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-rw-r--r--arch/powerpc/kernel/head_64.S49
1 files changed, 48 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index a5ae04a57c7..b7d140430a4 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -376,11 +376,28 @@ label##_common: \
bl hdlr; \
b .ret_from_except
+/*
+ * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
+ * in the idle task and therefore need the special idle handling.
+ */
+#define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr) \
+ .align 7; \
+ .globl label##_common; \
+label##_common: \
+ EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
+ FINISH_NAP; \
+ DISABLE_INTS; \
+ bl .save_nvgprs; \
+ addi r3,r1,STACK_FRAME_OVERHEAD; \
+ bl hdlr; \
+ b .ret_from_except
+
#define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr) \
.align 7; \
.globl label##_common; \
label##_common: \
EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
+ FINISH_NAP; \
DISABLE_INTS; \
bl .ppc64_runlatch_on; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
@@ -388,6 +405,25 @@ label##_common: \
b .ret_from_except_lite
/*
+ * When the idle code in power4_idle puts the CPU into NAP mode,
+ * it has to do so in a loop, and relies on the external interrupt
+ * and decrementer interrupt entry code to get it out of the loop.
+ * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
+ * to signal that it is in the loop and needs help to get out.
+ */
+#ifdef CONFIG_PPC_970_NAP
+#define FINISH_NAP \
+BEGIN_FTR_SECTION \
+ clrrdi r11,r1,THREAD_SHIFT; \
+ ld r9,TI_LOCAL_FLAGS(r11); \
+ andi. r10,r9,_TLF_NAPPING; \
+ bnel power4_fixup_nap; \
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
+#else
+#define FINISH_NAP
+#endif
+
+/*
* Start of pSeries system interrupt routines
*/
. = 0x100
@@ -772,6 +808,7 @@ hardware_interrupt_iSeries_masked:
.globl machine_check_common
machine_check_common:
EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
+ FINISH_NAP
DISABLE_INTS
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -783,7 +820,7 @@ machine_check_common:
STD_EXCEPTION_COMMON(0xb00, trap_0b, .unknown_exception)
STD_EXCEPTION_COMMON(0xd00, single_step, .single_step_exception)
STD_EXCEPTION_COMMON(0xe00, trap_0e, .unknown_exception)
- STD_EXCEPTION_COMMON(0xf00, performance_monitor, .performance_monitor_exception)
+ STD_EXCEPTION_COMMON_IDLE(0xf00, performance_monitor, .performance_monitor_exception)
STD_EXCEPTION_COMMON(0x1300, instruction_breakpoint, .instruction_breakpoint_exception)
#ifdef CONFIG_ALTIVEC
STD_EXCEPTION_COMMON(0x1700, altivec_assist, .altivec_assist_exception)
@@ -1034,6 +1071,7 @@ unrecov_slb:
.globl hardware_interrupt_entry
hardware_interrupt_common:
EXCEPTION_PROLOG_COMMON(0x500, PACA_EXGEN)
+ FINISH_NAP
hardware_interrupt_entry:
DISABLE_INTS
bl .ppc64_runlatch_on
@@ -1041,6 +1079,15 @@ hardware_interrupt_entry:
bl .do_IRQ
b .ret_from_except_lite
+#ifdef CONFIG_PPC_970_NAP
+power4_fixup_nap:
+ andc r9,r9,r10
+ std r9,TI_LOCAL_FLAGS(r11)
+ ld r10,_LINK(r1) /* make idle task do the */
+ std r10,_NIP(r1) /* equivalent of a blr */
+ blr
+#endif
+
.align 7
.globl alignment_common
alignment_common: