[PATCH] ppc32: refactor FPU exception handling

Moved common FPU exception handling code out of head.S so it can be used by
several of the sub-architectures that might of a full PowerPC FPU.

Also, uses new CONFIG_PPC_FPU define to fix alignment exception handling
for floating point load/store instructions to only occur if we have a
hardware FPU.

Signed-off-by: Jason McMullan <jason.mcmullan@timesys.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 163 deletions

diff --git a/arch/ppc/kernel/head.S b/arch/ppc/kernel/head.S
index 1a89a71..a931d77 100644
--- a/arch/ppc/kernel/head.S
+++ b/arch/ppc/kernel/head.S
@@ -775,133 +775,6 @@ InstructionSegment:
 	EXC_XFER_STD(0x480, UnknownException)
 #endif /* CONFIG_PPC64BRIDGE */
 
-/*
- * This task wants to use the FPU now.
- * On UP, disable FP for the task which had the FPU previously,
- * and save its floating-point registers in its thread_struct.
- * Load up this task's FP registers from its thread_struct,
- * enable the FPU for the current task and return to the task.
- */
-load_up_fpu:
-	mfmsr	r5
-	ori	r5,r5,MSR_FP
-#ifdef CONFIG_PPC64BRIDGE
-	clrldi	r5,r5,1			/* turn off 64-bit mode */
-#endif /* CONFIG_PPC64BRIDGE */
-	SYNC
-	MTMSRD(r5)			/* enable use of fpu now */
-	isync
-/*
- * For SMP, we don't do lazy FPU switching because it just gets too
- * horrendously complex, especially when a task switches from one CPU
- * to another.  Instead we call giveup_fpu in switch_to.
- */
-#ifndef CONFIG_SMP
-	tophys(r6,0)			/* get __pa constant */
-	addis	r3,r6,last_task_used_math@ha
-	lwz	r4,last_task_used_math@l(r3)
-	cmpwi	0,r4,0
-	beq	1f
-	add	r4,r4,r6
-	addi	r4,r4,THREAD		/* want last_task_used_math->thread */
-	SAVE_32FPRS(0, r4)
-	mffs	fr0
-	stfd	fr0,THREAD_FPSCR-4(r4)
-	lwz	r5,PT_REGS(r4)
-	add	r5,r5,r6
-	lwz	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-	li	r10,MSR_FP|MSR_FE0|MSR_FE1
-	andc	r4,r4,r10		/* disable FP for previous task */
-	stw	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-1:
-#endif /* CONFIG_SMP */
-	/* enable use of FP after return */
-	mfspr	r5,SPRN_SPRG3		/* current task's THREAD (phys) */
-	lwz	r4,THREAD_FPEXC_MODE(r5)
-	ori	r9,r9,MSR_FP		/* enable FP for current */
-	or	r9,r9,r4
-	lfd	fr0,THREAD_FPSCR-4(r5)
-	mtfsf	0xff,fr0
-	REST_32FPRS(0, r5)
-#ifndef CONFIG_SMP
-	subi	r4,r5,THREAD
-	sub	r4,r4,r6
-	stw	r4,last_task_used_math@l(r3)
-#endif /* CONFIG_SMP */
-	/* restore registers and return */
-	/* we haven't used ctr or xer or lr */
-	/* fall through to fast_exception_return */
-
-	.globl	fast_exception_return
-fast_exception_return:
-	andi.	r10,r9,MSR_RI		/* check for recoverable interrupt */
-	beq	1f			/* if not, we've got problems */
-2:	REST_4GPRS(3, r11)
-	lwz	r10,_CCR(r11)
-	REST_GPR(1, r11)
-	mtcr	r10
-	lwz	r10,_LINK(r11)
-	mtlr	r10
-	REST_GPR(10, r11)
-	mtspr	SPRN_SRR1,r9
-	mtspr	SPRN_SRR0,r12
-	REST_GPR(9, r11)
-	REST_GPR(12, r11)
-	lwz	r11,GPR11(r11)
-	SYNC
-	RFI
-
-/* check if the exception happened in a restartable section */
-1:	lis	r3,exc_exit_restart_end@ha
-	addi	r3,r3,exc_exit_restart_end@l
-	cmplw	r12,r3
-	bge	3f
-	lis	r4,exc_exit_restart@ha
-	addi	r4,r4,exc_exit_restart@l
-	cmplw	r12,r4
-	blt	3f
-	lis	r3,fee_restarts@ha
-	tophys(r3,r3)
-	lwz	r5,fee_restarts@l(r3)
-	addi	r5,r5,1
-	stw	r5,fee_restarts@l(r3)
-	mr	r12,r4		/* restart at exc_exit_restart */
-	b	2b
-
-	.comm	fee_restarts,4
-
-/* aargh, a nonrecoverable interrupt, panic */
-/* aargh, we don't know which trap this is */
-/* but the 601 doesn't implement the RI bit, so assume it's OK */
-3:
-BEGIN_FTR_SECTION
-	b	2b
-END_FTR_SECTION_IFSET(CPU_FTR_601)
-	li	r10,-1
-	stw	r10,TRAP(r11)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	li	r10,MSR_KERNEL
-	bl	transfer_to_handler_full
-	.long	nonrecoverable_exception
-	.long	ret_from_except
-
-/*
- * FP unavailable trap from kernel - print a message, but let
- * the task use FP in the kernel until it returns to user mode.
- */
-KernelFP:
-	lwz	r3,_MSR(r1)
-	ori	r3,r3,MSR_FP
-	stw	r3,_MSR(r1)		/* enable use of FP after return */
-	lis	r3,86f@h
-	ori	r3,r3,86f@l
-	mr	r4,r2			/* current */
-	lwz	r5,_NIP(r1)
-	bl	printk
-	b	ret_from_except
-86:	.string	"floating point used in kernel (task=%p, pc=%x)\n"
-	.align	4,0
-
 #ifdef CONFIG_ALTIVEC
 /* Note that the AltiVec support is closely modeled after the FP
  * support.  Changes to one are likely to be applicable to the
@@ -1016,42 +889,6 @@ giveup_altivec:
 #endif /* CONFIG_ALTIVEC */
 
 /*
- * giveup_fpu(tsk)
- * Disable FP for the task given as the argument,
- * and save the floating-point registers in its thread_struct.
- * Enables the FPU for use in the kernel on return.
- */
-	.globl	giveup_fpu
-giveup_fpu:
-	mfmsr	r5
-	ori	r5,r5,MSR_FP
-	SYNC_601
-	ISYNC_601
-	MTMSRD(r5)			/* enable use of fpu now */
-	SYNC_601
-	isync
-	cmpwi	0,r3,0
-	beqlr-				/* if no previous owner, done */
-	addi	r3,r3,THREAD	        /* want THREAD of task */
-	lwz	r5,PT_REGS(r3)
-	cmpwi	0,r5,0
-	SAVE_32FPRS(0, r3)
-	mffs	fr0
-	stfd	fr0,THREAD_FPSCR-4(r3)
-	beq	1f
-	lwz	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-	li	r3,MSR_FP|MSR_FE0|MSR_FE1
-	andc	r4,r4,r3		/* disable FP for previous task */
-	stw	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-1:
-#ifndef CONFIG_SMP
-	li	r5,0
-	lis	r4,last_task_used_math@ha
-	stw	r5,last_task_used_math@l(r4)
-#endif /* CONFIG_SMP */
-	blr
-
-/*
  * This code is jumped to from the startup code to copy
  * the kernel image to physical address 0.
  */