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authorOlof Johansson <olof@lixom.net>2013-08-29 19:12:04 -0700
committerOlof Johansson <olof@lixom.net>2013-08-29 19:12:04 -0700
commit2bbc31ef2b398d17016c6438016cc76913990950 (patch)
tree10de572013948341054d73acfab0f6d77ae35cbd /arch/alpha/include/asm/atomic.h
parenta3e008d1b5e39abe81e233bde623604841ff9a73 (diff)
parentaf0721966195b3966214edd54af0d5f84d65419a (diff)
downloadop-kernel-dev-2bbc31ef2b398d17016c6438016cc76913990950.zip
op-kernel-dev-2bbc31ef2b398d17016c6438016cc76913990950.tar.gz
Merge tag 'omap-for-v3.12/fixes-non-critical-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/fixes-non-critical
From Tony Lindgren: Omap fixes for the merge window that are not urgent enough for the -rc series. * tag 'omap-for-v3.12/fixes-non-critical-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: ARM: OMAP2: use 'int' instead of 'unsigned' for variable 'gpmc_irq_start' ARM: OMAP2: remove useless variable 'ret' ARM: OMAP: dma: fix error return code in omap_system_dma_probe() ARM: OMAP2+: fix wrong address when loading PRM_FRAC_INCREMENTOR_DENUMERATOR_RELOAD ARM: OMAP2+: am33xx-restart: trigger warm reset on omap2+ boards ARM: OMAP2: Use a consistent AM33XX SoC option description ARM: OMAP2+: Remove legacy device creation for McPDM and DMIC + Linux 3.11-rc6
Diffstat (limited to 'arch/alpha/include/asm/atomic.h')
-rw-r--r--arch/alpha/include/asm/atomic.h88
1 files changed, 65 insertions, 23 deletions
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
index c2cbe4f..78b03ef 100644
--- a/arch/alpha/include/asm/atomic.h
+++ b/arch/alpha/include/asm/atomic.h
@@ -186,17 +186,24 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
*/
static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
{
- int c, old;
- c = atomic_read(v);
- for (;;) {
- if (unlikely(c == (u)))
- break;
- old = atomic_cmpxchg((v), c, c + (a));
- if (likely(old == c))
- break;
- c = old;
- }
- return c;
+ int c, new, old;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldl_l %[old],%[mem]\n"
+ " cmpeq %[old],%[u],%[c]\n"
+ " addl %[old],%[a],%[new]\n"
+ " bne %[c],2f\n"
+ " stl_c %[new],%[mem]\n"
+ " beq %[new],3f\n"
+ "2:\n"
+ ".subsection 2\n"
+ "3: br 1b\n"
+ ".previous"
+ : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
+ : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
+ : "memory");
+ smp_mb();
+ return old;
}
@@ -207,21 +214,56 @@ static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
- * Returns the old value of @v.
+ * Returns true iff @v was not @u.
*/
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
{
- long c, old;
- c = atomic64_read(v);
- for (;;) {
- if (unlikely(c == (u)))
- break;
- old = atomic64_cmpxchg((v), c, c + (a));
- if (likely(old == c))
- break;
- c = old;
- }
- return c != (u);
+ long c, tmp;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldq_l %[tmp],%[mem]\n"
+ " cmpeq %[tmp],%[u],%[c]\n"
+ " addq %[tmp],%[a],%[tmp]\n"
+ " bne %[c],2f\n"
+ " stq_c %[tmp],%[mem]\n"
+ " beq %[tmp],3f\n"
+ "2:\n"
+ ".subsection 2\n"
+ "3: br 1b\n"
+ ".previous"
+ : [tmp] "=&r"(tmp), [c] "=&r"(c)
+ : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
+ : "memory");
+ smp_mb();
+ return !c;
+}
+
+/*
+ * atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
+ */
+static inline long atomic64_dec_if_positive(atomic64_t *v)
+{
+ long old, tmp;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldq_l %[old],%[mem]\n"
+ " subq %[old],1,%[tmp]\n"
+ " ble %[old],2f\n"
+ " stq_c %[tmp],%[mem]\n"
+ " beq %[tmp],3f\n"
+ "2:\n"
+ ".subsection 2\n"
+ "3: br 1b\n"
+ ".previous"
+ : [old] "=&r"(old), [tmp] "=&r"(tmp)
+ : [mem] "m"(*v)
+ : "memory");
+ smp_mb();
+ return old - 1;
}
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
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