From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:51343 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729336AbeGVRa6 (ORCPT ); Sun, 22 Jul 2018 13:30:58 -0400 Subject: FAILED: patch "[PATCH] powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from" failed to apply to 4.14-stable tree To: ego@linux.vnet.ibm.com, fweimer@redhat.com, mpe@ellerman.id.au Cc: From: Date: Sun, 22 Jul 2018 18:33:43 +0200 Message-ID: <1532277223142142@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From b03897cf318dfc47de33a7ecbc7655584266f034 Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Wed, 18 Jul 2018 14:03:16 +0530 Subject: [PATCH] powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle) On 64-bit servers, SPRN_SPRG3 and its userspace read-only mirror SPRN_USPRG3 are used as userspace VDSO write and read registers respectively. SPRN_SPRG3 is lost when we enter stop4 and above, and is currently not restored. As a result, any read from SPRN_USPRG3 returns zero on an exit from stop4 (Power9 only) and above. Thus in this situation, on POWER9, any call from sched_getcpu() always returns zero, as on powerpc, we call __kernel_getcpu() which relies upon SPRN_USPRG3 to report the CPU and NUMA node information. Fix this by restoring SPRN_SPRG3 on wake up from a deep stop state with the sprg_vdso value that is cached in PACA. Fixes: e1c1cfed5432 ("powerpc/powernv: Save/Restore additional SPRs for stop4 cpuidle") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Florian Weimer Signed-off-by: Gautham R. Shenoy Reviewed-by: Michael Ellerman Signed-off-by: Michael Ellerman diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index e734f6e45abc..689306118b48 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -144,7 +144,9 @@ power9_restore_additional_sprs: mtspr SPRN_MMCR1, r4 ld r3, STOP_MMCR2(r13) + ld r4, PACA_SPRG_VDSO(r13) mtspr SPRN_MMCR2, r3 + mtspr SPRN_SPRG3, r4 blr /*