From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jincheng Miao Subject: Re: [PATCH v2 1/2] igb_uio: compatible with upstream longterm kernel and RHEL6 Date: Fri, 28 Nov 2014 16:13:41 +0800 Message-ID: <54782EB5.7060409@redhat.com> References: <1414741039-3531-1-git-send-email-jmiao@redhat.com> <1414741039-3531-2-git-send-email-jmiao@redhat.com> <7579030.6nSHmmQ36o@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable Cc: dev-VfR2kkLFssw@public.gmane.org To: Thomas Monjalon Return-path: In-Reply-To: <7579030.6nSHmmQ36o@xps13> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On 11/28/2014 01:01 AM, Thomas Monjalon wrote: > 2014-10-31 15:37, Jincheng Miao: >> Function pci_num_vf() is introduced from upstream linux-2.6.34. So >> this patch make compatible with longterm kernel linux-2.6.32.63. >> >> For RHEL6's kernel, although it is based on linux-2.6.32, it has >> pci_num_vf() implementation. As the same with commit 11ba0426, >> pci_num_vf() is defined from RHEL6. So we should check the macro >> RHEL_RELEASE_CODE to consider this situation. > Please, could you explain in which case CONFIG_PCI_IOV is defined? > The logic is a bit difficult to understand. Yep, there is a little confusion for pci_num_vf(): 1. it is available when CONFIG_PCI_IOV is defined. 2. it is introduced from upstream kernel v2.6.34 (fb8a0d9) 3. it is implemented from RHEL6.0, although the kernel version is 2.6.32. The logic of this patch is: #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) && \ (!(defined(RHEL_RELEASE_CODE) && RHEL_RELEASE_CODE >=3D=20 RHEL_RELEASE_VERSION(6, 0) && defined(CONFIG_PCI_IOV))) Firstly it detects kernel version, if it is less than 2.6.34, and it is=20 not RHEL-specified, then define pci_num_vf(). Secondly, it deals with RHEL-specified. If it is RHEL6.0 or later, and=20 CONFIG_PCI_IOV is defined. we should not define pci_num_vf(). If any of=20 these conditions is not reached, pci_num_vf() should be defined. Some days ago, I setup dpdk for longterm kernel 2.6.32.63, and got error: ``` CC [M]=20 /root/dpdk-source/build/build/lib/librte_eal/linuxapp/igb_uio/igb_uio.o /root/dpdk-source/build/build/lib/librte_eal/linuxapp/igb_uio/igb_uio.c:=20 In function =91show_max_vfs=92: /root/dpdk-source/build/build/lib/librte_eal/linuxapp/igb_uio/igb_uio.c:7= 5:=20 error: implicit declaration of function =91pci_num_vf=92 ``` This problem is introduced by commit 11ba04265 commit 11ba04265cfd2a53c12c030fcaa5dfe7eed39a42 Author: Guillaume Gaudonville Date: Wed Sep 3 10:18:23 2014 +0200 igb_uio: fix build on RHEL 6.3 - pci_num_vf() is already defined in RHEL 6 - pci_intx_mask_supported is already defined in RHEL 6.3 - pci_check_and_mask_intx is already defined in RHEL 6.3 Signed-off-by: Guillaume Gaudonville Signed-off-by: David Marchand Signed-off-by: Thomas Monjalon +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) && \ + !defined(CONFIG_PCI_IOV) That is because longterm kernel 2.6.32.63 defined CONFIG_PCI_IOV, but it=20 lacks pci_num_vf(), after above processing, pci_num_vf() is still not existed, then build fai= l. My patch could work around it, and can deal with RHEL-specified kernel. >> #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) && \ >> - !defined(CONFIG_PCI_IOV) >> + (!(defined(RHEL_RELEASE_CODE) && \ >> + RHEL_RELEASE_CODE >=3D RHEL_RELEASE_VERSION(6, 0) && \ >> + defined(CONFIG_PCI_IOV))) >> =20 >> static int pci_num_vf(struct pci_dev *dev) >> {