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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2020 Western Digital Corporation or its affiliates.
  4 */
  5#include <linux/kernel.h>
  6#include <linux/init.h>
  7#include <linux/mm.h>
  8#include <linux/module.h>
  9#include <linux/perf_event.h>
 10#include <linux/irq.h>
 11#include <linux/stringify.h>
 12
 13#include <asm/processor.h>
 14#include <asm/ptrace.h>
 15#include <asm/csr.h>
 16#include <asm/entry-common.h>
 17#include <asm/hwprobe.h>
 18#include <asm/cpufeature.h>
 19
 20#define INSN_MATCH_LB			0x3
 21#define INSN_MASK_LB			0x707f
 22#define INSN_MATCH_LH			0x1003
 23#define INSN_MASK_LH			0x707f
 24#define INSN_MATCH_LW			0x2003
 25#define INSN_MASK_LW			0x707f
 26#define INSN_MATCH_LD			0x3003
 27#define INSN_MASK_LD			0x707f
 28#define INSN_MATCH_LBU			0x4003
 29#define INSN_MASK_LBU			0x707f
 30#define INSN_MATCH_LHU			0x5003
 31#define INSN_MASK_LHU			0x707f
 32#define INSN_MATCH_LWU			0x6003
 33#define INSN_MASK_LWU			0x707f
 34#define INSN_MATCH_SB			0x23
 35#define INSN_MASK_SB			0x707f
 36#define INSN_MATCH_SH			0x1023
 37#define INSN_MASK_SH			0x707f
 38#define INSN_MATCH_SW			0x2023
 39#define INSN_MASK_SW			0x707f
 40#define INSN_MATCH_SD			0x3023
 41#define INSN_MASK_SD			0x707f
 42
 43#define INSN_MATCH_FLW			0x2007
 44#define INSN_MASK_FLW			0x707f
 45#define INSN_MATCH_FLD			0x3007
 46#define INSN_MASK_FLD			0x707f
 47#define INSN_MATCH_FLQ			0x4007
 48#define INSN_MASK_FLQ			0x707f
 49#define INSN_MATCH_FSW			0x2027
 50#define INSN_MASK_FSW			0x707f
 51#define INSN_MATCH_FSD			0x3027
 52#define INSN_MASK_FSD			0x707f
 53#define INSN_MATCH_FSQ			0x4027
 54#define INSN_MASK_FSQ			0x707f
 55
 56#define INSN_MATCH_C_LD			0x6000
 57#define INSN_MASK_C_LD			0xe003
 58#define INSN_MATCH_C_SD			0xe000
 59#define INSN_MASK_C_SD			0xe003
 60#define INSN_MATCH_C_LW			0x4000
 61#define INSN_MASK_C_LW			0xe003
 62#define INSN_MATCH_C_SW			0xc000
 63#define INSN_MASK_C_SW			0xe003
 64#define INSN_MATCH_C_LDSP		0x6002
 65#define INSN_MASK_C_LDSP		0xe003
 66#define INSN_MATCH_C_SDSP		0xe002
 67#define INSN_MASK_C_SDSP		0xe003
 68#define INSN_MATCH_C_LWSP		0x4002
 69#define INSN_MASK_C_LWSP		0xe003
 70#define INSN_MATCH_C_SWSP		0xc002
 71#define INSN_MASK_C_SWSP		0xe003
 72
 73#define INSN_MATCH_C_FLD		0x2000
 74#define INSN_MASK_C_FLD			0xe003
 75#define INSN_MATCH_C_FLW		0x6000
 76#define INSN_MASK_C_FLW			0xe003
 77#define INSN_MATCH_C_FSD		0xa000
 78#define INSN_MASK_C_FSD			0xe003
 79#define INSN_MATCH_C_FSW		0xe000
 80#define INSN_MASK_C_FSW			0xe003
 81#define INSN_MATCH_C_FLDSP		0x2002
 82#define INSN_MASK_C_FLDSP		0xe003
 83#define INSN_MATCH_C_FSDSP		0xa002
 84#define INSN_MASK_C_FSDSP		0xe003
 85#define INSN_MATCH_C_FLWSP		0x6002
 86#define INSN_MASK_C_FLWSP		0xe003
 87#define INSN_MATCH_C_FSWSP		0xe002
 88#define INSN_MASK_C_FSWSP		0xe003
 89
 90#define INSN_LEN(insn)			((((insn) & 0x3) < 0x3) ? 2 : 4)
 91
 92#if defined(CONFIG_64BIT)
 93#define LOG_REGBYTES			3
 94#define XLEN				64
 95#else
 96#define LOG_REGBYTES			2
 97#define XLEN				32
 98#endif
 99#define REGBYTES			(1 << LOG_REGBYTES)
100#define XLEN_MINUS_16			((XLEN) - 16)
101
102#define SH_RD				7
103#define SH_RS1				15
104#define SH_RS2				20
105#define SH_RS2C				2
106
107#define RV_X(x, s, n)			(((x) >> (s)) & ((1 << (n)) - 1))
108#define RVC_LW_IMM(x)			((RV_X(x, 6, 1) << 2) | \
109					 (RV_X(x, 10, 3) << 3) | \
110					 (RV_X(x, 5, 1) << 6))
111#define RVC_LD_IMM(x)			((RV_X(x, 10, 3) << 3) | \
112					 (RV_X(x, 5, 2) << 6))
113#define RVC_LWSP_IMM(x)			((RV_X(x, 4, 3) << 2) | \
114					 (RV_X(x, 12, 1) << 5) | \
115					 (RV_X(x, 2, 2) << 6))
116#define RVC_LDSP_IMM(x)			((RV_X(x, 5, 2) << 3) | \
117					 (RV_X(x, 12, 1) << 5) | \
118					 (RV_X(x, 2, 3) << 6))
119#define RVC_SWSP_IMM(x)			((RV_X(x, 9, 4) << 2) | \
120					 (RV_X(x, 7, 2) << 6))
121#define RVC_SDSP_IMM(x)			((RV_X(x, 10, 3) << 3) | \
122					 (RV_X(x, 7, 3) << 6))
123#define RVC_RS1S(insn)			(8 + RV_X(insn, SH_RD, 3))
124#define RVC_RS2S(insn)			(8 + RV_X(insn, SH_RS2C, 3))
125#define RVC_RS2(insn)			RV_X(insn, SH_RS2C, 5)
126
127#define SHIFT_RIGHT(x, y)		\
128	((y) < 0 ? ((x) << -(y)) : ((x) >> (y)))
129
130#define REG_MASK			\
131	((1 << (5 + LOG_REGBYTES)) - (1 << LOG_REGBYTES))
132
133#define REG_OFFSET(insn, pos)		\
134	(SHIFT_RIGHT((insn), (pos) - LOG_REGBYTES) & REG_MASK)
135
136#define REG_PTR(insn, pos, regs)	\
137	(ulong *)((ulong)(regs) + REG_OFFSET(insn, pos))
138
139#define GET_RM(insn)			(((insn) >> 12) & 7)
140
141#define GET_RS1(insn, regs)		(*REG_PTR(insn, SH_RS1, regs))
142#define GET_RS2(insn, regs)		(*REG_PTR(insn, SH_RS2, regs))
143#define GET_RS1S(insn, regs)		(*REG_PTR(RVC_RS1S(insn), 0, regs))
144#define GET_RS2S(insn, regs)		(*REG_PTR(RVC_RS2S(insn), 0, regs))
145#define GET_RS2C(insn, regs)		(*REG_PTR(insn, SH_RS2C, regs))
146#define GET_SP(regs)			(*REG_PTR(2, 0, regs))
147#define SET_RD(insn, regs, val)		(*REG_PTR(insn, SH_RD, regs) = (val))
148#define IMM_I(insn)			((s32)(insn) >> 20)
149#define IMM_S(insn)			(((s32)(insn) >> 25 << 5) | \
150					 (s32)(((insn) >> 7) & 0x1f))
151#define MASK_FUNCT3			0x7000
152
153#define GET_PRECISION(insn) (((insn) >> 25) & 3)
154#define GET_RM(insn) (((insn) >> 12) & 7)
155#define PRECISION_S 0
156#define PRECISION_D 1
157
158#ifdef CONFIG_FPU
159
160#define FP_GET_RD(insn)		(insn >> 7 & 0x1F)
161
162extern void put_f32_reg(unsigned long fp_reg, unsigned long value);
163
164static int set_f32_rd(unsigned long insn, struct pt_regs *regs,
165		      unsigned long val)
166{
167	unsigned long fp_reg = FP_GET_RD(insn);
168
169	put_f32_reg(fp_reg, val);
170	regs->status |= SR_FS_DIRTY;
171
172	return 0;
173}
174
175extern void put_f64_reg(unsigned long fp_reg, unsigned long value);
176
177static int set_f64_rd(unsigned long insn, struct pt_regs *regs, u64 val)
178{
179	unsigned long fp_reg = FP_GET_RD(insn);
180	unsigned long value;
181
182#if __riscv_xlen == 32
183	value = (unsigned long) &val;
184#else
185	value = val;
186#endif
187	put_f64_reg(fp_reg, value);
188	regs->status |= SR_FS_DIRTY;
189
190	return 0;
191}
192
193#if __riscv_xlen == 32
194extern void get_f64_reg(unsigned long fp_reg, u64 *value);
195
196static u64 get_f64_rs(unsigned long insn, u8 fp_reg_offset,
197		      struct pt_regs *regs)
198{
199	unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F;
200	u64 val;
201
202	get_f64_reg(fp_reg, &val);
203	regs->status |= SR_FS_DIRTY;
204
205	return val;
206}
207#else
208
209extern unsigned long get_f64_reg(unsigned long fp_reg);
210
211static unsigned long get_f64_rs(unsigned long insn, u8 fp_reg_offset,
212				struct pt_regs *regs)
213{
214	unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F;
215	unsigned long val;
216
217	val = get_f64_reg(fp_reg);
218	regs->status |= SR_FS_DIRTY;
219
220	return val;
221}
222
223#endif
224
225extern unsigned long get_f32_reg(unsigned long fp_reg);
226
227static unsigned long get_f32_rs(unsigned long insn, u8 fp_reg_offset,
228				struct pt_regs *regs)
229{
230	unsigned long fp_reg = (insn >> fp_reg_offset) & 0x1F;
231	unsigned long val;
232
233	val = get_f32_reg(fp_reg);
234	regs->status |= SR_FS_DIRTY;
235
236	return val;
237}
238
239#else /* CONFIG_FPU */
240static void set_f32_rd(unsigned long insn, struct pt_regs *regs,
241		       unsigned long val) {}
242
243static void set_f64_rd(unsigned long insn, struct pt_regs *regs, u64 val) {}
244
245static unsigned long get_f64_rs(unsigned long insn, u8 fp_reg_offset,
246				struct pt_regs *regs)
247{
248	return 0;
249}
250
251static unsigned long get_f32_rs(unsigned long insn, u8 fp_reg_offset,
252				struct pt_regs *regs)
253{
254	return 0;
255}
256
257#endif
258
259#define GET_F64_RS2(insn, regs) (get_f64_rs(insn, 20, regs))
260#define GET_F64_RS2C(insn, regs) (get_f64_rs(insn, 2, regs))
261#define GET_F64_RS2S(insn, regs) (get_f64_rs(RVC_RS2S(insn), 0, regs))
262
263#define GET_F32_RS2(insn, regs) (get_f32_rs(insn, 20, regs))
264#define GET_F32_RS2C(insn, regs) (get_f32_rs(insn, 2, regs))
265#define GET_F32_RS2S(insn, regs) (get_f32_rs(RVC_RS2S(insn), 0, regs))
266
267#ifdef CONFIG_RISCV_M_MODE
268static inline int load_u8(struct pt_regs *regs, const u8 *addr, u8 *r_val)
269{
270	u8 val;
271
272	asm volatile("lbu %0, %1" : "=&r" (val) : "m" (*addr));
273	*r_val = val;
274
275	return 0;
276}
277
278static inline int store_u8(struct pt_regs *regs, u8 *addr, u8 val)
279{
280	asm volatile ("sb %0, %1\n" : : "r" (val), "m" (*addr));
281
282	return 0;
283}
284
285static inline int get_insn(struct pt_regs *regs, ulong mepc, ulong *r_insn)
286{
287	register ulong __mepc asm ("a2") = mepc;
288	ulong val, rvc_mask = 3, tmp;
289
290	asm ("and %[tmp], %[addr], 2\n"
291		"bnez %[tmp], 1f\n"
292#if defined(CONFIG_64BIT)
293		__stringify(LWU) " %[insn], (%[addr])\n"
294#else
295		__stringify(LW) " %[insn], (%[addr])\n"
296#endif
297		"and %[tmp], %[insn], %[rvc_mask]\n"
298		"beq %[tmp], %[rvc_mask], 2f\n"
299		"sll %[insn], %[insn], %[xlen_minus_16]\n"
300		"srl %[insn], %[insn], %[xlen_minus_16]\n"
301		"j 2f\n"
302		"1:\n"
303		"lhu %[insn], (%[addr])\n"
304		"and %[tmp], %[insn], %[rvc_mask]\n"
305		"bne %[tmp], %[rvc_mask], 2f\n"
306		"lhu %[tmp], 2(%[addr])\n"
307		"sll %[tmp], %[tmp], 16\n"
308		"add %[insn], %[insn], %[tmp]\n"
309		"2:"
310	: [insn] "=&r" (val), [tmp] "=&r" (tmp)
311	: [addr] "r" (__mepc), [rvc_mask] "r" (rvc_mask),
312	  [xlen_minus_16] "i" (XLEN_MINUS_16));
313
314	*r_insn = val;
315
316	return 0;
317}
318#else
319static inline int load_u8(struct pt_regs *regs, const u8 *addr, u8 *r_val)
320{
321	if (user_mode(regs)) {
322		return __get_user(*r_val, (u8 __user *)addr);
323	} else {
324		*r_val = *addr;
325		return 0;
326	}
327}
328
329static inline int store_u8(struct pt_regs *regs, u8 *addr, u8 val)
330{
331	if (user_mode(regs)) {
332		return __put_user(val, (u8 __user *)addr);
333	} else {
334		*addr = val;
335		return 0;
336	}
337}
338
339#define __read_insn(regs, insn, insn_addr)		\
340({							\
341	int __ret;					\
342							\
343	if (user_mode(regs)) {				\
344		__ret = __get_user(insn, insn_addr);	\
345	} else {					\
346		insn = *(__force u16 *)insn_addr;	\
347		__ret = 0;				\
348	}						\
349							\
350	__ret;						\
351})
352
353static inline int get_insn(struct pt_regs *regs, ulong epc, ulong *r_insn)
354{
355	ulong insn = 0;
356
357	if (epc & 0x2) {
358		ulong tmp = 0;
359		u16 __user *insn_addr = (u16 __user *)epc;
360
361		if (__read_insn(regs, insn, insn_addr))
362			return -EFAULT;
363		/* __get_user() uses regular "lw" which sign extend the loaded
364		 * value make sure to clear higher order bits in case we "or" it
365		 * below with the upper 16 bits half.
366		 */
367		insn &= GENMASK(15, 0);
368		if ((insn & __INSN_LENGTH_MASK) != __INSN_LENGTH_32) {
369			*r_insn = insn;
370			return 0;
371		}
372		insn_addr++;
373		if (__read_insn(regs, tmp, insn_addr))
374			return -EFAULT;
375		*r_insn = (tmp << 16) | insn;
376
377		return 0;
378	} else {
379		u32 __user *insn_addr = (u32 __user *)epc;
380
381		if (__read_insn(regs, insn, insn_addr))
382			return -EFAULT;
383		if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) {
384			*r_insn = insn;
385			return 0;
386		}
387		insn &= GENMASK(15, 0);
388		*r_insn = insn;
389
390		return 0;
391	}
392}
393#endif
394
395union reg_data {
396	u8 data_bytes[8];
397	ulong data_ulong;
398	u64 data_u64;
399};
400
401static bool unaligned_ctl __read_mostly;
402
403/* sysctl hooks */
404int unaligned_enabled __read_mostly = 1;	/* Enabled by default */
405
406int handle_misaligned_load(struct pt_regs *regs)
407{
408	union reg_data val;
409	unsigned long epc = regs->epc;
410	unsigned long insn;
411	unsigned long addr = regs->badaddr;
412	int i, fp = 0, shift = 0, len = 0;
413
414	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
415
416	*this_cpu_ptr(&misaligned_access_speed) = RISCV_HWPROBE_MISALIGNED_EMULATED;
417
418	if (!unaligned_enabled)
419		return -1;
420
421	if (user_mode(regs) && (current->thread.align_ctl & PR_UNALIGN_SIGBUS))
422		return -1;
423
424	if (get_insn(regs, epc, &insn))
425		return -1;
426
427	regs->epc = 0;
428
429	if ((insn & INSN_MASK_LW) == INSN_MATCH_LW) {
430		len = 4;
431		shift = 8 * (sizeof(unsigned long) - len);
432#if defined(CONFIG_64BIT)
433	} else if ((insn & INSN_MASK_LD) == INSN_MATCH_LD) {
434		len = 8;
435		shift = 8 * (sizeof(unsigned long) - len);
436	} else if ((insn & INSN_MASK_LWU) == INSN_MATCH_LWU) {
437		len = 4;
438#endif
439	} else if ((insn & INSN_MASK_FLD) == INSN_MATCH_FLD) {
440		fp = 1;
441		len = 8;
442	} else if ((insn & INSN_MASK_FLW) == INSN_MATCH_FLW) {
443		fp = 1;
444		len = 4;
445	} else if ((insn & INSN_MASK_LH) == INSN_MATCH_LH) {
446		len = 2;
447		shift = 8 * (sizeof(unsigned long) - len);
448	} else if ((insn & INSN_MASK_LHU) == INSN_MATCH_LHU) {
449		len = 2;
450#if defined(CONFIG_64BIT)
451	} else if ((insn & INSN_MASK_C_LD) == INSN_MATCH_C_LD) {
452		len = 8;
453		shift = 8 * (sizeof(unsigned long) - len);
454		insn = RVC_RS2S(insn) << SH_RD;
455	} else if ((insn & INSN_MASK_C_LDSP) == INSN_MATCH_C_LDSP &&
456		   ((insn >> SH_RD) & 0x1f)) {
457		len = 8;
458		shift = 8 * (sizeof(unsigned long) - len);
459#endif
460	} else if ((insn & INSN_MASK_C_LW) == INSN_MATCH_C_LW) {
461		len = 4;
462		shift = 8 * (sizeof(unsigned long) - len);
463		insn = RVC_RS2S(insn) << SH_RD;
464	} else if ((insn & INSN_MASK_C_LWSP) == INSN_MATCH_C_LWSP &&
465		   ((insn >> SH_RD) & 0x1f)) {
466		len = 4;
467		shift = 8 * (sizeof(unsigned long) - len);
468	} else if ((insn & INSN_MASK_C_FLD) == INSN_MATCH_C_FLD) {
469		fp = 1;
470		len = 8;
471		insn = RVC_RS2S(insn) << SH_RD;
472	} else if ((insn & INSN_MASK_C_FLDSP) == INSN_MATCH_C_FLDSP) {
473		fp = 1;
474		len = 8;
475#if defined(CONFIG_32BIT)
476	} else if ((insn & INSN_MASK_C_FLW) == INSN_MATCH_C_FLW) {
477		fp = 1;
478		len = 4;
479		insn = RVC_RS2S(insn) << SH_RD;
480	} else if ((insn & INSN_MASK_C_FLWSP) == INSN_MATCH_C_FLWSP) {
481		fp = 1;
482		len = 4;
483#endif
484	} else {
485		regs->epc = epc;
486		return -1;
487	}
488
489	if (!IS_ENABLED(CONFIG_FPU) && fp)
490		return -EOPNOTSUPP;
491
492	val.data_u64 = 0;
493	for (i = 0; i < len; i++) {
494		if (load_u8(regs, (void *)(addr + i), &val.data_bytes[i]))
495			return -1;
496	}
497
498	if (!fp)
499		SET_RD(insn, regs, val.data_ulong << shift >> shift);
500	else if (len == 8)
501		set_f64_rd(insn, regs, val.data_u64);
502	else
503		set_f32_rd(insn, regs, val.data_ulong);
504
505	regs->epc = epc + INSN_LEN(insn);
506
507	return 0;
508}
509
510int handle_misaligned_store(struct pt_regs *regs)
511{
512	union reg_data val;
513	unsigned long epc = regs->epc;
514	unsigned long insn;
515	unsigned long addr = regs->badaddr;
516	int i, len = 0, fp = 0;
517
518	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
519
520	if (!unaligned_enabled)
521		return -1;
522
523	if (user_mode(regs) && (current->thread.align_ctl & PR_UNALIGN_SIGBUS))
524		return -1;
525
526	if (get_insn(regs, epc, &insn))
527		return -1;
528
529	regs->epc = 0;
530
531	val.data_ulong = GET_RS2(insn, regs);
532
533	if ((insn & INSN_MASK_SW) == INSN_MATCH_SW) {
534		len = 4;
535#if defined(CONFIG_64BIT)
536	} else if ((insn & INSN_MASK_SD) == INSN_MATCH_SD) {
537		len = 8;
538#endif
539	} else if ((insn & INSN_MASK_FSD) == INSN_MATCH_FSD) {
540		fp = 1;
541		len = 8;
542		val.data_u64 = GET_F64_RS2(insn, regs);
543	} else if ((insn & INSN_MASK_FSW) == INSN_MATCH_FSW) {
544		fp = 1;
545		len = 4;
546		val.data_ulong = GET_F32_RS2(insn, regs);
547	} else if ((insn & INSN_MASK_SH) == INSN_MATCH_SH) {
548		len = 2;
549#if defined(CONFIG_64BIT)
550	} else if ((insn & INSN_MASK_C_SD) == INSN_MATCH_C_SD) {
551		len = 8;
552		val.data_ulong = GET_RS2S(insn, regs);
553	} else if ((insn & INSN_MASK_C_SDSP) == INSN_MATCH_C_SDSP) {
554		len = 8;
555		val.data_ulong = GET_RS2C(insn, regs);
556#endif
557	} else if ((insn & INSN_MASK_C_SW) == INSN_MATCH_C_SW) {
558		len = 4;
559		val.data_ulong = GET_RS2S(insn, regs);
560	} else if ((insn & INSN_MASK_C_SWSP) == INSN_MATCH_C_SWSP) {
561		len = 4;
562		val.data_ulong = GET_RS2C(insn, regs);
563	} else if ((insn & INSN_MASK_C_FSD) == INSN_MATCH_C_FSD) {
564		fp = 1;
565		len = 8;
566		val.data_u64 = GET_F64_RS2S(insn, regs);
567	} else if ((insn & INSN_MASK_C_FSDSP) == INSN_MATCH_C_FSDSP) {
568		fp = 1;
569		len = 8;
570		val.data_u64 = GET_F64_RS2C(insn, regs);
571#if !defined(CONFIG_64BIT)
572	} else if ((insn & INSN_MASK_C_FSW) == INSN_MATCH_C_FSW) {
573		fp = 1;
574		len = 4;
575		val.data_ulong = GET_F32_RS2S(insn, regs);
576	} else if ((insn & INSN_MASK_C_FSWSP) == INSN_MATCH_C_FSWSP) {
577		fp = 1;
578		len = 4;
579		val.data_ulong = GET_F32_RS2C(insn, regs);
580#endif
581	} else {
582		regs->epc = epc;
583		return -1;
584	}
585
586	if (!IS_ENABLED(CONFIG_FPU) && fp)
587		return -EOPNOTSUPP;
588
589	for (i = 0; i < len; i++) {
590		if (store_u8(regs, (void *)(addr + i), val.data_bytes[i]))
591			return -1;
592	}
593
594	regs->epc = epc + INSN_LEN(insn);
595
596	return 0;
597}
598
599bool check_unaligned_access_emulated(int cpu)
600{
601	long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu);
602	unsigned long tmp_var, tmp_val;
603	bool misaligned_emu_detected;
604
605	*mas_ptr = RISCV_HWPROBE_MISALIGNED_UNKNOWN;
606
607	__asm__ __volatile__ (
608		"       "REG_L" %[tmp], 1(%[ptr])\n"
609		: [tmp] "=r" (tmp_val) : [ptr] "r" (&tmp_var) : "memory");
610
611	misaligned_emu_detected = (*mas_ptr == RISCV_HWPROBE_MISALIGNED_EMULATED);
612	/*
613	 * If unaligned_ctl is already set, this means that we detected that all
614	 * CPUS uses emulated misaligned access at boot time. If that changed
615	 * when hotplugging the new cpu, this is something we don't handle.
616	 */
617	if (unlikely(unaligned_ctl && !misaligned_emu_detected)) {
618		pr_crit("CPU misaligned accesses non homogeneous (expected all emulated)\n");
619		while (true)
620			cpu_relax();
621	}
622
623	return misaligned_emu_detected;
624}
625
626void unaligned_emulation_finish(void)
627{
628	int cpu;
629
630	/*
631	 * We can only support PR_UNALIGN controls if all CPUs have misaligned
632	 * accesses emulated since tasks requesting such control can run on any
633	 * CPU.
634	 */
635	for_each_present_cpu(cpu) {
636		if (per_cpu(misaligned_access_speed, cpu) !=
637					RISCV_HWPROBE_MISALIGNED_EMULATED) {
638			return;
639		}
640	}
641	unaligned_ctl = true;
642}
643
644bool unaligned_ctl_available(void)
645{
646	return unaligned_ctl;
647}