[CRIU] [PATCH] arm: fix compilation on ARMv6

[Andrew Vagin]

On Mon, Dec 22, 2014 at 01:25:32PM +0200, Ruslan Kuprieiev wrote:
> 
> 
> 22.12.2014 13:16, Andrew Vagin пишет:
> >Cc: Ruslan Kuprieiev <kupruser at gmail.com>
> >Signed-off-by: Andrew Vagin <avagin at openvz.org>
> >---
> >  arch/arm/include/asm/atomic.h |   61 +++++++++++++++++++++++++----------------
> >  1 file changed, 37 insertions(+), 24 deletions(-)
> >
> >diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
> >index 04faf58..cd0df37 100644
> >--- a/arch/arm/include/asm/atomic.h
> >+++ b/arch/arm/include/asm/atomic.h
> >@@ -14,10 +14,47 @@ typedef struct {
> >
> >  #define smp_mb() __asm__ __volatile__ ("dmb" : : : "memory")
> >
> >+static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
> >+{
> >+	int oldval;
> >+	unsigned long res;
> >+
> >+	smp_mb();
> >+	prefetchw(&ptr->counter);
> >+
> >+	do {
> >+		__asm__ __volatile__("@ atomic_cmpxchg\n"
> >+		"ldrex	%1, [%3]\n"
> >+		"mov	%0, #0\n"
> >+		"teq	%1, %4\n"
> >+		"strexeq %0, %5, [%3]\n"
> >+		    : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter)
> >+		    : "r" (&ptr->counter), "Ir" (old), "r" (new)
> >+		    : "cc");
> >+	} while (res);
> >+
> >+	smp_mb();
> >+
> >+	return oldval;
> >+}
> >+
> >  #elif defined(CONFIG_ARMV6)
> >
> >+/* SMP isn't supported for ARMv6 */
> >+
> >  #define smp_mb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5"	: : "r" (0) : "memory")
> >
> >+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
> >+{
> >+        int ret;
> >+
> >+        ret = v->counter;
> >+        if (ret == old)
> >+                v->counter = new;
> >+
> 
> I have a better one with raw_local_irq_*. =)

Are you going to block signals? I don't think that it's required here.

> I will send it ASAP.
> 
> >+        return ret;
> >+}
> >+
> >  #else
> >
> >  #error ARM architecture version (CONFIG_ARMV*) not set or unsupported.
> >@@ -91,28 +128,4 @@ static inline int atomic_dec(atomic_t *v) { return atomic_sub_return(1, v) + 1;
> >
> >  #define atomic_inc_return(v)	(atomic_add_return(1, v))
> >
> >-static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
> >-{
> >-	int oldval;
> >-	unsigned long res;
> >-
> >-	smp_mb();
> >-	prefetchw(&ptr->counter);
> >-
> >-	do {
> >-		__asm__ __volatile__("@ atomic_cmpxchg\n"
> >-		"ldrex	%1, [%3]\n"
> >-		"mov	%0, #0\n"
> >-		"teq	%1, %4\n"
> >-		"strexeq %0, %5, [%3]\n"
> >-		    : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter)
> >-		    : "r" (&ptr->counter), "Ir" (old), "r" (new)
> >-		    : "cc");
> >-	} while (res);
> >-
> >-	smp_mb();
> >-
> >-	return oldval;
> >-}
> >-
> >  #endif /* __CR_ATOMIC_H__ */
> >