[RFC PATCH v1 21/41] powerpc/32: Refactor booke critical registers saving

From: Christophe Leroy
Date: Tue Feb 09 2021 - 05:13:11 EST


Refactor booke critical registers saving into a few macros
and move it into the exception prolog directly.

Keep the dedicated transfert_to_handler entry point for the
moment allthough they are empty. They will be removed in a
later patch to reduce churn.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/entry_32.S | 33 -------------------------
arch/powerpc/kernel/head_booke.h | 41 ++++++++++++++++++++++++++++++++
2 files changed, 41 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index f244e7846031..dce0f03a0e88 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -51,49 +51,16 @@
#ifdef CONFIG_BOOKE
.globl mcheck_transfer_to_handler
mcheck_transfer_to_handler:
- mfspr r0,SPRN_DSRR0
- stw r0,_DSRR0(r11)
- mfspr r0,SPRN_DSRR1
- stw r0,_DSRR1(r11)
/* fall through */
_ASM_NOKPROBE_SYMBOL(mcheck_transfer_to_handler)

.globl debug_transfer_to_handler
debug_transfer_to_handler:
- mfspr r0,SPRN_CSRR0
- stw r0,_CSRR0(r11)
- mfspr r0,SPRN_CSRR1
- stw r0,_CSRR1(r11)
/* fall through */
_ASM_NOKPROBE_SYMBOL(debug_transfer_to_handler)

.globl crit_transfer_to_handler
crit_transfer_to_handler:
-#ifdef CONFIG_PPC_BOOK3E_MMU
- mfspr r0,SPRN_MAS0
- stw r0,MAS0(r11)
- mfspr r0,SPRN_MAS1
- stw r0,MAS1(r11)
- mfspr r0,SPRN_MAS2
- stw r0,MAS2(r11)
- mfspr r0,SPRN_MAS3
- stw r0,MAS3(r11)
- mfspr r0,SPRN_MAS6
- stw r0,MAS6(r11)
-#ifdef CONFIG_PHYS_64BIT
- mfspr r0,SPRN_MAS7
- stw r0,MAS7(r11)
-#endif /* CONFIG_PHYS_64BIT */
-#endif /* CONFIG_PPC_BOOK3E_MMU */
-#ifdef CONFIG_44x
- mfspr r0,SPRN_MMUCR
- stw r0,MMUCR(r11)
-#endif
- mfspr r0,SPRN_SRR0
- stw r0,_SRR0(r11)
- mfspr r0,SPRN_SRR1
- stw r0,_SRR1(r11)
-
/* fall through */
_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#endif
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index ff93ed519b3b..a57a312c7f86 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -229,6 +229,36 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
SAVE_4GPRS(3, r11); \
SAVE_2GPRS(7, r11)

+.macro SAVE_xSRR xSRR
+ mfspr r0,SPRN_\xSRR\()0
+ stw r0,_\xSRR\()0(r1)
+ mfspr r0,SPRN_\xSRR\()1
+ stw r0,_\xSRR\()1(r1)
+.endm
+
+.macro SAVE_MMU_REGS
+#ifdef CONFIG_PPC_BOOK3E_MMU
+ mfspr r0,SPRN_MAS0
+ stw r0,MAS0(r1)
+ mfspr r0,SPRN_MAS1
+ stw r0,MAS1(r1)
+ mfspr r0,SPRN_MAS2
+ stw r0,MAS2(r1)
+ mfspr r0,SPRN_MAS3
+ stw r0,MAS3(r1)
+ mfspr r0,SPRN_MAS6
+ stw r0,MAS6(r1)
+#ifdef CONFIG_PHYS_64BIT
+ mfspr r0,SPRN_MAS7
+ stw r0,MAS7(r1)
+#endif /* CONFIG_PHYS_64BIT */
+#endif /* CONFIG_PPC_BOOK3E_MMU */
+#ifdef CONFIG_44x
+ mfspr r0,SPRN_MMUCR
+ stw r0,MMUCR(r1)
+#endif
+.endm
+
#define CRITICAL_EXCEPTION_PROLOG(intno) \
EXC_LEVEL_EXCEPTION_PROLOG(CRIT, intno, SPRN_CSRR0, SPRN_CSRR1)
#define DEBUG_EXCEPTION_PROLOG \
@@ -271,6 +301,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
START_EXCEPTION(label); \
CRITICAL_EXCEPTION_PROLOG(intno); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
+ SAVE_MMU_REGS; \
+ SAVE_xSRR SRR; \
EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
crit_transfer_to_handler, ret_from_crit_exc)

@@ -280,6 +312,10 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
mfspr r5,SPRN_ESR; \
stw r5,_ESR(r11); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
+ SAVE_xSRR DSRR; \
+ SAVE_xSRR CSRR; \
+ SAVE_MMU_REGS; \
+ SAVE_xSRR SRR; \
EXC_XFER_TEMPLATE(hdlr, n+4, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
mcheck_transfer_to_handler, ret_from_mcheck_exc)

@@ -363,6 +399,9 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
2: mfspr r4,SPRN_DBSR; \
stw r4,_ESR(r11); /* DebugException takes DBSR in _ESR */\
addi r3,r1,STACK_FRAME_OVERHEAD; \
+ SAVE_xSRR CSRR; \
+ SAVE_MMU_REGS; \
+ SAVE_xSRR SRR; \
EXC_XFER_TEMPLATE(DebugException, 0x2008, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), debug_transfer_to_handler, ret_from_debug_exc)

#define DEBUG_CRIT_EXCEPTION \
@@ -417,6 +456,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
2: mfspr r4,SPRN_DBSR; \
stw r4,_ESR(r11); /* DebugException takes DBSR in _ESR */\
addi r3,r1,STACK_FRAME_OVERHEAD; \
+ SAVE_MMU_REGS; \
+ SAVE_xSRR SRR; \
EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), crit_transfer_to_handler, ret_from_crit_exc)

#define DATA_STORAGE_EXCEPTION \
--
2.25.0