Commit 0f2793e3 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/32: Perform normal function call in exception entry 



Now that the MMU is re-enabled before calling the transfer function,
we don't need anymore that hack with the address of the handler and
the return function sitting just after the 'bl' to the transfer
fonction, that function is retrieving via a read relative to 'lr'.

Do a regular call to the transfer function, then to the handler,
then branch to the return function.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/73c00f3361ca280ef8fd7814c291bd1f5b6e2081.1615552867.git.christophe.leroy@csgroup.eu
parent 32d2ca0e

arch/powerpc/kernel/entry_32.S

+4 −10
Original line number Diff line number Diff line
@@ -104,7 +104,7 @@ transfer_to_handler: 
#ifdef CONFIG_PPC_BOOK3S_32

	kuep_lock r11, r12

#endif

	b	3f

	blr



	/* if from kernel, check interrupted DOZE/NAP mode */

2:
@@ -118,13 +118,7 @@ transfer_to_handler: 
#endif /* CONFIG_PPC_BOOK3S_32 || CONFIG_E500 */

	.globl transfer_to_handler_cont

transfer_to_handler_cont:

3:

	mflr	r9

	lwz	r11,0(r9)		/* virtual address of handler */

	lwz	r9,4(r9)		/* where to go when done */

	mtctr	r11

	mtlr	r9

	bctr				/* jump to handler */

	blr



#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)

4:	rlwinm	r12,r12,0,~_TLF_NAPPING
@@ -404,8 +398,8 @@ fee_restarts: 
	stw	r10,_TRAP(r11)

	addi	r3,r1,STACK_FRAME_OVERHEAD

	bl	transfer_to_handler_full

	.long	unrecoverable_exception

	.long	ret_from_except

	bl	unrecoverable_exception

	b	ret_from_except

#endif



	.globl	ret_from_except_full

arch/powerpc/kernel/head_32.h

+2 −2
Original line number Diff line number Diff line
@@ -190,8 +190,8 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt) 
	li	r10,trap;					\

	stw	r10,_TRAP(r11);					\

	bl	tfer;						\

	.long	hdlr;						\

	.long	ret

	bl	hdlr;						\

	b	ret



#define EXC_XFER_STD(n, hdlr)		\

	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler_full,	\

arch/powerpc/kernel/head_booke.h

+3 −3
Original line number Diff line number Diff line
@@ -323,8 +323,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) 
	li	r10,trap;					\

	stw	r10,_TRAP(r11);					\

	bl	tfer;						\

	.long	hdlr;						\

	.long	ret

	bl	hdlr;						\

	b	ret;						\



#define EXC_XFER_STD(n, hdlr)		\

	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler_full, \