powerpc/irq: Make alignment & program interrupt behave the same
Benjamin Herrenschmidt [Tue, 8 May 2012 03:38:50 +0000 (13:38 +1000)]
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>

arch/powerpc/include/asm/exception-64s.h
arch/powerpc/kernel/exceptions-64s.S
arch/powerpc/kernel/traps.c

index 548da3a..d58fc4e 100644 (file)
@@ -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
 
index cb705fd..8f880bc 100644 (file)
@@ -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
 
index 6aa0c66..1589723 100644 (file)
@@ -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);