From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id ADC751A0B48 for ; Wed, 12 Nov 2014 13:36:29 +1100 (AEDT) Received: from e23smtp07.au.ibm.com (e23smtp07.au.ibm.com [202.81.31.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 7B6AB140183 for ; Wed, 12 Nov 2014 13:36:29 +1100 (AEDT) Received: from /spool/local by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 12 Nov 2014 12:36:28 +1000 Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 5BE202CE8065 for ; Wed, 12 Nov 2014 13:36:27 +1100 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id sAC2aD6C41418826 for ; Wed, 12 Nov 2014 13:36:13 +1100 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id sAC2aQLc025393 for ; Wed, 12 Nov 2014 13:36:27 +1100 From: Gavin Shan To: linuxppc-dev@ozlabs.org Subject: [PATCH 8/8] powerpc/powernv: Fix potential zero devisor Date: Wed, 12 Nov 2014 13:36:11 +1100 Message-Id: <1415759771-11359-9-git-send-email-gwshan@linux.vnet.ibm.com> In-Reply-To: <1415759771-11359-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1415759771-11359-1-git-send-email-gwshan@linux.vnet.ibm.com> Cc: Gavin Shan List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , If there're no PHBs under P5IOC2 HUB device tree node, we should bail early to avoid zero devisor and allocating TCE tables. Reported-by: Anton Blanchard Signed-off-by: Gavin Shan --- arch/powerpc/platforms/powernv/pci-p5ioc2.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c index 94ce348..3336fcb 100644 --- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c +++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c @@ -196,6 +196,22 @@ void __init pnv_pci_init_p5ioc2_hub(struct device_node *np) hub_id = be64_to_cpup(prop64); pr_info(" HUB-ID : 0x%016llx\n", hub_id); + /* Count child PHBs and calculate TCE space per PHB */ + for_each_child_of_node(np, phbn) { + if (of_device_is_compatible(phbn, "ibm,p5ioc2-pcix") || + of_device_is_compatible(phbn, "ibm,p5ioc2-pciex")) + phb_count++; + } + + if (phb_count <= 0) { + pr_info(" No PHBs for Hub %s\n", np->full_name); + return; + } + + tce_per_phb = __rounddown_pow_of_two(P5IOC2_TCE_MEMORY / phb_count); + pr_info(" Allocating %lld MB of TCE memory per PHB\n", + tce_per_phb >> 20); + /* Currently allocate 16M of TCE memory for every Hub * * XXX TODO: Make it chip local if possible @@ -215,18 +231,6 @@ void __init pnv_pci_init_p5ioc2_hub(struct device_node *np) return; } - /* Count child PHBs */ - for_each_child_of_node(np, phbn) { - if (of_device_is_compatible(phbn, "ibm,p5ioc2-pcix") || - of_device_is_compatible(phbn, "ibm,p5ioc2-pciex")) - phb_count++; - } - - /* Calculate how much TCE space we can give per PHB */ - tce_per_phb = __rounddown_pow_of_two(P5IOC2_TCE_MEMORY / phb_count); - pr_info(" Allocating %lld MB of TCE memory per PHB\n", - tce_per_phb >> 20); - /* Initialize PHBs */ for_each_child_of_node(np, phbn) { if (of_device_is_compatible(phbn, "ibm,p5ioc2-pcix") || -- 1.8.3.2