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Subject[RFC PATCH v1 22/41] powerpc/32: Perform normal function call in exception entry
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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 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: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 14 ++++----------
arch/powerpc/kernel/head_32.h | 4 ++--
arch/powerpc/kernel/head_booke.h | 6 +++---
3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index dce0f03a0e88..e448ee3f5f15 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -104,7 +104,7 @@ transfer_to_handler:
#ifdef CONFIG_PPC_BOOK3S_32
kuep_lock r11, r12
#endif
- b 3f
+ blr

2: /* if from kernel, check interrupted DOZE/NAP mode and
* check for stack overflow
@@ -119,13 +119,7 @@ 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
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 160ebd573c37..e09585b88ba7 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -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, \
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index a57a312c7f86..4286f04648f8 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -322,9 +322,9 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
#define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret) \
li r10,trap; \
stw r10,_TRAP(r11); \
- bl tfer; \
- .long hdlr; \
- .long ret
+ bl tfer; \
+ bl hdlr; \
+ b ret; \

#define EXC_XFER_STD(n, hdlr) \
EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler_full, \
--
2.25.0
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