Re: [PATCH 11/15] RDMA/hbl: add habanalabs RDMA driver

Leon Romanovsky
2024-06-13T19:18:33Z

On Thu, Jun 13, 2024 at 11:22:04AM +0300, Omer Shpigelman wrote:
> Add an RDMA driver of Gaudi ASICs family for AI scaling.
> The driver itself is agnostic to the ASIC in action, it operates according
> to the capabilities that were passed on device initialization.
> The device is initialized by the hbl_cn driver via auxiliary bus.
> The driver also supports QP resource tracking and port/device HW counters.
>
> Signed-off-by: Omer Shpigelman <oshpigelman@habana.ai>
> Co-developed-by: Abhilash K V <kvabhilash@habana.ai>
> Signed-off-by: Abhilash K V <kvabhilash@habana.ai>
> Co-developed-by: Andrey Agranovich <aagranovich@habana.ai>
> Signed-off-by: Andrey Agranovich <aagranovich@habana.ai>
> Co-developed-by: Bharat Jauhari <bjauhari@habana.ai>
> Signed-off-by: Bharat Jauhari <bjauhari@habana.ai>
> Co-developed-by: David Meriin <dmeriin@habana.ai>
> Signed-off-by: David Meriin <dmeriin@habana.ai>
> Co-developed-by: Sagiv Ozeri <sozeri@habana.ai>
> Signed-off-by: Sagiv Ozeri <sozeri@habana.ai>
> Co-developed-by: Zvika Yehudai <zyehudai@habana.ai>
> Signed-off-by: Zvika Yehudai <zyehudai@habana.ai>

I afraid that you misinterpreted the "Co-developed-by" tag. All these
people are probably touch the code and not actually sit together at
the same room and write the code together. So, please remove the
extensive "Co-developed-by" tags.

It is not full review yet, but simple pass-by-comments.

> ---
> MAINTAINERS | 10 +
> drivers/infiniband/Kconfig | 1 +
> drivers/infiniband/hw/Makefile | 1 +
> drivers/infiniband/hw/hbl/Kconfig | 17 +
> drivers/infiniband/hw/hbl/Makefile | 8 +
> drivers/infiniband/hw/hbl/hbl.h | 326 +++
> drivers/infiniband/hw/hbl/hbl_main.c | 478 ++++
> drivers/infiniband/hw/hbl/hbl_verbs.c | 2686 ++++++++++++++++++++++
> include/uapi/rdma/hbl-abi.h | 204 ++
> include/uapi/rdma/hbl_user_ioctl_cmds.h | 66 +
> include/uapi/rdma/hbl_user_ioctl_verbs.h | 106 +
> include/uapi/rdma/ib_user_ioctl_verbs.h | 1 +
> 12 files changed, 3904 insertions(+)
> create mode 100644 drivers/infiniband/hw/hbl/Kconfig
> create mode 100644 drivers/infiniband/hw/hbl/Makefile
> create mode 100644 drivers/infiniband/hw/hbl/hbl.h
> create mode 100644 drivers/infiniband/hw/hbl/hbl_main.c
> create mode 100644 drivers/infiniband/hw/hbl/hbl_verbs.c
> create mode 100644 include/uapi/rdma/hbl-abi.h
> create mode 100644 include/uapi/rdma/hbl_user_ioctl_cmds.h
> create mode 100644 include/uapi/rdma/hbl_user_ioctl_verbs.h

<...>

> +#define hbl_ibdev_emerg(ibdev, format, ...) ibdev_emerg(ibdev, format, ##__VA_ARGS__)
> +#define hbl_ibdev_alert(ibdev, format, ...) ibdev_alert(ibdev, format, ##__VA_ARGS__)
> +#define hbl_ibdev_crit(ibdev, format, ...) ibdev_crit(ibdev, format, ##__VA_ARGS__)
> +#define hbl_ibdev_err(ibdev, format, ...) ibdev_err(ibdev, format, ##__VA_ARGS__)
> +#define hbl_ibdev_warn(ibdev, format, ...) ibdev_warn(ibdev, format, ##__VA_ARGS__)
> +#define hbl_ibdev_notice(ibdev, format, ...) ibdev_notice(ibdev, format, ##__VA_ARGS__)
> +#define hbl_ibdev_info(ibdev, format, ...) ibdev_info(ibdev, format, ##__VA_ARGS__)
> +#define hbl_ibdev_dbg(ibdev, format, ...) ibdev_dbg(ibdev, format, ##__VA_ARGS__)
> +
> +#define hbl_ibdev_emerg_ratelimited(ibdev, fmt, ...) \
> + ibdev_emerg_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +#define hbl_ibdev_alert_ratelimited(ibdev, fmt, ...) \
> + ibdev_alert_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +#define hbl_ibdev_crit_ratelimited(ibdev, fmt, ...) \
> + ibdev_crit_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +#define hbl_ibdev_err_ratelimited(ibdev, fmt, ...) \
> + ibdev_err_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +#define hbl_ibdev_warn_ratelimited(ibdev, fmt, ...) \
> + ibdev_warn_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +#define hbl_ibdev_notice_ratelimited(ibdev, fmt, ...) \
> + ibdev_notice_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +#define hbl_ibdev_info_ratelimited(ibdev, fmt, ...) \
> + ibdev_info_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +#define hbl_ibdev_dbg_ratelimited(ibdev, fmt, ...) \
> + ibdev_dbg_ratelimited(ibdev, fmt, ##__VA_ARGS__)
> +

Please don't redefine the existing macros. Just use the existing ones.

<...>

> + if (hbl_ib_match_netdev(ibdev, netdev))
> + ib_port = hbl_to_ib_port_num(hdev, netdev->dev_port);
> + else
> + return NOTIFY_DONE;

It is not kernel coding style. Please write:
if (!hbl_ib_match_netdev(ibdev, netdev))
return NOTIFY_DONE;

ib_port = hbl_to_ib_port_num(hdev, netdev->dev_port);

> +

<...>

> +static int hbl_ib_probe(struct auxiliary_device *adev, const struct auxiliary_device_id *id)
> +{
> + struct hbl_aux_dev *aux_dev = container_of(adev, struct hbl_aux_dev, adev);
> + struct hbl_ib_aux_ops *aux_ops = aux_dev->aux_ops;
> + struct hbl_ib_device *hdev;
> + ktime_t timeout;
> + int rc;
> +
> + rc = hdev_init(aux_dev);
> + if (rc) {
> + dev_err(&aux_dev->adev.dev, "Failed to init hdev\n");
> + return -EIO;
> + }
> +
> + hdev = aux_dev->priv;
> +
> + /* don't allow module unloading while it is attached */
> + if (!try_module_get(THIS_MODULE)) {

This part makes wonder, what are you trying to do here? What doesn't work for you
in standard driver core and module load mechanism?

> + dev_err(hdev->dev, "Failed to increment %s module refcount\n",
> + module_name(THIS_MODULE));
> + rc = -EIO;
> + goto module_get_err;
> + }
> +
> + timeout = ktime_add_ms(ktime_get(), hdev->pending_reset_long_timeout * MSEC_PER_SEC);
> + while (1) {
> + aux_ops->hw_access_lock(aux_dev);
> +
> + /* if the device is operational, proceed to actual init while holding the lock in
> + * order to prevent concurrent hard reset
> + */
> + if (aux_ops->device_operational(aux_dev))
> + break;
> +
> + aux_ops->hw_access_unlock(aux_dev);
> +
> + if (ktime_compare(ktime_get(), timeout) > 0) {
> + dev_err(hdev->dev, "Timeout while waiting for hard reset to finish\n");
> + rc = -EBUSY;
> + goto timeout_err;
> + }
> +
> + dev_notice_once(hdev->dev, "Waiting for hard reset to finish before probing IB\n");
> +
> + msleep_interruptible(MSEC_PER_SEC);
> + }

The code above is unexpected.

> +
> + rc = hbl_ib_dev_init(hdev);
> + if (rc) {
> + dev_err(hdev->dev, "Failed to init ib device\n");
> + goto dev_init_err;
> + }
> +
> + aux_ops->hw_access_unlock(aux_dev);
> +
> + return 0;
> +
> +dev_init_err:
> + aux_ops->hw_access_unlock(aux_dev);
> +timeout_err:
> + module_put(THIS_MODULE);
> +module_get_err:
> + hdev_fini(aux_dev);
> +
> + return rc;
> +}

<...>

> +static int __init hbl_ib_init(void)
> +{
> + pr_info("loading driver\n");

Please remove all these debug prints and leave only the necessary ones.

> +
> + return auxiliary_driver_register(&hbl_ib_driver);
> +}
> +
> +static void __exit hbl_ib_exit(void)
> +{
> + auxiliary_driver_unregister(&hbl_ib_driver);
> +
> + pr_info("driver removed\n");
> +}
> +
> +module_init(hbl_ib_init);
> +module_exit(hbl_ib_exit)

Thanks