powerpc: Remove misleading DISABLE_INTS

DISABLE_INTS has a long and storied history, but for some time now it
has not actually disabled interrupts.

For the open-coded exception handlers, just stop using it, instead call
RECONCILE_IRQ_STATE directly. This has the benefit of removing a level
of indirection, and making it clear that r10 & r11 are used at that
point.

For the addition case we still need a macro, so rename it to clarify
what it actually does.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 21 insertions, 18 deletions

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 066c15cd2837..13a63379e496 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -513,8 +513,11 @@ label##_relon_hv:							\
  * runlatch, etc...
  */
 
-/* Exception addition: Hard disable interrupts */
-#define DISABLE_INTS    RECONCILE_IRQ_STATE(r10,r11)
+/*
+ * This addition reconciles our actual IRQ state with the various software
+ * flags that track it. This may call C code.
+ */
+#define ADD_RECONCILE   RECONCILE_IRQ_STATE(r10,r11)
 
 #define ADD_NVGPRS                              \
         bl      save_nvgprs
@@ -540,7 +543,7 @@ label##_common:							\
 
 #define STD_EXCEPTION_COMMON(trap, label, hdlr)                 \
         EXCEPTION_COMMON(trap, label, hdlr, ret_from_except,    \
-                         ADD_NVGPRS;DISABLE_INTS)
+                         ADD_NVGPRS;ADD_RECONCILE)
 
 /*
  * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
@@ -549,7 +552,7 @@ label##_common:							\
  */
 #define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr)             \
         EXCEPTION_COMMON(trap, label, hdlr, ret_from_except_lite, \
-                         FINISH_NAP;DISABLE_INTS;RUNLATCH_ON)
+                         FINISH_NAP;ADD_RECONCILE;RUNLATCH_ON)
 
 /*
  * When the idle code in power4_idle puts the CPU into NAP mode,
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 647d6c75ed62..f521b2dac051 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -965,7 +965,7 @@ data_access_common:
         mfspr   r10,SPRN_DSISR
         stw     r10,PACA_EXGEN+EX_DSISR(r13)
         EXCEPTION_PROLOG_COMMON(0x300, PACA_EXGEN)
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         ld      r12,_MSR(r1)
         ld      r3,PACA_EXGEN+EX_DAR(r13)
         lwz     r4,PACA_EXGEN+EX_DSISR(r13)
@@ -981,7 +981,7 @@ h_data_storage_common:
         stw     r10,PACA_EXGEN+EX_DSISR(r13)
         EXCEPTION_PROLOG_COMMON(0xe00, PACA_EXGEN)
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      unknown_exception
         b       ret_from_except
@@ -990,7 +990,7 @@ h_data_storage_common:
         .globl instruction_access_common
 instruction_access_common:
         EXCEPTION_PROLOG_COMMON(0x400, PACA_EXGEN)
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         ld      r12,_MSR(r1)
         ld      r3,_NIP(r1)
         andis.  r4,r12,0x5820
@@ -1054,7 +1054,7 @@ slb_miss_fault:
 
 unrecov_user_slb:
         EXCEPTION_PROLOG_COMMON(0x4200, PACA_EXGEN)
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         bl      save_nvgprs
 1:      addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      unrecoverable_exception
@@ -1077,7 +1077,7 @@ machine_check_common:
         stw     r10,PACA_EXGEN+EX_DSISR(r13)
         EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
         FINISH_NAP
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         ld      r3,PACA_EXGEN+EX_DAR(r13)
         lwz     r4,PACA_EXGEN+EX_DSISR(r13)
         std     r3,_DAR(r1)
@@ -1100,7 +1100,7 @@ alignment_common:
         std     r3,_DAR(r1)
         std     r4,_DSISR(r1)
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      alignment_exception
         b       ret_from_except
@@ -1110,7 +1110,7 @@ alignment_common:
 program_check_common:
         EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN)
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      program_check_exception
         b       ret_from_except
@@ -1121,7 +1121,7 @@ fp_unavailable_common:
         EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)
         bne     1f                      /* if from user, just load it up */
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      kernel_fp_unavailable_exception
         BUG_OPCODE
@@ -1140,7 +1140,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:      /* User process was in a transaction */
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      fp_unavailable_tm
         b       ret_from_except
@@ -1166,7 +1166,7 @@ BEGIN_FTR_SECTION
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:      /* User process was in a transaction */
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      altivec_unavailable_tm
         b       ret_from_except
@@ -1175,7 +1175,7 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      altivec_unavailable_exception
         b       ret_from_except
@@ -1200,7 +1200,7 @@ BEGIN_FTR_SECTION
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 2:      /* User process was in a transaction */
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      vsx_unavailable_tm
         b       ret_from_except
@@ -1209,7 +1209,7 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 #endif
         bl      save_nvgprs
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      vsx_unavailable_exception
         b       ret_from_except
@@ -1468,7 +1468,7 @@ slb_miss_realmode:
 
 unrecov_slb:
         EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
-        DISABLE_INTS
+        RECONCILE_IRQ_STATE(r10, r11)
         bl      save_nvgprs
 1:      addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      unrecoverable_exception