Make fork work, at least for kthreads. Switching still has some issues.

11 files changed, 77 insertions, 110 deletions

diff --git a/sys/powerpc/aim/locore.S b/sys/powerpc/aim/locore.S
index 76fc3aa..79c575d 100644
--- a/sys/powerpc/aim/locore.S
+++ b/sys/powerpc/aim/locore.S
@@ -940,24 +940,6 @@ s_trap:
 	rfi
 
 /*
- * Child comes here at the end of a fork.
- * Mostly similar to the above.
- */
-	.globl	fork_trampoline
-fork_trampoline:
-	xor	3,3,3
-#if 0 /* XXX */
-	bl	lcsplx
-#endif
-	mtlr	31
-	mr	3,30
-	blrl				/* jump indirect to r31 */
-	mr	3,30
-	bl	ast
-	FRAME_LEAVE(tempsave)
-	rfi
-
-/*
  * DSI second stage fault handler
  */
 s_dsitrap:
diff --git a/sys/powerpc/aim/swtch.S b/sys/powerpc/aim/swtch.S
index 00bdbb3..828c6cd 100644
--- a/sys/powerpc/aim/swtch.S
+++ b/sys/powerpc/aim/swtch.S
@@ -121,3 +121,14 @@ ENTRY(savectx)
 	mfcr	%r4			/* Save the condition register */
 	stw	%r4,PCB_CONTEXT(%r3)
 	blr
+
+/*
+ * fork_trampoline()
+ * Set up the return from cpu_fork()
+ */
+ENTRY(fork_trampoline)
+	lwz	%r3,CF_FUNC(1)
+	lwz	%r4,CF_ARG0(1)
+	lwz	%r5,CF_ARG1(1)
+	bl	fork_exit
+	rfi
diff --git a/sys/powerpc/aim/vm_machdep.c b/sys/powerpc/aim/vm_machdep.c
index 6958373..36345ec 100644
--- a/sys/powerpc/aim/vm_machdep.c
+++ b/sys/powerpc/aim/vm_machdep.c
@@ -128,7 +128,7 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 	struct	switchframe *sf;
 	struct	pcb *pcb;
 
-	KASSERT(td1 == curthread || td1 == thread0,
+	KASSERT(td1 == curthread || td1 == &thread0,
 	    ("cpu_fork: p1 not curproc and not proc0"));
 	CTR3(KTR_PROC, "cpu_fork: called td1=%08x p2=%08x flags=%x", (u_int)td1, (u_int)p2, flags);
 
@@ -137,8 +137,8 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 
 	p1 = td1->td_proc;
 
-	pcb = (struct pcb *)(td2->td_kstack + KSTACK_PAGES * PAGE_SIZE -
-	    sizeof(struct pcb));
+	pcb = (struct pcb *)((td2->td_kstack + KSTACK_PAGES * PAGE_SIZE -
+	    sizeof(struct pcb)) & ~0x2fU);
 	td2->td_pcb = pcb;
 
 	/* Copy the pcb */
@@ -149,7 +149,6 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 	 * Copy the trap frame for the return to user mode as if from a
 	 * syscall.  This copies most of the user mode register values.
 	 */
-
 	tf = (struct trapframe *)pcb - 1;
 	bcopy(td1->td_frame, tf, sizeof(*tf));
 
@@ -157,18 +156,13 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 
 	td2->td_frame = tf;
 
-	/*
-	 * There happens to be a callframe, too.
-	 */
 	cf = (struct callframe *)tf - 1;
-	cf->lr = (int)fork_trampoline;
+	cf->cf_func = (register_t)fork_return;
+	cf->cf_arg0 = (register_t)td2;
+	cf->cf_arg1 = (register_t)tf;
 
-	/*
-	 * Below that, we allocate the switch frame.
-	 */
-	sf = (struct switchframe *)cf - 1;
-	sf->sp = (int)cf;
-	pcb->pcb_sp = (int)sf;
+	pcb->pcb_sp = (register_t)cf;
+	pcb->pcb_lr = (register_t)fork_trampoline;
 
 	/*
  	 * Now cpu_switch() can schedule the new process.
@@ -187,17 +181,15 @@ cpu_set_fork_handler(td, func, arg)
 	void (*func) __P((void *));
 	void *arg;
 {
-	struct	switchframe *sf;
 	struct	callframe *cf;
 
 	CTR3(KTR_PROC, "cpu_set_fork_handler: called with td=%08x func=%08x arg=%08x",
 	    (u_int)td, (u_int)func, (u_int)arg);
 
-	sf = (struct switchframe *)td->td_pcb->pcb_sp;
-	cf = (struct callframe *)sf->sp;
+	cf = (struct callframe *)td->td_pcb->pcb_sp;
 
-	cf->r31 = (register_t)func;
-	cf->r30 = (register_t)arg;
+	cf->cf_func = (register_t)func;
+	cf->cf_arg0 = (register_t)arg;
 }
 
 /*
diff --git a/sys/powerpc/include/frame.h b/sys/powerpc/include/frame.h
index 3865de4..72dbd9f 100644
--- a/sys/powerpc/include/frame.h
+++ b/sys/powerpc/include/frame.h
@@ -67,9 +67,9 @@ struct trapframe {
 
 struct switchframe {
 	register_t sp;
-	int fill;
-	int user_sr;
-	int cr;
+	register_t fill;
+	register_t user_sr;
+	register_t cr;
 	register_t fixreg2;
 	register_t fixreg[19];		/* R13-R31 */
 };
@@ -85,10 +85,9 @@ struct clockframe {
  * Call frame for PowerPC used during fork.
  */
 struct callframe {
-	register_t sp;
-	register_t lr;
-	register_t r30;
-	register_t r31;
+	register_t	cf_func;
+	register_t	cf_arg0;
+	register_t	cf_arg1;
 };
 
 #endif	/* _MACHINE_FRAME_H_ */
diff --git a/sys/powerpc/include/pcb.h b/sys/powerpc/include/pcb.h
index 98b6fa9..fbd7cbf 100644
--- a/sys/powerpc/include/pcb.h
+++ b/sys/powerpc/include/pcb.h
@@ -38,18 +38,19 @@
 typedef int faultbuf[23];
 
 struct pcb {
-	u_int32_t pcb_context[18];	/* non-volatile r14-r31 */
-	u_int32_t pcb_cr;		/* Condition register */
-	struct pmap *pcb_pm;	/* pmap of our vmspace */
-	struct pmap *pcb_pmreal; /* real address of above */
-	register_t pcb_sp;	/* saved SP */
-	int pcb_spl;		/* saved SPL */
-	faultbuf *pcb_onfault;	/* For use during copyin/copyout */
-	int pcb_flags;
+	register_t	pcb_context[18];	/* non-volatile r14-r31 */
+	register_t	pcb_cr;			/* Condition register */
+	register_t	pcb_sp;			/* stack pointer */
+	register_t	pcb_lr;			/* link register */
+	struct		pmap *pcb_pm;		/* pmap of our vmspace */
+	struct		pmap *pcb_pmreal;	 /* real address of above */
+	faultbuf	*pcb_onfault;		/* For use during
+						    copyin/copyout */
+	int		pcb_flags;
 #define	PCB_FPU		1	/* Process had FPU initialized */
 	struct fpu {
-		double fpr[32];
-		double fpscr;	/* FPSCR stored as double for easier access */
+		double	fpr[32];
+		double	fpscr;	/* FPSCR stored as double for easier access */
 	} pcb_fpu;		/* Floating point processor */
 };
 
diff --git a/sys/powerpc/powerpc/genassym.c b/sys/powerpc/powerpc/genassym.c
index f0b28d4..c8a484b 100644
--- a/sys/powerpc/powerpc/genassym.c
+++ b/sys/powerpc/powerpc/genassym.c
@@ -86,11 +86,15 @@ ASSYM(FRAME_EXC, offsetof(struct trapframe, exc));
 
 ASSYM(SFRAMELEN, roundup(sizeof(struct switchframe), 16));
 
+ASSYM(CF_FUNC, offsetof(struct callframe, cf_func));
+ASSYM(CF_ARG0, offsetof(struct callframe, cf_arg0));
+ASSYM(CF_ARG1, offsetof(struct callframe, cf_arg1));
+
 ASSYM(PCB_CONTEXT, offsetof(struct pcb, pcb_context));
 ASSYM(PCB_CR, offsetof(struct pcb, pcb_cr));
 ASSYM(PCB_PMR, offsetof(struct pcb, pcb_pmreal));
 ASSYM(PCB_SP, offsetof(struct pcb, pcb_sp));
-ASSYM(PCB_SPL, offsetof(struct pcb, pcb_spl));
+ASSYM(PCB_LR, offsetof(struct pcb, pcb_lr));
 ASSYM(PCB_ONFAULT, offsetof(struct pcb, pcb_onfault));
 ASSYM(PCB_FLAGS, offsetof(struct pcb, pcb_flags));
 
diff --git a/sys/powerpc/powerpc/locore.S b/sys/powerpc/powerpc/locore.S
index 76fc3aa..79c575d 100644
--- a/sys/powerpc/powerpc/locore.S
+++ b/sys/powerpc/powerpc/locore.S
@@ -940,24 +940,6 @@ s_trap:
 	rfi
 
 /*
- * Child comes here at the end of a fork.
- * Mostly similar to the above.
- */
-	.globl	fork_trampoline
-fork_trampoline:
-	xor	3,3,3
-#if 0 /* XXX */
-	bl	lcsplx
-#endif
-	mtlr	31
-	mr	3,30
-	blrl				/* jump indirect to r31 */
-	mr	3,30
-	bl	ast
-	FRAME_LEAVE(tempsave)
-	rfi
-
-/*
  * DSI second stage fault handler
  */
 s_dsitrap:
diff --git a/sys/powerpc/powerpc/locore.s b/sys/powerpc/powerpc/locore.s
index 76fc3aa..79c575d 100644
--- a/sys/powerpc/powerpc/locore.s
+++ b/sys/powerpc/powerpc/locore.s
@@ -940,24 +940,6 @@ s_trap:
 	rfi
 
 /*
- * Child comes here at the end of a fork.
- * Mostly similar to the above.
- */
-	.globl	fork_trampoline
-fork_trampoline:
-	xor	3,3,3
-#if 0 /* XXX */
-	bl	lcsplx
-#endif
-	mtlr	31
-	mr	3,30
-	blrl				/* jump indirect to r31 */
-	mr	3,30
-	bl	ast
-	FRAME_LEAVE(tempsave)
-	rfi
-
-/*
  * DSI second stage fault handler
  */
 s_dsitrap:
diff --git a/sys/powerpc/powerpc/swtch.S b/sys/powerpc/powerpc/swtch.S
index 00bdbb3..828c6cd 100644
--- a/sys/powerpc/powerpc/swtch.S
+++ b/sys/powerpc/powerpc/swtch.S
@@ -121,3 +121,14 @@ ENTRY(savectx)
 	mfcr	%r4			/* Save the condition register */
 	stw	%r4,PCB_CONTEXT(%r3)
 	blr
+
+/*
+ * fork_trampoline()
+ * Set up the return from cpu_fork()
+ */
+ENTRY(fork_trampoline)
+	lwz	%r3,CF_FUNC(1)
+	lwz	%r4,CF_ARG0(1)
+	lwz	%r5,CF_ARG1(1)
+	bl	fork_exit
+	rfi
diff --git a/sys/powerpc/powerpc/swtch.s b/sys/powerpc/powerpc/swtch.s
index 00bdbb3..828c6cd 100644
--- a/sys/powerpc/powerpc/swtch.s
+++ b/sys/powerpc/powerpc/swtch.s
@@ -121,3 +121,14 @@ ENTRY(savectx)
 	mfcr	%r4			/* Save the condition register */
 	stw	%r4,PCB_CONTEXT(%r3)
 	blr
+
+/*
+ * fork_trampoline()
+ * Set up the return from cpu_fork()
+ */
+ENTRY(fork_trampoline)
+	lwz	%r3,CF_FUNC(1)
+	lwz	%r4,CF_ARG0(1)
+	lwz	%r5,CF_ARG1(1)
+	bl	fork_exit
+	rfi
diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c
index 6958373..36345ec 100644
--- a/sys/powerpc/powerpc/vm_machdep.c
+++ b/sys/powerpc/powerpc/vm_machdep.c
@@ -128,7 +128,7 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 	struct	switchframe *sf;
 	struct	pcb *pcb;
 
-	KASSERT(td1 == curthread || td1 == thread0,
+	KASSERT(td1 == curthread || td1 == &thread0,
 	    ("cpu_fork: p1 not curproc and not proc0"));
 	CTR3(KTR_PROC, "cpu_fork: called td1=%08x p2=%08x flags=%x", (u_int)td1, (u_int)p2, flags);
 
@@ -137,8 +137,8 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 
 	p1 = td1->td_proc;
 
-	pcb = (struct pcb *)(td2->td_kstack + KSTACK_PAGES * PAGE_SIZE -
-	    sizeof(struct pcb));
+	pcb = (struct pcb *)((td2->td_kstack + KSTACK_PAGES * PAGE_SIZE -
+	    sizeof(struct pcb)) & ~0x2fU);
 	td2->td_pcb = pcb;
 
 	/* Copy the pcb */
@@ -149,7 +149,6 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 	 * Copy the trap frame for the return to user mode as if from a
 	 * syscall.  This copies most of the user mode register values.
 	 */
-
 	tf = (struct trapframe *)pcb - 1;
 	bcopy(td1->td_frame, tf, sizeof(*tf));
 
@@ -157,18 +156,13 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 
 	td2->td_frame = tf;
 
-	/*
-	 * There happens to be a callframe, too.
-	 */
 	cf = (struct callframe *)tf - 1;
-	cf->lr = (int)fork_trampoline;
+	cf->cf_func = (register_t)fork_return;
+	cf->cf_arg0 = (register_t)td2;
+	cf->cf_arg1 = (register_t)tf;
 
-	/*
-	 * Below that, we allocate the switch frame.
-	 */
-	sf = (struct switchframe *)cf - 1;
-	sf->sp = (int)cf;
-	pcb->pcb_sp = (int)sf;
+	pcb->pcb_sp = (register_t)cf;
+	pcb->pcb_lr = (register_t)fork_trampoline;
 
 	/*
  	 * Now cpu_switch() can schedule the new process.
@@ -187,17 +181,15 @@ cpu_set_fork_handler(td, func, arg)
 	void (*func) __P((void *));
 	void *arg;
 {
-	struct	switchframe *sf;
 	struct	callframe *cf;
 
 	CTR3(KTR_PROC, "cpu_set_fork_handler: called with td=%08x func=%08x arg=%08x",
 	    (u_int)td, (u_int)func, (u_int)arg);
 
-	sf = (struct switchframe *)td->td_pcb->pcb_sp;
-	cf = (struct callframe *)sf->sp;
+	cf = (struct callframe *)td->td_pcb->pcb_sp;
 
-	cf->r31 = (register_t)func;
-	cf->r30 = (register_t)arg;
+	cf->cf_func = (register_t)func;
+	cf->cf_arg0 = (register_t)arg;
 }
 
 /*