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 3rwgt80ldkzDrHZ for ; Fri, 22 Jul 2016 16:37:03 +1000 (AEST) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u6M6Y3Fs037478 for ; Fri, 22 Jul 2016 02:37:01 -0400 Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) by mx0a-001b2d01.pphosted.com with ESMTP id 24as6gsbwx-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 22 Jul 2016 02:37:01 -0400 Received: from localhost by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 22 Jul 2016 16:36:57 +1000 Received: from d23relay08.au.ibm.com (d23relay08.au.ibm.com [9.185.71.33]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 2F2972CE8046 for ; Fri, 22 Jul 2016 16:36:56 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay08.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u6M6auWx29622448 for ; Fri, 22 Jul 2016 16:36:56 +1000 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 u6M6atLZ031320 for ; Fri, 22 Jul 2016 16:36:55 +1000 Date: Fri, 22 Jul 2016 16:36:55 +1000 From: Gavin Shan To: Russell Currey Cc: linuxppc-dev@lists.ozlabs.org, gwshan@linux.vnet.ibm.com, benh@kernel.crashing.org Subject: Re: [PATCH] powernv/pci: Add PHB register dump debugfs handle Reply-To: Gavin Shan References: <20160722052336.3340-1-ruscur@russell.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20160722052336.3340-1-ruscur@russell.cc> Message-Id: <20160722063655.GA28438@gwshan> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Jul 22, 2016 at 03:23:36PM +1000, Russell Currey wrote: >On EEH events the kernel will print a dump of relevant registers. >If EEH is unavailable (i.e. CONFIG_EEH is disabled, a new platform >doesn't have EEH support, etc) this information isn't readily available. > >Add a new debugfs handler to trigger a PHB register dump, so that this >information can be made available on demand. > >Signed-off-by: Russell Currey Reviewed-by: Gavin Shan >--- > arch/powerpc/platforms/powernv/pci-ioda.c | 35 +++++++++++++++++++++++++++++++ > 1 file changed, 35 insertions(+) > >diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c >index 891fc4a..ada2f3c 100644 >--- a/arch/powerpc/platforms/powernv/pci-ioda.c >+++ b/arch/powerpc/platforms/powernv/pci-ioda.c >@@ -3018,6 +3018,38 @@ static void pnv_ioda_setup_pe_seg(struct pnv_ioda_pe *pe) > } > } > >+#ifdef CONFIG_DEBUG_FS >+static ssize_t pnv_pci_debug_write(struct file *filp, >+ const char __user *user_buf, >+ size_t count, loff_t *ppos) >+{ >+ struct pci_controller *hose = filp->private_data; >+ struct pnv_phb *phb; >+ int ret = 0; Needn't initialize @ret in advance. The code might be simpler, but it's only a personal preference: struct pci_controller *hose = filp->private_data; struct pnv_phb *phb = hose ? hose->private_data : NULL; if (!phb) return -ENODEV; >+ >+ if (!hose) >+ return -EFAULT; >+ >+ phb = hose->private_data; >+ if (!phb) >+ return -EFAULT; >+ >+ ret = opal_pci_get_phb_diag_data2(phb->opal_id, phb->diag.blob, >+ PNV_PCI_DIAG_BUF_SIZE); >+ >+ if (!ret) >+ pnv_pci_dump_phb_diag_data(phb->hose, phb->diag.blob); >+ >+ return ret < 0 ? ret : count; return ret == OPAL_SUCCESS ? count : -EIO; >+} >+ >+static const struct file_operations pnv_pci_debug_ops = { >+ .open = simple_open, >+ .llseek = no_llseek, >+ .write = pnv_pci_debug_write, It might be reasonable to dump the diag-data on read if it is trying to do it on write. >+}; >+#endif /* CONFIG_DEBUG_FS */ >+ > static void pnv_pci_ioda_create_dbgfs(void) > { > #ifdef CONFIG_DEBUG_FS >@@ -3036,6 +3068,9 @@ static void pnv_pci_ioda_create_dbgfs(void) > if (!phb->dbgfs) > pr_warning("%s: Error on creating debugfs on PHB#%x\n", > __func__, hose->global_number); >+ >+ debugfs_create_file("regdump", 0200, phb->dbgfs, hose, >+ &pnv_pci_debug_ops); "diag-data" might be indicating or a better one you can name :) Thanks, Gavin > } > #endif /* CONFIG_DEBUG_FS */ > } >-- >2.9.0 >