Re: [dpdk-dev] [PATCH v6 13/17] pci: add a helper to update a device

[Jan Viktorin <viktorin@rehivetech.com>]

On Tue, 12 Jul 2016 11:31:18 +0530
Shreyansh Jain <shreyansh.jain@nxp.com> wrote:

> This helper updates a pci device object with latest information it can
> find.
> It will be used mainly for hotplug code.
> 
> Signed-off-by: David Marchand <david.marchand@6wind.com>
> Signed-off-by: Shreyansh Jain <shreyansh.jain@nxp.com>
> ---
>  lib/librte_eal/bsdapp/eal/eal_pci.c     | 49 +++++++++++++++++++++++++++++++++
>  lib/librte_eal/common/eal_common_pci.c  |  2 --
>  lib/librte_eal/common/eal_private.h     | 13 +++++++++
>  lib/librte_eal/common/include/rte_pci.h |  3 ++
>  lib/librte_eal/linuxapp/eal/eal_pci.c   | 13 +++++++++
>  5 files changed, 78 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
> index a73cbb0..1d91c78 100644
> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c
> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
> @@ -406,6 +406,55 @@ error:
>  	return -1;
>  }
>  
> +int
> +pci_update_device(const struct rte_pci_addr *addr)
> +{
> +	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);
> +	if (fd < 0) {
> +		RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__);
> +		goto error;
> +	}
> +
> +	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:
> +	if (fd >= 0)
> +		close(fd);
> +	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_common_pci.c b/lib/librte_eal/common/eal_common_pci.c
> index 6a0f6ac..58f0c74 100644
> --- a/lib/librte_eal/common/eal_common_pci.c
> +++ b/lib/librte_eal/common/eal_common_pci.c
> @@ -87,8 +87,6 @@ struct pci_driver_list pci_driver_list =
>  struct pci_device_list pci_device_list =
>  	TAILQ_HEAD_INITIALIZER(pci_device_list);
>  
> -#define SYSFS_PCI_DEVICES "/sys/bus/pci/devices"
> -

Is this delete correct? The SYSFS_PCI_DEVICES was moved here from
rte_pci.h. A relict of some rebase?

>  const char *pci_get_sysfs_path(void)
>  {
>  	const char *path = NULL;
> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
> index 06a68f6..b8ff9c5 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -152,6 +152,19 @@ struct rte_pci_driver;
>  struct rte_pci_device;
>  
>  /**
> + * Update 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.
> + */
> +int pci_update_device(const struct rte_pci_addr *addr);
> +
> +/**
>   * Unbind kernel driver for this device
>   *
>   * This function is private to EAL.
> diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
> index 06508fa..5c2062c 100644
> --- a/lib/librte_eal/common/include/rte_pci.h
> +++ b/lib/librte_eal/common/include/rte_pci.h
> @@ -107,6 +107,9 @@ const char *pci_get_sysfs_path(void);
>  /** Nb. of values in PCI resource format. */
>  #define PCI_RESOURCE_FMT_NVAL 3
>  
> +/** Default sysfs path for PCI device search. */
> +#define SYSFS_PCI_DEVICES "/sys/bus/pci/devices"
> +

Why adding SYSFS_PCI_DEVICES here? The pci_get_sysfs_path is used for
this purpose. Again, a rebase issue?

>  /**
>   * A structure describing a PCI resource.
>   */
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
> index f0215ee..8f3ef20 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
> @@ -417,6 +417,19 @@ pci_scan_one(const char *dirname, uint16_t domain, uint8_t bus,
>  	return 0;
>  }
>  
> +int
> +pci_update_device(const struct rte_pci_addr *addr)
> +{
> +	char filename[PATH_MAX];
> +
> +	snprintf(filename, sizeof(filename), "%s/" PCI_PRI_FMT,
> +		 SYSFS_PCI_DEVICES, addr->domain, addr->bus, addr->devid,

Use pci_get_sysfs_path here.

> +		 addr->function);
> +
> +	return pci_scan_one(filename, addr->domain, addr->bus, addr->devid,
> +			    addr->function);
> +}
> +
>  /*
>   * split up a pci address into its constituent parts.
>   */



-- 
  Jan Viktorin                E-mail: Viktorin@RehiveTech.com
  System Architect            Web:    www.RehiveTech.com
  RehiveTech
  Brno, Czech Republic