Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933042AbcKVRgz (ORCPT ); Tue, 22 Nov 2016 12:36:55 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47741 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755406AbcKVRgx (ORCPT ); Tue, 22 Nov 2016 12:36:53 -0500 From: "Gautham R. Shenoy" To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Michael Neuling , Vaidyanathan Srinivasan , "Shreyas B. Prabhu" Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Gautham R. Shenoy" Subject: [PATCH v2] powernv: Handle wakeup from idle due to SRESET Date: Tue, 22 Nov 2016 23:06:32 +0530 X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1479753469-10625-1-git-send-email-ego@linux.vnet.ibm.com> References: <1479753469-10625-1-git-send-email-ego@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16112217-0056-0000-0000-0000020121A0 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006124; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000189; SDB=6.00783960; UDB=6.00378654; IPR=6.00561578; BA=6.00004902; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013408; XFM=3.00000011; UTC=2016-11-22 17:36:51 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16112217-0057-0000-0000-0000063423A8 Message-Id: <1479836192-21233-1-git-send-email-ego@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-11-22_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609300000 definitions=main-1611220308 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2078 Lines: 64 From: "Gautham R. Shenoy" The existing code doesn't handle the case when CPU which was in a hardware-idle state (nap,sleep,winkle on POWER8 and various stop states on POWER9) gets woken up due to a System Reset interrupt. This patch checks if the CPU was woken up due to System Reset, in which case, after restoring the required hardware state, it jumps to the system reset handler. Signed-off-by: Gautham R. Shenoy --- v1 -> v2: Set r9,r11,r12 to CR,SRR0,SRR1 values before jumping to system_reset_common as expected by EXCEPTION_PROLOG_COMMON arch/powerpc/kernel/idle_book3s.S | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 72dac0b..06afe0e 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -353,6 +353,22 @@ ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \ ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \ 20: nop; +#define CHECK_SRESET_INTERRUPT \ +BEGIN_FTR_SECTION_NESTED(67); \ + mfspr r0,SPRN_SRR1; \ + rlwinm r0,r0,45-31,0xf; /* Extract wake reason field (P8,9) */ \ + cmpwi r0,0x4; /* System Reset ? */ \ + bne 21f; \ + ld r1,PACAR1(r13); \ + ld r9,_CCR(r1); \ + ld r11,_NIP(r1); \ + mfspr r12, SPRN_SRR1; \ + b system_reset_common ; \ + b .; /* We shouldn't return here */ \ +FTR_SECTION_ELSE_NESTED(67); \ + nop ; \ +ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 67); \ +21: nop; /* * r3 - requested stop state @@ -644,6 +660,7 @@ _GLOBAL(pnv_wakeup_loss) ld r1,PACAR1(r13) BEGIN_FTR_SECTION CHECK_HMI_INTERRUPT + CHECK_SRESET_INTERRUPT END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) REST_NVGPRS(r1) REST_GPR(2, r1) @@ -666,6 +683,7 @@ _GLOBAL(pnv_wakeup_noloss) bne pnv_wakeup_loss BEGIN_FTR_SECTION CHECK_HMI_INTERRUPT + CHECK_SRESET_INTERRUPT END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) ld r1,PACAR1(r13) ld r6,_CCR(r1) -- 1.8.3.1