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Commit 97eb001f authored by Vaidyanathan Srinivasan's avatar Vaidyanathan Srinivasan Committed by Benjamin Herrenschmidt
Browse files

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: default avatarVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: default avatarPreeti U. Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent aca79d2b

arch/powerpc/include/asm/opal.h

+2 −0
Original line number Diff line number Diff line
@@ -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);

arch/powerpc/kernel/exceptions-64s.S

+1 −1
Original line number Diff line number Diff line
@@ -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)

arch/powerpc/kernel/idle_power7.S

+27 −0
Original line number Diff line number Diff line
@@ -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)

arch/powerpc/platforms/powernv/opal-wrappers.S

+1 −0
Original line number Diff line number Diff line
@@ -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);