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

[Shreyansh jain]

On Thursday 14 July 2016 10:31 PM, Jan Viktorin wrote:
> On Tue, 12 Jul 2016 11:31:18 +0530
> Shreyansh Jain <shreyansh.jain at 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 at 6wind.com>
>> Signed-off-by: Shreyansh Jain <shreyansh.jain at 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?

My miss - I had though of using pci_get_sysfs_path post v5, (as you have mentioned below) but while re-creating the patches I missed out.

> 
>>  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?

Once pci_get_sysfs_path is used, this change would be redundant.

> 
>>  /**
>>   * 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.

My miss. I will change this.

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