Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 219 insertions, 0 deletions

diff --git a/arch/loongarch/include/asm/cmpxchg.h b/arch/loongarch/include/asm/cmpxchg.h
new file mode 100644
index 000000000..ecfa6cf79
--- /dev/null
+++ b/arch/loongarch/include/asm/cmpxchg.h
@@ -0,0 +1,219 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_CMPXCHG_H
+#define __ASM_CMPXCHG_H
+
+#include <linux/bits.h>
+#include <linux/build_bug.h>
+#include <asm/barrier.h>
+
+#define __xchg_asm(amswap_db, m, val)		\
+({						\
+		__typeof(val) __ret;		\
+						\
+		__asm__ __volatile__ (		\
+		" "amswap_db" %1, %z2, %0 \n"	\
+		: "+ZB" (*m), "=&r" (__ret)	\
+		: "Jr" (val)			\
+		: "memory");			\
+						\
+		__ret;				\
+})
+
+static inline unsigned int __xchg_small(volatile void *ptr, unsigned int val,
+					unsigned int size)
+{
+	unsigned int shift;
+	u32 old32, mask, temp;
+	volatile u32 *ptr32;
+
+	/* Mask value to the correct size. */
+	mask = GENMASK((size * BITS_PER_BYTE) - 1, 0);
+	val &= mask;
+
+	/*
+	 * Calculate a shift & mask that correspond to the value we wish to
+	 * exchange within the naturally aligned 4 byte integerthat includes
+	 * it.
+	 */
+	shift = (unsigned long)ptr & 0x3;
+	shift *= BITS_PER_BYTE;
+	mask <<= shift;
+
+	/*
+	 * Calculate a pointer to the naturally aligned 4 byte integer that
+	 * includes our byte of interest, and load its value.
+	 */
+	ptr32 = (volatile u32 *)((unsigned long)ptr & ~0x3);
+
+	asm volatile (
+	"1:	ll.w		%0, %3		\n"
+	"	andn		%1, %0, %z4	\n"
+	"	or		%1, %1, %z5	\n"
+	"	sc.w		%1, %2		\n"
+	"	beqz		%1, 1b		\n"
+	: "=&r" (old32), "=&r" (temp), "=ZC" (*ptr32)
+	: "ZC" (*ptr32), "Jr" (mask), "Jr" (val << shift)
+	: "memory");
+
+	return (old32 & mask) >> shift;
+}
+
+static __always_inline unsigned long
+__xchg(volatile void *ptr, unsigned long x, int size)
+{
+	switch (size) {
+	case 1:
+	case 2:
+		return __xchg_small(ptr, x, size);
+
+	case 4:
+		return __xchg_asm("amswap_db.w", (volatile u32 *)ptr, (u32)x);
+
+	case 8:
+		return __xchg_asm("amswap_db.d", (volatile u64 *)ptr, (u64)x);
+
+	default:
+		BUILD_BUG();
+	}
+
+	return 0;
+}
+
+#define arch_xchg(ptr, x)						\
+({									\
+	__typeof__(*(ptr)) __res;					\
+									\
+	__res = (__typeof__(*(ptr)))					\
+		__xchg((ptr), (unsigned long)(x), sizeof(*(ptr)));	\
+									\
+	__res;								\
+})
+
+#define __cmpxchg_asm(ld, st, m, old, new)				\
+({									\
+	__typeof(old) __ret;						\
+									\
+	__asm__ __volatile__(						\
+	"1:	" ld "	%0, %2		# __cmpxchg_asm \n"		\
+	"	bne	%0, %z3, 2f			\n"		\
+	"	move	$t0, %z4			\n"		\
+	"	" st "	$t0, %1				\n"		\
+	"	beqz	$t0, 1b				\n"		\
+	"2:						\n"		\
+	__WEAK_LLSC_MB							\
+	: "=&r" (__ret), "=ZB"(*m)					\
+	: "ZB"(*m), "Jr" (old), "Jr" (new)				\
+	: "t0", "memory");						\
+									\
+	__ret;								\
+})
+
+static inline unsigned int __cmpxchg_small(volatile void *ptr, unsigned int old,
+					   unsigned int new, unsigned int size)
+{
+	unsigned int shift;
+	u32 old32, mask, temp;
+	volatile u32 *ptr32;
+
+	/* Mask inputs to the correct size. */
+	mask = GENMASK((size * BITS_PER_BYTE) - 1, 0);
+	old &= mask;
+	new &= mask;
+
+	/*
+	 * Calculate a shift & mask that correspond to the value we wish to
+	 * compare & exchange within the naturally aligned 4 byte integer
+	 * that includes it.
+	 */
+	shift = (unsigned long)ptr & 0x3;
+	shift *= BITS_PER_BYTE;
+	old <<= shift;
+	new <<= shift;
+	mask <<= shift;
+
+	/*
+	 * Calculate a pointer to the naturally aligned 4 byte integer that
+	 * includes our byte of interest, and load its value.
+	 */
+	ptr32 = (volatile u32 *)((unsigned long)ptr & ~0x3);
+
+	asm volatile (
+	"1:	ll.w		%0, %3		\n"
+	"	and		%1, %0, %z4	\n"
+	"	bne		%1, %z5, 2f	\n"
+	"	andn		%1, %0, %z4	\n"
+	"	or		%1, %1, %z6	\n"
+	"	sc.w		%1, %2		\n"
+	"	beqz		%1, 1b		\n"
+	"	b		3f		\n"
+	"2:					\n"
+	__WEAK_LLSC_MB
+	"3:					\n"
+	: "=&r" (old32), "=&r" (temp), "=ZC" (*ptr32)
+	: "ZC" (*ptr32), "Jr" (mask), "Jr" (old), "Jr" (new)
+	: "memory");
+
+	return (old32 & mask) >> shift;
+}
+
+static __always_inline unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, unsigned int size)
+{
+	switch (size) {
+	case 1:
+	case 2:
+		return __cmpxchg_small(ptr, old, new, size);
+
+	case 4:
+		return __cmpxchg_asm("ll.w", "sc.w", (volatile u32 *)ptr,
+				     (u32)old, new);
+
+	case 8:
+		return __cmpxchg_asm("ll.d", "sc.d", (volatile u64 *)ptr,
+				     (u64)old, new);
+
+	default:
+		BUILD_BUG();
+	}
+
+	return 0;
+}
+
+#define arch_cmpxchg_local(ptr, old, new)				\
+	((__typeof__(*(ptr)))						\
+		__cmpxchg((ptr),					\
+			  (unsigned long)(__typeof__(*(ptr)))(old),	\
+			  (unsigned long)(__typeof__(*(ptr)))(new),	\
+			  sizeof(*(ptr))))
+
+#define arch_cmpxchg(ptr, old, new)					\
+({									\
+	__typeof__(*(ptr)) __res;					\
+									\
+	__res = arch_cmpxchg_local((ptr), (old), (new));		\
+									\
+	__res;								\
+})
+
+#ifdef CONFIG_64BIT
+#define arch_cmpxchg64_local(ptr, o, n)					\
+  ({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	arch_cmpxchg_local((ptr), (o), (n));				\
+  })
+
+#define arch_cmpxchg64(ptr, o, n)					\
+  ({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	arch_cmpxchg((ptr), (o), (n));					\
+  })
+#else
+#include <asm-generic/cmpxchg-local.h>
+#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
+#define arch_cmpxchg64(ptr, o, n) arch_cmpxchg64_local((ptr), (o), (n))
+#endif
+
+#endif /* __ASM_CMPXCHG_H */