From 97eb001f03494758a938300908b88929163650ce Mon Sep 17 00:00:00 2001 From: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Date: Wed, 26 Feb 2014 05:38:43 +0530 Subject: [PATCH] powerpc/powernv: Add OPAL call to resync timebase on wakeup During "Fast-sleep" and deeper power savings state, decrementer and timebase could be stopped making it out of sync with rest of the cores in the system. Add a firmware call to request platform to resync timebase using low level platform methods. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- arch/powerpc/include/asm/opal.h | 2 ++ arch/powerpc/kernel/exceptions-64s.S | 2 +- arch/powerpc/kernel/idle_power7.S | 27 +++++++++++++++++++ .../powerpc/platforms/powernv/opal-wrappers.S | 1 + 4 files changed, 31 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 40157e2ca6914..c71c72e47d475 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -154,6 +154,7 @@ extern int opal_enter_rtas(struct rtas_args *args, #define OPAL_FLASH_VALIDATE 76 #define OPAL_FLASH_MANAGE 77 #define OPAL_FLASH_UPDATE 78 +#define OPAL_RESYNC_TIMEBASE 79 #define OPAL_GET_MSG 85 #define OPAL_CHECK_ASYNC_COMPLETION 86 #define OPAL_SYNC_HOST_REBOOT 87 @@ -865,6 +866,7 @@ extern void opal_flash_init(void); extern int opal_machine_check(struct pt_regs *regs); extern void opal_shutdown(void); +extern int opal_resync_timebase(void); extern void opal_lpc_init(void); diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index b01a9cb441e45..9533d7a9223c3 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -145,7 +145,7 @@ BEGIN_FTR_SECTION /* Fast Sleep wakeup on PowerNV */ 8: GET_PACA(r13) - b .power7_wakeup_loss + b .power7_wakeup_tb_loss 9: END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206) diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S index 14f78bec62c49..c3ab86975614a 100644 --- a/arch/powerpc/kernel/idle_power7.S +++ b/arch/powerpc/kernel/idle_power7.S @@ -17,6 +17,7 @@ #include <asm/ppc-opcode.h> #include <asm/hw_irq.h> #include <asm/kvm_book3s_asm.h> +#include <asm/opal.h> #undef DEBUG @@ -125,6 +126,32 @@ _GLOBAL(power7_sleep) b power7_powersave_common /* No return */ +_GLOBAL(power7_wakeup_tb_loss) + ld r2,PACATOC(r13); + ld r1,PACAR1(r13) + + /* Time base re-sync */ + li r0,OPAL_RESYNC_TIMEBASE + LOAD_REG_ADDR(r11,opal); + ld r12,8(r11); + ld r2,0(r11); + mtctr r12 + bctrl + + /* TODO: Check r3 for failure */ + + REST_NVGPRS(r1) + REST_GPR(2, r1) + ld r3,_CCR(r1) + ld r4,_MSR(r1) + ld r5,_NIP(r1) + addi r1,r1,INT_FRAME_SIZE + mtcr r3 + mfspr r3,SPRN_SRR1 /* Return SRR1 */ + mtspr SPRN_SRR1,r4 + mtspr SPRN_SRR0,r5 + rfid + _GLOBAL(power7_wakeup_loss) ld r1,PACAR1(r13) REST_NVGPRS(r1) diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index 3e8829c40fbbf..aab54b60334fc 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -126,6 +126,7 @@ OPAL_CALL(opal_return_cpu, OPAL_RETURN_CPU); OPAL_CALL(opal_validate_flash, OPAL_FLASH_VALIDATE); OPAL_CALL(opal_manage_flash, OPAL_FLASH_MANAGE); OPAL_CALL(opal_update_flash, OPAL_FLASH_UPDATE); +OPAL_CALL(opal_resync_timebase, OPAL_RESYNC_TIMEBASE); OPAL_CALL(opal_get_msg, OPAL_GET_MSG); OPAL_CALL(opal_check_completion, OPAL_CHECK_ASYNC_COMPLETION); OPAL_CALL(opal_sync_host_reboot, OPAL_SYNC_HOST_REBOOT); -- 2.30.2