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: Alex Vesker <valex@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Eitan Rabin <rabin@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Feras Daoud 2018-01-16 20:08:41 +02:00 committed by Doug Ledford
parent 24d33d2c8e
commit 5c99eaecb1
3 changed files with 59 additions and 13 deletions

View file

@ -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;

View file

@ -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,

View file

@ -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 */