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Subject[RFC PATCH v1 15/41] powerpc/32: Enable instruction translation at the same time as data translation
Date
On 40x and 8xx, kernel text is pinned.
On book3s/32, kernel text is mapped by BATs.

Enable instruction translation at the same time as data translation, it
makes things simpler.

In syscall handler, MSR_RI can also be set at the same time because
srr0/srr1 are already saved and r1 is set properly.

On booke, translation is always on, so at the end all PPC32
have translation on early. Just update msr.

Also update comment in power_save_ppc32_restore().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 30 ++++++++++++------------------
arch/powerpc/kernel/head_32.h | 13 ++++++++-----
arch/powerpc/kernel/head_40x.S | 10 +++++++---
arch/powerpc/kernel/head_booke.h | 6 ++++--
4 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0b6af35acdfd..f244e7846031 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -154,19 +154,11 @@ transfer_to_handler:
transfer_to_handler_cont:
3:
mflr r9
- tovirt(r9, r9)
lwz r11,0(r9) /* virtual address of handler */
lwz r9,4(r9) /* where to go when done */
-#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
- mtspr SPRN_NRI, r0
-#endif
- mtspr SPRN_SRR0,r11
- mtspr SPRN_SRR1,r10
+ mtctr r11
mtlr r9
- rfi /* jump to handler, enable MMU */
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
+ bctr /* jump to handler */

#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
4: rlwinm r12,r12,0,~_TLF_NAPPING
@@ -444,8 +436,6 @@ fee_restarts:
li r10,-1
stw r10,_TRAP(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
- lis r10,MSR_KERNEL@h
- ori r10,r10,MSR_KERNEL@l
bl transfer_to_handler_full
.long unrecoverable_exception
.long ret_from_except
@@ -945,16 +935,20 @@ _GLOBAL(enter_rtas)
mtspr SPRN_SRR1,r9
rfi
1:
- li r0, MSR_KERNEL & ~MSR_IR /* can take DTLB miss */
- mtmsr r0
- isync
+ lis r8, 1f@h
+ ori r8, r8, 1f@l
+ LOAD_REG_IMMEDIATE(r9,MSR_KERNEL)
+ mtspr SPRN_SRR0,r8
+ mtspr SPRN_SRR1,r9
+ rfi /* Reactivate MMU translation */
+1:
lwz r8,INT_FRAME_SIZE+4(r1) /* get return address */
lwz r9,8(r1) /* original msr value */
addi r1,r1,INT_FRAME_SIZE
li r0,0
stw r0, THREAD + RTAS_SP(r2)
- mtspr SPRN_SRR0,r8
- mtspr SPRN_SRR1,r9
- rfi /* return to caller */
+ mtlr r8
+ mtmsr r9
+ blr /* return to caller */
_ASM_NOKPROBE_SYMBOL(enter_rtas)
#endif /* CONFIG_PPC_RTAS */
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 910f86642eec..88b02bd91e8e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -63,10 +63,14 @@
mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
.endif
#endif
- LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
- mtmsr r11
- isync
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~MSR_RI) /* re-enable MMU */
+ mtspr SPRN_SRR1, r11
+ lis r11, 1f@h
+ ori r11, r11, 1f@l
+ mtspr SPRN_SRR0, r11
mfspr r11, SPRN_SPRG_SCRATCH2
+ rfi
+1:
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
@@ -94,7 +98,7 @@
#elif defined(CONFIG_PPC_8xx)
mtspr SPRN_EID, r2 /* Set MSR_RI */
#else
- li r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
+ li r10, MSR_KERNEL /* can take exceptions */
mtmsr r10 /* (except for mach check in rtas) */
#endif
stw r0,GPR0(r11)
@@ -179,7 +183,6 @@
#define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret) \
li r10,trap; \
stw r10,_TRAP(r11); \
- LOAD_REG_IMMEDIATE(r10, msr); \
bl tfer; \
.long hdlr; \
.long ret
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 7da673ec63ef..55fa99c5085c 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -126,9 +126,13 @@ _ENTRY(crit_esr)
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
1: stw r1,crit_r1@l(0)
addi r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
- LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
- mtmsr r11
- isync
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)) /* re-enable MMU */
+ mtspr SPRN_SRR1, r11
+ lis r11, 1f@h
+ ori r11, r11, 1f@l
+ mtspr SPRN_SRR0, r11
+ rfi
+1:
lwz r11,crit_r1@l(0)
stw r11,GPR1(r1)
stw r11,0(r1)
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 4a5f0c9b652b..ff93ed519b3b 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -53,6 +53,8 @@ END_BTB_FLUSH_SECTION
mfspr r11, SPRN_SRR1; \
DO_KVM BOOKE_INTERRUPT_##intno SPRN_SRR1; \
andi. r11, r11, MSR_PR; /* check whether user or kernel */\
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) \
+ mtmsr r11 \
mr r11, r1; \
beq 1f; \
BOOKE_CLEAR_BTB(r11) \
@@ -192,6 +194,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
DO_KVM BOOKE_INTERRUPT_##intno exc_level_srr1; \
BOOKE_CLEAR_BTB(r10) \
andi. r11,r11,MSR_PR; \
+ LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)) \
+ mtmsr r11 \
mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
lwz r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\
@@ -282,8 +286,6 @@ 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); \
- lis r10,msr@h; \
- ori r10,r10,msr@l; \
bl tfer; \
.long hdlr; \
.long ret
--
2.25.0
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