Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6

27 files changed, 42 insertions, 396 deletions

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index b22f003eaa6d..d2703cda61ea 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -908,11 +908,6 @@ config IRQBALANCE
           The default yes will allow the kernel to do irq load balancing.
           Saying no will keep the kernel from doing irq load balancing.
 
-config HAVE_DEC_LOCK
-        bool
-        depends on (SMP || PREEMPT) && X86_CMPXCHG
-        default y
-
 # turning this on wastes a bunch of space.
 # Summit needs it only when NUMA is on
 config BOOT_IOREMAP
diff --git a/arch/i386/lib/Makefile b/arch/i386/lib/Makefile
index 7b1932d20f96..914933e9ec3d 100644
--- a/arch/i386/lib/Makefile
+++ b/arch/i386/lib/Makefile
@@ -7,4 +7,3 @@ lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \
         bitops.o
 
 lib-$(CONFIG_X86_USE_3DNOW) += mmx.o
-lib-$(CONFIG_HAVE_DEC_LOCK) += dec_and_lock.o
diff --git a/arch/i386/lib/dec_and_lock.c b/arch/i386/lib/dec_and_lock.c
deleted file mode 100644
index 8b81b2524fa6..000000000000
--- a/arch/i386/lib/dec_and_lock.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * x86 version of "atomic_dec_and_lock()" using
- * the atomic "cmpxchg" instruction.
- *
- * (For CPU's lacking cmpxchg, we use the slow
- * generic version, and this one never even gets
- * compiled).
- */
-
-#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <asm/atomic.h>
-
-int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
-{
-        int counter;
-        int newcount;
-
-repeat:
-        counter = atomic_read(atomic);
-        newcount = counter-1;
-
-        if (!newcount)
-                goto slow_path;
-
-        asm volatile("lock; cmpxchgl %1,%2"
-                :"=a" (newcount)
-                :"r" (newcount), "m" (atomic->counter), "0" (counter));
-
-        /* If the above failed, "eax" will have changed */
-        if (newcount != counter)
-                goto repeat;
-        return 0;
-
-slow_path:
-        spin_lock(lock);
-        if (atomic_dec_and_test(atomic))
-                return 1;
-        spin_unlock(lock);
-        return 0;
-}
-EXPORT_SYMBOL(_atomic_dec_and_lock);
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index ed25d66c8d50..945c15a0722b 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -298,11 +298,6 @@ config PREEMPT
 
 source "mm/Kconfig"
 
-config HAVE_DEC_LOCK
-        bool
-        depends on (SMP || PREEMPT)
-        default y
-
 config IA32_SUPPORT
         bool "Support for Linux/x86 binaries"
         help
diff --git a/arch/ia64/lib/Makefile b/arch/ia64/lib/Makefile
index 799407e7726f..cb1af597370b 100644
--- a/arch/ia64/lib/Makefile
+++ b/arch/ia64/lib/Makefile
@@ -15,7 +15,6 @@ lib-$(CONFIG_ITANIUM)	+= copy_page.o copy_user.o memcpy.o
 lib-$(CONFIG_MCKINLEY)  += copy_page_mck.o memcpy_mck.o
 lib-$(CONFIG_PERFMON)   += carta_random.o
 lib-$(CONFIG_MD_RAID5)  += xor.o
-lib-$(CONFIG_HAVE_DEC_LOCK) += dec_and_lock.o
 
 AFLAGS___divdi3.o       =
 AFLAGS___udivdi3.o      = -DUNSIGNED
diff --git a/arch/ia64/lib/dec_and_lock.c b/arch/ia64/lib/dec_and_lock.c
deleted file mode 100644
index c7ce92f968f1..000000000000
--- a/arch/ia64/lib/dec_and_lock.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (C) 2003 Jerome Marchand, Bull S.A.
- *      Cleaned up by David Mosberger-Tang <davidm@hpl.hp.com>
- *
- * This file is released under the GPLv2, or at your option any later version.
- *
- * ia64 version of "atomic_dec_and_lock()" using the atomic "cmpxchg" instruction.  This
- * code is an adaptation of the x86 version of "atomic_dec_and_lock()".
- */
-
-#include <linux/compiler.h>
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-
-/*
- * Decrement REFCOUNT and if the count reaches zero, acquire the spinlock.  Both of these
- * operations have to be done atomically, so that the count doesn't drop to zero without
- * acquiring the spinlock first.
- */
-int
-_atomic_dec_and_lock (atomic_t *refcount, spinlock_t *lock)
-{
-        int old, new;
-
-        do {
-                old = atomic_read(refcount);
-                new = old - 1;
-
-                if (unlikely (old == 1)) {
-                        /* oops, we may be decrementing to zero, do it the slow way... */
-                        spin_lock(lock);
-                        if (atomic_dec_and_test(refcount))
-                                return 1;
-                        spin_unlock(lock);
-                        return 0;
-                }
-        } while (cmpxchg(&refcount->counter, old, new) != old);
-        return 0;
-}
-
-EXPORT_SYMBOL(_atomic_dec_and_lock);
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 1ef3987ebc6a..4d100f3886e1 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -220,11 +220,6 @@ config PREEMPT
           Say Y here if you are building a kernel for a desktop, embedded
           or real-time system.  Say N if you are unsure.
 
-config HAVE_DEC_LOCK
-        bool
-        depends on (SMP || PREEMPT)
-        default n
-
 config SMP
         bool "Symmetric multi-processing support"
         ---help---
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 0eb71ac303af..4cd724c05700 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1009,10 +1009,6 @@ config GENERIC_CALIBRATE_DELAY
         bool
         default y
 
-config HAVE_DEC_LOCK
-        bool
-        default y
-
 #
 # Select some configuration options automatically based on user selections.
 #
diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile
index 21b92b9dd013..037303412909 100644
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -2,7 +2,7 @@
 # Makefile for MIPS-specific library files..
 #
 
-lib-y   += csum_partial_copy.o dec_and_lock.o memcpy.o promlib.o \
+lib-y   += csum_partial_copy.o memcpy.o promlib.o \
            strlen_user.o strncpy_user.o strnlen_user.o
 
 obj-y   += iomap.o
diff --git a/arch/mips/lib/dec_and_lock.c b/arch/mips/lib/dec_and_lock.c
deleted file mode 100644
index fd82c84a93b7..000000000000
--- a/arch/mips/lib/dec_and_lock.c
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * MIPS version of atomic_dec_and_lock() using cmpxchg
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-/*
- * This is an implementation of the notion of "decrement a
- * reference count, and return locked if it decremented to zero".
- *
- * This implementation can be used on any architecture that
- * has a cmpxchg, and where atomic->value is an int holding
- * the value of the atomic (i.e. the high bits aren't used
- * for a lock or anything like that).
- */
-int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
-{
-        int counter;
-        int newcount;
-
-        for (;;) {
-                counter = atomic_read(atomic);
-                newcount = counter - 1;
-                if (!newcount)
-                        break;          /* do it the slow way */
-
-                newcount = cmpxchg(&atomic->counter, counter, newcount);
-                if (newcount == counter)
-                        return 0;
-        }
-
-        spin_lock(lock);
-        if (atomic_dec_and_test(atomic))
-                return 1;
-        spin_unlock(lock);
-        return 0;
-}
-
-EXPORT_SYMBOL(_atomic_dec_and_lock);
diff --git a/arch/ppc/Kconfig b/arch/ppc/Kconfig
index 347ea284140b..776941c75672 100644
--- a/arch/ppc/Kconfig
+++ b/arch/ppc/Kconfig
@@ -26,10 +26,6 @@ config GENERIC_CALIBRATE_DELAY
         bool
         default y
 
-config HAVE_DEC_LOCK
-        bool
-        default y
-
 config PPC
         bool
         default y
diff --git a/arch/ppc/lib/Makefile b/arch/ppc/lib/Makefile
index f1e1fb4144f0..50358e4ea159 100644
--- a/arch/ppc/lib/Makefile
+++ b/arch/ppc/lib/Makefile
@@ -2,7 +2,7 @@
 # Makefile for ppc-specific library files..
 #
 
-obj-y                   := checksum.o string.o strcase.o dec_and_lock.o div64.o
+obj-y                   := checksum.o string.o strcase.o div64.o
 
 obj-$(CONFIG_8xx)       += rheap.o
 obj-$(CONFIG_CPM2)      += rheap.o
diff --git a/arch/ppc/lib/dec_and_lock.c b/arch/ppc/lib/dec_and_lock.c
deleted file mode 100644
index b18f0d9a00fc..000000000000
--- a/arch/ppc/lib/dec_and_lock.c
+++ /dev/null
@@ -1,38 +0,0 @@
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-/*
- * This is an implementation of the notion of "decrement a
- * reference count, and return locked if it decremented to zero".
- *
- * This implementation can be used on any architecture that
- * has a cmpxchg, and where atomic->value is an int holding
- * the value of the atomic (i.e. the high bits aren't used
- * for a lock or anything like that).
- */
-int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
-{
-        int counter;
-        int newcount;
-
-        for (;;) {
-                counter = atomic_read(atomic);
-                newcount = counter - 1;
-                if (!newcount)
-                        break;          /* do it the slow way */
-
-                newcount = cmpxchg(&atomic->counter, counter, newcount);
-                if (newcount == counter)
-                        return 0;
-        }
-
-        spin_lock(lock);
-        if (atomic_dec_and_test(atomic))
-                return 1;
-        spin_unlock(lock);
-        return 0;
-}
-
-EXPORT_SYMBOL(_atomic_dec_and_lock);
diff --git a/arch/ppc64/Kconfig b/arch/ppc64/Kconfig
index deca68ad644a..c658650af429 100644
--- a/arch/ppc64/Kconfig
+++ b/arch/ppc64/Kconfig
@@ -28,10 +28,6 @@ config GENERIC_ISA_DMA
         bool
         default y
 
-config HAVE_DEC_LOCK
-        bool
-        default y
-
 config EARLY_PRINTK
         bool
         default y
diff --git a/arch/ppc64/lib/Makefile b/arch/ppc64/lib/Makefile
index 76fbfa9f706f..0b6e967de948 100644
--- a/arch/ppc64/lib/Makefile
+++ b/arch/ppc64/lib/Makefile
@@ -2,7 +2,7 @@
 # Makefile for ppc64-specific library files..
 #
 
-lib-y := checksum.o dec_and_lock.o string.o strcase.o
+lib-y := checksum.o string.o strcase.o
 lib-y += copypage.o memcpy.o copyuser.o usercopy.o
 
 # Lock primitives are defined as no-ops in include/linux/spinlock.h
diff --git a/arch/ppc64/lib/dec_and_lock.c b/arch/ppc64/lib/dec_and_lock.c
deleted file mode 100644
index 7b9d4da5cf92..000000000000
--- a/arch/ppc64/lib/dec_and_lock.c
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * ppc64 version of atomic_dec_and_lock() using cmpxchg
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-/*
- * This is an implementation of the notion of "decrement a
- * reference count, and return locked if it decremented to zero".
- *
- * This implementation can be used on any architecture that
- * has a cmpxchg, and where atomic->value is an int holding
- * the value of the atomic (i.e. the high bits aren't used
- * for a lock or anything like that).
- */
-int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
-{
-        int counter;
-        int newcount;
-
-        for (;;) {
-                counter = atomic_read(atomic);
-                newcount = counter - 1;
-                if (!newcount)
-                        break;          /* do it the slow way */
-
-                newcount = cmpxchg(&atomic->counter, counter, newcount);
-                if (newcount == counter)
-                        return 0;
-        }
-
-        spin_lock(lock);
-        if (atomic_dec_and_test(atomic))
-                return 1;
-        spin_unlock(lock);
-        return 0;
-}
-
-EXPORT_SYMBOL(_atomic_dec_and_lock);
diff --git a/arch/sparc64/Kconfig.debug b/arch/sparc64/Kconfig.debug
index cd8d39fb954d..af0e9411b83e 100644
--- a/arch/sparc64/Kconfig.debug
+++ b/arch/sparc64/Kconfig.debug
@@ -33,14 +33,6 @@ config DEBUG_BOOTMEM
         depends on DEBUG_KERNEL
         bool "Debug BOOTMEM initialization"
 
-# We have a custom atomic_dec_and_lock() implementation but it's not
-# compatible with spinlock debugging so we need to fall back on
-# the generic version in that case.
-config HAVE_DEC_LOCK
-        bool
-        depends on SMP && !DEBUG_SPINLOCK
-        default y
-
 config MCOUNT
         bool
         depends on STACK_DEBUG
diff --git a/arch/sparc64/kernel/sparc64_ksyms.c b/arch/sparc64/kernel/sparc64_ksyms.c
index cbb5e59824e5..fb7a5370dbfc 100644
--- a/arch/sparc64/kernel/sparc64_ksyms.c
+++ b/arch/sparc64/kernel/sparc64_ksyms.c
@@ -163,9 +163,6 @@ EXPORT_SYMBOL(atomic64_add);
 EXPORT_SYMBOL(atomic64_add_ret);
 EXPORT_SYMBOL(atomic64_sub);
 EXPORT_SYMBOL(atomic64_sub_ret);
-#ifdef CONFIG_SMP
-EXPORT_SYMBOL(_atomic_dec_and_lock);
-#endif
 
 /* Atomic bit operations. */
 EXPORT_SYMBOL(test_and_set_bit);
diff --git a/arch/sparc64/lib/Makefile b/arch/sparc64/lib/Makefile
index d968aebe83b2..c295806500f7 100644
--- a/arch/sparc64/lib/Makefile
+++ b/arch/sparc64/lib/Makefile
@@ -14,6 +14,4 @@ lib-y := PeeCeeI.o copy_page.o clear_page.o strlen.o strncmp.o \
          copy_in_user.o user_fixup.o memmove.o \
          mcount.o ipcsum.o rwsem.o xor.o find_bit.o delay.o
 
-lib-$(CONFIG_HAVE_DEC_LOCK) += dec_and_lock.o
-
 obj-y += iomap.o
diff --git a/arch/sparc64/lib/dec_and_lock.S b/arch/sparc64/lib/dec_and_lock.S
deleted file mode 100644
index 8ee288dd0afc..000000000000
--- a/arch/sparc64/lib/dec_and_lock.S
+++ /dev/null
@@ -1,80 +0,0 @@
-/* $Id: dec_and_lock.S,v 1.5 2001/11/18 00:12:56 davem Exp $
- * dec_and_lock.S: Sparc64 version of "atomic_dec_and_lock()"
- *                 using cas and ldstub instructions.
- *
- * Copyright (C) 2000 David S. Miller (davem@redhat.com)
- */
-#include <linux/config.h>
-#include <asm/thread_info.h>
-
-        .text
-        .align  64
-
-        /* CAS basically works like this:
-         *
-         * void CAS(MEM, REG1, REG2)
-         * {
-         *   START_ATOMIC();
-         *   if (*(MEM) == REG1) {
-         *     TMP = *(MEM);
-         *     *(MEM) = REG2;
-         *     REG2 = TMP;
-         *   } else
-         *     REG2 = *(MEM);
-         *   END_ATOMIC();
-         * }
-         */
-
-        .globl  _atomic_dec_and_lock
-_atomic_dec_and_lock:   /* %o0 = counter, %o1 = lock */
-loop1:  lduw    [%o0], %g2
-        subcc   %g2, 1, %g7
-        be,pn   %icc, start_to_zero
-         nop
-nzero:  cas     [%o0], %g2, %g7
-        cmp     %g2, %g7
-        bne,pn  %icc, loop1
-         mov    0, %g1
-
-out:
-        membar  #StoreLoad | #StoreStore
-        retl
-         mov    %g1, %o0
-start_to_zero:
-#ifdef CONFIG_PREEMPT
-        ldsw    [%g6 + TI_PRE_COUNT], %g3
-        add     %g3, 1, %g3
-        stw     %g3, [%g6 + TI_PRE_COUNT]
-#endif
-to_zero:
-        ldstub  [%o1], %g3
-        membar  #StoreLoad | #StoreStore
-        brnz,pn %g3, spin_on_lock
-         nop
-loop2:  cas     [%o0], %g2, %g7         /* ASSERT(g7 == 0) */
-        cmp     %g2, %g7
-
-        be,pt   %icc, out
-         mov    1, %g1
-        lduw    [%o0], %g2
-        subcc   %g2, 1, %g7
-        be,pn   %icc, loop2
-         nop
-        membar  #StoreStore | #LoadStore
-        stb     %g0, [%o1]
-#ifdef CONFIG_PREEMPT
-        ldsw    [%g6 + TI_PRE_COUNT], %g3
-        sub     %g3, 1, %g3
-        stw     %g3, [%g6 + TI_PRE_COUNT]
-#endif
-
-        b,pt    %xcc, nzero
-         nop
-spin_on_lock:
-        ldub    [%o1], %g3
-        membar  #LoadLoad
-        brnz,pt %g3, spin_on_lock
-         nop
-        ba,pt   %xcc, to_zero
-         nop
-        nop
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index e63323e03ea9..0969d570f3b5 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -277,11 +277,6 @@ source "mm/Kconfig"
 config HAVE_ARCH_EARLY_PFN_TO_NID
         def_bool y
 
-config HAVE_DEC_LOCK
-        bool
-        depends on SMP
-        default y
-
 config NR_CPUS
         int "Maximum number of CPUs (2-256)"
         range 2 256
diff --git a/arch/x86_64/kernel/x8664_ksyms.c b/arch/x86_64/kernel/x8664_ksyms.c
index 68ec03070e5a..fd99ddd009bc 100644
--- a/arch/x86_64/kernel/x8664_ksyms.c
+++ b/arch/x86_64/kernel/x8664_ksyms.c
@@ -178,10 +178,6 @@ EXPORT_SYMBOL(rwsem_down_write_failed_thunk);
 
 EXPORT_SYMBOL(empty_zero_page);
 
-#ifdef CONFIG_HAVE_DEC_LOCK
-EXPORT_SYMBOL(_atomic_dec_and_lock);
-#endif
-
 EXPORT_SYMBOL(die_chain);
 EXPORT_SYMBOL(register_die_notifier);
 
diff --git a/arch/x86_64/lib/Makefile b/arch/x86_64/lib/Makefile
index 6b26a1c1e9ff..bba5db6cebd6 100644
--- a/arch/x86_64/lib/Makefile
+++ b/arch/x86_64/lib/Makefile
@@ -10,5 +10,3 @@ lib-y := csum-partial.o csum-copy.o csum-wrappers.o delay.o \
         usercopy.o getuser.o putuser.o  \
         thunk.o clear_page.o copy_page.o bitstr.o bitops.o
 lib-y += memcpy.o memmove.o memset.o copy_user.o
-
-lib-$(CONFIG_HAVE_DEC_LOCK) += dec_and_lock.o
diff --git a/arch/x86_64/lib/dec_and_lock.c b/arch/x86_64/lib/dec_and_lock.c
deleted file mode 100644
index ab43394dc775..000000000000
--- a/arch/x86_64/lib/dec_and_lock.c
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * x86 version of "atomic_dec_and_lock()" using
- * the atomic "cmpxchg" instruction.
- *
- * (For CPU's lacking cmpxchg, we use the slow
- * generic version, and this one never even gets
- * compiled).
- */
-
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-
-int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
-{
-        int counter;
-        int newcount;
-
-repeat:
-        counter = atomic_read(atomic);
-        newcount = counter-1;
-
-        if (!newcount)
-                goto slow_path;
-
-        asm volatile("lock; cmpxchgl %1,%2"
-                :"=a" (newcount)
-                :"r" (newcount), "m" (atomic->counter), "0" (counter));
-
-        /* If the above failed, "eax" will have changed */
-        if (newcount != counter)
-                goto repeat;
-        return 0;
-
-slow_path:
-        spin_lock(lock);
-        if (atomic_dec_and_test(atomic))
-                return 1;
-        spin_unlock(lock);
-        return 0;
-}
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 2b6257bec4c3..7e841aa2a4aa 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -26,10 +26,6 @@ config RWSEM_XCHGADD_ALGORITHM
         bool
         default y
 
-config HAVE_DEC_LOCK
-        bool
-        default y
-
 config GENERIC_HARDIRQS
         bool
         default y
diff --git a/fs/compat.c b/fs/compat.c
index ac3fb9ed8eea..a719e158e002 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -44,6 +44,8 @@
 #include <linux/nfsd/syscall.h>
 #include <linux/personality.h>
 #include <linux/rwsem.h>
+#include <linux/acct.h>
+#include <linux/mm.h>
 
 #include <net/sock.h>           /* siocdevprivate_ioctl */
 
@@ -1487,6 +1489,8 @@ int compat_do_execve(char * filename,
 
                 /* execve success */
                 security_bprm_free(bprm);
+                acct_update_integrals(current);
+                update_mem_hiwater(current);
                 kfree(bprm);
                 return retval;
         }
diff --git a/lib/dec_and_lock.c b/lib/dec_and_lock.c
index 2377af057d09..305a9663aee3 100644
--- a/lib/dec_and_lock.c
+++ b/lib/dec_and_lock.c
@@ -1,7 +1,41 @@
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <asm/atomic.h>
+#include <asm/system.h>
 
+#ifdef __HAVE_ARCH_CMPXCHG
+/*
+ * This is an implementation of the notion of "decrement a
+ * reference count, and return locked if it decremented to zero".
+ *
+ * This implementation can be used on any architecture that
+ * has a cmpxchg, and where atomic->value is an int holding
+ * the value of the atomic (i.e. the high bits aren't used
+ * for a lock or anything like that).
+ */
+int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
+{
+        int counter;
+        int newcount;
+
+        for (;;) {
+                counter = atomic_read(atomic);
+                newcount = counter - 1;
+                if (!newcount)
+                        break;          /* do it the slow way */
+
+                newcount = cmpxchg(&atomic->counter, counter, newcount);
+                if (newcount == counter)
+                        return 0;
+        }
+
+        spin_lock(lock);
+        if (atomic_dec_and_test(atomic))
+                return 1;
+        spin_unlock(lock);
+        return 0;
+}
+#else
 /*
  * This is an architecture-neutral, but slow,
  * implementation of the notion of "decrement
@@ -33,5 +67,6 @@ int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
         spin_unlock(lock);
         return 0;
 }
+#endif
 
 EXPORT_SYMBOL(_atomic_dec_and_lock);