From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 lists.ozlabs.org (Postfix) with ESMTPS id 9D7C51A1748 for ; Fri, 19 Sep 2014 15:49:23 +1000 (EST) Received: from /spool/local by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 19 Sep 2014 15:49:22 +1000 Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 1B80E2CE8047 for ; Fri, 19 Sep 2014 15:49:20 +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 s8J5oYpx25035000 for ; Fri, 19 Sep 2014 15:50:42 +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 s8J5mlEq017923 for ; Fri, 19 Sep 2014 15:48:47 +1000 From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 1/5] powerpc/eeh: Fix improper condition in eeh_pci_enable() Date: Fri, 19 Sep 2014 15:48:19 +1000 Message-Id: <1411105703-30149-1-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: , The function eeh_pci_enable() is called to apply various requests to one particular PE: Enabling EEH, Disabling EEH, Enabling IO, Enabling DMA, Freezing PE. When enabling IO or DMA on one specific PE, we need check that IO or DMA isn't enabled previously. But the condition used to do the check isn't completely correct because one PE would be in DMA frozen state with workable IO path, or vice versa. The patch fixes the improper condition. Signed-off-by: Gavin Shan --- arch/powerpc/kernel/eeh.c | 58 ++++++++++++++++++++++++++++++++++------------- 1 file changed, 42 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index e436d5e..09bcf95 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -579,25 +579,51 @@ EXPORT_SYMBOL(eeh_check_failure); */ int eeh_pci_enable(struct eeh_pe *pe, int function) { - int rc, flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); + int active_flag, rc; /* * pHyp doesn't allow to enable IO or DMA on unfrozen PE. * Also, it's pointless to enable them on unfrozen PE. So - * we have the check here. + * we have to check before enabling IO or DMA. */ - if (function == EEH_OPT_THAW_MMIO || - function == EEH_OPT_THAW_DMA) { + switch (function) { + case EEH_OPT_THAW_MMIO: + active_flag = EEH_STATE_MMIO_ACTIVE; + break; + case EEH_OPT_THAW_DMA: + active_flag = EEH_STATE_DMA_ACTIVE; + break; + case EEH_OPT_DISABLE: + case EEH_OPT_ENABLE: + case EEH_OPT_FREEZE_PE: + active_flag = 0; + break; + default: + pr_warn("%s: Invalid function %d\n", + __func__, function); + return -EINVAL; + } + + /* + * Check if IO or DMA has been enabled before + * enabling them. + */ + if (active_flag) { rc = eeh_ops->get_state(pe, NULL); if (rc < 0) return rc; - /* Needn't to enable or already enabled */ - if ((rc == EEH_STATE_NOT_SUPPORT) || - ((rc & flags) == flags)) + /* Needn't enable it at all */ + if (rc == EEH_STATE_NOT_SUPPORT) + return 0; + + /* It's already enabled */ + if (rc & active_flag) return 0; } + + /* Issue the request */ rc = eeh_ops->set_option(pe, function); if (rc) pr_warn("%s: Unexpected state change %d on " @@ -605,17 +631,17 @@ int eeh_pci_enable(struct eeh_pe *pe, int function) __func__, function, pe->phb->global_number, pe->addr, rc); - rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); - if (rc <= 0) - return rc; + /* Check if the request is finished successfully */ + if (active_flag) { + rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if (rc <= 0) + return rc; - if ((function == EEH_OPT_THAW_MMIO) && - (rc & EEH_STATE_MMIO_ENABLED)) - return 0; + if (rc & active_flag) + return 0; - if ((function == EEH_OPT_THAW_DMA) && - (rc & EEH_STATE_DMA_ENABLED)) - return 0; + return -EIO; + } return rc; } -- 1.8.3.2