linux-kernel - [PATCH V5 5/8] powermgt: Add OPAL call to resync timebase on wakeup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 15 Jan 2014 13:39:29 +0530
From:	Preeti U Murthy <preeti@...ux.vnet.ibm.com>
To:	daniel.lezcano@...aro.org, peterz@...radead.org,
	fweisbec@...il.com, agraf@...e.de, paul.gortmaker@...driver.com,
	paulus@...ba.org, mingo@...nel.org, mikey@...ling.org,
	shangw@...ux.vnet.ibm.com, rafael.j.wysocki@...el.com,
	galak@...nel.crashing.org, benh@...nel.crashing.org,
	paulmck@...ux.vnet.ibm.com, arnd@...db.de,
	linux-pm@...r.kernel.org, rostedt@...dmis.org,
	michael@...erman.id.au, john.stultz@...aro.org, anton@...ba.org,
	tglx@...utronix.de, chenhui.zhao@...escale.com,
	deepthi@...ux.vnet.ibm.com, r58472@...escale.com,
	geoff@...radead.org, linux-kernel@...r.kernel.org,
	srivatsa.bhat@...ux.vnet.ibm.com, schwidefsky@...ibm.com,
	svaidy@...ux.vnet.ibm.com, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH V5 5/8] powermgt: Add OPAL call to resync timebase on wakeup

From: Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>

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@...ux.vnet.ibm.com>
Signed-off-by: Preeti U. Murthy <preeti@...ux.vnet.ibm.com>
---

 arch/powerpc/include/asm/opal.h                |    2 ++
 arch/powerpc/kernel/exceptions-64s.S           |    2 +-
 arch/powerpc/kernel/idle_power7.S              |   27 ++++++++++++++++++++++++
 arch/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 033c06b..a662d06 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -132,6 +132,7 @@ 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
 
 #ifndef __ASSEMBLY__
 
@@ -763,6 +764,7 @@ 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 b8139fb..91e6417 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 e4bbca2..34c71e8 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
 
@@ -124,6 +125,32 @@ _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 e780650..ddfe95a 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -126,3 +126,4 @@ 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);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/