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/usr/src/linux-headers-5.15.0-190/arch/openrisc/include/asm/

/usr/src/linux-headers-5.15.0-190/arch/openrisc/include/asm

Name	Size	Mode	Actions
bitops/	-	0755	rm
asm-offsets.h	35	0644	edit dl rm
atomic.h	3609	0644	edit dl rm
barrier.h	241	0644	edit dl rm
bitops.h	1326	0644	edit dl rm
cache.h	681	0644	edit dl rm
cacheflush.h	2204	0644	edit dl rm
cmpxchg.h	4056	0644	edit dl rm
cpuinfo.h	763	0644	edit dl rm
delay.h	463	0644	edit dl rm
elf.h	1860	0644	edit dl rm
fixmap.h	2596	0644	edit dl rm
futex.h	2293	0644	edit dl rm
io.h	833	0644	edit dl rm
irq.h	561	0644	edit dl rm
irqflags.h	659	0644	edit dl rm
Kbuild	238	0644	edit dl rm
linkage.h	557	0644	edit dl rm
mmu.h	521	0644	edit dl rm
mmu_context.h	1108	0644	edit dl rm
page.h	2288	0644	edit dl rm
pgalloc.h	1831	0644	edit dl rm
pgtable.h	12749	0644	edit dl rm
processor.h	2339	0644	edit dl rm
ptrace.h	3201	0644	edit dl rm
serial.h	928	0644	edit dl rm
setup.h	293	0644	edit dl rm
smp.h	822	0644	edit dl rm
spinlock.h	778	0644	edit dl rm
spinlock_types.h	188	0644	edit dl rm
spr.h	991	0644	edit dl rm
spr_defs.h	23252	0644	edit dl rm
string.h	324	0644	edit dl rm
syscall.h	1658	0644	edit dl rm
syscalls.h	969	0644	edit dl rm
thread_info.h	3787	0644	edit dl rm
time.h	627	0644	edit dl rm
timex.h	707	0644	edit dl rm
tlb.h	651	0644	edit dl rm
tlbflush.h	1844	0644	edit dl rm
uaccess.h	7985	0644	edit dl rm
unwinder.h	557	0644	edit dl rm
vmalloc.h	102	0644	edit dl rm

Edit: /usr/src/linux-headers-5.15.0-190/arch/openrisc/include/asm/cmpxchg.h (4056B)

/*
 * 1,2 and 4 byte cmpxchg and xchg implementations for OpenRISC.
 *
 * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
 * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 *
 * Note:
 * The portable implementations of 1 and 2 byte xchg and cmpxchg using a 4
 * byte cmpxchg is sourced heavily from the sh and mips implementations.
 */

#ifndef __ASM_OPENRISC_CMPXCHG_H
#define __ASM_OPENRISC_CMPXCHG_H

#include  <linux/bits.h>
#include  <linux/compiler.h>
#include  <linux/types.h>

#define __HAVE_ARCH_CMPXCHG 1

static inline unsigned long cmpxchg_u32(volatile void *ptr,
		unsigned long old, unsigned long new)
{
	__asm__ __volatile__(
		"1:	l.lwa %0, 0(%1)		\n"
		"	l.sfeq %0, %2		\n"
		"	l.bnf 2f		\n"
		"	 l.nop			\n"
		"	l.swa 0(%1), %3		\n"
		"	l.bnf 1b		\n"
		"	 l.nop			\n"
		"2:				\n"
		: "=&r"(old)
		: "r"(ptr), "r"(old), "r"(new)
		: "cc", "memory");

return old;
}

static inline unsigned long xchg_u32(volatile void *ptr,
		unsigned long val)
{
	__asm__ __volatile__(
		"1:	l.lwa %0, 0(%1)		\n"
		"	l.swa 0(%1), %2		\n"
		"	l.bnf 1b		\n"
		"	 l.nop			\n"
		: "=&r"(val)
		: "r"(ptr), "r"(val)
		: "cc", "memory");

return val;
}

static inline u32 cmpxchg_small(volatile void *ptr, u32 old, u32 new,
				int size)
{
	int off = (unsigned long)ptr % sizeof(u32);
	volatile u32 *p = ptr - off;
#ifdef __BIG_ENDIAN
	int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
#else
	int bitoff = off * BITS_PER_BYTE;
#endif
	u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff;
	u32 load32, old32, new32;
	u32 ret;

load32 = READ_ONCE(*p);

while (true) {
		ret = (load32 & bitmask) >> bitoff;
		if (old != ret)
			return ret;

old32 = (load32 & ~bitmask) | (old << bitoff);
		new32 = (load32 & ~bitmask) | (new << bitoff);

/* Do 32 bit cmpxchg */
		load32 = cmpxchg_u32(p, old32, new32);
		if (load32 == old32)
			return old;
	}
}

/* xchg */

static inline u32 xchg_small(volatile void *ptr, u32 x, int size)
{
	int off = (unsigned long)ptr % sizeof(u32);
	volatile u32 *p = ptr - off;
#ifdef __BIG_ENDIAN
	int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
#else
	int bitoff = off * BITS_PER_BYTE;
#endif
	u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff;
	u32 oldv, newv;
	u32 ret;

do {
		oldv = READ_ONCE(*p);
		ret = (oldv & bitmask) >> bitoff;
		newv = (oldv & ~bitmask) | (x << bitoff);
	} while (cmpxchg_u32(p, oldv, newv) != oldv);

return ret;
}

/*
 * This function doesn't exist, so you'll get a linker error
 * if something tries to do an invalid cmpxchg().
 */
extern unsigned long __cmpxchg_called_with_bad_pointer(void)
	__compiletime_error("Bad argument size for cmpxchg");

static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
		unsigned long new, int size)
{
	switch (size) {
	case 1:
	case 2:
		return cmpxchg_small(ptr, old, new, size);
	case 4:
		return cmpxchg_u32(ptr, old, new);
	default:
		return __cmpxchg_called_with_bad_pointer();
	}
}

#define arch_cmpxchg(ptr, o, n)						\
	({								\
		(__typeof__(*(ptr))) __cmpxchg((ptr),			\
					       (unsigned long)(o),	\
					       (unsigned long)(n),	\
					       sizeof(*(ptr)));		\
	})

/*
 * This function doesn't exist, so you'll get a linker error if
 * something tries to do an invalidly-sized xchg().
 */
extern unsigned long __xchg_called_with_bad_pointer(void)
	__compiletime_error("Bad argument size for xchg");

static inline unsigned long __xchg(volatile void *ptr, unsigned long with,
		int size)
{
	switch (size) {
	case 1:
	case 2:
		return xchg_small(ptr, with, size);
	case 4:
		return xchg_u32(ptr, with);
	default:
		return __xchg_called_with_bad_pointer();
	}
}

#define arch_xchg(ptr, with) 						\
	({								\
		(__typeof__(*(ptr))) __xchg((ptr),			\
					    (unsigned long)(with),	\
					    sizeof(*(ptr)));		\
	})

#endif /* __ASM_OPENRISC_CMPXCHG_H */

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