_ld, M(ld_op,0,0,0,0,0), RS | RT | SIMM },
153	{ insn_ll, M(ll_op,0,0,0,0,0), RS | RT | SIMM },
154	{ insn_lld, M(lld_op,0,0,0,0,0), RS | RT | SIMM },
155	{ insn_lui, M(lui_op,0,0,0,0,0), RT | SIMM },
156	{ insn_lw, M(lw_op,0,0,0,0,0), RS | RT | SIMM },
157	{ insn_mfc0, M(cop0_op,mfc_op,0,0,0,0), RT | RD | SET},
158	{ insn_mtc0, M(cop0_op,mtc_op,0,0,0,0), RT | RD | SET},
159	{ insn_ori, M(ori_op,0,0,0,0,0), RS | RT | UIMM },
160	{ insn_rfe, M(cop0_op,cop_op,0,0,0,rfe_op), 0 },
161	{ insn_sc, M(sc_op,0,0,0,0,0), RS | RT | SIMM },
162	{ insn_scd, M(scd_op,0,0,0,0,0), RS | RT | SIMM },
163	{ insn_sd, M(sd_op,0,0,0,0,0), RS | RT | SIMM },
164	{ insn_sll, M(spec_op,0,0,0,0,sll_op), RT | RD | RE },
165	{ insn_sra, M(spec_op,0,0,0,0,sra_op), RT | RD | RE },
166	{ insn_srl, M(spec_op,0,0,0,0,srl_op), RT | RD | RE },
167	{ insn_subu, M(spec_op,0,0,0,0,subu_op), RS | RT | RD },
168	{ insn_sw, M(sw_op,0,0,0,0,0), RS | RT | SIMM },
169	{ insn_tlbp, M(cop0_op,cop_op,0,0,0,tlbp_op), 0 },
170	{ insn_tlbwi, M(cop0_op,cop_op,0,0,0,tlbwi_op), 0 },
171	{ insn_tlbwr, M(cop0_op,cop_op,0,0,0,tlbwr_op), 0 },
172	{ insn_xor, M(spec_op,0,0,0,0,xor_op), RS | RT | RD },
173	{ insn_xori, M(xori_op,0,0,0,0,0), RS | RT | UIMM },
174	{ insn_invalid, 0, 0 }
175};
176
177#undef M
178
179static __init u32 build_rs(u32 arg)
180{
181	if (arg & ~RS_MASK)
182		printk(KERN_WARNING "TLB synthesizer field overflow\n");
183
184	return (arg & RS_MASK) << RS_SH;
185}
186
187static __init u32 build_rt(u32 arg)
188{
189	if (arg & ~RT_MASK)
190		printk(KERN_WARNING "TLB synthesizer field overflow\n");
191
192	return (arg & RT_MASK) << RT_SH;
193}
194
195static __init u32 build_rd(u32 arg)
196{
197	if (arg & ~RD_MASK)
198		printk(KERN_WARNING "TLB synthesizer field overflow\n");
199
200	return (arg & RD_MASK) << RD_SH;
201}
202
203static __init u32 build_re(u32 arg)
204{
205	if (arg & ~RE_MASK)
206		printk(KERN_WARNING "TLB synthesizer field overflow\n");
207
208	return (arg & RE_MASK) << RE_SH;
209}
210
211static __init u32 build_simm(s32 arg)
212{
213	if (arg > 0x7fff || arg < -0x8000)
214		printk(KERN_WARNING "TLB synthesizer field overflow\n");
215
216	return arg & 0xffff;
217}
218
219static __init u32 build_uimm(u32 arg)
220{
221	if (arg & ~IMM_MASK)
222		printk(KERN_WARNING "TLB synthesizer field overflow\n");
223
224	return arg & IMM_MASK;
225}
226
227static __init u32 build_bimm(s32 arg)
228{
229	if (arg > 0x1ffff || arg < -0x20000)
230		printk(KERN_WARNING "TLB synthesizer field overflow\n");
231
232	if (arg & 0x3)
233		printk(KERN_WARNING "Invalid TLB synthesizer branch target\n");
234
235	return ((arg < 0) ? (1 << 15) : 0) | ((arg >> 2) & 0x7fff);
236}
237
238static __init u32 build_jimm(u32 arg)
239{
240	if (arg & ~((JIMM_MASK) << 2))
241		printk(KERN_WARNING "TLB synthesizer field overflow\n");
242
243	return (arg >> 2) & JIMM_MASK;
244}
245
246static __init u32 build_func(u32 arg)
247{
248	if (arg & ~FUNC_MASK)
249		printk(KERN_WARNING "TLB synthesizer field overflow\n");
250
251	return arg & FUNC_MASK;
252}
253
254static __init u32 build_set(u32 arg)
255{
256	if (arg & ~SET_MASK)
257		printk(KERN_WARNING "TLB synthesizer field overflow\n");
258
259	return arg & SET_MASK;
260}
261
262/*
263 * The order of opcode arguments is implicitly left to right,
264 * starting with RS and ending with FUNC or IMM.
265 */
266static void __init build_insn(u32 **buf, enum opcode opc, ...)
267{
268	struct insn *ip = NULL;
269	unsigned int i;
270	va_list ap;
271	u32 op;
272
273	for (i = 0; insn_table[i].opcode != insn_invalid; i++)
274		if (insn_table[i].opcode == opc) {
275			ip = &insn_table[i];
276			break;
277		}
278
279	if (!ip)
280		panic("Unsupported TLB synthesizer instruction %d", opc);
281
282	op = ip->match;
283	va_start(ap, opc);
284	if (ip->fields & RS) op |= build_rs(va_arg(ap, u32));
285	if (ip->fields & RT) op |= build_rt(va_arg(ap, u32));
286	if (ip->fields & RD) op |= build_rd(va_arg(ap, u32));
287	if (ip->fields & RE) op |= build_re(va_arg(ap, u32));
288	if (ip->fields & SIMM) op |= build_simm(va_arg(ap, s32));
289	if (ip->fields & UIMM) op |= build_uimm(va_arg(ap, u32));
290	if (ip->fields & BIMM) op |= build_bimm(va_arg(ap, s32));
291	if (ip->fields & JIMM) op |= build_jimm(va_arg(ap, u32));
292	if (ip->fields & FUNC) op |= build_func(va_arg(ap, u32));
293	if (ip->fields & SET) op |= build_set(va_arg(ap, u32));
294	va_end(ap);
295
296	**buf = op;
297	(*buf)++;
298}
299
300#define I_u1u2u3(op)						\
301	static inline void __init i##op(u32 **buf, unsigned int a,	\
302	 	unsigned int b, unsigned int c)			\
303	{							\
304		build_insn(buf, insn##op, a, b, c);		\
305	}
306
307#define I_u2u1u3(op)						\
308	static inline void __init i##op(u32 **buf, unsigned int a,	\
309	 	unsigned int b, unsigned int c)			\
310	{							\
311		build_insn(buf, insn##op, b, a, c);		\
312	}
313
314#define I_u3u1u2(op)						\
315	static inline void __init i##op(u32 **buf, unsigned int a,	\
316	 	unsigned int b, unsigned int c)			\
317	{							\
318		build_insn(buf, insn##op, b, c, a);		\
319	}
320
321#define I_u1u2s3(op)						\
322	static inline void __init i##op(u32 **buf, unsigned int a,	\
323	 	unsigned int b, signed int c)			\
324	{							\
325		build_insn(buf, insn##op, a, b, c);		\
326	}
327
328#define I_u2s3u1(op)						\
329	static inline void __init i##op(u32 **buf, unsigned int a,	\
330	 	signed int b, unsigned int c)			\
331	{							\
332		build_insn(buf, insn##op, c, a, b);		\
333	}
334
335#define I_u2u1s3(op)						\
336	static inline void __init i##op(u32 **buf, unsigned int a,	\
337	 	unsigned int b, signed int c)			\
338	{							\
339		build_insn(buf, insn##op, b, a, c);		\
340	}
341
342#define I_u1u2(op)						\
343	static inline void __init i##op(u32 **buf, unsigned int a,	\
344	 	unsigned int b)					\
345	{							\
346		build_insn(buf, insn##op, a, b);		\
347	}
348
349#define I_u1s2(op)						\
350	static inline void __init i##op(u32 **buf, unsigned int a,	\
351	 	signed int b)					\
352	{							\
353		build_insn(buf, insn##op, a, b);		\
354	}
355
356#define I_u1(op)						\
357	static inline void __init i##op(u32 **buf, unsigned int a)	\
358	{							\
359		build_insn(buf, insn##op, a);			\
360	}
361
362#define I_0(op)							\
363	static inline void __init i##op(u32 **buf)		\
364	{							\
365		build_insn(buf, insn##op);			\
366	}
367
368I_u2u1s3(_addiu);
369I_u3u1u2(_addu);
370I_u2u1u3(_andi);
371I_u3u1u2(_and);
372I_u1u2s3(_beq);
373I_u1u2s3(_beql);
374I_u1s2(_bgez);
375I_u1s2(_bgezl);
376I_u1s2(_bltz);
377I_u1s2(_bltzl);
378I_u1u2s3(_bne);
379I_u1u2u3(_dmfc0);
380I_u1u2u3(_dmtc0);
381I_u2u1s3(_daddiu);
382I_u3u1u2(_daddu);
383I_u2u1u3(_dsll);
384I_u2u1u3(_dsll32);
385I_u2u1u3(_dsra);
386I_u2u1u3(_dsrl);
387I_u2u1u3(_dsrl32);
388I_u3u1u2(_dsubu);
389I_0(_eret);
390I_u1(_j);
391I_u1(_jal);
392I_u1(_jr);
393I_u2s3u1(_ld);
394I_u2s3u1(_ll);
395I_u2s3u1(_lld);
396I_u1s2(_lui);
397I_u2s3u1(_lw);
398I_u1u2u3(_mfc0);
399I_u1u2u3(_mtc0);
400I_u2u1u3(_ori);
401I_0(_rfe);
402I_u2s3u1(_sc);
403I_u2s3u1(_scd);
404I_u2s3u1(_sd);
405I_u2u1u3(_sll);
406I_u2u1u3(_sra);
407I_u2u1u3(_srl);
408I_u3u1u2(_subu);
409I_u2s3u1(_sw);
410I_0(_tlbp);
411I_0(_tlbwi);
412I_0(_tlbwr);
413I_u3u1u2(_xor)
414I_u2u1u3(_xori);
415
416/*
417 * handling labels
418 */
419
420enum label_id {
421	label_invalid,
422	label_second_part,
423	label_leave,
424#ifdef MODULE_START
425	label_module_alloc,
426#endif
427	label_vmalloc,
428	label_vmalloc_done,
429	label_tlbw_hazard,
430	label_split,
431	label_nopage_tlbl,
432	label_nopage_tlbs,
433	label_nopage_tlbm,
434	label_smp_pgtable_change,
435	label_r3000_write_probe_fail,
436};
437
438struct label {
439	u32 *addr;
440	enum label_id lab;
441};
442
443static __init void build_label(struct label **lab, u32 *addr,
444			       enum label_id l)
445{
446	(*lab)->addr = addr;
447	(*lab)->lab = l;
448	(*lab)++;
449}
450
451#define L_LA(lb)						\
452	static inline void l##lb(struct label **lab, u32 *addr) \
453	{							\
454		build_label(lab, addr, label##lb);		\
455	}
456
457L_LA(_second_part)
458L_LA(_leave)
459#ifdef MODULE_START
460L_LA(_module_alloc)
461#endif
462L_LA(_vmalloc)
463L_LA(_vmalloc_done)
464L_LA(_tlbw_hazard)
465L_LA(_split)
466L_LA(_nopage_tlbl)
467L_LA(_nopage_tlbs)
468L_LA(_nopage_tlbm)
469L_LA(_smp_pgtable_change)
470L_LA(_r3000_write_probe_fail)
471
472/* convenience macros for instructions */
473#ifdef CONFIG_64BIT
474# define i_LW(buf, rs, rt, off) i_ld(buf, rs, rt, off)
475# define i_SW(buf, rs, rt, off) i_sd(buf, rs, rt, off)
476# define i_SLL(buf, rs, rt, sh) i_dsll(buf, rs, rt, sh)
477# define i_SRA(buf, rs, rt, sh) i_dsra(buf, rs, rt, sh)
478# define i_SRL(buf, rs, rt, sh) i_dsrl(buf, rs, rt, sh)
479# define i_MFC0(buf, rt, rd...) i_dmfc0(buf, rt, rd)
480# define i_MTC0(buf, rt, rd...) i_dmtc0(buf, rt, rd)
481# define i_ADDIU(buf, rs, rt, val) i_daddiu(buf, rs, rt, val)
482# define i_ADDU(buf, rs, rt, rd) i_daddu(buf, rs, rt, rd)
483# define i_SUBU(buf, rs, rt, rd) i_dsubu(buf, rs, rt, rd)
484# define i_LL(buf, rs, rt, off) i_lld(buf, rs, rt, off)
485# define i_SC(buf, rs, rt, off) i_scd(buf, rs, rt, off)
486#else
487# define i_LW(buf, rs, rt, off) i_lw(buf, rs, rt, off)
488# define i_SW(buf, rs, rt, off) i_sw(buf, rs, rt, off)
489# define i_SLL(buf, rs, rt, sh) i_sll(buf, rs, rt, sh)
490# define i_SRA(buf, rs, rt, sh) i_sra(buf, rs, rt, sh)
491# define i_SRL(buf, rs, rt, sh) i_srl(buf, rs, rt, sh)
492# define i_MFC0(buf, rt, rd...) i_mfc0(buf, rt, rd)
493# define i_MTC0(buf, rt, rd...) i_mtc0(buf, rt, rd)
494# define i_ADDIU(buf, rs, rt, val) i_addiu(buf, rs, rt, val)
495# define i_ADDU(buf, rs, rt, rd) i_addu(buf, rs, rt, rd)
496# define i_SUBU(buf, rs, rt, rd) i_subu(buf, rs, rt, rd)
497# define i_LL(buf, rs, rt, off) i_ll(buf, rs, rt, off)
498# define i_SC(buf, rs, rt, off) i_sc(buf, rs, rt, off)
499#endif
500
501#define i_b(buf, off) i_beq(buf, 0, 0, off)
502#define i_beqz(buf, rs, off) i_beq(buf, rs, 0, off)
503#define i_beqzl(buf, rs, off) i_beql(buf, rs, 0, off)
504#define i_bnez(buf, rs, off) i_bne(buf, rs, 0, off)
505#define i_bnezl(buf, rs, off) i_bnel(buf, rs, 0, off)
506#define i_move(buf, a, b) i_ADDU(buf, a, 0, b)
507#define i_nop(buf) i_sll(buf, 0, 0, 0)
508#define i_ssnop(buf) i_sll(buf, 0, 0, 1)
509#define i_ehb(buf) i_sll(buf, 0, 0, 3)
510
511#ifdef CONFIG_64BIT
512static __init int __maybe_unused in_compat_space_p(long addr)
513{
514	/* Is this address in 32bit compat space? */
515	return (((addr) & 0xffffffff00000000L) == 0xffffffff00000000L);
516}
517
518static __init int __maybe_unused rel_highest(long val)
519{
520	return ((((val + 0x800080008000L) >> 48) & 0xffff) ^ 0x8000) - 0x8000;
521}
522
523static __init int __maybe_unused rel_higher(long val)
524{
525	return ((((val + 0x80008000L) >> 32) & 0xffff) ^ 0x8000) - 0x8000;
526}
527#endif
528
529static __init int rel_hi(long val)
530{
531	return ((((val + 0x8000L) >> 16) & 0xffff) ^ 0x8000) - 0x8000;
532}
533
534static __init int rel_lo(long val)
535{
536	return ((val & 0xffff) ^ 0x8000) - 0x8000;
537}
538
539static __init void i_LA_mostly(u32 **buf, unsigned int rs, long addr)
540{
541#ifdef CONFIG_64BIT
542	if (!in_compat_space_p(addr)) {
543		i_lui(buf, rs, rel_highest(addr));
544		if (rel_higher(addr))
545			i_daddiu(buf, rs, rs, rel_higher(addr));
546		if (rel_hi(addr)) {
547			i_dsll(buf, rs, rs, 16);
548			i_daddiu(buf, rs, rs, rel_hi(addr));
549			i_dsll(buf, rs, rs, 16);
550		} else
551			i_dsll32(buf, rs, rs, 0);
552	} else
553#endif
554		i_lui(buf, rs, rel_hi(addr));
555}
556
557static __init void __maybe_unused i_LA(u32 **buf, unsigned int rs,
558					     long addr)
559{
560	i_LA_mostly(buf, rs, addr);
561	if (rel_lo(addr))
562		i_ADDIU(buf, rs, rs, rel_lo(addr));
563}
564
565/*
566 * handle relocations
567 */
568
569struct reloc {
570	u32 *addr;
571	unsigned int type;
572	enum label_id lab;
573};
574
575static __init void r_mips_pc16(struct reloc **rel, u32 *addr,
576			       enum label_id l)
577{
578	(*rel)->addr = addr;
579	(*rel)->type = R_MIPS_PC16;
580	(*rel)->lab = l;
581	(*rel)++;
582}
583
584static inline void __resolve_relocs(struct reloc *rel, struct label *lab)
585{
586	long laddr = (long)lab->addr;
587	long raddr = (long)rel->addr;
588
589	switch (rel->type) {
590	case R_MIPS_PC16:
591		*rel->addr |= build_bimm(laddr - (raddr + 4));
592		break;
593
594	default:
595		panic("Unsupported TLB synthesizer relocation %d",
596		      rel->type);
597	}
598}
599
600static __init void resolve_relocs(struct reloc *rel, struct label *lab)
601{
602	struct label *l;
603
604	for (; rel->lab != label_invalid; rel++)
605		for (l = lab; l->lab != label_invalid; l++)
606			if (rel->lab == l->lab)
607				__resolve_relocs(rel, l);
608}
609
610static __init void move_relocs(struct reloc *rel, u32 *first, u32 *end,
611			       long off)
612{
613	for (; rel->lab != label_invalid; rel++)
614		if (rel->addr >= first && rel->addr < end)
615			rel->addr += off;
616}
617
618static __init void move_labels(struct label *lab, u32 *first, u32 *end,
619			       long off)
620{
621	for (; lab->lab != label_invalid; lab++)
622		if (lab->addr >= first && lab->addr < end)
623			lab->addr += off;
624}
625
626static __init void copy_handler(struct reloc *rel, struct label *lab,
627				u32 *first, u32 *end, u32 *target)
628{
629	long off = (long)(target - first);
630
631	memcpy(target, first, (end - first) * sizeof(u32));
632
633	move_relocs(rel, first, end, off);
634	move_labels(lab, first, end, off);
635}
636
637static __init int __maybe_unused insn_has_bdelay(struct reloc *rel,
638						       u32 *addr)
639{
640	for (; rel->lab != label_invalid; rel++) {
641		if (rel->addr == addr
642		    && (rel->type == R_MIPS_PC16
643			|| rel->type == R_MIPS_26))
644			return 1;
645	}
646
647	return 0;
648}
649
650/* convenience functions for labeled branches */
651static void __init __maybe_unused
652	il_bltz(u32 **p, struct reloc **r, unsigned int reg, enum label_id l)
653{
654	r_mips_pc16(r, *p, l);
655	i_bltz(p, reg, 0);
656}
657
658static void __init __maybe_unused il_b(u32 **p, struct reloc **r,
659					     enum label_id l)
660{
661	r_mips_pc16(r, *p, l);
662	i_b(p, 0);
663}
664
665static void __init il_beqz(u32 **p, struct reloc **r, unsigned int reg,
666		    enum label_id l)
667{
668	r_mips_pc16(r, *p, l);
669	i_beqz(p, reg, 0);
670}
671
672static void __init __maybe_unused
673il_beqzl(u32 **p, struct reloc **r, unsigned int reg, enum label_id l)
674{
675	r_mips_pc16(r, *p, l);
676	i_beqzl(p, reg, 0);
677}
678
679static void __init il_bnez(u32 **p, struct reloc **r, unsigned int reg,
680		    enum label_id l)
681{
682	r_mips_pc16(r, *p, l);
683	i_bnez(p, reg, 0);
684}
685
686static void __init il_bgezl(u32 **p, struct reloc **r, unsigned int reg,
687		     enum label_id l)
688{
689	r_mips_pc16(r, *p, l);
690	i_bgezl(p, reg, 0);
691}
692
693static void __init __maybe_unused
694il_bgez(u32 **p, struct reloc **r, unsigned int reg, enum label_id l)
695{
696	r_mips_pc16(r, *p, l);
697	i_bgez(p, reg, 0);
698}
699
700/* The only general purpose registers allowed in TLB handlers. */
701#define K0		26
702#define K1		27
703
704/* Some CP0 registers */
705#define C0_INDEX	0, 0
706#define C0_ENTRYLO0	2, 0
707#define C0_TCBIND	2, 2
708#define C0_ENTRYLO1	3, 0
709#define C0_CONTEXT	4, 0
710#define C0_BADVADDR	8, 0
711#define C0_ENTRYHI	10, 0
712#define C0_EPC		14, 0
713#define C0_XCONTEXT	20, 0
714
715#ifdef CONFIG_64BIT
716# define GET_CONTEXT(buf, reg) i_MFC0(buf, reg, C0_XCONTEXT)
717#else
718# define GET_CONTEXT(buf, reg) i_MFC0(buf, reg, C0_CONTEXT)
719#endif
720
721/* The worst case length of the handler is around 18 instructions for
722 * R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
723 * Maximum space available is 32 instructions for R3000 and 64
724 * instructions for R4000.
725 *
726 * We deliberately chose a buffer size of 128, so we won't scribble
727 * over anything important on overflow before we panic.
728 */
729static __initdata u32 tlb_handler[128];
730
731/* simply assume worst case size for labels and relocs */
732static __initdata struct label labels[128];
733static __initdata struct reloc relocs[128];
734
735/*
736 * The R3000 TLB handler is simple.
737 */
738static void __init build_r3000_tlb_refill_handler(void)
739{
740	long pgdc = (long)pgd_current;
741	u32 *p;
742	int i;
743
744	memset(tlb_handler, 0, sizeof(tlb_handler));
745	p = tlb_handler;
746
747	i_mfc0(&p, K0, C0_BADVADDR);
748	i_lui(&p, K1, rel_hi(pgdc)); /* cp0 delay */
749	i_lw(&p, K1, rel_lo(pgdc), K1);
750	i_srl(&p, K0, K0, 22); /* load delay */
751	i_sll(&p, K0, K0, 2);
752	i_addu(&p, K1, K1, K0);
753	i_mfc0(&p, K0, C0_CONTEXT);
754	i_lw(&p, K1, 0, K1); /* cp0 delay */
755	i_andi(&p, K0, K0, 0xffc); /* load delay */
756	i_addu(&p, K1, K1, K0);
757	i_lw(&p, K0, 0, K1);
758	i_nop(&p); /* load delay */
759	i_mtc0(&p, K0, C0_ENTRYLO0);
760	i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
761	i_tlbwr(&p); /* cp0 delay */
762	i_jr(&p, K1);
763	i_rfe(&p); /* branch delay */
764
765	if (p > tlb_handler + 32)
766		panic("TLB refill handler space exceeded");
767
768	pr_info("Synthesized TLB refill handler (%u instructions).\n",
769		(unsigned int)(p - tlb_handler));
770
771	pr_debug("\t.set push\n");
772	pr_debug("\t.set noreorder\n");
773	for (i = 0; i < (p - tlb_handler); i++)
774		pr_debug("\t.word 0x%08x\n", tlb_handler[i]);
775	pr_debug("\t.set pop\n");
776
777	memcpy((void *)ebase, tlb_handler, 0x80);
778}
779
780/*
781 * The R4000 TLB handler is much more complicated. We have two
782 * consecutive handler areas with 32 instructions space each.
783 * Since they aren't used at the same time, we can overflow in the
784 * other one.To keep things simple, we first assume linear space,
785 * then we relocate it to the final handler layout as needed.
786 */
787static __initdata u32 final_handler[64];
788
789static __init void __maybe_unused build_tlb_probe_entry(u32 **p)
790{
791	switch (current_cpu_data.cputype) {
792	/* Found by experiment: R4600 v2.0 needs this, too.  */
793	case CPU_R4600:
794	case CPU_R5000:
795	case CPU_R5000A:
796	case CPU_NEVADA:
797		i_nop(p);
798		i_tlbp(p);
799		break;
800
801	default:
802		i_tlbp(p);
803		break;
804	}
805}
806
807/*
808 * Write random or indexed TLB entry, and care about the hazards from
809 * the preceeding mtc0 and for the following eret.
810 */
811enum tlb_write_entry { tlb_random, tlb_indexed };
812
813static __init void build_tlb_write_entry(u32 **p, struct label **l,
814					 struct reloc **r,
815					 enum tlb_write_entry wmode)
816{
817	void(*tlbw)(u32 **) = NULL;
818
819	switch (wmode) {
820	case tlb_random: tlbw = i_tlbwr; break;
821	case tlb_indexed: tlbw = i_tlbwi; break;
822	}
823
824	switch (current_cpu_data.cputype) {
825	case CPU_R4000PC:
826	case CPU_R4000SC:
827	case CPU_R4000MC:
828	case CPU_R4400PC:
829	case CPU_R4400SC:
830	case CPU_R4400MC:
831		/*
832		 * This branch uses up a mtc0 hazard nop slot and saves
833		 * two nops after the tlbw instruction.
834		 */
835		il_bgezl(p, r, 0, label_tlbw_hazard);
836		tlbw(p);
837		l_tlbw_hazard(l, *p);
838		i_nop(p);
839		break;
840
841	case CPU_R4600:
842	case CPU_R4700:
843	case CPU_R5000:
844	case CPU_R5000A:
845		i_nop(p);
846		tlbw(p);
847		i_nop(p);
848		break;
849
850	case CPU_R4300:
851	case CPU_5KC:
852	case CPU_TX49XX:
853	case CPU_AU1000:
854	case CPU_AU1100:
855	case CPU_AU1500:
856	case CPU_AU1550:
857	case CPU_AU1200:
858	case CPU_PR4450:
859		i_nop(p);
860		tlbw(p);
861		break;
862
863	case CPU_R10000:
864	case CPU_R12000:
865	case CPU_R14000:
866	case CPU_4KC:
867	case CPU_SB1:
868	case CPU_SB1A:
869	case CPU_4KSC:
870	case CPU_20KC:
871	case CPU_25KF:
872	case CPU_BCM4710:
873	case CPU_BCM3302:
874		tlbw(p);
875		break;
876
877	case CPU_NEVADA:
878		i_nop(p); /* QED specifies 2 nops hazard */
879		/*
880		 * This branch uses up a mtc0 hazard nop slot and saves
881		 * a nop after the tlbw instruction.
882		 */
883		il_bgezl(p, r, 0, label_tlbw_hazard);
884		tlbw(p);
885		l_tlbw_hazard(l, *p);
886		break;
887
888	case CPU_RM7000:
889		i_nop(p);
890		i_nop(p);
891		i_nop(p);
892		i_nop(p);
893		tlbw(p);
894		break;
895
896	case CPU_4KEC:
897	case CPU_24K:
898	case CPU_34K:
899	case CPU_74K:
900		i_ehb(p);
901		tlbw(p);
902		break;
903
904	case CPU_RM9000:
905		/*
906		 * When the JTLB is updated by tlbwi or tlbwr, a subsequent
907		 * use of the JTLB for instructions should not occur for 4
908		 * cpu cycles and use for data translations should not occur
909		 * for 3 cpu cycles.
910		 */
911		i_ssnop(p);
912		i_ssnop(p);
913		i_ssnop(p);
914		i_ssnop(p);
915		tlbw(p);
916		i_ssnop(p);
917		i_ssnop(p);
918		i_ssnop(p);
919		i_ssnop(p);
920		break;
921
922	case CPU_VR4111:
923	case CPU_VR4121:
924	case CPU_VR4122:
925	case CPU_VR4181:
926	case CPU_VR4181A:
927		i_nop(p);
928		i_nop(p);
929		tlbw(p);
930		i_nop(p);
931		i_nop(p);
932		break;
933
934	case CPU_VR4131:
935	case CPU_VR4133:
936	case CPU_R5432:
937		i_nop(p);
938		i_nop(p);
939		tlbw(p);
940		break;
941
942	default:
943		panic("No TLB refill handler yet (CPU type: %d)",
944		      current_cpu_data.cputype);
945		break;
946	}
947}
948
949#ifdef CONFIG_64BIT
950/*
951 * TMP and PTR are scratch.
952 * TMP will be clobbered, PTR will hold the pmd entry.
953 */
954static __init void
955build_get_pmde64(u32 **p, struct label **l, struct reloc **r,
956		 unsigned int tmp, unsigned int ptr)
957{
958	long pgdc = (long)pgd_current;
959
960	/*
961	 * The vmalloc handling is not in the hotpath.
962	 */
963	i_dmfc0(p, tmp, C0_BADVADDR);
964#ifdef MODULE_START
965	il_bltz(p, r, tmp, label_module_alloc);
966#else
967	il_bltz(p, r, tmp, label_vmalloc);
968#endif
969	/* No i_nop needed here, since the next insn doesn't touch TMP. */
970
971#ifdef CONFIG_SMP
972# ifdef  CONFIG_MIPS_MT_SMTC
973	/*
974	 * SMTC uses TCBind value as "CPU" index
975	 */
976	i_mfc0(p, ptr, C0_TCBIND);
977	i_dsrl(p, ptr, ptr, 19);
978# else
979	/*
980	 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
981	 * stored in CONTEXT.
982	 */
983	i_dmfc0(p, ptr, C0_CONTEXT);
984	i_dsrl(p, ptr, ptr, 23);
985#endif
986	i_LA_mostly(p, tmp, pgdc);
987	i_daddu(p, ptr, ptr, tmp);
988	i_dmfc0(p, tmp, C0_BADVADDR);
989	i_ld(p, ptr, rel_lo(pgdc), ptr);
990#else
991	i_LA_mostly(p, ptr, pgdc);
992	i_ld(p, ptr, rel_lo(pgdc), ptr);
993#endif
994
995	l_vmalloc_done(l, *p);
996
997	if (PGDIR_SHIFT - 3 < 32)		/* get pgd offset in bytes */
998		i_dsrl(p, tmp, tmp, PGDIR_SHIFT-3);
999	else
1000		i_dsrl32(p, tmp, tmp, PGDIR_SHIFT - 3 - 32);
1001
1002	i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
1003	i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
1004	i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
1005	i_ld(p, ptr, 0, ptr); /* get pmd pointer */
1006	i_dsrl(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
1007	i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
1008	i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
1009}
1010
1011/*
1012 * BVADDR is the faulting address, PTR is scratch.
1013 * PTR will hold the pgd for vmalloc.
1014 */
1015static __init void
1016build_get_pgd_vmalloc64(u32 **p, struct label **l, struct reloc **r,
1017			unsigned int bvaddr, unsigned int ptr)
1018{
1019	long swpd = (long)swapper_pg_dir;
1020
1021#ifdef MODULE_START
1022	long modd = (long)module_pg_dir;
1023
1024	l_module_alloc(l, *p);
1025	/*
1026	 * Assumption:
1027	 * VMALLOC_START >= 0xc000000000000000UL
1028	 * MODULE_START >= 0xe000000000000000UL
1029	 */
1030	i_SLL(p, ptr, bvaddr, 2);
1031	il_bgez(p, r, ptr, label_vmalloc);
1032
1033	if (in_compat_space_p(MODULE_START) && !rel_lo(MODULE_START)) {
1034		i_lui(p, ptr, rel_hi(MODULE_START)); /* delay slot */
1035	} else {
1036		/* unlikely configuration */
1037		i_nop(p); /* delay slot */
1038		i_LA(p, ptr, MODULE_START);
1039	}
1040	i_dsubu(p, bvaddr, bvaddr, ptr);
1041
1042	if (in_compat_space_p(modd) && !rel_lo(modd)) {
1043		il_b(p, r, label_vmalloc_done);
1044		i_lui(p, ptr, rel_hi(modd));
1045	} else {
1046		i_LA_mostly(p, ptr, modd);
1047		il_b(p, r, label_vmalloc_done);
1048		i_daddiu(p, ptr, ptr, rel_lo(modd));
1049	}
1050
1051	l_vmalloc(l, *p);
1052	if (in_compat_space_p(MODULE_START) && !rel_lo(MODULE_START) &&
1053	    MODULE_START << 32 == VMALLOC_START)
1054		i_dsll32(p, ptr, ptr, 0);	/* typical case */
1055	else
1056		i_LA(p, ptr, VMALLOC_START);
1057#else
1058	l_vmalloc(l, *p);
1059	i_LA(p, ptr, VMALLOC_START);
1060#endif
1061	i_dsubu(p, bvaddr, bvaddr, ptr);
1062
1063	if (in_compat_space_p(swpd) && !rel_lo(swpd)) {
1064		il_b(p, r, label_vmalloc_done);
1065		i_lui(p, ptr, rel_hi(swpd));
1066	} else {
1067		i_LA_mostly(p, ptr, swpd);
1068		il_b(p, r, label_vmalloc_done);
1069		i_daddiu(p, ptr, ptr, rel_lo(swpd));
1070	}
1071}
1072
1073#else /* !CONFIG_64BIT */
1074
1075/*
1076 * TMP and PTR are scratch.
1077 * TMP will be clobbered, PTR will hold the pgd entry.
1078 */
1079static __init void __maybe_unused
1080build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
1081{
1082	long pgdc = (long)pgd_current;
1083
1084	/* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
1085#ifdef CONFIG_SMP
1086#ifdef  CONFIG_MIPS_MT_SMTC
1087	/*
1088	 * SMTC uses TCBind value as "CPU" index
1089	 */
1090	i_mfc0(p, ptr, C0_TCBIND);
1091	i_LA_mostly(p, tmp, pgdc);
1092	i_srl(p, ptr, ptr, 19);
1093#else
1094	/*
1095	 * smp_processor_id() << 3 is stored in CONTEXT.
1096         */
1097	i_mfc0(p, ptr, C0_CONTEXT);
1098	i_LA_mostly(p, tmp, pgdc);
1099	i_srl(p, ptr, ptr, 23);
1100#endif
1101	i_addu(p, ptr, tmp, ptr);
1102#else
1103	i_LA_mostly(p, ptr, pgdc);
1104#endif
1105	i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
1106	i_lw(p, ptr, rel_lo(pgdc), ptr);
1107	i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
1108	i_sll(p, tmp, tmp, PGD_T_LOG2);
1109	i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
1110}
1111
1112#endif /* !CONFIG_64BIT */
1113
1114static __init void build_adjust_context(u32 **p, unsigned int ctx)
1115{
1116	unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
1117	unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
1118
1119	switch (current_cpu_data.cputype) {
1120	case CPU_VR41XX:
1121	case CPU_VR4111:
1122	case CPU_VR4121:
1123	case CPU_VR4122:
1124	case CPU_VR4131:
1125	case CPU_VR4181:
1126	case CPU_VR4181A:
1127	case CPU_VR4133:
1128		shift += 2;
1129		break;
1130
1131	default:
1132		break;
1133	}
1134
1135	if (shift)
1136		i_SRL(p, ctx, ctx, shift);
1137	i_andi(p, ctx, ctx, mask);
1138}
1139
1140static __init void build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
1141{
1142	switch (current_cpu_data.cputype) {
1143	case CPU_NEVADA:
1144		i_LW(p, ptr, 0, ptr);
1145		GET_CONTEXT(p, tmp); /* get context reg */
1146		break;
1147
1148	default:
1149		GET_CONTEXT(p, tmp); /* get context reg */
1150		i_LW(p, ptr, 0, ptr);
1151		break;
1152	}
1153
1154	build_adjust_context(p, tmp);
1155	i_ADDU(p, ptr, ptr, tmp); /* add in offset */
1156}
1157
1158static __init void build_update_entries(u32 **p, unsigned int tmp,
1159					unsigned int ptep)
1160{
1161	/*
1162	 * 64bit address support (36bit on a 32bit CPU) in a 32bit
1163	 * Kernel is a special case. Only a few CPUs use it.
1164	 */
1165#ifdef CONFIG_64BIT_PHYS_ADDR
1166	if (cpu_has_64bits) {
1167		i_ld(p, tmp, 0, ptep); /* get even pte */
1168		i_ld(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
1169		i_dsrl(p, tmp, tmp, 6); /* convert to entrylo0 */
1170		i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
1171		i_dsrl(p, ptep, ptep, 6); /* convert to entrylo1 */
1172		i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
1173	} else {
1174		int pte_off_even = sizeof(pte_t) / 2;
1175		int pte_off_odd = pte_off_even + sizeof(pte_t);
1176
1177		/* The pte entries are pre-shifted */
1178		i_lw(p, tmp, pte_off_even, ptep); /* get even pte */
1179		i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
1180		i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */
1181		i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
1182	}
1183#else
1184	i_LW(p, tmp, 0, ptep); /* get even pte */
1185	i_LW(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
1186	if (r45k_bvahwbug())
1187		build_tlb_probe_entry(p);
1188	i_SRL(p, tmp, tmp, 6); /* convert to entrylo0 */
1189	if (r4k_250MHZhwbug())
1190		i_mtc0(p, 0, C0_ENTRYLO0);
1191	i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
1192	i_SRL(p, ptep, ptep, 6); /* convert to entrylo1 */
1193	if (r45k_bvahwbug())
1194		i_mfc0(p, tmp, C0_INDEX);
1195	if (r4k_250MHZhwbug())
1196		i_mtc0(p, 0, C0_ENTRYLO1);
1197	i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
1198#endif
1199}
1200
1201static void __init build_r4000_tlb_refill_handler(void)
1202{
1203	u32 *p = tlb_handler;
1204	struct label *l = labels;
1205	struct reloc *r = relocs;
1206	u32 *f;
1207	unsigned int final_len;
1208	int i;
1209
1210	memset(tlb_handler, 0, sizeof(tlb_handler));
1211	memset(labels, 0, sizeof(labels));
1212	memset(relocs, 0, sizeof(relocs));
1213	memset(final_handler, 0, sizeof(final_handler));
1214
1215	/*
1216	 * create the plain linear handler
1217	 */
1218	if (bcm1250_m3_war()) {
1219		i_MFC0(&p, K0, C0_BADVADDR);
1220		i_MFC0(&p, K1, C0_ENTRYHI);
1221		i_xor(&p, K0, K0, K1);
1222		i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
1223		il_bnez(&p, &r, K0, label_leave);
1224		/* No need for i_nop */
1225	}
1226
1227#ifdef CONFIG_64BIT
1228	build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
1229#else
1230	build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
1231#endif
1232
1233	build_get_ptep(&p, K0, K1);
1234	build_update_entries(&p, K0, K1);
1235	build_tlb_write_entry(&p, &l, &r, tlb_random);
1236	l_leave(&l, p);
1237	i_eret(&p); /* return from trap */
1238
1239#ifdef CONFIG_64BIT
1240	build_get_pgd_vmalloc64(&p, &l, &r, K0, K1);
1241#endif
1242
1243	/*
1244	 * Overflow check: For the 64bit handler, we need at least one
1245	 * free instruction slot for the wrap-around branch. In worst
1246	 * case, if the intended insertion point is a delay slot, we
1247	 * need three, with the second nop'ed and the third being
1248	 * unused.
1249	 */
1250#ifdef CONFIG_32BIT
1251	if ((p - tlb_handler) > 64)
1252		panic("TLB refill handler space exceeded");
1253#else
1254	if (((p - tlb_handler) > 63)
1255	    || (((p - tlb_handler) > 61)
1256		&& insn_has_bdelay(relocs, tlb_handler + 29)))
1257		panic("TLB refill handler space exceeded");
1258#endif
1259
1260	/*
1261	 * Now fold the handler in the TLB refill handler space.
1262	 */
1263#ifdef CONFIG_32BIT
1264	f = final_handler;
1265	/* Simplest case, just copy the handler. */
1266	copy_handler(relocs, labels, tlb_handler, p, f);
1267	final_len = p - tlb_handler;
1268#else /* CONFIG_64BIT */
1269	f = final_handler + 32;
1270	if ((p - tlb_handler) <= 32) {
1271		/* Just copy the handler. */
1272		copy_handler(relocs, labels, tlb_handler, p, f);
1273		final_len = p - tlb_handler;
1274	} else {
1275		u32 *split = tlb_handler + 30;
1276
1277		/*
1278		 * Find the split point.
1279		 */
1280		if (insn_has_bdelay(relocs, split - 1))
1281			split--;
1282
1283		/* Copy first part of the handler. */
1284		copy_handler(relocs, labels, tlb_handler, split, f);
1285		f += split - tlb_handler;
1286
1287		/* Insert branch. */
1288		l_split(&l, final_handler);
1289		il_b(&f, &r, label_split);
1290		if (insn_has_bdelay(relocs, split))
1291			i_nop(&f);
1292		else {
1293			copy_handler(relocs, labels, split, split + 1, f);
1294			move_labels(labels, f, f + 1, -1);
1295			f++;
1296			split++;
1297		}
1298
1299		/* Copy the rest of the handler. */
1300		copy_handler(relocs, labels, split, p, final_handler);
1301		final_len = (f - (final_handler + 32)) + (p - split);
1302	}
1303#endif /* CONFIG_64BIT */
1304
1305	resolve_relocs(relocs, labels);
1306	pr_info("Synthesized TLB refill handler (%u instructions).\n",
1307		final_len);
1308
1309	f = final_handler;
1310#ifdef CONFIG_64BIT
1311	if (final_len > 32)
1312		final_len = 64;
1313	else
1314		f = final_handler + 32;
1315#endif /* CONFIG_64BIT */
1316	pr_debug("\t.set push\n");
1317	pr_debug("\t.set noreorder\n");
1318	for (i = 0; i < final_len; i++)
1319		pr_debug("\t.word 0x%08x\n", f[i]);
1320	pr_debug("\t.set pop\n");
1321
1322	memcpy((void *)ebase, final_handler, 0x100);
1323}
1324
1325/*
1326 * TLB load/store/modify handlers.
1327 *
1328 * Only the fastpath gets synthesized at runtime, the slowpath for
1329 * do_page_fault remains normal asm.
1330 */
1331extern void tlb_do_page_fault_0(void);
1332extern void tlb_do_page_fault_1(void);
1333
1334#define __tlb_handler_align \
1335	__attribute__((__aligned__(1 << CONFIG_MIPS_L1_CACHE_SHIFT)))
1336
1337/*
1338 * 128 instructions for the fastpath handler is generous and should
1339 * never be exceeded.
1340 */
1341#define FASTPATH_SIZE 128
1342
1343u32 __tlb_handler_align handle_tlbl[FASTPATH_SIZE];
1344u32 __tlb_handler_align handle_tlbs[FASTPATH_SIZE];
1345u32 __tlb_handler_align handle_tlbm[FASTPATH_SIZE];
1346
1347static void __init
1348iPTE_LW(u32 **p, struct label **l, unsigned int pte, unsigned int ptr)
1349{
1350#ifdef CONFIG_SMP
1351# ifdef CONFIG_64BIT_PHYS_ADDR
1352	if (cpu_has_64bits)
1353		i_lld(p, pte, 0, ptr);
1354	else
1355# endif
1356		i_LL(p, pte, 0, ptr);
1357#else
1358# ifdef CONFIG_64BIT_PHYS_ADDR
1359	if (cpu_has_64bits)
1360		i_ld(p, pte, 0, ptr);
1361	else
1362# endif
1363		i_LW(p, pte, 0, ptr);
1364#endif
1365}
1366
1367static void __init
1368iPTE_SW(u32 **p, struct reloc **r, unsigned int pte, unsigned int ptr,
1369	unsigned int mode)
1370{
1371#ifdef CONFIG_64BIT_PHYS_ADDR
1372	unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
1373#endif
1374
1375	i_ori(p, pte, pte, mode);
1376#ifdef CONFIG_SMP
1377# ifdef CONFIG_64BIT_PHYS_ADDR
1378	if (cpu_has_64bits)
1379		i_scd(p, pte, 0, ptr);
1380	else
1381# endif
1382		i_SC(p, pte, 0, ptr);
1383
1384	if (r10000_llsc_war())
1385		il_beqzl(p, r, pte, label_smp_pgtable_change);
1386	else
1387		il_beqz(p, r, pte, label_smp_pgtable_change);
1388
1389# ifdef CONFIG_64BIT_PHYS_ADDR
1390	if (!cpu_has_64bits) {
1391		/* no i_nop needed */
1392		i_ll(p, pte, sizeof(pte_t) / 2, ptr);
1393		i_ori(p, pte, pte, hwmode);
1394		i_sc(p, pte, sizeof(pte_t) / 2, ptr);
1395		il_beqz(p, r, pte, label_smp_pgtable_change);
1396		/* no i_nop needed */
1397		i_lw(p, pte, 0, ptr);
1398	} else
1399		i_nop(p);
1400# else
1401	i_nop(p);
1402# endif
1403#else
1404# ifdef CONFIG_64BIT_PHYS_ADDR
1405	if (cpu_has_64bits)
1406		i_sd(p, pte, 0, ptr);
1407	else
1408# endif
1409		i_SW(p, pte, 0, ptr);
1410
1411# ifdef CONFIG_64BIT_PHYS_ADDR
1412	if (!cpu_has_64bits) {
1413		i_lw(p, pte, sizeof(pte_t) / 2, ptr);
1414		i_ori(p, pte, pte, hwmode);
1415		i_sw(p, pte, sizeof(pte_t) / 2, ptr);
1416		i_lw(p, pte, 0, ptr);
1417	}
1418# endif
1419#endif
1420}
1421
1422/*
1423 * Check if PTE is present, if not then jump to LABEL. PTR points to
1424 * the page table where this PTE is located, PTE will be re-loaded
1425 * with it's original value.
1426 */
1427static void __init
1428build_pte_present(u32 **p, struct label **l, struct reloc **r,
1429		  unsigned int pte, unsigned int ptr, enum label_id lid)
1430{
1431	i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
1432	i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
1433	il_bnez(p, r, pte, lid);
1434	iPTE_LW(p, l, pte, ptr);
1435}
1436
1437/* Make PTE valid, store result in PTR. */
1438static void __init
1439build_make_valid(u32 **p, struct reloc **r, unsigned int pte,
1440		 unsigned int ptr)
1441{
1442	unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
1443
1444	iPTE_SW(p, r, pte, ptr, mode);
1445}
1446
1447/*
1448 * Check if PTE can be written to, if not branch to LABEL. Regardless
1449 * restore PTE with value from PTR when done.
1450 */
1451static void __init
1452build_pte_writable(u32 **p, struct label **l, struct reloc **r,
1453		   unsigned int pte, unsigned int ptr, enum label_id lid)
1454{
1455	i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1456	i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1457	il_bnez(p, r, pte, lid);
1458	iPTE_LW(p, l, pte, ptr);
1459}
1460
1461/* Make PTE writable, update software status bits as well, then store
1462 * at PTR.
1463 */
1464static void __init
1465build_make_write(u32 **p, struct reloc **r, unsigned int pte,
1466		 unsigned int ptr)
1467{
1468	unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1469			     | _PAGE_DIRTY);
1470
1471	iPTE_SW(p, r, pte, ptr, mode);
1472}
1473
1474/*
1475 * Check if PTE can be modified, if not branch to LABEL. Regardless
1476 * restore PTE with value from PTR when done.
1477 */
1478static void __init
1479build_pte_modifiable(u32 **p, struct label **l, struct reloc **r,
1480		     unsigned int pte, unsigned int ptr, enum label_id lid)
1481{
1482	i_andi(p, pte, pte, _PAGE_WRITE);
1483	il_beqz(p, r, pte, lid);
1484	iPTE_LW(p, l, pte, ptr);
1485}
1486
1487/*
1488 * R3000 style TLB load/store/modify handlers.
1489 */
1490
1491/*
1492 * This places the pte into ENTRYLO0 and writes it with tlbwi.
1493 * Then it returns.
1494 */
1495static void __init
1496build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1497{
1498	i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1499	i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1500	i_tlbwi(p);
1501	i_jr(p, tmp);
1502	i_rfe(p); /* branch delay */
1503}
1504
1505/*
1506 * This places the pte into ENTRYLO0 and writes it with tlbwi
1507 * or tlbwr as appropriate.  This is because the index register
1508 * may have the probe fail bit set as a result of a trap on a
1509 * kseg2 access, i.e. without refill.  Then it returns.
1510 */
1511static void __init
1512build_r3000_tlb_reload_write(u32 **p, struct label **l, struct reloc **r,
1513			     unsigned int pte, unsigned int tmp)
1514{
1515	i_mfc0(p, tmp, C0_INDEX);
1516	i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1517	il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1518	i_mfc0(p, tmp, C0_EPC); /* branch delay */
1519	i_tlbwi(p); /* cp0 delay */
1520	i_jr(p, tmp);
1521	i_rfe(p); /* branch delay */
1522	l_r3000_write_probe_fail(l, *p);
1523	i_tlbwr(p); /* cp0 delay */
1524	i_jr(p, tmp);
1525	i_rfe(p); /* branch delay */
1526}
1527
1528static void __init
1529build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1530				   unsigned int ptr)
1531{
1532	long pgdc = (long)pgd_current;
1533
1534	i_mfc0(p, pte, C0_BADVADDR);
1535	i_lui(p, ptr, rel_hi(pgdc)); /* cp0 delay */
1536	i_lw(p, ptr, rel_lo(pgdc), ptr);
1537	i_srl(p, pte, pte, 22); /* load delay */
1538	i_sll(p, pte, pte, 2);
1539	i_addu(p, ptr, ptr, pte);
1540	i_mfc0(p, pte, C0_CONTEXT);
1541	i_lw(p, ptr, 0, ptr); /* cp0 delay */
1542	i_andi(p, pte, pte, 0xffc); /* load delay */
1543	i_addu(p, ptr, ptr, pte);
1544	i_lw(p, pte, 0, ptr);
1545	i_tlbp(p); /* load delay */
1546}
1547
1548static void __init build_r3000_tlb_load_handler(void)
1549{
1550	u32 *p = handle_tlbl;
1551	struct label *l = labels;
1552	struct reloc *r = relocs;
1553	int i;
1554
1555	memset(handle_tlbl, 0, sizeof(handle_tlbl));
1556	memset(labels, 0, sizeof(labels));
1557	memset(relocs, 0, sizeof(relocs));
1558
1559	build_r3000_tlbchange_handler_head(&p, K0, K1);
1560	build_pte_present(&p, &l, &r, K0, K1, label_nopage_tlbl);
1561	i_nop(&p); /* load delay */
1562	build_make_valid(&p, &r, K0, K1);
1563	build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1564
1565	l_nopage_tlbl(&l, p);
1566	i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1567	i_nop(&p);
1568
1569	if ((p - handle_tlbl) > FASTPATH_SIZE)
1570		panic("TLB load handler fastpath space exceeded");
1571
1572	resolve_relocs(relocs, labels);
1573	pr_info("Synthesized TLB load handler fastpath (%u instructions).\n",
1574		(unsigned int)(p - handle_tlbl));
1575
1576	pr_debug("\t.set push\n");
1577	pr_debug("\t.set noreorder\n");
1578	for (i = 0; i < (p - handle_tlbl); i++)
1579		pr_debug("\t.word 0x%08x\n", handle_tlbl[i]);
1580	pr_debug("\t.set pop\n");
1581}
1582
1583static void __init build_r3000_tlb_store_handler(void)
1584{
1585	u32 *p = handle_tlbs;
1586	struct label *l = labels;
1587	struct reloc *r = relocs;
1588	int i;
1589
1590	memset(handle_tlbs, 0, sizeof(handle_tlbs));
1591	memset(labels, 0, sizeof(labels));
1592	memset(relocs, 0, sizeof(relocs));
1593
1594	build_r3000_tlbchange_handler_head(&p, K0, K1);
1595	build_pte_writable(&p, &l, &r, K0, K1, label_nopage_tlbs);
1596	i_nop(&p); /* load delay */
1597	build_make_write(&p, &r, K0, K1);
1598	build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1599
1600	l_nopage_tlbs(&l, p);
1601	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1602	i_nop(&p);
1603
1604	if ((p - handle_tlbs) > FASTPATH_SIZE)
1605		panic("TLB store handler fastpath space exceeded");
1606
1607	resolve_relocs(relocs, labels);
1608	pr_info("Synthesized TLB store handler fastpath (%u instructions).\n",
1609		(unsigned int)(p - handle_tlbs));
1610
1611	pr_debug("\t.set push\n");
1612	pr_debug("\t.set noreorder\n");
1613	for (i = 0; i < (p - handle_tlbs); i++)
1614		pr_debug("\t.word 0x%08x\n", handle_tlbs[i]);
1615	pr_debug("\t.set pop\n");
1616}
1617
1618static void __init build_r3000_tlb_modify_handler(void)
1619{
1620	u32 *p = handle_tlbm;
1621	struct label *l = labels;
1622	struct reloc *r = relocs;
1623	int i;
1624
1625	memset(handle_tlbm, 0, sizeof(handle_tlbm));
1626	memset(labels, 0, sizeof(labels));
1627	memset(relocs, 0, sizeof(relocs));
1628
1629	build_r3000_tlbchange_handler_head(&p, K0, K1);
1630	build_pte_modifiable(&p, &l, &r, K0, K1, label_nopage_tlbm);
1631	i_nop(&p); /* load delay */
1632	build_make_write(&p, &r, K0, K1);
1633	build_r3000_pte_reload_tlbwi(&p, K0, K1);
1634
1635	l_nopage_tlbm(&l, p);
1636	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1637	i_nop(&p);
1638
1639	if ((p - handle_tlbm) > FASTPATH_SIZE)
1640		panic("TLB modify handler fastpath space exceeded");
1641
1642	resolve_relocs(relocs, labels);
1643	pr_info("Synthesized TLB modify handler fastpath (%u instructions).\n",
1644		(unsigned int)(p - handle_tlbm));
1645
1646	pr_debug("\t.set push\n");
1647	pr_debug("\t.set noreorder\n");
1648	for (i = 0; i < (p - handle_tlbm); i++)
1649		pr_debug("\t.word 0x%08x\n", handle_tlbm[i]);
1650	pr_debug("\t.set pop\n");
1651}
1652
1653/*
1654 * R4000 style TLB load/store/modify handlers.
1655 */
1656static void __init
1657build_r4000_tlbchange_handler_head(u32 **p, struct label **l,
1658				   struct reloc **r, unsigned int pte,
1659				   unsigned int ptr)
1660{
1661#ifdef CONFIG_64BIT
1662	build_get_pmde64(p, l, r, pte, ptr); /* get pmd in ptr */
1663#else
1664	build_get_pgde32(p, pte, ptr); /* get pgd in ptr */
1665#endif
1666
1667	i_MFC0(p, pte, C0_BADVADDR);
1668	i_LW(p, ptr, 0, ptr);
1669	i_SRL(p, pte, pte, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
1670	i_andi(p, pte, pte, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
1671	i_ADDU(p, ptr, ptr, pte);
1672
1673#ifdef CONFIG_SMP
1674	l_smp_pgtable_change(l, *p);
1675# endif
1676	iPTE_LW(p, l, pte, ptr); /* get even pte */
1677	build_tlb_probe_entry(p);
1678}
1679
1680static void __init
1681build_r4000_tlbchange_handler_tail(u32 **p, struct label **l,
1682				   struct reloc **r, unsigned int tmp,
1683				   unsigned int ptr)
1684{
1685	i_ori(p, ptr, ptr, sizeof(pte_t));
1686	i_xori(p, ptr, ptr, sizeof(pte_t));
1687	build_update_entries(p, tmp, ptr);
1688	build_tlb_write_entry(p, l, r, tlb_indexed);
1689	l_leave(l, *p);
1690	i_eret(p); /* return from trap */
1691
1692#ifdef CONFIG_64BIT
1693	build_get_pgd_vmalloc64(p, l, r, tmp, ptr);
1694#endif
1695}
1696
1697static void __init build_r4000_tlb_load_handler(void)
1698{
1699	u32 *p = handle_tlbl;
1700	struct label *l = labels;
1701	struct reloc *r = relocs;
1702	int i;
1703
1704	memset(handle_tlbl, 0, sizeof(handle_tlbl));
1705	memset(labels, 0, sizeof(labels));
1706	memset(relocs, 0, sizeof(relocs));
1707
1708	if (bcm1250_m3_war()) {
1709		i_MFC0(&p, K0, C0_BADVADDR);
1710		i_MFC0(&p, K1, C0_ENTRYHI);
1711		i_xor(&p, K0, K0, K1);
1712		i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
1713		il_bnez(&p, &r, K0, label_leave);
1714		/* No need for i_nop */
1715	}
1716
1717	build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1718	build_pte_present(&p, &l, &r, K0, K1, label_nopage_tlbl);
1719	build_make_valid(&p, &r, K0, K1);
1720	build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1721
1722	l_nopage_tlbl(&l, p);
1723	i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1724	i_nop(&p);
1725
1726	if ((p - handle_tlbl) > FASTPATH_SIZE)
1727		panic("TLB load handler fastpath space exceeded");
1728
1729	resolve_relocs(relocs, labels);
1730	pr_info("Synthesized TLB load handler fastpath (%u instructions).\n",
1731		(unsigned int)(p - handle_tlbl));
1732
1733	pr_debug("\t.set push\n");
1734	pr_debug("\t.set noreorder\n");
1735	for (i = 0; i < (p - handle_tlbl); i++)
1736		pr_debug("\t.word 0x%08x\n", handle_tlbl[i]);
1737	pr_debug("\t.set pop\n");
1738}
1739
1740static void __init build_r4000_tlb_store_handler(void)
1741{
1742	u32 *p = handle_tlbs;
1743	struct label *l = labels;
1744	struct reloc *r = relocs;
1745	int i;
1746
1747	memset(handle_tlbs, 0, sizeof(handle_tlbs));
1748	memset(labels, 0, sizeof(labels));
1749	memset(relocs, 0, sizeof(relocs));
1750
1751	build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1752	build_pte_writable(&p, &l, &r, K0, K1, label_nopage_tlbs);
1753	build_make_write(&p, &r, K0, K1);
1754	build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1755
1756	l_nopage_tlbs(&l, p);
1757	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1758	i_nop(&p);
1759
1760	if ((p - handle_tlbs) > FASTPATH_SIZE)
1761		panic("TLB store handler fastpath space exceeded");
1762
1763	resolve_relocs(relocs, labels);
1764	pr_info("Synthesized TLB store handler fastpath (%u instructions).\n",
1765		(unsigned int)(p - handle_tlbs));
1766
1767	pr_debug("\t.set push\n");
1768	pr_debug("\t.set noreorder\n");
1769	for (i = 0; i < (p - handle_tlbs); i++)
1770		pr_debug("\t.word 0x%08x\n", handle_tlbs[i]);
1771	pr_debug("\t.set pop\n");
1772}
1773
1774static void __init build_r4000_tlb_modify_handler(void)
1775{
1776	u32 *p = handle_tlbm;
1777	struct label *l = labels;
1778	struct reloc *r = relocs;
1779	int i;
1780
1781	memset(handle_tlbm, 0, sizeof(handle_tlbm));
1782	memset(labels, 0, sizeof(labels));
1783	memset(relocs, 0, sizeof(relocs));
1784
1785	build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1786	build_pte_modifiable(&p, &l, &r, K0, K1, label_nopage_tlbm);
1787	/* Present and writable bits set, set accessed and dirty bits. */
1788	build_make_write(&p, &r, K0, K1);
1789	build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1790
1791	l_nopage_tlbm(&l, p);
1792	i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1793	i_nop(&p);
1794
1795	if ((p - handle_tlbm) > FASTPATH_SIZE)
1796		panic("TLB modify handler fastpath space exceeded");
1797
1798	resolve_relocs(relocs, labels);
1799	pr_info("Synthesized TLB modify handler fastpath (%u instructions).\n",
1800		(unsigned int)(p - handle_tlbm));
1801
1802	pr_debug("\t.set push\n");
1803	pr_debug("\t.set noreorder\n");
1804	for (i = 0; i < (p - handle_tlbm); i++)
1805		pr_debug("\t.word 0x%08x\n", handle_tlbm[i]);
1806	pr_debug("\t.set pop\n");
1807}
1808
1809void __init build_tlb_refill_handler(void)
1810{
1811	/*
1812	 * The refill handler is generated per-CPU, multi-node systems
1813	 * may have local storage for it. The other handlers are only
1814	 * needed once.
1815	 */
1816	static int run_once = 0;
1817
1818	switch (current_cpu_data.cputype) {
1819	case CPU_R2000:
1820	case CPU_R3000:
1821	case CPU_R3000A:
1822	case CPU_R3081E:
1823	case CPU_TX3912:
1824	case CPU_TX3922:
1825	case CPU_TX3927:
1826		build_r3000_tlb_refill_handler();
1827		if (!run_once) {
1828			build_r3000_tlb_load_handler();
1829			build_r3000_tlb_store_handler();
1830			build_r3000_tlb_modify_handler();
1831			run_once++;
1832		}
1833		break;
1834
1835	case CPU_R6000:
1836	case CPU_R6000A:
1837		panic("No R6000 TLB refill handler yet");
1838		break;
1839
1840	case CPU_R8000:
1841		panic("No R8000 TLB refill handler yet");
1842		break;
1843
1844	default:
1845		build_r4000_tlb_refill_handler();
1846		if (!run_once) {
1847			build_r4000_tlb_load_handler();
1848			build_r4000_tlb_store_handler();
1849			build_r4000_tlb_modify_handler();
1850			run_once++;
1851		}
1852	}
1853}
1854
1855void __init flush_tlb_handlers(void)
1856{
1857	flush_icache_range((unsigned long)handle_tlbl,
1858			   (unsigned long)handle_tlbl + sizeof(handle_tlbl));
1859	flush_icache_range((unsigned long)handle_tlbs,
1860			   (unsigned long)handle_tlbs + sizeof(handle_tlbs));
1861	flush_icache_range((unsigned long)handle_tlbm,
1862			   (unsigned long)handle_tlbm + sizeof(handle_tlbm));
1863}
1864