From 8c0a3d9e5c169fc9d0f246ab59362b658b029ad7 Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Sat, 29 Sep 2012 01:05:31 -0400
Subject: microblaze port

based on initial work by rdp, with heavy modifications. some features
including threads are untested because qemu app-level emulation seems
to be broken and I do not have a proper system image for testing.
---
 arch/microblaze/atomic.h | 151 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 151 insertions(+)
 create mode 100644 arch/microblaze/atomic.h

(limited to 'arch/microblaze/atomic.h')

diff --git a/arch/microblaze/atomic.h b/arch/microblaze/atomic.h
new file mode 100644
index 00000000..ee7aa256
--- /dev/null
+++ b/arch/microblaze/atomic.h
@@ -0,0 +1,151 @@
+#ifndef _INTERNAL_ATOMIC_H
+#define _INTERNAL_ATOMIC_H
+
+#include <stdint.h>
+
+static inline int a_ctz_l(unsigned long x)
+{
+	static const char debruijn32[32] = {
+		0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
+		31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
+	};
+	return debruijn32[(x&-x)*0x076be629 >> 27];
+}
+
+static inline int a_ctz_64(uint64_t x)
+{
+	uint32_t y = x;
+	if (!y) {
+		y = x>>32;
+		return 32 + a_ctz_l(y);
+	}
+	return a_ctz_l(y);
+}
+
+static inline int a_cas_1(volatile int *p, int t, int s)
+{
+	register int tmp;
+	do {
+		__asm__ __volatile__ ("lwx %0, %1, r0"
+			: "=r"(tmp) : "r"(p) : "memory");
+		if (tmp != t) return tmp;
+		__asm__ __volatile__ ("swx %2, %1, r0 ; addic %0, r0, 0"
+			: "=r"(tmp) : "r"(p), "r"(s) : "cc", "memory");
+	} while (tmp);
+	return t;
+}
+
+static inline int a_cas(volatile int *p, int t, int s)
+{
+	register int old, tmp;
+	__asm__ __volatile__ (
+		"	addi %0, r0, 0\n"
+		"1:	lwx %0, %2, r0\n"
+		"	rsubk %1, %0, %3\n"
+		"	bnei %1, 1f\n"
+		"	swx %4, %2, r0\n"
+		"	addic %1, r0, 0\n"
+		"	bnei %1, 1b\n"
+		"1:	"
+		: "=&r"(old), "=&r"(tmp)
+		: "r"(p), "r"(t), "r"(s)
+		: "cc", "memory" );
+	return old;
+}
+
+static inline void *a_cas_p(volatile void *p, void *t, void *s)
+{
+	return (void *)a_cas(p, (int)t, (int)s);
+}
+
+static inline long a_cas_l(volatile void *p, long t, long s)
+{
+	return a_cas(p, t, s);
+}
+
+static inline int a_swap(volatile int *x, int v)
+{
+	register int old, tmp;
+	__asm__ __volatile__ (
+		"	addi %0, r0, 0\n"
+		"1:	lwx %0, %2, r0\n"
+		"	swx %3, %2, r0\n"
+		"	addic %1, r0, 0\n"
+		"	bnei %1, 1b\n"
+		"1:	"
+		: "=&r"(old), "=&r"(tmp)
+		: "r"(x), "r"(v)
+		: "cc", "memory" );
+	return old;
+}
+
+static inline int a_fetch_add(volatile int *x, int v)
+{
+	register int new, tmp;
+	__asm__ __volatile__ (
+		"	addi %0, r0, 0\n"
+		"1:	lwx %0, %2, r0\n"
+		"	addk %0, %0, %3\n"
+		"	swx %0, %2, r0\n"
+		"	addic %1, r0, 0\n"
+		"	bnei %1, 1b\n"
+		"1:	"
+		: "=&r"(new), "=&r"(tmp)
+		: "r"(x), "r"(v)
+		: "cc", "memory" );
+	return new-v;
+}
+
+static inline void a_inc(volatile int *x)
+{
+	a_fetch_add(x, 1);
+}
+
+static inline void a_dec(volatile int *x)
+{
+	a_fetch_add(x, -1);
+}
+
+static inline void a_store(volatile int *p, int x)
+{
+	*p=x;
+}
+
+static inline void a_spin()
+{
+}
+
+static inline void a_crash()
+{
+	*(volatile char *)0=0;
+}
+
+static inline void a_and(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, old&v) != old);
+}
+
+static inline void a_or(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, old|v) != old);
+}
+
+static inline void a_and_64(volatile uint64_t *p, uint64_t v)
+{
+	union { uint64_t v; uint32_t r[2]; } u = { v };
+	a_and((int *)p, u.r[0]);
+	a_and((int *)p+1, u.r[1]);
+}
+
+static inline void a_or_64(volatile uint64_t *p, uint64_t v)
+{
+	union { uint64_t v; uint32_t r[2]; } u = { v };
+	a_or((int *)p, u.r[0]);
+	a_or((int *)p+1, u.r[1]);
+}
+
+#endif
-- 
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