Re: [PATCH 1/2] ethdev: add callback to get register size in bytes

[Zyta Szpak <zr@semihalf.com>]

On 27.05.2016 12:28, Panu Matilainen wrote:
> On 05/25/2016 09:36 AM, zr@semihalf.com wrote:
>> From: Zyta Szpak <zr@semihalf.com>
>>
>> Version 2 of fixing the fixed register width assumption.
>> rte_eth_dev_get_reg_length and rte_eth_dev_get_reg callbacks
>> do not provide register size to the app in any way. It is
>> needed to allocate proper number of bytes before retrieving
>> registers content with rte_eth_dev_get_reg.
>>
>> Signed-off-by: Zyta Szpak <zr@semihalf.com>
>> ---
>>  lib/librte_ether/rte_ethdev.c | 12 ++++++++++++
>>  lib/librte_ether/rte_ethdev.h | 18 ++++++++++++++++++
>>  2 files changed, 30 insertions(+)
>>
>> diff --git a/lib/librte_ether/rte_ethdev.c 
>> b/lib/librte_ether/rte_ethdev.c
>> index a31018e..e0765f8 100644
>> --- a/lib/librte_ether/rte_ethdev.c
>> +++ b/lib/librte_ether/rte_ethdev.c
>> @@ -3231,6 +3231,18 @@ rte_eth_dev_get_reg_length(uint8_t port_id)
>>  }
>>
>>  int
>> +rte_eth_dev_get_reg_width(uint8_t port_id)
>> +{
>> +    struct rte_eth_dev *dev;
>> +
>> +    RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
>> +
>> +    dev = &rte_eth_devices[port_id];
>> +    RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->get_reg_width, -ENOTSUP);
>> +    return (*dev->dev_ops->get_reg_width)(dev);
>> +}
>> +
>> +int
>>  rte_eth_dev_get_reg_info(uint8_t port_id, struct rte_dev_reg_info 
>> *info)
>>  {
>>      struct rte_eth_dev *dev;
>> diff --git a/lib/librte_ether/rte_ethdev.h 
>> b/lib/librte_ether/rte_ethdev.h
>> index 2757510..552eaed 100644
>> --- a/lib/librte_ether/rte_ethdev.h
>> +++ b/lib/librte_ether/rte_ethdev.h
>> @@ -1292,6 +1292,9 @@ typedef int (*eth_timesync_write_time)(struct 
>> rte_eth_dev *dev,
>>  typedef int (*eth_get_reg_length_t)(struct rte_eth_dev *dev);
>>  /**< @internal Retrieve device register count  */
>>
>> +typedef int (*eth_get_reg_width_t)(struct rte_eth_dev *dev);
>> +/**< @internal Retrieve device register byte number */
>> +
>>  typedef int (*eth_get_reg_t)(struct rte_eth_dev *dev,
>>                  struct rte_dev_reg_info *info);
>>  /**< @internal Retrieve registers  */
>> @@ -1455,6 +1458,8 @@ struct eth_dev_ops {
>>
>>      eth_get_reg_length_t get_reg_length;
>>      /**< Get # of registers */
>> +    eth_get_reg_width_t get_reg_width;
>> +    /**< Get # of bytes in register */
>>      eth_get_reg_t get_reg;
>>      /**< Get registers */
>>      eth_get_eeprom_length_t get_eeprom_length;
>
> This is an ABI break, but maybe it is part of that "driver 
> implementation API" which is exempt from the ABI/API policies. Thomas?
>
>> @@ -3971,6 +3976,19 @@ int rte_eth_tx_queue_info_get(uint8_t port_id, 
>> uint16_t queue_id,
>>   */
>>  int rte_eth_dev_get_reg_length(uint8_t port_id);
>>
>> +/*
>> + * Retrieve the number of bytes in register for a specific device
>> + *
>> + * @param port_id
>> + *   The port identifier of the Ethernet device.
>> + * @return
>> + *   - (>=0) number of registers if successful.
>> + *   - (-ENOTSUP) if hardware doesn't support.
>> + *   - (-ENODEV) if *port_id* invalid.
>> + *   - others depends on the specific operations implementation.
>> + */
>> +int rte_eth_dev_get_reg_width(uint8_t port_id);
>> +
>>  /**
>>   * Retrieve device registers and register attributes
>>   *
>
> The function needs to be exported via rte_ether_version.map as well.
OK, right!
>
>     - Panu -
>>
>