[PATCH v1 08/15] powerpc/32: Split head_32.h into head_40x.h and head_6xx_8xx.h

From: Christophe Leroy
Date: Tue Dec 22 2020 - 08:30:19 EST


book3s/32 (aka 6xx) and 8xx head will be reworked to re-enable MMU
earlier.

Split 40x head.h out so that we can keep 40x as is until it
is phased out.

There is no plan to implement VMAP stack on 40x on the near future
so remove everything related.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/entry_32.S | 6 +-
arch/powerpc/kernel/head_40x.S | 2 +-
arch/powerpc/kernel/{head_32.h => head_40x.h} | 185 +-----------------
.../kernel/{head_32.h => head_6xx_8xx.h} | 39 +---
arch/powerpc/kernel/head_8xx.S | 2 +-
arch/powerpc/kernel/head_book3s_32.S | 4 +-
6 files changed, 18 insertions(+), 220 deletions(-)
copy arch/powerpc/kernel/{head_32.h => head_40x.h} (52%)
rename arch/powerpc/kernel/{head_32.h => head_6xx_8xx.h} (89%)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 05904334c0ff..c1687f3cd0ca 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -33,7 +33,11 @@
#include <asm/kup.h>
#include <asm/bug.h>

-#include "head_32.h"
+#ifdef CONFIG_40x
+#include "head_40x.h"
+#else
+#include "head_6xx_8xx.h"
+#endif

/*
* powerpc relies on return from interrupt/syscall being context synchronising
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 16dc0eecbdf9..050b5fdc0438 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -37,7 +37,7 @@
#include <asm/ptrace.h>
#include <asm/export.h>

-#include "head_32.h"
+#include "head_40x.h"

/* As with the other PowerPC ports, it is expected that when code
* execution begins here, the following registers contain valid, yet
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_40x.h
similarity index 52%
copy from arch/powerpc/kernel/head_32.h
copy to arch/powerpc/kernel/head_40x.h
index a2f72c966baf..9e27c07f5f2b 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_40x.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __HEAD_32_H__
-#define __HEAD_32_H__
+#ifndef __HEAD_40x_H__
+#define __HEAD_40x_H__

#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */

@@ -10,69 +10,21 @@
* We assume sprg3 has the physical address of the current
* task's thread_struct.
*/
-.macro EXCEPTION_PROLOG handle_dar_dsisr=0
- EXCEPTION_PROLOG_0 handle_dar_dsisr=\handle_dar_dsisr
- EXCEPTION_PROLOG_1
- EXCEPTION_PROLOG_2 handle_dar_dsisr=\handle_dar_dsisr
-.endm
-
-.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
+.macro EXCEPTION_PROLOG
mtspr SPRN_SPRG_SCRATCH0,r10
mtspr SPRN_SPRG_SCRATCH1,r11
-#ifdef CONFIG_VMAP_STACK
- mfspr r10, SPRN_SPRG_THREAD
- .if \handle_dar_dsisr
- mfspr r11, SPRN_DAR
- stw r11, DAR(r10)
- mfspr r11, SPRN_DSISR
- stw r11, DSISR(r10)
- .endif
- mfspr r11, SPRN_SRR0
- stw r11, SRR0(r10)
-#endif
mfspr r11, SPRN_SRR1 /* check whether user or kernel */
-#ifdef CONFIG_VMAP_STACK
- stw r11, SRR1(r10)
-#endif
mfcr r10
andi. r11, r11, MSR_PR
-.endm
-
-.macro EXCEPTION_PROLOG_1 for_rtas=0
-#ifdef CONFIG_VMAP_STACK
- mtspr SPRN_SPRG_SCRATCH2,r1
- subi r1, r1, INT_FRAME_SIZE /* use r1 if kernel */
- beq 1f
- mfspr r1,SPRN_SPRG_THREAD
- lwz r1,TASK_STACK-THREAD(r1)
- addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
-1:
- mtcrf 0x7f, r1
- bt 32 - THREAD_ALIGN_SHIFT, stack_overflow
-#else
subi r11, r1, INT_FRAME_SIZE /* use r1 if kernel */
beq 1f
mfspr r11,SPRN_SPRG_THREAD
lwz r11,TASK_STACK-THREAD(r11)
addi r11, r11, THREAD_SIZE - INT_FRAME_SIZE
1: tophys(r11, r11)
-#endif
-.endm
-
-.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
-#ifdef CONFIG_VMAP_STACK
- li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
- mtmsr r11
- isync
- mfspr r11, SPRN_SPRG_SCRATCH2
- stw r11,GPR1(r1)
- stw r11,0(r1)
- mr r11, r1
-#else
stw r1,GPR1(r11)
stw r1,0(r11)
tovirt(r1, r11) /* set new kernel sp */
-#endif
stw r10,_CCR(r11) /* save registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
@@ -82,31 +34,9 @@
stw r12,GPR11(r11)
mflr r10
stw r10,_LINK(r11)
-#ifdef CONFIG_VMAP_STACK
- mfspr r12, SPRN_SPRG_THREAD
- tovirt(r12, r12)
- .if \handle_dar_dsisr
- lwz r10, DAR(r12)
- stw r10, _DAR(r11)
- lwz r10, DSISR(r12)
- stw r10, _DSISR(r11)
- .endif
- lwz r9, SRR1(r12)
- lwz r12, SRR0(r12)
-#else
mfspr r12,SPRN_SRR0
mfspr r9,SPRN_SRR1
-#endif
-#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
-#else
-#ifdef CONFIG_VMAP_STACK
- li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
-#else
- li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */
-#endif
- mtmsr r10 /* (except for mach check in rtas) */
-#endif
stw r0,GPR0(r11)
lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
addi r10,r10,STACK_FRAME_REGS_MARKER@l
@@ -118,22 +48,6 @@
.macro SYSCALL_ENTRY trapno
mfspr r12,SPRN_SPRG_THREAD
mfspr r9, SPRN_SRR1
-#ifdef CONFIG_VMAP_STACK
- mfspr r11, SPRN_SRR0
- mtctr r11
- andi. r11, r9, MSR_PR
- mr r11, r1
- lwz r1,TASK_STACK-THREAD(r12)
- beq- 99f
- addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
- li r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
- mtmsr r10
- isync
- tovirt(r12, r12)
- stw r11,GPR1(r1)
- stw r11,0(r1)
- mr r11, r1
-#else
andi. r11, r9, MSR_PR
lwz r11,TASK_STACK-THREAD(r12)
beq- 99f
@@ -142,28 +56,14 @@
stw r1,GPR1(r11)
stw r1,0(r11)
tovirt(r1, r11) /* set new kernel sp */
-#endif
mflr r10
stw r10, _LINK(r11)
-#ifdef CONFIG_VMAP_STACK
- mfctr r10
-#else
mfspr r10,SPRN_SRR0
-#endif
stw r10,_NIP(r11)
mfcr r10
rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */
stw r10,_CCR(r11) /* save registers */
-#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
-#else
-#ifdef CONFIG_VMAP_STACK
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */
-#else
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR|MSR_DR)) /* can take exceptions */
-#endif
- mtmsr r10 /* (except for mach check in rtas) */
-#endif
lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
stw r2,GPR2(r11)
addi r10,r10,STACK_FRAME_REGS_MARKER@l
@@ -177,14 +77,11 @@
addi r11,r1,STACK_FRAME_OVERHEAD
addi r2,r12,-THREAD
stw r11,PT_REGS(r12)
-#if defined(CONFIG_40x)
/* Check to see if the dbcr0 register is set up to debug. Use the
internal debug mode bit to do this. */
lwz r12,THREAD_DBCR0(r12)
andis. r12,r12,DBCR0_IDM@h
-#endif
ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
-#if defined(CONFIG_40x)
beq+ 3f
/* From user and task is ptraced - load up global dbcr0 */
li r12,-1 /* clear all pending debug events */
@@ -197,10 +94,9 @@
lwz r12,4(r11)
addi r12,r12,-1
stw r12,4(r11)
-#endif

3:
- tovirt_novmstack r2, r2 /* set r2 to current */
+ tovirt(r2, r2) /* set r2 to current */
lis r11, transfer_to_syscall@h
ori r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
@@ -213,65 +109,26 @@
rlwimi r10, r9, 0, MSR_EE
#else
LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
-#endif
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
- mtspr SPRN_NRI, r0
#endif
mtspr SPRN_SRR1,r10
mtspr SPRN_SRR0,r11
rfi /* jump to handler, enable MMU */
-#ifdef CONFIG_40x
b . /* Prevent prefetch past rfi */
-#endif
99: b ret_from_kernel_syscall
.endm

-.macro save_dar_dsisr_on_stack reg1, reg2, sp
-#ifndef CONFIG_VMAP_STACK
- mfspr \reg1, SPRN_DAR
- mfspr \reg2, SPRN_DSISR
- stw \reg1, _DAR(\sp)
- stw \reg2, _DSISR(\sp)
-#endif
-.endm
-
-.macro get_and_save_dar_dsisr_on_stack reg1, reg2, sp
-#ifdef CONFIG_VMAP_STACK
- lwz \reg1, _DAR(\sp)
- lwz \reg2, _DSISR(\sp)
-#else
- save_dar_dsisr_on_stack \reg1, \reg2, \sp
-#endif
-.endm
-
.macro tovirt_vmstack dst, src
-#ifdef CONFIG_VMAP_STACK
- tovirt(\dst, \src)
-#else
.ifnc \dst, \src
mr \dst, \src
.endif
-#endif
.endm

.macro tovirt_novmstack dst, src
-#ifndef CONFIG_VMAP_STACK
tovirt(\dst, \src)
-#else
- .ifnc \dst, \src
- mr \dst, \src
- .endif
-#endif
.endm

.macro tophys_novmstack dst, src
-#ifndef CONFIG_VMAP_STACK
tophys(\dst, \src)
-#else
- .ifnc \dst, \src
- mr \dst, \src
- .endif
-#endif
.endm

/*
@@ -285,18 +142,10 @@
/*
* Exception vectors.
*/
-#ifdef CONFIG_PPC_BOOK3S
-#define START_EXCEPTION(n, label) \
- . = n; \
- DO_KVM n; \
-label:
-
-#else
#define START_EXCEPTION(n, label) \
. = n; \
label:

-#endif

#define EXCEPTION(n, label, hdlr, xfer) \
START_EXCEPTION(n, label) \
@@ -319,28 +168,4 @@
#define EXC_XFER_LITE(n, hdlr) \
EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, transfer_to_handler, \
ret_from_except)
-
-.macro vmap_stack_overflow_exception
-#ifdef CONFIG_VMAP_STACK
-#ifdef CONFIG_SMP
- mfspr r1, SPRN_SPRG_THREAD
- lwz r1, TASK_CPU - THREAD(r1)
- slwi r1, r1, 3
- addis r1, r1, emergency_ctx@ha
-#else
- lis r1, emergency_ctx@ha
-#endif
- lwz r1, emergency_ctx@l(r1)
- cmpwi cr1, r1, 0
- bne cr1, 1f
- lis r1, init_thread_union@ha
- addi r1, r1, init_thread_union@l
-1: addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
- EXCEPTION_PROLOG_2
- SAVE_NVGPRS(r11)
- addi r3, r1, STACK_FRAME_OVERHEAD
- EXC_XFER_STD(0, stack_overflow_exception)
-#endif
-.endm
-
-#endif /* __HEAD_32_H__ */
+#endif /* __HEAD_40x_H__ */
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_6xx_8xx.h
similarity index 89%
rename from arch/powerpc/kernel/head_32.h
rename to arch/powerpc/kernel/head_6xx_8xx.h
index a2f72c966baf..0e4ce6746443 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_6xx_8xx.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __HEAD_32_H__
-#define __HEAD_32_H__
+#ifndef __HEAD_6xx_8xx_H__
+#define __HEAD_6xx_8xx_H__

#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */

@@ -38,7 +38,7 @@
andi. r11, r11, MSR_PR
.endm

-.macro EXCEPTION_PROLOG_1 for_rtas=0
+.macro EXCEPTION_PROLOG_1
#ifdef CONFIG_VMAP_STACK
mtspr SPRN_SPRG_SCRATCH2,r1
subi r1, r1, INT_FRAME_SIZE /* use r1 if kernel */
@@ -97,16 +97,12 @@
mfspr r12,SPRN_SRR0
mfspr r9,SPRN_SRR1
#endif
-#ifdef CONFIG_40x
- rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
-#else
#ifdef CONFIG_VMAP_STACK
li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
#else
li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */
#endif
mtmsr r10 /* (except for mach check in rtas) */
-#endif
stw r0,GPR0(r11)
lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
addi r10,r10,STACK_FRAME_REGS_MARKER@l
@@ -154,16 +150,12 @@
mfcr r10
rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */
stw r10,_CCR(r11) /* save registers */
-#ifdef CONFIG_40x
- rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
-#else
#ifdef CONFIG_VMAP_STACK
LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */
#else
LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR|MSR_DR)) /* can take exceptions */
#endif
mtmsr r10 /* (except for mach check in rtas) */
-#endif
lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
stw r2,GPR2(r11)
addi r10,r10,STACK_FRAME_REGS_MARKER@l
@@ -177,27 +169,7 @@
addi r11,r1,STACK_FRAME_OVERHEAD
addi r2,r12,-THREAD
stw r11,PT_REGS(r12)
-#if defined(CONFIG_40x)
- /* Check to see if the dbcr0 register is set up to debug. Use the
- internal debug mode bit to do this. */
- lwz r12,THREAD_DBCR0(r12)
- andis. r12,r12,DBCR0_IDM@h
-#endif
ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
-#if defined(CONFIG_40x)
- beq+ 3f
- /* From user and task is ptraced - load up global dbcr0 */
- li r12,-1 /* clear all pending debug events */
- mtspr SPRN_DBSR,r12
- lis r11,global_dbcr0@ha
- tophys(r11,r11)
- addi r11,r11,global_dbcr0@l
- lwz r12,0(r11)
- mtspr SPRN_DBCR0,r12
- lwz r12,4(r11)
- addi r12,r12,-1
- stw r12,4(r11)
-#endif

3:
tovirt_novmstack r2, r2 /* set r2 to current */
@@ -220,9 +192,6 @@
mtspr SPRN_SRR1,r10
mtspr SPRN_SRR0,r11
rfi /* jump to handler, enable MMU */
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
99: b ret_from_kernel_syscall
.endm

@@ -343,4 +312,4 @@
#endif
.endm

-#endif /* __HEAD_32_H__ */
+#endif /* __HEAD_6xx_8xx_H__ */
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 7dce277c8a2a..9124ae889f9f 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -30,7 +30,7 @@
#include <asm/export.h>
#include <asm/code-patching-asm.h>

-#include "head_32.h"
+#include "head_6xx_8xx.h"

.macro compare_to_kernel_boundary scratch, addr
#if CONFIG_TASK_SIZE <= 0x80000000 && CONFIG_PAGE_OFFSET >= 0x80000000
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 0133a02d1d47..ccc691d67b0c 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -32,7 +32,7 @@
#include <asm/export.h>
#include <asm/feature-fixups.h>

-#include "head_32.h"
+#include "head_6xx_8xx.h"

#define LOAD_BAT(n, reg, RA, RB) \
/* see the comment for clear_bats() -- Cort */ \
@@ -272,7 +272,7 @@ MachineCheck:
#endif
bne cr1, 7f
#endif /* CONFIG_PPC_CHRP */
- EXCEPTION_PROLOG_1 for_rtas=1
+ EXCEPTION_PROLOG_1
7: EXCEPTION_PROLOG_2
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_CHRP
--
2.25.0