[PATCH v2 12/14] powerpc/32: Enable instruction translation at the same time as data translation
Christophe Leroy
christophe.leroy at csgroup.eu
Fri Jan 22 21:05:35 AEDT 2021
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.
Also update comment in power_save_ppc32_restore().
Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 44 ++++++++++----------------------
arch/powerpc/kernel/head_32.h | 39 ++++++++++++----------------
arch/powerpc/kernel/head_40x.S | 10 +++++---
arch/powerpc/kernel/head_booke.h | 7 ++---
4 files changed, 39 insertions(+), 61 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 8a0e5885b731..6e70c6fdfe8a 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -198,12 +198,8 @@ 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
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* When tracing IRQ state (lockdep) we enable the MMU before we call
@@ -219,13 +215,9 @@ transfer_to_handler_cont:
/* MSR isn't changing, just transition directly */
#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
@@ -245,21 +237,7 @@ _ASM_NOKPROBE_SYMBOL(transfer_to_handler)
_ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
#ifdef CONFIG_TRACE_IRQFLAGS
-1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to
- * keep interrupts disabled at this point otherwise we might risk
- * taking an interrupt before we tell lockdep they are enabled.
- */
- lis r12,reenable_mmu at h
- ori r12,r12,reenable_mmu at l
- LOAD_REG_IMMEDIATE(r0, MSR_KERNEL)
- mtspr SPRN_SRR0,r12
- mtspr SPRN_SRR1,r0
- rfi
-#ifdef CONFIG_40x
- b . /* Prevent prefetch past rfi */
-#endif
-
-reenable_mmu:
+1:
/*
* We save a bunch of GPRs,
* r3 can be different from GPR3(r1) at this point, r9 and r11
@@ -1334,16 +1312,20 @@ _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 at h
+ ori r8, r8, 1f at 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 5ba4c6391107..7209e63db366 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -57,10 +57,14 @@
.endm
.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
- 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 at h
+ ori r11, r11, 1f at l
+ mtspr SPRN_SRR0, r11
mfspr r11, SPRN_SPRG_SCRATCH2
+ rfi
+1:
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
@@ -86,7 +90,7 @@
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
#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)
@@ -107,9 +111,13 @@
lwz r1,TASK_STACK-THREAD(r12)
beq- 99f
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
- mtmsr r10
- isync
+ LOAD_REG_IMMEDIATE(r10, MSR_KERNEL) /* can take exceptions */
+ mtspr SPRN_SRR1, r10
+ lis r10, 1f at h
+ ori r10, r10, 1f at l
+ mtspr SPRN_SRR0, r10
+ rfi
+1:
tovirt(r12, r12)
stw r11,GPR1(r1)
stw r11,0(r1)
@@ -123,9 +131,6 @@
stw r10,_CCR(r11) /* save registers */
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
-#else
- LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */
- mtmsr r10 /* (except for mach check in rtas) */
#endif
lis r10,STACK_FRAME_REGS_MARKER at ha /* exception frame marker */
stw r2,GPR2(r11)
@@ -162,8 +167,6 @@
#endif
3:
- lis r11, transfer_to_syscall at h
- ori r11, r11, transfer_to_syscall at l
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* If MSR is changing we need to keep interrupts disabled at this point
@@ -175,15 +178,8 @@
#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
+ mtmsr r10
+ b transfer_to_syscall /* jump to handler */
99: b ret_from_kernel_syscall
.endm
@@ -220,7 +216,6 @@
#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 6b23cbd7f9c5..96ec800ebf7f 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -128,9 +128,13 @@ _ENTRY(saved_ksp_limit)
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
1: stw r1,crit_r1 at 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 at h
+ ori r11, r11, 1f at l
+ mtspr SPRN_SRR0, r11
+ rfi
+1:
lwz r11,crit_r1 at 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 5d0402c48ebc..2e3cb1cc42fb 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -157,8 +157,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
stw r12,4(r11)
3:
- lis r11, transfer_to_syscall at h
- ori r11, r11, transfer_to_syscall at l
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* If MSR is changing we need to keep interrupts disabled at this point
@@ -172,9 +170,8 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
lis r10, (MSR_KERNEL | MSR_EE)@h
ori r10, r10, (MSR_KERNEL | MSR_EE)@l
#endif
- mtspr SPRN_SRR1,r10
- mtspr SPRN_SRR0,r11
- rfi /* jump to handler, enable MMU */
+ mtmsr r10
+ b transfer_to_syscall /* jump to handler */
99: b ret_from_kernel_syscall
.endm
--
2.25.0
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