Import sources from 2011-03-30 iso image

1 files changed, 169 insertions, 0 deletions

diff --git a/sys/src/libc/mips/lock.c b/sys/src/libc/mips/lock.c
new file mode 100755
index 000000000..c42208822
--- /dev/null
+++ b/sys/src/libc/mips/lock.c
@@ -0,0 +1,169 @@
+#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;
+			}
+		}
+		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;
+			}
+		}
+		return 1;
+	}
+}