libc: change tas/sleep locks to cas/semacquire/semrelease locks (from sources)

spinlocks have been changed to use the new semacquire/semrelease
syscalls in combination with atomic compare and swap operations.

4 files changed, 5 insertions, 181 deletions

diff --git a/sys/src/libc/mips/atom.s b/sys/src/libc/mips/atom.s
index 8975ac569..b907f7f59 100644
--- a/sys/src/libc/mips/atom.s
+++ b/sys/src/libc/mips/atom.s
@@ -12,7 +12,8 @@ TEXT _xinc(SB), 1, $-4			/* void _xinc(long *); */
 loop:	MOVW	$1, R3
 	LL(2, 1)
 	NOOP
-	ADD	R1,R3,R3
+	ADDU	R1, R3
+	MOVW	R3, R1			/* return new value */
 	SC(2, 3)
 	NOOP
 	BEQ	R3,loop
@@ -24,8 +25,8 @@ TEXT _xdec(SB), 1, $-4			/* long _xdec(long *); */
 loop1:	MOVW	$-1, R3
 	LL(2, 1)
 	NOOP
-	ADD	R1,R3,R3
-	MOVW	R3, R1
+	ADDU	R1, R3
+	MOVW	R3, R1			/* return new value */
 	SC(2, 3)
 	NOOP
 	BEQ	R3,loop1
@@ -49,9 +50,3 @@ spincas:
 fail:
 	MOVW	$0, R1
 	RET
-
-/* general-purpose abort */
-_trap:
-	MOVD	$0, R0
-	MOVD	0(R0), R0
-	RET
diff --git a/sys/src/libc/mips/lock.c b/sys/src/libc/mips/lock.c
deleted file mode 100644
index 9c9bd2208..000000000
--- a/sys/src/libc/mips/lock.c
+++ /dev/null
@@ -1,171 +0,0 @@
-#include <u.h>
-#include <libc.h>
-
-enum
-{
-	Pagesize	= 4096,
-	Semperpg	= Pagesize/(16*sizeof(uint)),
-	Lockaddr	= 0x60000000,
-
-	POWER		= 0x320,
-	MAGNUM		= 0x330,
-	MAGNUMII	= 0x340,
-	R4K		= 0x500,
-};
-
-static	int arch;
-extern	int C_3ktas(int*);
-extern	int C_4ktas(int*);
-extern	int C_fcr0(void);
-
-static void
-lockinit(void)
-{
-	void *v;
-
-	if(arch != 0)
-		return;	/* allow multiple calls */
-	arch = C_fcr0();
-	switch(arch) {
-	case POWER:
-		v = (void*)Lockaddr;
-		if(segattach(SG_CEXEC, "lock", v, Pagesize) == (void*)-1) {
-			arch = MAGNUM;
-			break;
-		}
-		memset(v, 0, Pagesize);
-		break;
-	case MAGNUM:
-	case MAGNUMII:
-	case R4K:
-		break;
-	default:
-		arch = R4K;
-		break;
-	}
-}
-
-void
-lock(Lock *lk)
-{
-	int *hwsem;
-	int hash;
-
-retry:
-	switch(arch) {
-	case 0:
-		lockinit();
-		goto retry;
-	case MAGNUM:
-	case MAGNUMII:
-		while(C_3ktas(&lk->val))
-			sleep(0);
-		return;
-	case R4K:
-		for(;;){
-			while(lk->val)
-				;
-			if(C_4ktas(&lk->val) == 0)
-				return;
-		}
-		break;
-	case POWER:
-		/* Use low order lock bits to generate hash */
-		hash = ((int)lk/sizeof(int)) & (Semperpg-1);
-		hwsem = (int*)Lockaddr+hash;
-
-		for(;;) {
-			if((*hwsem & 1) == 0) {
-				if(lk->val)
-					*hwsem = 0;
-				else {
-					lk->val = 1;
-					*hwsem = 0;
-					return;
-				}
-			}
-			while(lk->val)
-				;
-		}
-	}
-}
-
-int
-canlock(Lock *lk)
-{
-	int *hwsem;
-	int hash;
-
-retry:
-	switch(arch) {
-	case 0:
-		lockinit();
-		goto retry;
-	case MAGNUM:
-	case MAGNUMII:
-		if(C_3ktas(&lk->val))
-			return 0;
-		return 1;
-	case R4K:
-		if(C_4ktas(&lk->val))
-			return 0;
-		return 1;
-	case POWER:
-		/* Use low order lock bits to generate hash */
-		hash = ((int)lk/sizeof(int)) & (Semperpg-1);
-		hwsem = (int*)Lockaddr+hash;
-
-		if((*hwsem & 1) == 0) {
-			if(lk->val)
-				*hwsem = 0;
-			else {
-				lk->val = 1;
-				*hwsem = 0;
-				return 1;
-			}
-		}
-		break;
-	}
-	return 0;
-}
-
-void
-unlock(Lock *lk)
-{
-	lk->val = 0;
-}
-
-int
-_tas(int *p)
-{
-	int *hwsem;
-	int hash;
-
-retry:
-	switch(arch) {
-	case 0:
-		lockinit();
-		goto retry;
-	case MAGNUM:
-	case MAGNUMII:
-		return C_3ktas(p);
-	case R4K:
-		return C_4ktas(p);
-	case POWER:
-		/* Use low order lock bits to generate hash */
-		hash = ((int)p/sizeof(int)) & (Semperpg-1);
-		hwsem = (int*)Lockaddr+hash;
-
-		if((*hwsem & 1) == 0) {
-			if(*p)
-				*hwsem = 0;
-			else {
-				*p = 1;
-				*hwsem = 0;
-				return 0;
-			}
-		}
-		break;
-	}
-	return 1;
-}
diff --git a/sys/src/libc/mips/mkfile b/sys/src/libc/mips/mkfile
index 3b902f6e3..460f7cd2f 100644
--- a/sys/src/libc/mips/mkfile
+++ b/sys/src/libc/mips/mkfile
@@ -23,7 +23,6 @@ SFILES=\
 
 CFILES=\
 	cycles.c\
-	lock.c\
 	notejmp.c\
 	sqrt.c\
 	vlrt.c\
diff --git a/sys/src/libc/mips/tas.s b/sys/src/libc/mips/tas.s
index d754b21f6..a9bf40721 100644
--- a/sys/src/libc/mips/tas.s
+++ b/sys/src/libc/mips/tas.s
@@ -17,6 +17,7 @@ btas:
 	BLTZ	R1, btas
 	RET
 
+	TEXT	_tas(SB),$0
 	TEXT	C_4ktas(SB), $0
 	MOVW	R1, R2		/* address of key */
 tas1: