From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f176.google.com (mail-ob0-f176.google.com [209.85.214.176]) by dpdk.org (Postfix) with ESMTP id 0BC27E6D for ; Wed, 10 Feb 2016 13:01:10 +0100 (CET) Received: by mail-ob0-f176.google.com with SMTP id xk3so23477916obc.2 for ; Wed, 10 Feb 2016 04:01:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=LYQxpLcHrFvfIVBj+DZtrKS1bRwNVi1sGnl9sgoMrpM=; b=ofdxlSi01UeQSaeldaerqVLaTbeR13Dm5Ix3mhKoCAaJV09xYg03GBFjKHVWYkHTOE 2u5T+TyuOGeE3OM3K/aDNhr8E7gQgSAKIgvRn96IDDAGVeWH/xjPYUvtoticWjVa3pMS zBzhuwZofKUXPf89zufdyLuhJyejLO+HESTKJ7AcM1A5KMplztEqiZupgZkfesXCPWDK +WZekJW6EL9yGvU3ZYIBuMrJjk+J9ARX4rMG5iqTqrkN53Wypm9QZQUKDiGjyZ4OR59u zu8dIjn4ktb/quhpbOSuUbWnoA3IZ0aGQ6q7WTLg4nIZg5dOCyHZq6vx8jLNSaalBp+/ m12w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type; bh=LYQxpLcHrFvfIVBj+DZtrKS1bRwNVi1sGnl9sgoMrpM=; b=bHVilrkX1f60iciK2zDg9lK0Ry6oSXSTbVys6bYBWvUgqbef+6vcfg7zyGTPkxJYZi 7kpjdsS+5m/Jf4JENd9+hOJKwOzCPSl7giVtZL0UEjTpfpMzlDvRfEgIyXc4ua9ZqwyK 7oDCL9cj87yUTGyq+AVdaJyQyC5DgmDG5owiJfohppPrjmoe6hZHZi780qkUfECe/P/L GOwk3bhaDde1PJtMcub6ZlfdntZ+b3H868YFzCvvr5uHPI/fpVHNnrkKrgRc88vfEKsg Fugx2xLVFBflIHA1yow5AMJXDlSUJ9sHT3EVdiv4FKJ9cZjRk0cXMT9HmHb8i9TtZGEX 96+Q== X-Gm-Message-State: AG10YOQuTHNNZ3VRBC5HRXY486EX7b+QjKQxVoSOmkpC6J8lvuX33aMP4rIyQK6pM8slZAqC7235a9RyIq1xEJXW X-Received: by 10.182.60.170 with SMTP id i10mr36162200obr.62.1455105669525; Wed, 10 Feb 2016 04:01:09 -0800 (PST) MIME-Version: 1.0 Received: by 10.76.180.72 with HTTP; Wed, 10 Feb 2016 04:00:50 -0800 (PST) In-Reply-To: <20160210122333.276ee305@pcviktorin.fit.vutbr.cz> References: <1454076516-21591-1-git-send-email-david.marchand@6wind.com> <1454076516-21591-9-git-send-email-david.marchand@6wind.com> <20160210122333.276ee305@pcviktorin.fit.vutbr.cz> From: David Marchand Date: Wed, 10 Feb 2016 13:00:50 +0100 Message-ID: To: Jan Viktorin Content-Type: text/plain; charset=UTF-8 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH 8/9] pci: add a helper to refresh a device X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Feb 2016 12:01:10 -0000 On Wed, Feb 10, 2016 at 12:23 PM, Jan Viktorin wrote: > On Fri, 29 Jan 2016 15:08:35 +0100 > David Marchand wrote: > >> It will be used mainly for hotplug code. >> >> Signed-off-by: David Marchand >> --- >> lib/librte_eal/bsdapp/eal/eal_pci.c | 49 +++++++++++++++++++++++++++++++++++ >> lib/librte_eal/common/eal_private.h | 13 ++++++++++ >> lib/librte_eal/linuxapp/eal/eal_pci.c | 13 ++++++++++ >> 3 files changed, 75 insertions(+) >> >> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c >> index 4584522..5dd89e3 100644 >> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c >> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c >> @@ -396,6 +396,55 @@ error: >> return -1; >> } >> >> +int >> +pci_refresh_device(const struct rte_pci_addr *addr) > > What about pci_reload_device or pci_reload_device_info? I don't mind > too much, only the word 'refresh' reminds me other associations. Or maybe pci_update_device ? I added pci_add_device in my other pci patchset, so update sounds better to me. >> +{ >> + int fd; >> + struct pci_conf matches[2]; >> + struct pci_match_conf match = { >> + .pc_sel = { >> + .pc_domain = addr->domain, >> + .pc_bus = addr->bus, >> + .pc_dev = addr->devid, >> + .pc_func = addr->function, >> + }, >> + }; >> + struct pci_conf_io conf_io = { >> + .pat_buf_len = 0, >> + .num_patterns = 1, >> + .patterns = { &match }, >> + .match_buf_len = sizeof(matches), >> + .matches = &matches[0], >> + }; >> + >> + fd = open("/dev/pci", O_RDONLY); > > Just courious who provides this special file... is a DPDK-specific > thing? I haven't noticed it anywhere in Linux. I don't know, just took the bsd pci code and plugged myself in it. So for me this is a special bsd device. This is mainly copy/paste. Look at rte_eal_pci_scan() from lib/librte_eal/bsdapp/eal/eal_pci.c. > >> + if (fd < 0) { >> + RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__); >> + goto error; > > If you write: > return -1; > > then you can... > >> + } >> + >> + if (ioctl(fd, PCIOCGETCONF, &conf_io) < 0) { >> + RTE_LOG(ERR, EAL, "%s(): error with ioctl on /dev/pci: %s\n", >> + __func__, strerror(errno)); >> + goto error; >> + } >> + >> + if (conf_io.num_matches != 1) >> + goto error; >> + >> + if (pci_scan_one(fd, &matches[0]) < 0) >> + goto error; >> + >> + close(fd); >> + >> + return 0; >> + >> +error: > > ...remove this if: > >> + if (fd >= 0) >> + close(fd); > > Or, do you consider it more stable in the orignal way? Well, as said above, this is copy/paste code. But, anyway, when I write functions with goto statements, I prefer having a minimal number of return statements, matter of taste. Another way is to add two label error_close: error: but this is a bit overkill here. >> + return -1; >> +} >> + >> /* Read PCI config space. */ >> int rte_eal_pci_read_config(const struct rte_pci_device *dev, >> void *buf, size_t len, off_t offset) >> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h >> index 072e672..ed1903f 100644 >> --- a/lib/librte_eal/common/eal_private.h >> +++ b/lib/librte_eal/common/eal_private.h >> @@ -155,6 +155,19 @@ struct rte_pci_driver; >> struct rte_pci_device; >> >> /** >> + * Refresh a pci device object by asking the kernel for the latest information. >> + * >> + * This function is private to EAL. >> + * >> + * @param addr >> + * The PCI Bus-Device-Function address to look for >> + * @return >> + * - 0 on success. >> + * - negative on error. > > I don't know whether this is a convention in DPDK, anyway, I don't > like to restrict errors to just negatives. You cannot write > > if ((err = pci_refresh_device(...)) /* < 0 */) { > handle_error(err); > } > > as the check for < 0 is required (easy to be avoided). It is a remnant of a lot of code in eal that tries to have 0 for success, < 0 for errors, > 0 for special cases. -- David Marchand