Thanks Jerin, comment inline
On 2021/7/20 13:03, Jerin Jacob wrote:
> On Tue, Jul 20, 2021 at 6:48 AM Chengwen Feng <fengcheng...@huawei.com> wrote:
>>
>> This patch introduce 'dmadevice' which is a generic type of DMA
>> device.
>>
>> The APIs of dmadev library exposes some generic operations which can
>> enable configuration and I/O with the DMA devices.
>>
>> Signed-off-by: Chengwen Feng <fengcheng...@huawei.com>
[snip]
>> +int
>> +rte_dmadev_info_get(uint16_t dev_id, struct rte_dmadev_info *dev_info)
>> +{
>> + const struct rte_dmadev *dev = &rte_dmadevices[dev_id];
>> + int ret;
>> +
>> + RTE_DMADEV_VALID_DEV_ID_OR_ERR_RET(dev_id, -EINVAL);
>> + if (dev_info == NULL)
>> + return -EINVAL;
>> +
>> + RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_info_get, -ENOTSUP);
>> + memset(dev_info, 0, sizeof(struct rte_dmadev_info));
>> + ret = (*dev->dev_ops->dev_info_get)(dev, dev_info,
>> + sizeof(struct rte_dmadev_info));
>> + if (ret != 0)
>> + return ret;
>> +
>> + dev_info->device = dev->device;
>> + dev_info->nb_vchans = dev->data->dev_conf.max_vchans;
>
> This will be updated after configure stage.
Yes, the dev_info->nb_vchans hold the number of virtual DMA channel configured.
Do you mean add one comment here ?
>
>
>> +
>> + return 0;
>> +}
>> +
>> +int
>> +rte_dmadev_configure(uint16_t dev_id, const struct rte_dmadev_conf
>> *dev_conf)
>> +{
>> + struct rte_dmadev *dev = &rte_dmadevices[dev_id];
>> + struct rte_dmadev_info info;
>> + int ret;
>> +
>> + RTE_DMADEV_VALID_DEV_ID_OR_ERR_RET(dev_id, -EINVAL);
>> + if (dev_conf == NULL)
>> + return -EINVAL;
>> +
>> + ret = rte_dmadev_info_get(dev_id, &info);
>> + if (ret != 0) {
>> + RTE_DMADEV_LOG(ERR, "Device %u get device info fail\n",
>> dev_id);
>> + return -EINVAL;
>> + }
>> + if (dev_conf->max_vchans == 0) {
>> + RTE_DMADEV_LOG(ERR,
>> + "Device %u configure zero vchans\n", dev_id);
>> + return -EINVAL;
>> + }
>> + if (dev_conf->max_vchans > info.max_vchans) {
>> + RTE_DMADEV_LOG(ERR,
>> + "Device %u configure too many vchans\n", dev_id);
>> + return -EINVAL;
>> + }
>> + if (dev_conf->enable_silent &&
>> + !(info.dev_capa & RTE_DMADEV_CAPA_SILENT)) {
>> + RTE_DMADEV_LOG(ERR, "Device %u don't support silent\n",
>> dev_id);
>> + return -EINVAL;
>> + }
>> +
>> + if (dev->data->dev_started != 0) {
>> + RTE_DMADEV_LOG(ERR,
>> + "Device %u must be stopped to allow configuration\n",
>> + dev_id);
>> + return -EBUSY;
>> + }
>
> ethdev and other device class common code handles the reconfigure case. i.e
> the application configures N vchan first and reconfigures to N - M
> then free the resources
> attached to M - N. Please do the same here.
DMA is a simple device, I think it's OK to reconfigure at driver-level.
PS: If we need support reconfigure at dmadev-level, dmadev should hold the
vchan-configuration,
and invoke driver's vchan_release to release resources. This may introduce more
complexity.
>> +int
>> +rte_dmadev_dump(uint16_t dev_id, FILE *f)
>> +{
>> + const struct rte_dmadev *dev = &rte_dmadevices[dev_id];
>> + struct rte_dmadev_info info;
>> + int ret;
>> +
>> + RTE_DMADEV_VALID_DEV_ID_OR_ERR_RET(dev_id, -EINVAL);
>> + if (f == NULL)
>> + return -EINVAL;
>> +
>> + ret = rte_dmadev_info_get(dev_id, &info);
>> + if (ret != 0) {
>> + RTE_DMADEV_LOG(ERR, "Device %u get device info fail\n",
>> dev_id);
>> + return -EINVAL;
>> + }
>> +
>> + fprintf(f, "DMA Dev %u, '%s' [%s]\n",
>> + dev->data->dev_id,
>> + dev->data->dev_name,
>> + dev->data->dev_started ? "started" : "stopped");
>> + fprintf(f, " dev_capa: 0x%" PRIx64 "\n", info.dev_capa);
>> + fprintf(f, " max_vchans_supported: %u\n", info.max_vchans);
>> + fprintf(f, " max_vchans_configured: %u\n", info.nb_vchans);
>> + fprintf(f, " silent_mode: %s\n",
>> + dev->data->dev_conf.enable_silent ? "on" : "off");
>
> Probably iterate over each vchan and dumping the at least direction
> will be usefull.
dmadev hasn't hold vchan-configuration, Need more discussion.
