From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp06.au.ibm.com (e23smtp06.au.ibm.com [202.81.31.148]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3r52tp4VhBzDqBx for ; Thu, 12 May 2016 16:21:22 +1000 (AEST) Received: from localhost by e23smtp06.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 12 May 2016 16:21:21 +1000 Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 1EDA12BB0054 for ; Thu, 12 May 2016 16:21:14 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u4C6KabU59965584 for ; Thu, 12 May 2016 16:20:58 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u4C6Jwrx004788 for ; Thu, 12 May 2016 16:19:58 +1000 Date: Thu, 12 May 2016 16:09:25 +1000 From: Gavin Shan To: Alexey Kardashevskiy Cc: linuxppc-dev@lists.ozlabs.org, Alistair Popple , Gavin Shan , Michael Ellerman , Paul Mackerras Subject: Re: [PATCH kernel 1/2] powerpc/powernv: Fix insufficient memory allocation Message-ID: <20160512060925.GA3167@gwshan> Reply-To: Gavin Shan References: <1463032030-38974-1-git-send-email-aik@ozlabs.ru> <1463032030-38974-2-git-send-email-aik@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1463032030-38974-2-git-send-email-aik@ozlabs.ru> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, May 12, 2016 at 03:47:09PM +1000, Alexey Kardashevskiy wrote: >The pnv_pci_init_ioda_phb() helper allocates a blob to store auxilary >data such PE and M32/M64 segment allocation maps; this single blob has few >partitions, size of each is derived from the PE number - >phb->ioda.total_pe_num. > >It was assumed that the minimum PE number is 8, however it is 4 for NPU >so the pe_alloc part was missing in the allocated blob. >It was invisible till recently as we were not tracking used M64 segments >and NPUs do not use M32 segments so the phb->ioda.m32_segmap >(which was pointing to the same address as phb->ioda.pe_alloc) >has never been written to leaving the pe_alloc memory intact. > >After 401203ac2d "powerpc/powernv: Track M64 segment consumption" >the pe_alloc gets corrupted and PE allocation cannot work. >This fixes the issue by enforcing the minimum PE number to 8. > As I said offline yesterday, the issue exists from day-1 when NPU PHB is supported. I don't think it's related to 401203ac2d. Without the logic tracking M64 segments, the PE# bitmap still can be corrupted when writting to M32 segment map. It's confusing to mention a unrelated commit in the changelog. Since the issue exists from day-1 when NPU PHB is supported, is a stable tag needed? >Signed-off-by: Alexey Kardashevskiy With above parts fixed: Reviewed-by: Gavin Shan >--- > arch/powerpc/platforms/powernv/pci-ioda.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > >diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c >index 6cda2a8..d0d32c2 100644 >--- a/arch/powerpc/platforms/powernv/pci-ioda.c >+++ b/arch/powerpc/platforms/powernv/pci-ioda.c >@@ -3507,7 +3507,8 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np, > PNV_IODA1_DMA32_SEGSIZE; > > /* Allocate aux data & arrays. We don't have IO ports on PHB3 */ >- size = _ALIGN_UP(phb->ioda.total_pe_num / 8, sizeof(unsigned long)); >+ size = _ALIGN_UP(max_t(unsigned, phb->ioda.total_pe_num, 8) / 8, >+ sizeof(unsigned long)); > m64map_off = size; > size += phb->ioda.total_pe_num * sizeof(phb->ioda.m64_segmap[0]); > m32map_off = size; >-- >2.5.0.rc3 >