powerpc/32: Enable instruction translation at the same time as data translation

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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5269c7e5f5d2117358af3a89744d75a116be27b0.1615552867.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 33e9703..01a064c 100644 (file)
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -153,19 +153,11 @@ 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 910f866..88b02bd 100644 (file)
--- 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 @@ label:
 #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 7da673e..55fa99c 100644 (file)
--- 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 4a5f0c9..f712b9b 100644 (file)
--- 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 @@ label:
 #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