From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp03.au.ibm.com (e23smtp03.au.ibm.com [202.81.31.145]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id EE1B01A0835 for ; Thu, 25 Sep 2014 14:48:00 +1000 (EST) Received: from /spool/local by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 25 Sep 2014 14:47:57 +1000 Received: from d23relay05.au.ibm.com (d23relay05.au.ibm.com [9.190.235.152]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 1F7EF2CE8047 for ; Thu, 25 Sep 2014 14:47:56 +1000 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay05.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s8P4NkLC31785008 for ; Thu, 25 Sep 2014 14:23:47 +1000 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s8P4lsX0014023 for ; Thu, 25 Sep 2014 14:47:55 +1000 Date: Thu, 25 Sep 2014 14:47:54 +1000 From: Gavin Shan To: Michael Ellerman Subject: Re: [2/5] powerpc/eeh: Add eeh_pe_state sysfs entry Message-ID: <20140925044754.GA11163@shangw> Reply-To: Gavin Shan References: <1408244549-10221-3-git-send-email-gwshan@linux.vnet.ibm.com> <20140925040958.4D2C414016A@ozlabs.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140925040958.4D2C414016A@ozlabs.org> Cc: linuxppc-dev@lists.ozlabs.org, Gavin Shan List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Sep 25, 2014 at 02:09:58PM +1000, Michael Ellerman wrote: >On Sun, 2014-17-08 at 03:02:26 UTC, Gavin Shan wrote: >> The patch adds sysfs entry "eeh_pe_state". Reading on it returns >> the PE's state while writing to it clears the frozen state. It's >> used to check or clear the PE frozen state from userland for >> debugging purpose. >> >> diff --git a/arch/powerpc/kernel/eeh_sysfs.c b/arch/powerpc/kernel/eeh_sysfs.c >> index e2595ba..e69bcbb 100644 >> --- a/arch/powerpc/kernel/eeh_sysfs.c >> +++ b/arch/powerpc/kernel/eeh_sysfs.c >> @@ -54,6 +54,63 @@ EEH_SHOW_ATTR(eeh_mode, mode, "0x%x"); >> EEH_SHOW_ATTR(eeh_config_addr, config_addr, "0x%x"); >> EEH_SHOW_ATTR(eeh_pe_config_addr, pe_config_addr, "0x%x"); >> >> +static ssize_t eeh_pe_state_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + struct pci_dev *pdev = to_pci_dev(dev); >> + struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev); >> + int state; >> + >> + if (!edev || !edev->pe) >> + return 0; >> + >> + state = eeh_ops->get_state(edev->pe, NULL); >> + return sprintf(buf, "PHB#%d-PE#%d: 0x%08x 0x%08x\n", >> + edev->pe->phb->global_number, >> + edev->pe->addr, state, edev->pe->state); > >Shouldn't this only display the state, ie not the number and addr etc. > Yes, I'll remove PHB#%d-PE#%d in next revision. Another sysfs entry gives the PE number: /sys/bus/pci/devices/xxxx:xx:xx.x/eeh_pe_config_addr >And why are there two states, state and edev->pe->state ? > state is from hardware, edev->pe->state is software maintained state. >> +static ssize_t eeh_pe_state_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + struct pci_dev *pdev = to_pci_dev(dev); >> + struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev); >> + int ret; >> + >> + if (!edev || !edev->pe) >> + return 0; > >Shouldn't that be an error? > >> + /* Nothing to do if it's not frozen */ >> + if (!(edev->pe->state & EEH_PE_ISOLATED)) >> + return 0; >> + >> + /* Enable MMIO */ >> + ret = eeh_pci_enable(edev->pe, EEH_OPT_THAW_MMIO); >> + if (ret) { >> + pr_warn("%s: Failure %d enabling MMIO for PHB#%d-PE#%d\n", >> + __func__, ret, edev->pe->phb->global_number, >> + edev->pe->addr); >> + return 0; > >Error ? > >> + } >> + >> + /* Enable DMA */ >> + ret = eeh_pci_enable(edev->pe, EEH_OPT_THAW_DMA); >> + if (ret) { >> + pr_warn("%s: Failure %d enabling DMA for PHB#%d-PE#%d\n", >> + __func__, ret, edev->pe->phb->global_number, >> + edev->pe->addr); >> + return 0; > >Error? > Yes, I'll fix all "Error" cases. >And should it roll back, ie. unthaw MMIO? > It's not necessary as it's only for debugging purpose. The main purpose is to keep dumping the PE hardware/software state when recovering one specific PE. Thanks, Gavin