kernel: do all fp state fork from procfork() (like pc kernel)

this simplifies the arm ports and keeps all the stuff in one place
instead of spreading it thru notify(), trap() and syscall() functions
and prevents useless fp state copying for kernel procs.

also make sure to save fp in notify while still splhi().

sys/src/9/alphapc/trap.c

@@ -523,16 +523,16 @@ notify(Ureg *ur)
 	if(up->nnote == 0)
 		return 0;
 
-	spllo();
-	qlock(&up->debug);
-	up->notepending = 0;
-
 	if(up->fpstate == FPactive){
 		savefpregs(&up->fpsave);
 		up->fpstate = FPinactive;
 	}
 	up->fpstate |= FPillegal;
 
+	spllo();
+	qlock(&up->debug);
+	up->notepending = 0;
+
 	n = &up->note[0];
 	if(strncmp(n->msg, "sys:", 4) == 0) {
 		l = strlen(n->msg);
@@ -712,12 +712,6 @@ syscall(Ureg *aur)
 
 	scallnr = ur->r0;
 	up->scallnr = ur->r0;
-
-	if(scallnr == RFORK && up->fpstate == FPactive){
-		savefpregs(&up->fpsave);
-		up->fpstate = FPinactive;
-//print("SR=%lux+", up->fpsave.fpstatus);
-	}
 	spllo();
 
 	sp = ur->sp;

sys/src/9/bcm/fns.h

@@ -82,9 +82,8 @@ extern void fpunoted(void);
 extern void fpunotify(Ureg*);
 extern void fpuprocrestore(Proc*);
 extern void fpuprocsave(Proc*);
+extern void fpuprocfork(Proc*);
 extern void fpusysprocsetup(Proc*);
-extern void fpusysrfork(Ureg*);
-extern void fpusysrforkchild(Proc*, Ureg*, Proc*);
 extern int fpuemu(Ureg*);
 /*
  * Things called from port.

sys/src/9/bcm/vfp3.c

@@ -239,33 +239,6 @@ fpunoted(void)
 	up->fpstate &= ~FPillegal;
 }
 
-/*
- * Called early in the non-interruptible path of
- * sysrfork() via the machine-dependent syscall() routine.
- * Save the state so that it can be easily copied
- * to the child process later.
- */
-void
-fpusysrfork(Ureg*)
-{
-	if(up->fpstate == FPactive){
-		fpsave(&up->fpsave);
-		up->fpstate = FPinactive;
-	}
-}
-
-/*
- * Called later in sysrfork() via the machine-dependent
- * sysrforkchild() routine.
- * Copy the parent FPU state to the child.
- */
-void
-fpusysrforkchild(Proc *p, Ureg *, Proc *up)
-{
-	/* don't penalize the child, it hasn't done FP in a note handler. */
-	p->fpstate = up->fpstate & ~FPillegal;
-}
-
 /* should only be called if p->fpstate == FPactive */
 void
 fpsave(FPsave *fps)
@@ -332,6 +305,28 @@ fpuprocrestore(Proc *)
 {
 }
 
+/*
+ * The current process has been forked,
+ * save and copy neccesary state to child.
+ */
+void
+fpuprocfork(Proc *p)
+{
+	int s;
+
+	s = splhi();
+	switch(up->fpstate & ~FPillegal){
+	case FPactive:
+		fpsave(&up->fpsave);
+		up->fpstate = FPinactive;
+		/* no break */
+	case FPinactive:
+		p->fpsave = up->fpsave;
+		p->fpstate = FPinactive;
+	}
+	splx(s);
+}
+
 /*
  * Disable the FPU.
  * Called from sysexec() via sysprocsetup() to

sys/src/9/kw/fns.h

@@ -99,8 +99,6 @@ extern void fpunotify(Ureg*);
 extern void fpuprocrestore(Proc*);
 extern void fpuprocsave(Proc*);
 extern void fpusysprocsetup(Proc*);
-extern void fpusysrfork(Ureg*);
-extern void fpusysrforkchild(Proc*, Ureg *, Proc*);
 extern int fpuemu(Ureg*);
 
 /*

sys/src/9/kw/softfpu.c

@@ -41,27 +41,6 @@ fpunoted(void)
 	 */
 }
 
-void
-fpusysrfork(Ureg*)
-{
-	/*
-	 * Called early in the non-interruptible path of
-	 * sysrfork() via the machine-dependent syscall() routine.
-	 * Save the state so that it can be easily copied
-	 * to the child process later.
-	 */
-}
-
-void
-fpusysrforkchild(Proc*, Ureg*, Proc*)
-{
-	/*
-	 * Called later in sysrfork() via the machine-dependent
-	 * sysrforkchild() routine.
-	 * Copy the parent FPU state to the child.
-	 */
-}
-
 void
 fpuprocsave(Proc*)
 {

sys/src/9/kw/syscall.c

@@ -201,8 +201,6 @@ syscall(Ureg* ureg)
 
 	scallnr = ureg->r0;
 	up->scallnr = scallnr;
-	if(scallnr == RFORK)
-		fpusysrfork(ureg);
 	spllo();
 	sp = ureg->sp;
 
@@ -332,6 +330,4 @@ forkchild(Proc *p, Ureg *ureg)
 	/* Things from bottom of syscall which were never executed */
 	p->psstate = 0;
 	p->insyscall = 0;
-
-	fpusysrforkchild(p, cureg, up);
 }

sys/src/9/omap/arch.c

@@ -134,6 +134,8 @@ procfork(Proc* p)
 {
 	p->kentry = up->kentry;
 	p->pcycles = -p->kentry;
+
+	fpuprocfork(p);
 }
 
 /*

sys/src/9/omap/fns.h

@@ -114,8 +114,7 @@ extern void fpunotify(Ureg*);
 extern void fpuprocrestore(Proc*);
 extern void fpuprocsave(Proc*);
 extern void fpusysprocsetup(Proc*);
-extern void fpusysrfork(Ureg*);
-extern void fpusysrforkchild(Proc*, Ureg*, Proc*);
+extern void fpuprocfork(Proc*);
 extern int fpuemu(Ureg*);
 
 /*

sys/src/9/omap/softfpu.c

@@ -41,27 +41,6 @@ fpunoted(void)
 	 */
 }
 
-void
-fpusysrfork(Ureg*)
-{
-	/*
-	 * Called early in the non-interruptible path of
-	 * sysrfork() via the machine-dependent syscall() routine.
-	 * Save the state so that it can be easily copied
-	 * to the child process later.
-	 */
-}
-
-void
-fpusysrforkchild(Proc*, Ureg *, Proc*)
-{
-	/*
-	 * Called later in sysrfork() via the machine-dependent
-	 * sysrforkchild() routine.
-	 * Copy the parent FPU state to the child.
-	 */
-}
-
 void
 fpuprocsave(Proc*)
 {
@@ -85,6 +64,15 @@ fpuprocrestore(Proc*)
 	 */
 }
 
+void
+fpuprocfork(Proc*)
+{
+	/*
+	 * The current process has been forked, save and copy neccesary
+	 * state to child. Nothing to do here, child proc starts with FPinit.
+	 */
+}
+
 void
 fpusysprocsetup(Proc*)
 {

sys/src/9/omap/syscall.c

@@ -205,8 +205,6 @@ syscall(Ureg* ureg)
 
 	scallnr = ureg->r0;
 	up->scallnr = scallnr;
-	if(scallnr == RFORK)
-		fpusysrfork(ureg);
 	spllo();
 
 	sp = ureg->sp;
@@ -328,6 +326,4 @@ forkchild(Proc *p, Ureg *ureg)
 	/* Things from bottom of syscall which were never executed */
 	p->psstate = 0;
 	p->insyscall = 0;
-
-	fpusysrforkchild(p, cureg, up);
 }

sys/src/9/ppc/trap.c

@@ -633,10 +633,6 @@ syscall(Ureg* ureg)
 
 	scallnr = ureg->r3;
 	up->scallnr = ureg->r3;
-	if(scallnr == RFORK && up->fpstate == FPactive){
-		fpsave(&up->fpsave);
-		up->fpstate = FPinactive;
-	}
 	spllo();
 
 	sp = ureg->usp;
@@ -714,6 +710,12 @@ notify(Ureg* ur)
 	if(up->nnote == 0)
 		return 0;
 
+	if(up->fpstate == FPactive){
+		fpsave(&up->fpsave);
+		up->fpstate = FPinactive;
+	}
+	up->fpstate |= FPillegal;
+
 	s = spllo();
 	qlock(&up->debug);
 	up->notepending = 0;
@@ -743,12 +745,6 @@ notify(Ureg* ur)
 		pexit(n->msg, n->flag!=NDebug);
 	}
 
-	if(up->fpstate == FPactive){
-		fpsave(&up->fpsave);
-		up->fpstate = FPinactive;
-	}
-	up->fpstate |= FPillegal;
-
 	sp = ur->usp & ~(BY2V-1);
 	sp -= sizeof(Ureg);
 

sys/src/9/teg2/fns.h

@@ -172,8 +172,6 @@ extern void fpunotify(Ureg*);
 extern void fpuprocrestore(Proc*);
 extern void fpuprocsave(Proc*);
 extern void fpusysprocsetup(Proc*);
-extern void fpusysrfork(Ureg*);
-extern void fpusysrforkchild(Proc*, Ureg*, Proc*);
 extern int fpuemu(Ureg*);
 
 /*

sys/src/9/teg2/softfpu.c

@@ -41,27 +41,6 @@ fpunoted(void)
 	 */
 }
 
-void
-fpusysrfork(Ureg*)
-{
-	/*
-	 * Called early in the non-interruptible path of
-	 * sysrfork() via the machine-dependent syscall() routine.
-	 * Save the state so that it can be easily copied
-	 * to the child process later.
-	 */
-}
-
-void
-fpusysrforkchild(Proc*, Ureg *, Proc*)
-{
-	/*
-	 * Called later in sysrfork() via the machine-dependent
-	 * sysrforkchild() routine.
-	 * Copy the parent FPU state to the child.
-	 */
-}
-
 void
 fpuprocsave(Proc*)
 {

sys/src/9/teg2/syscall.c

@@ -209,8 +209,6 @@ syscall(Ureg* ureg)
 
 	scallnr = ureg->r0;
 	up->scallnr = scallnr;
-	if(scallnr == RFORK)
-		fpusysrfork(ureg);
 	spllo();
 	sp = ureg->sp;
 
@@ -361,6 +359,4 @@ forkchild(Proc *p, Ureg *ureg)
 	/* Things from bottom of syscall which were never executed */
 	p->psstate = 0;
 	p->insyscall = 0;
-
-	fpusysrforkchild(p, cureg, up);
 }

sys/src/9/teg2/vfp3.c

@@ -239,33 +239,6 @@ fpunoted(void)
 	up->fpstate &= ~FPillegal;
 }
 
-/*
- * Called early in the non-interruptible path of
- * sysrfork() via the machine-dependent syscall() routine.
- * Save the state so that it can be easily copied
- * to the child process later.
- */
-void
-fpusysrfork(Ureg*)
-{
-	if(up->fpstate == FPactive){
-		fpsave(&up->fpsave);
-		up->fpstate = FPinactive;
-	}
-}
-
-/*
- * Called later in sysrfork() via the machine-dependent
- * sysrforkchild() routine.
- * Copy the parent FPU state to the child.
- */
-void
-fpusysrforkchild(Proc *p, Ureg *, Proc *up)
-{
-	/* don't penalize the child, it hasn't done FP in a note handler. */
-	p->fpstate = up->fpstate & ~FPillegal;
-}
-
 /* should only be called if p->fpstate == FPactive */
 void
 fpsave(FPsave *fps)