2021-06-04 14:55:47

by Christophe Leroy

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Subject: [PATCH 1/4] powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke

To better match booke version of SYSCALL_ENTRY macro, interchange
r10 and r12 in the non booke version.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_32.h | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index a8221ddcbd66..1e55bc054659 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -142,42 +142,42 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)

.macro SYSCALL_ENTRY trapno
mfspr r9, SPRN_SRR1
- mfspr r10, SPRN_SRR0
+ mfspr r12, SPRN_SRR0
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */
- lis r12, 1f@h
- ori r12, r12, 1f@l
+ lis r10, 1f@h
+ ori r10, r10, 1f@l
mtspr SPRN_SRR1, r11
- mtspr SPRN_SRR0, r12
- mfspr r12,SPRN_SPRG_THREAD
+ mtspr SPRN_SRR0, r10
+ mfspr r10,SPRN_SPRG_THREAD
mr r11, r1
- lwz r1,TASK_STACK-THREAD(r12)
- tovirt(r12, r12)
+ lwz r1,TASK_STACK-THREAD(r10)
+ tovirt(r10, r10)
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
rfi
1:
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
- stw r10,_NIP(r11)
- mflr r10
- stw r10, _LINK(r11)
- mfcr r10
- rlwinm r10,r10,0,4,2 /* Clear SO bit in CR */
- stw r10,_CCR(r11) /* save registers */
+ stw r12,_NIP(r11)
+ mflr r12
+ stw r12, _LINK(r11)
+ mfcr r12
+ rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
+ stw r12,_CCR(r11) /* save registers */
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
#endif
- lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
+ lis r12,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
stw r2,GPR2(r11)
- addi r10,r10,STACK_FRAME_REGS_MARKER@l
+ addi r12,r12,STACK_FRAME_REGS_MARKER@l
stw r9,_MSR(r11)
li r2, \trapno
- stw r10,8(r11)
+ stw r12,8(r11)
stw r2,_TRAP(r11)
SAVE_GPR(0, r11)
SAVE_4GPRS(3, r11)
SAVE_2GPRS(7, r11)
- addi r2,r12,-THREAD
+ addi r2,r10,-THREAD
b transfer_to_syscall /* jump to handler */
.endm

--
2.25.0


2021-06-04 14:55:57

by Christophe Leroy

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Subject: [PATCH 2/4] powerpc/32: Interchange r1 and r11 in SYSCALL_ENTRY on booke

To better match non booke version of SYSCALL_ENTRY macro,
interchange r1 and r11 in the booke version.

While at it, in both versions use r1 instead of r11 to save
_NIP and _CCR.

All other uses of r11 will go away in next patch, so don't
bother changing them for now.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_32.h | 4 ++--
arch/powerpc/kernel/head_booke.h | 17 +++++++++--------
2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 1e55bc054659..7ca25eb9bc75 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -158,12 +158,12 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
- stw r12,_NIP(r11)
+ stw r12,_NIP(r1)
mflr r12
stw r12, _LINK(r11)
mfcr r12
rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
- stw r12,_CCR(r11) /* save registers */
+ stw r12,_CCR(r1)
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
#endif
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index f82470091697..4a2fad9f225e 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -135,17 +135,18 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
#endif
mfspr r9, SPRN_SRR1
BOOKE_CLEAR_BTB(r11)
- lwz r11, TASK_STACK - THREAD(r10)
+ mr r11, r1
+ lwz r1, TASK_STACK - THREAD(r10)
rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
- ALLOC_STACK_FRAME(r11, THREAD_SIZE - INT_FRAME_SIZE)
- stw r12, _CCR(r11) /* save various registers */
+ ALLOC_STACK_FRAME(r1, THREAD_SIZE - INT_FRAME_SIZE)
+ stw r12, _CCR(r1)
mflr r12
- stw r12,_LINK(r11)
+ stw r12,_LINK(r1)
mfspr r12,SPRN_SRR0
- stw r1, GPR1(r11)
- stw r1, 0(r11)
- mr r1, r11
- stw r12,_NIP(r11)
+ stw r11, GPR1(r1)
+ stw r11, 0(r1)
+ mr r11, r1
+ stw r12,_NIP(r1)
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
lis r12, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
stw r2,GPR2(r11)
--
2.25.0

2021-06-04 14:56:52

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH 3/4] powerpc/32: Reduce code duplication of system call entry

booke and non booke do pretty similar things in SYSCALL_ENTRY macro
just before calling jumping to transfer_to_syscall().

Do them in transfer_to_syscall() instead.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/entry_32.S | 19 +++++++++++++++++++
arch/powerpc/kernel/head_32.h | 19 -------------------
arch/powerpc/kernel/head_booke.h | 18 ------------------
3 files changed, 19 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9160285cb2f4..0f53f6d11865 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -32,6 +32,7 @@
#include <asm/barrier.h>
#include <asm/kup.h>
#include <asm/bug.h>
+#include <asm/interrupt.h>

#include "head_32.h"

@@ -74,6 +75,24 @@ _ASM_NOKPROBE_SYMBOL(prepare_transfer_to_handler)

.globl transfer_to_syscall
transfer_to_syscall:
+ stw r11, GPR1(r1)
+ stw r11, 0(r1)
+ mflr r12
+ stw r12, _LINK(r1)
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+ rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
+#endif
+ lis r12,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
+ SAVE_GPR(2, r1)
+ addi r12,r12,STACK_FRAME_REGS_MARKER@l
+ stw r9,_MSR(r1)
+ li r2, INTERRUPT_SYSCALL
+ stw r12,8(r1)
+ stw r2,_TRAP(r1)
+ SAVE_GPR(0, r1)
+ SAVE_4GPRS(3, r1)
+ SAVE_2GPRS(7, r1)
+ addi r2,r10,-THREAD
SAVE_NVGPRS(r1)

/* Calling convention has r9 = orig r0, r10 = regs */
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 7ca25eb9bc75..6b1ec9e3541b 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -155,29 +155,10 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
rfi
1:
- stw r11,GPR1(r1)
- stw r11,0(r1)
- mr r11, r1
stw r12,_NIP(r1)
- mflr r12
- stw r12, _LINK(r11)
mfcr r12
rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
stw r12,_CCR(r1)
-#ifdef CONFIG_40x
- rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
-#endif
- lis r12,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
- stw r2,GPR2(r11)
- addi r12,r12,STACK_FRAME_REGS_MARKER@l
- stw r9,_MSR(r11)
- li r2, \trapno
- stw r12,8(r11)
- stw r2,_TRAP(r11)
- SAVE_GPR(0, r11)
- SAVE_4GPRS(3, r11)
- SAVE_2GPRS(7, r11)
- addi r2,r10,-THREAD
b transfer_to_syscall /* jump to handler */
.endm

diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 4a2fad9f225e..10f31146b472 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -140,26 +140,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
ALLOC_STACK_FRAME(r1, THREAD_SIZE - INT_FRAME_SIZE)
stw r12, _CCR(r1)
- mflr r12
- stw r12,_LINK(r1)
mfspr r12,SPRN_SRR0
- stw r11, GPR1(r1)
- stw r11, 0(r1)
- mr r11, r1
stw r12,_NIP(r1)
- rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
- lis r12, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
- stw r2,GPR2(r11)
- addi r12, r12, STACK_FRAME_REGS_MARKER@l
- stw r9,_MSR(r11)
- li r2, \trapno
- stw r12, 8(r11)
- stw r2,_TRAP(r11)
- SAVE_GPR(0, r11)
- SAVE_4GPRS(3, r11)
- SAVE_2GPRS(7, r11)
-
- addi r2,r10,-THREAD
b transfer_to_syscall /* jump to handler */
.endm

--
2.25.0

2021-06-04 14:57:23

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH 4/4] powerpc/32: Avoid #ifdef nested with FTR_SECTION on booke syscall entry

On booke, SYSCALL_ENTRY macro nests an FTR_SECTION with a

Duplicate the single instruction alternative to avoid nesting.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_booke.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 10f31146b472..87b806e8eded 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -128,10 +128,10 @@ BEGIN_FTR_SECTION
mr r12, r13
lwz r13, THREAD_NORMSAVE(2)(r10)
FTR_SECTION_ELSE
-#endif
mfcr r12
-#ifdef CONFIG_KVM_BOOKE_HV
ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
+#else
+ mfcr r12
#endif
mfspr r9, SPRN_SRR1
BOOKE_CLEAR_BTB(r11)
--
2.25.0

2021-06-04 17:12:28

by Andreas Schwab

[permalink] [raw]
Subject: Re: [PATCH 4/4] powerpc/32: Avoid #ifdef nested with FTR_SECTION on booke syscall entry

On Jun 04 2021, Christophe Leroy wrote:

> On booke, SYSCALL_ENTRY macro nests an FTR_SECTION with a

That sentence lacks an

Andreas.

--
Andreas Schwab, [email protected]
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."

2021-06-04 18:32:48

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH 4/4] powerpc/32: Avoid #ifdef nested with FTR_SECTION on booke syscall entry



Le 04/06/2021 à 19:02, Andreas Schwab a écrit :
> On Jun 04 2021, Christophe Leroy wrote:
>
>> On booke, SYSCALL_ENTRY macro nests an FTR_SECTION with a
>
> That sentence lacks an
>


Argh !

It was ..... FTR_SECTION with a
#ifdef CONFIG_KVM_BOOKE_HV.

And git discarded the line starting with a #


Christophe

2021-06-26 10:43:10

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH 1/4] powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke

On Fri, 4 Jun 2021 14:54:12 +0000 (UTC), Christophe Leroy wrote:
> To better match booke version of SYSCALL_ENTRY macro, interchange
> r10 and r12 in the non booke version.

Applied to powerpc/next.

[1/4] powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke
https://git.kernel.org/powerpc/c/10e9252f043ecda0dad7cde6ef87db5d10dff2c7
[2/4] powerpc/32: Interchange r1 and r11 in SYSCALL_ENTRY on booke
https://git.kernel.org/powerpc/c/275dcf24e253f4f5b200bc8cca5eac32a23b08c8
[3/4] powerpc/32: Reduce code duplication of system call entry
https://git.kernel.org/powerpc/c/4bd9e05ac7b8b1f7d0c28702cb684417501a5e39
[4/4] powerpc/32: Avoid #ifdef nested with FTR_SECTION on booke syscall entry
https://git.kernel.org/powerpc/c/a27755d57e0b8c1109a6b1485e52a5f9d51bd4eb

cheers