powerpc/irq: Make alignment & program interrupt behave the same

Alignment was the last user of the ENABLE_INTS macro, which we can
now remove. All non-syscall exceptions now disable interrupts on
entry, they get re-enabled conditionally from C code. Don't
unconditionally re-enable in program check either, check the
original context.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 9 insertions, 10 deletions

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 548da3aa0a30..d58fc4e4149c 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -288,13 +288,6 @@ label##_hv:								\
 /* Exception addition: Hard disable interrupts */
 #define DISABLE_INTS    SOFT_DISABLE_INTS(r10,r11)
 
-/* Exception addition: Keep interrupt state */
-#define ENABLE_INTS                             \
-        ld      r11,PACAKMSR(r13);              \
-        ld      r12,_MSR(r1);                   \
-        rlwimi  r11,r12,0,MSR_EE;               \
-        mtmsrd  r11,1
-
 #define ADD_NVGPRS                              \
         bl      .save_nvgprs
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index cb705fdbb458..8f880bc77c56 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -768,8 +768,8 @@ alignment_common:
         std     r3,_DAR(r1)
         std     r4,_DSISR(r1)
         bl      .save_nvgprs
+        DISABLE_INTS
         addi    r3,r1,STACK_FRAME_OVERHEAD
-        ENABLE_INTS
         bl      .alignment_exception
         b       .ret_from_except
 
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 6aa0c663e247..158972341a2d 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -248,7 +248,7 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
                                    addr, regs->nip, regs->link, code);
         }
 
-        if (!arch_irq_disabled_regs(regs))
+        if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs))
                 local_irq_enable();
 
         memset(&info, 0, sizeof(info));
@@ -1019,7 +1019,9 @@ void __kprobes program_check_exception(struct pt_regs *regs)
                 return;
         }
 
-        local_irq_enable();
+        /* We restore the interrupt state now */
+        if (!arch_irq_disabled_regs(regs))
+                local_irq_enable();
 
 #ifdef CONFIG_MATH_EMULATION
         /* (reason & REASON_ILLEGAL) would be the obvious thing here,
@@ -1069,6 +1071,10 @@ void alignment_exception(struct pt_regs *regs)
 {
         int sig, code, fixed = 0;
 
+        /* We restore the interrupt state now */
+        if (!arch_irq_disabled_regs(regs))
+                local_irq_enable();
+
         /* we don't implement logging of alignment exceptions */
         if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
                 fixed = fix_alignment(regs);