Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 542 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h
new file mode 100644
index 000000000..27183871e
--- /dev/null
+++ b/arch/powerpc/include/asm/cmpxchg.h
@@ -0,0 +1,542 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_CMPXCHG_H_
+#define _ASM_POWERPC_CMPXCHG_H_
+
+#ifdef __KERNEL__
+#include <linux/compiler.h>
+#include <asm/synch.h>
+#include <linux/bug.h>
+#include <asm/asm-405.h>
+
+#ifdef __BIG_ENDIAN
+#define BITOFF_CAL(size, off)	((sizeof(u32) - size - off) * BITS_PER_BYTE)
+#else
+#define BITOFF_CAL(size, off)	(off * BITS_PER_BYTE)
+#endif
+
+#define XCHG_GEN(type, sfx, cl)				\
+static inline u32 __xchg_##type##sfx(volatile void *p, u32 val)	\
+{								\
+	unsigned int prev, prev_mask, tmp, bitoff, off;		\
+								\
+	off = (unsigned long)p % sizeof(u32);			\
+	bitoff = BITOFF_CAL(sizeof(type), off);			\
+	p -= off;						\
+	val <<= bitoff;						\
+	prev_mask = (u32)(type)-1 << bitoff;			\
+								\
+	__asm__ __volatile__(					\
+"1:	lwarx   %0,0,%3\n"					\
+"	andc	%1,%0,%5\n"					\
+"	or	%1,%1,%4\n"					\
+	PPC405_ERR77(0,%3)					\
+"	stwcx.	%1,0,%3\n"					\
+"	bne-	1b\n"						\
+	: "=&r" (prev), "=&r" (tmp), "+m" (*(u32*)p)		\
+	: "r" (p), "r" (val), "r" (prev_mask)			\
+	: "cc", cl);						\
+								\
+	return prev >> bitoff;					\
+}
+
+#define CMPXCHG_GEN(type, sfx, br, br2, cl)			\
+static inline							\
+u32 __cmpxchg_##type##sfx(volatile void *p, u32 old, u32 new)	\
+{								\
+	unsigned int prev, prev_mask, tmp, bitoff, off;		\
+								\
+	off = (unsigned long)p % sizeof(u32);			\
+	bitoff = BITOFF_CAL(sizeof(type), off);			\
+	p -= off;						\
+	old <<= bitoff;						\
+	new <<= bitoff;						\
+	prev_mask = (u32)(type)-1 << bitoff;			\
+								\
+	__asm__ __volatile__(					\
+	br							\
+"1:	lwarx   %0,0,%3\n"					\
+"	and	%1,%0,%6\n"					\
+"	cmpw	0,%1,%4\n"					\
+"	bne-	2f\n"						\
+"	andc	%1,%0,%6\n"					\
+"	or	%1,%1,%5\n"					\
+	PPC405_ERR77(0,%3)					\
+"	stwcx.  %1,0,%3\n"					\
+"	bne-    1b\n"						\
+	br2							\
+	"\n"							\
+"2:"								\
+	: "=&r" (prev), "=&r" (tmp), "+m" (*(u32*)p)		\
+	: "r" (p), "r" (old), "r" (new), "r" (prev_mask)	\
+	: "cc", cl);						\
+								\
+	return prev >> bitoff;					\
+}
+
+/*
+ * Atomic exchange
+ *
+ * Changes the memory location '*p' to be val and returns
+ * the previous value stored there.
+ */
+
+XCHG_GEN(u8, _local, "memory");
+XCHG_GEN(u8, _relaxed, "cc");
+XCHG_GEN(u16, _local, "memory");
+XCHG_GEN(u16, _relaxed, "cc");
+
+static __always_inline unsigned long
+__xchg_u32_local(volatile void *p, unsigned long val)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%2 \n"
+	PPC405_ERR77(0,%2)
+"	stwcx.	%3,0,%2 \n\
+	bne-	1b"
+	: "=&r" (prev), "+m" (*(volatile unsigned int *)p)
+	: "r" (p), "r" (val)
+	: "cc", "memory");
+
+	return prev;
+}
+
+static __always_inline unsigned long
+__xchg_u32_relaxed(u32 *p, unsigned long val)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%2\n"
+	PPC405_ERR77(0, %2)
+"	stwcx.	%3,0,%2\n"
+"	bne-	1b"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (val)
+	: "cc");
+
+	return prev;
+}
+
+#ifdef CONFIG_PPC64
+static __always_inline unsigned long
+__xchg_u64_local(volatile void *p, unsigned long val)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__(
+"1:	ldarx	%0,0,%2 \n"
+	PPC405_ERR77(0,%2)
+"	stdcx.	%3,0,%2 \n\
+	bne-	1b"
+	: "=&r" (prev), "+m" (*(volatile unsigned long *)p)
+	: "r" (p), "r" (val)
+	: "cc", "memory");
+
+	return prev;
+}
+
+static __always_inline unsigned long
+__xchg_u64_relaxed(u64 *p, unsigned long val)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__(
+"1:	ldarx	%0,0,%2\n"
+	PPC405_ERR77(0, %2)
+"	stdcx.	%3,0,%2\n"
+"	bne-	1b"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (val)
+	: "cc");
+
+	return prev;
+}
+#endif
+
+static __always_inline unsigned long
+__xchg_local(void *ptr, unsigned long x, unsigned int size)
+{
+	switch (size) {
+	case 1:
+		return __xchg_u8_local(ptr, x);
+	case 2:
+		return __xchg_u16_local(ptr, x);
+	case 4:
+		return __xchg_u32_local(ptr, x);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __xchg_u64_local(ptr, x);
+#endif
+	}
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg");
+	return x;
+}
+
+static __always_inline unsigned long
+__xchg_relaxed(void *ptr, unsigned long x, unsigned int size)
+{
+	switch (size) {
+	case 1:
+		return __xchg_u8_relaxed(ptr, x);
+	case 2:
+		return __xchg_u16_relaxed(ptr, x);
+	case 4:
+		return __xchg_u32_relaxed(ptr, x);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __xchg_u64_relaxed(ptr, x);
+#endif
+	}
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local");
+	return x;
+}
+#define xchg_local(ptr,x)						     \
+  ({									     \
+     __typeof__(*(ptr)) _x_ = (x);					     \
+     (__typeof__(*(ptr))) __xchg_local((ptr),				     \
+     		(unsigned long)_x_, sizeof(*(ptr))); 			     \
+  })
+
+#define xchg_relaxed(ptr, x)						\
+({									\
+	__typeof__(*(ptr)) _x_ = (x);					\
+	(__typeof__(*(ptr))) __xchg_relaxed((ptr),			\
+			(unsigned long)_x_, sizeof(*(ptr)));		\
+})
+/*
+ * Compare and exchange - if *p == old, set it to new,
+ * and return the old value of *p.
+ */
+
+CMPXCHG_GEN(u8, , PPC_ATOMIC_ENTRY_BARRIER, PPC_ATOMIC_EXIT_BARRIER, "memory");
+CMPXCHG_GEN(u8, _local, , , "memory");
+CMPXCHG_GEN(u8, _acquire, , PPC_ACQUIRE_BARRIER, "memory");
+CMPXCHG_GEN(u8, _relaxed, , , "cc");
+CMPXCHG_GEN(u16, , PPC_ATOMIC_ENTRY_BARRIER, PPC_ATOMIC_EXIT_BARRIER, "memory");
+CMPXCHG_GEN(u16, _local, , , "memory");
+CMPXCHG_GEN(u16, _acquire, , PPC_ACQUIRE_BARRIER, "memory");
+CMPXCHG_GEN(u16, _relaxed, , , "cc");
+
+static __always_inline unsigned long
+__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
+{
+	unsigned int prev;
+
+	__asm__ __volatile__ (
+	PPC_ATOMIC_ENTRY_BARRIER
+"1:	lwarx	%0,0,%2		# __cmpxchg_u32\n\
+	cmpw	0,%0,%3\n\
+	bne-	2f\n"
+	PPC405_ERR77(0,%2)
+"	stwcx.	%4,0,%2\n\
+	bne-	1b"
+	PPC_ATOMIC_EXIT_BARRIER
+	"\n\
+2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc", "memory");
+
+	return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u32_local(volatile unsigned int *p, unsigned long old,
+			unsigned long new)
+{
+	unsigned int prev;
+
+	__asm__ __volatile__ (
+"1:	lwarx	%0,0,%2		# __cmpxchg_u32\n\
+	cmpw	0,%0,%3\n\
+	bne-	2f\n"
+	PPC405_ERR77(0,%2)
+"	stwcx.	%4,0,%2\n\
+	bne-	1b"
+	"\n\
+2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc", "memory");
+
+	return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u32_relaxed(u32 *p, unsigned long old, unsigned long new)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__ (
+"1:	lwarx	%0,0,%2		# __cmpxchg_u32_relaxed\n"
+"	cmpw	0,%0,%3\n"
+"	bne-	2f\n"
+	PPC405_ERR77(0, %2)
+"	stwcx.	%4,0,%2\n"
+"	bne-	1b\n"
+"2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc");
+
+	return prev;
+}
+
+/*
+ * cmpxchg family don't have order guarantee if cmp part fails, therefore we
+ * can avoid superfluous barriers if we use assembly code to implement
+ * cmpxchg() and cmpxchg_acquire(), however we don't do the similar for
+ * cmpxchg_release() because that will result in putting a barrier in the
+ * middle of a ll/sc loop, which is probably a bad idea. For example, this
+ * might cause the conditional store more likely to fail.
+ */
+static __always_inline unsigned long
+__cmpxchg_u32_acquire(u32 *p, unsigned long old, unsigned long new)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__ (
+"1:	lwarx	%0,0,%2		# __cmpxchg_u32_acquire\n"
+"	cmpw	0,%0,%3\n"
+"	bne-	2f\n"
+	PPC405_ERR77(0, %2)
+"	stwcx.	%4,0,%2\n"
+"	bne-	1b\n"
+	PPC_ACQUIRE_BARRIER
+	"\n"
+"2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc", "memory");
+
+	return prev;
+}
+
+#ifdef CONFIG_PPC64
+static __always_inline unsigned long
+__cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__ (
+	PPC_ATOMIC_ENTRY_BARRIER
+"1:	ldarx	%0,0,%2		# __cmpxchg_u64\n\
+	cmpd	0,%0,%3\n\
+	bne-	2f\n\
+	stdcx.	%4,0,%2\n\
+	bne-	1b"
+	PPC_ATOMIC_EXIT_BARRIER
+	"\n\
+2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc", "memory");
+
+	return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u64_local(volatile unsigned long *p, unsigned long old,
+			unsigned long new)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__ (
+"1:	ldarx	%0,0,%2		# __cmpxchg_u64\n\
+	cmpd	0,%0,%3\n\
+	bne-	2f\n\
+	stdcx.	%4,0,%2\n\
+	bne-	1b"
+	"\n\
+2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc", "memory");
+
+	return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u64_relaxed(u64 *p, unsigned long old, unsigned long new)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__ (
+"1:	ldarx	%0,0,%2		# __cmpxchg_u64_relaxed\n"
+"	cmpd	0,%0,%3\n"
+"	bne-	2f\n"
+"	stdcx.	%4,0,%2\n"
+"	bne-	1b\n"
+"2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc");
+
+	return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u64_acquire(u64 *p, unsigned long old, unsigned long new)
+{
+	unsigned long prev;
+
+	__asm__ __volatile__ (
+"1:	ldarx	%0,0,%2		# __cmpxchg_u64_acquire\n"
+"	cmpd	0,%0,%3\n"
+"	bne-	2f\n"
+"	stdcx.	%4,0,%2\n"
+"	bne-	1b\n"
+	PPC_ACQUIRE_BARRIER
+	"\n"
+"2:"
+	: "=&r" (prev), "+m" (*p)
+	: "r" (p), "r" (old), "r" (new)
+	: "cc", "memory");
+
+	return prev;
+}
+#endif
+
+static __always_inline unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
+	  unsigned int size)
+{
+	switch (size) {
+	case 1:
+		return __cmpxchg_u8(ptr, old, new);
+	case 2:
+		return __cmpxchg_u16(ptr, old, new);
+	case 4:
+		return __cmpxchg_u32(ptr, old, new);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __cmpxchg_u64(ptr, old, new);
+#endif
+	}
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg");
+	return old;
+}
+
+static __always_inline unsigned long
+__cmpxchg_local(void *ptr, unsigned long old, unsigned long new,
+	  unsigned int size)
+{
+	switch (size) {
+	case 1:
+		return __cmpxchg_u8_local(ptr, old, new);
+	case 2:
+		return __cmpxchg_u16_local(ptr, old, new);
+	case 4:
+		return __cmpxchg_u32_local(ptr, old, new);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __cmpxchg_u64_local(ptr, old, new);
+#endif
+	}
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_local");
+	return old;
+}
+
+static __always_inline unsigned long
+__cmpxchg_relaxed(void *ptr, unsigned long old, unsigned long new,
+		  unsigned int size)
+{
+	switch (size) {
+	case 1:
+		return __cmpxchg_u8_relaxed(ptr, old, new);
+	case 2:
+		return __cmpxchg_u16_relaxed(ptr, old, new);
+	case 4:
+		return __cmpxchg_u32_relaxed(ptr, old, new);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __cmpxchg_u64_relaxed(ptr, old, new);
+#endif
+	}
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_relaxed");
+	return old;
+}
+
+static __always_inline unsigned long
+__cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new,
+		  unsigned int size)
+{
+	switch (size) {
+	case 1:
+		return __cmpxchg_u8_acquire(ptr, old, new);
+	case 2:
+		return __cmpxchg_u16_acquire(ptr, old, new);
+	case 4:
+		return __cmpxchg_u32_acquire(ptr, old, new);
+#ifdef CONFIG_PPC64
+	case 8:
+		return __cmpxchg_u64_acquire(ptr, old, new);
+#endif
+	}
+	BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_acquire");
+	return old;
+}
+#define cmpxchg(ptr, o, n)						 \
+  ({									 \
+     __typeof__(*(ptr)) _o_ = (o);					 \
+     __typeof__(*(ptr)) _n_ = (n);					 \
+     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
+				    (unsigned long)_n_, sizeof(*(ptr))); \
+  })
+
+
+#define cmpxchg_local(ptr, o, n)					 \
+  ({									 \
+     __typeof__(*(ptr)) _o_ = (o);					 \
+     __typeof__(*(ptr)) _n_ = (n);					 \
+     (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_,	 \
+				    (unsigned long)_n_, sizeof(*(ptr))); \
+  })
+
+#define cmpxchg_relaxed(ptr, o, n)					\
+({									\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	(__typeof__(*(ptr))) __cmpxchg_relaxed((ptr),			\
+			(unsigned long)_o_, (unsigned long)_n_,		\
+			sizeof(*(ptr)));				\
+})
+
+#define cmpxchg_acquire(ptr, o, n)					\
+({									\
+	__typeof__(*(ptr)) _o_ = (o);					\
+	__typeof__(*(ptr)) _n_ = (n);					\
+	(__typeof__(*(ptr))) __cmpxchg_acquire((ptr),			\
+			(unsigned long)_o_, (unsigned long)_n_,		\
+			sizeof(*(ptr)));				\
+})
+#ifdef CONFIG_PPC64
+#define cmpxchg64(ptr, o, n)						\
+  ({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg((ptr), (o), (n));					\
+  })
+#define cmpxchg64_local(ptr, o, n)					\
+  ({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg_local((ptr), (o), (n));					\
+  })
+#define cmpxchg64_relaxed(ptr, o, n)					\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg_relaxed((ptr), (o), (n));				\
+})
+#define cmpxchg64_acquire(ptr, o, n)					\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg_acquire((ptr), (o), (n));				\
+})
+#else
+#include <asm-generic/cmpxchg-local.h>
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+#endif
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_CMPXCHG_H_ */