Add the USER_SR segment register to pcb state. Initialize correctly,

and save/restore during a context switch.

The USER_SR could be overwritten when the current thread was switched
out with a faulting copyin/copyout.

Approved by: Benno

7 files changed, 22 insertions, 0 deletions

diff --git a/sys/powerpc/aim/swtch.S b/sys/powerpc/aim/swtch.S
index e02367a..188d5cf 100644
--- a/sys/powerpc/aim/swtch.S
+++ b/sys/powerpc/aim/swtch.S
@@ -83,6 +83,9 @@ ENTRY(cpu_switch)
 	stw	%r16,PCB_CR(%r3)
 	mflr	%r16			/* Save the link register */
 	stw	%r16,PCB_LR(%r3)
+	mfsr	%r16,USER_SR		/* Save USER_SR for copyin/out */
+	isync
+	stw	%r16,PCB_USR(%r3)
 	stw	%r1,PCB_SP(%r3)		/* Save the stack pointer */
 
 #if 0
@@ -128,6 +131,9 @@ ENTRY(cpu_switch)
 	mtcr	%r5
 	lwz	%r5,PCB_LR(%r3)		/* Load the link register */
 	mtlr	%r5
+	lwz	%r5,PCB_USR(%r3)	/* Load the USER_SR segment reg */
+	mtsr	USER_SR,%r5
+	isync
 	lwz	%r1,PCB_SP(%r3)		/* Load the stack pointer */
 	blr
 
diff --git a/sys/powerpc/aim/vm_machdep.c b/sys/powerpc/aim/vm_machdep.c
index 5d4f6eb..284a031 100644
--- a/sys/powerpc/aim/vm_machdep.c
+++ b/sys/powerpc/aim/vm_machdep.c
@@ -166,6 +166,7 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 
 	pcb->pcb_sp = (register_t)cf;
 	pcb->pcb_lr = (register_t)fork_trampoline;
+	pcb->pcb_usr = kernel_pmap->pm_sr[USER_SR];
 
 	/*
  	 * Now cpu_switch() can schedule the new process.
diff --git a/sys/powerpc/include/pcb.h b/sys/powerpc/include/pcb.h
index c2042f2..a461b34 100644
--- a/sys/powerpc/include/pcb.h
+++ b/sys/powerpc/include/pcb.h
@@ -42,6 +42,7 @@ struct pcb {
 	register_t	pcb_cr;			/* Condition register */
 	register_t	pcb_sp;			/* stack pointer */
 	register_t	pcb_lr;			/* link register */
+	register_t	pcb_usr;		/* USER_SR segment register */
 	struct		pmap *pcb_pm;		/* pmap of our vmspace */
 	struct		pmap *pcb_pmreal;	 /* real address of above */
 	faultbuf	*pcb_onfault;		/* For use during
diff --git a/sys/powerpc/powerpc/genassym.c b/sys/powerpc/powerpc/genassym.c
index 0e1995d..02ca3d9 100644
--- a/sys/powerpc/powerpc/genassym.c
+++ b/sys/powerpc/powerpc/genassym.c
@@ -134,6 +134,7 @@ 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_LR, offsetof(struct pcb, pcb_lr));
+ASSYM(PCB_USR, offsetof(struct pcb, pcb_usr));
 ASSYM(PCB_ONFAULT, offsetof(struct pcb, pcb_onfault));
 ASSYM(PCB_FLAGS, offsetof(struct pcb, pcb_flags));
 
diff --git a/sys/powerpc/powerpc/swtch.S b/sys/powerpc/powerpc/swtch.S
index e02367a..188d5cf 100644
--- a/sys/powerpc/powerpc/swtch.S
+++ b/sys/powerpc/powerpc/swtch.S
@@ -83,6 +83,9 @@ ENTRY(cpu_switch)
 	stw	%r16,PCB_CR(%r3)
 	mflr	%r16			/* Save the link register */
 	stw	%r16,PCB_LR(%r3)
+	mfsr	%r16,USER_SR		/* Save USER_SR for copyin/out */
+	isync
+	stw	%r16,PCB_USR(%r3)
 	stw	%r1,PCB_SP(%r3)		/* Save the stack pointer */
 
 #if 0
@@ -128,6 +131,9 @@ ENTRY(cpu_switch)
 	mtcr	%r5
 	lwz	%r5,PCB_LR(%r3)		/* Load the link register */
 	mtlr	%r5
+	lwz	%r5,PCB_USR(%r3)	/* Load the USER_SR segment reg */
+	mtsr	USER_SR,%r5
+	isync
 	lwz	%r1,PCB_SP(%r3)		/* Load the stack pointer */
 	blr
 
diff --git a/sys/powerpc/powerpc/swtch.s b/sys/powerpc/powerpc/swtch.s
index e02367a..188d5cf 100644
--- a/sys/powerpc/powerpc/swtch.s
+++ b/sys/powerpc/powerpc/swtch.s
@@ -83,6 +83,9 @@ ENTRY(cpu_switch)
 	stw	%r16,PCB_CR(%r3)
 	mflr	%r16			/* Save the link register */
 	stw	%r16,PCB_LR(%r3)
+	mfsr	%r16,USER_SR		/* Save USER_SR for copyin/out */
+	isync
+	stw	%r16,PCB_USR(%r3)
 	stw	%r1,PCB_SP(%r3)		/* Save the stack pointer */
 
 #if 0
@@ -128,6 +131,9 @@ ENTRY(cpu_switch)
 	mtcr	%r5
 	lwz	%r5,PCB_LR(%r3)		/* Load the link register */
 	mtlr	%r5
+	lwz	%r5,PCB_USR(%r3)	/* Load the USER_SR segment reg */
+	mtsr	USER_SR,%r5
+	isync
 	lwz	%r1,PCB_SP(%r3)		/* Load the stack pointer */
 	blr
 
diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c
index 5d4f6eb..284a031 100644
--- a/sys/powerpc/powerpc/vm_machdep.c
+++ b/sys/powerpc/powerpc/vm_machdep.c
@@ -166,6 +166,7 @@ cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
 
 	pcb->pcb_sp = (register_t)cf;
 	pcb->pcb_lr = (register_t)fork_trampoline;
+	pcb->pcb_usr = kernel_pmap->pm_sr[USER_SR];
 
 	/*
  	 * Now cpu_switch() can schedule the new process.