From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jianbo Liu <jianbo.liu@linaro.org>
Subject: Re: [PATCH v1 03/28] eal/linux: extract function
	rte_eal_unbind_kernel_driver
Date: Fri, 13 May 2016 09:22:23 +0800
Message-ID: <CAP4Qi3__gh2-B0W4ePjAUJbnHyxJvXx0+x1F-ZBXqCoZgCn8Eg@mail.gmail.com>
References: <1451682326-5834-1-git-send-email-viktorin@rehivetech.com>
 <1462542490-15556-1-git-send-email-viktorin@rehivetech.com>
 <1462542490-15556-4-git-send-email-viktorin@rehivetech.com>
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Cc: dev@dpdk.org, David Marchand <david.marchand@6wind.com>,
 Thomas Monjalon <thomas.monjalon@6wind.com>,
 Bruce Richardson <bruce.richardson@intel.com>,
 Declan Doherty <declan.doherty@intel.com>,
 Jerin Jacob <jerin.jacob@caviumnetworks.com>,
 Keith Wiles <keith.wiles@intel.com>,
 Stephen Hemminger <stephen@networkplumber.org>
To: Jan Viktorin <viktorin@rehivetech.com>
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On 6 May 2016 at 21:47, Jan Viktorin <viktorin@rehivetech.com> wrote:
> Generalize the PCI-specific pci_unbind_kernel_driver. It is now divided into
> two parts. First, determination of the path and string identification of the
> device to be unbound. Second, the actual unbind operation which is generic.
>
> Signed-off-by: Jan Viktorin <viktorin@rehivetech.com>
> ---
>  lib/librte_eal/common/eal_private.h   | 13 +++++++++++++
>  lib/librte_eal/linuxapp/eal/eal.c     | 26 ++++++++++++++++++++++++++
>  lib/librte_eal/linuxapp/eal/eal_pci.c | 33 +++++++++------------------------
>  3 files changed, 48 insertions(+), 24 deletions(-)
>
> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
> index 81816a6..3fb8353 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -289,6 +289,19 @@ int rte_eal_alarm_init(void);
>  int rte_eal_check_module(const char *module_name);
>
>  /**
> + * Unbind kernel driver bound to the device specified by the given devpath,
> + * and its string identification.
> + *
> + * @param devpath  path to the device directory ("/sys/.../devices/<name>")
> + * @param devid    identification of the device (<name>)
> + *
> + * @return
> + *      -1  unbind has failed
> + *       0  module has been unbound
> + */
> +int rte_eal_unbind_kernel_driver(const char *devpath, const char *devid);
> +
> +/**
>   * Get cpu core_id.
>   *
>   * This function is private to the EAL.
> diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
> index e8fce6b..844f958 100644
> --- a/lib/librte_eal/linuxapp/eal/eal.c
> +++ b/lib/librte_eal/linuxapp/eal/eal.c
> @@ -949,3 +949,29 @@ rte_eal_check_module(const char *module_name)
>         /* Module has been found */
>         return 1;
>  }
> +
> +int
> +rte_eal_unbind_kernel_driver(const char *devpath, const char *devid)
> +{
> +       char filename[PATH_MAX];
> +       FILE *f;
> +
> +       snprintf(filename, sizeof(filename),
> +                "%s/driver/unbind", devpath);
> +
> +       f = fopen(filename, "w");
> +       if (f == NULL) /* device was not bound */
> +               return 0;
> +
> +       if (fwrite(devid, strlen(devid), 1, f) == 0) {
> +               RTE_LOG(ERR, EAL, "%s(): could not write to %s\n", __func__,
> +                               filename);
> +               goto error;
> +       }
> +
> +       fclose(f);
> +       return 0;
> +error:
> +       fclose(f);
> +       return -1;
> +}
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
> index fd7e34f..312cb14 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
> @@ -59,38 +59,23 @@ int
>  pci_unbind_kernel_driver(struct rte_pci_device *dev)
>  {
>         int n;
> -       FILE *f;
> -       char filename[PATH_MAX];
> -       char buf[BUFSIZ];
> +       char devpath[PATH_MAX];
> +       char devid[BUFSIZ];
>         struct rte_pci_addr *loc = &dev->addr;
>
> -       /* open /sys/bus/pci/devices/AAAA:BB:CC.D/driver */
> -       snprintf(filename, sizeof(filename),
> -                SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/driver/unbind",
> +       /* devpath /sys/bus/pci/devices/AAAA:BB:CC.D */
> +       snprintf(devpath, sizeof(devpath),
> +                SYSFS_PCI_DEVICES "/" PCI_PRI_FMT,
>                  loc->domain, loc->bus, loc->devid, loc->function);
>
> -       f = fopen(filename, "w");
> -       if (f == NULL) /* device was not bound */
> -               return 0;
> -
> -       n = snprintf(buf, sizeof(buf), PCI_PRI_FMT "\n",
> +       n = snprintf(devid, sizeof(devid), PCI_PRI_FMT "\n",
>                      loc->domain, loc->bus, loc->devid, loc->function);
> -       if ((n < 0) || (n >= (int)sizeof(buf))) {
> +       if ((n < 0) || (n >= (int)sizeof(devid))) {

Is it better to move "(n >= (int)sizeof(devid))" before snprintf and
it has different reason from "n < 0"?

>                 RTE_LOG(ERR, EAL, "%s(): snprintf failed\n", __func__);
> -               goto error;
> -       }
> -       if (fwrite(buf, n, 1, f) == 0) {
> -               RTE_LOG(ERR, EAL, "%s(): could not write to %s\n", __func__,
> -                               filename);
> -               goto error;
> +               return -1;
>         }
>
> -       fclose(f);
> -       return 0;
> -
> -error:
> -       fclose(f);
> -       return -1;
> +       return rte_eal_unbind_kernel_driver(devpath, devid);
>  }
>
>  static int
> --
> 2.8.0
>