powernv:idle: Add IDLE_STATE_ENTER_SEQ_NORET macro

Currently all the low-power idle states are expected to wake up
at reset vector 0x100. Which is why the macro IDLE_STATE_ENTER_SEQ
that puts the CPU to an idle state and never returns.

On ISA v3.0, when the ESL and EC bits in the PSSCR are zero, the CPU
is expected to wake up at the next instruction of the idle
instruction.

This patch adds a new macro named IDLE_STATE_ENTER_SEQ_NORET for the
no-return variant and reuses the name IDLE_STATE_ENTER_SEQ
for a variant that allows resuming operation at the instruction next
to the idle-instruction.

Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h
index 3919332..0a3255b 100644 (file)
--- a/arch/powerpc/include/asm/cpuidle.h
+++ b/arch/powerpc/include/asm/cpuidle.h
@@ -21,7 +21,7 @@ extern u64 pnv_first_deep_stop_state;
 
 /* Idle state entry routines */
 #ifdef CONFIG_PPC_P7_NAP
-#define        IDLE_STATE_ENTER_SEQ(IDLE_INST)                         \
+#define IDLE_STATE_ENTER_SEQ(IDLE_INST)                         \
        /* Magic NAP/SLEEP/WINKLE mode enter sequence */        \
        std     r0,0(r1);                                       \
        ptesync;                                                \
@@ -29,6 +29,9 @@ extern u64 pnv_first_deep_stop_state;
 1:     cmpd    cr0,r0,r0;                                      \
        bne     1b;                                             \
        IDLE_INST;                                              \
+
+#define        IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST)                   \
+       IDLE_STATE_ENTER_SEQ(IDLE_INST)                         \
        b       .
 #endif /* CONFIG_PPC_P7_NAP */
 

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index d39d611..069aac8 100644 (file)
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -381,12 +381,12 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
        lbz     r3,PACA_THREAD_IDLE_STATE(r13)
        cmpwi   r3,PNV_THREAD_NAP
        bgt     10f
-       IDLE_STATE_ENTER_SEQ(PPC_NAP)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP)
        /* No return */
 10:
        cmpwi   r3,PNV_THREAD_SLEEP
        bgt     2f
-       IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
        /* No return */
 
 2:
@@ -400,7 +400,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
         */
        ori     r13,r13,1
        SET_PACA(r13)
-       IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
        /* No return */
 4:
 #endif

diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 72dac0b..be90e2f 100644 (file)
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -205,7 +205,7 @@ pnv_enter_arch207_idle_mode:
        stb     r3,PACA_THREAD_IDLE_STATE(r13)
        cmpwi   cr3,r3,PNV_THREAD_SLEEP
        bge     cr3,2f
-       IDLE_STATE_ENTER_SEQ(PPC_NAP)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP)
        /* No return */
 2:
        /* Sleep or winkle */
@@ -239,7 +239,7 @@ pnv_fastsleep_workaround_at_entry:
 
 common_enter: /* common code for all the threads entering sleep or winkle */
        bgt     cr3,enter_winkle
-       IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
 
 fastsleep_workaround_at_entry:
        ori     r15,r15,PNV_CORE_IDLE_LOCK_BIT
@@ -261,7 +261,7 @@ fastsleep_workaround_at_entry:
 enter_winkle:
        bl      save_sprs_to_stack
 
-       IDLE_STATE_ENTER_SEQ(PPC_WINKLE)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
 
 /*
  * r3 - requested stop state
@@ -280,7 +280,7 @@ power_enter_stop:
        ld      r4,ADDROFF(pnv_first_deep_stop_state)(r5)
        cmpd    r3,r4
        bge     2f
-       IDLE_STATE_ENTER_SEQ(PPC_STOP)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_STOP)
 2:
 /*
  * Entering deep idle state.
@@ -302,7 +302,7 @@ lwarx_loop_stop:
 
        bl      save_sprs_to_stack
 
-       IDLE_STATE_ENTER_SEQ(PPC_STOP)
+       IDLE_STATE_ENTER_SEQ_NORET(PPC_STOP)
 
 _GLOBAL(power7_idle)
        /* Now check if user or arch enabled NAP mode */