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Commit d69e3bcf authored by Matan Barak's avatar Matan Barak Committed by Doug Ledford
Browse files

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



In order to read the HCA's current cycles register, we need
to map it to user-space. Add support to map this register
via mmap command.

Signed-off-by: default avatarMatan Barak <matanb@mellanox.com>
Reviewed-by: default avatarMoshe Lazer <moshel@mellanox.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent b368d7cb

drivers/infiniband/hw/mlx5/main.c

+28 −0
Original line number Diff line number Diff line
@@ -1023,6 +1023,34 @@ static int mlx5_ib_mmap(struct ib_ucontext *ibcontext, struct vm_area_struct *vm 
	case MLX5_IB_MMAP_GET_CONTIGUOUS_PAGES:

		return -ENOSYS;



	case MLX5_IB_MMAP_CORE_CLOCK:

	{

		phys_addr_t pfn;



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

			return -EINVAL;



		if (vma->vm_flags & (VM_WRITE | VM_EXEC))

			return -EPERM;



		/* Don't expose to user-space information it shouldn't have */

		if (PAGE_SIZE > 4096)

			return -EOPNOTSUPP;



		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

		pfn = (dev->mdev->iseg_base +

		       offsetof(struct mlx5_init_seg, internal_timer_h)) >>

			PAGE_SHIFT;

		if (io_remap_pfn_range(vma, vma->vm_start, pfn,

				       PAGE_SIZE, vma->vm_page_prot))

			return -EAGAIN;



		mlx5_ib_dbg(dev, "mapped internal timer at 0x%lx, PA 0x%llx\n",

			    vma->vm_start,

			    (unsigned long long)pfn << PAGE_SHIFT);

		break;

	}



	default:

		return -EINVAL;

	}

drivers/infiniband/hw/mlx5/mlx5_ib.h

+3 −1
Original line number Diff line number Diff line
@@ -65,7 +65,9 @@ enum { 


enum mlx5_ib_mmap_cmd {

	MLX5_IB_MMAP_REGULAR_PAGE		= 0,

	MLX5_IB_MMAP_GET_CONTIGUOUS_PAGES	= 1, /* always last */

	MLX5_IB_MMAP_GET_CONTIGUOUS_PAGES	= 1,

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

	MLX5_IB_MMAP_CORE_CLOCK			= 5,

};



enum {