powerpc/32: Always enable data translation on syscall entry

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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/412c6c1786922d991bbb89c2ad2e82cffe8ab112.1612796617.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index abc7b603ab65c3d0985211b22d675c411c5905f0..d481e351f006832063e9444f7b8d530d6cb672a5 100644 (file)
--- 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 bf33af714d1149d5ca507ab834e7afdbf931eb0c..706cd93689925fa23923edd9b49a821fd22959c1 100644 (file)
--- 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