[PATCH v5 02/22] powerpc/32: Always enable data translation on syscall entry

Christophe Leroy
2021-02-08T16:10:44Z

If the code can use a stack in vm area, it can also use a
stack in linear space.

Simplify code by removing old non VMAP stack code on PPC32 in syscall.

That means the data translation is now re-enabled early in
syscall entry in all cases, not only when using VMAP stacks.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 23 +----------------------
arch/powerpc/kernel/head_booke.h | 2 --
2 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index a2f72c966baf..fdc07beab844 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -118,7 +118,6 @@
.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
@@ -126,30 +125,16 @@
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 */
+ LOAD_REG_IMMEDIATE(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
- addi r11, r11, THREAD_SIZE - INT_FRAME_SIZE
- tophys(r11, r11)
- 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 */
@@ -157,11 +142,7 @@
#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 */
@@ -190,7 +171,6 @@
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
@@ -200,7 +180,6 @@
#endif

3:
- tovirt_novmstack r2, r2 /* set r2 to current */
lis r11, transfer_to_syscall@h
ori r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index bf33af714d11..706cd9368992 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -144,7 +144,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
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
#ifdef CONFIG_SMP
lwz r10, TASK_CPU(r2)
@@ -158,7 +157,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
stw r12,4(r11)

3:
- tovirt(r2, r2) /* set r2 to current */
lis r11, transfer_to_syscall@h
ori r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
--
2.25.0