linux-mips
[Top] [All Lists]

[PATCH 5/10] local_t : ia64

To: linux-kernel@vger.kernel.org, Andrew Morton <akpm@osdl.org>, Ingo Molnar <mingo@redhat.com>, Greg Kroah-Hartman <gregkh@suse.de>, Christoph Hellwig <hch@infradead.org>, Linux-MIPS <linux-mips@linux-mips.org>
Subject: [PATCH 5/10] local_t : ia64
From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Date: Wed, 20 Dec 2006 19:25:08 -0500
Cc: ltt-dev@shafik.org, systemtap@sources.redhat.com, Douglas Niehaus <niehaus@eecs.ku.edu>, "Martin J. Bligh" <mbligh@mbligh.org>, Thomas Gleixner <tglx@linutronix.de>
In-reply-to: <20061221001545.GP28643@Krystal>
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mutt/1.5.13 (2006-08-11)
ia64 architecture local_t extension.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

--- a/include/asm-mips/system.h
+++ b/include/asm-mips/system.h
@@ -253,6 +253,58 @@ static inline unsigned long __cmpxchg_u3
        return retval;
 }
 
+static inline unsigned long __cmpxchg_u32_local(volatile int * m,
+       unsigned long old, unsigned long new)
+{
+       __u32 retval;
+
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               __asm__ __volatile__(
+               "       .set    push                                    \n"
+               "       .set    noat                                    \n"
+               "       .set    mips3                                   \n"
+               "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
+               "       bne     %0, %z3, 2f                             \n"
+               "       .set    mips0                                   \n"
+               "       move    $1, %z4                                 \n"
+               "       .set    mips3                                   \n"
+               "       sc      $1, %1                                  \n"
+               "       beqzl   $1, 1b                                  \n"
+               "2:                                                     \n"
+               "       .set    pop                                     \n"
+               : "=&r" (retval), "=R" (*m)
+               : "R" (*m), "Jr" (old), "Jr" (new)
+               : "memory");
+       } else if (cpu_has_llsc) {
+               __asm__ __volatile__(
+               "       .set    push                                    \n"
+               "       .set    noat                                    \n"
+               "       .set    mips3                                   \n"
+               "1:     ll      %0, %2                  # __cmpxchg_u32 \n"
+               "       bne     %0, %z3, 2f                             \n"
+               "       .set    mips0                                   \n"
+               "       move    $1, %z4                                 \n"
+               "       .set    mips3                                   \n"
+               "       sc      $1, %1                                  \n"
+               "       beqz    $1, 1b                                  \n"
+               "2:                                                     \n"
+               "       .set    pop                                     \n"
+               : "=&r" (retval), "=R" (*m)
+               : "R" (*m), "Jr" (old), "Jr" (new)
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               retval = *m;
+               if (retval == old)
+                       *m = new;
+               local_irq_restore(flags);       /* implies memory barrier  */
+       }
+
+       return retval;
+}
+
 #ifdef CONFIG_64BIT
 static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
        unsigned long new)
@@ -303,10 +355,62 @@ static inline unsigned long __cmpxchg_u6
 
        return retval;
 }
+
+static inline unsigned long __cmpxchg_u64_local(volatile int * m,
+       unsigned long old, unsigned long new)
+{
+       __u64 retval;
+
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               __asm__ __volatile__(
+               "       .set    push                                    \n"
+               "       .set    noat                                    \n"
+               "       .set    mips3                                   \n"
+               "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
+               "       bne     %0, %z3, 2f                             \n"
+               "       move    $1, %z4                                 \n"
+               "       scd     $1, %1                                  \n"
+               "       beqzl   $1, 1b                                  \n"
+               "2:                                                     \n"
+               "       .set    pop                                     \n"
+               : "=&r" (retval), "=R" (*m)
+               : "R" (*m), "Jr" (old), "Jr" (new)
+               : "memory");
+       } else if (cpu_has_llsc) {
+               __asm__ __volatile__(
+               "       .set    push                                    \n"
+               "       .set    noat                                    \n"
+               "       .set    mips3                                   \n"
+               "1:     lld     %0, %2                  # __cmpxchg_u64 \n"
+               "       bne     %0, %z3, 2f                             \n"
+               "       move    $1, %z4                                 \n"
+               "       scd     $1, %1                                  \n"
+               "       beqz    $1, 1b                                  \n"
+               "2:                                                     \n"
+               "       .set    pop                                     \n"
+               : "=&r" (retval), "=R" (*m)
+               : "R" (*m), "Jr" (old), "Jr" (new)
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               retval = *m;
+               if (retval == old)
+                       *m = new;
+               local_irq_restore(flags);       /* implies memory barrier  */
+       }
+
+       return retval;
+}
+
 #else
 extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
        volatile int * m, unsigned long old, unsigned long new);
 #define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
+extern unsigned long __cmpxchg_u64_local_unsupported_on_32bit_kernels(
+       volatile int * m, unsigned long old, unsigned long new);
+#define __cmpxchg_u64_local __cmpxchg_u64_local_unsupported_on_32bit_kernels
 #endif
 
 /* This function doesn't exist, so you'll get a linker error
@@ -326,7 +430,26 @@ static inline unsigned long __cmpxchg(vo
        return old;
 }
 
-#define cmpxchg(ptr,old,new) ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned 
long)(old), (unsigned long)(new),sizeof(*(ptr))))
+static inline unsigned long __cmpxchg_local(volatile void * ptr,
+       unsigned long old, unsigned long new, int size)
+{
+       switch (size) {
+       case 4:
+               return __cmpxchg_u32_local(ptr, old, new);
+       case 8:
+               return __cmpxchg_u64_local(ptr, old, new);
+       }
+       __cmpxchg_called_with_bad_pointer();
+       return old;
+}
+
+#define cmpxchg(ptr,old,new) \
+       ((__typeof__(*(ptr)))__cmpxchg((ptr), \
+               (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
+
+#define cmpxchg_local(ptr,old,new) \
+       ((__typeof__(*(ptr)))__cmpxchg_local((ptr), \
+               (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
 
 extern void set_handler (unsigned long offset, void *addr, unsigned long len);
 extern void set_uncached_handler (unsigned long offset, void *addr, unsigned 
long len);
--- a/include/asm-mips/local.h
+++ b/include/asm-mips/local.h
@@ -1,60 +1,527 @@
-#ifndef _ASM_LOCAL_H
-#define _ASM_LOCAL_H
+#ifndef _ARCH_POWERPC_LOCAL_H
+#define _ARCH_POWERPC_LOCAL_H
 
 #include <linux/percpu.h>
 #include <asm/atomic.h>
 
-#ifdef CONFIG_32BIT
+typedef struct
+{
+       local_long_t a;
+} local_t;
 
-typedef atomic_t local_t;
+#define LOCAL_INIT(i)  { local_LONG_INIT(i) }
 
-#define LOCAL_INIT(i)  ATOMIC_INIT(i)
-#define local_read(v)  atomic_read(v)
-#define local_set(v,i) atomic_set(v,i)
+#define local_read(l)  local_long_read(&(l)->a)
+#define local_set(l,i) local_long_set(&(l)->a, (i))
 
-#define local_inc(v)   atomic_inc(v)
-#define local_dec(v)   atomic_dec(v)
-#define local_add(i, v)        atomic_add(i, v)
-#define local_sub(i, v)        atomic_sub(i, v)
+#define local_add(i,l) local_long_add((i),(&(l)->a))
+#define local_sub(i,l) local_long_sub((i),(&(l)->a))
+#define local_inc(l)   local_long_inc(&(l)->a)
+#define local_dec(l)   local_long_dec(&(l)->a)
 
-#endif
 
-#ifdef CONFIG_64BIT
+#ifndef CONFIG_64BITS
 
-typedef atomic64_t local_t;
+/*
+ * Same as above, but return the result value
+ */
+static __inline__ int local_add_return(int i, local_t * l)
+{
+       unsigned long result;
+
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     ll      %1, %2          # local_add_return      \n"
+               "       addu    %0, %1, %3                              \n"
+               "       sc      %0, %2                                  \n"
+               "       beqzl   %0, 1b                                  \n"
+               "       addu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else if (cpu_has_llsc) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     ll      %1, %2          # local_add_return      \n"
+               "       addu    %0, %1, %3                              \n"
+               "       sc      %0, %2                                  \n"
+               "       beqz    %0, 1b                                  \n"
+               "       addu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               result = &(l->a.counter);
+               result += i;
+               &(l->a.counter) = result;
+               local_irq_restore(flags);
+       }
+
+       return result;
+}
+
+static __inline__ int local_sub_return(int i, local_t * l)
+{
+       unsigned long result;
+
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     ll      %1, %2          # local_sub_return      \n"
+               "       subu    %0, %1, %3                              \n"
+               "       sc      %0, %2                                  \n"
+               "       beqzl   %0, 1b                                  \n"
+               "       subu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else if (cpu_has_llsc) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     ll      %1, %2          # local_sub_return      \n"
+               "       subu    %0, %1, %3                              \n"
+               "       sc      %0, %2                                  \n"
+               "       beqz    %0, 1b                                  \n"
+               "       subu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               result = &(l->a.counter);
+               result -= i;
+               &(l->a.counter) = result;
+               local_irq_restore(flags);
+       }
+
+       return result;
+}
+
+/*
+ * local_sub_if_positive - conditionally subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @l: pointer of type local_t
+ *
+ * Atomically test @l and subtract @i if @l is greater or equal than @i.
+ * The function returns the old value of @l minus @i.
+ */
+static __inline__ int local_sub_if_positive(int i, local_t * l)
+{
+       unsigned long result;
+
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     ll      %1, %2          # local_sub_if_positive\n"
+               "       subu    %0, %1, %3                              \n"
+               "       bltz    %0, 1f                                  \n"
+               "       sc      %0, %2                                  \n"
+               "       .set    noreorder                               \n"
+               "       beqzl   %0, 1b                                  \n"
+               "        subu   %0, %1, %3                              \n"
+               "       .set    reorder                                 \n"
+               "1:                                                     \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else if (cpu_has_llsc) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     ll      %1, %2          # local_sub_if_positive\n"
+               "       subu    %0, %1, %3                              \n"
+               "       bltz    %0, 1f                                  \n"
+               "       sc      %0, %2                                  \n"
+               "       .set    noreorder                               \n"
+               "       beqz    %0, 1b                                  \n"
+               "        subu   %0, %1, %3                              \n"
+               "       .set    reorder                                 \n"
+               "1:                                                     \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               result = &(l->a.counter);
+               result -= i;
+               if (result >= 0)
+                       &(l->a.counter) = result;
+               local_irq_restore(flags);
+       }
+
+       return result;
+}
+
+#define local_cmpxchg(l, o, n) \
+       ((long)cmpxchg(&((l)->a.counter), (o), (n)))
+#define local_xchg(l, new) (xchg(&((l)->a.counter), new))
+
+/**
+ * local_add_unless - add unless the number is a given value
+ * @l: pointer of type local_t
+ * @a: the amount to add to l...
+ * @u: ...unless l is equal to u.
+ *
+ * Atomically adds @a to @l, so long as it was not @u.
+ * Returns non-zero if @l was not @u, and zero otherwise.
+ */
+#define local_add_unless(l, a, u)                              \
+({                                                             \
+       long c, old;                                            \
+       c = local_read(l);                                      \
+       while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
+               c = old;                                        \
+       c != (u);                                               \
+})
+#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
+
+#define local_dec_return(l) local_sub_return(1,(l))
+#define local_inc_return(l) local_add_return(1,(l))
+
+/*
+ * local_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @l: pointer of type local_t
+ *
+ * Atomically subtracts @i from @l and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
+
+/*
+ * local_inc_and_test - increment and test
+ * @l: pointer of type local_t
+ *
+ * Atomically increments @l by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#define local_inc_and_test(l) (local_inc_return(l) == 0)
+
+/*
+ * local_dec_and_test - decrement by 1 and test
+ * @l: pointer of type local_t
+ *
+ * Atomically decrements @l by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
+
+/*
+ * local_dec_if_positive - decrement by 1 if old value positive
+ * @l: pointer of type local_t
+ */
+#define local_dec_if_positive(l)       local_sub_if_positive(1, l)
+
+/*
+ * local_add_negative - add and test if negative
+ * @l: pointer of type local_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @l and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+#define local_add_negative(i,l) (local_add_return(i, (l)) < 0)
+
+#else /* CONFIG_64BITS */
 
-#define LOCAL_INIT(i)  ATOMIC64_INIT(i)
-#define local_read(v)  atomic64_read(v)
-#define local_set(v,i) atomic64_set(v,i)
+/*
+ * Same as above, but return the result value
+ */
+static __inline__ long local_add_return(long i, local_t * l)
+{
+       unsigned long result;
+
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     lld     %1, %2          # local_add_return      \n"
+               "       addu    %0, %1, %3                              \n"
+               "       scd     %0, %2                                  \n"
+               "       beqzl   %0, 1b                                  \n"
+               "       addu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else if (cpu_has_llsc) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     lld     %1, %2          # local_add_return      \n"
+               "       addu    %0, %1, %3                              \n"
+               "       scd     %0, %2                                  \n"
+               "       beqz    %0, 1b                                  \n"
+               "       addu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               result = &(l->a.counter);
+               result += i;
+               &(l->a.counter) = result;
+               local_irq_restore(flags);
+       }
 
-#define local_inc(v)   atomic64_inc(v)
-#define local_dec(v)   atomic64_dec(v)
-#define local_add(i, v)        atomic64_add(i, v)
-#define local_sub(i, v)        atomic64_sub(i, v)
+       return result;
+}
 
-#endif
+static __inline__ long local_sub_return(long i, local_t * l)
+{
+       unsigned long result;
 
-#define __local_inc(v)         ((v)->counter++)
-#define __local_dec(v)         ((v)->counter--)
-#define __local_add(i,v)       ((v)->counter+=(i))
-#define __local_sub(i,v)       ((v)->counter-=(i))
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     lld     %1, %2          # local_sub_return      \n"
+               "       subu    %0, %1, %3                              \n"
+               "       scd     %0, %2                                  \n"
+               "       beqzl   %0, 1b                                  \n"
+               "       subu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else if (cpu_has_llsc) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     lld     %1, %2          # local_sub_return      \n"
+               "       subu    %0, %1, %3                              \n"
+               "       scd     %0, %2                                  \n"
+               "       beqz    %0, 1b                                  \n"
+               "       subu    %0, %1, %3                              \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               result = &(l->a.counter);
+               result -= i;
+               &(l->a.counter) = result;
+               local_irq_restore(flags);
+       }
+
+       return result;
+}
 
 /*
- * Use these for per-cpu local_t variables: on some archs they are
+ * local_sub_if_positive - conditionally subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @l: pointer of type local_t
+ *
+ * Atomically test @l and subtract @i if @l is greater or equal than @i.
+ * The function returns the old value of @l minus @i.
+ */
+static __inline__ long local_sub_if_positive(long i, local_t * l)
+{
+       unsigned long result;
+
+       if (cpu_has_llsc && R10000_LLSC_WAR) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     lld     %1, %2          # local_sub_if_positive\n"
+               "       dsubu   %0, %1, %3                              \n"
+               "       bltz    %0, 1f                                  \n"
+               "       scd     %0, %2                                  \n"
+               "       .set    noreorder                               \n"
+               "       beqzl   %0, 1b                                  \n"
+               "        dsubu  %0, %1, %3                              \n"
+               "       .set    reorder                                 \n"
+               "1:                                                     \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else if (cpu_has_llsc) {
+               unsigned long temp;
+
+               __asm__ __volatile__(
+               "       .set    mips3                                   \n"
+               "1:     lld     %1, %2          # local_sub_if_positive\n"
+               "       dsubu   %0, %1, %3                              \n"
+               "       bltz    %0, 1f                                  \n"
+               "       scd     %0, %2                                  \n"
+               "       .set    noreorder                               \n"
+               "       beqz    %0, 1b                                  \n"
+               "        dsubu  %0, %1, %3                              \n"
+               "       .set    reorder                                 \n"
+               "1:                                                     \n"
+               "       .set    mips0                                   \n"
+               : "=&r" (result), "=&r" (temp), "=m" (&(l->a.counter))
+               : "Ir" (i), "m" (&(l->a.counter))
+               : "memory");
+       } else {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               result = &(l->a.counter);
+               result -= i;
+               if (result >= 0)
+                       &(l->a.counter) = result;
+               local_irq_restore(flags);
+       }
+
+       return result;
+}
+
+
+#define local_cmpxchg(l, o, n) \
+       ((long)cmpxchg(&((l)->a.counter), (o), (n)))
+#define local_xchg(l, new) (xchg(&((l)->a.counter), new))
+
+/**
+ * local_add_unless - add unless the number is a given value
+ * @l: pointer of type local_t
+ * @a: the amount to add to l...
+ * @u: ...unless l is equal to u.
+ *
+ * Atomically adds @a to @l, so long as it was not @u.
+ * Returns non-zero if @l was not @u, and zero otherwise.
+ */
+#define local_add_unless(l, a, u)                              \
+({                                                             \
+       long c, old;                                            \
+       c = local_read(l);                                      \
+       while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
+               c = old;                                        \
+       c != (u);                                               \
+})
+#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
+
+#define local_dec_return(l) local_sub_return(1,(l))
+#define local_inc_return(l) local_add_return(1,(l))
+
+/*
+ * local_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @l: pointer of type local_t
+ *
+ * Atomically subtracts @i from @l and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
+
+/*
+ * local_inc_and_test - increment and test
+ * @l: pointer of type local_t
+ *
+ * Atomically increments @l by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#define local_inc_and_test(l) (local_inc_return(l) == 0)
+
+/*
+ * local_dec_and_test - decrement by 1 and test
+ * @l: pointer of type local_t
+ *
+ * Atomically decrements @l by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
+
+/*
+ * local_dec_if_positive - decrement by 1 if old value positive
+ * @l: pointer of type local_t
+ */
+#define local_dec_if_positive(l)       local_sub_if_positive(1, l)
+
+/*
+ * local_add_negative - add and test if negative
+ * @l: pointer of type local_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @l and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+#define local_add_negative(i,l) (local_add_return(i, (l)) < 0)
+
+#endif /* !CONFIG_64BITS */
+
+
+/* Use these for per-cpu local_t variables: on some archs they are
  * much more efficient than these naive implementations.  Note they take
  * a variable, not an address.
+ *
+ * This could be done better if we moved the per cpu data directly
+ * after GS.
  */
-#define cpu_local_read(v)      local_read(&__get_cpu_var(v))
-#define cpu_local_set(v, i)    local_set(&__get_cpu_var(v), (i))
 
-#define cpu_local_inc(v)       local_inc(&__get_cpu_var(v))
-#define cpu_local_dec(v)       local_dec(&__get_cpu_var(v))
-#define cpu_local_add(i, v)    local_add((i), &__get_cpu_var(v))
-#define cpu_local_sub(i, v)    local_sub((i), &__get_cpu_var(v))
+#define __local_inc(l)         ((l)->a.counter++)
+#define __local_dec(l)         ((l)->a.counter++)
+#define __local_add(i,l)       ((l)->a.counter+=(i))
+#define __local_sub(i,l)       ((l)->a.counter-=(i))
+
+/* Need to disable preemption for the cpu local counters otherwise we could
+   still access a variable of a previous CPU in a non atomic way. */
+#define cpu_local_wrap_v(l)            \
+       ({ local_t res__;               \
+          preempt_disable();           \
+          res__ = (l);                 \
+          preempt_enable();            \
+          res__; })
+#define cpu_local_wrap(l)              \
+       ({ preempt_disable();           \
+          l;                           \
+          preempt_enable(); })         \
+
+#define cpu_local_read(l)    cpu_local_wrap_v(local_read(&__get_cpu_var(l)))
+#define cpu_local_set(l, i)  cpu_local_wrap(local_set(&__get_cpu_var(l), (i)))
+#define cpu_local_inc(l)     cpu_local_wrap(local_inc(&__get_cpu_var(l)))
+#define cpu_local_dec(l)     cpu_local_wrap(local_dec(&__get_cpu_var(l)))
+#define cpu_local_add(i, l)  cpu_local_wrap(local_add((i), &__get_cpu_var(l)))
+#define cpu_local_sub(i, l)  cpu_local_wrap(local_sub((i), &__get_cpu_var(l)))
 
-#define __cpu_local_inc(v)     __local_inc(&__get_cpu_var(v))
-#define __cpu_local_dec(v)     __local_dec(&__get_cpu_var(v))
-#define __cpu_local_add(i, v)  __local_add((i), &__get_cpu_var(v))
-#define __cpu_local_sub(i, v)  __local_sub((i), &__get_cpu_var(v))
+#define __cpu_local_inc(l)     cpu_local_inc(l)
+#define __cpu_local_dec(l)     cpu_local_dec(l)
+#define __cpu_local_add(i, l)  cpu_local_add((i), (l))
+#define __cpu_local_sub(i, l)  cpu_local_sub((i), (l))
 
-#endif /* _ASM_LOCAL_H */
+#endif /* _ARCH_POWERPC_LOCAL_H */

OpenPGP public key:              http://krystal.dyndns.org:8080/key/compudj.gpg
Key fingerprint:     8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68 

<Prev in Thread] Current Thread [Next in Thread>