1 /*
2  * unaligned.c: Unaligned load/store trap handling with special
3  *              cases for the kernel to do them more quickly.
4  *
5  * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
6  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7  */
8 
9 
10 #include <linux/jiffies.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <linux/module.h>
15 #include <asm/asi.h>
16 #include <asm/ptrace.h>
17 #include <asm/pstate.h>
18 #include <asm/processor.h>
19 #include <asm/uaccess.h>
20 #include <linux/smp.h>
21 #include <linux/bitops.h>
22 #include <linux/perf_event.h>
23 #include <linux/ratelimit.h>
24 #include <linux/bitops.h>
25 #include <asm/fpumacro.h>
26 #include <asm/cacheflush.h>
27 
28 enum direction {
29 	load,    /* ld, ldd, ldh, ldsh */
30 	store,   /* st, std, sth, stsh */
31 	both,    /* Swap, ldstub, cas, ... */
32 	fpld,
33 	fpst,
34 	invalid,
35 };
36 
decode_direction(unsigned int insn)37 static inline enum direction decode_direction(unsigned int insn)
38 {
39 	unsigned long tmp = (insn >> 21) & 1;
40 
41 	if (!tmp)
42 		return load;
43 	else {
44 		switch ((insn>>19)&0xf) {
45 		case 15: /* swap* */
46 			return both;
47 		default:
48 			return store;
49 		}
50 	}
51 }
52 
53 /* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
decode_access_size(struct pt_regs * regs,unsigned int insn)54 static inline int decode_access_size(struct pt_regs *regs, unsigned int insn)
55 {
56 	unsigned int tmp;
57 
58 	tmp = ((insn >> 19) & 0xf);
59 	if (tmp == 11 || tmp == 14) /* ldx/stx */
60 		return 8;
61 	tmp &= 3;
62 	if (!tmp)
63 		return 4;
64 	else if (tmp == 3)
65 		return 16;	/* ldd/std - Although it is actually 8 */
66 	else if (tmp == 2)
67 		return 2;
68 	else {
69 		printk("Impossible unaligned trap. insn=%08x\n", insn);
70 		die_if_kernel("Byte sized unaligned access?!?!", regs);
71 
72 		/* GCC should never warn that control reaches the end
73 		 * of this function without returning a value because
74 		 * die_if_kernel() is marked with attribute 'noreturn'.
75 		 * Alas, some versions do...
76 		 */
77 
78 		return 0;
79 	}
80 }
81 
decode_asi(unsigned int insn,struct pt_regs * regs)82 static inline int decode_asi(unsigned int insn, struct pt_regs *regs)
83 {
84 	if (insn & 0x800000) {
85 		if (insn & 0x2000)
86 			return (unsigned char)(regs->tstate >> 24);	/* %asi */
87 		else
88 			return (unsigned char)(insn >> 5);		/* imm_asi */
89 	} else
90 		return ASI_P;
91 }
92 
93 /* 0x400000 = signed, 0 = unsigned */
decode_signedness(unsigned int insn)94 static inline int decode_signedness(unsigned int insn)
95 {
96 	return (insn & 0x400000);
97 }
98 
maybe_flush_windows(unsigned int rs1,unsigned int rs2,unsigned int rd,int from_kernel)99 static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
100 				       unsigned int rd, int from_kernel)
101 {
102 	if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
103 		if (from_kernel != 0)
104 			__asm__ __volatile__("flushw");
105 		else
106 			flushw_user();
107 	}
108 }
109 
sign_extend_imm13(long imm)110 static inline long sign_extend_imm13(long imm)
111 {
112 	return imm << 51 >> 51;
113 }
114 
fetch_reg(unsigned int reg,struct pt_regs * regs)115 static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
116 {
117 	unsigned long value;
118 
119 	if (reg < 16)
120 		return (!reg ? 0 : regs->u_regs[reg]);
121 	if (regs->tstate & TSTATE_PRIV) {
122 		struct reg_window *win;
123 		win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
124 		value = win->locals[reg - 16];
125 	} else if (test_thread_flag(TIF_32BIT)) {
126 		struct reg_window32 __user *win32;
127 		win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
128 		get_user(value, &win32->locals[reg - 16]);
129 	} else {
130 		struct reg_window __user *win;
131 		win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
132 		get_user(value, &win->locals[reg - 16]);
133 	}
134 	return value;
135 }
136 
fetch_reg_addr(unsigned int reg,struct pt_regs * regs)137 static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
138 {
139 	if (reg < 16)
140 		return &regs->u_regs[reg];
141 	if (regs->tstate & TSTATE_PRIV) {
142 		struct reg_window *win;
143 		win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
144 		return &win->locals[reg - 16];
145 	} else if (test_thread_flag(TIF_32BIT)) {
146 		struct reg_window32 *win32;
147 		win32 = (struct reg_window32 *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
148 		return (unsigned long *)&win32->locals[reg - 16];
149 	} else {
150 		struct reg_window *win;
151 		win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
152 		return &win->locals[reg - 16];
153 	}
154 }
155 
compute_effective_address(struct pt_regs * regs,unsigned int insn,unsigned int rd)156 unsigned long compute_effective_address(struct pt_regs *regs,
157 					unsigned int insn, unsigned int rd)
158 {
159 	unsigned int rs1 = (insn >> 14) & 0x1f;
160 	unsigned int rs2 = insn & 0x1f;
161 	int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
162 
163 	if (insn & 0x2000) {
164 		maybe_flush_windows(rs1, 0, rd, from_kernel);
165 		return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
166 	} else {
167 		maybe_flush_windows(rs1, rs2, rd, from_kernel);
168 		return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
169 	}
170 }
171 
172 /* This is just to make gcc think die_if_kernel does return... */
unaligned_panic(char * str,struct pt_regs * regs)173 static void __used unaligned_panic(char *str, struct pt_regs *regs)
174 {
175 	die_if_kernel(str, regs);
176 }
177 
178 extern int do_int_load(unsigned long *dest_reg, int size,
179 		       unsigned long *saddr, int is_signed, int asi);
180 
181 extern int __do_int_store(unsigned long *dst_addr, int size,
182 			  unsigned long src_val, int asi);
183 
do_int_store(int reg_num,int size,unsigned long * dst_addr,struct pt_regs * regs,int asi,int orig_asi)184 static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
185 			       struct pt_regs *regs, int asi, int orig_asi)
186 {
187 	unsigned long zero = 0;
188 	unsigned long *src_val_p = &zero;
189 	unsigned long src_val;
190 
191 	if (size == 16) {
192 		size = 8;
193 		zero = (((long)(reg_num ?
194 		        (unsigned)fetch_reg(reg_num, regs) : 0)) << 32) |
195 			(unsigned)fetch_reg(reg_num + 1, regs);
196 	} else if (reg_num) {
197 		src_val_p = fetch_reg_addr(reg_num, regs);
198 	}
199 	src_val = *src_val_p;
200 	if (unlikely(asi != orig_asi)) {
201 		switch (size) {
202 		case 2:
203 			src_val = swab16(src_val);
204 			break;
205 		case 4:
206 			src_val = swab32(src_val);
207 			break;
208 		case 8:
209 			src_val = swab64(src_val);
210 			break;
211 		case 16:
212 		default:
213 			BUG();
214 			break;
215 		}
216 	}
217 	return __do_int_store(dst_addr, size, src_val, asi);
218 }
219 
advance(struct pt_regs * regs)220 static inline void advance(struct pt_regs *regs)
221 {
222 	regs->tpc   = regs->tnpc;
223 	regs->tnpc += 4;
224 	if (test_thread_flag(TIF_32BIT)) {
225 		regs->tpc &= 0xffffffff;
226 		regs->tnpc &= 0xffffffff;
227 	}
228 }
229 
floating_point_load_or_store_p(unsigned int insn)230 static inline int floating_point_load_or_store_p(unsigned int insn)
231 {
232 	return (insn >> 24) & 1;
233 }
234 
ok_for_kernel(unsigned int insn)235 static inline int ok_for_kernel(unsigned int insn)
236 {
237 	return !floating_point_load_or_store_p(insn);
238 }
239 
kernel_mna_trap_fault(int fixup_tstate_asi)240 static void kernel_mna_trap_fault(int fixup_tstate_asi)
241 {
242 	struct pt_regs *regs = current_thread_info()->kern_una_regs;
243 	unsigned int insn = current_thread_info()->kern_una_insn;
244 	const struct exception_table_entry *entry;
245 
246 	entry = search_exception_tables(regs->tpc);
247 	if (!entry) {
248 		unsigned long address;
249 
250 		address = compute_effective_address(regs, insn,
251 						    ((insn >> 25) & 0x1f));
252         	if (address < PAGE_SIZE) {
253                 	printk(KERN_ALERT "Unable to handle kernel NULL "
254 			       "pointer dereference in mna handler");
255         	} else
256                 	printk(KERN_ALERT "Unable to handle kernel paging "
257 			       "request in mna handler");
258 	        printk(KERN_ALERT " at virtual address %016lx\n",address);
259 		printk(KERN_ALERT "current->{active_,}mm->context = %016lx\n",
260 			(current->mm ? CTX_HWBITS(current->mm->context) :
261 			CTX_HWBITS(current->active_mm->context)));
262 		printk(KERN_ALERT "current->{active_,}mm->pgd = %016lx\n",
263 			(current->mm ? (unsigned long) current->mm->pgd :
264 			(unsigned long) current->active_mm->pgd));
265 	        die_if_kernel("Oops", regs);
266 		/* Not reached */
267 	}
268 	regs->tpc = entry->fixup;
269 	regs->tnpc = regs->tpc + 4;
270 
271 	if (fixup_tstate_asi) {
272 		regs->tstate &= ~TSTATE_ASI;
273 		regs->tstate |= (ASI_AIUS << 24UL);
274 	}
275 }
276 
log_unaligned(struct pt_regs * regs)277 static void log_unaligned(struct pt_regs *regs)
278 {
279 	static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
280 
281 	if (__ratelimit(&ratelimit)) {
282 		printk("Kernel unaligned access at TPC[%lx] %pS\n",
283 		       regs->tpc, (void *) regs->tpc);
284 	}
285 }
286 
kernel_unaligned_trap(struct pt_regs * regs,unsigned int insn)287 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
288 {
289 	enum direction dir = decode_direction(insn);
290 	int size = decode_access_size(regs, insn);
291 	int orig_asi, asi;
292 
293 	current_thread_info()->kern_una_regs = regs;
294 	current_thread_info()->kern_una_insn = insn;
295 
296 	orig_asi = asi = decode_asi(insn, regs);
297 
298 	/* If this is a {get,put}_user() on an unaligned userspace pointer,
299 	 * just signal a fault and do not log the event.
300 	 */
301 	if (asi == ASI_AIUS) {
302 		kernel_mna_trap_fault(0);
303 		return;
304 	}
305 
306 	log_unaligned(regs);
307 
308 	if (!ok_for_kernel(insn) || dir == both) {
309 		printk("Unsupported unaligned load/store trap for kernel "
310 		       "at <%016lx>.\n", regs->tpc);
311 		unaligned_panic("Kernel does fpu/atomic "
312 				"unaligned load/store.", regs);
313 
314 		kernel_mna_trap_fault(0);
315 	} else {
316 		unsigned long addr, *reg_addr;
317 		int err;
318 
319 		addr = compute_effective_address(regs, insn,
320 						 ((insn >> 25) & 0x1f));
321 		perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
322 		switch (asi) {
323 		case ASI_NL:
324 		case ASI_AIUPL:
325 		case ASI_AIUSL:
326 		case ASI_PL:
327 		case ASI_SL:
328 		case ASI_PNFL:
329 		case ASI_SNFL:
330 			asi &= ~0x08;
331 			break;
332 		}
333 		switch (dir) {
334 		case load:
335 			reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
336 			err = do_int_load(reg_addr, size,
337 					  (unsigned long *) addr,
338 					  decode_signedness(insn), asi);
339 			if (likely(!err) && unlikely(asi != orig_asi)) {
340 				unsigned long val_in = *reg_addr;
341 				switch (size) {
342 				case 2:
343 					val_in = swab16(val_in);
344 					break;
345 				case 4:
346 					val_in = swab32(val_in);
347 					break;
348 				case 8:
349 					val_in = swab64(val_in);
350 					break;
351 				case 16:
352 				default:
353 					BUG();
354 					break;
355 				}
356 				*reg_addr = val_in;
357 			}
358 			break;
359 
360 		case store:
361 			err = do_int_store(((insn>>25)&0x1f), size,
362 					   (unsigned long *) addr, regs,
363 					   asi, orig_asi);
364 			break;
365 
366 		default:
367 			panic("Impossible kernel unaligned trap.");
368 			/* Not reached... */
369 		}
370 		if (unlikely(err))
371 			kernel_mna_trap_fault(1);
372 		else
373 			advance(regs);
374 	}
375 }
376 
handle_popc(u32 insn,struct pt_regs * regs)377 int handle_popc(u32 insn, struct pt_regs *regs)
378 {
379 	int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
380 	int ret, rd = ((insn >> 25) & 0x1f);
381 	u64 value;
382 
383 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
384 	if (insn & 0x2000) {
385 		maybe_flush_windows(0, 0, rd, from_kernel);
386 		value = sign_extend_imm13(insn);
387 	} else {
388 		maybe_flush_windows(0, insn & 0x1f, rd, from_kernel);
389 		value = fetch_reg(insn & 0x1f, regs);
390 	}
391 	ret = hweight64(value);
392 	if (rd < 16) {
393 		if (rd)
394 			regs->u_regs[rd] = ret;
395 	} else {
396 		if (test_thread_flag(TIF_32BIT)) {
397 			struct reg_window32 __user *win32;
398 			win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
399 			put_user(ret, &win32->locals[rd - 16]);
400 		} else {
401 			struct reg_window __user *win;
402 			win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
403 			put_user(ret, &win->locals[rd - 16]);
404 		}
405 	}
406 	advance(regs);
407 	return 1;
408 }
409 
410 extern void do_fpother(struct pt_regs *regs);
411 extern void do_privact(struct pt_regs *regs);
412 extern void spitfire_data_access_exception(struct pt_regs *regs,
413 					   unsigned long sfsr,
414 					   unsigned long sfar);
415 extern void sun4v_data_access_exception(struct pt_regs *regs,
416 					unsigned long addr,
417 					unsigned long type_ctx);
418 
handle_ldf_stq(u32 insn,struct pt_regs * regs)419 int handle_ldf_stq(u32 insn, struct pt_regs *regs)
420 {
421 	unsigned long addr = compute_effective_address(regs, insn, 0);
422 	int freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
423 	struct fpustate *f = FPUSTATE;
424 	int asi = decode_asi(insn, regs);
425 	int flag = (freg < 32) ? FPRS_DL : FPRS_DU;
426 
427 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
428 
429 	save_and_clear_fpu();
430 	current_thread_info()->xfsr[0] &= ~0x1c000;
431 	if (freg & 3) {
432 		current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
433 		do_fpother(regs);
434 		return 0;
435 	}
436 	if (insn & 0x200000) {
437 		/* STQ */
438 		u64 first = 0, second = 0;
439 
440 		if (current_thread_info()->fpsaved[0] & flag) {
441 			first = *(u64 *)&f->regs[freg];
442 			second = *(u64 *)&f->regs[freg+2];
443 		}
444 		if (asi < 0x80) {
445 			do_privact(regs);
446 			return 1;
447 		}
448 		switch (asi) {
449 		case ASI_P:
450 		case ASI_S: break;
451 		case ASI_PL:
452 		case ASI_SL:
453 			{
454 				/* Need to convert endians */
455 				u64 tmp = __swab64p(&first);
456 
457 				first = __swab64p(&second);
458 				second = tmp;
459 				break;
460 			}
461 		default:
462 			if (tlb_type == hypervisor)
463 				sun4v_data_access_exception(regs, addr, 0);
464 			else
465 				spitfire_data_access_exception(regs, 0, addr);
466 			return 1;
467 		}
468 		if (put_user (first >> 32, (u32 __user *)addr) ||
469 		    __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
470 		    __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
471 		    __put_user ((u32)second, (u32 __user *)(addr + 12))) {
472 			if (tlb_type == hypervisor)
473 				sun4v_data_access_exception(regs, addr, 0);
474 			else
475 				spitfire_data_access_exception(regs, 0, addr);
476 		    	return 1;
477 		}
478 	} else {
479 		/* LDF, LDDF, LDQF */
480 		u32 data[4] __attribute__ ((aligned(8)));
481 		int size, i;
482 		int err;
483 
484 		if (asi < 0x80) {
485 			do_privact(regs);
486 			return 1;
487 		} else if (asi > ASI_SNFL) {
488 			if (tlb_type == hypervisor)
489 				sun4v_data_access_exception(regs, addr, 0);
490 			else
491 				spitfire_data_access_exception(regs, 0, addr);
492 			return 1;
493 		}
494 		switch (insn & 0x180000) {
495 		case 0x000000: size = 1; break;
496 		case 0x100000: size = 4; break;
497 		default: size = 2; break;
498 		}
499 		for (i = 0; i < size; i++)
500 			data[i] = 0;
501 
502 		err = get_user (data[0], (u32 __user *) addr);
503 		if (!err) {
504 			for (i = 1; i < size; i++)
505 				err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
506 		}
507 		if (err && !(asi & 0x2 /* NF */)) {
508 			if (tlb_type == hypervisor)
509 				sun4v_data_access_exception(regs, addr, 0);
510 			else
511 				spitfire_data_access_exception(regs, 0, addr);
512 			return 1;
513 		}
514 		if (asi & 0x8) /* Little */ {
515 			u64 tmp;
516 
517 			switch (size) {
518 			case 1: data[0] = le32_to_cpup(data + 0); break;
519 			default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
520 				break;
521 			case 4: tmp = le64_to_cpup((u64 *)(data + 0));
522 				*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
523 				*(u64 *)(data + 2) = tmp;
524 				break;
525 			}
526 		}
527 		if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
528 			current_thread_info()->fpsaved[0] = FPRS_FEF;
529 			current_thread_info()->gsr[0] = 0;
530 		}
531 		if (!(current_thread_info()->fpsaved[0] & flag)) {
532 			if (freg < 32)
533 				memset(f->regs, 0, 32*sizeof(u32));
534 			else
535 				memset(f->regs+32, 0, 32*sizeof(u32));
536 		}
537 		memcpy(f->regs + freg, data, size * 4);
538 		current_thread_info()->fpsaved[0] |= flag;
539 	}
540 	advance(regs);
541 	return 1;
542 }
543 
handle_ld_nf(u32 insn,struct pt_regs * regs)544 void handle_ld_nf(u32 insn, struct pt_regs *regs)
545 {
546 	int rd = ((insn >> 25) & 0x1f);
547 	int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
548 	unsigned long *reg;
549 
550 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
551 
552 	maybe_flush_windows(0, 0, rd, from_kernel);
553 	reg = fetch_reg_addr(rd, regs);
554 	if (from_kernel || rd < 16) {
555 		reg[0] = 0;
556 		if ((insn & 0x780000) == 0x180000)
557 			reg[1] = 0;
558 	} else if (test_thread_flag(TIF_32BIT)) {
559 		put_user(0, (int __user *) reg);
560 		if ((insn & 0x780000) == 0x180000)
561 			put_user(0, ((int __user *) reg) + 1);
562 	} else {
563 		put_user(0, (unsigned long __user *) reg);
564 		if ((insn & 0x780000) == 0x180000)
565 			put_user(0, (unsigned long __user *) reg + 1);
566 	}
567 	advance(regs);
568 }
569 
handle_lddfmna(struct pt_regs * regs,unsigned long sfar,unsigned long sfsr)570 void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
571 {
572 	unsigned long pc = regs->tpc;
573 	unsigned long tstate = regs->tstate;
574 	u32 insn;
575 	u64 value;
576 	u8 freg;
577 	int flag;
578 	struct fpustate *f = FPUSTATE;
579 
580 	if (tstate & TSTATE_PRIV)
581 		die_if_kernel("lddfmna from kernel", regs);
582 	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
583 	if (test_thread_flag(TIF_32BIT))
584 		pc = (u32)pc;
585 	if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
586 		int asi = decode_asi(insn, regs);
587 		u32 first, second;
588 		int err;
589 
590 		if ((asi > ASI_SNFL) ||
591 		    (asi < ASI_P))
592 			goto daex;
593 		first = second = 0;
594 		err = get_user(first, (u32 __user *)sfar);
595 		if (!err)
596 			err = get_user(second, (u32 __user *)(sfar + 4));
597 		if (err) {
598 			if (!(asi & 0x2))
599 				goto daex;
600 			first = second = 0;
601 		}
602 		save_and_clear_fpu();
603 		freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
604 		value = (((u64)first) << 32) | second;
605 		if (asi & 0x8) /* Little */
606 			value = __swab64p(&value);
607 		flag = (freg < 32) ? FPRS_DL : FPRS_DU;
608 		if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
609 			current_thread_info()->fpsaved[0] = FPRS_FEF;
610 			current_thread_info()->gsr[0] = 0;
611 		}
612 		if (!(current_thread_info()->fpsaved[0] & flag)) {
613 			if (freg < 32)
614 				memset(f->regs, 0, 32*sizeof(u32));
615 			else
616 				memset(f->regs+32, 0, 32*sizeof(u32));
617 		}
618 		*(u64 *)(f->regs + freg) = value;
619 		current_thread_info()->fpsaved[0] |= flag;
620 	} else {
621 daex:
622 		if (tlb_type == hypervisor)
623 			sun4v_data_access_exception(regs, sfar, sfsr);
624 		else
625 			spitfire_data_access_exception(regs, sfsr, sfar);
626 		return;
627 	}
628 	advance(regs);
629 }
630 
handle_stdfmna(struct pt_regs * regs,unsigned long sfar,unsigned long sfsr)631 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
632 {
633 	unsigned long pc = regs->tpc;
634 	unsigned long tstate = regs->tstate;
635 	u32 insn;
636 	u64 value;
637 	u8 freg;
638 	int flag;
639 	struct fpustate *f = FPUSTATE;
640 
641 	if (tstate & TSTATE_PRIV)
642 		die_if_kernel("stdfmna from kernel", regs);
643 	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
644 	if (test_thread_flag(TIF_32BIT))
645 		pc = (u32)pc;
646 	if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
647 		int asi = decode_asi(insn, regs);
648 		freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
649 		value = 0;
650 		flag = (freg < 32) ? FPRS_DL : FPRS_DU;
651 		if ((asi > ASI_SNFL) ||
652 		    (asi < ASI_P))
653 			goto daex;
654 		save_and_clear_fpu();
655 		if (current_thread_info()->fpsaved[0] & flag)
656 			value = *(u64 *)&f->regs[freg];
657 		switch (asi) {
658 		case ASI_P:
659 		case ASI_S: break;
660 		case ASI_PL:
661 		case ASI_SL:
662 			value = __swab64p(&value); break;
663 		default: goto daex;
664 		}
665 		if (put_user (value >> 32, (u32 __user *) sfar) ||
666 		    __put_user ((u32)value, (u32 __user *)(sfar + 4)))
667 			goto daex;
668 	} else {
669 daex:
670 		if (tlb_type == hypervisor)
671 			sun4v_data_access_exception(regs, sfar, sfsr);
672 		else
673 			spitfire_data_access_exception(regs, sfsr, sfar);
674 		return;
675 	}
676 	advance(regs);
677 }
678