[dpdk-dev] [PATCH v4 06/12] bus: get iommu class

[santosh]

Hi Hemant,

On Tuesday 18 July 2017 04:35 PM, Hemant Agrawal wrote:

> On 7/18/2017 11:29 AM, Santosh Shukla wrote:
>> API(rte_bus_get_iommu_class) helps to automatically detect and select
>> appropriate iova mapping scheme for iommu capable device on that bus.
>>
>> Algorithm for iova scheme selection for bus:
>> 0. Iterate through bus_list.
>> 1. Collect each bus iova mode value and update into 'mode' var.
>> 2. Mode selection scheme is:
>> if mode == 0 then iova mode is _pa,
>> if mode == 1 then iova mode is _pa,
>> if mode == 2 then iova mode is _va,
>> if mode == 3 then iova mode ia _pa.
>>
>> So mode !=2  will be default iova mode (_pa).
>>
>> Signed-off-by: Santosh Shukla <santosh.shukla at caviumnetworks.com>
>> Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
>> ---
>> v3 --> v4:
>>  - Initialized mode to RTE_IOVA_DC in rte_bus_get_iommu_class.
>>
>>  lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  1 +
>>  lib/librte_eal/common/eal_common_bus.c          | 23 +++++++++++++++++++++++
>>  lib/librte_eal/common/eal_common_pci.c          |  1 +
>>  lib/librte_eal/common/include/rte_bus.h         | 22 ++++++++++++++++++++++
>>  lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
>>  5 files changed, 48 insertions(+)
>>
>> diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
>> index 4b25318be..b9ee82b6b 100644
>> --- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
>> +++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
>> @@ -202,6 +202,7 @@ DPDK_17.08 {
>>      rte_bus_find_by_name;
>>      rte_pci_match;
>>      rte_pci_get_iommu_class;
>> +    rte_bus_get_iommu_class;
>>
>>  } DPDK_17.05;
>>
>> diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
>> index 08bec2d93..a30a8982e 100644
>> --- a/lib/librte_eal/common/eal_common_bus.c
>> +++ b/lib/librte_eal/common/eal_common_bus.c
>> @@ -222,3 +222,26 @@ rte_bus_find_by_device_name(const char *str)
>>          c[0] = '\0';
>>      return rte_bus_find(NULL, bus_can_parse, name);
>>  }
>> +
>> +
>> +/*
>> + * Get iommu class of devices on the bus.
>> + */
>> +enum rte_iova_mode
>> +rte_bus_get_iommu_class(void)
>> +{
>> +    int mode = RTE_IOVA_DC;
>> +    struct rte_bus *bus;
>> +
>> +    TAILQ_FOREACH(bus, &rte_bus_list, next) {
>> +
>> +        if (bus->get_iommu_class)
>> +            mode |= bus->get_iommu_class();
>> +    }
>> +
>> +    if (mode != RTE_IOVA_VA) {
>> +        /* Use default IOVA mode */
>> +        mode = RTE_IOVA_PA;
>> +    }
>> +    return mode;
>> +}
>> diff --git a/lib/librte_eal/common/eal_common_pci.c b/lib/librte_eal/common/eal_common_pci.c
>> index 8b6ecebd6..bdf2e7c3a 100644
>> --- a/lib/librte_eal/common/eal_common_pci.c
>> +++ b/lib/librte_eal/common/eal_common_pci.c
>> @@ -552,6 +552,7 @@ struct rte_pci_bus rte_pci_bus = {
>>          .plug = pci_plug,
>>          .unplug = pci_unplug,
>>          .parse = pci_parse,
>> +        .get_iommu_class = rte_pci_get_iommu_class,
>>      },
>>      .device_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.device_list),
>>      .driver_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.driver_list),
>> diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
>> index e06084253..94f1fdfca 100644
>> --- a/lib/librte_eal/common/include/rte_bus.h
>> +++ b/lib/librte_eal/common/include/rte_bus.h
>> @@ -182,6 +182,17 @@ struct rte_bus_conf {
>>      enum rte_bus_scan_mode scan_mode; /**< Scan policy. */
>>  };
>>
>> +
>> +/**
>> + * Get iommu class of devices on the bus.
>> + * Check that those devices are attached to iommu driver.
>
> Can we try to improve this description.
> " Get common iommu class of the all the devices on the bus. Bus may check that those devices are attached to iommu driver.
> If not devices are attached to the bus. Bus may return with don't core value."
>
> otherwise
> Acked-by: Hemant Agrawal <hemant.agrawal at nxp.com>
>
We'll reword description in v5. Thanks for suggestion.

>> + *
>> + * @return
>> + *      enum rte_iova_mode value.
>> + */
>> +typedef enum rte_iova_mode (*rte_bus_get_iommu_class_t)(void);
>> +
>> +
>>  /**
>>   * A structure describing a generic bus.
>>   */
>> @@ -195,6 +206,7 @@ struct rte_bus {
>>      rte_bus_unplug_t unplug;     /**< Remove single device from driver */
>>      rte_bus_parse_t parse;       /**< Parse a device name */
>>      struct rte_bus_conf conf;    /**< Bus configuration */
>> +    rte_bus_get_iommu_class_t get_iommu_class; /**< Get iommu class */
>>  };
>>
>>  /**
>> @@ -294,6 +306,16 @@ struct rte_bus *rte_bus_find_by_device(const struct rte_device *dev);
>>   */
>>  struct rte_bus *rte_bus_find_by_name(const char *busname);
>>
>> +
>> +/**
>> + * Get iommu class of devices on the bus.
>> + * Check that those devices are attached to iommu driver.
>
> Get the common iommu class of devices bound on to buses available in the system. The default mode is PA.
>
ditto... in v5.

>> + *
>> + * @return
>> + *     enum rte_iova_mode value.
>> + */
>> +enum rte_iova_mode rte_bus_get_iommu_class(void);
>> +
>>  /**
>>   * Helper for Bus registration.
>>   * The constructor has higher priority than PMD constructors.
>> diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
>> index 5dd40f948..705af3adc 100644
>> --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
>> +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
>> @@ -207,6 +207,7 @@ DPDK_17.08 {
>>      rte_bus_find_by_name;
>>      rte_pci_match;
>>      rte_pci_get_iommu_class;
>> +    rte_bus_get_iommu_class;
>>
>>  } DPDK_17.05;
>>
>>
>
>