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authorIngo Molnar <mingo@elte.hu>2009-07-03 13:26:39 +0200
committerIngo Molnar <mingo@elte.hu>2009-07-03 13:26:39 +0200
commitb7882b7c65abb00194bdb3d4a22d27d70fcc59ba (patch)
treef22b1090c014f6d1da33c3791590d636104e8841 /arch/x86/lib
parentbbf2a330d92c5afccfd17592ba9ccd50f41cf748 (diff)
x86: atomic64: Move the 32-bit atomic64_t implementation to a .c file
Linus noted that the atomic64_t primitives are all inlines currently which is crazy because these functions have a large register footprint anyway. Move them to a separate file: arch/x86/lib/atomic64_32.c Also, while at it, rename all uses of 'unsigned long long' to the much shorter u64. This makes the appearance of the prototypes a lot nicer - and it also uncovered a few bugs where (yet unused) API variants had 'long' as their return type instead of u64. [ More intrusive changes are not yet done in this patch. ] Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> LKML-Reference: <alpine.LFD.2.01.0907021653030.3210@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/Makefile1
-rw-r--r--arch/x86/lib/atomic64_32.c216
2 files changed, 217 insertions, 0 deletions
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index f9d35632666..c3c657c8bb8 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -10,6 +10,7 @@ lib-y += usercopy_$(BITS).o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
ifeq ($(CONFIG_X86_32),y)
+ lib-y += atomic64_32.o
lib-y += checksum_32.o
lib-y += strstr_32.o
lib-y += semaphore_32.o string_32.o
diff --git a/arch/x86/lib/atomic64_32.c b/arch/x86/lib/atomic64_32.c
new file mode 100644
index 00000000000..d21e725d3d8
--- /dev/null
+++ b/arch/x86/lib/atomic64_32.c
@@ -0,0 +1,216 @@
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/processor.h>
+#include <asm/cmpxchg.h>
+#include <asm/atomic.h>
+
+static inline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new)
+{
+ asm volatile(
+
+ LOCK_PREFIX "cmpxchg8b (%[ptr])\n"
+
+ : "=A" (old)
+
+ : [ptr] "D" (ptr),
+ "A" (old),
+ "b" (ll_low(new)),
+ "c" (ll_high(new))
+
+ : "memory");
+
+ return old;
+}
+
+u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val)
+{
+ return cmpxchg8b(&ptr->counter, old_val, 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.
+ */
+
+u64 atomic64_xchg(atomic64_t *ptr, u64 new_val)
+{
+ u64 old_val;
+
+ do {
+ old_val = atomic_read(ptr);
+ } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
+
+ return old_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.
+ */
+void atomic64_set(atomic64_t *ptr, u64 new_val)
+{
+ atomic64_xchg(ptr, new_val);
+}
+
+/**
+ * atomic64_read - read atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically reads the value of @ptr and returns it.
+ */
+u64 atomic64_read(atomic64_t *ptr)
+{
+ u64 curr_val;
+
+ do {
+ curr_val = __atomic64_read(ptr);
+ } while (atomic64_cmpxchg(ptr, curr_val, curr_val) != curr_val);
+
+ return curr_val;
+}
+
+/**
+ * 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
+ */
+u64 atomic64_add_return(u64 delta, atomic64_t *ptr)
+{
+ u64 old_val, new_val;
+
+ do {
+ old_val = atomic_read(ptr);
+ new_val = old_val + delta;
+
+ } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
+
+ return new_val;
+}
+
+u64 atomic64_sub_return(u64 delta, atomic64_t *ptr)
+{
+ return atomic64_add_return(-delta, ptr);
+}
+
+u64 atomic64_inc_return(atomic64_t *ptr)
+{
+ return atomic64_add_return(1, ptr);
+}
+
+u64 atomic64_dec_return(atomic64_t *ptr)
+{
+ return atomic64_sub_return(1, ptr);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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 old_val = atomic64_sub_return(delta, ptr);
+
+ return old_val == 0;
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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)
+{
+ long long old_val = atomic64_add_return(delta, ptr);
+
+ return old_val < 0;
+}