Commit 5c99eaec authored by Feras Daoud's avatar Feras Daoud Committed by Doug Ledford
Browse files

IB/mlx5: Mmap the HCA's clock info to user-space 



This patch maps the new page to user space applications to
allow converting a user space completion timestamp to system wall
time at the lowest possible latency cost.
By using a versioning scheme we allow compatibility between current
and future userspace libraries.
The change moves mlx5_ib_mmap_cmd enum from mlx5_ib.h to the
abi header file mlx5-abi.h.

Reviewed-by: default avatarAlex Vesker <valex@mellanox.com>
Reviewed-by: default avatarYishai Hadas <yishaih@mellanox.com>
Signed-off-by: default avatarFeras Daoud <ferasda@mellanox.com>
Signed-off-by: default avatarEitan Rabin <rabin@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 24d33d2c

drivers/infiniband/hw/mlx5/main.c

+42 −2
Original line number Diff line number Diff line
@@ -1579,6 +1579,7 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev, 
	struct mlx5_ib_dev *dev = to_mdev(ibdev);

	struct mlx5_ib_alloc_ucontext_req_v2 req = {};

	struct mlx5_ib_alloc_ucontext_resp resp = {};

	struct mlx5_core_dev *mdev = dev->mdev;

	struct mlx5_ib_ucontext *context;

	struct mlx5_bfreg_info *bfregi;

	int ver;
@@ -1706,6 +1707,12 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev, 
		resp.response_length += sizeof(resp.eth_min_inline);

	}



	if (field_avail(typeof(resp), clock_info_versions, udata->outlen)) {

		if (mdev->clock_info)

			resp.clock_info_versions = BIT(MLX5_IB_CLOCK_INFO_V1);

		resp.response_length += sizeof(resp.clock_info_versions);

	}



	/*

	 * We don't want to expose information from the PCI bar that is located

	 * after 4096 bytes, so if the arch only supports larger pages, let's
@@ -1719,8 +1726,7 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev, 
			resp.hca_core_clock_offset =

				offsetof(struct mlx5_init_seg, internal_timer_h) % PAGE_SIZE;

		}

		resp.response_length += sizeof(resp.hca_core_clock_offset) +

					sizeof(resp.reserved2);

		resp.response_length += sizeof(resp.hca_core_clock_offset);

	}



	if (field_avail(typeof(resp), log_uar_size, udata->outlen))
@@ -1959,6 +1965,38 @@ static inline char *mmap_cmd2str(enum mlx5_ib_mmap_cmd cmd) 
	}

}



static int mlx5_ib_mmap_clock_info_page(struct mlx5_ib_dev *dev,

					struct vm_area_struct *vma,

					struct mlx5_ib_ucontext *context)

{

	phys_addr_t pfn;

	int err;



	if (vma->vm_end - vma->vm_start != PAGE_SIZE)

		return -EINVAL;



	if (get_index(vma->vm_pgoff) != MLX5_IB_CLOCK_INFO_V1)

		return -EOPNOTSUPP;



	if (vma->vm_flags & VM_WRITE)

		return -EPERM;



	if (!dev->mdev->clock_info_page)

		return -EOPNOTSUPP;



	pfn = page_to_pfn(dev->mdev->clock_info_page);

	err = remap_pfn_range(vma, vma->vm_start, pfn, PAGE_SIZE,

			      vma->vm_page_prot);

	if (err)

		return err;



	mlx5_ib_dbg(dev, "mapped clock info at 0x%lx, PA 0x%llx\n",

		    vma->vm_start,

		    (unsigned long long)pfn << PAGE_SHIFT);



	return mlx5_ib_set_vma_data(vma, context);

}



static int uar_mmap(struct mlx5_ib_dev *dev, enum mlx5_ib_mmap_cmd cmd,

		    struct vm_area_struct *vma,

		    struct mlx5_ib_ucontext *context)
@@ -2121,6 +2159,8 @@ static int mlx5_ib_mmap(struct ib_ucontext *ibcontext, struct vm_area_struct *vm 
			    vma->vm_start,

			    (unsigned long long)pfn << PAGE_SHIFT);

		break;

	case MLX5_IB_MMAP_CLOCK_INFO:

		return mlx5_ib_mmap_clock_info_page(dev, vma, context);



	default:

		return -EINVAL;

drivers/infiniband/hw/mlx5/mlx5_ib.h

+0 −10
Original line number Diff line number Diff line
@@ -70,16 +70,6 @@ enum { 
	MLX5_IB_MMAP_CMD_MASK	= 0xff,

};



enum mlx5_ib_mmap_cmd {

	MLX5_IB_MMAP_REGULAR_PAGE		= 0,

	MLX5_IB_MMAP_GET_CONTIGUOUS_PAGES	= 1,

	MLX5_IB_MMAP_WC_PAGE			= 2,

	MLX5_IB_MMAP_NC_PAGE			= 3,

	/* 5 is chosen in order to be compatible with old versions of libmlx5 */

	MLX5_IB_MMAP_CORE_CLOCK			= 5,

	MLX5_IB_MMAP_ALLOC_WC			= 6,

};



enum {

	MLX5_RES_SCAT_DATA32_CQE	= 0x1,

	MLX5_RES_SCAT_DATA64_CQE	= 0x2,

include/uapi/rdma/mlx5-abi.h

+17 −1
Original line number Diff line number Diff line
@@ -124,7 +124,7 @@ struct mlx5_ib_alloc_ucontext_resp { 
	__u8	cqe_version;

	__u8	cmds_supp_uhw;

	__u8	eth_min_inline;

	__u8	reserved2;

	__u8	clock_info_versions;

	__u64	hca_core_clock_offset;

	__u32	log_uar_size;

	__u32	num_uars_per_page;
@@ -394,7 +394,23 @@ struct mlx5_ib_clock_info { 
	__u64 overflow_period;

};



enum mlx5_ib_mmap_cmd {

	MLX5_IB_MMAP_REGULAR_PAGE               = 0,

	MLX5_IB_MMAP_GET_CONTIGUOUS_PAGES       = 1,

	MLX5_IB_MMAP_WC_PAGE                    = 2,

	MLX5_IB_MMAP_NC_PAGE                    = 3,

	/* 5 is chosen in order to be compatible with old versions of libmlx5 */

	MLX5_IB_MMAP_CORE_CLOCK                 = 5,

	MLX5_IB_MMAP_ALLOC_WC                   = 6,

	MLX5_IB_MMAP_CLOCK_INFO                 = 7,

};



enum {

	MLX5_IB_CLOCK_INFO_KERNEL_UPDATING = 1,

};



/* Bit indexes for the mlx5_alloc_ucontext_resp.clock_info_versions bitmap */

enum {

	MLX5_IB_CLOCK_INFO_V1              = 0,

};

#endif /* MLX5_ABI_USER_H */

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