Re: [PATCH rdma-next 2/2] RDMA/mana_ib: Implement get_dma_mr

[Zhu Yanjun <zyjzyj2000@gmail.com>]

On 17.04.24 16:20, Konstantin Taranov wrote:
> From: Konstantin Taranov <kotaranov@microsoft.com>
> 
> Implement allocation of DMA-mapped memory regions.
> 
> Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
> ---
>   drivers/infiniband/hw/mana/device.c |  1 +
>   drivers/infiniband/hw/mana/mr.c     | 36 +++++++++++++++++++++++++++++
>   include/net/mana/gdma.h             |  5 ++++
>   3 files changed, 42 insertions(+)
> 
> diff --git a/drivers/infiniband/hw/mana/device.c b/drivers/infiniband/hw/mana/device.c
> index 6fa902ee80a6..043cef09f1c2 100644
> --- a/drivers/infiniband/hw/mana/device.c
> +++ b/drivers/infiniband/hw/mana/device.c
> @@ -29,6 +29,7 @@ static const struct ib_device_ops mana_ib_dev_ops = {
>   	.destroy_rwq_ind_table = mana_ib_destroy_rwq_ind_table,
>   	.destroy_wq = mana_ib_destroy_wq,
>   	.disassociate_ucontext = mana_ib_disassociate_ucontext,
> +	.get_dma_mr = mana_ib_get_dma_mr,
>   	.get_port_immutable = mana_ib_get_port_immutable,
>   	.mmap = mana_ib_mmap,
>   	.modify_qp = mana_ib_modify_qp,
> diff --git a/drivers/infiniband/hw/mana/mr.c b/drivers/infiniband/hw/mana/mr.c
> index 4f13423ecdbd..7c9394926a18 100644
> --- a/drivers/infiniband/hw/mana/mr.c
> +++ b/drivers/infiniband/hw/mana/mr.c
> @@ -8,6 +8,8 @@
>   #define VALID_MR_FLAGS                                                         \
>   	(IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE | IB_ACCESS_REMOTE_READ)
>   
> +#define VALID_DMA_MR_FLAGS IB_ACCESS_LOCAL_WRITE
> +
>   static enum gdma_mr_access_flags
>   mana_ib_verbs_to_gdma_access_flags(int access_flags)
>   {
> @@ -39,6 +41,8 @@ static int mana_ib_gd_create_mr(struct mana_ib_dev *dev, struct mana_ib_mr *mr,
>   	req.mr_type = mr_params->mr_type;
>   
>   	switch (mr_params->mr_type) {
> +	case GDMA_MR_TYPE_GPA:
> +		break;
>   	case GDMA_MR_TYPE_GVA:
>   		req.gva.dma_region_handle = mr_params->gva.dma_region_handle;
>   		req.gva.virtual_address = mr_params->gva.virtual_address;
> @@ -168,6 +172,38 @@ struct ib_mr *mana_ib_reg_user_mr(struct ib_pd *ibpd, u64 start, u64 length,
>   	return ERR_PTR(err);
>   }
>   

Not sure if the following function needs comments or not.
If yes, the kernel doc 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/doc-guide/kernel-doc.rst?h=v6.9-rc4#n67 
can provide a good example.

Best Regards,
Zhu Yanjun

> +struct ib_mr *mana_ib_get_dma_mr(struct ib_pd *ibpd, int access_flags)
> +{
> +	struct mana_ib_pd *pd = container_of(ibpd, struct mana_ib_pd, ibpd);
> +	struct gdma_create_mr_params mr_params = {};
> +	struct ib_device *ibdev = ibpd->device;
> +	struct mana_ib_dev *dev;
> +	struct mana_ib_mr *mr;
> +	int err;
> +
> +	dev = container_of(ibdev, struct mana_ib_dev, ib_dev);
> +
> +	if (access_flags & ~VALID_DMA_MR_FLAGS)
> +		return ERR_PTR(-EINVAL);
> +
> +	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
> +	if (!mr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	mr_params.pd_handle = pd->pd_handle;
> +	mr_params.mr_type = GDMA_MR_TYPE_GPA;
> +
> +	err = mana_ib_gd_create_mr(dev, mr, &mr_params);
> +	if (err)
> +		goto err_free;
> +
> +	return &mr->ibmr;
> +
> +err_free:
> +	kfree(mr);
> +	return ERR_PTR(err);
> +}
> +
>   int mana_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
>   {
>   	struct mana_ib_mr *mr = container_of(ibmr, struct mana_ib_mr, ibmr);
> diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
> index 8d796a30ddde..dc19b5cb33a6 100644
> --- a/include/net/mana/gdma.h
> +++ b/include/net/mana/gdma.h
> @@ -788,6 +788,11 @@ struct gdma_destory_pd_resp {
>   };/* HW DATA */
>   
>   enum gdma_mr_type {
> +	/*
> +	 * Guest Physical Address - MRs of this type allow access
> +	 * to any DMA-mapped memory using bus-logical address
> +	 */
> +	GDMA_MR_TYPE_GPA = 1,
>   	/* Guest Virtual Address - MRs of this type allow access
>   	 * to memory mapped by PTEs associated with this MR using a virtual
>   	 * address that is set up in the MST