From: Glauber Costa <glommer@redhat.com>
Date: Mon, 24 May 2010 20:08:05 -0400
Subject: [x86] grab atomic64 types from upstream
Message-id: <1274731689-21363-2-git-send-email-glommer@redhat.com>
Patchwork-id: 25794
O-Subject: [PATCH RHEL5.6/5.5.z v2 1/5] grab atomic64 types from upstream
Bugzilla: 570824
RH-Acked-by: Rik van Riel <riel@redhat.com>
RH-Acked-by: Zachary Amsden <zamsden@redhat.com>
RH-Acked-by: Jes Sorensen <Jes.Sorensen@redhat.com>

RH-Author: Glauber Costa <glommer@redhat.com>
RH-Bugzilla: 570824 and many, many others
RH-Upstream-status: N/A

Our kernel lacks support for atomic 64 bit operations in 32-bit platforms.
This patch is a verbatim copy of the related files from upstream kernels

Signed-off-by: Glauber Costa <glommer@redhat.com>

[ v2: don't make atomic64 include global. breaks rds.ko ]

diff --git a/arch/i386/kernel/pvclock.c b/arch/i386/kernel/pvclock.c
index 3b08ff5..94280dd 100644
--- a/arch/i386/kernel/pvclock.c
+++ b/arch/i386/kernel/pvclock.c
@@ -19,6 +19,10 @@
 #include <linux/percpu.h>
 #include <asm/pvclock.h>
 
+#ifdef CONFIG_X86_32
+#include <asm/atomic64_32.h>
+#endif
+
 /*
  * These are perodically updated
  *    xen: magic shared_info page
diff --git a/arch/i386/lib/Makefile b/arch/i386/lib/Makefile
index 920f0af..c6e74e1 100644
--- a/arch/i386/lib/Makefile
+++ b/arch/i386/lib/Makefile
@@ -4,7 +4,7 @@
 
 
 lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \
-	bitops.o
+	bitops.o atomic64_32.o
 
 lib-$(CONFIG_X86_USE_3DNOW) += mmx.o
 
diff --git a/arch/i386/lib/atomic64_32.c b/arch/i386/lib/atomic64_32.c
new file mode 100644
index 0000000..e226c27
--- /dev/null
+++ b/arch/i386/lib/atomic64_32.c
@@ -0,0 +1,230 @@
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include <asm/processor.h>
+#include <asm/atomic.h>
+#include <asm/atomic64_32.h>
+
+static noinline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new)
+{
+	u32 low = new;
+	u32 high = new >> 32;
+
+	asm volatile(
+		LOCK_PREFIX "cmpxchg8b %1\n"
+		     : "+A" (old), "+m" (*ptr)
+		     :  "b" (low),  "c" (high)
+		     );
+	return old;
+}
+
+u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val)
+{
+	return cmpxchg8b(&ptr->counter, old_val, new_val);
+}
+EXPORT_SYMBOL(atomic64_cmpxchg);
+
+/**
+ * atomic64_xchg - xchg atomic64 variable
+ * @ptr:      pointer to type atomic64_t
+ * @new_val:  value to assign
+ *
+ * Atomically xchgs the value of @ptr to @new_val and returns
+ * the old value.
+ */
+u64 atomic64_xchg(atomic64_t *ptr, u64 new_val)
+{
+	/*
+	 * Try first with a (possibly incorrect) assumption about
+	 * what we have there. We'll do two loops most likely,
+	 * but we'll get an ownership MESI transaction straight away
+	 * instead of a read transaction followed by a
+	 * flush-for-ownership transaction:
+	 */
+	u64 old_val, real_val = 0;
+
+	do {
+		old_val = real_val;
+
+		real_val = atomic64_cmpxchg(ptr, old_val, new_val);
+
+	} while (real_val != old_val);
+
+	return old_val;
+}
+EXPORT_SYMBOL(atomic64_xchg);
+
+/**
+ * atomic64_set - set atomic64 variable
+ * @ptr:      pointer to type atomic64_t
+ * @new_val:  value to assign
+ *
+ * Atomically sets the value of @ptr to @new_val.
+ */
+void atomic64_set(atomic64_t *ptr, u64 new_val)
+{
+	atomic64_xchg(ptr, new_val);
+}
+EXPORT_SYMBOL(atomic64_set);
+
+/**
+EXPORT_SYMBOL(atomic64_read);
+ * atomic64_add_return - add and return
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns @delta + *@ptr
+ */
+noinline u64 atomic64_add_return(u64 delta, atomic64_t *ptr)
+{
+	/*
+	 * Try first with a (possibly incorrect) assumption about
+	 * what we have there. We'll do two loops most likely,
+	 * but we'll get an ownership MESI transaction straight away
+	 * instead of a read transaction followed by a
+	 * flush-for-ownership transaction:
+	 */
+	u64 old_val, new_val, real_val = 0;
+
+	do {
+		old_val = real_val;
+		new_val = old_val + delta;
+
+		real_val = atomic64_cmpxchg(ptr, old_val, new_val);
+
+	} while (real_val != old_val);
+
+	return new_val;
+}
+EXPORT_SYMBOL(atomic64_add_return);
+
+u64 atomic64_sub_return(u64 delta, atomic64_t *ptr)
+{
+	return atomic64_add_return(-delta, ptr);
+}
+EXPORT_SYMBOL(atomic64_sub_return);
+
+u64 atomic64_inc_return(atomic64_t *ptr)
+{
+	return atomic64_add_return(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_inc_return);
+
+u64 atomic64_dec_return(atomic64_t *ptr)
+{
+	return atomic64_sub_return(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_dec_return);
+
+/**
+ * atomic64_add - add integer to atomic64 variable
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr.
+ */
+void atomic64_add(u64 delta, atomic64_t *ptr)
+{
+	atomic64_add_return(delta, ptr);
+}
+EXPORT_SYMBOL(atomic64_add);
+
+/**
+ * atomic64_sub - subtract the atomic64 variable
+ * @delta: integer value to subtract
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr.
+ */
+void atomic64_sub(u64 delta, atomic64_t *ptr)
+{
+	atomic64_add(-delta, ptr);
+}
+EXPORT_SYMBOL(atomic64_sub);
+
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @delta: integer value to subtract
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+int atomic64_sub_and_test(u64 delta, atomic64_t *ptr)
+{
+	u64 new_val = atomic64_sub_return(delta, ptr);
+
+	return new_val == 0;
+}
+EXPORT_SYMBOL(atomic64_sub_and_test);
+
+/**
+ * atomic64_inc - increment atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1.
+ */
+void atomic64_inc(atomic64_t *ptr)
+{
+	atomic64_add(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_inc);
+
+/**
+ * atomic64_dec - decrement atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1.
+ */
+void atomic64_dec(atomic64_t *ptr)
+{
+	atomic64_sub(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_dec);
+
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+int atomic64_dec_and_test(atomic64_t *ptr)
+{
+	return atomic64_sub_and_test(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_dec_and_test);
+
+/**
+ * atomic64_inc_and_test - increment and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+int atomic64_inc_and_test(atomic64_t *ptr)
+{
+	return atomic64_sub_and_test(-1, ptr);
+}
+EXPORT_SYMBOL(atomic64_inc_and_test);
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+int atomic64_add_negative(u64 delta, atomic64_t *ptr)
+{
+	s64 new_val = atomic64_add_return(delta, ptr);
+
+	return new_val < 0;
+}
+EXPORT_SYMBOL(atomic64_add_negative);
diff --git a/include/asm-i386/atomic64_32.h b/include/asm-i386/atomic64_32.h
new file mode 100644
index 0000000..03027bf
--- /dev/null
+++ b/include/asm-i386/atomic64_32.h
@@ -0,0 +1,160 @@
+#ifndef _ASM_X86_ATOMIC64_32_H
+#define _ASM_X86_ATOMIC64_32_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/processor.h>
+//#include <asm/cmpxchg.h>
+
+/* An 64bit atomic type */
+
+typedef struct {
+	u64 __aligned(8) counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(val)	{ (val) }
+
+extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val);
+
+/**
+ * atomic64_xchg - xchg atomic64 variable
+ * @ptr:      pointer to type atomic64_t
+ * @new_val:  value to assign
+ *
+ * Atomically xchgs the value of @ptr to @new_val and returns
+ * the old value.
+ */
+extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val);
+
+/**
+ * atomic64_set - set atomic64 variable
+ * @ptr:      pointer to type atomic64_t
+ * @new_val:  value to assign
+ *
+ * Atomically sets the value of @ptr to @new_val.
+ */
+extern void atomic64_set(atomic64_t *ptr, u64 new_val);
+
+/**
+ * atomic64_read - read atomic64 variable
+ * @ptr:      pointer to type atomic64_t
+ *
+ * Atomically reads the value of @ptr and returns it.
+ */
+static inline u64 atomic64_read(atomic64_t *ptr)
+{
+	u64 res;
+
+	/*
+	 * Note, we inline this atomic64_t primitive because
+	 * it only clobbers EAX/EDX and leaves the others
+	 * untouched. We also (somewhat subtly) rely on the
+	 * fact that cmpxchg8b returns the current 64-bit value
+	 * of the memory location we are touching:
+	 */
+	asm volatile(
+		"mov %%ebx, %%eax\n\t"
+		"mov %%ecx, %%edx\n\t"
+		LOCK_PREFIX "cmpxchg8b %1\n"
+			: "=&A" (res)
+			: "m" (*ptr)
+		);
+
+	return res;
+}
+
+extern u64 atomic64_read(atomic64_t *ptr);
+
+/**
+ * atomic64_add_return - add and return
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns @delta + *@ptr
+ */
+extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr);
+
+/*
+ * Other variants with different arithmetic operators:
+ */
+extern u64 atomic64_sub_return(u64 delta, atomic64_t *ptr);
+extern u64 atomic64_inc_return(atomic64_t *ptr);
+extern u64 atomic64_dec_return(atomic64_t *ptr);
+
+/**
+ * atomic64_add - add integer to atomic64 variable
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr.
+ */
+extern void atomic64_add(u64 delta, atomic64_t *ptr);
+
+/**
+ * atomic64_sub - subtract the atomic64 variable
+ * @delta: integer value to subtract
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr.
+ */
+extern void atomic64_sub(u64 delta, atomic64_t *ptr);
+
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @delta: integer value to subtract
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr);
+
+/**
+ * atomic64_inc - increment atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1.
+ */
+extern void atomic64_inc(atomic64_t *ptr);
+
+/**
+ * atomic64_dec - decrement atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1.
+ */
+extern void atomic64_dec(atomic64_t *ptr);
+
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+extern int atomic64_dec_and_test(atomic64_t *ptr);
+
+/**
+ * atomic64_inc_and_test - increment and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+extern int atomic64_inc_and_test(atomic64_t *ptr);
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+extern int atomic64_add_negative(u64 delta, atomic64_t *ptr);
+
+#endif /* _ASM_X86_ATOMIC64_32_H */