Enable the FPU on first use per-thread and save state across context

switches. Not as lazy as it could be. Changing FPU state with sigcontext
still TODO.

fpu.c - convert some asm to inline C, and macroize fpu loads/stores
swtch.S - call out to save/restore fpu routines
trap.c - always call enable_fpu, since this shouldn't be called once
         the FPU has been enabled for a thread
genassym.c - define for pcb fpu flag

2 files changed, 11 insertions, 22 deletions

diff --git a/sys/powerpc/aim/swtch.S b/sys/powerpc/aim/swtch.S
index 188d5cf..49e23c8 100644
--- a/sys/powerpc/aim/swtch.S
+++ b/sys/powerpc/aim/swtch.S
@@ -88,12 +88,11 @@ ENTRY(cpu_switch)
 	stw	%r16,PCB_USR(%r3)
 	stw	%r1,PCB_SP(%r3)		/* Save the stack pointer */
 
-#if 0
-	lwz	%r29,PCB_FLAGS(%r3)
-	andi.	%r9, %r29, 1		/* XXX - don't hard code */
+	lwz	%r5,PCB_FLAGS(%r3)	/* Save FPU context if needed */
+	andi.	%r5, %r5, PCB_FPU
 	beq	.L1
+	mr	%r3,%r15
 	bl	save_fpu
-#endif
 
 .L1:
 	bl	choosethread		/* Find a new thread to run */
@@ -111,16 +110,14 @@ ENTRY(cpu_switch)
 	mfsprg	%r4,0			/* Get the pcpu pointer */
 	stw	%r16,PC_CURTHREAD(%r4)	/* Store new current thread */
 	mr	%r3,%r16		/*   and save in r3 */
-	lwz	%r16,TD_PCB(%r16)	/* Store new current PCB */
-	stw	%r16,PC_CURPCB(%r4)
+	lwz	%r17,TD_PCB(%r16)	/* Store new current PCB */
+	stw	%r17,PC_CURPCB(%r4)
 
-#if 0
-	lwz	%r29, PCB_FLAGS(%r4)	/* Restore FPU regs if needed */
-	andi.	%r9, %r29, 1
+	lwz	%r5, PCB_FLAGS(%r17)	/* Restore FPU context if needed */
+	andi.	%r5, %r5, PCB_FPU
 	beq	.L2
-	mr	%r3, %r4
 	bl	enable_fpu
-#endif
+	mr	%r3,%r16		/* Recover new curthread */
 
 	/* thread to restore is in r3 */
 .L2:
diff --git a/sys/powerpc/aim/trap.c b/sys/powerpc/aim/trap.c
index 83f0b86..cd4a50b 100644
--- a/sys/powerpc/aim/trap.c
+++ b/sys/powerpc/aim/trap.c
@@ -150,7 +150,7 @@ trapname(u_int vector)
 void
 trap(struct trapframe *frame)
 {
-	struct thread	*td, *fputhread;
+	struct thread	*td;
 	struct proc	*p;
 	int		sig, type, user;
 	u_int		sticks, ucode;
@@ -192,13 +192,9 @@ trap(struct trapframe *frame)
 			break;
 
 		case EXC_FPU:
-			if ((fputhread = PCPU_GET(fputhread)) != NULL) {
-				save_fpu(fputhread);
-			}
-			PCPU_SET(fputhread, td);
-			td->td_pcb->pcb_fpcpu = PCPU_GET(cpuid);
+			KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
+			    ("FPU already enabled for thread"));
 			enable_fpu(td);
-			frame->srr1 |= PSL_FP;
 			break;
 
 #ifdef	ALTIVEC
@@ -253,10 +249,6 @@ trap(struct trapframe *frame)
 		}
 	}
 
-	if (td != PCPU_GET(fputhread) ||
-	    td->td_pcb->pcb_fpcpu != PCPU_GET(cpuid))
-		frame->srr1 &= ~PSL_FP;
-
 #ifdef	ALTIVEC
 	if (td != PCPU_GET(vecthread) ||
 	    td->td_pcb->pcb_veccpu != PCPU_GET(cpuid))