X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Farm7%2Finclude%2Flock.h;h=627726b568f7f009125e6d697616016f2bd6ecd6;hb=17aac974ab83a3521f2b49b8de33ae05a00fbe07;hp=9b289d137fd859f1f34155bc37d8278581dc68bc;hpb=e4ccf568b07857a36382433ed73ea38874843b24;p=tpg%2Facess2.git

diff --git a/Kernel/arch/arm7/include/lock.h b/Kernel/arch/arm7/include/lock.h
index 9b289d13..627726b5 100644
--- a/Kernel/arch/arm7/include/lock.h
+++ b/Kernel/arch/arm7/include/lock.h
@@ -26,18 +26,28 @@ static inline int CPU_HAS_LOCK(struct sShortSpinlock *Lock)
 
 static inline int SHORTLOCK(struct sShortSpinlock *Lock)
 {
-	// Shamelessly copied from linux (/arch/arm/include/asm/spinlock.h) until I can fix stuff
+	#if 1
+	// Coped from linux, yes, but I know what it does now :)
 	Uint	tmp;
 	__asm__ __volatile__ (
-	"1:	ldrex	%0, [%1]\n"
-	"	teq	%0, #0\n"
-	"	strexeq %0, %2, [%1]\n"	// Magic? TODO: Look up
-	"	teqeq	%0, #0\n"
-	"	bne	1b"
+	"1:	ldrex	%0, [%1]\n"	// Exclusive LOAD
+	"	teq	%0, #0\n"	// Check if zero
+	"	strexeq %0, %2, [%1]\n"	// Set to one if it is zero (releasing lock on the memory)
+	"	teqeq	%0, #0\n"	// If the lock was avaliable, check if the write succeeded
+	"	bne	1b"	// If the lock was unavaliable, or the write failed, loop
 		: "=&r" (tmp)	// Temp
 		: "r" (&Lock->Lock), "r" (1)
 		: "cc"	// Condition codes clobbered
 		);
+	#else
+	 int	v = 1;
+	while( v )
+		__asm__ __volatile__ (
+			"swp %0, [%1]"
+			: "=r" (v) : "r" (&Lock->Lock)
+			: "cc"
+			);
+	#endif
 	return 1;
 }