commit 683a77455f2226419fe688dd2104ef1a391bb3b2
Author: Sergei Poselenov <[email protected]>
Date: Sun Oct 26 14:54:12 2014 +0400
Implemented testandset() for Cortex-M3
Signed-off-by: Sergei Poselenov <[email protected]>
diff --git a/extra/Configs/Config.arm b/extra/Configs/Config.arm
index 0bb2971..5777d3b 100644
--- a/extra/Configs/Config.arm
+++ b/extra/Configs/Config.arm
@@ -36,3 +36,10 @@ config USE_BX
Say 'y' to use BX to return from functions on your thumb-aware
processor. Say 'y' if you need to use interworking. Say 'n' if not.
It is safe to say 'y' even if you're not doing interworking.
+
+config USE_LDREXSTREX
+ bool "Use load-store exclusive ASM ops (not supported in SmartFusion)"
+ depends on COMPILE_IN_THUMB_MODE
+ default y
+ help
+ Say 'y' to use LDREX/STREX ASM ops.
diff --git a/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h
b/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h
index 583eb68..93804ba 100644
--- a/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h
+++ b/libpthread/linuxthreads.old/sysdeps/arm/pt-machine.h
@@ -22,12 +22,50 @@
#ifndef _PT_MACHINE_H
#define _PT_MACHINE_H 1
-#include <features.h>
+#include <sys/syscall.h>
+#include <unistd.h>
#ifndef PT_EI
# define PT_EI __extern_always_inline
#endif
+#if defined(__thumb__)
+#if defined(__USE_LDREXSTREX__)
+PT_EI long int ldrex(int *spinlock)
+{
+ long int ret;
+ __asm__ __volatile__(
+ "ldrex %0, [%1]\n"
+ : "=r"(ret)
+ : "r"(spinlock) : "memory");
+ return ret;
+}
+
+PT_EI long int strex(int val, int *spinlock)
+{
+ long int ret;
+ __asm__ __volatile__(
+ "strex %0, %1, [%2]\n"
+ : "=r"(ret)
+ : "r" (val), "r"(spinlock) : "memory");
+ return ret;
+}
+
+/* Spinlock implementation; required. */
+PT_EI long int
+testandset (int *spinlock)
+{
+ register unsigned int ret;
+
+ do {
+ ret = ldrex(spinlock);
+ } while (strex(1, spinlock));
+
+ return ret;
+}
+
+#else /* __USE_LDREXSTREX__ */
+
/* This will not work on ARM1 or ARM2 because SWP is lacking on those
machines. Unfortunately we have no way to detect this at compile
time; let's hope nobody tries to use one. */
@@ -37,8 +75,6 @@ PT_EI long int testandset (int *spinlock);
PT_EI long int testandset (int *spinlock)
{
register unsigned int ret;
-
-#if defined(__thumb__)
void *pc;
__asm__ __volatile__(
".align 0\n"
@@ -51,15 +87,21 @@ PT_EI long int testandset (int *spinlock)
"\t.force_thumb"
: "=r"(ret), "=r"(pc)
: "0"(1), "r"(spinlock));
-#else
+ return ret;
+}
+#endif
+#else /* __thumb__ */
+
+PT_EI long int testandset (int *spinlock);
+PT_EI long int testandset (int *spinlock)
+{
+ register unsigned int ret;
__asm__ __volatile__("swp %0, %1, [%2]"
: "=r"(ret)
: "0"(1), "r"(spinlock));
-#endif
-
return ret;
}
-
+#endif
/* Get some notion of the current stack. Need not be exactly the top
of the stack, just something somewhere in the current frame. */
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