From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3ydnTZ585WzDrRg for ; Sat, 18 Nov 2017 05:59:14 +1100 (AEDT) Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vAHIsBVg001560 for ; Fri, 17 Nov 2017 13:59:11 -0500 Received: from e12.ny.us.ibm.com (e12.ny.us.ibm.com [129.33.205.202]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ea4hgtn1t-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 17 Nov 2017 13:59:11 -0500 Received: from localhost by e12.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 17 Nov 2017 13:59:10 -0500 From: "Guilherme G. Piccoli" To: linuxppc-dev@lists.ozlabs.org Cc: gpiccoli@linux.vnet.ibm.com, paulus@samba.org, mpe@ellerman.id.au, benh@kernel.crashing.org, bsingharora@gmail.com Subject: [PATCH v3] powerpc/powernv: Add ppc_pci_reset_phbs parameter to issue a PHB reset Date: Fri, 17 Nov 2017 16:58:59 -0200 Message-Id: <20171117185859.2756-1-gpiccoli@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , During a kdump kernel boot in PowerPC, we request a reset of the PHBs to the FW. It makes sense, since if we are booting a kdump kernel it means we had some trouble before and we cannot rely in the adapters' health; they could be in a bad state, hence the reset is needed. But this reset is useful not only in kdump - there are situations, specially when debugging drivers, that we could break an adapter in a way it requires such reset. One can tell to just go ahead and reboot the machine, but happens that many times doing kexec is much faster, and so preferable than a full power cycle. This patch adds the ppc_pci_reset_phbs parameter to perform such reset. Signed-off-by: Guilherme G. Piccoli --- * v3: Changed parameter name, adding prefix "ppc_" [mpe suggestion] arch/powerpc/platforms/powernv/pci-ioda.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index fb5cd7511189..19f1b0021585 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -89,6 +89,7 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level, } static bool pnv_iommu_bypass_disabled __read_mostly; +static bool pci_reset_phbs __read_mostly; static int __init iommu_setup(char *str) { @@ -110,6 +111,14 @@ static int __init iommu_setup(char *str) } early_param("iommu", iommu_setup); +static int __init pci_reset_phbs_setup(char *str) +{ + pci_reset_phbs = true; + return 0; +} + +early_param("ppc_pci_reset_phbs", pci_reset_phbs_setup); + static inline bool pnv_pci_is_m64(struct pnv_phb *phb, struct resource *r) { /* @@ -4014,9 +4023,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np, * If we're running in kdump kernel, the previous kernel never * shutdown PCI devices correctly. We already got IODA table * cleaned out. So we have to issue PHB reset to stop all PCI - * transactions from previous kernel. + * transactions from previous kernel. The ppc_pci_reset_phbs + * kernel parameter will force this reset too. */ - if (is_kdump_kernel()) { + if (is_kdump_kernel() || pci_reset_phbs) { pr_info(" Issue PHB reset ...\n"); pnv_eeh_phb_reset(hose, EEH_RESET_FUNDAMENTAL); pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE); -- 2.15.0.rc0